Design and operation of two-stage air conditioning systems with lake water-source heat pumps

The air conditioning cold source of this project adopts the combination of natural cold source and artificial cold source, making use of the water resource of Qiandao Lake and combining with the four pipe air conditioning system of the hotel. The secondary cooling scheme with double cold sources is adopted in summer and part of the transition season. The water of Qiandao Lake is used as the free cold source for primary auxiliary cooling, which can bear part of the indoor load and most of the outdoor air load. The refrigeration host is used as the secondary cooling source. In winter and part of the transition season, the water of Qiandao Lake is used for direct cooling for the inner area. At the same time, in order to protect the natural landscape resources of Qiandao Lake, the pipe jacking technology is adopted to take water, the water intake is set below 20 m of Qiandao Lake, and the return water at the primary side of the lake is used as the landscape water of the project to save energy.