Performance Research And Structural Optimization Of Gas-Liquid Ejectors

With the accelerated industrialisation of China,the consumption of energy is also increasing and the problem of energy shortage is becoming more and more prominent.As a result,various energy saving measures are being developed worldwide and various energy saving technologies are being developed.It is well known that heat exchangers,as equipment widely used in various sectors,play a very important role in the transformation of energy-saving technologies.And improving the efficiency of these heat exchangers is a key issue in reducing energy consumption.Injectors,a common type of heat exchange equipment in industry,are studied in this thesis with the aim of improving their efficiency.This thesis discusses the current research status of gas-liquid injectors and the working principle of gas-liquid injectors in the gas-liquid mixing process,and briefly introduces the basic calculation methods and processes in numerical simulations.In order to improve the efficiency of the injector,this paper uses numerical simulation to study the law of change of the flow field in the injector and to analyse the mechanism of action of the flow field in the injector,in order to achieve effective regulation of the flow field in the injector,so as to achieve the purpose of improving the mixing effect of the injector.In order to improve the efficiency of the injector,this thesis considers the influence of structural dimensions and inlet and outlet pressure drops on the performance of the injector,carries out simulation calculations of the mixing state of the two fluids in the gas-liquid injector,carries out specific studies on the nature of the distribution diagrams of the pressure and flow velocity of the two fluid phases in the mixing environment,and carries out a comparison of the characteristics of injector structures with different gas-liquid flow ratios,throat lengths and throat diameters.In addition,sensitivity analysis and multi-objective optimisation of the injector structure parameters were carried out using the diameter and length of the injector throat as target parameters.The results show that the amplitude parameter has a significant influence on the pressure drop and efficiency,with sensitivities of 60.259% and 60.972% respectively.Three sets of optimised structures were obtained by iterative calculation using the average pressure drop and efficiency in the calculation domain of the hybrid chamber as the optimisation objectives.Compared with the original structure,the optimized structure reduced the pressure drop in the computational domain of the throat by 14.45% on average and increased the efficiency by 24.25%on average.Based on the traditional gas-liquid injector,a new gas-liquid injector structure has been introduced which increases the efficiency of the injector without affecting the velocity and pressure fields within the mixing chamber and the pressure drop at the inlet and outlet.This new gas-liquid injector structure provides some guidance for the design theory of the injector structure,as the efficiency of the new gas-liquid injector is increased by an average of 16.373%compared to the conventional structure.