| Energy contradiction between supply and demand is intensifying, and the problem of environmental pollution is severely, the task of energy saving and emission reduction of the world is facing a serious challenge. HVAC energy consumption occupies a large proportion in the building; it is also one of the important aspects of environmental pollution, so its energy saving stress coexists with potential. Water source heat pump system can take advantage of the water while achieving cooling and heating requirements, is recognized as a highly efficient and energy saving heat pump air conditioning system. Now, the water source heat pump system is usually use sensible heat that exists in non-clean water as a low quality heat source of heat pump unit. But the water also contains a lot of latent heat, and it has not been used effectively. Thus if this part of the heat is developed, it will be able to alleviate effectively the energy shortage and environmental pollution problems..This article proposed a new heat pump air conditioning system that is non-clean water source heat pump system with collect freezing latent heat. It focuses on the design and development of the key equipment that is freezing heat exchanger in system, the heat transfer performance and system operation performance. Major research works and results are following:(1) When the water temperature is low, it is easy to form ice crystal during the collection freezing heat. The writer developed a new heat exchanger that has deicing rod and chained kind of drive deicing. It is realized that the demand of continuous deicing and excluding ice are satisfied when collecting freezing heat.(2) According to the characteristics of the solidification structure and heat transfer characteristics of the heat exchange tube, heat flow calculation formula is obtained. Simplify the heat exchange tube structure and build the model, the heat exchange process for exchange of heat pipe is simulated, the temperature change of heat exchange tube heat exchange process characteristics is pointed out. The heat exchange tube inlet temperature is simulated as1℃,2℃and3℃respectively at the process of heat transfer. The simulation results show that the higher inlet temperature, the more unfavorable to the freezing heat exchanger collect. To simulate the heat exchange tube inlet velocity are0.5m/s,0.75m/s and lm/s of the heat transfer process, the simulation results show that the bigger inlet velocity, the more unfavorable to the freezing heat exchanger acquisition.(3) In view of an artificial lake in Harbin, select several days in the May, July and October for taking field measurement the water temperature, air temperature, air humidity and wind speed of the lake. According to the measured data, the experience formula of the lake water temperature is corrected, and the water temperature model of small errors for the lake temperature in spring, summer, and heating before is obtained. The lake water temperature’s change rule is predicted through the model, it also provides the basic data for the capacity analysis for lake water source heat pump heating/cooling.(4) The air conditioning system is designed for a building. The air conditioning system adopts the unclean water collecting the freezing heat pump system. According to the design parameters, the system and conventional air conditioning system are compared in the initial investment, annual operating cost and energy consumption. The results show that although the unclean water collecting the freezing heat pump systems in initial investment has no obvious advantage, but in terms of annual operating cost and energy consumption has obvious saving and energy saving advantages.The results from simulation and measured water temperature data in this article has guiding function in some degrees to develop non-clean water source freezing heat collection heat pump system technology. |
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