Abstract
Until recently, solar assisted heat pumps have used solar collectors as a cold source. Solar collectors provide, when possible, direct heat, otherwise they offer temperature levels to the heat pump evaporator higher than the outside air. At the same time, solar thermal cooling exploits the solar collectors and the absorption chiller only in hot months. Photovoltaic/Thermal (PVT) modules have been available on the market in recent years for solar cogeneration, but their utilization can be problematic due to PhotoVoltaic (PV) cell damage in cases where there is no heating request. This paper considers the possibility of coupling evacuated tube collectors and photovoltaic/thermal modules to drive an absorption heat pump-based plant operating as an absorption chiller in the summertime. The cold source is the solar energy and the ground, which is recharged by the solar thermal and photovoltaic/thermal collectors and by the cooling of the absorber-condenser in mid-seasons and summer. This study analyzes the system behavior in yearly operation and evaluates the role of suitable storage tanks in two different climates, varying the size of the two solar fields and the generator tank. In the best plant configuration, a primary energy ratio of 26.6 in colder climates with cloudy skies and 20 in hotter climates with clearer skies is obtained.
Highlights
The cooling and heating of buildings results in a very high global energy demand; about 30–45%, depending of the country [1]
Even though the Energy Performance of Buildings Directive (EPBD) requires that all new buildings in the European Union be nearly zero energy buildings (NZEB) by the end of 2020 [2], heating and cooling demands remain high for existing buildings, even after refurbishment
Solar energy can contribute to meeting the heating and cooling demands of buildings by solar electricity or by solar thermally driven processes [3,4]
Summary
The cooling and heating of buildings results in a very high global energy demand; about 30–45%, depending of the country [1]. An interesting option to increase the attractiveness of solar thermally driven systems, when compared to the more competitive PV heating and cooling systems, could be the utilization of ETCs as a means of driving energy at the generator of a thermally driven heat pump, rather than just their traditional use as a heat source (at the evaporator) Nowadays, this can be possible thanks to technical improvements in solar thermal collectors over the last few years [3]. The performance depends on the climate of the resort considered, on the outside air temperature and the clearness index For such an annual utilization of solar thermal energy, a thermally driven chiller that can operate as a heat pump with suitable temperatures at the three heat exchangers (generator, evaporator, absorber/condenser) has to be coupled. The results of simulations allow us to assess the size of the main equipment of the solar heating and cooling plant in order to make it sufficiently sustainable from an energy point of view when compared to a traditional air/water (A/W) electric chiller/heat pump system
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
