| Energy shortage has become a common concern of all countries in the world.The internal combustion engine is a kind of energy consuming machine with high thermal efficiency,its thermal efficiency is only about 40%.Therefore,it is very important to study the recovery and utilization technology of engine waste heat.In terms of the problem of mismatch between the temperature of the exhaust gas of the internal combustion engine and the high-efficiency temperature range of the post-processor,and the problem of insufficiency of inlet response under transient loading condition of turbocharged system,in this paper,the overall scheme of the waste heat recovery is presented.The key technologies in this scheme are supercritical heat accumulator and regenerative compound turbocharging technology.First of all,this paper introduces the design of supercritical heat accumulator.The specific design content includes the design of the heat storage scheme,the design of the heat storage part,the design and check of the temperature control box,and the design of the measurement and control system of the supercritical accumulator.The design of heat storage part is to design the heat exchanger according to the thermal load and design target of the supercritical heat accumulator.The design of the thermostatic control box refers to the overall structure and the design of the total volume.The design of measurement and control system mainly includes hardware circuit design and software design.Secondly,the simulation analysis of supercritical heat accumulator is carried out.The simulation model of supercritical heat accumulator was built with GT-POWER software,and the feasibility of the model is verified.The research object of exhaust gas is determined,and the mean temperature AVG,standard deviation SD,validity Y,high efficiency H and comprehensive index ZH are selected as evaluation indexes.When R123,RC318 and R234 fa are used as working fluids respectively,the influence of the amount of working fluids on the temperature regulation performance of supercritical heat accumulator is analyzed.Finally,this paper introduces the simulation analysis of regenerative compound turbocharging system.Firstly,the model of regenerative compound turbocharging system is established with GT-POWER software.Then the performance of the engine with wastegate or not is simulated.Finally,the simulation verification of the function of improving intake response velocity of auxiliary charging system is carried out.The simulation results show that,2500r/min,10% load to 100% load,the time when the intake begins to increase is 1.5 seconds ahead of the original engine,the regenerative compound turbocharging system improves the intake responsiveness during transient loading. |
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