Performance Study On An Air-source Heat Pump Assisted Domestic Solar Water Heating System

With the rapid development of construction, building energy consumption is daily on the increase, and different energy saving technology is studied and used more widely. The air-source heat pump assisted solar water heating system is integrated with the solar energy heat utilization technology and the air-source heat pump, and hence paid close attention for its high-efficient heat-collection, energy-saving operation and diversity systems.The designed air-source heat pump assisted domestic solar water heating system (ASHP-SWHS) is improved further on the foundation of the researches which have finished by the research group. Then the parameters and types of different constituent parts of the ASHP-SWHS are confirmed, and the elementary experimental model is made and debugged finally. Meantime, meteorological data of the typical meteorological year in Xi'an is deeply and particularly analyzed deeply and particularly by statistical method, and the typical meteorological year is divided into three parts by different radiation-metering times. The hourly meteorological parameter of different periods and different weather regimes (DPDW) of the whole year are achieved, including the daily average hourly horizontal global radiation on the ground, daily average hourly horizontal direct- radiation, daily average hourly horizontal scattering-radiation and daily average hourly temperature. The radiation on the solar heat-collector is calculated which then is transformed into heat, and the daily average hourly water temperature is achieved to determine the optimal operational mode of an air-source heat pump assisted domestic solar water heating system during the DPDW. The equipment of PC-2 radiation-measuring is using for testing and recording the hourly meteorological parameter of radiation from August to October in 2010. Then the testing parameter is compared with that of the typical meteorological year. The result shows that the meteorological parameter of the typical meteorological year coincides with the actual measuring- meteorological parameter and the error is just 7.4%.The unfavorable weather days of the typical meteorological year are analyzed and the range of the steady-operation of the ASHP-SWHS is confirmed, the hot-water temperature from November to February is set for 50℃and 55℃in other months, the opening time of air-source heat pump unit at 16:00. The factors that influence the operational performance of the solar water heating system unit and air-source heat pump unit are researched and the mathematical model for performance research and experiment test methods are given. The power consumption of ASHP-SWHS in different months of typical-weather year is calculated by theoretical analog computation in the area of Xi'an, and then the conception of low carbon (LC) is introduced for estimating the LC performance of ASHP-SWHS. The research demonstrates that the power consumption of the ASHP-SWHS is very little, and it is not only good at energy conservation but also environmental protection. The ASHP-SWHS is applicable for popularizing and using.