Abstract:

For the high pressure ratio centrifugal compressor of turbocharger, based on plateau environment simulation test rig for inlet environment system, do study on experimental investigation for impact on compressor performance at high altitude in order to deal with the problem of compressor characteristic estimation with diesel engine at plateau regions. The research data analysis show the following conclusions: At the high altitude, the mass flow rate of compressor decrease, the maximum pressure ratio at the same speed hold approximately invariability, but the efficiency and Reynolds number reduce too. From 1 000 m altitude to 4 500 m altitude, the mass flow rate decrease by 26%-44%, and the efficiency have 1-3.5 percentage fall. The inlet Reynolds number decrease by 30% , cause to more than 50% operation out of the self-mode critical region. The stable flow range is going to broad, and the maximum increase is 11%. The volume flow rate of compressor decrease at high altitude from 1 000 m altitude to 4 500 m, the maximum flow rate decrease is 3%, smaller than the referred parameter difference. The general characteristics with referred parameter have the big difference at high altitude, especially for 4 500 m altitude, don’t have comparative and reference function. The general characteristics with similitude parameter have small change, can be used to research on different altitude contrast. At high altitude, due to the effect of Reynolds number, the general performance characteristics based on Mach number similitude theory don’t have good and exact results, and we have to use the actual flow rate and speed performance characteristics in study on high altitude, but the method with similitude parameter can clearly and directly compare on different altitude performance.

Key words: performance, plateau environment, Reynolds number, turbocharger, centrifugal compressor