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  • 1. Andrén, Lars
    et al.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Lennermo, Gunnar
    Handbok för kombinerade sol- och biovärmesystem: Teknik - System - Ekonomi2012Report (Other academic)
    Abstract [sv]

    Handboken beskriver olika solfångarkonstruktioner och solvärmekretsens ingående komponenter och ger en grundlig inblick i ackumulatortankens konstruktion och funktion. I boken finns förslag på systemutformning, olika tekniska lösningar och hur systemen bör styras och regleras. Handboken beskriver i första hand utformning-lösning-styrning av kombinationen sol- och pelletsvärme, men tar även upp solvärme i kombination med vedpannor, värmedrivna vitvaror och värmepumpar. Värmesystem med vattenburen värme är utmärkta att kombinera med solvärme, men det är i de flesta fall enklare att få till bra lösningar vid nyinstallation, än vid komplettering av befintlig anläggning. När solvärme och pelletsvärme ska kombineras finns det många alternativ till systemutformning. Det är viktigt att vattenburna pelletssystem utformas korrekt och kombineras på rätt sätt med solvärme för att komforten ska bli hög och elanvändningen låg. Vattenmantlade pelletskaminer med ett vattenburet värmesystem är extra intressant i kombination med solvärme. När eldningen upphör i samband med att värmebehovet avtar kan solvärmen ta över. En generell slutsats är att konventionella svenska pelletspannor med inbyggd varmvattenberedning inte är lämpliga i kombination med solvärmesystem. Den typen av bränslepannor ger komplicerade systemlösningar, höga värmeförluster och det är svårt att åstadkomma en tillräckligt bra temperaturskiktning i ackumulatortanken om varmvattenberedning sker i pannan. Solvärme för varmvattenberedning kan vara ett enkelt och bra komplement till pelletskaminer som genererar varmluft. För solvärmesystem är det viktigt att kraftig temperaturskiktning erhålls när värmelagret laddas ur. Det betyder att ackumulatortankens (eller varmvattenberedarens) nedre vattenvolym ska kylas ner till temperaturer som ligger nära ingående kallvattentemperatur. Ackumulatortankens mellersta del bör kylas till samma temperatur som radiatorreturen. Vid design av solfångarkretsen måste överhettning och stagnation kunna klaras utan risk för glykolnedbrytning eller andra skador på värmebärare eller rörkrets (och andra komponenter i kretsen). Partiell förångning minskar risken för att glykolen skadas då solfångaren når höga stagnationstemperaturer. Solfångarens glykolblandning tillåts koka (förångas) på ett kontrollerat sätt så att endast ånga blir kvar i solfångaren. Vätskevolymen i solfångaren samlas upp i ett större expansionskärl och systemet återfylls när vätskan kondenserar. Dränerande solfångarsystem med enbart vatten är ett möjligt alternativ till konventionella solfångare. De kräver en större noggrannhet vid installationen, så att sönderfrysning undviks. Dränerande systemlösningar är relativt ovanliga i Sverige. Om solfångaren under senhöst-vinter-tidig vår kan arbeta med att förvärma kallvatten från 10 till 20 ºC erhålls en betydligt bättre verkningsgrad på solfångaren (och framför allt ökar värmeutbytet då drifttimmarna ökar väsentligt) än om radiatorreturen (som i bästa fall ligger på temperaturnivån 30 - 40 ºC) ska förvärmas. Därför bör radiatorreturen placeras en bra bit upp från botten i ackumulatortanken och tappvarmvattnet ska förvärmas i en slinga som börjar i tankens botten. Om det finns ett VVC-system måste systemet anslutas på ett speciellt sätt så att ackumulatortankens temperaturskiktning inte störs. En viktig parameter vid ackumulatortankens utformning är att värmeförlusterna hålls låga. Det är viktigt för att klara tappvarmvattenlasten med solvärme under mulna perioder sommartid (men också för att hålla energianvändningen låg). I moderna hus, där ackumulatortanken i regel placeras i bostaden, blir det en komfortfråga att undvika övertemperaturer i det rum där värmelagret placeras. En bra standard på isoleringen (med minimerade värmeförluster) kräver att det finns ett lufttätt skikt över hela isoleringen som dessutom sluter tätt mot röranslutningar. Ofrivillig självcirkulation i anslutande kretsar som kan kyla av och blanda om ackumulatortankens vattenvolym, bör förhindras med backventiler och nedböjning av rören i isolerskiktet eller direkt utanför tanken.

  • 2.
    Bales, Chris
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    External DHW Units for Solar Combisystems2003In: Solar Energy, Vol. 74, p. 193-204Article in journal (Refereed)
    Abstract [en]

    This article compares seven different external DHW units, comprising flat plate heat exchanger and flow control, with a reference method for preparing hot water. These DHW units use different control methods. The objective of the study was to determine which methods are most effective in solar combisystems and to identify other factors that strongly influence the energy savings of the system. Five of the DHW units were judged to be of interest for the study because of their measured performance or the simplicity of their design. Of these, measurement data showed that two had the same control function although of different physical construction. Thus four DHW units were modelled in the simulation environment PRESIM/ TRNSYS, parameters were identified from measured data, and annual simulations were performed with a number of parametric variations. Three of the DHW units performed significantly better than the reference system provided that they were sized correctly: microprocessor control with variable-speed pump; proportional controller with regulating valve; and a turbine pump. The most important design factors identified by the study were: the maximum possible primary flow, which needs to be suitable for the design hot water load profile; and ensuring a low temperature is returned to the store. The hot water load profile was also shown to strongly influence the energy savings, assuming that auxiliary heater’s thermostat is set so that the system just meets the worst-case discharge.

  • 3.
    Berg, Per E O
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Henning, Annette
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Lorenz, Klaus
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Nordlander, Svante
    Nygren, Ingemar
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Perman, Karin
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Förutsättningarna för en omställning från el till Pellets och Sol: Årsrapportering 2001 till Formas och STEM2001Report (Other academic)
  • 4. Cheeze, David
    et al.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Haller, Y. Michel
    Hamp, Quirin
    Matuska, Tomas
    Sourek, Borivoj
    Mojic, Igor
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Poppi, Stefano
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Report on prototype system’s energetic  performance and financial competitiveness - Deliverable 8.3 : MacSheep - New Materials and Control for a next generation of compact combined Solar and heat pump systems with boosted energetic and exergetic performance2016Report (Other (popular science, discussion, etc.))
  • 5. Chèze, David
    et al.
    Papillon, Philippe
    Leconte, Antoine
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Haller, Michel Y.
    Haberl, Robert
    Towards an harmonized whole system test method for combined renewable heating systems for houses2014Conference paper (Other academic)
    Abstract [en]

    The objective of this work is the development of harmonized efficiency test methods for combined renewable heating systems for houses, using a hardware-in-the-loop approach. An overview of the principles of the existing whole system test methods used by 3 research institutes involved in the project (MacSheep 2012) is given. Main objectives are realistic dynamic test sequence elaboration for solar and heat pump systems and comparison of results from tests achieved in different institutes. In order to reach these objectives, the first phase of the work aimed to harmonize the boundary conditions that comprise both the physical boundaries of the tested system as well as the climate and heat load definition, and this is presented in the first part of the article. The second part presents two methodologies to elaborate 12-days and 6-days whole system test sequences, validation results for solar and air source heat pump systems (SHP) and a methodology for achieving equal amount of space heat supplied by the tested system while at the same time providing a realistic response of the heat distribution system.

  • 6.
    Dalenbäck, Jan-Olov
    et al.
    Svensk Solenergi.
    Ollas, Patrik
    SP Energiteknik.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Biobränsle och solvärme för 100% förnybar värmeförsörjning: Projekt nr 30688-2 - Biobränsle och solvärme2015Report (Other academic)
  • 7. Dalenbäck, Jan-Olov
    et al.
    Pettersson, Ulrik
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Wood pellet and solar heating system development in Sweden. Initial result from system bench-marking test developments2011In: ESTEC 2011 -5th European Solar Thermal Energy Conference, Marseille, France, 2011Conference paper (Other academic)
    Abstract [en]

    Svensk Solenergi (Solar Energy Ass. of Sweden) and PellSam (Swedish Pellet Equipment Manufacturers Ass.) have joined forces to develop combined wood pellet and solar heating systems for the Nordic conditions. The cooperation has three main elements. A co-ordinated development project related to systems for single family houses (with co-financing from the Swedish Energy Agency), a common marketing campaign called “100%” (renewable heat) and certification of installers. The paper will focus on the development project. The development project comprises the development of a system design handbook and a combined system bench-marking and test method development. The test method (based on the Combitest method), is called Direct Characterization (DC) and the result is supposed to describe the annual system performance. It comprises laboratory measurements during 6 days on a whole system including (real) pellet boiler (or furnace), storage tank, controls and (simulated) solar collectors and load (based on selected weather data). The present set-up is for a typical single family building with 13 MWh space heating and 3 MWh DHW load. The test development has comprised a test of a reference boiler and 6 sample systems. Although all tested systems required less pellets than the reference boiler for the given load, only a few of the system designs take all aspects given in the handbook into account. The performance of the different systems varied a lot, from low 19 to high 37% less pellets than the reference boiler. The system tests have been carried out in two laboratories and one system has been tested in both laboratories with a reasonable agreement regarding the main parameters. The overall conclusion is that the test method seems to be possible to develop into a useful bench-mark method and that there are large possibilities for basic system improvements. Most of the tested systems consist of standard components combined into a system with a common control. Major system improvements are thus related to smaller boilers (furnaces) matched with improved and better insulated storage tanks (allowing reduced collector area) and better system controls (e.g. allowing less start and stop of the boiler/furnace). It is thus the intention to carry out a second round of system tests to include improved systems.

  • 8.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Optimisation method for solar heating systems in combination with pellet boilers/stoves2007In: International Journal of Green Energy, ISSN 1543-5075, E-ISSN 1543-5083, Vol. 4, no 3, p. 325-337Article in journal (Refereed)
    Abstract [en]

    In this study an optimisation method for the design of combined solar and pellet heating systems is presented and evaluated. The paper describes the steps of the method by applying it for an example system. The objective of the optimisation was to find the design parameters that give the lowest auxiliary energy (pellet fuel + auxiliary electricity) and carbon monoxide (CO) emissions for a system with a typical load, a single family house in Sweden. Weighting factors have been used for the auxiliary energy use and CO emissions to give a combined objective function. Different weighting factors were tested. The results show that extreme weighting factors lead to their own minima. However, it was possible to find factors that ensure low values for both auxiliary energy and CO emissions, and suitable weighting factors are suggested.

  • 9.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Nordlander, Svante
    Comparison of carbon monoxide emissions and electricity consumption of modulating and non-modulating pellet and solar heating systems2007In: International journal of energy research (Print), ISSN 0363-907X, E-ISSN 1099-114X, Vol. 31, no 10, p. 915-930Article in journal (Refereed)
    Abstract [en]

    Emission and electricity consumption are important aspects of a pellet heating system. Low noxious emissions, particularly carbon monoxide, are a measure of a well-performing system. High carbon monoxide emissions are often caused by unnecessary cycling of the burner, poor adjustment of the combustion air and insufficient maintenance. The carbon monoxide output, the thermal performance and the electricity consumption for modulating and non-modulating operation mode have been investigated by simulations of four stoves/boilers as part of combined solar and pellet heating systems. The systems have been modelled with the simulation programme TRNSYS and simulated with the boundary conditions for space heating demand, hot water load and climate data as used in earlier research projects. The results from the simulations show that operating the pellet units with modulating combustion power reduces the number of starts and stops but does not necessarily reduce the carbon monoxide output. Whether the carbon monoxide output can be reduced or not depends very strongly on the reduction of starts and stops and how much the carbon monoxide emissions increase with decreased combustion power, which are in turn dependent on the particular settings of each pellet burner and how the heat is transferred to the building. However, for most systems the modulating operation mode has a positive impact on carbon monoxide emissions. Considering the total auxiliary energy demand, including the electricity demand of the pellet units, the modulating combustion control is advantageous for systems 1 and 4 for the used boundary conditions. The study also shows that an appropriate sizing of the stove or boiler has a huge potential for energy saving and carbon monoxide emission reduction.

  • 10.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Thür, Alexander
    Design method for solar heating systems in combination with pellet boilers/stoves2006In: EuroSun 2006, Glasgow, UK, 2006Conference paper (Other academic)
    Abstract [en]

    In this study an optimization method for the design of combined solar and pellet heating systems is presented and evaluated. The paper describes the steps of the method by applying it for an example of system. The objective of the optimization was to find the design parameters that give the lowest auxiliary energy (pellet fuel + auxiliary electricity) and carbon monoxide (CO) emissions for a system with a typical load, a single family house in Sweden. Weighting factors have been used for the auxiliary energy use and CO emissions to give a combined target function. Different weighting factors were tested. The results show that extreme weighting factors lead to their own minima. However, it was possible to find factors that ensure low values for both auxiliary energy and CO emissions.

  • 11.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Nordlander, Svante
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Thermal performance of combined solar and pellet heating systems2006In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 31, no 1, p. 73-88Article in journal (Refereed)
    Abstract [en]

    Various pellet heating systems are marketed in Sweden, some of them in combination with a solar heating system. Several types of pellet heating units are available and can be used for a combined system. This article compares four typical combined solar and pellet heating systems: System 1 and 2 with a pellet stove, system 3 with a store integrated pellet burner and system 4 with a pellet boiler. The often lower efficiency of pellet heaters compared to oil or gas heaters increases the final energy demand. Consequently heat losses of the various systems have been studied. The systems have been modeled in TRNSYS and simulated with parameters identified from measurements. For almost all systems the flue gas losses are the main heat losses except for system 3 where store heat losses prevail. Relevant are also the heat losses of the burner and the boiler to the ambient. Significant leakage losses are noticed for system 3 and 4. For buildings with an open internal design system 1 is the most efficient solution. Other buildings should preferably apply system 2 or 3. The right choice of the system depends also on whether the heater is placed inside or outside of the heated area. Unlike the expectations and results from other studies, the operation of the pellet heaters with modulating combustion power is not necessarily improving the performance. A large potential for system optimization exists for all studied systems, which when applied could alter the relative merits of the different system types.

  • 12.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Annual CO-emissions of combined pellet and solar heating systems2007In: ISES Solar World Congress 2007, ISES 2007, 2007, Vol. 4, p. 2468-2472Conference paper (Other academic)
    Abstract [en]

    Emissions are an important aspect of a pellet heating system. High carbon monoxide emissions are often caused by unnecessary cycling of the burner when the burner is operated below the lowest combustion power. Combining pellet heating systems with a solar heating system can significantly reduce cycling of the pellet heater and avoid the inefficient summer operation of the pellet heater. The aim of this paper was to study CO-emissions of the different types of systems and to compare the yearly CO-emissions obtained from simulations with the yearly CO-emissions calculated based on the values that are obtained by the standard test methods. The results showed that the yearly CO-emissions obtained from the simulations are significant higher than the yearly CO-emissions calculated based on the standard test methods. It is also shown that for the studied systems the average emissions under these realistic annual conditions were greater than the limit values of two Eco-labels. Furthermore it could be seen that is possible to almost halve the CO-emission if the pellet heater is combined with a solar heating system.

  • 13.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Carbon monoxide emissions of combined pellet and solar heating systems2007In: International Green Energy Conference III, Västerås, 2007Conference paper (Other academic)
  • 14.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Carbon monoxide emissions of combined pellet and solar heating systems2009In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 86, no 2, p. 135-143Article in journal (Refereed)
    Abstract [en]

    Emissions are an important aspect of a pellet heating system. Low harmful emissions, particularly carbon monoxide, are a measure of a well performing system. High carbon monoxide emissions are often caused by unnecessary cycling of the burner and when the average load is below the lowest possible combustion power of the burner. Combining pellet heaters with a solar heating system can significantly reduce cycling of the pellet heater and avoid the inefficient summer operation of the pellet heater. Five combined systems representing the range of typical solutions of this system type and one recently developed system have been studied, modelled and simulated. These systems are compared to a reference system, which is based on a pellet boiler and is not combined with a solar heating system. The aim was to study CO-emissions of the different types of systems and to analyse the potential of CO-emission reduction when the pellet heater is combined with a solar heating systems. Another aim was to compare the yearly CO-emissions obtained from simulations under realistic dynamic conditions with the yearly CO-emissions calculated based on the values that are obtained by the standard test methods. The study was performed with the simulation tool TRNSYS. The parameter used in the study have been identified from lab measurements on existing pellet boilers/stoves and solar heating systems. The results from the simulations show that it is possible to almost halve the CO-emission if the pellet heater is combined with a solar heating system. The results also show that the CO-emission of existing combined solar and pellet heating systems can be drastically reduced if the pellet heater is properly controlled and some basic design rules are observed. This can also be seen when analyzing the results for the new system concept where these rules have been taken into account. Comparing the yearly CO-emissions obtained from the simulations with the yearly CO-emissions calculated based on the standard test methods shows that using the latter give too low CO-values for the whole year. It is also shown that for the existing systems the average emissions under these realistic annual conditions were greater than the limit values of two Eco-labels.

  • 15.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    CO-Emissionen solarer Kombisysteme mit Holzpelletkesseln2008In: 18. Symposium Thermische Solarenergie, Kloster Banz, Bad Staffelstein, 2008Conference paper (Other academic)
  • 16.
    Fiedler, Frank
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Reduction of co-emissions by combining pellet and solar heating systems2008In: Eurosun 2008, Lisbon, 2008Conference paper (Other academic)
    Abstract [en]

    Emissions are an important aspect of a pellet heating system. High carbon monoxide emissions are often caused by unnecessary cycling of the burner when the burner is operated below the lowest combustion power. Combining pellet heating systems with a solar heating system can significantly reduce cycling of the pellet heater and avoid the inefficient summer operation of the pellet heater. The aim of this paper was to study CO-emissions of the different types of systems and to compare the yearly CO-emissions obtained from simulations with the yearly CO-emissions calculated based on the values that are obtained by the standard test methods. The results showed that the yearly CO-emissions obtained from the simulations are significant higher than the yearly CO-emissions calculated based on the standard test methods. It is also shown that for the studied systems the average emissions under these realistic annual conditions were greater than the limit values of two Eco-labels. Furthermore it could be seen that is possible to almost halve the CO-emission if the pellet heater is combined with a solar heating system.

  • 17. Fiedler, Frank
    et al.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Nordlander, Svante
    Heat losses and thermal performance of commercial combined solar and pellet heating systems2004In: Eurosun 2004, Freiburg/Germany, 2004Conference paper (Other academic)
    Abstract [un]

    Various pellet heating systems are marketed in Sweden, some of them in combination with a solar heating system. Several types of pellet heating units are available and can be used for a combined system. This article compares four typical combined solar and pellet heating systems: System 1 and 2 two with a pellet stove, system 3 with a store integrated pellet burner and system 4 with a pellet boiler. The lower efficiency of pellet heaters compared to oil or gas heaters increases the primary energy demand. Consequently heat losses of the various systems have been studied. The systems have been modeled in TRNSYS and simulated with parameters identified from measurements. For almost all systems the flue gas losses are the main heat losses except for system 3 where store heat losses prevail. Relevant are also the heat losses of the burner and the boiler to the ambient. Significant leakage losses are noticed for system 3 and 4. For buildings with an open internal design system 1 is the most efficient solution. Other buildings should preferably apply system 3. The right choice of the system depends also on whether the heater is placed inside or outside of the heated are. A large potential for system optimization exist for all studied systems, which when applied could alter the relative merits of the different system types.

  • 18.
    Haberl, Robert
    et al.
    Institute for Solar Technology SPF, HSR University of Applied Sciences, Switzerland.
    Haller, Michell Y.
    Institute for Solar Technology SPF, HSR University of Applied Sciences, Switzerland.
    Papillon, Philippe
    CEA INES, France.
    Chèze,, David
    CEA INES, France.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Testing of combined heating systems for small houses: Improved procedures for whole system test methods: Deliverable 2.32015Report (Other academic)
    Abstract [en]

    Dynamic system test methods for heating systems were developed and applied by the institutes SERC and SP from Sweden, INES from France and SPF from Switzerland already before the MacSheep project started. These test methods followed the same principle: a complete heating system – including heat generators, storage, control etc., is installed on the test rig; the test rig software and hardware simulates and emulates the heat load for space heating and domestic hot water of a single family house, while the unit under test has to act autonomously to cover the heat demand during a representative test cycle. Within the work package 2 of the MacSheep project these similar – but different – test methods were harmonized and improved. The work undertaken includes: 

    • Harmonization of the physical boundaries of the unit under test.

    • Harmonization of the boundary conditions of climate and load.

    • Definition of an approach to reach identical space heat load in combination with an autonomous control of the space heat distribution by the unit under test.

    • Derivation and validation of new six day and a twelve day test profiles for direct extrapolation of test results.

     

    The new harmonized test method combines the advantages of the different methods that existed before the MacSheep project. The new method is a benchmark test, which means that the load for space heating and domestic hot water preparation will be identical for all tested systems, and that the result is representative for the performance of the system over a whole year. Thus, no modelling and simulation of the tested system is needed in order to obtain the benchmark results for a yearly cycle. The method is thus also applicable to products for which simulation models are not available yet.

    Some of the advantages of the new whole system test method and performance rating compared to the testing and energy rating of single components are: 

    • Interaction between the different components of a heating system, e.g. storage, solar collector circuit, heat pump, control, etc. are included and evaluated in this test.

    • Dynamic effects are included and influence the result just as they influence the annual performance in the field.

    • Heat losses are influencing the results in a more realistic way, since they are evaluated under "real installed" and representative part-load conditions rather than under single component steady state conditions.

     

    The described method is also suited for the development process of new systems, where it replaces time-consuming and costly field testing with the advantage of a higher accuracy of the measured data (compared to the typically used measurement equipment in field tests) and identical, thus comparable boundary conditions. Thus, the method can be used for system optimization in the test bench under realistic operative conditions, i.e. under relevant operating environment in the lab.

     

    This report describes the physical boundaries of the tested systems, as well as the test procedures and the requirements for both the unit under test and the test facility. The new six day and twelve day test profiles are also described as are the validation results.

  • 19.
    Haller, Michel Yves
    et al.
    SPF Institut für Solartechnik, Hochschule für Technik.
    Haberl, Robert
    SPF Institut für Solartechnik, Hochschule für Technik.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Kovacs, Peter
    Technical Research Institutue of Sweden.
    Chèze, David
    CEA, INES.
    Papillon, Philippe
    CEA, INES.
    Dynamic whole system testing of combined renewable heating systems: the current state of the art2013In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 66, p. 667-677Article in journal (Refereed)
    Abstract [en]

    Objective: For the evaluation of the energetic performance of combined renewable heating systems that supply space heat and domestic hot water for single family houses, dynamic behaviour, component interactions, and control of the system play a crucial role and should be included in test methods.

    Methods: New dynamic whole system test methods were developed based on “hardware in the loop” concepts. Three similar approaches are described and their differences are discussed. The methods were applied for testing solar thermal systems in combination with fossil fuel boilers (heating oil and natural gas), biomass boilers, and/or heat pumps.

    Results: All three methods were able to show the performance of combined heating systems under transient operating conditions. The methods often detected unexpected behaviour of the tested system that cannot be detected based on steady state performance tests that are usually applied to single components.

    Conclusion: Further work will be needed to harmonize the different test methods in order to reach comparable results between the different laboratories.

    Practice implications: A harmonized approach for whole system tests may lead to new test standards and improve the accuracy of performance prediction as well as reduce the need for field tests.

  • 20.
    Heier, Johan
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Ekonomisk utvärdering av olika uppvärmningsalternativ2010In: Klimatsmart villavärme? Solvärme, nya byggregler och möjligheten att förändra / [ed] Henning, Annette, Falun: Författarna och SERC , 2010, p. 93-106Chapter in book (Other academic)
    Abstract [sv]

    En ekonomisk utvärdering har genomförts baserad på första årets energi-, kapital- och under-hållskostnader. Kapitalkostnader delas upp på komponentens förväntade livslängd med annui-tetsmetoden. Framtida underhållskostnader diskonteras till ett nuvärde och delas upp med annuitetsmetoden. Dagens energipriser och en kalkylränta på 4,5 % används som utgångspunkt, men varieras för olika scenarier. Fjärrvärme tycks ge bland de lägsta kostnaderna av de studerade alternativen. I alla fall i de kommuner som ligger under medelpriset för svensk fjärrvärme. Vedeldning har inte studerats här, men ger säkerligen lägst totalkostnader om man accepterar den tid som krävs för att hantera ved och elda. Det studerade passivhuset hör också till de alternativ som har bland de lägsta kostnaderna då investering och energianvändning vägs samman. Men räntenivån har en stor inverkan på systemens totalkostnad. Låg ränta har en utjämnande effekt på totalkostnaden. Vid högre ränta ökar kostnaden mest för system med lång livslängd (avskrivningstid), vilket gör passivhusen dyrare. Pelleteldning i nybyggda hus kommer nog att utgöra en mindre del av installationerna, då det krävs FTX och investeringskostnaden blir ganska hög, men om lösningar med frånluftvärmepump och luftburen pelletkamin mot förmodan skulle komma att uppfylla kraven för ett icke elvärmt hus kan det bli ett uppsving av sådana lösningar.

  • 21.
    Hägerby, Daniel
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Vägar och irrvägar till energieffektivisering: vägvalet är politiskt2012Report (Other (popular science, discussion, etc.))
    Abstract [sv]

    Rapporten är en litteraturstudie som lyfter vikten av ett systemperspektiv på energianvändningen och diskuterar samhällets mål och medel utifrån detta perspektiv. För att väga in de olika effekter som en förändrad energianvändning innebär måste olika bedömningar göras. Vi konstaterar att det finns stora osäkerheter i detta, men att det viktigaste inte är att finna en exakt värdering av de olika energikällorna. Istället bör fokus ligga på att, ur ett systemperspektiv, fastställa och implementera en värdering av de olika energikällorna samt låta denna värdering vara konsekvent tvärs över alla sektorer. Det viktiga är alltså inte den exakta fördelningen mellan kol- och gas på marginalen i Danmark och Tyskland i framtiden, utan att vi överhuvudtaget antar ett systemperspektiv och ser till hur förändringar i vår konsumtion påverkar energisystemet som helhet. EU har valt att fokusera på primärenergi när det gäller mål för energieffektivisering, eftersom man inte vill reducera den nytta som energianvändningen skapar i användarledet, utan snarare vill minska slöseriet på väg till slutanvändning. Vi har i Sverige valt liknande mål för energieffektivisering, men ännu inte lyckats implementera några styrmedel som genomsyras av ett system- eller primärenergiperspektiv. Vi har i båda de exempel som vi tar upp lyckats identifiera spår av systemtänkande, som dock inte lyckats nå hela vägen. Det första är att Boverket ser ut att ha utgått från ett systemperspektiv vid utformningen av det ursprungliga förslaget till byggregler 2006, med en tydlig linje inom värme och kyla för både lokaler och bostäder. Det andra är i trafikskattelagstiftningen där även utsläpp uppströms från avgasröret räknats med, fast inte värderats på något enhetligt sätt. Det är viktigt att styrmedlen inte utformas så att det styr "ur askan i elden". Beroende på hur vi värderar t.ex. den el som används för att ladda elfordon finns här en uppenbar sådan risk. Oavsett befintliga styrmedel pekar rapporten på det utrymme för diskussion som finns kring värdering av olika energikällors resursavtryck samt svårigheterna i att vetenskapligt bestämma den exakt korrekta viktningsfaktorn för varje energikälla. Dock finns det gränser för vad som, på en för de flesta investeringar relevant horisont, kan anses rimligt. Inom dessa gränser är det upp till politiken att, genom styrmedlens utformning, definiera de relativa viktningar som marknaden sedan får förhålla sig till. Här ligger EU längre fram än Sverige, trots att svårigheterna att komma överens rimligen borde vara större i europaparlamentet än i svenska riksdagen. Samtidigt som det är viktigt att sträva efter styrmedel som ger önskad effekt får dessa förstås inte ändras för ofta, eftersom det leder till osäkerhet och uteblivna investeringar. När det gäller energipolitiken är dock riktlinjerna från EU tydliga och frågan är när Sverige ansluter sig till det primärenergiperspektiv som EU förespråkar, även vid utformningen av svenska energipolitiska styrmedel. Det är också viktigt att energianvändning i alla sektorer behandlas på ett likartat sätt. För att hantera detta kan det vara klokt att hänvisa till en gemensam standard eller ett gemensamt direktiv från Energimyndigheten och/eller Naturvårdsverket som definierar olika energikällors primärenergifaktor, liknande hur Tyskland gjort med sina byggregler.

  • 22. Lennermo, Gunnar
    et al.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Perers, Bengt
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Pettersson, Ulrik
    Johansson, Mathias
    Underlag för utökad besiktning av bio- och solvärmesystem: Formulär med analyshjälp2011Report (Other academic)
    Abstract [sv]

    Det är svårt att på ett genomarbetat sätt, kontrollera en solvärmeanläggning som är i drift och det blir svårare när solvärmesystemet skall samverka med en biobränsleanläggning, som har sina speciella egenheter. Det enklaste och, som det kan tyckas, bästa sättet att kontrollera om en solvärmeanläggning fungerar, är att beräkna utifrån en värmemängdsmätare, som förhoppningsvis finns i anläggningen, hur mycket energi per m2 aktiv area som solfångaren har producerat per år. Om produktionen ligger mellan 300 – 350 kWh/m2 så är det bra. Det är dock så att en solvärmeanläggning borde kunna producera betydligt mer värme om den bara ges lite bättre förutsättning eller att den faktiskt kan ge mindre, men ändå uppfylla de krav som ställdes. Det behöver inte nödvändigtvis vara antalet producerade solfångar-kWh värme som är högt utan det viktigaste kanske är att antalet inbesparade kWh biobränsle är många. För att kunna få ett grepp om hur en solvärmeanläggning fungerar i sitt sammanhang så bör det totala systemet redovisas framför allt med avseende på: -Värmedistributionssystemets uppbyggnad. Var och när finns kallt vatten som ska värmas samt hur mycket. -Energi- och effektnivåer för olika delar av systemet och fram för allt under sommaren -Vilka pannor och bränslen som används, framför allt med betoning på reglerbarhet Solvärmekretsen, som inte är speciellt annorlunda utformad än i andra lite större solvärmeanläggningar ges i den här rapporten relativt stort utrymme, eftersom den samlade kompetensen bland de som gör besiktningar och kontroller inte är så hög. De delar som berörs mest är: -Trycket i solvärmeanläggningen med avseende på expansionskärlets förtryck, systemets uppfyllnadstryck och driftsfunktioner -Flödet i anläggningen som inriktar sig på luftmedryckning, flödesfördelning och vanliga flödeshastigheter -Solfångarnas energi- och värmeeffektproduktion Huvuddelen av underlagsmaterialet bör ha samlats in före besöket, genom att försöka få tag på: -Förstudier för solvärme- och pannanläggning -Förfrågningsunderlag för i första hand solvärmeanläggningen -Driftstatistik -Data på hur det totala systemet ser ut. Dessa data bör bearbetas innan besöket på plats vilket skall inkludera en genomgång av driftsansvarig vilket kompletteras med en guidad tur genom anläggningen. Besöket bör också vara förberett hos driftsansvariga så att stegar för att komma åt solfångarna finns framtagna och de säkerhetsselar som skall finnas vid okulär inspektion finns tillgängliga. Efter avslutad på platsen kontroll ska en besiktningsrapport skrivas. Mycket underlagsberäkningar ska skickas med som bilaga samt en lista med punkter som syftar till att få en effektivare sol- och biobränsleanläggning.

  • 23. Lennermo, Gunnar
    et al.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Perers, Bengt
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Pettersson, Ulrik
    Johansson, Mathias
    Underlag för utökad besiktning av sol- och biovärmesystem2011Report (Other academic)
    Abstract [sv]

    Det är svårt att på ett genomarbetat sätt, kontrollera en solvärmeanläggning som är i drift och det blir svårare när solvärmesystemet ska samverka med en biobränsleanläggning, som har sina speciella egenheter. Det enklaste och, som det kan tyckas, bästa sättet att kontrollera om en solvärmeanläggning fungerar, är att beräkna utifrån en värmemängdsmätare, som förhoppningsvis finns i anläggningen, hur mycket energi per m2 aktiv area som solfångaren har producerat per år. Om produktionen ligger mellan 300 – 350 kWh/m2 är det bra. Det är dock så att en solvärmeanläggning borde kunna producera betydligt mer värme om den bara ges lite bättre förutsättning eller att den faktiskt kan ge mindre, men ändå uppfylla de krav som ställdes. Det behöver inte nödvändigtvis vara antalet producerade solfångarkWh värme som är högt utan det viktigaste kanske är att antalet inbesparade kWh biobränsle är många. För att kunna få ett grepp om hur en solvärmeanläggning fungerar i sitt sammanhang bör det totala systemet redovisas framför allt med avseende på: • Värmedistributionssystemets uppbyggnad. Var, när och hur mycket kallt vatten ska värmas? • Energi- och effektnivåer för olika delar av systemet, framför allt under sommaren? • Vilka pannor och bränslen används, framför allt med betoning på reglerbarhet? Solvärmekretsen, som inte är speciellt annorlunda utformad än i andra lite större solvärmeanläggningar, ges i den här rapporten relativt stort utrymme, eftersom den samlade kompetensen bland de som gör besiktningar och kontroller inte är så hög. Mest berörda delar är: • Trycket i solvärmeanläggningen med avseende på expansionskärlets förtryck, systemets uppfyllnadstryck och driftsfunktioner • Flödet i anläggningen som inriktar sig på luftmedryckning, flödesfördelning och vanliga flödeshastigheter • Solfångarnas energi- och värmeeffektproduktion Huvuddelen av underlagsmaterialet bör ha samlats in före besöket, genom att försöka få tag på: • Förstudier för solvärme- och pannanläggning • Förfrågningsunderlag för i första hand solvärmeanläggningen • Driftstatistik • Data på hur det totala systemet ser ut Dessa data bör bearbetas innan besöket på plats, vilket ska inkludera en genomgång av driftsansvarig kompletterat med en guidad tur genom anläggningen. Besöket bör också vara förberett hos driftsansvariga så att stegar för att komma åt solfångarna finns framtagna och de säkerhetsselar, som ska användas vid okulär inspektion, finns tillgängliga. Efter avslutad på-platsen-kontroll ska en besiktningsrapport skrivas. Mycket underlagsberäkningar ska skickas med som bilaga samt en lista med punkter som syftar till att få en effektivare sol- och biobränsleanläggning.

  • 24.
    Lorenz, Klaus
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Evaluation of Solar Thermal Combisystems for the Swedish Climate2000In: Eurosun 2000, Copenhagen, 2000Conference paper (Other academic)
    Abstract [en]

    This paper summarises the results of previous work in the area and then goes on to describe the results of a more detailed simulation study of a number of different system designs. For these systems, the boundary conditions were: modern Swedish single family house in Stockholm (255 MJ/m2.year heating load); moderate DHW load (11.3 GJ/year); and typical Swedish single glazed collector with selective surface absorber. For the majority of the parametric studies, these boundary conditions were kept constant, but a section of the paper describes the influence of these boundary conditions on the system performance. All system designs and their variations are compared to a reference solar combisystem, the most common combisystem type in Sweden. The simulation work is based on models that have been validated against detailed measurements on several stores and components. The results show that the fractional energy savings can be increased by over 30% from the reference combisystem, given the same system size, collector type and load size. The two major improvements in performance are achieved by using an external DHW unit instead of the two heat exchangers in the store, and by having a low return temperature from the heating circuit. Several other variations are shown to have lesser influence on the energy savings.

  • 25.
    Lorenz, Klaus
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Tepe, Rainer
    Variation of System Performance with Design and Climate for Combisystems in Sweden1998In: Eurosun -98, Portoroz, Slovenia, 1998Conference paper (Other academic)
    Abstract [en]

    In Sweden, 90% of the solar heating systems are solar domestic hot water and heating systems (SDHW&H), so called combisystems. These generally supply most of the domestic hot water needs during the summer and have enough capacity to supply some energy to the heating system during spring and autumn. This paper describes a standard Swedish combisystem and how the output from it varies with heating load, climate within Sweden, and how it can be increased with improved system design. A base case is defined using the standard combi- system, a modern Swedish single family house and the climate of Stockholm. Using the simulation program Trnsys, parametric studies have been performed on the base case and improved system designs. The solar fraction could be increased from 17.1% for the base case to 22.6% for the best system design, given the same system size, collector type and load. A short analysis of the costs of changed system design is given, showing that payback times for additional investment are from 5-8 years. Measurements on system components in the laboratory have been used to verify the simulation models used. More work is being carried out in order to find even better system designs, and further improvements in system performance are expected.

  • 26.
    Lorenz, Klaus
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Comparison of External DHW Load Side Heat Exchange Units for Small Solar Storage Systems1997In: North Sun ´97 / [ed] Konttinen, P.; Lund, P. D., Espoo-Otaniemi, Finland, 1997Conference paper (Other academic)
    Abstract [en]

    This paper compares the performance of four load side heat exchange units that could be used with storage tanks in solar heating systems to make domestic hot water (DHW). The unit consists of a flat plate heat exchanger and a controller that regulates the primary (tank side) flow in a predetermined way. Several tests were carried out in order to determine the static and dynamic performance of the units. The two best units were connected in turn to a standard solar heating system and the thermal performance of the whole system was measured using a six-day test sequence. In addition simulation models of these two units were constructed and their parameters identified. The results show that not all of the units are suitable for use in solar heating systems. Two completely different control strategies achieve reasonable thermal performance. When used in a standard high flow Swedish solar system instead of the usual internal load side heat exchangers, the solar fraction of the whole system is improved by over 10%.

  • 27.
    Lorenz, Klaus
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Tepe, Rainer
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Förstude: Beskrivning av uppvärmningssystem med solfångare och värmepump för området Anneberg i Danderyds Kommun1999Report (Other academic)
    Abstract [sv]

    Anneberg är ett område i Danderyds kommun där det skall beredas plats för ett nytt bostadsområde. Området skall bebyggas med flerbostadshus, gruppbostäder och ett sjukhem. Denna förstudie beskriver översiktligt 3 systemförslag som kan användas för uppvärmning av husen i bostadsområdet Anneberg. Målsättningen är att presentera uppvärmningssystem som visar hur solenergi kan användas för att öka värmepumpsystemens värmefaktor. Systemen modellerades i TRNSYS och systemfunktionen samt energiflöden simulerades. Simulerade prestanda för tre olika typer av uppvärmningssystem redovisas. System A är ett vanligt värmepumpsystem med borrhål och värmepump placerad i ett flerfamiljshus av typ 3. System B liknar system A, men har kompletterats med en glasad solfångare för varmvattenberedning. System C är en lösning som kan tillämpas för större byggnader eller för ett område med flera byggnader. Systemet har ett gemensamt värmelager och ett kulvertsystem som förbinder byggnaderna med värmelagret. I varje ansluten byggnad installeras sedan en värmepump och en oglasad solfångare. Simuleringsresultatet redovisas som en värmefaktor för systemets fem första driftår. System A får en värmefaktor på mellan 2,3 och 2,7 för de första 5 driftåren. System B får en värmefaktor på mellan 3,4 och 3,7 och system C får en värmefaktor på mellan 4,0 och 4,5. Studien visar att det går att öka värmefaktorn på en värmepumpanläggning från ca 2,5 upp till 4 eller 4,5 genom att komplettera anläggningen med solfångare och värmelager. Detta innebär att elförbrukningen minskar från att vara ca 40 % av värmebehovet ned till under 25 % av värmebehovet. Det bör således finnas en potential för att komplettera värmepumpanläggningar med solvärme. Vilket utförande som kan bli ekonomiskt intressant kan inte bedömas i denna förstudie. I förstudien visas enbart resultatet för tre enstaka systemutföranden. Inga parametervariationer (tex solfångaryta, antal borrhål och avstånd mellan borrhålen) är utförda. En sådan systemoptimering bör göras med förstudien som utgångsläge.

  • 28. Menegon, D.
    et al.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Haberl, R.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Haller, M.
    Direct characterisation of the annual performance of solar thermal and heat pump systems using a six-day whole system test2020In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 146, p. 1337-1353Article in journal (Refereed)
  • 29.
    Niklasson, Fredrik
    et al.
    SP Energiteknik, Borås.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Marknadspotential för bio- och solvärmesystem2008Report (Other academic)
    Abstract [sv]

    I denna rapport analyseras marknaden för kombinerade sol- och pelletsystem, medfokus på småhus. Syftet är att presentera antalet objekt inom olika kategorier av husoch värmesystem som kan vara intressanta för konvertering till bio-sol system samtatt ge en uppskattning av årliga uppvärmningsbehov inom respektive kategori.

    Energistatistik från Statistiska centralbyrån (SCB) har använts i kombination medtidigare studier av byggnadsbestånd och byggnadsutformning. Dessutom harinformation inhämtats från olika branschorganisationer.

    Från föreliggande genomgång står det klart att den största potentialen för bio-solsystem finns på villamarknaden både för helt nya system och för kompletteringar tillbefintliga system. År 2006 fanns det 775 000 småhus med vattenburen värme varav ca183 000 hade vattenburen el. Uppskattningsvis fanns 109 000 småhus med bådevattenburen el och lokaleldstad för biobränsle och ca 118 000 hus bedöms ha haftmöjlighet till oljeeldning (denna grupp har troligtvis minskat ytterligare efter 2006).Bland de elvärmda husen finns också ca 102 000 småhus med frånluftvärmepumpareller luft/vattenvärmepumpar. 365 000 av husen hade en biobränslepanna. Därtillkommer 504 000 hus med direktelvärme, varav ca 292 000 med lokaleldstad.

    Medelförbrukningen för uppvärmning och varmvatten för hus som enbart värms medolja är ca 27 MWh/år, medan motsvarande värde för småhus med vattenburen el är ca15 MWh/år. Småhusen med direktel använder ca 12 MWh/år för uppvärmning ochvarmvatten. Det betyder att ekonomin blir betydligt sämre vid konvertering avelvärmda hus jämfört med oljekonvertering, eftersom energibehovet är lägre samt attinstallationskostnaden kan vara högre.

    En uppskattning av antalet komponenter som inom 10 år kan komma att installeras idessa hus är 213 000 solfångare, 108 000 ackumulatortankar, 106 000 skorstenar,84 000 luftburna pelletkaminer och varmvattenberedare, 40 000 vattenmantladekaminer och 28 000 pannrumspannor. Dessutom tillkommer en utbytesmarknad,kanske speciellt bland husen med biobränslepanna, där gamla pannor byts ut elleräldre människor som tidigare orkat elda med ved till slut byter till pelleteldning.

    Av nybyggda villor uppvärms ca 30 % med el i kombination med biobränsle(troligtvis lokaleldstad) och ungefär lika stor andel värms med enbart vattenburen el(antagligen ofta kompletterat med frånluftvärmepump). Det borde vara av intresse attredan vid nybyggnationen få in integrerade solfångare och pelleteldning i störreutsträckning i nya hus och det kan bli lättare efter att byggreglerna ändras den 1:ajanuari 2010 med en skärpning av kraven för nybyggda hus som använder el föruppvärmning, alltså även el till värmepumpar.

    Potentialen för bio-solsystem till flerbostadshus och lokaler är begränsad då 86 % avflerbostadshusen och nära 70 % av lokalerna värms med fjärrvärme. Det fanns år2006 ca 6200 lokaler med oljeeldning, 4600 lokaler med vattenburen elvärme och5700 lokaler med direktverkande elvärme. I lokalerna som redovisas av SCB ingårinte tillverkande industri. För lägenheter i flerbostadshus gäller att ca 42 000lägenheter värms med enbart olja, 44 000 lägenheter med olja och värmepump,48 000 lägenheter använder direktel och 31 000 lägenheter vattenburen el.

  • 30.
    Niklasson, Fredrik
    et al.
    SP Energiteknik, Borås.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Marknadspotential för sol- och biovärmesystem2010Report (Other academic)
    Abstract [sv]

    I denna rapport analyseras marknaden för kombinerade sol- och pelletsystem, med fokus påsmåhus. Syftet är att presentera antalet objekt inom olika kategorier av hus och värmesystemsom kan vara intressanta för konvertering till bio-sol system samt att ge en uppskattning avårliga uppvärmningsbehov inom respektive kategori.

    Energistatistik från Statistiska centralbyrån (SCB) har använts i kombination med tidigarestudier av byggnadsbestånd och byggnadsutformning. Dessutom har information inhämtatsfrån olika branschorganisationer.

    Från föreliggande genomgång står det klart att den största potentialen för bio-sol systemfinns på villamarknaden både för helt nya system och för kompletteringar till befintliga system.År 2006 fanns det 775 000 småhus med vattenburen värme varav ca 183 000 hade vattenburenel. Uppskattningsvis fanns 109 000 småhus med både vattenburen el och lokaleldstadför biobränsle och ca 118 000 hus bedöms ha haft möjlighet till oljeeldning (dennagrupp har troligtvis minskat ytterligare efter 2006). Bland de elvärmda husen finns också ca102 000 småhus med frånluftvärmepumpar eller luft/vattenvärmepumpar. 365 000 av husenhade en biobränslepanna. Därtill kommer 504 000 hus med direktelvärme, varav ca 292 000med lokaleldstad.

    Medelförbrukningen för uppvärmning och varmvatten för hus som enbart värms med olja ärca 27 MWh/år, medan motsvarande värde för småhus med vattenburen el är ca 15 MWh/år.Småhusen med direktel använder ca 12 MWh/år för uppvärmning och varmvatten. Det betyderatt ekonomin blir betydligt sämre vid konvertering av elvärmda hus jämfört med oljekonvertering,eftersom energibehovet är lägre samt att installationskostnaden kan vara högre.En uppskattning av antalet komponenter som inom 10 år kan komma att installeras i dessahus är 213 000 solfångare, 108 000 ackumulatortankar, 106 000 skorstenar, 84 000 luftburnapelletkaminer och varmvattenberedare, 40 000 vattenmantlade kaminer och 28 000 pannrumspannor.Dessutom tillkommer en utbytesmarknad, kanske speciellt bland husen medbiobränslepanna, där gamla pannor byts ut eller äldre människor som tidigare orkat elda medved till slut byter till pelleteldning.

    Av nybyggda villor uppvärms ca 30 % med el i kombination med biobränsle (troligtvis lokaleldstad)och ungefär lika stor andel värms med enbart vattenburen el (antagligen oftakompletterat med frånluftvärmepump). Det borde vara av intresse att redan vid nybyggnationenfå in integrerade solfångare och pelleteldning i större utsträckning i nya hus och det kanbli lättare efter att byggreglerna ändras den 1:a januari 2010 med en skärpning av kraven förnybyggda hus som använder el för uppvärmning, alltså även el till värmepumpar.

    Potentialen för bio-solsystem till flerbostadshus och lokaler är begränsad då 86 % av flerbostadshusenoch nära 70 % av lokalerna värms med fjärrvärme. Det fanns år 2006 ca 6200lokaler med oljeeldning, 4600 lokaler med vattenburen elvärme och 5700 lokaler med direktverkandeelvärme. I lokalerna som redovisas av SCB ingår inte tillverkande industri. Förlägenheter i flerbostadshus gäller att ca 42 000 lägenheter värms med enbart olja, 44 000lägenheter med olja och värmepump, 48 000 lägenheter använder direktel och 31 000 lägenhetervattenburen el.

  • 31.
    Nordlander, Svante
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Evaluation and computer modelling of wood pellet stoves with liquid heat exchangers2003In: presented at ISES Solar World Congress, Göteborg, Sweden, 2003Conference paper (Other academic)
    Abstract [en]

    The pellet consumption for single family house heating in Sweden is increasing strongly. Pellet stoves and boilers for domestic heating are becoming increasingly popular and new stove models with gas-liquid heat exchangers have entered the market. There is a need for computer models of the stoves, in order to perform simulation studies. The objective of this work was to evaluate pellet stoves and to make mathematical models of them for use in simulations of heating systems with TRNSYS. Three pellet stoves, one traditional and two with gas-liquid heat exchangers, and one pellet burner were tested in a combustion laboratory. A mathematical two-node model of a stove was developed and implemented as a TRNSYS component. A number of heat transfer coefficients and thermal masses of the stoves were identified. The calculated performance of the stoves agreed well with the measured data. The stove model was used in extensive TRNSYS simulations of yearly performance of single-family house heating systems. The simulations showed that the emissions, the yearly efficiency of a stove and the savings of auxiliary electric energy for heating may vary significantly depending on system design and control strategy.

  • 32. Nordlander, Svante
    et al.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Fiedler, Frank
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Computer modelling of wood pellet stoves and boilers connected to solar heating systems2006In: Proc on USB of Pellets 2006, 30 May - 1 June, Jönköping, Sweden, Jönköping, Sweden, 2006Conference paper (Other academic)
    Abstract [en]

    When optimizing systems for wood pellet and solar heating, there is a need for realistic computer models of stoves and boilers in order to perform simulation studies. The objective of this work was to develop and verify a mathematical model for wood pellet stoves and boilers for use in system simulations with TRNSYS calculating both the energy balance and CO-emissions (carbon monoxide). Laboratory measurements have been carried out on three pellet stoves, one traditional and two with gas-liquid heat exchangers, and four pellet boilers. A mathematical two-node model of a stove was developed and implemented as a TRNSYS component. Parameters were identified for two stoves and three boilers. This new model makes it possible to perform detailed simulations with time steps less than a minute of complete wood pellet heating systems and to derive long term values, such as annual values, of efficiency and emissions for the boiler or stove in a system context under realistic conditions. In addition, parametric studies can be used in order to investigate how different operation principles and system design affect these values. The simulated energy balance of a water jacketed stove investigated in this work agreed well with measured data during both stationary and dynamic conditions.

  • 33. Papillon, Philippe
    et al.
    Albaric, Mickael
    Haller, Michel
    Haber, Robert
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Pettersson, Ulrik
    Frank, Elimar
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Whole system testing: the efficient way to test and improve solar combisystems performance and quality2011In: ESTEC 2011 Conference Proceedings, Marseille, France, 2011Conference paper (Other academic)
    Abstract [en]

    The market for small solar combisystems has so far stayed way behind its huge potential. One of the reason may be that the quality and the thermal efficiency of the systems installed in the field is often lower than expected. Compact prefabricated systems have the potential to substantially reduce the effort and cost for their installation. Nevertheless, thermal efficiency should be clearly evaluated by lab testing. Until now it has been difficult to determine an accurate performance rating for those systems, and even more difficult to compare them, because there were no common definitions of terms for that type of system. For the development of the market of compact pre-fabricated solar combisystems, the existence of uniform test methods, recognized by the whole solar industry, is important. As a first step towards this goal, this paper give an overview of the information given to the manufacturer by these methods in term of thermal efficiency and knowledge of their product. The objective of the complete system test is to evaluate the thermal efficiency of complete systems including storage, controller, auxiliary boiler, pumps, valves, etc., in the laboratory thanks to a semi-virtual approach where climate, collector field, building and domestic hot water draw off are emulated. Based on this, three different test methods lasting 6 to 12 days have been developed and successfully applied to a number of small compact solar combisystems. Unlike field tests that need much more time to show the behaviour and performance of a system for a whole year, this kind of test method produces comparable results within a few weeks. The whole system test reveals unexpected behaviour of the systems in most cases and in some cases this behaviour was also detrimental to the system performance. The manufacturers like this kind of test method not only for getting independent test results that show the potential of their system, but also for testing prototypes prior to market introduction. This can be explained by the fact that this kind of test gives reliable function control and performance data within a few weeks. This data is more detailed and has a higher accuracy than what the manufacturer can expect from a whole year of field test monitoring. The test methods are suited for the determination of the annual performance of solar combisystems, including also a full evaluation of their functions and interactions.

  • 34.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Att konvertera från el till pellet och sol2004In: VVS TEKNIK & INSTALLATION, Vol. Oktober 2004, p. 44-47Article in journal (Other academic)
  • 35.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering. KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Combined solar and pellet heating systems for single-family houses: How to achieve decreased electricity usage, increased system efficiency and increased solar gains2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In Sweden, there are about 0.5 million single-family houses that are heated by electricity alone, and rising electricity costs force the conversion to other heating sources such as heat pumps and wood pellet heating systems. Pellet heating systems for single-family houses are currently a strongly growing market. Future lack of wood fuels is possible even in Sweden, and combining wood pellet heating with solar heating will help to save the bio-fuel resources. The objectives of this thesis are to investigate how the electrically heated single-family houses can be converted to pellet and solar heating systems, and how the annual efficiency and solar gains can be increased in such systems. The possible reduction of CO-emissions by combining pellet heating with solar heating has also been investigated. Systems with pellet stoves (both with and without a water jacket), pellet boilers and solar heating have been simulated. Different system concepts have been compared in order to investigate the most promising solutions. Modifications in system design and control strategies have been carried out in order to increase the system efficiency and the solar gains. Possibilities for increasing the solar gains have been limited to investigation of DHW-units for hot water production and the use of hot water for heating of dishwashers and washing machines via a heat exchanger instead of electricity (heat-fed appliances). Computer models of pellet stoves, boilers, DHW-units and heat-fed appliances have been developed and the parameters for the models have been identified from measurements on real components. The conformity between the models and the measurements has been checked. The systems with wood pellet stoves have been simulated in three different multi-zone buildings, simulated in detail with heat distribution through door openings between the zones. For the other simulations, either a single-zone house model or a load file has been used. Simulations were carried out for Stockholm, Sweden, but for the simulations with heat-fed machines also for Miami, USA. The foremost result of this thesis is the increased understanding of the dynamic operation of combined pellet and solar heating systems for single-family houses. The results show that electricity savings and annual system efficiency is strongly affected by the system design and the control strategy. Large reductions in pellet consumption are possible by combining pellet boilers with solar heating (a reduction larger than the solar gains if the system is properly designed). In addition, large reductions in carbon monoxide emissions are possible. To achieve these reductions it is required that the hot water production and the connection of the radiator circuit is moved to a well insulated, solar heated buffer store so that the boiler can be turned off during the periods when the solar collectors cover the heating demand. The amount of electricity replaced using systems with pellet stoves is very dependant on the house plan, the system design, if internal doors are open or closed and the comfort requirements. Proper system design and control strategies are crucial to obtain high electricity savings and high comfort with pellet stove systems. The investigated technologies for increasing the solar gains (DHW-units and heat-fed appliances) significantly increase the solar gains, but for the heat-fed appliances the market introduction is difficult due to the limited financial savings and the need for a new heat distribution system. The applications closest to market introduction could be for communal laundries and for use in sunny climates where the dominating part of the heat can be covered by solar heating. The DHW-unit is economical but competes with the internal finned-tube heat exchanger which is the totally dominating technology for hot water preparation in solar combisystems for single-family houses.

  • 36.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Delprojekt 3576 Integrerade system för sol och biobränsle: Slutrapport2011Report (Other academic)
  • 37.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Dishwasher and washing machine heated by a hot water circulation loop2007In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 27, no 1, p. 120-128Article in journal (Refereed)
    Abstract [en]

    Electric energy (70-90%) used by electrically heated dishwashers and washing machines is used for heating the water, the crockery, the laundry and the machine and could as well be replaced by heat from other sources than electricity. This article evaluates prototypes of a dishwasher and a washing machine, where the machines are heated by a hot water circulation loop and the heat is transferred to the machines via a heat exchanger. The machine therefore uses water from the cold water pipe. Measurements and simulations have been performed showing that all energy for heating can be replaced if the supply water temperature is 65-70 degrees C. An alternative and common way to save electricity is to connect the machines to the domestic hot water pipe, but the electrical savings with this measure are much smaller, especially for the dishwasher. Computer modelling has been performed and the model has proved to have a high agreement with measured data. However comparison with manufacturers' data indicates that the computer models overestimate the energy demand by about 10 %.

  • 38.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering. KTH, Energiteknik.
    Elbesparing med pelletkaminer och solvärme i direktelvärmda småhus2004Licentiate thesis, monograph (Other academic)
    Abstract [en]

    The aim of this study was to investigate how electricallyheated houses can be converted to using wood pellet and solarheating. There are a large number of wood pellet stoves on themarket. Many stoves have a water jacket, which gives anopportunity to distribute the heat to domestic hot water and aradiator heating system.

    Three typical Swedish houses with electric resistanceheating have been studied. Fourteen different system conceptsusing wood pellet stoves and solar heating systems have beenevaluated. The systems and the houses have been simulated indetail using TRNSYS. The houses have been divided in up to 10different zones and heat transfer by air circulation throughdoorways and open doors have been simulated. The pellet stoveswere simulated using a recently developed TRNSYS component,which models the start- and stop phases, emissions and thedynamic behaviour of the stoves. The model also calculates theCO-emissions. Simulations were made with one stove without awater jacket and two stoves with different fractions of thegenerated heat distributed in the water circuit.

    Simulations show that the electricity savings using a pelletstove are greatly affected by the house plan, the systemchoice, if the internal doors are open or closed and thedesired level of comfort. Installing a stove with awater-jacket connected to a radiator system and a hot waterstorage has the advantage that heat can be transferred todomestic hot water and be distributed to other rooms. Suchsystems lead to greater electricity savings, especially inhouses having a traditional layout. It was found that not allrooms needed radiators and that it was more effective in mostcases t use a stove with a higher fraction of the heatdistributed by the water circuit.

    The economic investigation shows that installing a woodpellet stove without a water jacket gives the lowest totalenergy- and capital costs in the house with an open plan (fortoday's energy prices and the simulated comfort criteria). Inthe houses with a traditional layout a pellet stove givesslightly higher costs than the reference house having onlyelectrical resistance heating due to the fact that less heatingcan be replaced. The concepts including stoves with a waterjacket all give higher costs than the reference system, but theconcept closest to be economical is a system with a bufferstore, a stove with a high fraction of the heat distributed bythe water circuit, a new water radiator heating system and asolar collector.

    Losses from stoves can be divided into: flue gas lossesincluding leakage air flow when the stove is not in operation;losses during start and stop phases; and losses due to a highair factor. An increased efficiency of the stoves is importantboth from a private economical point of view, but also from theperspective that there can be a lack of bio fuel in the nearfuture also in Sweden. From this point of view it is alsoimportant to utilize as much solar heat as possible. Theutilization of solar heat is low in the simulated systems,depending on the lack of space for a large buffer store.

    The simulations have shown that the annual efficiency ismuch lower that the nominal efficiency at full power. Thesimulations have also shown that changing the control principlefor the stove can improve efficiency and reduce theCO-emissions. Today's most common control principle for stovesis the on/off control, which results in many starts and stopsand thereby high CO-emissions. A more advanced control varyingthe heating rate from maximum to minimum to keep a constantroom temperature reduces the number of starts and stops andthereby the emissions. Also the efficiency can be higher withsuch a control, and the room temperature will be kept at a moreconstant temperature providing a higher comfort.

  • 39.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Erfarenheten: Pellet och sol kan vara framtidens kombination2007In: Energi & Miljö, ISSN 1101-0568, no 8Article in journal (Other academic)
  • 40.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Identifiering av parametrar till ackumulatortanken Solus 1050 från Consolar: En metodbeskrivning2001Report (Other academic)
  • 41.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Identifiering av parametrar till ackumulatortanken Solus1050 från consolar - en metodbeskrivning2001Report (Other academic)
    Abstract [sv]

    This report describes the work done creating a computer model of a kombi tank from Consolar. The model was created with Presim/Trnsys and Fittrn and DF were used to identify the parameters. Measurements were carried out and were used to identify the values of the parameters in the model. The identifications were first done for every circuit separately. After that, all parameters are normally identified together using all the measurements. Finally the model should be compared with other measurements, preferable realistic ones. The two last steps have not yet been carried out, because of problems finding a good model for the domestic hot water circuit. The model of the domestic hot water circuit give relatively good results for low flows at 5 l/min, but is not good for higher flows. In the report suggestions for improving the model are given. However, there was not enough time to test this within the project as much time was spent trying to solve problems with the model crashing. Suggestions for improving the model for the domestic circuit are given in chapter 4.4. The improved equations that are to be used in the improved model are given by equation 4.18, 4.19 and 4.22. Also for the boiler circuit and the solar circuit there are improvements that can be done. The model presented here has a few shortcomings, but with some extra work, an improved model can be created. In the attachment (Bilaga 1) is a description of the used model and all the identified parameters. A qualitative assessment of the store was also performed based on the measurements and the modelling carried out. The following summary of this can be given: Hot Water Preparation The principle for controlling the flow on the primary side seems to work well in order to achieve good stratification. Temperatures in the bottom of the store after a short use of hot water, at a coldwater temperature of 12°C, was around 28-30°C. This was almost independent of the temperature in the store and the DHW-flow. The measured UA-values of the heat exchangers are not very reliable, but indicates that the heat transfer rates are much better than for the Conus 500, and in the same range as for other stores tested at SERC. The function of the mixing valve is not perfect (see diagram 4.3, where Tout1 is the outlet hot water temperature, and Tdhwo and Tdhw1 is the inlet temperature to the hot and cold side of the valve respectively). The outlet temperature varies a lot with different temperatures in the storage and is going down from 61°C to 47°C before the cold port is fully closed. This gives a problem to find a suitable temperature setting and gives also a risk that the auxiliary heating is increased instead of the set temperature of the valve, when the hot water temperature is to low. Collector circuit The UA-value of the collector heat exchanger is much higher than the value for Conus 500, and in the same range as the heat exchangers in other stores tested at SERC. Boiler circuit The valve in the boiler circuit is used to supply water from the boiler at two different heights, depending on the temperature of the water. At temperatures from the boiler above 58.2°C, all the water is injected to the upper inlet. At temperatures below 53.9°C all the water is injected to the lower inlet. At 56°C the water flow is equally divided between the two inlets. Detailed studies of the behaviour at the upper inlet shows that better accuracy of the model would have been achieved using three double ports in the model instead of two. The shape of the upper inlet makes turbulence, that could be modelled using two different inlets. Heat losses The heat losses per m3 are much smaller for the Solus 1050, than for the Conus 500 Storage. However, they are higher than those for some good stores tested at SERC. The pipes that are penetrating the insulation give air leakage and cold bridges, which could be a major part of the losses from the storage. The identified losses from the bottom of the storage are exceptionally high, but have less importance for the heat losses, due to the lower temperatures in the bottom. High losses from the bottom can be caused by air leakage through the insulation at the pipe connections of the storage.

  • 42.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Kombinerade bio- och solvärmesystem: Handbok för systemutformning2008Report (Other academic)
    Abstract [sv]

    Syftet med denna skrift är att sammanställa den kunskap som finns beträffande kombinerade pellet- och solvärmesystem för att på så sätt stödja företagen i deras systemutveckling. Denna skrift behandlar erfarenheter som gjorts inom forskning på sol och pellet och omsätter dessa i praktiska råd för systemutformning. Förslag ges på systemutformning, olika tekniska lösningar samt hur systemen bör styras. När solvärme och pellet skall kombineras finns det många möjligheter att koppla ihop systemen. Det finns olika traditioner i olika länder, vilket gör att systemlösningarna varierar från land till land. En generell slutsats är dock att konventionella svenska pannor med inbyggd varmvattenberedning inte är lämpliga i konventionella solvärmesystem. Det ger komplicerade systemlösningar och det är svårt att åstadkomma bra skiktning i tanken. I ett solvärmesystem är det viktigt att tanken kan laddas ur på ett sådant sätt att kraftig skiktning erhålls. Det betyder att tankens botten skall kylas ner till temperaturen på ingående kallvatten och att tankens mellersta del skall kylas till samma temperatur som radiatorreturen. Om solfångaren även vintertid kan arbeta med att förvärma kallvatten av 10 till 20ºC fås en betydligt bättre verkningsgrad på solfångaren än om radiator returen skall förvärmas, som i bästa fall ligger på en temperaturnivå på mellan 30 och 40ºC. Av denna anledning skall radiator returen placeras en bra bit upp från botten i ackumulatortanken och tappvattnet skall förvärmas i en slinga som börjar i tankens botten. Om det finns ett VVC-system måste systemet anslutas på ett speciellt sätt så att inte tankens skiktning störs. En annan viktig parameter i tankens utformning är att värmeförlusterna hålls låga, detta är viktigt för att klara tappvattenlasten mulna perioder och för att hålla energianvändningen låg. I moderna hus där tanken placeras i boutrymmet blir det också en komfortfråga för att undvika över-temperaturer i rummet där tanken placeras. För att få en bra isolering måste man se till att det finns ett lufttätt skikt över hela isoleringen som dessutom sluter tätt mot röranslutningar. Ofrivillig själv-cirkulation i anslutande kretsar som kan kyla av och blanda om ackumulatortanken skall förhindras med backventiler. Vid design av solfångarkretsen måste överhettning och stagnation kunna klaras utan glykolnedbrytning eller andra skador. Partiell förångning innebär att man låter solfångaren koka på ett kontrollerat sätt så att endast ånga blir kvar i solfångaren. Vätska samlas i ett större expansionskärl och systemet återfylls när vätskan kondenserar. Dränerande system med enbart vatten är också en möjlighet, men kräver större noggrannhet vid installationen så att sönderfrysning undviks. Pelletkaminer (luftburna) ger god komfort och lågt elbehov i direktelvärmda hus med öppen planlösning, dvs. om värmen från kaminen kan spridas till alla rum utan att behöva passera genom mer än en dörröppning. Även i lågenergihus kan den luftburna kaminen vara lämplig. I hus med mer sluten planlösning krävs en vattenmantlad kamin med hög andel värme till vattenkretsen och ett vattenburet värmesystem. Det är viktigt att sådana system utformas korrekt för att komforten skall bli hög och elanvändningen låg. Brukarens aspekter och komfortkrav måste beaktas vid användning av kaminer, eftersom det krävs en temperaturskillnad mellan olika rum för att få värmespridning från det rum där kaminen är placerad.

  • 43.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Konvertering av elvärmda hus till pellet- och solvärme - Beskrivning av datormodell för byggnader och system.2003Report (Other academic)
  • 44.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Lågtemperaturvärmesystem: en kunskapsöversikt2000Report (Other academic)
  • 45.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Modellering och simulering av tappvattenautomater i solvärmesystem2002Report (Other academic)
  • 46.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Mätning och utvärdering av PM brännaren2007Report (Other academic)
    Abstract [sv]

    The PM-brännaren (pellets burner) have on commission by the company been measured and evaluated in the combustion laboratory of SERC. The objective was to measure the perform-ance and the emissions of CO and NO for three different combustion powers and for start and stop conditions. The burner have been mounted in the Bionett-boiler from Ariterm and been adjusted by the company. The boiler has been connected to a buffer store that admits firing during long period with constant inlet temperature to the boiler. The measurements have been performed by operating the boiler on constant power until stationary conditions are reached. Thereafter the following two hours of operation have been evaluated. The results show that the burner fulfils the limit values for Blauer Engel labelling and the proposed limit values for Nordic Eco labelling. The measured concentration of NO is far below all organisations limit values for NOx. Concerning the start and stop emissions there are no demands from organisa-tions to compare with, but comparing with other boilers measured at SERC, the CO emissions from PM-brännaren is in the same order of magnitude.

  • 47.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Pellet och sol, ett bidrag till omställningen från el-uppvärmning, Lägesrapport från delprojekten: 1 Människor hus och värme; 2 Pelletbrännaren; 3 Värmesystemet2003In: Programkonferens, Småskalig bioenergianvändning och Utsläpp och luftkvalitet, Växjö, 2003Conference paper (Other academic)
  • 48.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Reglerprinciper för villasystem med pelletkaminer och solvärme2005Report (Other academic)
  • 49.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Sol och pellet för småhus: Systemutformningen påverkar kraftigt energianvändning och emissioner2007In: Energi & miljö, ISSN 1101-0568, no 1, Januari, p. 62-63Article in journal (Other academic)
    Abstract [sv]

    Sol och pellet är en mycket bra kombination om systemet utformas på ett bra sätt. Då kan pelletbesparingen bli betydligt större än den insamlade solenergimängden och utsläppen av CO (kolmonoxid) kan nästan halveras jämfört med att elda med enbart pellet. Pellet- och solvärmesystemets utformning är dock avgörande för hur stor energibesparingen med solvärme blir. Det visar ett forskningsprojekt som genomförts vid Centrum för solenergiforskning, Högskolan Dalarna.

  • 50.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Solar and Pellet Heating Systems: Reduced Electricity Usage in Single-family Houses2009Book (Other academic)
    Abstract [en]

    Pellet heating systems for single-family houses are currently a strongly growing market; however pellet heating is seldom installed together with solar heating, though it is a promising combination. The present book is based on the author's doctoral thesis written at KTH, the Royal institute of Technology in Stockholm, Sweden and investigates how electrically heated single-family houses can be converted to pellet and solar heating systems. There is a strong focus on system design and how to design and operate the systems so that the annual system efficiency and solar gains can be maximized. Technologies for increasing the solar gains are DHW- units for hot water production and the use of hot water for heating of dishwashers and washing machines via a heat exchanger instead of electricity (heat-fed appliances. The possible reduction of CO- emissions by combining pellet heating with solar heating are also investigated. The method is based on measurements modeling and system simulations using the dynamic simulation program TRNSYS.

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