Abstract: An air conditioner (10) includes a refrigerant circuit (20) including a plurality of indoor heat exchangers (27). A controller (1) for controlling operation of the air conditioner (10) includes a change unit (5) configured to change a set temperature Tem to a value larger than a current value when the minimum target superheat degree SHsm of target superheat degrees SHs determined for the respective indoor heat exchangers (27) is higher than a predetermined value SHt.

Abstract: An expansion valve includes a shaft for transmitting the drive force to a valve element and a vibration-proof spring, set between the body and the shaft, which generates the sliding friction by biasing the shaft. The vibration-proof spring includes a spring body of a hollow tube shape, a spring part, which is integrally formed with a side wall of the spring body, and a bulging portion formed on the spring part in a protruding manner such that the tip of the bulging portion is placed opposite to a part of the shaft. When the bulging portion abuts against the shaft inserted to the vibration-proof spring, the spring part is placed in a position along the spring body or is warped outwardly from the spring body, so that the elastically reactive force resulting from the warped spring part allows the shaft to slide in a stabilized manner.

Abstract: A climate control system is provided and may include a compressor, a first heat exchanger in fluid communication with the compressor, a second heat exchanger in fluid communication with the compressor and the first heat exchanger, and a third heat exchanger disposed between the first heat exchanger and the second heat exchanger. A conduit may be fluidly coupled to the third heat exchanger and the compressor and may selectively supply fluid to the compressor. A valve may control a volume of fluid supplied to the compressor via the conduit and a controller may control the valve based on a discharge temperature of the compressor and a super heat temperature of the third heat exchanger.

Abstract: A system and method for monitoring an overheat condition of a compressor is provided. A compressor connected to an evaporator. A suction sensor outputs a suction signal corresponding to a temperature of refrigerant entering the compressor. A control module is connected to the evaporator sensor and the suction sensor and determines an evaporator temperature, calculates a suction superheat temperature based on the evaporator temperature and the suction signal, and monitors an overheat condition of the compressor by comparing the suction superheat with a predetermined suction superheat threshold.

Abstract: A method for controlling a supply of refrigerant to an evaporator (5) of a vapour compression system (1), such as a refrigeration system, an air condition system or a heat pump, is disclosed. The vapour compression system (1) comprises an evaporator (5), a compressor (2), a condenser (3) and an expansion device (4) arranged in a refrigerant circuit. The method comprises the steps of: Actuating a component, such as an expansion valve (4), a fan or a compressor (2), of the vapour compression system (1) in such a manner that a dry zone in the evaporator (5) is changed; measuring a temperature signal representing a temperature of refrigerant leaving the evaporator (5); analysing the measured temperature signal, e.g.

Abstract: The degree-of-opening of an expansion valve is set to an appropriate degree-of-opening regardless of the load and external conditions for a heat-source unit. In a turbo refrigerator including a compressor that compresses a refrigerant; a condenser that condenses a compressed refrigerant by means of cooling water; an evaporator that evaporates a condensed refrigerant and also performs heat exchange between this refrigerant and cold water; and an expansion valve that causes a liquid-phase refrigerant retained in the condenser to expand, a expansion-valve control device (40) controls a degree-of-opening of the expansion valve (18).

Abstract: A refrigerant vapor compression system includes a compressor, an expansion valve, a compressor speed sensor operatively connected to the compressor, an ambient temperature sensor, and a controller operatively coupled to the expansion valve, compressor speed sensor and ambient temperature sensor. The controller including a superheat control that is configured and disposed to selectively activate the expansion valve to establish a desired superheat value based on a speed of the compressor as sensed by the compressor speed sensor and ambient temperature as sensed by the ambient temperature sensor.

Abstract: An air conditioner includes a compressor, a first heat exchanger, and a first pipe configured to allow refrigerant to flow from the first heat exchanger. A bypass pipe is branched off from the first pipe and is configured to expand refrigerant flowing through the bypass pipe. A second heat exchanger is configured to allow the expanded refrigerant of the bypass pipe to heat-exchange with the refrigerant flowing along the first pipe. A second pipe couples the second heat exchanger to the compressor so that the refrigerant expanded by the bypass pipe and heat-exchanged at the second heat exchanger can be introduced into the compressor.

Abstract: A variable flow refrigerant system having a compressor and one or a plurality of evaporators. The suction at one or the plurality of evaporators for the input to the compressor is monitored and generally corresponds to the minimum pressure of the refrigerant. The pressure is associated with a temperature and is controlled to always be above the dew point temperature of the room.

Abstract: The subject of the invention is a device (5) for expanding a refrigerant fluid comprising, on the one hand, a first inlet (8) of the expansion device and a first outlet (9) of the expansion device which are connected by a first refrigerant circulation duct (11), the first refrigerant circulation duct (11) comprising an upstream part (22) and a downstream part (25) which parts are placed in communication by a first communication passage (18) and, on the other hand, a second inlet (12) of the expansion device and a second outlet (13) of the expansion device which are connected by a second refrigerant circulation duct (14).

Abstract: A refrigerated transport system has a container, a generator system, and a refrigeration system. The refrigeration system is electrically coupled to the generator to receive electric power and thermally coupled to the container. The refrigeration system includes an electrically powered compressor. A condenser is downstream of the compressor along a refrigerant flowpath. An expansión device is downstream of the compressor along the refrigerant flowpath. An evaporator is downstream of the expansión device along the refrigerant flowpath. A controller is coupled to the expansión device to control operation of the expansión device. The controller is configured to opérate the expansión device to control an evaporator superheat. The evaporator superheat is to be relatively high for a set temperature of a first valué associated with non-frozen perishables.

Abstract: A refrigeration system is provided with an ice maker chamber within a fresh food compartment. The refrigeration system includes a refrigeration path and an ice maker path. The ice maker path includes an electronic expansion valve for controlling the refrigerant entering an ice maker evaporator and an evaporator pressure regulator. Controlling the refrigeration system includes the steps of sensing a first refrigerant temperature at an exit of the ice maker evaporator and controlling a first control of the electronic expansion valve until the temperature reaches a temperature target. The method of controlling can further include comparing a slope of the temperature to at least one of a minimum, a target, or a maximum setting to adjust the control. Subsequently, a second control for the electronic expansion valve can be repeatedly adjusted by evaluating the first refrigerant temperature and the slope.

Abstract: In a refrigerating cycle apparatus and control method thereof, a controller sets a high-pressure pressure target value from thermal load and temperature conditions based on refrigerant information that has been obtained from detectors, and controls at least one of a rotational frequency of a compressor, a degree of opening of an electronic expansion valve, a rotational frequency of an outdoor fan, or a rotational frequency of an indoor fan to match a high-pressure pressure to the high-pressure pressure target value that has been set. Here, a threshold value is set when the high-pressure pressure target value is set, and a method for setting the high-pressure pressure target value is modified depending on whether the high-pressure pressure is greater than or equal to the threshold value or less than the threshold value when the high-pressure pressure target value is decided.

Abstract: To provide a temperature sensing tube for an expansion valve in which a hunting can be prevented by slowing of a temperature reaction rate of an expansion valve, a ceramic sintered member serving as a heat transfer delay member (3) in a temperature sensing tube (1) is fixed so as not to directly contact with a tubular member (2) by fixing springs (4, 4) provided at both end portions (13, 13), whereby a heat transfer from the tubular member (2) to the ceramic sintered member becomes slow, temperature is not transferred from a mated piping directly via the tubular member, whichever outer surface of the temperature sensing tube 1 contacts with the piping, and a reaction rate with respect to a temperature rise of the expansion valve can be made slow.

Abstract: Out of switching mechanisms (30A, 30B), the switching mechanism (30A) connected to an indoor heat exchanger (41) performing a heating operation is configured so that the opening of a supercooling control valve (53) is adjusted according to the air conditioning load of another indoor heat exchanger (41) performing a cooling operation downstream of a liquid connection pipe (13) connected to the former indoor heat exchanger (41).

Abstract: A method for controlling a refrigeration system with a variable compressor capacity, and at least two refrigeration entities, e.g. display cases, includes controlling suction pressure by either permitting or preventing the flow of refrigerant into the evaporators of one or more refrigeration entities. The method also includes controlling compressor capacity based on a signal derived from one or more properties of the one or more refrigeration entities, said signal reflecting a possible difference between the current compressor capacity and a current refrigeration demand of the refrigeration system. The method reduces wear on compressors by avoiding switching them ON or OFF to the largest extent possible, and also prevents problems relating to conflicting control strategies due to control parameters, e.g. suction pressure, being determined based on two or more controllable parts, e.g. compressors and flow of refrigerant into refrigeration entities.

Abstract: An electronic expansion valve (EEV) is employed in refrigeration systems to regulate the flow of refrigerant through an evaporator. The position of the EEV is controlled through a first control loop that generates a first position signal based on superheat feedback associated with the refrigeration system, and a second control loop that generates a second position signal based on pressure feedback associated with the refrigeration system. The larger of the first position signal and the second position signal is selected to control the position of the EEV value, and the selected position signal is provided in feedback to both the first control loop and the second control loop.

Abstract: An electrically controlled expansion valve package (10) comprises an expansion valve (30), sensors (32, 33, 36) and control electronics (35) all included in a monolithic package that greatly simplifies installation, while also enabling performance enhancements. The expansion valve is controlled by control electronics that, among other things, determines from pressure and temperature sensors the type or nature of the refrigerant being used in the refrigeration system for adapting control of the expansion valve to the refrigerant.

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: A control system for an expansion valve and evaporator of an air conditioner system is provided that comprises an expansion valve having a valve element that is movable relative to a valve port for varying an opening area to regulate the flow of refrigerant to an evaporator coil. The evaporator coil has an inlet and an outlet, and is configured to conduct heat to a refrigerant flowing through the evaporator coil, where the exiting refrigerant temperature is dependent on the refrigerant flow rate. The control system for controlling the expansion valve includes an evaporator coil outlet temperature sensor, which is configured to sense the temperature of refrigerant within the evaporator coil near the outlet of the evaporator coil. A controller is in communication with the evaporator coil outlet temperature sensor for sensing temperature of refrigerant near the evaporator outlet, and is configured to determine a control set point based on the refrigerant temperature near the evaporator outlet.

Abstract: After a chiller unit is started, an opening command of 10 pulses is output to an electronic expansion valve, and after a predetermined period of time (at the time of starting with unload) elapses, an opening command of 100 to 150 pulses is output to open the electronic expansion valve up to a predetermined opening degree. Thereafter, a discharge side refrigerant super-heat TdSH is monitored and a closing command of 1 pulse/sec is output to the electronic expansion valve to drive the same in a closing direction in a short time until TdSH becomes 20 K. After TdSH has reached 20 K, a closing command of 1 pulse/3 sec is output to the electronic expansion valve, until TdSH becomes 25 K, to drive the electronic expansion valve 3 at a smaller speed in the closing direction than that speed in the closing direction until TdSH becomes 20 K.

Abstract: A method is provided for controlling an intermittently supercritically operating refrigeration circuit. A control valve (12) is controlled: (a) in the subcritical mode, so that a predetermined “subcritical pressure” ensuring a predetermined sub-cooling of the liquid refrigerant at the outlet (14) of a heat-rejecting heat exchanger (10) is maintained; (b) in the supercritical mode, so that a predetermined “supercritical pressure”, which is optimized for optimum efficiency, of the supercritical refrigerant at the outlet (14) of the heat-rejecting heat exchanger (10) is maintained; and (c) in a border mode in a border region next to the critical point, dependent on a “continuity pressure” which is determined on the basis of the predetermined “subcritical pressure” and the predetermined “supercritical pressure” of steps (a) and (b).

Abstract: A vapor compression refrigeration system including components capable of determining the superheat at a compressor inlet is provided. The vapor compression refrigeration system may include sensors capable of making measurements from which the superheat at the compressor inlet may be determined. The vapor compression refrigeration system may be operable to compare the determined superheat level at the inlet to the compressor to a desired superheat level and generate a new evaporator discharge superheat level target for one or more evaporators operatively interconnected to the compressor to affect the superheat at the compressor inlet. The vapor compression refrigeration system may be operable to broadcast the new evaporator discharge superheat level target to the one or more evaporators over a communications bus. The vapor compression refrigeration system may update and broadcast the evaporator discharge superheat level target at programmed intervals.

Abstract: A vapor compression air conditioning system includes a motor operated expansion valve and control unit including sensors for determining the amount of superheat of the working fluid at or adjacent to the compressor inlet. Expansion valve position is adjusted to maintain a predetermined amount of superheat. The sensors may sense working fluid evaporator temperature and temperature downstream of the evaporator. Dual motor operated expansion valves may be disposed in the working fluid conduit between the heat exchangers in a reversible system. In operation, the expansion valve position may be set as a function of ambient temperature, a previous position, and predetermined superheat requirements to minimize liquid ingestion by the compressor.

Abstract: A method of reducing a cyclical loss coefficient of an HVAC system efficiency rating of an HVAC system includes operating the HVAC system using a recorded electronic expansion valve position of an electronic expansion valve of the HVAC system, discontinuing operation of the HVAC system, and resuming operation of the HVAC system using an electronic expansion valve position that allows greater refrigerant mass flow through the expansion valve as compared to the recorded electronic expansion valve position.

Abstract: A modular evaporator which can be assembled from a number of standard modules is provided. Depending on the requirements, the modular evaporator can be assembled to meet a wide range of design cooling loads. Additionally, the modular evaporator is capable of generating and holding ice for thermal storage purposes, eliminating the need for external ice storage tanks. Furthermore, the heat transfer and thermal storage fluid for the evaporator can simply be water which considerably simplifies the system, lowers the cost, and increases the efficiency of the heat transfer loop.

Abstract: In a refrigerating air conditioning system using refrigerant such as CO2 used in a supercritical area, a highly efficient refrigerating air conditioning system is provided by adjusting the amount of refrigerant in a radiator which contributes to the efficiency of the system stably and quickly. During heat utilizing operation, the superheat at the exit of an evaporator is controlled to a predetermined value by controlling the opening of an expansion valve provided on the upstream side of the evaporator, and an expansion valve is controlled so that the state of refrigerant in a connection pipe on the high-pressure side becomes a supercritical state. In this state, a flow rate control valve is controlled to change the density of the refrigerant stored in a refrigerant storage container and the amount of refrigerant existing in the radiator is adjusted.

Abstract: A direct exchange geothermal heating/cooling system has a self-adjusting expansion valve and a bypass flow path to improve efficiency when the system operates in a heating mode. The expansion valve may operate based solely on pressure from the vapor refrigerant transport line. The system may alternatively include an accumulator, a compressor, and an oil separator, wherein an oil return line returns oil from the oil separator to the accumulator. Additionally, a direct exchange geothermal heating/cooling system may include a hot-gas bypass valve for diverting heated vapor refrigerant to the liquid refrigerant line. Finally, a direct exchange geothermal heating/cooling system having a sub-surface heat exchanger extending to a depth of at least 300 feet may use a refrigerant particularly suited for such an application.

Abstract: A control method regulates an electronic expansion valve of a chiller to maintain the refrigerant leaving a DX evaporator at a desired or target superheat that is minimally above saturation. The expansion valve is controlled to convey a desired mass flow rate, wherein valve adjustments are based on the actual mass flow rate times a ratio of a desired saturation pressure to the suction pressure of the chiller. The suction temperature helps determine the desired saturation pressure. A temperature-related variable is asymmetrically filtered to provide the expansion valve with appropriate responsiveness depending on whether the chiller is operating in a superheated range, a saturation range, or in a desired range between the two.

Abstract: A refrigerant system has at least one unloader valve selectively communicating refrigerant between the compressor compression chambers and a point upstream of the evaporator. When the compressor is run in unloaded mode, partially compressed refrigerant is returned to a point upstream of the evaporator. In an unloaded mode, a higher refrigerant mass flow rate passes through the evaporator, as compared to prior art where the by-passed refrigerant was returned downstream of the evaporator. This increases system efficiency by more effectively returning oil which otherwise might be left in the evaporator back to the compressor. Also, the amount of refrigerant superheat entering the compressor in unloaded operation is reduced as compared to the prior art compressor systems, wherein the by-passed refrigerant is returned directly to the compressor suction line. Reduced refrigerant superheat increases system efficiency, improves motor performance and reduces compressor discharge temperature.

Abstract: Refrigeration circuit (2) for circulating a refrigerant in a predetermined flow direction, having in flow direction a heat rejecting heat exchanger (4), an evaporator throttle valve (8), an evaporator (10), a compressor (22), an internal heat exchanger (16) placed with its “cool side” between the evaporator (10) and the compressor (22), an inlet temperature sensor (24) located between the evaporator (10) and the internal heat exchanger (16) and an outlet temperature sensor (26) located between the internal heat exchanger (16) and the compressor (22), and a control (28) for controlling the evaporator throttle valve (8) based on the inlet and outlet temperature sensor measurement, wherein the control is adapted for controlling the evaporator throttle valve (8) based on an inlet temperature setpoint at the inlet temperature sensor (24); and shifting the inlet temperature setpoint based on the outlet temperature sensor measurement (26).

Abstract: An ejector cycle system with a refrigerant cycle through which refrigerant flows includes an ejector disposed downstream of a radiator, a first evaporator located to evaporate refrigerant flowing out of the ejector, a branch passage branched from a branch portion between the radiator and a nozzle portion of the ejector and coupled to a refrigerant suction port of the ejector, a throttling unit located in the branch passage, and a second evaporator located downstream of the throttling unit to evaporate refrigerant. In the ejector cycle system, a variable throttling device is located in a refrigerant passage between a refrigerant outlet of the radiator and the branch portion to decompress the refrigerant flowing out of the radiator.

Abstract: An air conditioning apparatus includes a refrigerant circuit and an operation control section. The operation control section is capable of performing a refrigeration cycle for causing an outdoor heat exchanger to function as a refrigerant condenser and an indoor heat exchanger to function as a refrigerant evaporator, while performing superheat degree control for controlling the aperture of an indoor expansion valve so that the degree of superheat of the refrigerant at the outlet from the indoor heat exchanger is constant. The operation control section means sets a lower aperture limit for the indoor expansion valve to perform the superheat degree control, and reduces the lower aperture limit when the refrigerant at the outlet from the indoor heat exchanger is detected to be wet.

Abstract: A refrigeration device includes a control device and a multiple cooling elements. A supply header delivers refrigerant to the cooling elements and a return header returns refrigerant from the cooling elements. A single pressure sensor provides a signal representative of a pressure of the refrigerant in the return header to the control device, and a single temperature sensor provides a signal representative of a temperature of the refrigerant in the return header to the control device. The control device provides an output signal to control each of the cooling elements, in response to the signals from the single temperature sensor and the single pressure sensor.

Abstract: The invention relates to an expansion valve, in particular for a vehicle air-conditioning system operated with cooling medium, with a valve seat (37) and a valve-closing element (39), which closes a passage opening (44) between a cooling medium inlet opening (14) and a cooling medium outlet opening (16), and with an actuating device (46) which acts on the valve-closing element (39) and opens and closes the passage opening (44), a shortened maximum working lift for opening the valve-closing element (39) out of the valve seat (37) being provided, at which a ball seat cross section formed between valve-closing element (39) and valve seat (37) is designed to be smaller than an annular gap cross section formed between a transmission pin (47) of the actuating device (46) and a passage opening (44).

Abstract: A control apparatus and associated method for a refrigeration system are provided. The control apparatus includes sensors capable of detecting controlled refrigerator zone temperatures and superheat levels of refrigerant vapour exiting an evaporator. The control module receives input from the sensors, compares the input to a determined controlled refrigerator zone set point and a learned superheat level, and generates an output with respect thereto. In particular the output modulates an electronic evaporator pressure regulating (EEPR) valve between an open and a closed position in response to detecting abnormal operation of the thermostatic expansion valve or electronic expansion valve.

Abstract: By studying or storing refrigerating cycle characteristics of an air conditioning apparatus at the normal time and comparing them with refrigerating cycle characteristics acquired from the air conditioning apparatus at the time of operation, it becomes possible to exactly and accurately diagnose normality or abnormality of the air conditioning apparatus under any installation conditions and environmental conditions, which eliminates operations of inputting a difference between apparatus model names, a piping length, a height difference, etc at the time of apparatus installation. Accordingly, it aims at shortening the time of judging normality or abnormality, and improving the operability.

Abstract: A subcool flow control valve useful in a refrigerant system includes an enclosure having a fluid flow pathway for a controlled fluid between an inlet and an outlet. A thermally conductive flexible wall forms a sealed cavity within the enclosure for carrying a controlling fluid. A metering orifice operable between the pathway and the outlet port controls an amount of metered fluid passing through the outlet port in response to movement of the flexible wall toward and away from the metering orifice in response to temperature changes of the controlled fluid transmitting temperature and thus pressure changes to the controlling fluid in the sealed cavity. Inverse thermal feedback means is formed as part of the valve for stabilizing valve operation thus providing means for transmitting a thermal signal from the metered controlled fluid back to the controlling fluid.

Abstract: A fluid system that includes a flow system for a liquid having an inlet, an outlet, at least one fluid line extending from the inlet to the outlet and an electrically activatable melting device, wherein activation of the melting device causes melting, which interrupts, stops or diverts a flow of the fluid through the flow system. In one embodiment, the fluid system may be used in a device for measuring blood sugar.

Abstract: A modular evaporator which can be assembled from a number of standard modules is provided. Depending on the requirements, the modular evaporator can be assembled to meet a wide range of design cooling loads. Additionally, the modular evaporator is capable of generating and holding ice for thermal storage purposes, eliminating the need for external ice storage tanks. Furthermore, the heat transfer and thermal storage fluid for the evaporator can simply be water which considerably simplifies the system, lowers the cost, and increases the efficiency of the heat transfer loop.

Abstract: An air conditioning system is able to decrease the amount of refrigerant between a first expansion device and an injection valve and thus adjust the pressure of an injected refrigerant by decreasing the opening degree of the first expansion device and maintaining the opening degree of a second expansion device upon opening of the injection valve, thereby making the system stable upon opening of the injection valve. Furthermore, upon starting up a compressor, the opening degrees of the first and second expansion devices are partly decreased based on the start-up of the compressor and then gradually opened again, and upon completion of the start-up of the compressor, the opening amounts of the first and second expansion devices and the injection valve are controlled, thereby making the cycle more stable.

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 evaporator for evaporating the refrigerant discharged from the expander, 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. When the compressor is stopped, the controller controls the refrigerant flow regulator to reduce the amount of refrigerant flowing into the expander.

Abstract: A humidity control system (10) includes a refrigerant circuit (50) including a compressor (53), a first adsorption heat exchanger (51) carrying an adsorbent thereon, an expansion valve (55) adjustable in opening and a second adsorption heat exchanger (52) carrying an adsorbent thereon, supplies humidity-controlled air to a room by operating alternately in a first batch mode in which the second adsorption heat exchanger (52) adsorbs moisture in air and the first adsorption heat exchanger (51) releases moisture to air and a second batch mode in which the first adsorption heat exchanger (51) adsorbs moisture in air and the second adsorption heat exchanger (52) releases moisture to air, and controls the opening of the expansion valve (55), when a valve control start time has come a predetermined time after the start of each batch mode, so that the degree of superheat of refrigerant in the refrigerant circuit (50) reaches a predetermined value.

Abstract: A refrigerant expansion valve for a refrigerant system includes a main body, a motor and first and second members. The main body has a refrigerant flow passage that extends therethrough. The first and second members are connected together and are configured with threads that have a different pitch to allow for relative movement between both members and the main body. The motor is positioned adjacent the main body and is coupled to the first member. The motor actuates the first member in response to control signals to move the second member within the main body to modulate the flow of refrigerant through the refrigerant flow passage.

Abstract: A system includes a compressor temperature sensor that generates a compressor discharge temperature signal corresponding to a compressor of a refrigeration system, a compressor pressure sensor that generates a compressor discharge pressure signal corresponding to the compressor, and a controller processing the signals over a predetermined time period. The processing includes calculating a discharge saturation temperature based on the compressor discharge pressure signal, calculating compressor superheat data based on the compressor discharge temperature signal and the discharge saturation temperature, accumulating the compressor superheat data over the predetermined time period, and comparing the accumulated compressor superheat data to a predetermined threshold. The controller generates an alarm indicating a compressor fault based on the comparing.

Abstract: A refrigeration apparatus includes a condensing unit, a flow distributor, and an evaporator connected to the condensing unit via the flow distributor. A pressure detector is configured to detect condensation pressure of the refrigerant. A calculation unit is configured to calculate a target condensation pressure of refrigerant necessary for the refrigerant to be an evaporation temperature in the evaporator. A controller is configured to control the condensing unit so that the condensation pressure of the refrigerant becomes equal to or more than the target condensation pressure.

Abstract: A compression refrigeration system and evaporator having multiple circuits. Spray nozzles are provided for atomization and expansion of the refrigerant. The atomizing spray nozzles are interposed in each evaporator circuit and the nozzles are sized to distribute atomized refrigerant to the various evaporator circuits based on airflow rates across the associated circuit.

Abstract: A refrigerant system is provided with a control for its expansion device. The control operates the expansion device to adjust the superheat of the refrigerant leaving an evaporator to have desired dehumidification for air being delivered into an environment to be conditioned.

Abstract: If the degree of opening of an electronic expansion valve (14) is kept below a specified degree of opening or if the degree of superheat of refrigerant at an evaporator (15) side is kept above a specified degree of superheat, the amount of circulating refrigerant is judged to be insufficient. Thus, the volume of an air delivered by an evaporator fan (22) is reduced.

Abstract: A control procedure operates an expansion valve of an air conditioning system. The control procedure utilizes a first control procedure to bring a calculated superheat value within a range of a target superheat value, and a second control procedure to cause the calculated superheat value to match the target superheat value. Both the first and second control procedures preferably use Proportional, Integral, Derivative control algorithms.