Simulation Study And Economic Analysis On Photovoltaic-Solar Assisted Heat Pump System

Well known as a non-polluting, inexhaustible, and clean energy source, solar energy has received considerable attention at present, while the energy and the environmental issue increasing significant. This paper take the compound photovoltaie/thermal utility to study Photovoltaic Solar Assisted Heat Pump system (PV-SAHP).In PV-SAHP, a specially designed direct expansion PV/T solar collector with PV cells laminated on the front surface is employed in the system to act as the evaporator (PV-EVAP). On one hand, because refrigerant absorbed unnecessary heat from the PV base plate in the evaporator, the system can mainiain the PV cell in a lower temperature for better photovoltaic performance. On the other hand, the coefficient of performance of PV-SAHP is obviously improved because the evaporating process under insolation. The system can also generate electricity and heat energy in the meantime. This improves the overall utilization of solar energy efficiency.First in this paper, a steady-state phase-separating lumped parameters approach has been used to simulate the PV-EVAP in depth, which is the core component of PV-SAHP system. Researches were focused on the environmental parameters, structural parameters and inlet parameters of the evaporator, which influenced the outlet enthalpy of the PV-EVAP. After that, numerical simulation has been performed for predicting the behavior of the evaporator in whole day, according to specified instantaneous solar irradiance, ambient temperature and inlet parameters of the evaporator. The results demonstrate that PV-EVAP has a superior performance. The average thermal efficiency, electrical efficiency and the overall efficiency of the PV-EVAP are around 13.3%,67.9% and 79.2% respectively. Compared to a traditional PV/T collector the overall efficiency was 10% higher. Besides, the results also show that the photovoltaic and thermal performance mainly depend on the soiar irradiance. The ambient temperature also can effect the performance of PV-EVAP.Second, a model for the PV-SAHP system is then established and numerical simulation is performed for predicting the behavior of the system in whole day. The results show that high performance can be obtained by the system. The average output electricity, electrical efficiency, COP, and COPe-t are around 462.1W,13.8%,5.89 and 9.13 respectively. The compressor power consumption is about 78.2% of the output electricity, which means that the system can offer all the power consumed by itself.Finally, according to the economic analysis and the environmental benefits evaluation on the photovoltaic-solar assisted heat pump water heater, it shows that the system can save expenses, reduce energy consumption and decrease emissions of pollutants. PV-SAHPWH is suitable for supplying hot water and electrical energy to residence community, and it is also worth to be applied to practical engineerings.