Abstract: A method is provided for protecting a refrigerant vapor compression system during a standstill period following shutdown of the refrigerant vapor compression system. A method is provided for detecting a low refrigerant charge level in a refrigerant vapor compression system operating in a transcritical mode. A refrigerant vapor compression system is provided that includes a controller operative to perform a refrigerant charge detection method.

Abstract: A refrigerant vapor compression system includes a compression device having at least a first compression stage and a second compression stage arranged in series refrigerant flow relationship; a first refrigerant heat rejecting heat exchanger disposed downstream with respect to refrigerant flow of the second compression stage for passing the refrigerant in heat exchange relationship with a first secondary fluid; a second refrigerant heat rejecting heat exchanger disposed downstream with respect to refrigerant flow of the first refrigerant heat rejecting heat exchanger for passing the refrigerant in heat exchange relationship with a second secondary fluid.

Abstract: A refrigerant vapor compression system includes a compression device having at least a first compression stage and a second compression stage, a refrigerant heat rejection heat exchanger disposed downstream with respect to refrigerant flow of the second compression stage, and a refrigerant intercooler disposed intermediate the first compression stage and the second compression stage. The refrigerant intercooler is disposed downstream of the refrigerant heat rejection heat exchanger with respect to the flow of a secondary fluid. A second refrigerant heat rejection heat exchanger may be disposed downstream with respect to refrigerant flow of the aforesaid refrigerant heat rejection heat exchanger, and a second refrigerant intercooler may be disposed intermediate the first compression stage and the second compression stage and downstream with respect to refrigerant flow of the aforesaid refrigerant intercooler.

Abstract: A CO2 vapor compression system is provided with at least one pressure relief device which is designed to open when the pressure in the low pressure side exceeds the predetermined level because of exposure to high temperatures during non-operational periods. A pressure relief device is provided near the compressor suction inlet to relieve one section of the circuit and another is provided upstream of an unloading valve to relieve pressure in another section thereof.

Abstract: A carbon dioxide refrigerant vapor compression system and method of operating that system are provided. The refrigerant vapor compression system includes a compression device, a flash tank receiver disposed in the refrigerant circuit intermediate a refrigerant heat rejection heat exchanger and a refrigerant heat absorption heat exchanger, and a compressor unload circuit including a refrigerant line establishing refrigerant flow communication between an intermediate pressure stage of the compression device and the refrigerant circuit at a location downstream of the refrigerant heat absorption heat exchanger and upstream of a suction inlet to the compression device, and a unload circuit flow control device disposed in said unload circuit refrigerant line. In response to at least one system operating parameter sensed by at least one sensor, the controller selectively positions the unload flow control device to maintain the refrigerant vapor compression system operating below a preselected high pressure limit.

Abstract: A phase separation apparatus is provided for separating a two-phase fluid flow into a liquid phase portion and a vapor phase portion. The phase separation apparatus may be applied to the separation of a two-phase refrigerant flow in a refrigerant vapor compression system operating in a transcritical cycle.

Abstract: A phase separation apparatus is provided for separating a two-phase fluid flow into a liquid phase portion and a vapor phase portion. The phase separation apparatus may be applied to the separation of a two-phase refrigerant flow in a refrigerant vapor compression system operating in a transcritical cycle.

Abstract: A pressure relief valve (20) for use in connection with a high pressure fluid system has a protective cap (22) for limiting the exposure of personnel to high pressure fluid venting from the pressure relief valve. In an embodiment, the protective cap includes a cylindrical cap body (52) mounted to a distal end (28) of the valve body (24) of the pressure relief valve and a skirt flange (54) extending circumferentially about an open end of the cap body for deflecting the streams of high pressure fluid venting from the pressure relief valve away from an outwardly directed path. A circumferential seal body (70) may be disposed between an inner circumferential surface (66) of the cap body and an outer circumferential surface (68) of the distal end of the valve body.

Abstract: A refrigerated container having a refrigeration system using CO2 as the refrigerant, includes a sensing and warning system for sensing the CO2 concentration in the container and responsively displaying the sensed condition in a display module so that an operator will be aware of excess levels of concentration which might present a hazardous condition and therefore should not enter the container until the condition is alleviated.

Abstract: A phase separation apparatus is provided for separating a two-phase fluid flow into a liquid phase portion and a vapor phase portion. The phase separation apparatus may be applied to the separation of a two-phase refrigerant flow in a refrigerant vapor compression system operating in a transcritical cycle.

Abstract: A refrigerant vapor compression system includes a compression device having at least a first compression stage and a second compression stage, a refrigerant heat rejection heat exchanger disposed downstream with respect to refrigerant flow of the second compression stage, and a refrigerant intercooler disposed intermediate the first compression stage and the second compression stage. The refrigerant intercooler is disposed downstream of the refrigerant heat rejection heat exchanger with respect to the flow of a secondary fluid. A second refrigerant heat rejection heat exchanger may be disposed downstream with respect to refrigerant flow of the aforesaid refrigerant heat rejection heat exchanger, and a second refrigerant intercooler may be disposed intermediate the first compression stage and the second compression stage and downstream with respect to refrigerant flow of the aforesaid refrigerant intercooler.

Abstract: A method is provided for protecting a refrigerant vapor compression system during a standstill period following shutdown of the refrigerant vapor compression system. A method is provided for detecting a low refrigerant charge level in a refrigerant vapor compression system operating in a transcritical mode. A refrigerant vapor compression system is provided that includes a controller operative to perform a refrigerant charge detection method.

Abstract: A refrigerant vapor compression system includes a compressor having a suction port and a discharge port, an air-cooled heat exchanger operatively coupled to the discharge port, a liquid-cooled heat exchanger operatively coupled to the air-cooled heat exchanger, a coolant pump operatively coupled to a liquid coolant inlet conduit of the liquid-cooled heat exchanger, an evaporator heat exchanger unit operatively coupled to the liquid-cooled heat exchanger and the suction port, a coolant pump operatively coupled to the liquid coolant inlet conduit for pumping a liquid coolant, and a controller operatively associated with the liquid coolant inlet conduit for controlling the flow of liquid coolant into the liquid-cooled heat exchanger. In one embodiment, the liquid-cooled heat exchanger comprises a low-profile enclosure defining an interior volume.

Abstract: An activation indicator for a refrigeration system pressure relief valve is presented. In one embodiment, the indicator comprises a covering that covers an outlet passage of the pressure relief valve. The covering is at least partially displaceable by refrigerant as it exits the refrigeration system through the pressure relief valve. In another embodiment, sensors outputting a signal transmit an altered signal when the relief device releases refrigerant. A notification device is activated to indicate that the pressure relief device has activated.

Abstract: A carbon dioxide refrigerant vapor compression system and method of operating that system are provided. The refrigerant vapor compression system includes a compression device, a flash tank receiver disposed in the refrigerant circuit intermediate a refrigerant heat rejection heat exchanger and a refrigerant heat absorption heat exchanger, and a compressor unload circuit including a refrigerant line establishing refrigerant flow communication between an intermediate pressure stage of the compression device and the refrigerant circuit at a location downstream of the refrigerant heat absorption heat exchanger and upstream of a suction inlet to the compression device, and a unload circuit flow control device disposed in said unload circuit refrigerant line. In response to at least one system operating parameter sensed by at least one sensor, the controller selectively positions the unload flow control device to maintain the refrigerant vapor compression system operating below a preselected high pressure limit.

Abstract: A CO2 vapor compression system is provided with at least one pressure relief device which is designed to open when the pressure in the low pressure side exceeds the predetermined level because of exposure to high temperatures during non-operational periods. A pressure relief device is provided near the compressor suction inlet to relieve one section of the circuit and another is provided upstream of an unloading valve to relieve pressure in another section thereof.

Abstract: A plurality of pressure relief devices are disposed within a refrigeration circuit, and each of the pressure relief devices is located within a compartment that fluidly communicates with the ambient air. Each of the pressure relief devices is oriented so that the release of high pressure vapor therefrom is directed to a rear wall of the compartment. Further, a four sided cover is disposed over each of the pressure relief devices so as to partially contain any released vapor and allow it to be discharged in one direction only.

Abstract: A refrigerated container having a refrigeration system using CO2 as the refrigerant, includes a sensing and warning system for sensing the CO2 concentration in the container and responsively displaying the sensed condition in a display module so that an operator will be aware of excess levels of concentration which might present a hazardous condition and therefore should not enter the container until the condition is alleviated.