Design Method Research Of Ground Source Heat Pump System And Ground Heat Exchanger Parameters Optimization

Ground source heat pump technology is a new technology of energy conservation and utilization of renewable energy. More and more people know it. This technique is also one of the effective methods for energy resources and protecting environment in some countries in the world to solve the energy crisis. At present, one of the hot topics of research on the ground source heat pump technology at home and abroad is the ground source heat pump system in different areas, studying on the applicability of different climatic conditions.This paper contents are as follows:The heat transfer process of heat exchanger Analysis of soil source heat pump system of buried tube heat transfer process, software simulation system provides the theoretical basis for TRNSYS simulation;Using TRNSYS simulation software as a platform, establish the soil source heat pump system model, dynamic analysis of load variation of hourly cooling load of buildings, the building needed. Research systematic design method of soil source heat pump system, and through the test data of practical project, analysis of the operation of the whole system;Using TRNSYS simulation software, research in different climate zones, in cold and hot summer and cold winter climate zone, looking for two typical city of Xi’an and Wuxi, value problems of buried tube heat exchanger in side and out of the water temperatureThe annual cost method, economic analysis, looking for the maximum output, minimum work, most economically reasonable time, buried the corresponding pipe heat exchanger inlet and outlet water temperature limits, improve the efficiency of soil source heat pump systems, optimization and analysis of the system.This topic through theoretical analysis, experimental data and simulation analysis, we draw the following conclusions:Buried pipe underground heat exchanger is a complex process, buried pipe heat exchanger for liquid circulation in the soil is an unsteady heat transfer process, formula of the temperature of a node is derived in the regenerator; Through rock-soil thermal response test, the higher initial temperature of soil in Shanghai and Wuxi area, and initial soil temperature Xi’an area low; In the Shanghai and Wuxi area, because of the imbalance of the building cooling load, cooling load in summer is far greater than the heat load in winter, so it needs to add auxiliary heat source—cooling tower, to promise the balance of suction and emission heat;In cold climate, Xi’an, the comparative analysis of different buried pipe limited import and export water temperature of heat exchanger, through the analysis of energy consumption and economy, the annual cost is the best temperature limits. So, in a cold climate, the best inlet temperature in winter conditions of buried tube heat exchanger should be above5℃, and summer conditions of buried tube heat exchanger outlet temperature is below32℃;In the hot summer and cold winter climate zone of Wuxi City, the unit output and maximum annual cost optimum temperature heat exchanger outlet should be below31℃minimum corresponding summer condition of buried pipe, and winter conditions of buried pipe imports suitable temperature is in4.5℃above heat exchanger.