Application Study On Lake Water Source Pump In Hot Summer And Warm Winter Area

Ground source heat pump technology as an effective energy-saving new technology to reduce building energy consumption that has been widely used in China hot summer and cold winter areas of China. Surface water source heat pump is one of the ground source heat pump in the form and the application research is paid much attention. As we all known, water resource is richer in winter and hot summer and warm winter area, which has an advantage over the former to utilize and promote surface water source heat pump technology. However, there is no heating demand in this area and it leads to less application research of surface water source heat pump. In this paper a practical project case of lake-water source heat pump air-conditioning system is taken as the research object in Yangjiang. Based on theoretical analysis, numerical methods and field test, the application feasibility and effects are analyzed in this paper.Firstly, the mathematical model of water temperature which is affected by the climate parameters is established. Besides, by means of comparing the lake measured temperature with the simulation of water temperature, it is concluded that the difference is not more than 0.8℃, which verifies the rationality of the model and provides a basis for reference in the place of missing hydrological measured data to design the water source heat pump systems.Secondly, from the economic benefits, environmental benefits and energy efficiency, the superiority of lake water source heat pump system over common water chiller air conditioning system applied to the project is analyzed. Furthermore, it is simulated and calculated that the water whose temperature is rising after going though heat exchanger, is released into lake to cause less than 0.35% surface area of the lake water temperature affected. Besides the drain has no effect on water temperature around the inlet,which can prove that it is feasible to apply the lake water source heat pump technology application adequately in hot summer and warm winter area.Thirdly, the hourly air conditioning load is simulated for the actual project. Moreover, the annual cold and heat load of the frequency distribution is presented. Based on the frequency distribution, the capacity and the number of the heat pump air conditioning units is selected, as well as the best running strategy is set out in the whole year.Finally, the heat pump and pump energy consumption model is established respectively and the hourly power consumption of each equipment is obtained. In addition, the hourly COP of the lake water source heat pump units in the actual operation situation for the whole year varying with the cooling water inlet temperature and different loading rates is calculated by means of analog simulation. Moreover, by comparing the EER(energy efficiency ratio) for cold source side of the lake water source heat pump system with the common water chiller air conditioning system with cooling tower air conditioning system at refrigerate condition in summer, it comes to a conclusion that the EER of LWSHP system is 4.63 and the other system is 2.91 as well as the former relative to the latter in the summer of energy-saving rate is as high as 36%, which provides the further evidence of the energy saving effect of water source heat pump system.