The Numerical Simulation Of The Variable Load Condition Of Ground Source Heat Pump System

Ground source heat pump system consists of three parts, ground heat exchanger system, heat pump units and air conditioning system in the building. Ground heat exchanger is a key component of the ground source heat pump system, the actual operating characteristics of the Ground heat exchanger have a direct impact on the performance of the heat pump system. Building load changes also lead to the change of performance of the heat pump system. Therefore, the three parts are interactional. Actual operating characteristics of the underground heat exchanger have an important impact on the soil heat storage. Therefore, only until ground source heat pump system is running coupled dynamic analysis with building load, the actual operating conditions of ground heat exchanger as well as distribution of soil temperature underground pipes regional can be really understand.By analysis of the different functions of buildings, this paper establishes the building dynamic load model. According to the feature of current buildings with higher floor area ratio, less of buried land area. Most of ground source heat pump works with a single U-tube, double U-tube ground heat exchanger. The three-dimensional numerical model of the single double U-tube and the tube group of underground pipe heat exchanger were established in this paper. Analysis of under different groundwater flow velocity and water content in soil, changes in parameters such as heat transfer, hourly water temperature and soil temperature distribution.In this paper, building dynamic load model combined with underground pipe heat exchanger model and to establish the dynamic model of the ground source heat pump system. According to this model, analyzed the unit performance of office building and shopping malls built on the different modes of operation, analyzed the temperature distribution around the underground pipe heat exchanger. Analyzed under intermittent operating conditions the heat transfer of geothermal heat exchangers and restore law of temperature distribution around the underground pipe heat exchanger. The simulation results have some reference value on future similar projects.