Numerical Simulation And Experimental Research Of The Performance Of Liquid-Vapor Ejector For Heating System

With the rapid development of China’s economy and the enhancement of green ecological awareness.Energy conservation and environmental protection has become a problem that can not be ignored.The climate in China is diverse,the area requiring heating is large,heating time is long,and energy consumption is large.Therefore,energy saving of heating system has become one of the focus issues in the field of energy supply.As a fluid mixing device with simple structure,reliable operation,good sealing performance and suitable for high temperature operation,ejector is used to reduce backwater temperature in heating system and plays a very important role in heating and energy saving system.In this paper,based on the ejector of liquid ejecting vapor body,theoretical and experimental studies have been carried out.The follows are the main works:(1)Introduced the structure,function and working principle of ejector.Summarized the research progress of ejector in theoretical derivation,numerical calculation and experiment at home and abroad.(2)Determining the structure of ejector is the basis of studying ejector work.Based on hydrodynamics and conservation equation,the basic performance equation of liquid vapor ejector is deduced through theoretical analysis and calculation.And the structure size of ejector is determined according to the equation.(3)On the basis of determining the structure of the ejector,in order to obtain the influence of the working fluid parameters on the vaporization inside the ejector and the state of the ejector end,the vaporization inside the ejector and the change of the state at the entrance of the ejector at different working fluid parameters are observed and analyzed by means of the numerical simulation method of Computational Fluid Dynamics(CFD).And the images under different conditions are obtained.Relevant results were obtained through analysis and integration.(4)In order to verify the accuracy of numerical simulation,an ejector experimental platform in heating and energy saving system was built.By changing different experimental parameters,observing and recording data of each group,and finally sorting out data,the variation of vacuum degree of ejector with working fluid pressure,temperature and flow rate was analyzed.Compared with numerical analysis,the correctness of numerical simulation was verified.The study of liquid-vapor ejector in this paper will provide theoretical guidance and reference for the actual operation of ejector in heating and energy saving system,promote the application of new building heating system,provide new methods for energy saving and environmental protection,and contribute to the sustainable development of low-carbon society.