Abstract: A method for controlling an air-conditioning apparatus in terms of execution of the defrosting mode. The apparatus basically includes a variable-frequency compressor, a room heat-exchanger for performing heat-exchange with a room fan, and an outdoor heat-exchanger provided at the outside of the room, which are circularly coupled to each other to establish a refrigerating cycle. Also included in the air conditioning apparatus are a bypass circuit provided between a first line for effecting a connection between an outlet side of the compressor and the room heat-exchanger and a second line for effecting a connection between an inlet side of the compressor and the outdoor heat-exchanger and a restriction device arranged to allow a change of its restriction amount and provided between the two heat-exchanger. The bypass circuit has an opening and closing valve for shutting off the bypass circuit.

Abstract: A refrigeration system, and method of operating same, in which an economizer heat exchanger, normally used in conjunction with an intermediate port of a refrigerant compressor to cool the main refrigerant flow from a receiver to an evaporator to enhance the refrigerant cooling cycle, is caused to function as an evaporator during a hot gas heating cycle. The economizer heat exchanger is caused to function as an evaporator by adding heat thereto during a heating cycle, and by establishing an alternate liquid line, effective during a heating cycle, which includes the economizer heat exchanger. When the compressor is driven by an internal combustion engine, engine coolant may be used to add the necessary heat to the economizer heat exchanger during a heating cycle.

Abstract: A refrigeration system comprises a plurality of evaporators and a plurality of conduits for feeding cooling-medium vapor evaporated in the evaporators to a plurality of compressors having a common outlet header for compression therein. Conduits extends between the common outlet header of the compressors and the inlets of the evaporators to feed the heated cooling-medium vapor produced by the compressors to one, several or all of the evaporators for defrosting the same.

Abstract: An air conditioner having a defrosting mode of operation is disclosed, in which an outdoor heat exchanger is divided into two heat exchanger units juxtaposed in tandem with each other along the direction of air passage. In defrosting mode, a part of the refrigerant from the compressor is supplied to the upstream outdoor heat exchanger unit deposited with frost, and the rest of the high-temperature high-pressure refrigerant is supplied to the indoor heat exchanger to maintain the room temperature.

Abstract: This invention relates to a cooling and heating system which operates on the absorption and phase change heat exchange principle. More particularly it relates to a continuous heat actuated, air cooled, double effect generator cycle, absorption system. In further aspects, this invention relates to a system constructed for use with an absorption refrigeration solution pair consisting of a nonvolatile absorbent and a highly volatile refrigerant which is highly soluble in the absorbent. A disclosed refrigerant pair are ammonia as the refrigerant and sodium thiocyanate as the absorbent. An absorption cycle is disclosed using the thermo physical properties of sodium thiocyanate/ammonia, absorption/refrigerant pair.

Abstract: A method of enhancing the defrost and heating cycles of a transport refrigeration system for a straight truck, which refrigeration system includes a single refrigeration circuit selectively connectible to a compressor driven by the truck engine, or to a stand-by compressor driven by a motor connected to a stand-by source of electrical potential. The enhancement is achieved by slowly but continuously storing heat in an accumulator from the truck electrical system, or from the stand-by source of electrical potential, such that liquified refrigerant introduced into the accumulator during a defrost or heating cycle is immmediately vaporized. The slow but continuous rate of heat storage accumulates the requisite heat without unduly loading the truck electrical system or the truck engine.

Abstract: A refrigeration system, and a method for operating the system, having a two-stage compressor for supplying refrigerant to a cooling coil, and having a desuperheater unit disposed between the two compressor stages. This desuperheater unit includes a container having heat exchange fluid therein and a coil, disposed in the heat exchange fluid, through which the refrigerant passes. During normal operation of the refrigeration system, both compressors are running. The desuperheater unit between the two compressor stages reduces the temperature of the compressed refrigerant before it reaches the second stage. The temperature of the heat exchange fluid is correspondingly increased in the course of the heat exchange. Also during normal operation, frost accumulates on the cooling coil, which is removed by a control device initiating a defrost cycle. When the defrost cycle begins, the first stage compressor is turned off while the second stage compressor continues to run.

Abstract: An apparatus and method for providing a refrigeration circuit and for effecting defrost are disclosed. Multiple outdoor heat exchangers are utilized to effect defrost of one of the outdoor heat exchangers while the other serves as an evaporator. In the refrigeration circuit disclosed, the indoor heat exchanger is not utilized during defrost and the outdoor heat exchangers are separated such that one is defrosted while the other serves as an evaporator. The circuit may then be reversed such that the non-defrosted outdoor heat exchanger is then defrosted while the other heat exchanger serves as an evaporator. This refrigeration circuit allows for effective defrost of the outdoor heat exchangers without necessitating electric resistance heat nor the transfer of heat energy from the indoor air to the outdoor heat exchangers.

Abstract: A refrigerated display case having a defrost means which combines the supply of hot refrigerant gas to the refrigeration coils with the supply of ambient air in order to provide defrost action during a defrost cycle. The ambient air band is taken into and propelled out of the air conduit in a manner to prevent ambient air from being forced into the product display space in order to avoid thawing of the stored refrigerated products. The defrost air is ejected away from the access opening in order to allow a cold air layer to remain on top of stored products in an open top case. In front cases, a defrost air band is established across the access opening to form a protective air curtain in order to exclude the contacting of the stored products with high temperature and moist ambient air. The ambient air band is unidirectional during the entire defrost cycle.

Abstract: A closed circuit refrigeration system includes a compressor, a remote condenser connected to the output of the compressor, and one or more evaporators coupled within the system. A hot gas defrost system is included to rapidly obtain a high operating defrost gas pressure upon the initiation of a defrost cycle and to thereafter maintain an adequate pressure for hot gas defrosting of the evaporators. The hot gas defrost system includes a differential pressure regulated valve which closes the compressor discharge line to shunt the hot gas discharge directly into a hot gas defrost manifold. The differential valve is controlled by a defrost control means. The refrigeration system can also include a receiver tank and a by-pass conduit for shunting refrigerant liquid through the by-pass conduit rather than through the receiver tank depending upon operating conditions. A method of operating a closed circuit refrigeration system with the above features is set forth.

Abstract: A method and apparatus for defrosting or removing ice from the outside of the evaporator of a refrigerator or heat pump. An additional inventory of refrigerant in thermal communication with a thermal mass is pressurized to substantially the same pressure as the condenser. After the compressor is deactivated at the end of a cooling cycle, a valve separating the inventory and evaporator is opened whereby the respective pressures rapidly equalize to an intermediate pressure. The inventory of refrigerant boils in the reduced pressure thereby drawing heat from the thermal mass to support the process. The vaporized refrigerant flows through the valve to the evaporator and condenses in the relatively cool environment. The heat given off by the condensation process melts ice on the outside of the evaporator.

Abstract: Apparatus and a method for providing a combination of non-reverse and reverse defrost for a refrigeration circuit are disclosed. A three-way valve is provided for initially circulating hot gaseous refrigerant directly from the compressor to the heat exchanger requiring defrost. An intermediate header is provided as part of the internal circuiting of the outdoor heat exchanger, said intermediate header serving to direct hot gaseous refrigerant from the three-way valve into all of the circuits of the outdoor heat exchanger simultaneously to effect defrost thereof. If, after a predetermined time period, the first mode of defrost directing hot gaseous refrigerant directly to the outdoor heat exchanger fails to accomplish defrost then the three-way valve is returned to its original position and the system is operated in a second defrost mode with the reversing valve being changed such that the system operates in the cooling mode and the outdoor heat exchanger serves as a condenser until defrost is completed.

Abstract: An air cooling and water condensate removal panel has at least two interconnected capillary systems close to a plate having cooling means for removing heat from the plate. The first capillary system exists in a porous, thin outer layer having a very fine capillary structure which presents a cool, wettable surface upon which moisture in the air condenses. The outer layer is maintained cool by the cold plate. The condensate water soaks through the thin porous outer layer and is drawn into the interconnected second capillary system. The second capillary system is substantially coarser than the first system to cause the water to be drawn away more rapidly than the condensate can form upon the outer surface. The water in the coarser capillary system is drawn into a discharge pipe, preferably by employing a pump to maintain a mild vacuum in the pipe.

Abstract: A refrigeration system having an increased efficiency of operation and reduction in power consumption. Low head pressure and subcooling the liquid refrigerant emitted from the remote condenser, the efficiency of operation of the compressor of the refrigeration system can be substantially increased. The particular type of refrigeration system of concern generally includes a compressor for compressing a gaseous refrigerant, a condenser for condensing the gaseous refrigerant and subcooling the liquid refrigerant, a receiver for receiving the liquid and a plurality of display cases having evaporators for evaporating the liquid refrigerant. The gaseous refrigerant passing through the condenser is first condensed into a liquid at a condensing temperature of approximately 10.degree. to 25.degree. F. above a preselected cooling temperature. The condensed liquid is then subcooled to the preselected cooling temperature which should be preferably either approximately 50.degree. F.

Abstract: Methanol is produced by gasifying a carbonaceous feed material with steam in the presence of a carbon-alkali metal catalyst and added hydrogen and carbon monoxide at a temperature between about 1000.degree. F. and about 1500.degree. F.

Abstract: Apparatus and method for defrosting a dual refrigeration circuit refrigeration system. During defrost one of the refrigeration circuits is operated to supply heat energy to the frosted heat exchanger of the other circuit and the fan circulating heat transfer media through a heat exchanger of each circuit is reversed such that heat transfer fluid is heated by one refrigeration circuit and then used to defrost a heat exchanger of the other circuit.

Abstract: Apparatus and a method for operating a refrigeration system without reverse cycle defrost are disclosed. A heat exchanger is divided into a plurality of zones, one zone being constantly utilized as a subcooler to both defrost said zone and to subcool the refrigerant. The remaining zones of the heat exchanger are utilized as an evaporator as is known in the art. A selector valve which is capable of indexing liquid refrigerant flow between zones and receiving gaseous refrigerant from the remaining zones is also disclosed. Additionally, a header arrangement having both expansion means and a conduit controlled by check valve is utilized to direct refrigerant flow from the subcooled zones to the remaining zones of the heat exchanger which act as an evaporator.

Abstract: An improvement in refrigerated display cabinets in which barrier doors and one or more guard air bands protect the primary refrigerated air band which is circulated within the cabinets during time periods when the barrier door is opened. The cabinets may be equipped with air defrost systems. When two guard air bands are employed, the outermost of these is directed across the outside surface of the barrier door. The air defrost system can incorporate a door opening mechanism which provides a gap between the barrier door and the access opening in order to permit ambient air through-flow for defrost purposes.Control circuitry can be controlled by opening of the barrier doors in order to actuate the guard air band movement.

Abstract: A method and apparatus utilizing a hot gas defrost system wherein superheated gas from the system compressor outlet is conducted directly into the heat exchanger to be defrosted, by-passing the condenser and thermal expansion valve to effect removal of the frost and ice accumulation on the heat exchanger surface. A portion of the hot compressor discharge gas is conducted directly into an accumulator with the liquid refrigerant received from the heat exchanger to be defrosted, the liquid refrigerant resulting from the gaseous refrigerant being condensed in the heat exchanger as the ice is melted. The refrigerant condensed to a liquid during defrost is vaporized in the accumulator thereby providing a supply of gaseous refrigerant to the compressor suction line, said gaseous refrigerant being a combination of the non-condensed discharge gas conducted to the accumulator and the liquid refrigerant vaporized in the accumulator.

Abstract: Defrost of a refrigerated display case, especially those cases in which refrigerated air curtains are directed across open front or open top areas, is improved by reversing the direction of the air circulating fans during a predetermined portion of the time during which the case is in a hot gas defrost mode. In a preferred example, the evaporator fan motors are reversed following the initiation of a hot gas defrost cycle, at a time during the cycle when air warmed by the defrosting evaporator coil becomes available. A thermally actuated switch means effects the reversal at the appropriate time, so that areas of the refrigerated display case that would normally be the last to receive the benefits of the warmed air, in particular the return air flue and tank drain, become the first to be subjected to the warming effect thereof.

Abstract: A gas defrost system comprising a heat exchange assembly located in close physical proximity with a branch conduit from the compressor discharge; the branch conduit leads, through a gas manifold, to the several remote evaporators comprising the refrigeration system. Liquid refrigerant is supplied to the heat exchanger from the liquid manifold and evaporated refrigerant is returned from the heat exchanger to the suction manifold. Refrigerant flow through the heat exchanger is controlled by an externally equalized expansion valve which has sensors connected to measure the compressor discharge pressure and the defrost gas temperature downstream of the heat exchange section. The expansion valve can be preset to maintain a desired amount of heat exchange so that the temperature of the defrost gas in the manifold will be maintained at or above a predetermined lower limit.

Abstract: A method and apparatus utilizing a hot gas defrost system wherein superheated gas from the system compressor is conducted into a heat exchanger mounted within an accumulator for supplying heat to vaporize liquid refrigerant received from the evaporator. After the gas passes through the heat exchanger it is conducted to the condenser where it is condensed to a liquid and then routed to the evaporator. In the evaporator or frost accumulating coil the liquid refrigerant is subcooled, supplying heat to melt the ice formed on the evaporator surfaces and the liquid is thereafter conducted to the accumulator where the heat supplied from the heat exchanger acts to vaporize the fluid. The vaporized refrigerant is then recycled to the compressor to complete the system.

Abstract: Condensing head pressure in a refrigeration system having its condenser exposed to low outside ambient temperatures is controlled to provide the minimum head pressure required for a given mode of operation. A hierarchy of operating modes, each with its associated pressure is established, including normal refrigeration, evaporator defrost and heat reclaim. The control system prevents system head pressure from going below the minimum required for the operating mode in effect at a given time, with modes requiring higher pressure overriding lower pressure modes when required. In heat reclaim operation, high pressure gas from the compressor is diverted through a heat reclaim coil, and a subcooling sensor or other sensing means controls system head pressure to the minimum pressure that will maintain full condensing in the heat reclaim coil, which is the most economical mode of operation.

Abstract: A vertical shell and tube icemaker wherein the refrigerant surrounds tubes within which ice is made, and the freezing refrigerant outlet is positioned below the defrost refrigerant outlet to expedite release of ice during defrosting, the system employing liquid refrigerant obtained by continuous flow from the receiver for defrosting. Water is supplied around the upper ends of the tubes for maintaining a vertical stream flow which is distributed around the inner circumference of each tube.

Abstract: An air conditioning system has an evaporative cooler and a refrigerated cooler connected to a common duct connecting both of the coolers to a cooled space. A space thermostat senses space temperature of the cooled space and initiates cooling responsive thereto. A cooler selection control selects one of the coolers for cooling the cooled space responsive to the relative humidity and temperature of air outside the cooled space. The selection control delays starting of the refrigerated cooler a cool down period after the initiation of cooling. With the evaporative cooler employed in a system with, or in a system without, the refrigerated cooler, the evaporative fan is started a wetting period after the starting of the evaporative pump of the evaporative cooler to wet the evaporative pads. Additionally an exhaust vent opens when the evaporative fan of the evaporative cooler is operating and closes when the evaporative fan is stopped.

Abstract: A heat pump including an indoor heat exchanger, a main outdoor heat exchanger and an auxiliary outdoor heat exchanger provided underneath the main outdoor heat exchanger and connected between the indoor and main outdoor heat exchangers in a closed refrigerant flow circuit. The refrigerant flow circuit includes a compressor and a reversal valve which can be adjusted (1) during cooling operation to direct the hot compressed gaseous refrigerant from the compressor to the main outdoor heat exchanger and thence to the auxiliary heat exchanger acting as a sub-cooler into the indoor heat exchanger for extracting heat from air of the interior of a building and (2) during heating operation to direct the hot compressed gaseous refrigerant to the indoor heat exchanger to supply heat to the indoor air and then to the auxiliary heat exchanger now acting as a defroster for melting a block of ice which may have accumulated under the main outdoor heat exchanger and into the main outdoor heat exchanger.

Abstract: A system for refrigerating food products utilizes a saturated gaseous refrigerant, commonly called "cool gas" for defrosting an evaporator or set of evaporators. When defrost is to occur, the saturated gaseous refrigerant flows from a receiver through the evaporator or set thereof being defrosted. A differential pressure control switch operates to prevent flow of refrigerant to the receiver from the liquid supply line through which said refrigerant normally flows from the condenser to the evaporators. The flow from the liquid line to the receiver is prevented whenever the pressure in the liquid line exceeds the pressure in the receiver by a predetermined value.

Abstract: The present invention relates to a defrost arrangement for refrigeration systems and in the preferred embodiment to reverse cycle, heat pump refrigeration systems. A secondary defrost circuit is provided including valves which permit refrigerant flow to by-pass the compressor and the expansion device only when compressor operation terminates and the system pressure differential is equalized. The refrigerant flow in the secondary circuits allows refrigerant to flow between the upper portions and lower portions of the indoor and outdoor heat exchangers. This free non-restrictive flow of refrigerant causes the relatively warm refrigerant in gaseous phase when present in the condenser to displace the relatively cold refrigerant in liquid phase when present in the evaporator, with the flow continuing until the system equalizes.

Abstract: A method and apparatus for controlling a multiple compressor heat pump system such that when the system is in the heating mode of operation the compressors are cycled individually depending upon the ambient temperature level and are individually co-ordinately operated in a defrost mode. The electrical control means disclosed provides for a second compressor being energized when the outdoor heat exchanger of a first compressor is being defrosted and the first and second contact means located within the individual defrost circuits for the first and second outdoor heat exchangers such that when the first outdoor heat exchanger is being defrosted the second outdoor heat exchanger may not commence a defrost cycle and when the second compressor is being operated in a defrost cycle a first compressor may not commence a defrost cycle.

Abstract: To defrost a selected evaporator, in a system including at least two evaporators, the system condenser is isolated from the compressor and the selected evaporator receives hot, compressed refrigerant vapor directly from the compressor. The liquid refrigerant formed in the defrosting evaporator flows to the other evaporators in the system to permit them to continue in the refrigeration mode. A pressure regulated control system is provided which causes excess liquid refrigerant in the defrosted evaporator to be pumped out of that evaporator before the evaporator is reconnected to the compressor suction line. In a preferred embodiment, each evaporator includes a coil having a plurality of circuits connected between its inlet and outlet and each circuit is disposed in a horizontal plane at a different elevation from any of the other circuits.

Abstract: A vehicle eutectic plate refrigeration system provides simultaneous defrosting of part of the plate exterior surface, all of the secondary heat transfer surface and freezing of the eutectic solution within the plate. This system thus preserves sufficient space for air passage, which otherwise would be blocked by frost and ice. The system utilizes the normally rejected heat to perform a defrosting function and utilizes the ice and frost to perform the refrigerant condensing function. Hot gas from the compressor is diverted through the defrost coil where the refrigerant is for the most part condensed before it is passed through the condenser. The liquid refrigerant from the condenser is then used to freeze the eutectic solution within the plate.

Abstract: The present invention relates to a compressor refrigeration plant comprising a throttling device between the condenser and evaporator and, associated with the throttling device, an intermittently operable electric heating resistor, a chamber being disposed upstream of at least a part of the throttling device and the electric heating resistor being a PTC resistor which is arranged in the chamber and which, when a temperature range between the evaporating temperature of the refrigerant associated with the pressure in the chamber and the coking temperature of the refrigerant oil is exceeded, goes over from a low to a high resistance.

Abstract: A refrigerator cabinet feed-through grommet formed of resilient material comprising an outer sleeve section having one end formed with a double flange for sealingly connecting the grommet to the cabinet liner. The grommet has an inner socket section for supporting a rigid tube, enclosing an insulated electrical heater conductor, located in the space between the cabinet outer shell and inner liner. The socket portion includes stop means for seating the tube free edge so as to obviate any contact by the electrical conductor with the end of the tube. The interconnection of the socket section with the outer sleeve section is provided by a frusto-conical shaped lead-in section being sufficiently yieldable to permit the inner socket section to move out of concentrically spaced relation with the outer sleeve section so as to compensate for some misalignment of the tube with respect to the grommet.

Abstract: The present invention relates to a self-contained air conditioning unit including a reversible refrigeration system and more particularly to a control system having a plurality of sensing means that are effective in maintaining operation of the unit in a heat pump mode when the ambient and the surface temperature of selected refrigeration components are above a preselected frosting temperature.

Abstract: A refrigeration apparatus having a refrigerant fluid accumulator providing a supercharge of hot refrigerant in the system for improved defrosting at desired intervals. During the normal refrigeration operation of the apparatus, the supercharge fluid is stored in the accumulator as hot refrigerant liquid with the remaining refrigerant fluid in the system defining a full charge quantity for normal proper operation of the refrigeration apparatus. The additional refrigerant fluid further provides accelerated cooling of the evaporator of the apparatus upon initiation of the refrigeration operation subsequent to a defrosting operation for further improved efficiency of operation of the refrigeration apparatus.

Abstract: A refrigerator cabinet having a one-piece plastic liner wherein the liner is divided by a vertically extending partition into side-by-side compartments with the front face of the partition defining a center vertical mullion provided with a condensation preventing condenser hot gas tube reverse mullion loop, integral with the hot gas tube outer loop installed into the cabinet shell peripheral flange, with the mullion loop extending upwardly from integral torsional portions adjacent the refrigerator shell bottom wall. During manufacture of the refrigerator the one-piece liner is installed by rotating the mullion loop approximately 90.degree. out of the plane of the cabinet shell front access opening by twisting the condenser tube about the torsional portions thereby clearing the access opening for insertion of the one-piece liner. After placing the liner into the cabinet shell the loop is returned to the plane of the front access opening for retention in the mullion.