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Wang, X., Xia, L., Bales, C., Zhang, X., Copertaro, B., Pan, S. & Wu, J. (2020). A systematic review of recent air source heat pump (ASHP) systems assisted by solar thermal, photovoltaic and photovoltaic/thermal sources. Renewable energy, 146, 2472-2487
Open this publication in new window or tab >>A systematic review of recent air source heat pump (ASHP) systems assisted by solar thermal, photovoltaic and photovoltaic/thermal sources
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2020 (English)In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 146, p. 2472-2487Article in journal (Refereed) Published
National Category
Energy Engineering
Research subject
Energy and Built Environments
Identifiers
urn:nbn:se:du-30632 (URN)10.1016/j.renene.2019.08.096 (DOI)2-s2.0-85071196687 (Scopus ID)
Available from: 2019-08-23 Created: 2019-08-23 Last updated: 2019-09-17Bibliographically approved
Shen, J., Copertaro, B., Sangelantoni, L., Zhang, X., Suo, H. & Guan, X. (2020). An early-stage analysis of climate-adaptive designs for multi-family buildings under future climate scenario: Case studies in Rome, Italy and Stockholm, Sweden. Journal of Building Engineering, 27, Article ID 100972.
Open this publication in new window or tab >>An early-stage analysis of climate-adaptive designs for multi-family buildings under future climate scenario: Case studies in Rome, Italy and Stockholm, Sweden
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2020 (English)In: Journal of Building Engineering, E-ISSN 2352-7102, Vol. 27, article id 100972Article in journal (Refereed) Published
National Category
Civil Engineering
Research subject
Energy and Built Environments
Identifiers
urn:nbn:se:du-31015 (URN)10.1016/j.jobe.2019.100972 (DOI)2-s2.0-85073097183 (Scopus ID)
Available from: 2019-10-22 Created: 2019-10-22 Last updated: 2019-10-22Bibliographically approved
Shen, J., Copertaro, B., Sangelantoni, L., Zhang, X., Suo, H. & Guan, X. (2020). An early-stage analysis of climate-adaptive designs for multi-family buildings under future climate scenario: case studies in Rome, Italy and Stockholm, Sweden. Journal of Building Engineering, 27, Article ID 100972.
Open this publication in new window or tab >>An early-stage analysis of climate-adaptive designs for multi-family buildings under future climate scenario: case studies in Rome, Italy and Stockholm, Sweden
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2020 (English)In: Journal of Building Engineering, E-ISSN 2352-7102, Vol. 27, article id 100972Article in journal (Refereed) Published
Abstract [en]

This paper presents a preliminary case study for climate-adaptive residential multifamily building designs located in urban centre at early stage, to allow thermal comfort and minimum energy use from today to the last part of 21st century. The generated future climate data combined with comfort model assessment has been proposed as a new way including future climate scenarios in preliminary building design for two representative sites, in Rome, Italy and Stockholm, Sweden. The existing vulnerability to the expected climate conditions from psychometric analysis indicates that: (1) the climate trend in Rome would gradually lead to more failures in the majority of conventional adaptive design measures, as the cooling and dehumidification demands would rise from 5.3% to 23.6%, while the heating and humidification demands would decrease from 27% to 16%; (2) the climate trend in Stockholm would result in an increased comfort period by exploiting more adaptive design measures, since the heating and humidification demands would be reduced from 67% to 53%. However, the cooling and dehumidification demands would increase slightly from 0% to 1.5%. Accordingly, four main key risks are identified: 1) overheating would become a rising increasing public health threat for buildings in Rome that rely exclusively on natural ventilation; 2) open questions remain for the design team in the area of correct cooling load selection, additional space for the future installation and the effectiveness of current cooling device etc.; 3) occasional heat waves and gradual rising humidity levels are expected to be a vulnerable topic for conventional lightweight building in Stockholm; 4) buildings with a heavy heating load would tend to have greater cooling demand, especially those with poor ventilation resources or greater internal gains. In conclusion, it is suggested that envelope optimization, whichever climate type, is one of the most efficient and effective adaptation measures towards future climate conditions.

Keywords
Climate Change; Weather data morphing; Climate Adaptive Building Design; Thermal Comfort model; Psychrometric Analysis
National Category
Civil Engineering
Research subject
Energy and Built Environments, ENSECO - Produktion och process för utformning och konstruktion av energisjälvförsörjande containerbyggnader
Identifiers
urn:nbn:se:du-30824 (URN)
Projects
Energiinnovation i Sverige
Available from: 2019-09-30 Created: 2019-09-30 Last updated: 2019-11-26Bibliographically approved
Li, Y., Rezgui, Y., Guerriero, A., Zhang, X., Han, M., Kubicki, S. & Yan, D. (2020). Development of an adaptation table to enhance the accuracy of the predicted mean vote model. Building and Environment, 168, Article ID 106504.
Open this publication in new window or tab >>Development of an adaptation table to enhance the accuracy of the predicted mean vote model
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2020 (English)In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 168, article id 106504Article in journal (Refereed) Published
National Category
Building Technologies
Research subject
Energy and Built Environments
Identifiers
urn:nbn:se:du-31070 (URN)10.1016/j.buildenv.2019.106504 (DOI)2-s2.0-85074601389 (Scopus ID)
Available from: 2019-11-01 Created: 2019-11-01 Last updated: 2019-11-26Bibliographically approved
Huang, P., Fan, C., Zhang, X. & Wang, J. (2019). A hierarchical coordinated demand response control for buildings with improved performances at building group. Applied Energy, 242, 684-694
Open this publication in new window or tab >>A hierarchical coordinated demand response control for buildings with improved performances at building group
2019 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 242, p. 684-694Article in journal (Refereed) Published
Abstract [en]

Demand response control is one of the common means used for building peak demand limiting. Most of the existing demand response controls focused on single building’s performance optimization, and thus may cause new undesirable peak demands at building group, imposing stress on the grid power balance and limiting the economic savings. A few latest studies have demonstrated the potential benefits of demand response coordination, but the proposed methods cannot be applied in large scales. The main reason is that, for demand response coordination of multiple buildings, associated computational load and coordination complexity, increasing exponentially with building number, are challenges to be solved. This study, therefore, proposes a hierarchical demand response control to optimize operations of a large scale of buildings for group-level peak demand reduction. The hierarchical control first considers the building group as a ‘virtual’ building and searches the optimal performance that can be achieved at building group using genetic algorithm. To realize such optimal performance, it then coordinates each single building’s operation using non-linear programming. For validations, the proposed method has been applied on a case building group, and the study results show that the hierarchical control can overcome the challenges of excessive computational load and complexity. Moreover, in comparison with conventional independent control, it can achieve better performances in aspects of peak demand reduction and economic savings. This study provides a coordinated control for application in large scales, which can improve the effectiveness and efficiency in relieving the grid stress, and reduce the end-users’ electricity bills.

Keywords
Peak demand limiting, Demand response, Building group coordination, Economic cost, Grid interaction
National Category
Energy Engineering
Research subject
Energy and Built Environments
Identifiers
urn:nbn:se:du-29729 (URN)10.1016/j.apenergy.2019.03.148 (DOI)000470045800054 ()2-s2.0-85063025035 (Scopus ID)
Available from: 2019-03-20 Created: 2019-03-20 Last updated: 2019-07-22Bibliographically approved
Huang, P., Fan, C., Zhang, X. & Wang, J. (2019). A hierarchical coordinated demand response control for buildings with improved performances at building group. Applied Energy, 242, 684-694
Open this publication in new window or tab >>A hierarchical coordinated demand response control for buildings with improved performances at building group
2019 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 242, p. 684-694Article in journal (Refereed) Published
Abstract [en]

Demand response control is one of the common means used for building peak demand limiting. Most of the existing demand response controls focused on single building’s performance optimization, and thus may cause new undesirable peak demands at building group, imposing stress on the grid power balance and limiting the economic savings. A few latest studies have demonstrated the potential benefits of demand response coordination, but the proposed methods cannot be applied in large scales. The main reason is that, for demand response coordination of multiple buildings, associated computational load and coordination complexity, increasing exponentially with building number, are challenges to be solved. This study, therefore, proposes a hierarchical demand response control to optimize operations of a large scale of buildings for group-level peak demand reduction. The hierarchical control first considers the building group as a ‘virtual’ building and searches the optimal performance that can be achieved at building group using genetic algorithm. To realize such optimal performance, it then coordinates each single building’s operation using non-linear programming. For validations, the proposed method has been applied on a case building group, and the study results show that the hierarchical control can overcome the challenges of excessive computational load and complexity. Moreover, in comparison with conventional independent control, it can achieve better performances in aspects of peak demand reduction and economic savings. This study provides a coordinated control for application in large scales, which can improve the effectiveness and efficiency in relieving the grid stress, and reduce the end-users’ electricity bills.

Keywords
Peak demand limiting, Demand response, Building group coordination, Economic cost, Grid interaction
National Category
Building Technologies
Research subject
Energy and Built Environments
Identifiers
urn:nbn:se:du-30843 (URN)10.1016/j.apenergy.2019.03.148 (DOI)
Available from: 2019-09-30 Created: 2019-09-30 Last updated: 2019-10-01Bibliographically approved
Huang, P., Copertaro, B., Zhang, X., Shen, J., Löfgren, I., Rönnelid, M., . . . Svanfeldt, M. (2019). A review of data centers as prosumers in district energy systems: Renewable energy integration and waste heat reuse for district heating. Applied Energy
Open this publication in new window or tab >>A review of data centers as prosumers in district energy systems: Renewable energy integration and waste heat reuse for district heating
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2019 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118Article in journal (Refereed) In press
Abstract [en]

As large energy prosumers in district energy systems, on the one hand, data centers consume a large amount of electricity to ensure the Information Technologies (IT) facilities, ancillary power supply and cooling systems work properly; on the other hand, data centers produce a large quantity of waste heat due to the high heat dissipation rates of the IT facilities. To date, a systematic review of data centers from the perspective of energy prosumers, which considers both integration of the upstream green energy supply and downstream waste heat reuse, is still lacking. As a result, the potentials for improving data centers’ performances are limited due to a lack of global optimization of the upstream renewable energy integration and downstream waste heat utilization. This study is intended to fill in this gap and provides such a review. In this regard, the advancements in different cooling techniques, integration of renewable energy and advanced controls, waste heat utilization and connections for district heating, real projects, performance metrics and economic, energy and environmental analyses are reviewed. Based on the enormous amount of research on data centers in district energy systems, it has been found that: (1) global controls, which can manage the upstream renewable production, data centers’ operation and waste heat generation and downstream waste heat utilization are still lacking; (2) regional climate studies represent an effective way to find the optimal integration of renewable energy and waste heat recovery technologies for improving the data centers’ energy efficiency; (3) the development of global energy metrics will help to appropriately quantify the data center performances.

Keywords
Data center, District energy system, Renewable energy, Waste heat recovery, Energy efficiency
National Category
Energy Engineering
Research subject
Energy and Built Environments
Identifiers
urn:nbn:se:du-31116 (URN)10.1016/j.apenergy.2019.114109 (DOI)2-s2.0-85075714407 (Scopus ID)
Available from: 2019-11-20 Created: 2019-11-20 Last updated: 2019-12-09Bibliographically approved
Li, G., Tang, L., Zhang, X. & Dong, J. (2019). A review of factors affecting the efficiency of clean-in-place procedures in closed processing systems. Energy, 178, 57-71
Open this publication in new window or tab >>A review of factors affecting the efficiency of clean-in-place procedures in closed processing systems
2019 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 178, p. 57-71Article in journal (Refereed) Published
Abstract [en]

This paper reviews the current state of researches on improvement of Clean-In-Place (CIP) procedures in closed processing system thus saving energy, with a special attention paid to the hydrodynamic effects of cleaning fluid and the numerical and experimental approaches to investigate the identified controlling factors. The paper discussed the fouling problems of processing plants and the importance of sufficient CIP procedures, the forces contributing to cleaning with a special focus on the hydrodynamic effects. In general, it is possible to enhance hydrodynamic removal forces by local introduction of, among others, high wall shear stress and fluctuation rate of wall shear stress without consuming more energy. A theoretical model of particle removal in flow was also reviewed which supports the factors identified. The paper therefore further reviewed and compared the current state of modelling and experimental techniques on CIP improvement. To simulation the CIP process, it is necessary to consider 3D time-resolved Large Eddy Simulation with a Hybrid RANS-LES WMLES as Sub-Grid-Scale model because it captures both the mean and fluctuation rate of flow variables, while affordable for industrial flows. The wall shear stress measurement techniques and cleanablity test methods were also discussed and suggested.

Keywords
Clean-in-place, Efficiency, Hydraulic factors, Wall shear stress, CFD
National Category
Environmental Engineering
Research subject
Energy and Built Environments
Identifiers
urn:nbn:se:du-30009 (URN)10.1016/j.energy.2019.04.123 (DOI)000472686300005 ()2-s2.0-85065074591 (Scopus ID)
Available from: 2019-05-10 Created: 2019-05-10 Last updated: 2019-07-22Bibliographically approved
Han, M., May, R., Zhang, X., Wang, X., Pan, S., Yan, D., . . . Xu, L. (2019). A review of reinforcement learning methodologies for controlling occupant comfort in buildings. Sustainable cities and society, 51, Article ID 101748.
Open this publication in new window or tab >>A review of reinforcement learning methodologies for controlling occupant comfort in buildings
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2019 (English)In: Sustainable cities and society, ISSN 2210-6707, Vol. 51, article id 101748Article in journal (Refereed) Published
National Category
Building Technologies
Research subject
Complex Systems – Microdata Analysis
Identifiers
urn:nbn:se:du-30601 (URN)2-s2.0-85070980900 (Scopus ID)
Available from: 2019-08-08 Created: 2019-08-08 Last updated: 2019-10-11Bibliographically approved
Zhang, X., Wu, J., Pan, S. & Han, M. (2019). An economic analysis of the solar photovoltaic/thermal (PV/T) technologies in Sweden: A case study. In: IOP Conference Series: Materials Science and Engineering. Paper presented at Solaris 2018, The 9th edition of the international SOLARIS conference30th-31st of August, 2018, Chengdu, China. , 556(1), Article ID 012002.
Open this publication in new window or tab >>An economic analysis of the solar photovoltaic/thermal (PV/T) technologies in Sweden: A case study
2019 (English)In: IOP Conference Series: Materials Science and Engineering, 2019, Vol. 556, no 1, article id 012002Conference paper, Published paper (Refereed)
National Category
Energy Engineering
Research subject
Energy and Built Environments
Identifiers
urn:nbn:se:du-30821 (URN)10.1088/1757-899X/556/1/012002 (DOI)2-s2.0-85072132529 (Scopus ID)
Conference
Solaris 2018, The 9th edition of the international SOLARIS conference30th-31st of August, 2018, Chengdu, China
Available from: 2019-09-27 Created: 2019-09-27 Last updated: 2019-09-27Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-2369-0169

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