Study On Control Strategies For Cooling Tower Of Hybrid Ground-source Heat Pump Systems For Hotel Buildings

Ground-source heat pump system had been more and more widely used on account of energy saving, environmental protection, efficient, and hybrid ground-source heat pump Systems with ground heat exchanger and cooling tower had been adopted more in wuhan as a typical city with a hot summer and a cold winter.Matching operation on ground heat exchanger and cooling tower had became a difficulty of hybrid ground-source heat pump Systems. Cooling tower opened too much, cooling loop will consume large amounts of energy. Cooling tower opened too little, the inlet fluid temperature of heat pump and soil temperature will be very high, leading to the decrease of the heat pump performance, also cause the increase of energy consumption. However, when to open the cooling tower is also one of the keys. How to control the cooling tower has became a very worth studying problem, which enables the system to long-term efficient operation.In this study, a model of hybrid ground-source heat pump Systems had been built inTrnsys platform for a hotel building in wuhan. The author selected multi-control point for the highest temperature control strategy and the temperature difference control strategy respectively, and had simulated for twenty years, Obtained the optimal control points under the four strategies respectively. The optimal control points of the four strategies has been analysand, the results showed that when the highest temperature control strategy was adopted, it’s better to control the inlet fluid temperature of the heat pump; And when temperature difference control strategy was adopted, it’s better to control the outlet fluid temperature of the heat pump.The author puts forward a new control strategy on the study conclusion, using the highest temperature control with the inlet fluid temperature of the heat pump and the temperature difference control with the outlet fluid temperature of the heat pump. And then, the author selected twenty-five control points in the simulation, find the optimal control point of the new contol strategy.