双涡轮增压系统压气机通流特性匹配方法

Matching Method of Compressor Flow Characteristics for Dual Turbocharger System

通过离心式压气机特性图谱分析,建立了压气机通流特性模型来表征节流线。基于压气机通流特性模型,针对车用柴油机典型工况建立了性能指标函数,从而指导增压系统匹配方案的确定。针对典型双涡轮增压系统,明确了增压系统匹配流程,建立基于压气机通流特性的匹配方法。针对某型6缸增压柴油机不同工况的性能参数指标,进行了相继增压系统和可调两级增压系统匹配计算,分别进行了大小增压器和高低压级增压器选型。通过搭建柴油机相继和可调两级增压系统试验台架,试验验证了双涡轮增压系统匹配方案,试验结果表明,所匹配的相继和可调两级增压系统能够满足不同典型工况的压比和流量要求,进而实现柴油机不同工况的性能指标,保证了柴油机全工况范围的正常运行。同时根据柴油机试验结果,以燃油经济性最优为目标,确定了相继和可调两级增压系统全工况控制策略。

A compressor flow character ist ic model was built to characterize the throt tl ing line through the analysis of centri fu-gal compressor map. Based on the model, the performance index function was proposed to help the determination of matching scheme for typical working conditions of automobile diesel engine. The matching process and corresponding matching method were established for dual turbocharger system. Then the calculation of sequential turbocharging and two-stage turbocharging system and their turbocharger selection were conducted according to the performance indexes of a 6-cylinder diesel engine at dif-ferent working conditions. Finally, the scheme of dual turbocharge system was verified by the built test bench. The experimen-tal results show that the matched sequential and two-stage turbocharging systems can meet the requirements of pressure ratio and mass flow rate at different typical working conditions. The expecting performance index can also be achieved at different conditions, therefor the turbocharging system can apply to the whole conditions. In the end, the optimum fuel economy control strategies of whole working conditions are determined with the test results.