Application Research Of Household Low Ring Temperature Air Source Heat Pump Heating In Beijing Area

According to the survey data,in 2016,the transformation of coal to clean energy in rural areas of Beijing actually transformed 663 villages and 227 thousand households,of which 151 thousand households were converted to air source heat pump heating in winter.The hot water type low ring air source heat pump unit is mostly used in this air source heat pump unit.The heat pump unit can operate normally at the condition of-20 C in the laboratory.However,the key technology of the hot water type low ring temperature air source heat pump heating system is not comprehensive enough in the rural area of Beijing.Therefore,the selection of the form of the heating end,the energy saving operation of the circulating water pump and the field evaluation method have great research value.In this paper,a quasi low temperature air source heat pump with a quasi two stage compression is theoretically analyzed and simulated with the traditional monopole compressed air source heat pump system.The paper highlights the superiority of the quasi two stage compression system under the low temperature environment.This paper tests the low cycle temperature air source heat pump with quasi two stage compression under low temperature,and tests the adaptability of the heat pump unit at low temperature condition in the enthalpy difference laboratory.In this paper,15 typical cases of hot water type low ring temperature and air source were selected to conduct the field performance test in the heating season,in the rural area of Beijing.The test time was 2017/1/15-2017/3/15,for a total of 60 days.Through the field test of typical cases,the research and analysis of the thesis are as follows:Through the comparative analysis of different heating end-user tests,it is found that typical cases have the old radiator,the new radiator and the floor radiant coil.The average daily temperature in the laboratory is between 16 and 22.1,and the system COP is between 2.05-2.79.For the terminal form of old radiator,new radiator,floor radiant coil users,in the absence of government subsidies,heating costs were 30.64 yuan/square meters,24.88 yuan/square meters,17.65 yuan/square meters.In government subsidies,the heating cost is 24.17 yuan/square meters,20.11 yuan/square meters,13 yuan/square meters.In the conversion of annual cost under the condition of no government subsidies.The annual cost was 30.64 yuan/square meters,25.88 yuan/square meters,21.65 yuan/square meters.In government subsidies,the annual cost was 24.17 yuan/square meters,21 yuan/square meters,17 yuan/square meters,This is of guiding significance for the form selection of the heating end.Through the analysis of energy saving on energy consumption of circulating water pump water pump test:15 typical cases of actual power consumption accounted for 0.05-0.35,EHR(EHR)at 0.030-0.145.The actual value is far beyond the design value,and has great energy saving potential.In the fixed frequency air source heat pump system,the circulating water pump is combined with the heat pump operation mode.In the variable frequency air source heat pump,the circulating water pump is controlled by variable speed according to the water supply temperature difference.The circulating pump energy consumption comparison and analysis calculated by these two methods can significantly reduce the pump power consumption and EHR,and play the role of energy-saving operation.The evaluation index TCOP of the air source heat pump heating system under actual operating conditions is put forward through the field monitoring of typical cases.Taking the test of three typical days instead of the whole heating season test,it is suggested that three typical daily temperature frequencies should be-4,2 and 4,respectively,and their corresponding weight coefficients are 0.20,0.50 and 0.30 respectively.If the relative error of the TCOP value calculated by this method and the actual test COP value is within 5%,it is considered that TCOP is more reasonable.The use of TCOP as the evaluation parameters of the actual operating conditions of the heat pump system can shorten the test time,save the manpower and material resources,and facilitate the comparison and analysis.