Abstract: A valve assembly for an air conditioning system includes a liquid line port pressurized at a discharge pressure, an evaporator inlet port pressurized at a suction pressure, a sequence valve for controlling a first flow path between the liquid line port and an outlet in response to a differential between the discharge pressure and the suction pressure, and a thermostatic expansion valve that includes an actuator and an expansion valve member for controlling a second flow path between the outlet and the evaporator inlet port in response to a pressure differential across the actuator.

Abstract: A refrigerant expansion assembly, and method of operation, for use in a vehicle air conditioning system is disclosed. An orifice channel connects an orifice inlet port to an orifice outlet port and includes a valve seat. A variable orifice assembly is mounted in the orifice channel and includes a fixed orifice passage extending axially through a variable orifice body having a sealing flange that can seal against a valve seat via an orifice spring. An orifice bypass valve includes a check ball biased against a ball seat by a bypass spring and selectively allows some of the refrigerant to bypass the variable orifice assembly. The refrigerant expansion assembly may also include a burst disk downstream of the variable orifice assembly.

Abstract: A refrigerant expansion assembly, and method of operation, for use in a vehicle air conditioning system is disclosed. The assembly has a main body including an orifice inlet port, an orifice outlet port, an orifice channel extending between the orifice inlet and outlet ports and including a fixed orifice, an upstream bypass channel extending from the orifice channel between the orifice inlet port and the fixed orifice and including a valve seat, and a downstream bypass channel extending from the orifice channel between the fixed orifice and the orifice outlet port. A bypass valve flange extends from the main body, forming a bypass chamber connected to the upstream bypass channel and the downstream bypass channel, with the ball valve seat adjacent to the bypass chamber. A check ball mounts in the bypass chamber adjacent to the valve seat, and a spring biases the check ball into the valve seat.

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: In a refrigerant circuit (20), an air conditioning unit (12), a cold-storage showcase (13), and a freeze-storage showcase (14) are connected in parallel to an outdoor unit (11). When placing an indoor heat exchanger (71) of the air conditioning unit (12) in the thermo-off state, a degree-of-opening control means (101) provides control so that an indoor expansion valve (72) is placed in the fully closed state. Thereafter, the degree-of-opening control means (101) detects the accumulated amount of refrigerant within the indoor heat exchanger (71) and then adjusts the degree of opening of the indoor expansion valve (72) depending on the refrigerant amount detected.

Abstract: Provided is an air conditioner, particularly, an apparatus and method for controlling a super-heating degree in a heat pump system for preventing a liquid refrigerant from flowing into a compressor. The method includes: operating the heat pump system; receiving a present outdoor temperature, a pipe absorption temperature and a low pressure value of a compressor, respectively; computing a present absorption super-heating degree from a difference between the absorption temperature of the compressor and a saturated temperature at a low pressure side; and comparing an targeted absorption super-heating degree set in advance, with the computed present absorption super-heating degree according to the received outdoor temperature, and controlling the system so that the present absorption super-heating degree may follow the targeted absorption super-heating degree.

Abstract: A pressure control valve includes a valve portion disposed in a passage from a refrigerant radiator to a suction port of a refrigerant compressor in a vapor-compression refrigerant cycle system. The valve portion controls a refrigerant pressure at an outlet of the refrigerant radiator in accordance with a refrigerant temperature at the outlet of the refrigerant radiator, and the valve portion has a control pressure characteristic in which a pressure change relative to a temperature is smaller than that of the refrigerant. Furthermore, the valve portion may have a fluid passage through which refrigerant flows even when a valve port of the valve portion is closed by a valve body. Accordingly, when the refrigerant radiator is used for heating a fluid, heating capacity for heating the fluid can be rapidly increased at a heating start time.

Abstract: A refrigerator has a discharge three-way valve (8) for connecting the discharge side of a compressor (1) to at least either a hot water heat exchanger (3) or an air heat exchanger (6) and has a suction three-way valve (9) for connecting the suction side of the compressor (1) to at least either the air heat exchanger (6) or a cold water heat exchanger (4). In an operation primarily for cooling, a controller (19) regulates the opening of the discharge three-way valve (8) such that a refrigerant with a flow rate higher than a minimum flow rate (Qs) determined based on an outside air temperature flows to the air heat exchanger (6).

Abstract: The invention concerns a refrigeration system comprising a refrigerant circuit which comprises several evaporator paths and a distributor (5) which distributes the refrigerant on the evaporator paths. The aim of the invention is to improve the operation of said refrigeration system in a simple manner. According to the invention, the distributor (5) comprises a controllable valve (12) for each evaporation path.

Abstract: The present invention discloses an air conditioning system comprises a phase separator separating a gaseous refrigerant and a liquid refrigerant from a flowing refrigerant, an evaporator evaporating the liquid refrigerant separated by the phase separator, and at least one compressor including a first compressing part receiving the refrigerant via the evaporator and a second compressing part receiving both of the gaseous refrigerant separated by the phase separator and the refrigerant via the first compressing part, wherein a volume of a first cylinder of the first compressing part is different from a volume of a second cylinder of the second compressing part.

Abstract: The present invention relates to a flow rate control system in refrigeration circuits, to a method for controlling a refrigeration system and to a refrigeration system properly speaking, which may include, for example, from a domestic refrigerator to an air conditioning system. In particular, the present invention is directed to a solution for the loss of efficiency in the expansion valve (17), when the system load varies, making the expansion valve (17) operate below its nominal capacity and, therefore, at low efficiency. One of the ways to achieve the objectives of the present invention is through a flow rate control system in refrigeration circuits comprising a hermetic compressor fluidly connected to a closed circuit (20).

Abstract: A machine for producing liquid and semi-liquid consumer food products comprises one or more containers (2) for a basic product of the consumer product to be made; a refrigeration system (3) acting on the containers (2) to reduce the temperature of the basic product; the refrigeration system (3) comprising a predetermined refrigerant; the refrigerant being carbon dioxide and the refrigeration system (3) being set up to carry out a transcritical refrigeration cycle on the refrigerant.

Abstract: An air conditioning system can improve the cooling/heating performance of the system because the injection of refrigerant into the compressor is achieved. The air conditioning system can further improve the cooling/heating performance in a low temperature region by injecting refrigerant as a two-phase refrigerant or a superheated vapor state into the compressor. The air conditioning system can prevent damage of the compressor and further improve reliability by controlling such that the ratio of a liquid refrigerant in the refrigerant injected into the compressor may be less than a set value.

Abstract: An expansion valve of the present invention has a structure which integrates a refrigerant flow divider. The expansion valve includes a refrigerant flow dividing chamber 6 on the downstream side of a first throttle 10. Flow dividing tubes 12 are connected to the refrigerant flow dividing chamber 6. In the expansion valve, refrigerant which has passed through the first throttle 10 is sprayed into the refrigerant flow dividing chamber 6, so that the flow dividing characteristic of the refrigerant is improved. Also, due to an enlargement of the passage in the refrigerant flow dividing chamber 6, the ejection energy of a flow of the refrigerant ejected from the first throttle 10 is dispersed, whereby a discontinuous refrigerant flow noise is reduced.

Abstract: An auger type ice making machine is provided with a freezing cylinder into which water for making ice is supplied, an ice-scraping auger for scraping ice formed on the inner surface of the freezing cylinder, and an auger motor for driving the ice-scraping auger. A freezing apparatus has a compressor driven by a motor, circulating refrigerant discharged from the compressor through a condenser, a dryer, a constant pressure expansion valve, and an evaporator provided on the outer peripheral surface of the freezing cylinder. At the outlet of the evaporator there is provided a temperature sensor for sensing refrigerant temperature. A controller controls the rotational speed of the motor through an inverter circuit such that the sensed refrigerant temperature is equal to a specified refrigerant temperature, allowing the freezing apparatus to keep ice-making performance thereof.

Abstract: A supercritical heat pump cycle system includes a low-pressure determining unit for determining a pressure of a low-pressure refrigerant after being decompressed in a decompression unit, a target temperature setting unit for setting a target temperature of the fluid, and a target pressure determining unit for determining a heating target control pressure in a refrigerant radiator based on the pressure of the low-pressure refrigerant and the target temperature of the fluid during the heating operation. In the supercritical heat pump cycle system, the decompression unit is controlled so that a refrigerant pressure in the refrigerant radiator becomes the heating target control pressure. Accordingly, heating capacity of the refrigerant radiator can be effectively increased.

Abstract: In an air conditioning system, a first expansion device and a second expansion device playing a different role from each other are controlled in a different control method suitable for each role, thereby improving the performance and stability of the system. Furthermore, the control method for the first expansion device is differentiated according to the operation state of the air conditioning system, thereby improving the stability of the system. Furthermore, the intermediate pressure can be adjusted more rapidly and precisely according to the state of the air conditioning system by differentiating the control method for the first expansion device for adjusting the intermediate pressure depending on the degree of superheat of the refrigerant, thereby improving the stability and performance of the system.

Abstract: A chiller includes a main condenser that has a refrigerant condensate sump with an internal weir or standpipe that maintains at least a minimum liquid seal between the outlets of the main condenser and a heat-recovery condenser. The main condenser is used for normal cooling operation, and the heat-recovery condenser is for supplying an external process with heat that would otherwise be wasted. In addition to providing a liquid seal, the sump and weir combination provides a reliable source of liquid refrigerant to cool the chiller's compressor motor and creates a trap for collecting foreign particles that might exit either of the chiller's two condensers.

Abstract: A refrigerant compressor having a compression element comprising sliding components made of metallic materials, wherein a mixed layer is formed by solid-dissolving molybdenum disulfide in at least one of the sliding faces of the sliding components, and a single molybdenum disulfide layer is further formed on the surface of the mixed layer. With this configuration, initial break-in is done using the single layer, and sliding loss is reduced. Even if the single layer peels off, because the molybdenum disulfide of the mixed layer is cleaved at a low friction coefficient, solid lubrication action is attained, the friction coefficient of the sliding section is lowered, and sliding loss is reduced.

Abstract: A high pressure control valve is arranged in a refrigerant passage formed from an internal heat exchanger to an evaporator 4 in a refrigerating cycle of CO2 refrigerant having the internal heat exchanger 8. The high pressure control valve 3, 3A to 3F controls refrigerant pressure on the internal heat exchanger outlet side according to a temperature of the refrigerant at the outlet of the radiator. Into a temperature sensing section (airtightly closed space A), the inner pressure of which is changed according to the refrigerant temperature on the radiator outlet side, CO2 refrigerant, the charging density of which is 200 to 600 kg/m3, preferably 200 to 450 kg/m3, is charged.

Abstract: A compressor discharges a flow of compressed fluid at a predetermined temperature. The compressor includes a sensor positioned to measure a first temperature indicative of the temperature of the compressed fluid, a coolant source, a cooler positioned to receive a first flow of coolant from the coolant source and discharge a flow of cooled coolant, and a valve positioned to receive the flow of cooled coolant and a second flow of coolant from the coolant source. The valve is configured to discharge a coolant flow to the compressor and the coolant flow has a ratio of cooled coolant to second flow of coolant that is variable in response to the first temperature.

Abstract: The present invention provides a vehicle air-conditioning system in which an air for air-conditioning is cooled at a first evaporator, is heated at a condenser, and is supplied to a vehicle interior in heating operation. The object of the present invention is to suppress a dew condensation at the first evaporator to prevent a freeze of the dew condensation water even if the temperature of the air for air-conditioning introduced from the outside of the vehicle is low. The above object is achieved by disposing a second evaporator between an automated expansion valve to decompress the refrigerant exhausted from a compressor and the first evaporator so as to reduce the absorbed heat at the first evaporator.

Abstract: A thermal sensing bulb for an expansion valve, the bulb containing a ballast material, the ballast material including a plurality of particles including a calcium silicate hydrate.

Abstract: Disclosed herein is a method of controlling a linear expansion valve of a cooling cycle apparatus. The method comprises a first step of calculating a target opening level value according to suction overheat level of compressors to control a linear expansion valve based on the calculated target opening level value, and a second step of calculating a new target opening level value according to the suction overheat level of the compressors and discharge temperature of the compressors to control the linear expansion valve based on the calculated new target opening level value. Consequently, the discharge temperature of the compressors is prevented from being excessively increased, and therefore, the compressors are prevented from being overheated and damaged, and reliability of the cooling cycle apparatus is improved.

Abstract: A refrigeration-cycle component assembly includes a pipe connecting member, a box temperature-sensitive expansion valve, an ejector, a passenger-compartment high-pressure pipe, and a passenger-compartment low-pressure pipe. The component assembly is provided in a flat space, which is defined at a side of an air-conditioning unit in a vehicle transverse direction, and which is flat in the vehicle transverse direction. The pipe connecting member and the refrigerant suction portion are intensively arranged at a vehicle front side in the flat space. The component assembly is entirely covered by a heat insulating member.

Abstract: A refrigerant unit associated with a product transport container is provided with a dual-path, parallel flow expansion circuit. The expansion circuit includes a primary expansion device disposed in a primary refrigerant flow path and an auxiliary expansion device disposed in a secondary refrigerant flow path. During operation of the refrigeration unit in a stable temperature maintenance mode, refrigerant flow is supplied to the evaporator coil through the primary refrigerant flow path only. During operation of the refrigeration unit in a temperature pull-down mode, to increase the refrigerant mass flow through the evaporator coil, refrigeration flow is supplied to the evaporator coil through the primary refrigerant flow path and the secondary refrigerant flow path of the expansion circuit.

Abstract: A system for atomizing the refrigerant directed to an evaporator in a vapor compression refrigeration system using spray nozzles. In one embodiment, one or more spray nozzles discharge into a distributor which is connected via a plurality of conduits to the various evaporator circuits. The distributor is designed to deliver a volume of refrigerant to each circuit based on airflow rates across the circuit. In another embodiment, an atomizing spray nozzle is interposed in each evaporator circuit and the nozzles are sized to distribute atomized refrigerant to the various evaporator circuits based on airflow rates. The invention also comprehends a method if improving the efficiency of existing system by replacing conventional expansion devices with spray nozzles sized in each circuit in relation to the airflow.

Abstract: The invention relates to an expansion valve and to a method for controlling an expansion valve, in which the opening and closing movement of the valve-closure member is set as a function of the pressure difference which is present in a feed opening on the high pressure side and in a discharge opening.

Abstract: A refrigerating machine includes a compressor for compressing a refrigerant, a radiator for radiating heat from the refrigerant discharged from the compressor, an expander for expanding the refrigerant discharged from the radiator, and an evaporators for evaporating the refrigerant discharged from the expanders, all connected in series. The refrigerating machine also includes a refrigerant flow regulator for regulating the amount of refrigerant flowing into the expander and a controller for controlling the compressor and the refrigerant flow regulator. At a stop of the compressor, the controller controls the refrigerant flow regulator to reduce the amount of refrigerant flowing into the expander.

Abstract: An air conditioner has an air conditioner casing in which air flows, an evaporator arranged in the air conditioner casing to cool air, an evaporator-side connector which protrudes from the evaporator toward an outer side of the air conditioner casing through an opening thereof, a piping-side connector, and a heat-insulating seal member. The piping-side connector and a refrigerant decompression member are respectively arranged at two ends of a piping group. A surrounding wall member surrounding the evaporator-side connector is erected at the air conditioner casing, so that a surrounding-shaped tip portion thereof projects beyond an end surface of a protrusion side of the evaporator-side connector. The heat-insulating seal member covers a whole area between the surrounding wall member and outer peripheral surfaces of the piping group.

Abstract: A refrigerant circuit R includes, a compressor 25 for compressing a refrigerant to a pressure higher than the critical pressure, a gas cooler 26, a motor-operated expansion valve 27, and an evaporator 28, and uses as a refrigerant a natural system refrigerant. A receiver 43 is provided to the high-pressure side of the refrigerant circuit R. There is provided an adjusting valve 44 for adjusting the refrigerant amount flowing through the inside of the receiver 43. A controller 55 adjusts the opening of the adjusting valve 44 so as to bring the temperature of the receiver 43 close to a target receiver temperature.

Abstract: An expansion valve capable of reducing noise due to acoustic resonance by allowing for adjustment of resonance characteristics of piping connected to a restricting portion and filled with a substantially liquid refrigerant, and an air conditioner using the same are provided. The expansion valve has a valve body 1, a restricting portion 18 formed inside the valve body 1, two piping connection portions 11, 12 communicating with the upstream side and the downstream side of the restricting portion 18, and at least one opening 30 that opens a refrigerant flow passage to outside of the valve body 1, the refrigerant flow passage extending from the piping connection portion 12 to which a piping 19 filled with a substantially liquid refrigerant is connected to the restricting portion 18.

Abstract: A refrigeration apparatus (1) is provided with a refrigerant circuit (1E) along which are connected a compressor (2), an outdoor heat exchanger (4), an expansion mechanism, an indoor heat exchanger (41) for providing room air conditioning, and a cooling heat exchanger (45, 51) for providing storage compartment cooling. The refrigerant circuit (1E) includes a discharge side three way switch valve (101) for varying the flow rate of a portion of the refrigerant which is discharged out of the compressor (2) and then distributed to the indoor heat exchanger (41) and the outdoor heat exchanger (4) during a heat recovery operation mode in which the indoor heat exchanger (41) and the outdoor heat exchanger (4) operate as condensers. As a result of such arrangement, even when the amount of heat obtained in the cooling heat exchanger (45, 51) exceeds the amount of heat required in the indoor heat exchanger (41), surplus heat is discharged without excessive decrease in the discharge pressure of the compressor (2).

Abstract: An air conditioning and heating system includes an condenser, an expansion valve, an evaporator and a compressor interconnected in a closed loop system, and a motor for driving the compressor. The system also includes a refrigerant disposed within the closed loop system. The compressor compresses the refrigerant and pumps the refrigerant through the system. The system also includes one or more feedback loops to reduce the temperature (pre-cool) the refrigerant before it reaches the expansion valve in the cooling mode and the same or a different heat exchanger in the heating mode. The additional heat exchangers are placed in the loop to reduce the electric energy being used.

Abstract: A refrigerant system comprising a compressor, a condenser, an electronic expansion valve, and an evaporator is controlled in a normal operating mode to meet moderate cooling loads; however, when the load approaches that which is sufficient to induce liquid refrigerant carryover from the evaporator to the compressor, the system is controlled in a capped operating mode to limit a certain thermodynamic variable rather than controlled to meet the high load. In the normal mode, the compressor and/or the expansion valve might be controlled in response to the amount of superheat of the refrigerant leaving the evaporator or the level of liquid refrigerant in the evaporator. In the capped operating mode, the compressor and/or the expansion valve might be controlled to limit a variable such as the compressor's capacity, the saturated pressure or dynamic pressure of the refrigerant entering the compressor, or the refrigerant's mass flow rate.

Abstract: On a single-stage type refrigerating system using non-azeotropic refrigerant, composing with a compressor (1), a condenser (2), and an evaporator (10), heat exchanging between returned-refrigerant from evaporator and high-pressure refrigerant toward evaporator, electromagnetic valves (5-1 to 5-4) of capillary tubes (6-1 to 6-4) as expansion valves of evaporator are fully open, at moments of large load needed such as at starting up, the system is controlled flux of refrigerant gas and pressure of it by closing them one by the other corresponding to going down of interior room temperature. As the state of interior room temperature is high and low boiling point constituent is not condensed, cooling capability of high boiling point refrigerant performs in maximum.

Abstract: An air conditioning system comprises a compressor 2 which compresses a refrigerant made of carbon dioxide, a radiator 4 which radiates heat of the refrigerant compressed by the compressor 2, an expansion valve 5 which decompresses the refrigerant which dissipated heat by the radiator 4 and which can control a refrigerant pressure on the outlet side of the radiator 4, an evaporator 7 which evaporates the refrigerant decompressed by the expansion valve 5, a sensor 13 which detects temperatures of a surface of a pipe through which a high pressure refrigerant on the outlet side of the radiator passes, and a control apparatus 23 which calculates a target refrigerant pressure on the outlet side of the radiator 4 based on a value detected by the sensor to control the expansion valve 5. The control apparatus corrects the target refrigerant pressure on the outlet side of the radiator 4 corresponding to refrigerant temperatures.

Abstract: The present invention concerns a method for improving the efficiency of a transcritical cooling installation and the installation itself.

Abstract: The invention relates to a refrigeration circuit having a mono- or multi-component refrigerant circulating therein, said refrigeration circuit comprising at least one expansion device. According to the invention, the expansion device is provided in the form of at least two valves (a, b, c, d) connected in parallel. Furthermore, the invention relates to a method of operating such a refrigeration circuit. Said method is characterized in that, in case of a defect of one of the valves (a, b, c, d) connected in parallel, said defective valve is taken out of operation and the or at least one of the additional valves ensures the control operation of the refrigeration circuit.

Abstract: The invention relates to a refrigeration machine, particularly a heat pump, comprising a closed circuit, which contains a coolant and in which an evaporator, a compressor, a condenser and an, in particular, electrically operated expansion valve are arranged one after the other. The refrigeration machine also comprises an overheating control unit for at least intermittently regulating the temperature of the coolant in the area of the compressor, particularly the compression final temperature. The invention also relates to a method for operating a refrigeration machine of the aforementioned type.

Abstract: A first motor-actuated expansion valve and a second motor-actuated expansion valve which are connected in parallel with each other in back-to-back connection are provided between an outdoor heat exchanger and an indoor heat exchanger. In the first motor-actuated expansion valve, at the time of non-operation and full closure, when the refrigerant pressure on the indoor heat exchanger side is higher than the refrigerant pressure on the outdoor heat exchanger side by a predetermined value or more, the full closure is released by receiving the refrigerant pressure on the indoor heat exchanger side. In the second motor-actuated expansion valve, at the time of non-operation and full closure, when the refrigerant pressure on the outdoor heat exchanger side is higher than the refrigerant pressure on the indoor heat exchanger side by a predetermined value or more, the full closure is released by receiving the refrigerant pressure on the outdoor heat exchanger side.

Abstract: There is disclosed a pressure control valve comprising: a valve body (10A) provided successively with, mentioning from the upstream side in the flowing direction of refrigerant, a refrigerant inflow port (11), a refrigerant introduction chamber (14), a valve seat (13) with which a rod-like valve (15) is retractably contacted, and a refrigerant outflow port (12); and a temperature-sensitive/pressure-responsive element (20) which is provided with a temperature sensitive chamber (25) for sensing the temperature of the refrigerant that has been introduced into the refrigerant introduction chamber (14) and is designed to drive the valve (15) in opening or closing direction in response to fluctuations of the inner pressure of the temperature sensitive chamber (25). The temperature-sensitive/pressure-responsive element (20) is integrally attached to the valve body (10A).

Abstract: A pulse width modulation control is provided for a suction valve on a suction line, delivering refrigerant into a housing shell of a compressor. When the suction valve is closed, the pressure within the housing shell can become very low. Thus, a pressure regulator valve is included within the refrigerant system to selectively deliver a limited amount of refrigerant into the housing shell when the suction valve is closed. The delivery of this limited amount of refrigerant ensures that a specified pressure is maintained within the housing shell to achieve the most efficient operation while at the same time preventing problems associated with damage to electrical terminals, motor overheating and excessive discharge temperature.

Abstract: A pressure control valve of a supercritical refrigeration cycle small in size and resistant to the effects of the outside air temperature, that is, a pressure control valve of a vapor compression type supercritical refrigeration cycle wherein a refrigerant is sealed in a sealed space at the top of the diaphragm, pressure of the refrigerant in the refrigeration cycle acts on the valve connected to the diaphragm, the valve opens and closes in accordance with the balance between the refrigerant pressure in the sealed space and the refrigerant in the refrigeration cycle, the sealed space is communicated with locations substantially having temperature sensing functions detecting the refrigerant temperature, and the volume of the locations substantially having the temperature sensing functions is at least 50% of the total volume of communicated with the sealed space.

Abstract: A compression system for an air conditioning system includes first and second compressors. The first compressor includes a first compression chamber in which a fluid introduced from an outside of the first compressor is compressed, and a first case defining a first space into which the fluid compressed in the first compression chamber is introduced. The second compressor includes a second case defining a second space into which the fluid compressed in the first compressor is introduced, and a second compression chamber in which the fluid introduced from the second space is compressed. The second compressor operates independently of the first compressor, and a connecting line connects the first and second compressors.

Abstract: A system and method for controlling the temperature of a process tool uses the vaporizable characteristic of a refrigerant that is provided in direct heat exchange relation with the process tool. Pressurized refrigerant is provided as both condensed liquid and in gaseous state. The condensed liquid is expanded to a vaporous mix, and the gaseous refrigerant is added to reach a target temperature determined by its pressure. Temperature corrections can thus be made very rapidly by gas pressure adjustments. The process tool and the operating parameters will usually require that the returning refrigerant be conditioned and processed for compatibility with the compressor and other units, so that cycling can be continuous regardless of thermal demands and changes.

Abstract: A variable capacity refrigeration system for a frozen product dispenser is controllable in response to cooling load requirements of the dispenser to have a variable cooling capacity that is in accordance with the cooling load demands placed on the refrigeration system by the dispenser. This is accomplished, in part, by providing the refrigeration system with a variable capacity compressor, the output capacity of which is controlled by varying its operating speed in a manner such that refrigerant output from the compressor generally meets the mass flow of refrigerant through expansion valves of the system. The arrangement provides for efficient operation of the frozen product dispenser from an energy standpoint and for a reduction in on/off cycling of the refrigeration system.

Abstract: A control system for a cooling system includes a first sensor for sensing a property indicative of demand for cooling and a controller coupled to the sensor. The controller produces the variable duty cycle control signal in response to the property and causes the compressor and valve to vary a cooling capacity of the cooling system in response to the variable duty cycle control signal. The sensor may sense the pressure, temperature, or both. The valve may be a suction-side pressure regulator or a liquid-side expansion valve of the solenoid or stepper type.

Abstract: A refrigeration system for a frozen product dispenser is controlled to have a variable cooling capacity that is determined by variable cooling load demands of the dispenser. This is accomplished, in part, by providing the refrigeration system with a variable speed compressor and one or more adjustable expansion valves for metering refrigerant to associated evaporators that are heat exchange coupled to associated freeze barrels of the dispenser, and by controlling the metering setting of the expansion valves and the speed of operation of the compressor in accordance with the cooling load demands of the dispenser. The arrangement provides for efficient operation of the refrigeration system from an energy standpoint and for a reduction in on/off cycling of the system.

Abstract: In a refrigeration system having a pressurizer, a condenser, an expansion device and an evaporator, with the evaporator having an inlet header, an outlet header, and a plurality of channels therebetween, the outlet header has a liquid outlet and a vapor outlet and provision is made for separation of refrigerant liquid from refrigerant vapor. The liquid refrigerant is passed through a superheating heat exchanger to obtain complete evaporation and superheating prior to passing to the pressurizer. Various other features are provided to enhance the system operation.