Matching Law And Control Strategy Of Diesel Engine Power Turbine Energy Recovery And Electric Turbocharging

Increasing engine thermal efficiency and reducing CO2 emissions are among the major challenges facing the international internal combustion engine industry.About 30% to 40% of the energy released by fuel combustion in the engine is lost to the atmosphere through the exhaust gas,and is not effectively utilized.To this end,this paper proposes a research program for power turbine power generation-electric auxiliary booster power,and studies the influence law of the intake and exhaust system on the exhaust pulse energy,and the matching characteristics of the power turbine and the electronic supercharger.A management strategy for exhaust pulse energy recovery and utilization is proposed to achieve optimal system total energy efficiency.Based on a heavy-duty diesel engine,this paper builds an engine test bench and builds an engine performance simulation platform based on GT-SIUTE one-dimensional thermodynamics software.Firstly,based on the simulation model,the influence law of the gas distribution parameters of the intake and exhaust valves on the engine performance is studied.The influence law of the exhaust structure parameters is revealed.The results show that the exhaust pipe diameter is very obvious for the utilization of exhaust energy.The smaller the diameter of the main pipe,the larger the pulse energy.However,if the diameter of the exhaust pipe is too small,the gas flow rate will be too fast,resulting in increased flow friction loss.The use of exhaust pulse energy is disadvantageous.Secondly,the simulation model of the series power generation turbine composite system is built.The control law of the power turbine flow area coefficient,the power turbine bypass valve and the power turbine speed on the total energy efficiency of the system is studied.The results show that the total energy efficiency of the system mainly depends on the break-even state between the recovery energy of the power turbine and the pumping loss.Thirdly,the electric auxiliary supercharging model is built.The influence of the electronic supercharger on the engine's power,economy and torque response under external characteristic conditions is studied.The results show that the electronic supercharger is involved in the engine in the low speed region.The power,economy and torque response all have good improvement effects,and as the speed increases,the improvement effect gradually declines to deteriorate.Finally,based on the optimization of intake and exhaust system and the matching characteristics of power turbine and electronic supercharger,the whole process management strategy of pulse energy recovery and utilization is proposed.The results show that under the WHC cycle test conditions,the total energy efficiency of the engine system is increased by 2.32% on average,which verifies the effectiveness of the proposed joint management strategy.