Abstract: A refrigeration circuit has a mono- or multi-component refrigerant, especially CO2, circulating therein, said refrigeration circuit enabling an transcritical operation, said refrigeration circuit comprising, in the direction of refrigerant flow, a compressor unit, a condenser/gascooler, a high pressure control valve, a collecting container, and at least one evaporator having an expansion device connected upstream thereof, wherein a flashgas line having a medium pressure control valve arranged therein is provided between an upper portion of the collecting container and the suction line leading to the compressor unit, wherein a temperature, pressure or liquid level sensor is provided in or at the collecting container, wherein a bypass line having a medium pressure holding valve arranged therein is provided connecting the line between the condenser/gascooler and the high pressure control valve to the line between the collecting container and the expansion device(s), and wherein a control unit is provided said co

Abstract: A compressor (2) for a refrigeration cycle according to the invention comprises an inlet port (6), a compression element (10), an outlet port (18), wherein in operation a refrigerant flow (20) of a gaseous refrigerant carrying an amount of oil circulates through the inlet port (6), the compression element (10) and the outlet port (18), and an oil sump (8) in which part of the oil carried by the gaseous refrigerant collects. An oil circulation rate enhancement feature (16) is provided being configured so as to direct oil from the oil sump (8) to the refrigerant flow (20), when the oil in the oil sump (8) exceeds a predetermined oil sump level (24).

Abstract: A heat pump, and in particular a heat pump for heating a hot water supply is provided with an improved defrost mode. The defrost mode is actuated to remove frost from an outdoor evaporator that may accumulate during cold weather operation. An algorithm for operation of the defrost mode is developed experimentally by seeking to maximize the heat transfer provided by the refrigerant. A heating system condition is experimentally related to the heat transfer capacity. One then maximizes the average heat transfer capacity to determine the optimum initiation point for the defrost mode. Further, protections are included into the defrost mode. When the heat pump is utilized to heat hot water, methods are provided to prevent the water that remains in the heat exchanger from becoming unduly heated. In one method, the water pump may be periodically operated to move the water.

Abstract: A refrigeration device containing CO2 a refrigerant to be circulated, comprising: a compressor (1, 10, 11), a heat-rejecting heat exchanger (3, 30), an expansion device (7a, 7b, 70a, 70b, 71), and an evaporator (8a, 8b, 80a, 80b, 81) which are connected to one another, wherein the refrigeration device comprises a first portion (61, 71, 81, 11, 92, 10) and a second portion (60, 70a, 80a, 90, 10), the second portion having a higher temperature relative to the first portion when the refrigeration device is in operation; and a heat-reclaim heat exchanger (E1, E2, E3, E4) provided at a given location in the second portion, provided to transfer heat to a fluid for further use as a source of heated fluid.

Abstract: A heat pump system includes a compressor, a heat rejecting heat exchanger, an expansion device, and a heat accepting heat exchanger. A storage tank stores the water that cools the refrigerant in the heat rejecting heat exchanger. A mechanical interface plate positioned between a hot water reservoir and a cold water reservoir in the storage tank reduces heat transfer between the hot water and the cold water. During a water heating mode, cold water from the cold reservoir flows into the heat sink to cool the refrigerant in the heat rejecting heat exchanger. As the water exchanges heat with the refrigerant, the water is heated in the heat sink, exits the heat sink, and flows into the hot reservoir of the storage tank. During a water discharge mode, the hot water in the hot reservoir is removed from the storage tank and flows into a hot water discharge. Cold water from a water source flows into the cold reservoir of the storage tank to refill the storage tank.

Abstract: A bottle cooler system includes means for using atmospheric water condensate from the evaporator to draw heat from the condenser.

Abstract: Refrigerant is circulated through an economized refrigeration system including a compressor, a gas cooler, a main expansion device, an economizer heat exchanger and an evaporator. After cooling, the refrigerant splits into an economizer flow path and a main flow path. Refrigerant in the economizer flow path is expanded to a low pressure and exchanges heat with the refrigerant in the main flow path in the economizer heat exchanger. The refrigerant in the main flow path is then expanded and heated in the evaporator and enters the compressor, completing the cycle. An accumulator positioned between the economizer heat exchanger and the compressor stores excess refrigerant in the system, regulating the amount of refrigerant in the system and the high pressure in the system. The amount of refrigerant in the accumulator is controlled by regulating the economizer expansion device.

Abstract: An expensive expansion device may be eliminated in favor of a less expensive pressure regulator in a CO2 vapor compression system such as is used in a bottle cooler or small-capacity air conditioner, refrigerator, or other system.

Abstract: A refrigeration system includes a compressor for driving a refrigerant along a flow path in at least a first mode of system operation; a first heat exchanger along the flow path downstream of the compressor in the first mode; a second heat exchanger along the flow path upstream of the compressor in the first mode; and an expansion device in the flow path downstream of the first heat exchanger and upstream of the second heat exchanger in the first mode, wherein the second heat exchanger includes a combined header and accumulator for collecting liquid and vapor refrigerant.

Abstract: A refrigeration system includes 0 compressor for driving 0 refrigerant along flow path in at least a first mode of system; a first heat exchanger along the flow path downstream of the compressor in the first mode; a second heat exchanger along the flow path upstream the compressor in the first mode; and a pressure regulator or expansion device in the flow path downstream of the first heat exchanger and upstream of the second heat exchanger in the first mode, wherein at least one of the first heat exchanger and the second heat exchanger comprises a flat tube heat exchanger.

Abstract: A refrigeration system includes a compressor for driving a refrigerant along a flow path in at least a first mode of system operation; a first heat exchanger along the flow path downstream of the compressor in the first mode; a second heat exchanger along the flow path upstream of the compressor in the first mode; and a pressure regulator or expansion device in the flow path downstream of the first heat exchanger and upstream of the second heat exchanger in the first mode, wherein the first heat exchanger is positioned within a housing which defines a flow path for heat exchange fluid and the housing defines a zone of reduced flow area along the flow path, and wherein the first heat exchanger is positioned in the zone of reduced flow area.

Abstract: A refrigeration system includes a compressor for driving a refrigerant along a flow path in at least a first mode of system operation; a first heat exchanger along the flow path downstream of the compressor in the first mode; a second heat exchanger along the flow path upstream of the compressor in the first mode; and a pressure regulator or expansion device in the flow path downstream of the first heat exchanger and upstream of the second heat exchanger in the first mode, wherein the first heat exchanger comprises a plurality of heat exchanger components arranged along a flow path of heat exchange fluid for the first heat exchanger. The heat exchanger components can be positioned in smaller available areas within the unit and thereby use space more efficiently.

Abstract: A bottle cooler system (20, 70, 100) includes a compressor (22), a first heat exchanger (24) and a second heat exchanger (28). In a cooling mode of operation, the second heat exchanger is downstream of the first heat exchanger and upstream of the compressor to cool contents of an interior volume. In a defrost mode of operation, refrigerant in the second heat exchanger is used to defrost an ice build-up on the second heat exchanger.

Abstract: A refrigeration system (20) includes a pressure addition relief valve (62) in parallel with an expansion device (63).

Abstract: A refrigerant cycle is provided with a control for an expansion device to achieve a desired compressor discharge pressure. The system operates transcritically, such that greater freedom over compressor discharge pressure is provided. The system's efficiency is optimized by selecting an optimum discharge pressure. The optimum discharge pressure is selected based upon sensed environmental conditions, and the expansion device is adjusted to achieve the desired compressor discharge pressure. A feedback loop may be provided to sense the actual compressor discharge pressure and adjust the actual compressor discharge pressure by further refining the expansion device. The system is disclosed providing heated water based upon a demand for a particular hot water temperature.

Abstract: A refrigerant cycle is provided with a single three-way service valve that is utilized for draining and adding refrigerant. In the prior art, a second two-way valve was used in combination with the three-way valve. The present invention simply drains the refrigerant, and does not need to return the refrigerant. The present invention is particularly well suited for use with an environmentally benign refrigerant such as CO2.

Abstract: A thermoelectric effects materials based energy transduction device, for selectively providing conversions between electrical and thermal energies having interleaved n-type conductivity material layers having thermoelectric effects properties and a first plurality of p-type conductivity material layers each having thermoelectric effects properties. There is a first plurality of passageway structures each being thermally conductive and each having passageways therethrough extending between two sides thereof with such a passageway structure from this first plurality thereof positioned between members of each overlapped pair of succeeding layers.

Abstract: A heat pump, and in particular a heat pump for heating a hot water supply is provided with an improved defrost mode. The defrost mode is actuated to remove frost from an outdoor evaporator that may accumulate during cold weather operation. An algorithm for operation of the defrost mode is developed experimentally by seeking to maximize the heat transfer provided by the refrigerant. A heating system condition is experimentally related to the heat transfer capacity. One then maximizes the average heat transfer capacity to determine the optimum initiation point for the defrost mode. Further, protections are included into the defrost mode. When the heat pump is utilized to heat hot water, methods are provided to prevent the water that remains in the heat exchanger from becoming unduly heated. In one method, the water pump may be periodically operated to move the water.

Abstract: A vapor compression system includes a compressor, a gas cooler, an expansion device, and an evaporator. Refrigerant is circulated through the system. The high side pressure of the vapor compression system is selected to optimize the heating capacity. In one example, the optimal high side pressure is obtained by determining the high side pressure that correlates to the maximum current required to operate to the water pump. In another example, the actual temperature of the water entering the gas cooler, the water exiting the gas cooler, and the ambient air temperature are measured and compared to a predetermined value to determine the optimal high side pressure.

Abstract: An accumulator acts as a buffer to prevent over-pressurization of the vapor compression system while inactive. By determining the maximum storage temperature and the maximum storage pressure a system will be subject to when inactive, a density of the refrigerant for the overall system can be calculated. Dividing the density by the mass of the refrigerant determines an optimal overall system volume. The volume of the components is subtracted from the overall system volume to calculate the optimal accumulator volume. The optimal accumulator volume is used to size the accumulator so that the accumulator has enough volume to prevent over-pressurization of the system when inactive.