Design And Research Of 8V150 Diesel Engine Turbocharging Exhaust System

In order to satisfy the requirement of power, environment and energy in the last few years, the design of the diesel engine becomes more and more elaborate. For four stroke turbocharging diesel engine especially for the high boost pressure diesel engine, to ensure the effectively use of the exhaust gas energy and the scavenging process between the cylinders successfully, more and more attention are paid on the design of exhaust system. There are two basic ways to the research of diesel engine exhaust gas system: one is through experiment, using the experimental data to improve the design of the exhaust gas system; the other is using the simulation tool to investigate the flow and energy usage in the exhaust system. Comparing with the experiment method, using the numerical simulation method can reduce the cost of the research, manpower and material resources greatly, shorten the developing cycle, moreover it can provide the results which cannot or difficult to be measured, and ample flow information at the same time. Based on the 8V150 turbocharging diesel engine, in order to improve the performance of the engine in full range, using GT-POWER to build the engine model, the exhaust system used was Pulse Converter system, calibrated the model both at 100% load and max. torque conditions according to the testing data; Then modified the exhaust system based on the previous model, MIXPC turbocharging system and optimized exhaust system were built up, multiple scheme analysis was carried through respectively. The results show that these two kinds of exhaust system both have preferable full range performance.In order to investigate the flow condition in the exhaust system, this paper build up three dimensional model, including Pulse Converter System and MIXPC system, using STAR-CD’s pre-processing tool for mesh generation; Coupled with GT-POWER, through analyzing the flow field, pressure field and energy dissipation rate distribution, the results show that MIXPC turbocharging system not only can slove the scavenging interfernce between cyliders at low condition but also have higher pulse energy utilization ratio than Pulse Converter System, besides with the compact structure and fast transient response it is suitible for eight cylinders tubocharging diesel engine.