The Study On The Operation Strategy Of The Solar Assisted Water Source Heat Pump Space Heating System

In recent years,China's urbanization has developed rapidly,and rapid urbanization has driven the sustainable development of the construction industry.The scale of China's construction industry has continuously expanded,and the construction area has increased substantially.This has led to a large amount of energy consumption,and the energy consumption of heating systems in northern cities in building energy consumption.The intensity has been relatively large,how to save the energy used by heating in northern towns,and how to increase the proportion of renewable energy in heating in northern towns has always been the focus of domestic scholars.Solar-water source heat pump space heating systems are attracting more and more attention as a system for heating using renewable energy.How to increase the heating efficiency of solar-water source heat pump has become the focus of many scholars.First a simulation model of the solar assisted water source heat pump space heating system with multiple operating modes is established using TRNSYS software.And the simulation model is validated by the operating data of a similar projects in Liaoning Fuxin.Secondly the efficiency of the four operation modes are analyzed,An improved operation strategy was proposed for the solar-assisted water source heat pump space heating system.The simulation model of the solar-assisted water source heat pump space heating system was used to analyze the optimization of the operation strategy in different regions,and the average COP of the system during heating period can be increased by 5.86% to 43.89%.As the level of local solar energy resources increases,the operation strategy's improving effect on the system decrease.The best value of the key parameters of the improved operation strategy: hot water activation time is found.Then a method to design the volume of the heat storage tank of the solar assisted watersource heat pump space heating system is presented.The space heating load and the solar radiation are considered simultaneously in this method.In order to show the advantage of this design method,TRNSYS software was used to simulate the same solar assisted water-source heat pump space heating system case project with the volume of the heat storage tank designed by both the method brought out in the paper and the one described in the China national design code.Performances of the average system COP of the system designed by the two different methods are investigated and the results show that the solar assisted water-source heat pump space heating system with the heat storage tank volume designed by the method presented in the paper can be increased by 5.7% to 14.4%.Finally,the economical and energy-saving and environmental-friendly benefits of the solar-assisted water-source heat pump heating system are analyzed.Analyzed the initial investment,operating costs and annual cost of the system,compared the water source heat pump heating system and the gas boiler heating system,and it is finally proved that the solar-assisted water-source heat pump heating system has good economic prospects and has a good environmental protection benefit.