Wide range refrigeration system with suction gas cooling

Claim 1

A refrigerant-compression temperature regulation system including compressor means for compressing said refrigerant in vapor and gaseous phase; condenser means downstream the compressor means for condensing the compressed refrigerant to liquid phase; first valve means downstream the condenser for creating a predetermined pressure drop; first evaporator means downstream the first valve means for transferring heat from a load to the refrigerant; suction gas return line means leading from the evaporator means to the compressor means for returning heated suction gas and vapor phase refrigerant to a suction inlet of the compressor means; and, first indirect heat exchanger means having a suction gas cooling path from the first valve means to upstream of the first evaporator means, the first indirect heat exchanger means for passively transferring heat from the gas and vapor phase refrigerant in the suction gas return line means to the vapor phase refrigerant entering the evaporator means and further comprising solenoid valve means between the condenser means and the first valve means, the solenoid valve means being opened in response to temperature of the load above a setpoint, and further comprising second valve means downstream of the condenser means and second indirect heat exchanger means having a suction gas cooling path from the second valve means to upstream of the first evaporator means, the second indirect heat exchanger means for passively transferring heat from the gas and vapor phase refrigerant in the suction gas return line means to the vapor phase refrigerant entering the evaporator means when the setpoint is above the load temperature and the solenoid valve means is closed.