Research On Selecting And Matching Turbo System Of Vehicle Diesel Engine

Turbocharging technology can greatly enhance engine power and improve fuel economy and emission performance as well. Since the traditional turbocharging technology is already very mature, it is now widely used in vehicle diesel engines. In appling turbocharging technology, it is always very important to achieve a good match between turbocharger and engine.In recent years, in order to achieve higher power and fuel economy performance, to meet ever-increasing stringent emissions regulations, many kinds of state-of-the-art turbo system, including electric-controlled wastegate turbocharger, variable geometry turbocharger, sequence turbocharger and regulated two-stage turbocharger, have been developed and gradually applied to the diesel engines. It is a difficult task to select proper turbocharger to achieve a good match with engine, especially when introducing these new turbo systems into diesel engines.In this paper, according to the research on these turbo matching technologies, a vehicle diesel engine model for turbo matching is created and a software"TurboMatch"is developed based on Visual C++. The software can be easily used at selecting and matching turbocharger for diesel engines. On the basis of GT-POWER, one-dimensional turbocharged diesel engine is modeled with some different turbocharger solutions. After calculations and comparison with engine test datas and result obtained by GT-POWER, it turns out the accuracy and efficiency of"TurboMatch".In this paper, to make research on the matching between turbocharger and diesel engine with EGR system, simple thermodynamic models are created, separately for high pressure and low pressure EGR system. Also some calculation and analysis of the engine-turbocharger matching is made after introducing EGR system into turbocharged diesel engine. Based on GT-POWER,the two kinds of EGR system models are established and the EGR rate is regulated to calculate the diesel performance. Some quantitative analysis is made and the result proves the accuracy of the thermodynamic models of EGR system in"TurboMatch". Thus these researches can provide guideline of matching turbocharger for diesel engines with EGR system.