This is a study presented by members of the Swiss Institut fÃ¼r Solartechnik during the ISES Solar Word Congress held in Kassel, Germany (28 August - 2 September 2011). Part of the IEA SHC Task 44, the paper researches the benefits and performances of using heat from solar collectors for the evaporator of the heat pump instead of using the heat directly.
The research focuses on the control of this dual system, namely switching between direct and indirect collector heat use. The comparison of the two modes of collector operation is done through the amount and temperature of the heat delivered to the systemâs storage. Employing a TRNSYS-type simulation software and testing the system under different climatic conditions, researchers were able to compare the different coefficients of performance in order to establish a clear set of results.
From the analysis of the option to use solar heat for the evaporator of a dual source heat pump instead of using it directly it can be concluded that this option has a higher potential for improving the overall systemâs energetic performance for systems with high temperatures on the demand side and low temperatures on the side of the heat source and the ambient air.
Author: Swiss Institut fÃ¼r Solartechnik
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