| People had pay more attention to the use of renewable energy with the rapidly increased of energy consumption in the world. The solar energy had become more important because of its safety, non-polluting, etc. In recent years, the total building energy consumption had rapidly increased with the development of society in our county. The energy consumption of HVAC system and hot water system were about 60 percent of the total building energy consumption. So it was very important to invent a system which intergrated solar photovoltaic/thermal and heat pump water heating system. The system could not only realize the photovoltaic power generation, but also could provide the building with hot water for living. So it became an effective measure to decrease the power of energy. This paper was focused on the multi-port tube to build solar-air photovoltaic/thermal composite air source heat pump water heating system. Then made lots of related theoretical and experimental studies which aimed to improve the photovoltaic/thermal output characteristics and commercialization of the system.Firstly, based on the popular machining process of commercial PV modules, an unglazed photovoltaic/thermal collector with polycrystalline silicon was manufactured. There were 5 multi-port tubes which can absorb solar energy on the back of the collector. The size of the tube was 25mm×2.5 mm, and each tube had six small-size rectangle flow channels inside. A new type of solar photovoltaic/thermal integrated heat pump (PV/T-HP) hot water system was built which used the collector and air-cooled pipe-finned exchanger as kernel part.Secondly, three different operating modes were proposed in this study which include double heat source operation mode, singel solar energy operation mode and single air energy operation mode. With 200 L hot water heated from 30? to 55? by the system. The performances of this system were evaluate experimentally under different operating modes. Experimental results showed that the running time of double heat source operation was shorter than that of single air energy operation and single solar energy operation, decreased by 42% and 54%, COPs were increased by 32.78% and 47.64%, respectively under summer condition.The running time of double heat source operation was shorter than that of single air energy operation and single solar energy operation, decreased by 29.7% and 45.8%, COPs were increased by 22.1% and 39.0%, respectively under spring condition.Besides, the mathematical models about plate type evapotator, compressor, condenser and expansion valve were built. The simulation and error analysis of the system were carried out under the condition that the ambient temperature was 30?. The results showed the maximum error of heating time between values of simulation and experimental datas was 5.14%, and the minimum error was 0.20%. The maximum error of COP between values of simulation and experimental datas was 18.67%, and the minimum error was 1.44%.Finally, the system's thermodynamic and photovoltaic output characteristics for heating 200 L water were investigated experimentally. The performance of system was studied both of electro-optic pattern and electro-thermal pattern. The photovoltaic and thermal output characteristic were analyzed in detail which based on solar irradiance, amient temperature and collectors' temperature, etc. The results showed the average efficiency of optic-thermal was 55% under summer condition. The efficiencies of optic-electro were 15.4% and 12.4% in electro-thermal and electro-optic patterns under summer condition. The average efficiency of optic-thermal was 53.5%% under spring condition. The efficiencies of optic-electro were 21.5% and 18.5% in electro-thermal and electro-optic patterns under spring condition. All of the analysis provided the data support for the popularity of the system. |
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