Test Evaluation of Stationary and Rotating Diffusers for a High Pressure Ratio Radial Compressor.

摘要

The design of a free rotating vaneless/vaned diffuser (F.R.D.) for a nominal 1.9 pps, high pressure ratio, single stage radial compressor was completed, together with a comparative conventional stationary vaneless/vaned optimum channel diffuser. Both types of diffuser were subsequently fabricated and individually installed in an existing turbodrive compressor rig for comparative performance evaluation. At 100% corrected design impeller speed, equal to 62,000 rpm, the peak pressure ratio and adiabatic efficiency for the stationary and F.R.D. systems were 7.91 and 72.6% compared to 7.43 and 70%, respectively. Impeller efficiency was not repeatable and reduced 3.8% at design speed with the F.R.D. installed, probably as a result of different radial clearance settings. Overall peak vaneless/vaned diffuser static pressure recovery was essentially the same (0.61) at design speed with either the stationary or F.R.D. systems. (Author)