Abstract: A refrigeration system includes: a compressor arrangement for compressing gaseous refrigerant from a first pressure to a second pressure, wherein the second pressure comprises a condensing pressure; a first condenser evaporator system and a second condenser evaporator system, where in the first condenser evaporator system and the second condenser evaporator system are arranged in parallel and each comprises: (1) a condenser for receiving gaseous refrigerant at a condensing pressure and condensing the refrigerant to a liquid refrigerant, where in the condenser comprises a gaseous refrigerant inlet, a plate and a liquid refrigerant outlet, and a water delivery system for delivering water to an outside of the plate for removing heat from the plate; (2) a controlled pressure receiver for holding the liquid refrigerant from the condenser; and (3) an evaporator for evaporating the liquid refrigerant from the controlled pressure receiver to form the gaseous refrigerant; a first gaseous refrigerant feed line for feed

Abstract: During heat applying operation, both an air-source heat exchanger that exchanges heat with the atmosphere as a heat source and an earth-source heat exchanger that uses geothermal heat as a heat source serve as evaporators to collect heat from the atmosphere and the geothermal heat. During defrosting operation, while a four-way valve is switched to cause the air-source heat exchanger to serve as a radiator, and the earth-source heat exchanger to serve as an evaporator to collect the geothermal heat, and the collected geothermal heat is collected in the main circuit via the sub-circuit.

Abstract: An improved vent ice prevention apparatus including a first conduit, a second conduit, and a third conduit, wherein the second conduit concentrically surrounds the first conduit thereby forming an annular region between the two conduits. The third conduit is in fluid communication with said annular region. The first conduit is configured to receive a cold vent stream, and the third conduit is configured to receive a dry purge stream and introduce the dry purge stream into the annular region in order to prevent ice formation.

Abstract: An improved vent ice prevention method including introducing a cold vent stream into a first conduit, wherein at least a portion of the first conduit is concentric with a second conduit, thereby producing an annular region, introducing a hot vent stream into a third conduit, and wherein the third conduit is in fluid connection with the annular region, thereby preventing the first conduit or the second conduit from forming ice. The cold vent stream is a cold compressor seal vent stream. The hot vent stream is a warm compressor seal vent stream.

Abstract: A control method for a heat pump system, or for a motor vehicle, which includes a compressor, an internal heat exchanger forming a condenser in a heating mode, an expansion valve, an outer heat exchanger forming an evaporator in the heating mode, and an accumulator. The defrosting of the outer exchanger is detected, the defrosting of the accumulator is detected, and depending on the case, defrosting the outer exchanger and/or defrosting the accumulator is started.

Abstract: The invention relates to an air-conditioning loop for heating, ventilation, and/or air-conditioning equipment in which a coolant circulates. The loop including a compressor comprising a coolant outlet connected to a delivery pipe and a coolant inlet connected to a suction pipe. The loop also including an internal heat exchanger which is capable of functioning at least as a condenser, and which is connected to the compressor via the delivery pipe. The loop also including an external unit which is connected to the compressor via the suction pipe and which includes at least one external heat exchanger capable of functioning at least as an evaporator, with the internal heat exchanger being connected to the external unit via a first intermediate duct comprising at least one pressure-release member. The loop includes a deicing pipe connected to the compressor and/or to the delivery pipe, as well as to the external unit.

Abstract: The present disclosure, in one embodiment, relates to a defrosting apparatus comprising a manifold, wherein the manifold is adapted to expel a liquid onto an evaporator component. The apparatus further comprising one or more cold liquid pipes adapted to deliver the liquid to a container, the container comprising a mechanism for heating the liquid. And the apparatus also comprising one or more heated liquid pipes adapted to deliver the liquid from the container to the manifold. The present disclosure includes a computer with tactile monitor, machine vision, video cameras for inspecting, reporting and acting to defrost the freezer evaporator(s), and WiFi capabilities. Freezer access and inventory tracking is controlled by a second camera built onto the outward facing tactile monitor. Facial, pattern, and voice recognition is built into this device to provide reliable security and inventory control.

Abstract: Heat pumps with improved defrost cycles and methods of defrosting heat exchangers, for example, having microchannel outdoor heat exchangers. A heat exchanger has three types of connection points that are used during a defrost cycle. Two connection points are used to deliver hot refrigerant gas to the heat exchanger and one connection point is where refrigerant exits the heat exchanger. Two of the connection points are at the same header and during at least part of the defrost cycle, at least part of the hot refrigerant gas is passed through that header without passing through any cross tubes of the heat exchanger. A defrost valve in a refrigerant conduit opens during the defrost cycle to deliver hot refrigerant gas to the connection point on the header. In a number of embodiments, the defrost valve is open only during a portion of the defrost cycle.

Abstract: Systems and methods are disclosed for water collection from atmospheric moisture in large quantities in uncontrolled outdoor environments where the temperature may be cold and humidity levels low. To extract water from air when the dew point is low, a heat exchanger cools to a point where water vapor is deposited on its surface as ice. The heat exchanger then cycles through a heating phase to melt the ice and generate liquid water. The accumulation of frost is advantageous. Frost accumulation enables water collection when the dew point is low. Disclosed variations enhance efficiency and environmental tolerance.

Abstract: Systems and methods for low ambient air temperature cooling in air-source based heat pump systems wherein an outdoor heat pump unit includes a discharge hood positionable over its fan. The hood including a damper that is openable and closeable as a function of outside temperature. The outdoor unit may also include wind deflectors positioned over the coil openings of the disclosure. During cooling operations below a low outside air threshold temperature, e.g., below 23° F., the damper assembly partially closes to reduce airflow across the condenser coil of the outdoor unit to a level below that which is possible at minimum fan speed. As the outdoor temperature continues to drop, the damper assembly continues to close to further reduce airflow.

Abstract: A cascade refrigeration system using a first refrigerant or a high stage and a second, R-744, refrigerant for low stage refrigeration has a defrost system including a defrost compressor, a defrost inlet heat exchanger and defrost outlet heat exchanger. The defrost inlet heat exchanger receives a defrost portion of second refrigerant and adds an additional defrost heat load thereto from first refrigerant, thus evaporating defrost portion. Defrost portion is then compressed into high pressure defrost vapor portion in the defrost compressor. The defrost vapor portion is then circulated through a selected evaporator, where a defrost heat, augmented by additional defrost heat load, defrosts selected evaporator, defrost vapor being at least partially condensed into defrost condensed portion which is liquefied in defrost outlet heat exchanger.

Abstract: Heat pumps with improved defrost cycles and methods of defrosting heat exchangers, for example, having microchannel outdoor heat exchangers. A heat exchanger has three types of connection points that are used during a defrost cycle. Two connection points are used to deliver hot refrigerant gas to the heat exchanger and one connection point is where refrigerant exits the heat exchanger. Two of the connection points are at the same header and during at least part of the defrost cycle, at least part of the hot refrigerant gas is passed through that header without passing through any cross tubes of the heat exchanger. A defrost valve in a refrigerant conduit opens during the defrost cycle to deliver hot refrigerant gas to the connection point on the header. In a number of embodiments, the defrost valve is open only during a portion of the defrost cycle.

Abstract: Disclosed is a unitary heat pump air conditioner (HPAC) system having a refrigerant diversion loop configured to supply sufficient heat to defrost an external heat exchanger while not materially affecting the supply of heat to the passenger compartment of a vehicle. The HPAC system includes a refrigerant loop configured to pump heat from a cold coolant loop that scavenges heat from the external heat exchanger to a hot coolant loop that supplies heat to the passenger compartment. The refrigerant loop includes a condenser in thermal communication with the hot coolant loop, evaporator in thermal communication with the cold coolant loop, and a compressor to cycle the refrigerant through the refrigerant loop. The refrigerant loop further includes means to selectively divert at least a portion of the hot compressed refrigerant exiting the compressor directly to the evaporator to heat the cold coolant loop sufficient to defrost the external heat exchanger.

Abstract: A condenser evaporator system includes: a condenser constructed for condensing a gaseous refrigerant from the source of compressed gaseous refrigerant; a controlled pressure receiver for holding liquid refrigerant; a first liquid refrigerant feed line for conveying liquid refrigerant from the condenser to the controlled pressure receiver; an evaporator for evaporating liquid refrigerant; and a second liquid refrigerant feed line for conveying liquid refrigerant from the controlled pressure receiver to the evaporator. The condenser evaporator system can be provided as multiple condenser evaporator systems operating from a source of compressed gaseous refrigerant.

Abstract: Adaptable evaporator defrost logic is employed in a refrigeration system to detect a build-up of ice on the evaporator. In response to the detected build-up of ice, a defrost operation is initiated that includes decreasing the speed of the compressor. At the end of the defrost operation, the adaptable evaporator defrost logic determines whether the defrost operation was a success. If the defrost operation was a success, then normal operation is resumed. If the defrost operation was not a success, then the defrost operation is modified by turning the compressor off and extending a duration of the defrost operation.

Abstract: A system, configured to be disposed in a information technology equipment rack for providing ice thermal storage, includes a tank configured to hold water, a heat exchanger disposed in water in the tank and configured to convey a two-phase liquid and vapor refrigerant and to transfer heat between the water and the refrigerant, a first valve connected to a liquid and a vapor refrigerant line and configured to selectively connect the liquid refrigerant line to a first port and the vapor refrigerant line to a second port in a first mode and to connect the liquid refrigerant line to the second port and the vapor refrigerant line to the first port in a second mode, a thermostatic expansion valve connected to an inlet of the heat exchanger, and a liquid/vapor pump connected to an outlet of the heat exchanger and to the second port of the first valve.

Abstract: Heat pumps with improved defrost cycles and methods of defrosting heat exchangers, for example, having microchannel outdoor heat exchangers. A heat exchanger has three types of connection points that are used during a defrost cycle. Two connection points are used to deliver hot refrigerant gas to the heat exchanger and one connection point is where refrigerant exits the heat exchanger. Two of the connection points are at the same header and during at least part of the defrost cycle, at least part of the hot refrigerant gas is passed through that header without passing through any cross tubes of the heat exchanger. A defrost valve in a refrigerant conduit opens during the defrost cycle to deliver hot refrigerant gas to the connection point on the header. In a number of embodiments, the defrost valve is open only during a portion of the defrost cycle.

Abstract: Heat pumps with improved defrost cycles, methods of defrosting heat exchangers, and methods of improving the effectiveness of defrost cycles of heat pumps, for example, having a microchannel outdoor heat exchanger. A defrost valve in a refrigerant conduit opens during a defrost cycle to deliver hot refrigerant gas to a portion of the heat exchanger that otherwise defrosts more slowly or less completely than other portions of the heat exchanger. Particular embodiments pass hot refrigerant gas through a header of the heat exchanger, such as a bottom header. In a number of embodiments, the defrost valve is open only during a portion of the defrost cycle. Further, in some embodiments, the fan that is used to blow air through the heat exchanger is operated in a reversed direction during at least part of the defrost cycle to counteract natural convection through the heat exchanger.

Abstract: A vapour compression refrigeration system includes a compressor (1) arranged to re-circulate refrigerant through a condenser (2), an expansion device (4) and an evaporator (5). To achieve rapid thermodynamically efficient defrosting of the evaporator, hot refrigerant from the condenser is stored in a defrost receiver (6) before passing through the expansion device (4). In a defrost phase, a valve arrangement (7-10) forms a closed defrost circuit connecting the evaporator (5) to the defrost receiver (6) via defrost valve (10) to allow hot fluid to pass from the defrost receiver to the evaporator and liquid refrigerant in the evaporator flows to the defrost receiver (6) via drain valve (9). In a pre-defrost phase, the valve arrangement closes the fluid input to the evaporator (5) and the compressor operates to partially evacuate the evaporator before the evaporator is connected to the defrost receiver, so that flash flooding of the evaporator with hot vapour occurs.

Abstract: A method for reducing perceived defrost noise in a heat pump is provided. The method may include energizing a fan configured to urge a heat transfer medium across a heat exchanger, and initiating a defrost cycle to warm the heat exchanger. Initiating the defrost cycle may include de-energizing a compressor fluidly coupled to the heat exchanger, and delaying for a first delay period with the fan energized and the compressor de-energized. Initiating the defrost cycle may also include energizing a reversing valve after the first delay period, to reverse a flow of a refrigerant flow between the compressor and the heat exchanger, and delaying for a second delay period with the fan energized, the compressor de-energized, and the reversing valve energized. Initiating the defrost cycle may also include de-energizing the fan. The method may also include defrosting the heat pump during the defrost cycle, and terminating the defrost cycle.

Abstract: An air conditioner is provided, in which some of a plurality of outdoor heat exchangers implement a defrosting operation and others implement a heating operation. The air conditioner includes a compressor to compress refrigerant, a hot gas pipe to which a part of the refrigerant compressed in the compressor is moved, a 4-way valve to which the remaining refrigerant compressed in the compressor is moved, an indoor heat exchanger in which the refrigerant, having passed through the 4-way valve, undergoes heat exchange with indoor air, and a plurality of outdoor heat exchangers, some of which implement a heating operation as the heat-exchanged refrigerant from the indoor heat exchanger is moved therethrough while others implement a defrosting operation as the refrigerant having passed through the hot gas pipe is moved therethrough.

Abstract: A condenser evaporator system includes: a condenser constructed for condensing a gaseous refrigerant from the source of compressed gaseous refrigerant; a controlled pressure receiver for holding liquid refrigerant; a first liquid refrigerant feed line for conveying liquid refrigerant from the condenser to the controlled pressure receiver; an evaporator for evaporating liquid refrigerant; and a second liquid refrigerant feed line for conveying liquid refrigerant from the controlled pressure receiver to the evaporator. The condenser evaporator system can be provided as multiple condenser evaporator systems operating from a source of compressed gaseous refrigerant.

Abstract: An air conditioner (1) includes: a compressor (21); an outdoor heat exchanger (23); an indoor heat exchanger (13); an outdoor fan (25); and an indoor fan (15). In a case where the outdoor heat exchanger (23) has frost, the indoor fan (15) and the outdoor fan (25) are stopped, and a refrigerant is flowed in a direction opposite to a warming operation so as to perform a defrosting operation. In a case where a temperature of the refrigerant output from the compressor (21) declines below a predetermined temperature during the defrosting operation, it is determined to be defective defrosting. In a case of the defective defrosting by the defrosting operation, the outdoor fan (25) is driven, the indoor fan (15) is stopped and the refrigerant is flowed in a same direction as the warming operation so as to perform a defrosting preparation operation. Thereafter, the defrosting operation is resumed.

Abstract: Surged heat pump systems, devices, and methods are disclosed having refrigerant phase separators that generate at least one surge of vapor phase refrigerant into the inlet of an evaporator during an on cycle of the compressor. This surge of vapor phase refrigerant, having a higher temperature than the liquid phase refrigerant, increases the temperature of the evaporator inlet, thus reducing frost build up in relation to conventional refrigeration systems lacking a surged input of vapor phase refrigerant to the evaporator. The temperature of the vapor phase refrigerant is raised in relation to the liquid phase with heat from the liquid by the phase separation, not by the introduction of energy from another source. The surged heat pump systems may operate in highest heat transfer efficiency mode and/or in one or more higher temperature modes.

Abstract: A refrigerator and a control method of the same are disclosed. A refrigerator includes a plurality of evaporators and a refrigerant path conversion device connected with the plurality of the evaporates, the refrigerant path conversion device controlling a path of refrigerant to perform defrosting operations for predetermined evaporators and cooling operations for the other evaporators.

Abstract: Methods and apparatus for an energy efficient freezer or cooler defrost, which are particularly suited for an automated system, include procedures utilized for this purpose. The procedures are included in the firmware of an embedded controller and operate the cooler or freezer defrost cycle when required for increased energy efficiency.

Abstract: A refrigerant cycle (16) for cooling as a prototype is provided with: an internal condenser (8) connected to a discharge circuit of an electric compressor (9) and disposed on a downstream of an internal evaporator (7) of an HVAC unit (2); a first heating circuit (18) connected to a receiver (11) through a switching unit (17) arranged on an inlet side of the external condenser (8); and a second heating circuit (23) connected between an outlet side of the receiver (11) and a suction side of the electric compressor (9) and provided with a second expansion valve (20) and an external evaporator (21). A heat pump cycle (24) for heating is formed by a second heating circuit (23) including the electric compressor (9), the internal condenser (8), the switching unit (17), the first heating circuit (18), the receiver (11), the second expansion valve (20), and the external evaporator (21).

Abstract: A method of defrosting an energy recovery ventilator unit. The method comprises activating a defrost process of an enthalpy-exchange zone of the energy recovery ventilator unit when an air-flow blockage in the enthalpy-exchange zone coincides with a frost threshold in the ambient environment surrounding the energy recovery ventilator unit. The method also comprises terminating the defrost process, including terminating the defrost process when an operating condition in the vicinity of the enthalpy-exchange zone substantially returns to a pre-frosting operating condition.

Abstract: A high performance refrigerator includes a cabinet with a unitary refrigerated interior and a refrigeration fluid circuit having first and second evaporators located within the cabinet and separated from the refrigerated interior by respective first and second evaporator covers. The refrigerator also includes a first damper controlling flow between the first evaporator and the refrigerated interior, and a second damper controlling flow between the second evaporator and the refrigerated interior. A controller directs the refrigerator to operate a three-way valve in the refrigeration fluid circuit so as to direct refrigerant to only one of the evaporators when the other requires defrosting. Both evaporators may be used to remove heat from the unitary refrigerated interior during an initial cooling or immediately after the cabinet is opened.

Abstract: An air conditioner is provided. The air conditioner includes: an outdoor heat exchange unit in which a plurality of refrigerant tubes are disposed to be separated in a plurality of columns in a vertical direction to exchange heat of outdoor air and a refrigerant; a first refrigerant distribution device having branch pipes connected to a plurality of refrigerant tubes, respectively, of an upper part among the plurality of refrigerant tubes; a second refrigerant distribution device having branch pipes connected to a plurality of refrigerant tubes, respectively, of a lower part among the plurality of refrigerant tubes; and a communication pipe for communicating one of the branch pipes of the first refrigerant distribution device and one of the branch pipes of the second refrigerant distribution device.

Abstract: The present invention provides an energy efficient air conditioner that can provide a continuous supply of air at dew point that is several degrees Celsius below zero, without requiring a defrost cycle. The air conditioner in accordance to present invention comprises a plurality of cooling coils with interconnecting refrigerant piping, refrigeration circuit consisting of compressor and condenser coils, control circuit and one or more electric motor driven centrifugal fan. The present invention uses two cooling systems. The first cooling system having single coil cools the air to a temperature just above zero deg. C., say four deg. C. so that the second stage gets a steady supply of cold air. The second stage has two coils, each being half the size of the first stage coil, thus taking half the air from it so that all the air from stage 1 passes through stage 2. In operation, only one coil of the second stage is active arid chills the air going through it to say minus 14 Deg. C.

Abstract: A method of defrosting a transcritical vapor compression system having a compressor for compressing a refrigerant, a first heat exchanger for cooling the refrigerant during a cooling mode, an expansion valve for decreasing the pressure of the refrigerant, and a second heat exchanger for cooling a space during the cooling mode. The method includes attaining a superheated refrigerant condition in a defrost mode of the transcritical vapor compression system and defrosting the second heat exchanger in the defrost mode by directing the superheated refrigerant to the second heat exchanger without bypassing the first heat exchanger.

Abstract: A condenser evaporator system includes: a condenser constructed for condensing a gaseous refrigerant from the source of compressed gaseous refrigerant; a controlled pressure receiver for holding liquid refrigerant; a first liquid refrigerant feed line for conveying liquid refrigerant from the condenser to the controlled pressure receiver; an evaporator for evaporating liquid refrigerant; and a second liquid refrigerant feed line for conveying liquid refrigerant from the controlled pressure receiver to the evaporator. The condenser evaporator system can be provided as multiple condenser evaporator systems operating from a source of compressed gaseous refrigerant.

Abstract: A water-cooled air conditioner is provided, and includes an indoor unit, an outdoor unit, a cooling tower, and a boiler. The indoor unit cools or heats a space, and includes a first heat exchanger that performs heat exchange between air and refrigerant. The outdoor unit is installed separately from the indoor unit and includes a second heat exchanger that performs heat exchange between water and refrigerant. The cooling tower is connected to the outdoor unit, and cools water flowing to the second heat exchanger. The boiler is connected to the outdoor unit, and increases a temperature of the water flowing to the second heat exchanger. The second heat exchanger is formed with a plurality of thin plates separated from one another by predetermined gaps through which refrigerant and water flow. The second heat exchanger includes an anti-freezing device that prevents freezing of water within the second heat exchanger.

Abstract: An appliance includes a compression stage, a condensation stage, and an evaporation stage. The evaporation stage includes a first evaporator for a first refrigerated enclosure and a second evaporator for a second refrigerated enclosure. A first valve in a condensation stage bypass line is openable to allow a supply of refrigerant to bypass the condensation stage during a defrost mode, where a condensation stage bypass line is positioned between an output of the compression stage and the second evaporator. A second valve is positioned in a line from the second evaporator to the input to the compression stage and is closeable to block a supply of refrigerant from the second evaporator to the compression stage during the defrost mode. An additional line positioned between the second evaporator and the first evaporator carries the supply of refrigerant from the second evaporator to the first evaporator in the defrost mode.

Abstract: A heater is provided for elevating the temperature of a surface of a refrigerator above the dew point of air surrounding the surface so as to avoid condensation. Heat energy is recovered from the refrigeration cycle of the refrigerator by using a portion of the appliance's refrigeration loop to provide heat to the desired surface. A conductive element is connected with the desired surface and also placed into contact with a heated portion of the refrigeration loop to conduct heat energy therebetween. The surface and conductive element may be selectively removed and replaced from the refrigerator without the use of electric heating elements as conventionally required for removable surfaces.

Abstract: A heat pump includes a valve system that connects a receiver tank in fluid communication with an indoor heat exchanger, wherein the valve system, operating under a novel control scheme, works in conjunction with the receiver to control the heat pump's effective refrigerant charge. To avoid suction or discharge pressure faults and to help prevent slugs of liquid refrigerant from entering the heat pump's compressor as the heat pump switches between heating and cooling modes or switches between heating and defrost modes, the control scheme provides momentary periods of transition between those modes of operation. In some embodiments, the valve system comprises a check valve connected in parallel flow relationship with a two-position receiver valve, wherein the check valve has an appreciably higher flow coefficient than that of the receiver valve.

Abstract: A method of conditioning air in a vehicle load space. The method includes providing a refrigeration circuit including an evaporator, directing refrigerant through the refrigeration circuit, directing load space air across the evaporator, sensing a first condition based on one of a temperature and a pressure of the refrigerant in the refrigeration circuit upstream from the evaporator, determining a second condition based on one of a temperature and a pressure of the refrigerant in the evaporator, determining a difference between the first condition and the second condition, and initiating a defrost process of the evaporator when the difference is greater than a threshold.

Abstract: A CO2 refrigeration system comprises a refrigeration circuit in which circulates CO2 refrigerant between a compression stage in which the CO2 refrigerant is compressed. A condensation stage is provided in which the CO2 refrigerant releases heat and is accumulated in a condensation reservoir. An evaporation stage is provided in which the CO2 refrigerant is expanded to a gaseous state to absorb heat from a fluid for refrigeration, with at least a portion of CO2 refrigerant exiting the evaporation stage being directed to a supra-compression circuit comprising a supra-compression stage in which the portion of CO2 refrigerant is compressed. A heat exchanger is provided by which the compressed CO2 refrigerant is in a heat-exchange relation with a secondary-refrigerant circuit, such that the compressed CO2 refrigerant releases heat to a secondary refrigerant used for heating purposes. Pressure-regulating means control a pressure of the compressed CO2 refrigerant being returned to the condensation stage.

Abstract: Systems and methods for low ambient air temperature cooling in air-source based heat pump systems wherein an outdoor heat pump unit includes a discharge hood positionable over its fan. The hood including a damper that is openable and closeable as a function of outside temperature. The outdoor unit may also include wind deflectors positioned over the coil openings of the disclosure. During cooling operations below a low outside air threshold temperature, e.g., below 23° F., the damper assembly partially closes to reduce airflow across the condenser coil of the outdoor unit to a level below that which is possible at minimum fan speed. As the outdoor temperature continues to drop, the damper assembly continues to close to further reduce airflow.

Abstract: A control method includes determining whether to perform a defrosting operation of an evaporator, closing a valve to prevent refrigerant from moving into the evaporator if implementation of the defrosting operation is determined, performing a refrigerant collecting operation, and opening the valve upon completion of the defrosting operation. Intercepting a flow path of the refrigerant to prevent the refrigerant from moving into the evaporator during defrosting prevents explosion due to leakage of the refrigerant.

Abstract: A refrigeration device containing CO2 a refrigerant to be circulated, including a compressor, a heat-rejecting heat exchanger, an expansion, and an evaporator which are connected to one another. The refrigeration device includes a first portion and a second portion, the second portion having a higher temperature relative to the first portion when the refrigeration device is in operation. A heat-reclaim heat exchanger is 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: An icemaker moisture removal and defrost assembly is provided in a refrigerator. Cooled refrigerant is provided to a refrigerant loop within an icemaker to cool an ice making cavity and a moisture removal portion of the icemaker. Moisture laden air from a refrigerator compartment is directed through airflow channels defined by a plurality of fins extending from the moisture removal portion of the icemaker, whereby moisture condenses on the fins in the form of ice. Dry air exiting the airflow channels is directed across an evaporator and back into the refrigerator compartment. During a defrost event, a heater within the icemaker is used to melt the ice formed on the fins. Alternatively, hot gas from a compressor is used to heat a refrigerant line flowing through the evaporator and/or the icemaker to melt ice formed on the evaporator and/or the icemaker during a defrost event.

Abstract: A freezer that uses liquid cryogen as a refrigerant includes an inner vessel defining a storage chamber and an outer jacket generally surrounding the inner vessel so that an insulation space is defined there between. A heat exchanger is positioned in a top portion of the storage chamber and has an inlet in communication with a supply of the liquid cryogen refrigerant so that the liquid cryogen refrigerant selectively flows through the heat exchanger to cool the storage chamber while being vaporized. A purge line is in communication with the outlet of the heat exchanger and includes a purge outlet positioned over the exterior of the heat exchanger. A purge valve is positioned within the purge line so that the vaporized liquid cryogen from the heat exchanger is selectively directed to the exterior of the heat exchanger to reduce ice formation on the heat exchanger.

Abstract: Method for defrosting an evaporator in a refrigeration circuit (2) for circulating a refrigerant in a predetermined flow direction, the refrigeration circuit (2) comprising in flow direction a compressor unit (4), a heat-rejecting heat exchanger (6), an expansion device (12) and an evaporator (14), wherein the evaporator (14) comprises at least two refrigerant conduits (42; 44) and the method comprises the following steps: (a) operating the refrigeration circuit (2) in the normal cooling mode where the refrigerant exiting the heat-rejecting heat exchanger (6) flows through the expansion device (12) and through the evaporator (14) and towards the compressor unit (4); (b) terminating the cooling mode by interrupting the flow of the refrigerant exiting the heat-rejecting heat exchanger (6) into the evaporator (14); and (c) directing hot gas refrigerant through only a portion of the refrigerant conduits (42; 44) of the evaporator (14) for defrosting the evaporator (14).

Abstract: A heat pump is provided with an improvement while switching from heating/cooling mode to a defrost mode. Prior to initiation of a defrost mode, an electronic expansion device is moved to an open position such that refrigerant can migrate between the indoor-outdoor heat exchangers. When the operation of the defrost cycle is initiated, there is a lower likelihood and severity of flooded starts, as the refrigerant, under existing pressure differential at system shutdown, will move to the heat exchanger that will be downstream of the compressor in the defrost mode. Thus, no flooded start will occur on the subsequent compressor start-up. After completion of the defrost cycle, the electronic expansion device is again opened prior to return to operation in the conventional heating/cooling mode. In case subsequent starts are in an identical mode of operation, the electronic expansion valve is kept closed during shutdown to minimize cyclic performance losses.

Abstract: The present invention relates to a device and method for operating a refrigeration cycle with the addition of noncondensable gas.

Abstract: An adaptive defrost control for a frozen product machine implements an algorithm that utilizes various operating parameters of the machine to adaptively adjust the time interval between successive defrost cycles in a manner such that defrost cycles occur only on an as-needed basis. The adaptive defrost control minimizes the time during which the machine is in a defrost cycle, thereby maximizing the uptime of the machine during which frozen product can be prepared.

Abstract: A cascade refrigeration system using a first refrigerant or a high stage and a second, R-744, refrigerant for low stage refrigeration has a defrost system including a defrost compressor, a defrost inlet heat exchanger and defrost outlet heat exchanger. The defrost inlet heat exchanger receives a defrost portion of second refrigerant and adds an additional defrost heat load thereto from first refrigerant, thus evaporating defrost portion. Defrost portion is then compressed into high pressure defrost vapor potion in the defrost compressor. The defrost vapor portion is then circulated through a selected evaporator, where a defrost heat, augmented by additional defrost heat load, defrosts selected evaporator, defrost vapor being at least partially condensed into defrost condensed portion which is liquefied in defrost outlet heat exchanger.

Abstract: A self-contained air-conditioning unit is modified to effect conservation of energy during operation of the unit. Refrigerant is moved along a refrigerant circuit for circulation through a compressor, a condenser and an evaporator within a housing which includes a base. The evaporator is raised above the base a distance sufficient to enable collection of condensate from the evaporator and transfer of the collected condensate by gravity to a condensate reservoir tray located adjacent the base. A heat exchange conduit is inserted into the refrigerant circuit, between the compressor and the condenser, and is placed in the condensate reservoir tray so as to be immersed in the condensate transferred to the condensate reservoir tray for enabling transfer of heat from the heat exchange conduit to condensate in the condensate reservoir tray during operation of the air-conditioning unit, thereby reducing the amount of energy needed to operate the unit.