Research On The Technology Of Dual Cryogenic Source Heat Pump And Solar Complementary Heating For Residential Buildings In Northern Villages

There is a great potential for cleaning heating in the northern villages.Based on this,the existing heating methods and problems of the typical rural houses were analyzed in the north.Considering the advantages of sufficient electricity and abundant solar energy resources in Shandong Province,the research which aimed at complementary heating technology of electric drive heat pump and solar energy was carried out.In this paper,a dual cryogenic source heat pump combined with solar complementary heating system which integrated with refrigeration,heating and hot water supply,is put forward(the system has been declared and approved for national invention patents).The system mainly includes a dual-cryogenic source heat pump unit,a heat collection system and a user-side device.The two evaporators,which are the air source evaporator and the water source evaporator,were arranged in parallel of the heat pump unit,and the system can be converted to different working conditions by switching valves.Taking the typical farmhouse in Jinan,Shandong Province as a background,the principle and control strategy of dual cryogenic heat pump combined with solar energy complementary heating system are expounded,and two kinds of hot water supply modes are put forward.In addition,the system model was established,using by TRNSYS which can simulate the heating water and heating modes of a typical farmhouse.The results show that the performance of the system is significantly higher than other traditional systems.In order to study the heating effect of the system,simulations were performed from the typical winter days of early winter and early spring,mid-winter,to deep winter respectively.The results showed that all three operating strategies surpass 43°C in water supply temperature,which can reach 60 ? at the top.Compared with the mid-winter standard day heating mode,the power consumption of the deep winter standard day heating mode decreased to 17.7%.Analyzing and comparing the coldest source of dual cryogenic source heat pump combined with solar heating system with the air source heat pump heating system,it can be found that the complementary heating system consumes less power and the heating effect can be ensuredmore.The optimization of the heating system was studied.In order to achieve the optimal value of system economics,two influencing factors,which are the size of the solar collector and the volume of the storage tank,were used to optimizing the design of the system.The relationship between the collection area ratio of heating season and the air-conditioning load rate was analyzed.Considering power consumption,COP,heating effect and using economic evaluation to determine the optimum collector area,it was determined that the volume of the heat storage tank was 70-80 L/? and the ratio of heat collection area was 12% in the final.In this condition,the economical and technical optimization of the dual cryogenic source heat pump combined with solar heating system can be achieved.The research of the electric-driven heat pump combined with solar energy heating technology and its optimized configuration scheme have theoretical and practical value for the reconstruction of clean heating of buildings in northern villages.