The Development Of Some Type Of Two-stage Turbocharged Diesel Of Yuchai And Application Of Touring Coach

With the development of diesel technology, the pressure ratio provided by single-stage supercharging can’t meet the requirement of high power diesel engine, two-phase supercharging diesel engine has a wide adjustment range of pressure ratio and a high excess air ratio, which increase performance per liter and torque output at low speed, and can effectively improve acceleration performance, fuel consumption at low speed and exhaust emissions. Based on a prototype of 8.4L diesel engine, we researched on the two-phase supercharging diesel engine, using AVL-BOOST software to simulate and analysis the two-phase supercharging model, which is verified by bench test. Finally, the bus model is simulated by AVL-CRUISE and the passenger vehicle taken a road test. Some work has been done on these problems as follows:(1) Expounded the classification of diesel engine turbocharger, working principle and advantages and disadvantages, we also analyzed the technology of diesel engine exhaust gas turbocharger, and the sequential two-stage supercharging and the adjustable two-stage supercharging technology which derived from diesel engine exhaust gas turbo technology, using AVL-BOOST software which takes the data from the prototype diesel engine to simulate and compare four types of turbochargers. Analyzing the results of simulation and experiment on five load operating points 900 rpm, 1330 rpm, 1600 rpm, 1990 rpm and 2200 rpm, the accuracy of the model is demarcated, and analyzing the advantages and disadvantages of the matching scheme of turbocharger and diesel engine.(2) According to a secondary turbocharged diesel engine the simulated model and the test-bed are set up, analyzed the engine performance by compared the experimental data with the prototype data, and the analysis was focused on the advantages of the torque and power output, the inlet flow and cold pressure before entering, the pressure and temperature before turbine and specific fuel consumption of the two-phase supercharging diesel engine.(3) Analyzed the merits of two-phase supercharging diesel engine when compared with single-stage supercharging diesel engine, the simulation and optimization of the passenger vehicle which was used the technology of two-phase supercharging were conducted, and taken vehicle road actual verification experiment. The researches found that the power performance of the passenger vehicle is increased about 10%, and improve the fuel economy 4.82%. Those indicate that the use of two-phase supercharging technology can really improve the performance of diesel engine, which has great practical significance to improve the vehicle driving performance and the energy saving and emissions reduction.