Methods for the use of moveable inlet guide vanes in the turbo expander and compressor inlet

摘要

A turboexpander-compressor system includes an expander configured to expand an incoming gas, a first set of moveable inlet guide vanes configured to control a pressure of the incoming gas, a compressor configured to compress a gas received from the expander, a shaft configured to support and rotate an expander impeller and a compressor impeller, a second set of moveable inlet guide vanes attached to the compressor and configured to control a pressure of the gas input into the compressor, and a controller configured to acquire information about a rotating speed of the shaft, a pressure and a temperature of the incoming gas, a pressure and a temperature of the gas output from the expander, and to control the second set of moveable inlet guide vanes to maximize a ratio between the rotating speed of the shaft and a drop of an enthalpy across the expander, in off-design conditions.