Refrigeration system with capacity control

摘要

A refrigeration system having at least one unloadable compressing apparatus and at least one always loaded compressing apparatus is provided with separate gas discharge lines connected to respectively separate condenser coil surfaces, and a valve arrangement is provided in those discharge lines connected to the unloadable compressing apparatus for closing those lines in response to an unloaded condition of the particular compressing apparatus serving the lines. The system has condenser coil surfaces matched to the unloading steps of the compressing apparatus. In one embodiment the valves in the discharge lines subject to being loaded or shut down are of the pilot type in which the pilot control is derived from the always loaded discharge line.