Study On Intermittent Operation Of Hybrid Ground-source Heat Pump System For The Hotel Buildings

Heat transfer process of the underground heat exchanger of ground source heat pump system with the surrounding soil is non-steady-state,soil temperature will constant chang with the unit running, remove and the release of the heat. In the region with hot summer and cold winter, summer accumulated row heat is much larger than the winter accumulated take heat,the running of the heat pump unit of the hotel buildings continuously sustained exothermic to the soil, will cause the circulating water temperature of the underground heat exchanger be improved and unit operating conditions deteriorated. If you give the soil some recovery time, make the heat pump unit working in a good running condition will improve plant operation efficiency and reduce operating costs. Therefore, we propose the intermittent run program of the ground source heat pump system for hotel buildings.A hotel in Wuhan, for example, we use DEST software to calculate the annual dynamic load of the hotel and design the ground source heat pump system of the hotel, use the TRNSYS software establish the ground source heat pump model. First make two decades simulated of continuous operation conditions, analysis of Wuhan ground source heat pump heat accumulation. Then according to the load characteristics of hotel buildings,design three intermittent operating conditions, make two decades simulated of the conditions,analysis of soil temperature field in the intermittent operating conditions as well as the energy consumption of the system. The last,compare the effect of heat transfer,changes in soil temperature field and the energy consumption of the hybrid ground source heat pump system in continuous operating conditions and intermittent operation conditions. And through a comparative analysis to determine a better intermittent operating conditions that both soil temperature restore beneficial but also saves more energy consumption. The simulation results show that:the intermittent operation of hybrid ground source heat pump can really alleviate soil heat accumulation problem. Intermittent operating conditions3for hotel buildings of Wuhan area is more efficient, intermittent operating conditions3’s payback period is3years.In order to achieve intermittent operation of the hybrid ground source heat pump system, an extra cooling tower is chosen, whose capacity was equal to the heat exchanger, when the heat exchanger did not work, you can run the cooling tower to meet the requirements of heat pump system for cooling,in order to effectively solve the heat accumulation in soil, and makesure the heat transfer capability of ground heat exchanger be recoveried.The results from this study have some reference value in practical engineering.