Research On High-efficiency Expansion Technology Of Finite Volume High-pressure Gas Source

With the destruction of the ecological environment and fossil energy depletion,the development of new energy is imminent.The compressed air is green energy and suitable for automobile.Due to the ultra-high pressure storage of compressed air,highy effcient automotive power system is needed,which directly determine the applicability of air-powered vehicles(APV).Based on the theory of finite volume decompression,the key technology of high pressure gas expansion was researched.By theoretical analysis and software simulation.The high pressure pneumatic power system was designed.The whole thesis consists of the following chapters:Firstly,advantages of APV were summarized.The research status of APV and high-efficiency decompression technologies were introduced.The significance of the high-pressure automotive power system based on finite volume decompression method was presented.The main research work of this paper was put forward.Secondly,with the design requirements of the air-powered engine(APE),the working principle of the high-pressure multi-stage engine was explained.The working process of the engine was analyzed and the high pressure power system was completed.Based on the low pressure APE,the structure of the two-stage high pressure APE were proposed.The structural parameters and control parameters of the two-stage engine were determined and calculated.According to the structure of two-stage pneumatic engine,the mathematic model was established by thermodynamics and mechanical dynamics.Then the dynamic simulation was programmed on Matlab.The decompression and working procession of two-stage engine was analyzed.Comparing the two-stage engine and the single-stage engine,two-stage engine are more efficiency.The influence of the control parameters and the structural parameters on the engine's efficiency was discussed.Thirdly,for the pressure reduction with engine control requirements,high-pressure pneumatic solenoid valve was designed.In order to meet requirements of flow,the structure of valve was designed.According to the working frequency and control requirements,the parameters of the solenoid was completed.Based on the principle of electromagnetism and the allowable temperature rise of the coil.The structure of the excitation coil was designed.Used of electromagnetism,thermodynamics,fluid mechanics principle,the mathematical model of high-pressure pneumatic solenoid valve was built.According to computer simulation on Matlab,the movement process,the transformation of air pressure and the current were analyzed.The influence of various control parameters and structural parameters on the dynamic response of the solenoid valve was discussed.Then the structure of the solenoid valve was optimized by genetic algorithm.Finally,the research work of this thesis is summarized and the perspectives on the future are presented.