Study On Energy Efficiency About Lake Water Heat Pump Systems In ChangJiang Drainage Area

In this paper, the domestic and overseas research progress of Surface Water Source Heat Pump (SWHP) is reviewed, thus the advantage, disadvantage and utilizing limitation of this air conditioning type is analyzed and summarized. SWHP has a wide utilizing prospect and value in Yangtze River District, where the SWHP systems using static water, such as lake water, have been put into action. Most of these systems are open systems. As the limitation of theoretical knowledge and practical experience, the bad performance of these systems in energy saving respect turns out. This is caused by two major reasons, the recognition shortage of lake water temperature distribution and the LWHP water intake system.The water intake selection rule of open type SWHP system is preliminarily summarized in this paper, while the detailed quota system of water intake selection plan is built up as well. Moreover, Analytic Hierarchy Process (AHP) of model optimization is introduced and used in order to optimize the water intake selection plan in practical program, and in the end proof the preciseness of quota system and analysis approach.The energy efficiency model under partial load performance is figured out for the components of open type LWHP system, namely, heat pump main unit, water source side pump, load side pump and terminal equipment. During the model building process, the influence of water intake selection is focused on, while the similarities and dissimilarities of open type LWHP system and prevailing air conditioning system with cooling towel are compared in the aspect of energy consumption. By comparison, the two systems are mainly different in the energy consumption of water source side water intake system and cooling water system.Considering the model calculating data and the energy consumption influence of different water intake selection plans, the essential condition that open type LWHP system reaching its energy saving goal is worked out in the paper, when compared to prevail air conditioning system. The essential condition is the equation that concerning water source water intake energy consumption and water temperature, cooling system energy consumption and water temperature. At the same time, relative energy saving rate of open type LWHP system is worked out related to prevail air conditioning system.