Effect Of Inlet Air Enthalpy Of Evaporative Condenser On System Performance

With the improvement of people's living standards,refrigeration technology has been widely used in various fields of human life.Application of refrigeration technology is accompanied by the consumption of a large amount of power resources.China's power resources are scarce.so the energy-saving requirements for refrigeration technology are getting higher and higher.Therefore,the utilization of low-grade heat sources such as natural cold sources and waste heat to develop high-performance low-energy refrigeration systems is an urgent need.As one of the four major components of refrigeration system,the condenser's heat transfer performance directly affects the performance of the refrigeration system and operation economics.Temperature of cooling water of the evaporative condenser affects the level of the condensing pressure of refrigeration system,which in turn affects the energy saving of entire refrigeration system.Therefore,this paper focuses on how to effectively use the potential energy in external unsaturated air,as well as solar energy and the low-grade heat source discharged from superheated refrigerant vapor,to reduce the inlet air enthalpy of the evaporative condenser and reduce the cooling water temperature.Thereby reducing the cooling water temperature will lead to the decrease of condensing temperature and condensing pressure,and the increase of refrigeration system COP,making refrigeration system more energy efficient.In this paper,through the analysis of the factors affecting the heat transfer during the steady operation of the evaporative condenser,three schemes for reducing the inlet air enthalpy of the evaporative condenser are obtained:(1)Indirect evaporative cooling is used to reduce the inlet air enthalpy.(2)While using indirect evaporative cooling,the inlet air is dehumidified by the waste heat coming from superheated vapor.(3)While using indirect evaporative cooling,the imported air is dehumidified by solar energy.This paper also conducted a comparative experiment on different methods for reducing the inlet air enthalpy.Experimental results show that the average COP of the system in indirect cooling is 2.69%higher than that of direct cooling.The system has the highest COP in the "cooling dehulidification and then cooling" mode,which is 4.26%higher than indirect cooling and 7.07%higher than direct cooling.