Study On COP And Benefit Of Condensing Heat Recovery System

In order to solve the problems of the energy waste and the environmental pollution attributed caused by the separately setting up air conditioning system and hot water system,the condensation heat recovery technology is proposed.This technology can provide free hot water by recovering the condensation heat while the air conditioning system cools.In order to investigate the operation performance and benefit of the condensation heat recovery system,in this paper,the operation performance of the air conditioning system with chiller plants and the total heat recovery system is numerically studied by taking a printing factory project in Shijiazhuang City as an example.Firstly,the cooling and heating load of the factory building is simulated by using the De ST energy simulation software.According to the load characteristics of the building and printing equipment,the results show that the project has potential of the condensation heat recovery.On basis of the theory of the condensation heat recovery technology,an indirect condensation heat recovery system adopting plate heat exchangers is designed,and the main equipment of heat recovery system in refrigeration and total heat recovery mode are selected.Secondly,the simulation models of the air conditioning system with chiller plants and the total heat recovery system are built by using the TRNSYS software.and the operation performances of the two systems are calculated respectively under three conditions: cooling equipment all year around,cooling buildings in the cooling season,and then cooling equipment all year around and cooling buildings in the cooling season.Besides,the parameter variations of the temperature,power and coefficient of performance are analyzed during the simulation time,and the average coefficient of performance and cooling energy consumption of the two systems are compared.In addition,the effects of the variation in the outlet temperature of the chilled water and hot water on the coefficient of performance,the energy consumption and the hot water output are simulated and evaluated.Thirdly,this study compares the economy,the energy saving and the environmental benefits of the total heat recovery system under three conditions with different hot water outlet temperature.The results indicate that the dynamic payback period of the total heat recovery system is short,and then its energy-saving benefits is high.Moreover,the emissions of the carbon dioxide,the sulfur dioxide and the dust of the total heat recovery system are reduced.In the total heat recovery system,the fluctuation of the cooling load is smaller,the system operation is more stable,and the energy-saving benefit is higher.According to the research,the total heat recovery system,which adopts the plate heat exchanger to indirectly recover condensation heat to heat the tap water,has the dual benefits of increasing energy efficiency and lowering environmental pollution.This study verifies the feasibility and economy of the total heat recovery system in practical engineering applications,provides reference value for the future applications,and possesses certain guiding significance.