In comparison with conventional power plants and other renewable technologies,
the current cost of a Concentrating Solar Power plant is still very high. This
situation has made the industry have the necessity to research in this field to
improve efficiency and for a near future have lower cost. One of the developed field
to improve the efficiency is to decrease the heat losses in the system therefore,
having a better efficiency in the system.
In this project, in collaboration of the Solar Platform of Almeria (PSA) in Spain, the
purpose was to analyses the heat losses of a commercial parabolic trough solar
receiver at different pressures inside the receiver (at the annulus space). The
objective was finding the behavior of the heat losses as the pressure inside the
receiver is increasing allowing convection between the absorber and the glass
envelope. The PSA has developed a test bench in order to test any kind of linear
solar receptor named HEATREC. The HEATREC allows to measure the heat
losses of the receiver in a controlled environment at different temperatures. The
receiver suffered a minor modification so the pressure in the annulus space can be
control at will.
The results shown in this experiment are represented mainly in two types of
graphics. The first type shows the heat losses as a function of the temperature of
the absorber tube, this one is used as a comparison with previews research to see
if is having a correct behavior regardless the pressure in the annulus space is
being change. The second type shows the heat losses as a function of the
pressure in the annulus space inside the receiver. The experimental data show that
there is a remarkable increase in the heat losses as the pressure inside the
annulus space of the receiver increase and that it can be seen that there are two
major points in the pressure where the heat losses increase drastically (from 10# to
10$ mbar and from 10%& to 10%# mbar).
2016.