ANNUAL OPERATION PERFORMANCE AND HOURLY WORKING MODE OPTIMIZATION OF DIRECT EXPANSION SOLAR-AIR DUAL SOURCE HEAT PUMP
Based on the energy balance and the heat transfer characteristics of the collector-evaporator,a system simulation model of a dual-source heat pump is established.The heat pump combines a finned tube air-cooled evaporator and a roll-bond plate double-sided solar collector-evaporator in parallel,and the model considers the real-time solar radiation heat gain on the front and back of the roll-bond plate evaporator.Based on the annual meteorological parameters,the annual operation performance of the heat pump in Shanghai is simulated to analyze the effect of solar collector area on the performance of the heat pump.Based on the optimized collector-evaporator area,the annual operation performance of three working modes of the dual-source heat pump is compared and analyzed.Aiming at the highest hourly COP,the optimal working mode of the heat pump is obtained hour by hour.The simulation results show that:for the double-sided roll-bond plate evaporator installed at 45-degree tilt towards the south,the solar radiation heat gain on the back is 3%-15%of that on the front;the annual COP of the dual-source heat pump in parallel operation mode is 24.2%and 2.5%higher than that of single air-source heat pump and single solar energy heat pump respectively.The discrimination rule of the hourly optimal working mode of the dual-source heat pump expressed by the total horizontal irradiance Ig and the ambient temperature Ta is obtained:when Ig>25.05Ta-146.8,the optimal working mode of the system is the solar mode;when Ig<25.05Ta-146.8,the optimal working mode is the solar-air source parallel mode.In the hourly optimal working mode,the annual COP of the heat pump is increased by 4.7%and the winter COP is increased by 11.0%relative to the fixed dual-source parallel operation mode.
solar energyheat pump systemair source heat pumpcoefficient of performancehourly mode optimization
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维普
