Irreversible Thermodynamics Loss Analysis Of Two-stage Ejector Refrigeration System

As the energy shortage and the environmental pollution problem increasingly prominent,to improve energy utilization rate from the perspective of energy conservation,and thus improve the energy-using environment appears increasingly important.In the ejector refrigeration system,vacuum facility and chemical production,ejector has become more widely applied.Through the adoption of irreversible thermodynamics in the principle of entropy production and exergy analysis,which expands the application of ejector to the actual irreversible cycle process of refrigeration system,such as heat transfer,mass transfer,diffusion process and so on.This article based on the theory of thermodynamics to intensive study the irreversible loss of two-stage refrigeration system,entropy equilibrium and entropy production equation of two-stage refrigeration system is deduced according to the theorem of momentum,mass and energy conservation equation,analyses the internal fluid flow process of entropy production and exergy losses division of each component in the two-stage ejector refrigeration.Entropy can be used to describe the transformation of quantity,direction and irreversibility for the existing forms of movement in the nature.In this paper,based on the analysis of the first law and second law of thermodynamics,the relation is mainly focused on the research and progress of the two-stage tandem ejector refrigeration system,the development trend and application prospect of entropy analysis method are stress emphasized in the ejector,and the variation trend of the entrainment ratio,the performance coefficient and the mechanical performance coefficient in refrigeration system with several different kind of refrigerants are studied and compared at different generation temperature,evaporation temperature and condensation temperature.Analyze the irreversible loss distribution regularity of each of component in ejector refrigeration system,at the same time operation parameters influence on each part of the system entropy production are also analyzed,which can accurately determined the operation parameters to ensure a better system performance coefficient and satisfy the total entropy production minimum simultaneously,that is to say,in the optimum condition of system performance.Thermodynamic system involves heat and energy conversion process,based on the entropy production and exergy losses analysis method of thermodynamic system in the application of ejector refrigeration system has been gradually studied by several scholars at home and abroad.Those methods compared to the traditional design method which employed on three conservation equations(quality,energy and momentum)of the thermodynamics first law,this kind of method is put forward in the energy loss analysis of each component in the ejector refrigeration system can be more comprehensive and objective.To grasp the research method and theory analysis of ejector refrigeration technology,which can promote the development of emerging technology on ejector refrigeration field,towards its to a wider range of practical applications by laying a solid theoretical basis.How to select the appropriate refrigerants is a significant method to improve the performance of two-stage ejector refrigeration system,as the energy excessive consumption and increasing shortages gradually aroused people's attention,using low grade heat source as a power driven way of ejector refrigeration field,will be further researched and applied,in this paper,the related research points out the direction for the performance optimizing in novel two stage ejector refrigeration system.