Abstract: A transport refrigeration system of the type which holds a set point temperature by way of heating and cooling cycles. A compressor discharge temperature control circuit is provided which senses the temperature of the hot compressor discharge gas and controls a flow of liquid refrigerant directly into the compressor suction line responsive to the sensed temperature. The receiver of the system is provided with hot gaseous refrigerant to thereby force liquid refrigerant therefrom which supplies the discharge temperature control circuit in all modes of operation.

Abstract: A transport refrigeration system of the type which holds a set point temperature via heating and cooling cycles. The system includes a refrigerant circuit which includes a compressor, condenser, receiver, evaporator, and a mode selection means for selectively directing hot compressed refrigerant gas to the condenser, or, through a hot gas conduit to the evaporator. The system includes a prime mover, typically a diesel engine for driving the compressor. The system includes a first hot gas flow control means having a predetermined, limited, refrigerant flow capability for controlling the flow of refrigerant therethrough. It further includes a second hot gas flow means having a refrigerant flow capability which is substantially greater than the predetermined limited refrigerant flow capability of the first hot gas flow control means. The first and second hot gas flow control means are disposed in parallel fluid flow relationship in the hot gas conduit.

Abstract: A transport refrigeration system of the type which holds a set point by operating in heating and cooling cycles. The system includes a compressor, a condenser and an evaporator each having inlet and outlet ports. A three-way valve receives compressed gas discharged from the compressor and directs it selectively to first and second outlets. First outlet of the three-way valve directs hot compressor gas to the condenser for operation of the system in a conventional cooling cycle. A hot gas conduit is provided which connects the second outlet of the three-way valve directly to the inlet of the evaporator. A branch line extends from the hot gas line to the line interconnecting the condenser and the evaporator, upstream of the receiver. Another refrigerant line extends from the outlet of the condenser to establish fluid communication with the line interconnecting the outlet of the evaporator with the compressor suction port.

Abstract: An internally compounded two-stage compressor has an interstage cooler and an oil separator associated therewith. The oil, and any hot gas mixed with it, discharged from the oil separator is passed in heat exchanger relationship with the cooling refrigerant flowing into the interstage cooler.

Abstract: A variable capacity refrigeration system and a fluid flow control device particularly well suited for use therewith. The fluid flow control device includes a body, a Belleville spring, and a plug. The body defines a fluid flow passage, and the plug is secured therewithin. The Belleville spring is positioned within the fluid flow passage and includes an inside edge defining a radially extending spring port for conducting fluid through the spring. The Belleville spring has a normal position, where the inside edge of the spring engages the plug to close the spring port, and an overcenter position, where the inside edge of the spring is spaced from the plug to allow fluid flow through the spring port.

Abstract: An engine-driven refrigeration unit includes a first heat exchanger functioning alternatively as a refrigerant condenser or as a refrigerant evaporator. When the heat exchanger is functioning as a refrigerant evaporator the heat transfer medium furnished thereto for providing a source of heat to vaporize the refrigerant is preheated by absorbing heat from a relatively warm fluid employed as the cooling medium for the engine driving the refrigeration unit.

Abstract: A refrigeration machine and a method of charging the same. The machine comprises a compressor, a condenser, an expansion device, and an evaporator connected together to form a closed loop, vapor compression refrigeration circuit. The condenser includes first and second parallel refrigerant condenser coils, and refrigerant is condensed with greater efficiency in the first condenser coil than in the second condenser coil. The refrigeration machine further comprises a first sight glass for disclosing the presence of refrigerant vapor in the refrigerant fluid discharged from the first condenser coil, and a second sight glass for disclosing the presence of refrigerant vapor in the refrigerant fluid discharged from the second condenser coil.

Abstract: An engine-driven refrigeration unit includes a first heat exchanger functioning alternatively as a refrigerant condenser or as a refrigerant evaporator. When the heat exchanger is functioning as a refrigerant evaporator the heat transfer medium furnished thereto for providing a source of heat to vaporize the refrigerant is preheated by absorbing heat from a relatively warm fluid employed as the cooling medium for the engine driving the refrigeration unit.

Abstract: A refrigeration system including a first evaporator having a capillary type expansion device controlling the flow of refrigerant thereto and a second evaporator having a thermal expansion valve for controlling the flow of refrigerant thereto. The system further includes a refrigerant compressor for discharging high pressure refrigerant vapor and a refrigerant condenser for receiving the high pressure refrigerant vapor and for converting the vaporous refrigerant to a relatively high pressure mixture of liquid and vaporous refrigerant. The system further includes a separator for receiving the relatively high pressure mixture from the condenser and for separating a substantial portion of the liquid refrigerant from the vapor liquid mixture. A first conduit is connected to the separator for delivering the separated liquid refrigerant to the thermal expansion valve and a second conduit is provided for delivering the remainder of the vapor liquid mixture to the capillary type expansion device.