Match And Study On Two-stage Sequential Turbocharging System For Diesel Engine

With the gradual development of supercharging technology, it gradually cannot meet therequirements that the diesel engine has high brake mean effective pressure and excellentperformance of the full range of operating conditions. At present, to solve the disadvantagesof the traditional supercharging technology has developed a variety of pressurization system,which is the most representative and will be widely application is the sequential turbochargingsystem, the sequential turbocharging system can effectively improve the low loadcharacteristics of the diesel engine, but the one-stage sequential turbocharging system can notprovide high pressure ratio. The design of the two-stage supercharging system for dieselengine can provide high pressure ratio, and can effectively improve the low conditionperformance.The one-stage sequential turbocharging system of the original machine is reformed fortwo-stage sequential turbocharging system to achieve the power increased by30%. Based onthe power strengthening goal, the fuel, air quantity and inlet pressure are estimated in thediesel engine matching point. According to the estimation results select the high and lowpressure stage turbocharger for the two-stage sequential turbocharging system, and the dieselengine and the two-stage sequential turbocharging system are integrated operation to verifythe supercharger is appropriate.According to the structural parameters of the diesel engine TBD234V12, this paper buildthe one-stage sequential turbocharging steady-state simulation model by the GT-Powersoftware, the simulation results compare with experimental data to check the accuracy of themodel. Based on the one-stage sequential turbocharging simulation model of diesel enginecan build the two-stage sequential turbocharging steady-state simulation model by usingGT-Power software, the diesel engine mechanical load and thermal load are reduced by thesimulation optimizing of the diesel engine’s compression ratio, fuel supply advance angle,valve overlap angle and air cooling mode, the optimization simulation results of the dieselengine are compared with the original machine to analyze the variation of the power,economy and other performance parameters of the diesel engine that use the two-stagesequential turbocharging system, and according to the efficiency of supercharger and diesel engine select the switch point of the two-stage sequential turbocharging system.Based on the steady-state simulation model can build the two sequential turbochargingtransient simulation model by using GT-Power software. According to the simulationcalculation can determine the best switching delay of the two-stage sequential turbochargingsystem. Meanwhile, in the same switching delay, only change the size of the moment ofinertia of the supercharger to analyze the moment of inertia to the influence of the transientswitching process, the results of simulation calculation can obtain the transient response speedof the turbocharger and the switching delay with the variation of the moment of inertia.