Study On The Performance Of Wide Channel Plate Exchanger Of Reclaimed Water Source Heat Pump

With the increasingly prominent energy and environmental problems,energy conservation and emission reduction have become the main content of the energy strategy development of all countries in the world.At present,the utilization of renewable energy has become one of the dominating study and technology promotion directions of energy-saving and emission reduction measures.As an energy saving and environmental protection technology,reclaimed water source heat pump has gradually become a research topic in the field of HVAC in recent years.However,due to the restriction of some key technologies,the proportion of practical application of reclaimed water source heat pump technology in the field of HVAC is still small.It is of practical significance for the reuse of water resources and the sustainable development of economy and society to clarify the problems existing in the practical application of reclaimed water source heat pump technology and put forward effective methods to solve the problems.Through to xi’an a reclaimed water source heat pump heating system a field test of the heating season,it is found that wide channel plate exchanger in the process of heat transfer,due to the special quality of reclaimed water,can produce microbial dirt quickly within the heat exchanger,dirt adhere to the surface of the heat exchanger can reduce the heat transfer performance of heat exchanger,congestion,serious when can appear even heat exchanger heat pump host the phenomenon such as downtime.Based on the field test,the main causes of the attenuation of the heat transfer performance of the plate heat exchanger with wide runner are analyzed.Based on the principle of energy conservation and mass conservation,the numerical simulation of two kinds of plate-type heat exchangers with wide flow passages was carried out by using the distributed parameter method.The effects of microbial fouling on the performance of heat exchangers were analyzed and discussed.The results show that the heat transfer performance of the wide channel plate heat exchanger is different with different channel arrangement.The influence of velocity and inlet temperature on the reclaimed water side and the intermediate water side should be considered in the choice of different channel layout.Reclaimed water inlet temperature of 18℃,intermediate water inlet temperature 8℃,reclaimed water flow is 70 m~3/h,the intermediate water flow is 80 m~3/h,with the accumulation of dirt,heat exchanger heat transfer performance degradation,when microbial dirt accumulation balance,the heat transfer coefficient of single-channel series(1#)heat exchanger decreased by 31.3%and the efficiency value decreased by 5%,while the heat transfer coefficient of double-channel series(3#)heat exchanger decreased by 19.2%and the efficiency value decreased by 3.88%,indicating that microbial fouling had a great influence on the heat transfer of single-channel series(1#)heat exchanger.Therefore,it is a favorable way to improve the performance of wide channel plate heat exchanger to reduce fouling accumulation and choose proper channel layout.