| In recent years,environmental protection pressure have continuously escalated and environmental pollution control efforts have been continuously strengthened.As one of the three major energy consumptions,heating and air conditioning account for about 65% of building energy consumption.How to reduce building energy consumption is also one of the focuses of experts from various countries.At present,the main energy-saving method is to improve the system performance coefficient in the original heating and air-conditioning mode to achieve the purpose of energy saving.The solar-assisted heat pump system has begun to enter people’s lives with its good heating and air-conditioning effects and superior energy-saving properties to realizes air conditioning in summer and heating in winter.With the deepening of research,the system has been continuously optimized in terms of automatic control and energy saving,and the system has become more and more mature.This paper introduces a new type of solar-assisted heat pump system.The air source heat pump system and the solar thermal collector system are coupled together through a plate heat exchanger to provide heat for the building.In summer,the solar thermal cycle is turned off,and the air source heat pump alone provides cooling for the room;In the winter and transition season,the low-temperature hot water generated by solar energy is exchanged with the hot return water in the plate heat exchanger and flows into the heat pump unit condenser for reheating and hot water after heating flows into heating end.When the temperature of the hot water generated by the solar collector is high enough,the water temperature can be reached the temperature of supply water directly after heat exchange in the plate heat exchanger.The system can make full use of solar energy,reduce system energy consumption,and achieve energy-saving goals.The composition of solar-assisted heat pump system is introduced in this article.The project is equipped with 2 sets of 6P low temperature heating and cooling machines and 20 sets of flat plate collectors.According to weather characteristics and analysis needs,select and analyze the data on January 4,10,19,30,and March 9,2018.For example,when the ambient temperature is-6~1°C(winter testing day January 10,2018),the room temperature can reach 20°C or more.When the outdoor temperature is below 0°C,the maximum temperature of the collector can reach 60°C.At noon time,as the solar irradiance gradually reaches its maximum value,the hot water prepared by solar energy basically meets the room heating demand,the power consumption of the heat pump is reduced by nearly 81%,and the COP of the heat pump also reaches a maximum value of 5.48.Analysis of system energy efficiency in January,the minimum daily average COP of the system is 2.75 and the maximum is 6.43,which is 18.2%~70% higher than that of the heat pump unit,and the energy saving effect is obvious.A systematic cop comparison analysis was conducted on the 5 days test days for different weather conditions.It was found that the solar irradiance had a greater impact on the heating performance of the system.The statistics of January’s operating data are collected,monthly energy consumption of 888 kWh,total heating capacity of 3969kWh(including nighttime energy consumption),heat pump heating capacity of 2472.9kWh,solar heat collection capacity of 1496.1kWh.The solarassisted heat pump system can save 37.7% energy than the air source heat pump alone.In January,the overall system COP was 4.47.Heating the solar-assisted air source heat pump system can effectively improve the COP of the heating system.Compared with other heating methods,the energy consumption of the solar-assisted heat pump system is only 21.5% of the energy consumption of electric boilers,and 57.2% of gas boilers,with excellent energy-saving and environmental benefits. |
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