Research On The Coupling Characteristics Of Composite Ground-Coupled Heat Pump With A Cooling Tower

In recent years, the energy problems have attracted more and more attentions, the non renewable of traditional energy sources will limit the development of society. Ground source heat pump has the characteristics of sustainable development and environmental protection, so it get a fast research. Particularly using the composite ground-coupled heat pump with a cooling tower can solve the soil thermal imbalance, improve the work efficiency and reduce the initial investment.We need make design schemes and control strategy based on the actual situation of composite ground coupled heat pump system, ensure the operation condition of the composite heat pump is best, and its coupling degree with the cooling tower is high. Combined with the climate characteristics of Zhengzhou, we make some researches as follows :(1) Introducing the research background and status of the composite ground-coupled heat pump, analysis the advantages and disadvantages of parallel connection and series structure of the composite system,.summarized the basic method of selecting a cooling tower.(2) Establishing the model of the compressor, condenser, throttle valve and evaporator and simulating the refrigeration efficiency of heat pump in different working conditions. According to the collected sample parameters, calculate the change curve and formula of the COP correction coefficient, and COP is affected by the condensation temperature, its variation range is about 2.17% ~ 3.05% /℃.(3)By using classical thermal enthalpy balance theory, calculating the prediction method and influencing factors of the outlet temperature of the cooling to tower. Analyzed its fitting formula to make the contronl strategies.(4)Combined with the annual hourly temperature in Zhengzhouto calculate the annual load of a building, according to the winter heat load to set length of buried pipe system, cooling tower should meet the highest demand of cold load in summer, to ensure the thermal balance of underground heat exchange system in the whole year. By analysising the pump’s structure and operational principle,make the control strategies such as controlling the range of temperature and predicting cooling tower‘s effluent temperature to improve the work efficiency,make the soil thermal imblance.