Termperature Control Logic For Refrigeration System

A refrigeration system comprising:

• a compressor having a first stage and a second stage;
• a motor driving the compressor;
• a heat rejecting heat exchanger having a fan drawing ambient fluid over the heat rejecting heat exchanger, the heat rejecting heat exchanger including an intercooler and a gas cooler, the intercooler coupled to an outlet of the first stage and the gas cooler coupled to an outlet of the second stage;
• a flash tank coupled to an outlet of the gas cooler;
• a primary expansion device coupled to an outlet of the flash tank;
• a heat absorbing heat exchanger coupled to an outlet of the primary expansion device, an outlet of the heat absorbing heat exchanger coupled to the suction port of the first stage;
• a controller for implementing a pulldown mode for cooling a space to a control temperature within a band of a control temperature setpoint, a control mode for maintaining the control temperature within the band of the control temperature setpoint and a staging logic mode for reducing system capacity while maintaining the control temperature within the band range of the control temperature setpoint.