Study On The Solar And Ground Coupled Heat Pump Heating System

Ground-source heat pump system has the advantages such as clean, efficient and energy-saving. However, its disadvantage is the imbalance of underground temperature field is caused by the imbalance of load in different seasons during the long-time running.Meanwhile, solar energy system with huge reserves and clean utilization has some shortcomings such as low energy density and intermittent. On the basis of the combination of the advantages and disadvantages of the two systems, the solar-ground coupled heat pump system which is suitable for the northern region climate is proposed and analyzed, and the proposed ground-source heat pump system is installed at Shandong Beyond Ground-source Heat Pump Technology Limited Company.The literatures have been reviewed on the development and application of ground-source heat pump based on solar energy, and the research status of this technology has been analyzed. On the basis of previous work, solar energy and ground-source coupling heat pump heating system is determined to the design referencing to the actual working condition of indoor floor radiant heating engineering and outdoor ground-source heat pump engineering in the factory dormitory building.The solar energy and ground source coupled heat pump system is used to solve the problem of imbalance of underground temperature field during the long-time running. The solar assurance f’ could be calculated by the equal between extracting heat from the ground temperature field in heating season and recharging heat to the underground in other season. Then, the solar system collector area, the size of the storage tank, the pump type in the solar side, and volume of expansion tank etc. are calculated. The priority in use of heat collected by solar collector is guaranteed by setting the reasonable control mode.The model of solar caoupled ground-heat pump system is developed by using Trnsys software and the system heating performance is simulated dynamically. The effects of main parameters are analyzed such as outdoor temperature, indoor temperature, outdoor solar radiation, the return water temperature of water storage tank and the heating load of ground-source heat pump system and the solar system on the heating performances in the entire heating season, respectively. Moreover, the solar energy-ground source heat pump coupling heating scheme is verified. Simulation results show that the heat provided by solar section is about36%for heating load of the whole system during the heating season. It is of great significance for the recovery of underground temperature field of ground-source heat pump system in heating season and the improvement of COP value. The research can provide the basis to solve the underground temperature field imbalance problem in building heating and ground-source heat pump system in this paper.