Analysis Of Solar-ground Coupled Heat Pump System For Heating In Servere Cold Regions

As the development of ground source heat pump technology, it had been usedin a wide range of regions. But the heat load is far greater than cold load in thesevere cold regions, if heat pump operation for a long time will cause temperatureof soil dropping, so that the system cannot run effectively. In order to solve thisproblem, solar energy is used to supply heat to soil. Temperature of soil will keep inbalance when solar energy supply heat to the soil.In this paper, a new system is proposed which use solar-ground source heatpump for spacing heating and domestic hot water on the basis of the previousresearch. The system is divided into five subsystems: the solar heat collectingsystem, the domestic hot water supply system, the floor radiant heating system, U-pipe system and heat pump heating system. In the summer, the solar energy is usedto supply hot water at the same time to the soil for thermal storage, giving priorityto the supply of domestic hot water system. In the winter, solar energy is only usedto preheat the domestic hot water, while the soil source heat pump heating systemfor spacing heating at the same time for domestic hot water heating.A multi-zone civil building was chosen as the research object in the Harbin.The method of counting some parameters which determine the quantity of systemwere introduced. TRNSYS software was used to establish the model of system. Thesystem conducted a one-year simulation by setting the proper control signal. Manyvariables were analyzed according to the simulation results, such as temperature ofroom, the average temperature of soil, temperature of inlet and outlet pipe andtemperature of hot water tank, characteristics of heat pump. The influence of pipe atdifferent spacing and depth to the system performance also been simulated.According to the simulation results, author gives a reasonable space and depth ofburied pipe.Finally, The economic benefits of this system was analyzed between thissystem and traditional heating boiler system. Author obtained that this system hasconsiderable economic benefits, and demonstrates this system was feasibility incold regions. The research of this system laid the theoretical foundation forpractical application.