Performance of a Centrifugal Air Compressor Plant at Low Pressures

摘要

Centrifugal air compressors are normally operated at or near design conditions, but in the operation of a supersonic wind tunnel facility the compressors may be operated over a wide range of compression ratios and pressure levels. The compressor plant number 1 at the Supersonic Wind tunnels of the Ballistic Research Laboratories (BRL) may be operated through a range of 15 to 600 cm Hg abs dischage air pressures and compression ratios from 1.2 to 30 by proper staging of compressors. This report covers compressor plant performance with the plant in its three-stage arrangement and for discharge air pressures from 150 to 15 cm Hg abs, using of the supersonic wind tunnels as an orifice to obtain volume flows. As the pressure level to the first stage decreases below 25 cm Hg abs, the indication is that the size of the compressor plant decreases. Also shown is the Mach number variation with decreasing pressure. (Author)