二级增压系统中高压级压气机性能研究

Performance of the high pressure stage compressor of a two-stage turbocharging system

为使高低两级压气机达到优化匹配,提高整个二级增压系统的效率,在二级增压系统试验台架上对高压级压气机的性能进行了研究。通过在增压系统中,使新鲜空气首先通过低压级压气机进行预压缩,提高其温度和压力,从而得到高压级压气机的高温高压进口条件。在两级压气机之间设置中冷器,使每一条等转速曲线,高压级压气机进口温度保持不变。试验结果表明,由于进口温度提高,压气机折合转速与实际转速相差较大,为达到预定压比,必须进一步提高压气机转速;进口压力大幅度提高是造成高压级压气机折合流量偏小的主要原因;为避免高压级压气机发生喘振,应控制高压级压气机的进口压力。

To make the high pressure（HP） stage compressor and the low pressure（LP） match with optimization and improve the efficiency of the whole two-stage turbo-charging system,the performance of a HP stage compressor was studied on a two-stage turbo-charging system test bench.In the turbo-charging system,the fresh air was first pre-compressed through the LP stage compressor to get the HP stage compressor′s inlet condition with high pressure high temperature.An intercooler was set between the HP and LP stage compressors.To each test curve had the same rotation speed,and the inlet temperature of the HP stage compressor was kept unchanged.The test results showed that there was much difference between the corrected speed and actual speed of the HP stage compressor only because the increase of its inlet temperature.In order to get the preconcerted pressure ratio,the speed of the HP stage compressor should be much improved.The corrected air mass flow of HP stage compressor was much less than its measured air mass flow,which was mainly because the great increase of inlet pressure of the HP stage compressor.In order to avoid a surge of the HP stage compressor,its inlet pressure should be controlled.