Refrigeration system with de-superheating bypass

A method of operating a zoned refrigeration system with increased efficiency, the system being comprised of a primary refrigerant path including a compressor, a condenser, a primary expansion device, and a plurality of parallel-connected evaporator units located respectively to serve the zones of the space being refrigerated, the components being connected together to form a closed loop system with a refrigerant circulating therein, the method comprising the steps of:

• separately controlling the flow of refrigerant from the expansion device to each of the evaporator units so that refrigerant only flows through evaporator units which are required to provide cooling at a given time;
• diverting a portion of the refrigerant exiting the condenser into a bypass refrigerant line;
• passing the diverted refrigerant through a secondary expansion device in the bypass line;
• passing the refrigerant exiting the secondary expansion device through a heat exchanger thermally coupled to the primary refrigerant path between the compressor outlet and the condenser inlet to remove heat from the discharge vapor from the compressor, whereby the refrigerant exiting the compressor is at or near its saturation temperature;
• passing the refrigerant in the bypass path exiting the heat exchanger and the refrigerant exiting the evaporator through a pressure differential accommodating device that mixes two vapors at different pressures;
• and
• feeding the refrigerant exiting the pressure differential accommodating device to an inlet of the compressor,
• the quantity of refrigerant diverted to the bypass line being a predetermined minimum amount necessary to reduce the temperature of the refrigerant exiting the compressor to or near to its saturation temperature, plus an additional amount sufficient to reduce the cooling capacity to a decreased level if required at a given time, whereby variable cooling capacity can be achieved without the need to repeatedly adjust the operation of the compressor.

A refrigeration system comprising:

• a compressor, a condenser, an expansion device, and an evaporator, connected together to form a closed loop system with a refrigerant circulating therein;
• and
• a bypass path coupled between an outlet of the condenser and an inlet of the compressor, the bypass path including:
• a heat exchanger thermally coupled between an outlet of the compressor and an inlet of the condenser;
• and
• a pressure differential accommodating device having a first inlet connected to the outlet of the heat exchanger, a second inlet connected to the outlet of the evaporator, and an outlet connected to the inlet of the compressor,
• the heat exchanger being operative to reduce the temperature of refrigerant exiting the compressor from a superheated temperature to a temperature which is approximately equal to the saturation temperature, thereby reducing the condenser pressure, and consequently, the pressure lift at the compressor, and the compressor work.

A refrigeration system comprising:

• a compressor, a condenser, an expansion device, and an evaporator, connected together to form a closed loop system with a refrigerant circulating therein;
• and
• a bypass path coupled between an outlet of the condenser and an inlet of the compressor,
• the bypass path being comprised of:
• a heat exchanger thermally coupled between an outlet of the compressor and an inlet of the condenser;
• and
• a pressure differential accommodating device having a first inlet connected to the outlet of the heat exchanger, a second inlet connected to the outlet of the evaporator, and an outlet connected to the inlet of the compressor,
• the heat exchanger being operative to reduce the temperature of refrigerant exiting the compressor from a superheated temperature to a temperature which is approximately equal to the saturation temperature, thereby increasing the subcooling at the condenser outlet and consequently, the amount of liquid refrigerant passing into the evaporator, and the cooling capacity thereof.

A refrigeration system comprised of:

• a primary refrigerant path including a compressor, a condenser, a primary expansion device, and an evaporator connected together to form a closed loop system with a refrigerant circulating therein;
• and
• a bypass line connected between the outlet of the condenser and the inlet of the compressor, the bypass line including:
• a heat exchanger thermally coupled to the primary refrigerant path between the compressor outlet and the condenser inlet to remove heat from the discharge vapor from the compressor;
• and
• a pressure differential accommodating device for mixing two vapors at two different pressures connecting the outlets of the evaporator and the heat exchanger to an inlet of the compressor.