Surge preventer in compressor driven system - detects variation in given system parameter and changes capacity of compressor accordingly

摘要

Surge in a compressor-driven system, such as a refrigeration system, is prevented by sensing an appropriate parameter, for example the gas flow at the compressor discharge outlet. A feedback signal, which dynamically varies the capacity of the compressor is developed so that the discharge pressure versus discharge flow rate characteristic curve of the compressor always has a negative slope at the operating point. By providing a negative slope at all operating conditions, the system is incapable of surge. In order to satisfy variable load requirements, the compressor capacity is adjusted to vary the steady state operating point on the characteristic curve.