| Today,with the rapid development of the world automobile industry,the problems of exhaust pollution and energy crisis brought by traditional fuel vehicles are becoming more and more serious.New energy vehicles have become the main development direction of the world automobile industry.Since the current mainstream new energy vehicles such as Battery Electric Vehicle still have problems such as high cost and battery pollution,it is imperative to develop a new type of new energy vehicle represented by Compressed Air Vehicle(CAV).The operation of CAV relies on Compressed Air Engine(CAE)to provide continuous and stable power.CAE can be analogized to the "heart" of a car.CAE's function is to convert the pressure energy of high-pressure air into mechanical energy to drive the car.In this paper,the four-stroke CAE obtained by a gasoline engine modification design is the main research object.The combination of theory,simulation and experiment is used to analyze and research CAE system(CAE,main gas supply system,branched gas supply system and electronic control system)and CAV sample.The purpose of analysis and research is to verify the operational feasibility of CAE and CAV and to obtain relevant laws affecting their performance.Firstly,a 1.2L naturally aspirated four-stroke gasoline engine was modified to obtain a cylinder direct injection four-stroke CAE.Based on the theoretical analysis,the CAE was used as the research object,and a complete four-stroke CAE simulation model was established by using GT-Power software.By analyzing the simulation results,the influence laws of the main initial parameters of CAE on its working characteristics was obtained.In addition,the comparison of the bench test and the GT-Power simulation of the cylinder pressure curve can verify the correctness of the simulation model.Secondly,based on the working characteristics of the four-stroke CAE,the air-pressure control distribution system was designed,and the pneumatic components were selected to build a complete and feasible air-pressure control distribution table.The significance of this research is to build a gas supply test platform with the distribution platform as the core.The gas supply test aims to obtain the appropriate CAE gas supply parameter setting range,debug the optimal gas supply system,and ensure the smooth progress of the CAE bench test.In addition,by analyzing the flow characteristics of the internal pipeline of the air-pressure control distribution system,the laws of the flow characteristics of the piping system and its pneumatic flow components were obtained.Thirdly,based on the structure and principle of the four-stroke CAE and air-pressure control distribution table,four different types of nozzle structures were designed,and the internal flow field of different nozzles was simulated and analyzed by CFD technology.By comparing and analyzing the simulation results,the optimal nozzle structure design scheme was obtained,which effectively improves the gas supply efficiency of the CAE gas supply system.Finally,based on the related research of four-stroke CAE,air-pressure control distribution system and high-pressure nozzles,the gas supply test platform was built to test and obtained the matching parameters of the suitable CAE gas supply system.Based on this,the CAE bench test was carried out.Through the comparative analysis of the bench test and the simulation results,the feasibility of the four-stroke CAE was verified,and the regular conclusions related to the CAE working characteristics were obtained,and there is certain guiding significance for the in-depth study of the future CAE field.In addition,based on the theoretical analysis of the feasibility of CAV,after the completion of the bench test,CAE was loaded on the CAV prototype for vehicle testing,and the feasibility of CAV was verified by the test.According to the test data,three air-powered vehicles loaded with different CAEs were compared and analyzed,which provided ideas for the optimization and improvement of the CAV prototype. |
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