Abstract: An air conditioner provided which has: a main refrigerant circuit including a compressor, a heat source side heat exchanger, a first expansion valve, and a utilization side heat exchanger and configured such that refrigerant flows in the main refrigerant circuit; a sub refrigerant circuit including a cooling member configured such that refrigerant branched from the main refrigerant circuit flows in the cooling member and configured such that refrigerant branched from the main refrigerant circuit flows in the sub refrigerant circuit; and a heat generator to be cooled by the cooling member, wherein a pipe in which part of refrigerant discharged from the compressor flows is connected to the cooling member of the sub refrigerant circuit.

Abstract: An air conditioner provided which has: a main refrigerant circuit including a compressor, a heat source side heat exchanger, a first expansion valve, and a utilization side heat exchanger and configured such that refrigerant flows in the main refrigerant circuit; a sub refrigerant circuit including a cooling member configured such that refrigerant branched from the main refrigerant circuit flows in the cooling member and configured such that refrigerant branched from the main refrigerant circuit flows in the sub refrigerant circuit; and a heat generator to be cooled by the cooling member, wherein a pipe in which part of refrigerant discharged from the compressor flows is connected to the cooling member of the sub refrigerant circuit.

Abstract: A gas supply system (2) includes a compressor unit (21), an accumulator unit (23), a pre-cooling system (24) and a housing (4). In the gas supply system (2), the compressor unit (21) is vertically arranged and the pre-cooling system (24) is arranged above the accumulator unit (23) in the housing (4). The compressor unit (21) and the accumulator unit (23) are covered by one rectangular parallelepiped housing (4).

Abstract: A transport refrigerant vapor compression system includes a controller for controlling operation of the transport refrigerant vapor compression system. The controller is configured to modulate a discharge pressure of the refrigerant compression device to control a cooling capacity of the transport refrigerant vapor compression system. The controller is configured to modulate the discharge pressure of a refrigerant compression device to control the cooling capacity of the transport refrigerant vapor compression system using both a refrigerant reservoir and an auxiliary expansion device without affecting superheat of the transport refrigerant vapor compression system.

Abstract: A thermosiphon cooling system is presented. One embodiment of the thermosiphon cooling system includes a reservoir having a first portion configured to store a liquid coolant. The thermosiphon cooling system also includes a tubing unit coupled to the reservoir and disposed adjacent to at least one superconducting unit to be cooled and configured to receive the liquid coolant from the first portion of the reservoir, and circulate the received liquid coolant within the tubing unit to dissipate heat generated by the at least one superconducting unit. The received liquid coolant is circulated within the tubing unit by varying a density of the received liquid coolant at different portions of the tubing unit.

Abstract: Systems and methods are provided for detecting low refrigerant charge in a refrigeration system. Specifically, the present invention provides systems and methods for comparing refrigerant charges of the refrigeration system during at least substantial shut down.

Abstract: Methods and systems to manage refrigerant levels in a chiller system are provided. An evaporator of the chiller system may be configured to have a spill over port allowing oil containing refrigerant to spill over through the spill over port. The spill over port may be positioned at a place that corresponds to a desired refrigerant level in the evaporator. The spill over refrigerant may be directed into a heat exchanger that is configured to substantially vaporize refrigerant of the spill over refrigerant to a slightly superheat temperature. A method of maintaining a proper refrigerant level in the evaporator may include regulating a refrigerant flow to the evaporator so that the vaporized refrigerant of the spill over refrigerant is maintained at the slightly superheat temperature.

Abstract: A refrigeration system 4 controlled by a control system 26, wherein the refrigeration system 4 comprises: an evaporator 8, a compressor 10, a condenser 12, and an expansion arrangement 15. The control system 26 is adapted: to establish a momentary cooling requirement based on the differential between a set-point temperature and an actual temperature averaged over time, to form a requirement variable relating to the momentary cooling requirement, to fix a first duration during which the compressor is switched on and a second duration during which the compressor is switched off, and to switch on and to switch off the compressor according to the first and second durations. The refrigeration system 4 comprises a first shut-off valve 20. The control system 4 is adapted: to close the first shut-off valve 20 in connection with switching off the compressor 10, and to open the first shut-off valve 20 in connection with switching on the compressor 10.

Abstract: In some embodiments, a portable cooling unit for use with a storage container includes: a desiccant unit including at least one exterior wall defining an interior desiccant region, wherein the interior desiccant region is sealed from gas transfer between the interior desiccant region and a region external to the cooling unit; an evaporative cooling unit including at least one exterior wall defining an interior evaporative region, wherein the interior evaporative region is sealed from gas transfer between the interior evaporative region and the region external to the cooling unit; a vapor conduit including a first and a second end, the vapor conduit attached to the desiccant unit at the first end, the vapor conduit attached to the evaporative cooling unit at the second end, the vapor conduit forming a passageway between the interior desiccant region and the interior evaporative region; and a vapor control unit attached to the vapor conduit.

Abstract: A refrigeration system includes a compressor; a condenser connected to a first inlet of a separator which has: a vapor outlet connected to the compressor and a liquid outlet connected to an evaporator; a selecting valve having: a first vapor inlet connected to the evaporator; a second vapor inlet connected to the separator; and a vapor outlet connected to the compressor, the selecting valve being operated to selectively and alternatively communicate its first and second vapor inlets with its vapor outlet, so as to allow the compressor to draw vapor from the separator and from the evaporator; and a control unit for controlling the operation of the selecting valve.

Abstract: The present invention relates to a refrigerator and a method for controlling a refrigerator, and more particularly to a refrigerator and a method for controlling a refrigerator in which unnecessary operation of a compressor is prevented for saving power consumption of the refrigerator. The refrigerator includes a compressor, a refrigerating chamber evaporator and a freezing chamber evaporator connected to the compressor, a refrigerant valve for guiding refrigerant to the refrigerating chamber evaporator or the freezing chamber evaporator, and a control unit for controlling the refrigerant valve such that the refrigerant valve blocks or introduces the refrigerant to cause an inside pressure of the freezing chamber evaporator to be elevated higher than an inside pressure of the refrigerating chamber evaporator during evaporation at the refrigerating chamber evaporator for the compressor to draw in the refrigerant remained in the freezing chamber evaporator which did not evaporate.

Abstract: A flow device for a refrigerant/compressor system is installed between the outlet of an evaporator and the suction port of a compressor. The device includes a floating element that helps inhibit liquid refrigerant from entering the compressor. Under certain conditions where liquid refrigerant discharges from the evaporator, the floating element floats in the discharged liquid. Upon doing so, the float rises to a generally closed position where the float obstructs a main fluid outlet that leads to the compressor. In the closed position, refrigerant can still pass through the flow device, but through a more restricted outlet. To prevent the float from undesirably rising under the impetus of refrigerant vapor flowing at high flow rates, the floating element itself includes a flow-restricting passageway, radial guides, and/or a streamlined shape. The float can be incorporated within a manifold of a multi-coil or multi-circuited heat exchanger.

Abstract: In a heat pump apparatus, switching between high efficiency operation, being efficient, and high capacity operation, having high capacity, is performed according to the state of the load. There are provided a main refrigerant circuit that uses an ejector, a first sub-refrigerant circuit that connects a portion between a heat exchanger and an ejector to a portion between a gas-liquid separator and a heat exchanger, and a second sub-refrigerant circuit that connects a portion between the heat exchanger and the ejector to an injection pipe of a compressor. When the load is about medium, refrigerant is circulated in the main refrigerant circuit to perform an efficient ejector aided operation utilizing the ejector. When the load is large, a high capacity injection operation is performed by flowing refrigerant to the second sub-refrigerant circuit. When the load is small, a simple bypass operation which prevents degradation of efficiency is performed by flowing refrigerant to the first sub-refrigerant circuit.

Abstract: The refrigeration system includes a compressor; a condenser connected to a first inlet of a separating means which has: a vapor outlet connected to the compressor and a liquid outlet connected to an evaporator; a selecting valve having: a first vapor inlet connected to the evaporator; a second vapor inlet connected to the separating means; and a vapor outlet connected to the compressor, said selecting valve being operated to selectively and alternatively communicate its first and second vapor inlets with its vapor outlet, so as to allow the compressor to draw vapor from the separating means and from the evaporator; and a control unit for controlling the operation of the selecting valve.

Abstract: A control algorithm for controlling an economizer circuit in a chiller system is provided. The control algorithm opens and closes a port valve in the economizer circuit in response to predetermined criteria to engage and disengage the economizer circuit. The predetermined criteria can include an operating parameter of a compressor and a level of liquid refrigerant in a flash tank.

Abstract: An evaporator (168) in a vapor compression system (14) (168) includes a shell (76), a first tube bundle (78); a hood (86); a distributor (80); a first supply line (142); a second supply line (144); a valve (122) positioned in the second supply line (144); and a sensor (150). The distributor (80) is positioned above the first tube bundle (78). The hood (88) covers the first tube bundle (78). The first supply line (142) is connected to the distributor (80) and an end of the second supply line (144) is positioned near the hood (88). The sensor (150) is configured and positioned to sense a level of liquid refrigerant (82) in the shell. The valve (122) regulates flow in the second supply line in response to the level of liquid refrigerant (82) from the sensor (150).

Abstract: A refrigerant floating expansion apparatus including a main body, a standpipe, a float element and a separation element is provided. The main body includes a base plate and a pipe-shaped housing. The standpipe fixed on the base plate has a second pipe opening and a third pipe opening. The pipe wall of the standpipe has at least an opening near the second pipe opening. The float element surrounds the standpipe for controlling a fluid-passing area of the opening. The separation element surrounding the float element is disposed on the base plate and forms an inner path with the pipe-shaped housing. The separation element has several fluid passageways near the base plate. A high-pressure fluid entering the main body is guided to pass through the fluid passageways to move the float element for controlling the fluid-passing area of the opening. Then, the high-pressure fluid is transferred to a low-pressure fluid.

Abstract: A level control algorithm for an HVAC refrigeration system is provided. The control algorithm utilizes a fuzzy logic methodology to automatically adjust a flow of refrigerant in the system to maintain a desired liquid level in the condenser. The fuzzy logic methodology incorporates a plurality of fuzzy logic control algorithms each having different membership functions and other control parameters that can provide different degrees of level control in the condenser. A particular fuzzy logic control algorithm is selected based on the amount a measured liquid level in the condenser deviates from the desired liquid level in the condenser.

Abstract: A level control algorithm for an HVAC refrigeration system is provided. The control algorithm utilizes a fuzzy logic methodology to automatically adjust a flow of refrigerant in the system to maintain a desired liquid level in the condenser. The fuzzy logic methodology incorporates a plurality of fuzzy logic control algorithms each having different membership functions and other control parameters that can provide different degrees of level control in the condenser. A particular fuzzy logic control algorithm is selected based on the amount a measured liquid level in the condenser deviates from the desired liquid level in the condenser.

Abstract: A refrigerant floating expansion apparatus including a main body, a standpipe, a float element and a separation element is provided. The main body includes a base plate and a pipe-shaped housing. The standpipe fixed on the base plate has a second pipe opening and a third pipe opening. The pipe wall of the standpipe has at least an opening near the second pipe opening. The float element surrounds the standpipe for controlling a fluid-passing area of the opening. The separation element surrounding the float element is disposed on the base plate and forms an inner path with the pipe-shaped housing. The separation element has several fluid passageways near the base plate. A high-pressure fluid entering the main body is guided to pass through the fluid passageways to move the float element for controlling the fluid-passing area of the opening. Then, the high-pressure fluid is transferred to a low-pressure fluid.

Abstract: An air conditioner that adjusts the temperature in a target space includes a refrigerant circuit and a controller. The refrigerant circuit is configured by the interconnection of a compressor, an outdoor heat exchanger, indoor expansion valves, and indoor heat exchangers. The controller adjusts the temperature such that predetermined temperature is reached in a target space. In addition, the controller judges the refrigerant quantity in the refrigerant circuit based on at least one value of operation state quantity of constituent equipment or refrigerant flowing in the refrigerant circuit. The controller achieves a state in which the target space temperature satisfies a predetermined temperature condition.

Abstract: A control algorithm for controlling an economizer circuit in a chiller system is provided. The control algorithm opens and closes a port valve in the economizer circuit in response to predetermined criteria to engage and disengage the economizer circuit. The predetermined criteria can include an operating parameter of a compressor and a level of liquid refrigerant in a flash tank.

Abstract: A batch freezing ice cream machine for cooling liquid ice cream into frozen ice cream includes a flooded evaporator or evaporator having an auxiliary tank or section of the evaporator that can ensure that a cooling chamber is surrounded by liquid refrigerant during normal operation. The mix from the evaporator is placed in a freezer for ripening once it reaches a particular consistency in the evaporator.

Abstract: A vapor compression system in which a quantity of a refrigerant circulates between at least two pressure levels in a condenser and an evaporator respectively, comprises a compressor (1) for increasing the pressure of refrigerant vapor; a condenser (5) for high pressure refrigerant vapor received from the compressor; an expansion device (13) such as a valve across which the pressure differential between the condenser and the evaporator is maintained, to control the withdrawal of liquid refrigerant from the condenser according to the volume of liquid refrigerant that is within or behind it; an evaporator (15) for liquid refrigerant received from the condenser; a receiver (21) into which refrigerant is discharged from the evaporator, with a vapor withdrawal conduit (25) through which vapor is withdrawn from the receiver for supply to the compressor, the receiver including a reservoir (23) into which liquid refrigerant discharged from the evaporator collects, to control supply of liquid refrigerant to the compres

Abstract: Chiller operating efficiency is optimized by controlling the system to maintain the condenser liquid refrigerant level at a value which will minimize or prevent gas bypass to the evaporator. This is accomplished by sensing the level of liquid refrigerant in the condensor and incorporating fuzzy logic to properly position a multi-position valve which can variably restrict the flow of this liquid into the evaporator, according to this sensed parameter. The fuzzy logic utilizes as inputs both the level error from a set point level and the rate of change of the sensed level. Each of these inputs are combined by fuzzy logic techniques to provide the required output signal to control the opening and closing of the valve.

Abstract: A fluid level sensor. The sensor comprises a housing; a chamber enclosed by the housing; a liquid port in a lower area of the housing operable to connect the chamber to a lower, liquid containing area of a heat exchanger; and a gas port located in an upper area of the housing and operable to connect the chamber to an upper, vapor containing area of a heat exchanger. The sensor includes first and second apertures in the housing; and cooling conduit passing through the chamber and through the first and second apertures and operable to cool the chamber. There is at least one sensor located in the chamber and adapted to sense a temperature of fluid in the chamber.

Abstract: A heat pump apparatus which includes: an accumulator and a sub-accumulator for additionally accommodating the refrigerant arranged between the accumulator and the compressor, in which at least the accumulator or the sub-accumulator is provided with a flow control valve for controlling the refrigerant flow upstream of the accumulator or the sub-accumulator in association with the liquid refrigerant level detected by the level sensor; a bypass line with a bypass valve for bypassing the expansion valve, for controlling the opening of the bypass; and, preferably, a level sensor for sensing the liquid refrigerant level therein; thereby inhibiting the occurrence of foaming of the refrigerant and preventing the refrigerant from entering the compressor, especially at the start-up of the compressor.

Abstract: A flash tank economizer containing a first expansion device to expand high pressure refrigerant from a system condenser to an intermediate pressure and a second expansion device for further expanding liquid refrigerant at the intermediate pressure that has collected in the tank to a desired low pressure for delivery to the system evaporator. Vapor phase refrigerant produced by the first expansion in the tank is injected back into the system compressor at the intermediate pressure.

Abstract: A heat pump apparatus includes a liquid refrigerant flow control valve connected in fluid communication between a condenser and evaporator. The liquid flow control valve includes a refrigerant outlet tube connected in fluid communication with an expansion orifice and extends in thermal contact with an upper portion of the valve housing for controlling condensing of vapor refrigerant within the housing to thereby stabilize refrigerant flow. A float, movably positioned within the housing, cooperates with the expansion orifice for controlling a flow of refrigerant passing from the housing to the evaporator based upon a level of liquid refrigerant within the housing. When a large amount of vapor refrigerant arrives at the liquid flow control valve as a result of a control oscillation or system disturbance, the float moves downwardly, thereby reducing flow through the expansion orifice, cooling the outlet tube and causing vapor to condense more quickly in the housing.

Abstract: A refrigeration system includes a phase separator disposed in flow communication with a pulse width modulated solenoid valve. A thermistor is disposed in the phase separator and is submerged in either refrigerant liquid or refrigerant vapor during operation, with the electrical resistance thereof correspondingly changing. In an exemplary embodiment, a second thermistor is used in conjunction with the first thermistor and is disposed in the vapor inside the phase separator to provide a reference. By comparing voltage developed across the two thermistors during operation it may be determined whether one or both of the thermistors are submersed in the vapor. The duty cycle of the valve may therefore be increased when one of the thermistors is submerged in the liquid, and decreased when both thermistors are submersed in the vapor.

Abstract: A condenser that is a block of tubes and ribs with lateral collecting tubes, is provided with a tube-shaped collector in parallel to one of these collecting tubes and forms a unit with it, at least one float being arranged in this tube-shaped collector. The at least one float carries a transmitter element to which a receiver element is assigned which is arranged on the outside on the collector and receives signals through a wall of the collector.

Abstract: A vapour compression system, in which the pressure and flow rate of refrigerant in components of the system to control and to optimise use of heat-transfer surfaces and to minimise power consumption, comprises a compressor 1, a condenser 5, a two-section evaporator 15, and a needle float valve 13 for maintaining a pressure differential between the condenser and the evaporator. The two section evaporator comprises a first section 17 which receives refrigerant from the condenser and which partially evaporates it to discharge two-phase refrigerant into a reservoir 23 in which liquid refrigerant is collected and from which low pressure refrigerant vapour is supplied to the compressor, and a second section 19 which receives liquid refrigerant from the reservoir and evaporates it at least partially.

Abstract: A single-fluid two-phase turbine expander is employed in a compression-expansion refrigeration system. The turbine has nozzles of fixed, predetermined orifice and is designed for optimal operation in steady-state normal conditions. A main float valve governs the refrigerant flow to the turbine expander. In order to accommodate off-design conditions, a bypass conduit carries liquid refrigerant around the turbine expander directly to the evaporator. In this case a bypass float valve opens the bypass conduit when the liquid level in the condenser sump reaches a predetermined high level. Alternatively, a float switch and a bypass solenoid can be employed.

Abstract: A refrigeration system comprises an evaporator overfed with liquid refrigerant and discharging a mixture of vapor refrigerant and liquid refrigerant; a compressor for compressing vapor refrigerant discharged from the evaporator; a condenser receiving compressed vapor refrigerant from the compressor for transforming it into liquid refrigerant; and a receiver receiving the liquid refrigerant from the condenser and supplying it to the evaporator. A separator receiving the refrigerant discharged from the evaporator separates the-vapor refrigerant for the compressor from the liquid refrigerant for recirculation. A feeder stores the pressurized liquid refrigerant and overfeeds the evaporator therewith. An educer feeds liquid refrigerant from the separator to the feeder using liquid refrigerant from the receiver as pressurizing agent.

Abstract: Pulse width modulation is used to control the flow rate through a solenoid expansion valve in a refrigeration system using a simple vapor compression cycle. The refrigeration cycle includes a phase separator which receives two phase refrigerant from the condenser and supplies liquid refrigerant to the pulse width modulated solenoid valve. A liquid level sensor is disposed in the phase separator, and a controller for controlling the duty cycle of the pulse width modulated solenoid valve is provided to receive input from the liquid level sensor. The liquid level sensor can be of the type which provides a continuously variable signal as a function of liquid level, or it can be a liquid level switch which controls valve duty cycle on the basis of whether the phase separator liquid level is above or below a set level. Alternatively, two liquid level switches can be provided.

Abstract: A refrigerant flow control system for regulating the flow of a refrigerant liquid from a condenser sump to an evaporator wherein the control system regulates the liquid flow as a function of both the level of the liquid in the condenser sump and the system pressure differential between the condenser and evaporator of the refrigeration system. The flow control system includes a stop, biasing means, a guidepost, a standpipe, a generally tubular metering sleeve, and a float member.

Abstract: A dehumidifying machine is used for dehydrating materials and includes a tank used for depositing the materials therein, a draft tube system which has an inlet portion and an outlet portion communicated with the tank, an induced draft fan which is mounted in the draft tube system between the inlet and outlet portions and which has an inhaling portion and an exhaling portion so as to circulate the air in the dehumidifying machine, and a heating device mounted in the draft tube system in order to heat the air, which is exhaled from the outlet portion of the draft tube system into the tank so as to dehydrate the materials. The dehumidifying machine further includes a filter device which is mounted in the draft tube system near the inlet portion so as to block impurities carried in the air from moving into the heat device and the tank.

Abstract: A vapour compression system, in which the pressure and flow rate of refrigerant in components of the system to control and to optimize use of heat-transfer surfaces and to minimize power consumption, comprises a compressor 1, a condenser 5, a two-section evaporator 15, and a needle float valve 13 for maintaining a pressure differential between the condenser and the evaporator. The two section evaporator comprises a first section 17 which receives refrigerant from the condenser and which partially evaporates it to discharge two-phase refrigerant into a reservoir 23 in which liquid refrigerant is collected and from which low pressure refrigerant vapour is supplied to the compressor, and a second section 19 which receives liquid refrigerant from the reservoir and evaporates it at least partially.

Abstract: A float-type refrigerant control device meters the flow of saturated refrigerant liquid condensate to a subsequent stage from an outlet of a sump in a refrigerant condenser. A float in the form of a metal shell open at the bottom is slidably positioned on an upright, generally cylindrical standpipe which is mounted at the outlet of the sump. A metering sleeve situated within the standpipe is joined to the float for axial travel with the float. One or more metering slots penetrate the standpipe near its lower end, and these are uncovered by the sleeve as the float rises to permit the liquid to flow out through the sump outlet. A vapor injection duct supplies refrigerant vapor from a high pressure source to the float to keep the same replenished with vapor, thereby maintaining a positive buoyancy relative to the saturated refrigerant liquid condensate in the sump.

Abstract: A refrigerant recovery system includes a compressor and an evaporator connected to the compressor inlet for evaporating refrigerant passing therethrough to the compressor inlet from refrigerant equipment under service. A sensor is coupled to the system input for detecting presence of liquid phase refrigerant. A valve is connected to the compressor inlet in parallel with the evaporator for bypassing refrigerant from the evaporator to the compressor inlet when the sensor indicates that liquid refrigerant is absent at the system input. The liquid refrigerant sensor takes the form of an open canister between the system input and the evaporator, and a liquid level sensor coupled to the canister for sensing level of liquid refrigerant collected within the canister. A solenoid valve is connected in parallel with the evaporator, and is responsive to the liquid level sensor for opening the valve and bypassing the evaporator in the absence of liquid refrigerant within the canister.

Abstract: A heat-pump type cooling system is disclosed which can provide cooling immediately before the compressor begins to rotate. The system stores liquid refrigerant condensed from compressed high pressure vapor in a liquid container, and releases it, through a control valve, to an evaporator and a temporary vapor receiver, enabling the cooling power to be controlled independently of the rotation of the compressor, in accordance with the operation of the control valve and the evaporator.

Abstract: A simple flow control device is provided in a condensate drain pipe to prevent the flow of refrigerant vapor therethrough and to regulate the flow of liquid refrigerant as a function of the level of accumulated liquid refrigerant in the drain pipe. The only moving part is a float device that rides up on a cylindrical valve body in response to the level of liquid refrigerant to thereby expose slots in the valve body which allow for the flow of liquid refrigerant to the refrigerant return line to the cooler.

Abstract: An air conditioning system for buildings includes a plurality of air conditioners on the different floors, a cooling gravity type heat pipe connecting vaporizers in the air conditioners with a cold thermal source installed at the top of the building and a warming gravity type heat pipe connecting a condenser of the air conditioners with a hot thermal source installed in the basement of the building. The heat pipes are, respectively, provided with flow control valves at the inlet of each vaporizer and the outlet of each condenser. Each air conditioner is provided with a thermistor for detecting the temperature of the returning air and a liquid level detection switch for detecting the liquid level of the thermal medium in the vaporizer. The flow control valves are respectively controlled based on the detection signals issued by the thermistor and the liquid level detection switch.

Abstract: An air-to-air heat pump with improved efficiency of operation, and simplicity and economy of construction. Initiation and termination of defrost cycles during heating mode operation is controlled, in addition to the conventional clock timer, by a dual pressure switch responsive to pressure in the outdoor coil, thereby significantly reducing the length of defrost cycles with corresponding improvement in operating efficiency. The direction of refrigerant flow between the indoor and outdoor coils is established in a first line through the compressor by an electrically operated reversing valve, and alternatively through second and third lines, depending upon whether the system is operating in the heating or cooling mode, by series-connected check and float valves in each of such lines. When heating mode operation is resumed following a defrost cycle, the float valve has delivered all liquid-refrigerant to the indoor coil.

Abstract: A liquid/gas bypass line bypasses an expansion device of a refrigeration apparatus. An inlet of the bypass line is connected slightly above the bottom of a condenser so that it can pass either liquid refrigerant or vaporous refrigerant, depending on the level of liquid refrigerant in the condenser. The other end of the bypass line is connected to discharge into the evaporator, bypassing the expansion device. The bypass line functions as a conventional hot gas bypass during low load conditions when the level of liquid refrigerant is below the line's inlet. When the level rises above the inlet, often occurring when the condenser coolant temperature is low and the compressor is fully loaded, the bypass line returns excess accumulated liquid refrigerant to the evaporator. Maintaining the proper levels of liquid refrigerant in both the condenser and the evaporator not only provides the most effective use of their heat transfer surfaces, but also promotes the proper return of oil to the compressor.

Abstract: Method and Apparatus for cooling a mold having plural parallel cooling passages therethrough, the mold having flow control means at the inlet and sight glasses at the outlets and being arranged for overfeed so that liquid is always present in all cooling passages to avoid hot spots in the mold.

Abstract: The present invention relates to a refrigeration system of the type having an air cooled condenser which includes the further capability of producing a heated liquid in a liquid cooled or, "heat recovery" condenser. The system includes compressor means for compressing a vaporized refrigerant, air cooled condenser means having fan means for forcing air in heat exchange relationship therewith, liquid cooled condenser means for producing a heated liquid, and evaporator means for expanding and vaporizing condensed refrigerant in heat exchange relationship with a refrigeration load. Control means are provided for the system and include first means for sensing the demand for heated liquid from the liquid cooled condenser, and second means responsive to the first means for reducing the capacity of the fan means in response to increased demand for heated liquid.

Abstract: A heat exchanger fabricated from a plurality of plates arranged in spaced parallel relation with one another and assembled as a stack between pressure plates. The assembled stack of plates have top, bottom, and side cover members with one of the side covers having a liquid inlet and a vapor outlet. The liquid inlet is provided with a float control nozzle mechanism, that under certain conditions, will restrict or limit the flow of liquid to the plate members.