The Research On Electric Supercharging And Turbine Generator Of The Hybrid Supercharging System

The annual growth of car ownership has led to an increasing problem of energy security and environmental pollution.As an important part of the automobile,the engine is an essential tool to turn fuel chemical energy into mechanical energy.However,the engine's energy conversion rate is only 30 to 40 percent.How to save energy and recycle the residual energy becomes a hot research topic in the field of internal combustion engine.This paper mainly focuses on the defect of supercharged diesel engines,namely,low speed turbocharged diesel engine torque deficiencies,speed-up smoke,poor transient response and the low energy conversion efficiency.The parallel structure of electric supercharging system is adopted and the original supercharger to replace the original supercharger for rapid intake,as well as the series structure of the turbine generator system and the original supercharger to convert excess waste gas energy into electrical energy,which thereby increases the total output work of the engine.The study is of great practical significance.to energy conversation and environmental protection.The main research work is as follows:Theoretical analysis and modeling simulation are adopted to verify the feasibility of the technology of waste heat utilization.This paper contrasts turbocharged engine and complex turbo engine's ideal work cycle diagram and the diagram of constant pressure T-S and verifies that the loss of ventilation can be reduced and the energy utilization can be improved after the compound turbine is added.A model of the system of waste heat generation is set up based on the GT-power software to calculate and analyze the waste kinetic energy,waste heat energy,waste pressure energy and the total exhaust energy,which verifies the feasibility of the technology of waste heat utilization.The structure design of hybrid supercharging system.The parallel structure of electric supercharging system is adopted and the original supercharger as well as the series structure of the turbine generator system and the original supercharger.A new type of flat structure is designed to solve the problem of the overlong rotor shaft of the electric supercharger,insufficient coaxial degree of compressor and motor and the loose easily coupling nut.At the same time,The optical axis of the turbine shaft ends is combined with the drive nut inner hole to solve the insufficient coaxial degree and beating degree of turbine shaft and coupling.The hardware circuit design of hybrid supercharging system.Altium Designer is taken as the hardware development platform.And the modular design thinking is adopted to separate the cathode of the analog signal and the cathode of the digital signal from the cathode of the power supply to avoid the interference between signals,which enhances the system stability.This paper completes hardware circuit design including the STM32 chip minimum system,sensor input and output module and display interface,ect.and finally completes the design and manufacture of PCB..The software design of hybrid supercharging system.The software of Keil-uVision5 is taken as the software development platform and puts forward a new intelligent control strategy.This paper based on the electric supercharging system-inlet pressure MAP graph,sets the engine inlet pressure as the basic goal,uses fuzzy PID controller to real-time control the revolving speed of electric supercharger in order to ensure the expected intake pressure value.The engine exhaust port adopts by-pass valve to real-time control the working state of turbine generator.Based on the turbocharged diesel engine bench test method,the electr:ic boosting experiment,turbine generator experiment and the two systems work together testing scheme are designed to analyze the effect of mixed charging system on the overall performance of the engine.The results show that the hybrid supercharging system can effectively improve the power performance,emissions and fuel economy in low speed condition,and can recycle the energy of surplus waste gas,improve the total output power.The combined work of two subsystems of the hybrid supercharging system can further improve the power generation and total engine power.