Carrier Corporation

Jason D Scarcella

Alexander Lifson

KeonWoo Lee

Tobias H Sienel

Yu Chen

Suresh Duraisamy

Biswajit Mitra

Bruce J Poplawski

Douglas Auyer

Kursten Lamendola

Michael F Taras

Lei Chen

Jack Leon Esformes

Lucy Yi Liu

Hans-Joachim Huff

Thomas J Garosshen

Jianhua Zhou

Mark J Perkovich

Paul Valentine Weyna

Zvonko Asprovski

Mary Teresa Lombardo

William J Heffron

Hai Tian

Ping Sue Vang

Thomas J Benedict

Dennis M Stone

Thomas A Anderson

Martin O Johnsen

Douglas R Auyer

Keonwoo Lee

Yu H Chen

Miswajit Mitra

Daqing Li

Kurt Handley

A refrigerant vapor compression system comprising a plurality of components connected in a refrigerant flow circuit by a plurality of refrigerant lines, said components including: a compression device; a refrigerant heat rejection heat exchanger; a first expansion device; a refrigerant heat absorption heat exchanger; and a flash tank system having a first flash tank operably coupled to a second flash tank by a first connection, the flash tank system being disposed in the refrigerant flow circuit between the refrigerant heat rejection heat exchanger and the refrigerant heat absorption heat exchanger.

Refrigerant vapor compression system with multiple flash tanks

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 rejection heat exchanger is disposed downstream with respect to refrigerant flow of the second compression stage. A first refrigerant intercooler is disposed intermediate the first compression stage and the second compression stage. The first refrigerant intercooler is disposed downstream of the first refrigerant heat rejection heat exchanger with respect to the flow of the first secondary fluid. An economizer includes a vapor line in fluid communication with a suction inlet to the second compression stage. A second refrigerant heat rejection heat exchanger is disposed intermediate with respect to refrigerant flow of the second compression stage and the first refrigerant heat rejection heat exchanger. A second refrigerant intercooler is disposed intermediate the first compression stage and the second compression.

Refrigerant vapor compression system

A compact heat exchanger assembly for a refrigeration system includes a heat rejection heat exchanger assembly and a heat absorption heat exchanger assembly. The heat rejection heat exchanger assembly includes a primary heat exchanger and a secondary heat exchanger. The primary heat exchanger has a tube bank extending between a first manifold and a second manifold. The tube bank being provided with at least one bend such that the primary heat exchanger has a generally curvilinear shape. The secondary heat exchanger is disposed between the first manifold and the second manifold.

Compact heat exchanger assembly for a refrigeration system

A method of mitigating refrigerant leaks within a refrigeration system that includes: detecting a leak of a refrigerant from a refrigeration system; closing a first valve to inhibit a fluid flow of the refrigerant between an evaporator and a condenser fluidly connected to the evaporator; and operating a compressor to direct another fluid flow of the refrigerant from the evaporator to the compressor.

Refrigerant leak detection system

A refrigeration system includes a refrigerant vapor compression unit including a compressor and one or more current sensors to determine a total system current draw. One or more pressure sensors are positioned to determine a refrigerant pressure in the refrigerant vapor compression unit. A controller compares the current draw on the system and the refrigerant pressure to selected acceptable ranges and determines a level of refrigerant charge in the refrigerant vapor compression unit. A method of determining a level of refrigerant charge in a refrigeration system includes measuring a refrigerant pressure in the refrigeration system and sensing a current draw of the refrigeration system. A level of refrigerant charge in the refrigeration system is calculated from the refrigerant pressure and the current draw.

Refrigerant level monitor for refrigeration system

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.

Carbon dioxide refrigerant vapor compression system

A flash tank economizer includes a sensor for sensing a condition indicative of pressure in the flash tank, and when that pressure is found to equal or exceed the critical pressure of the particular refrigerant being used, a controller responsively closes a valve in the economizer vapor line to shut off the economizer. A sensor is also provided to sense the pressure at the compressor mid-stage, and if that pressure is found to exceed the pressure in the flash tank, the controller causes the flow control device to function so as to prevent the flow of refrigerant from the compressor mid-stage to the flash tank. Provision is also made for selectively draining refrigerant from the flash tank to reduce the pressure therein from a supercritical to a subcritical condition.

Flash tank economizer cycle control

A refrigerated cargo container includes a cargo container and a refrigeration unit. A plurality of refrigerant tubes are in fluid communication with the refrigeration unit and extend along a roof of the cargo container. The plurality of refrigeration tubes are configured to convey refrigerant there through and cool an interior of the cargo container via natural convection and thermal radiation. A method of cooling a cargo in a cargo container includes flowing a refrigerant through a plurality of refrigerant tubes disposed at a roof of the cargo container. Thermal energy is transferred from container air in the container to the refrigerant thereby cooling the container air. The container air is circulated via natural convection toward the cargo thereby cooling the cargo via thermal energy transfer to the container air. The container air is recirculated toward the plurality of refrigerant tubes.

Refrigerated cargo container, method for cooling a cargo, method for heating a cargo

A suction modulation valve is throttled when conditions in a refrigerant system indicate that an undesirable amount of liquid refrigerant might otherwise be delivered to the compressor. As an example, the throttling would occur at start-up, among other conditions. Throttling the suction modulation valve reduces the amount of refrigerant reaching the compressor and thus ensures that any liquid refrigerant would be likely 'boiled off' before raising any problems in the compressor. Other control steps can also be performed to alleviate flooded compressor operation with liquid refrigerant. Such steps, for example, can include actuating heaters, discharge valve throttling, by-passing refrigerant from an intermediate compression point back to suction, controlling the speed of the condenser fan can be performed independently or in combination including the suction modulation valve throttling.

Refrigerant system with control to address flooded compressor operation

A refrigerant vapor compression system includes a flash tank economizer defining a separation chamber is disposed in the refrigerant circuit intermediate a refrigerant heat rejection heat exchanger and a refrigerant heat absorption heat exchanger. A primary expansion valve is interdisposed in the refrigerant circuit in operative association with and upstream of the refrigerant heat absorption heat exchanger and a secondary expansion valve is interdisposed in the refrigerant circuit in operative association and upstream of the flash tank economizer. A refrigerant vapor injection line establishes refrigerant flow communication between an upper portion of the separation chamber and an intermediate pressure stage of the system's compression device and a suction pressure portion of the refrigerant circuit. A refrigerant liquid injection line establishes refrigerant flow communication between a lower portion of said separation chamber and an intermediate pressure stage of the compression device and a suction pressure portion of the refrigerant circuit.

Refrigerant vapor compression system and method of transcritical operation

A refrigerant vapor compression system is provided that includes a refrigerant circuit and a lubricant cooler circuit. The lubricant cooler circuit is operatively associated with the compression device for cooling a lubricant associated with the compression device and includes a heat exchanger coil disposed downstream of the refrigerant heat absorption heat exchanger with respect to the flow of heating medium. The lubricant cooler heat exchanger defines a flow path for passing the lubricant in heat exchange relationship with the cooled heating medium leaving the refrigerant heat absorption heat exchanger.

Refrigerant vapor compression system with lubricant cooler

In a method of operating a compressor at startup, the compressor is rotated in reverse for a brief period of time. The compressor is of a type that does not compress liquid when rotated in reverse. The purpose is to boil off the liquid refrigerant from the oil by heating and agitating the mixture of oil and refrigerant in the oil sump. This results in a much more benign forward start as less refrigerant is drawn into the compressor pump and the amount of oil pumped out of the compressor on start up is minimized. Also, the viscosity of oil is increased and lubrication of the bearings is improved. After a short period of time reverse rotation is stopped and the compressor can start rotating in the forward direction. The short period of time of reverse rotation is varied based upon system conditions. In one embodiment, the variation can occur by reducing the reverse run time as ambient temperature increases. In another embodiment, electrical conditions such as incoming voltage and/or a ratio of voltage to frequency can be utilized to change the reverse run time.

Compressor reverse rotation of variable duration on start-up

A refrigeration circuit having a system charge and a system charge storage area. The system charge area has a condenser having a set of micro-channel heat exchanger coils. The condenser is appropriately sized to receive a first volume of the system charge. There is a compressor for compressing the system charge from an expanded state to a compressed state. There is a sealed refrigerant charge holding area fluidly connected to the condenser and the compressor. The sealed refrigerant charge holding area is appropriately sized for storing a second volume of the system charge during a system pumpdown. A receiver is fluidly connected to the sealed refrigerant charge holding area. The receiver is appropriately sized to receive a third volume of the system charge during a system pumpdown.

Refrigeration circuit

A refrigeration unit for a shipping container exposed to end loads and rack loads. The refrigeration unit has a frame, a back panel, a plurality of structural support brackets secured to the back panel, a condenser cover secured to the plurality of structural support brackets so that the condenser cover, the plurality of structural support brackets, the frame, and the back panel form a structural member sufficient to support end loads and rack loads. The refrigeration unit also has a condenser coil having a first end and a second end, a first coil support member secured to one of the structural support brackets and secured around the first end, and a second coil support member secured to one of the structural support brackets and secured around the second end. The first and second coil support members maintain the condenser coil unstressed from the end loads and rack loads.

Refrigeration unit with integrated structural condenser coil support

A refrigerant system includes a compressor that has safe operating limits that are also built into a refrigerant system control to protect the compressor. Under certain conditions, these safe operational limits may be changed to allow the compressor to operate beyond the safety limits at least for a period of time.

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Cicero, NY, United States of America

Jason D Scarcella