Abstract: A heat pump system which executes cooling and heating operations of an A2A indoor unit and cooling and heating operations and a hot water operation of an A2W indoor unit in a time division multiplexing (TDM) method, and a control method thereof. Further, the heat pump system solves shortage of a refrigerant during a heating operation of the A2A indoor unit or the A2W indoor unit when the TDM method is used. Therefore, the heat pump system includes a control unit to alternately operate the A2A indoor unit or the A2W indoor unit, upon judging that a simultaneous operating condition of the A2A indoor unit or the A2W indoor unit is satisfied. The heat pump system further includes a refrigerant distribution unit to circulate a refrigerant selectively to the A2A indoor unit or the A2W indoor unit.

Abstract: A refrigerant vapor compression system and a method of controlling the system are adapted for controlling the distribution of cooling capacity between two or more temperature controlled zones.

Abstract: A thermal energy system comprising a first thermal system, the first thermal system in use having a heating and/or cooling demand, a closed loop geothermal energy system comprising a plurality of borehole heat exchangers, each borehole heat exchanger containing a working fluid, and an intermediate heat pump thermally connected between the first thermal system and the geothermal energy system. Each borehole heat exchanger may comprise an elongate tube having a closed bottom end and first and second adjacent elongate conduits interconnected at the bottom end. In particular, the first thermal system is a refrigeration system and the ‘closed loop geothermal energy system provides cooling of the condenser(s) of the refrigeration system.

Abstract: A refrigeration cycle is configured by connecting a compressor that compresses the refrigerant, a four-way valve that switches the circulation path of the refrigerant, a heat source side heat exchanger that exchanges heat, expansion valves that adjust the pressure of the refrigerant, and two or more intermediate heat exchangers that exchange heat between the refrigerant and the heat medium to heat and cool the heat medium, by piping. A heat medium circulation circuit is configured by connecting two or more intermediate heat exchangers, pumps that pressurize the heat medium, two or more use side heat exchangers that exchange heat between the heat medium and the air in the indoor space, and flow path switching valves that switch paths of the heated heat medium or the cooled heat medium to the use side heat exchangers, by piping.

Abstract: An air-conditioning refrigerating system that enables demand control based on operation control of an air-conditioning system and a refrigerating system is provided.

Abstract: The present invention relates to a method for controlling a vehicle air-conditioner, which can prevent undershoot of an evaporator by performing a maximum capacity control or controlling an discharge capacity of a compressor through the outputting of an discharge capacity control value of the compressor directly before the stop of the air conditioner, and can improve the pleasant feelings of the passengers by preventing delay of response, which converges into the target temperature of the evaporator due to the delay of the decrease of the temperature of the evaporator.

Abstract: An object of the present invention is to keep an appropriate amount of a refrigerant to be circulated through a refrigerant circuit and prevent an overload operation of compression means due to high pressure abnormality in a refrigerating apparatus which obtains a supercritical pressure on a high pressure side.

Abstract: A method and system for operating a refrigerant system having a reciprocating compressor with a main cylinder module and an economizer cylinder module includes regulating a flow of refrigerant into the main cylinder module and regulating a flow of refrigerant into the economizer cylinder module. The main cylinder module and the economizer cylinder module have separate inlet and outlet discharge streams. The flow through each module is regulated as a function of an operating mode of the refrigerant system, which includes various modes of loading and unloading based, in part, on a cooling demand. In some embodiments, the refrigerant system may include a connector refrigerant line configured to redirect refrigerant from the economizer cylinder module to the main cylinder module or from the main cylinder module to the economizer cylinder module.

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: An air conditioning apparatus includes a refrigerant circuit, an operation controlling device and a liquid refrigerant accumulation determining device. The refrigerant circuit has an accumulator. The operation controlling device performs normal operation control where each device of the heat source unit and the utilization unit are controlled in accordance with operating load of the utilization unit, and refrigerant quantity determination operation control where properness of quantity of the refrigerant in the refrigerant circuit is determined while performing the cooling operation. The liquid refrigerant accumulation determining device determines whether or not liquid refrigerant is accumulating in the accumulator. When it has been determined that liquid refrigerant is accumulating in the accumulator, liquid refrigerant accumulation control is performed to eliminate liquid refrigerant accumulation in the accumulator.

Abstract: The present invention relates to an aircraft cooling system evaporator arrangement (10) with an evaporation device (20) for exchanging heat between a refrigerant and a coolant, the evaporation device (20) including at least four evaporators (24a, 24b, 24c, 24d) which are hydraulically separate from one another with respect to flow of coolant. The evaporator arrangement (10) further includes at least one feed line (26) for supplying refrigerant to the evaporation device (20). The evaporators (24a, 24b, 24c, 24d) are arranged in such a way that the evaporators (24a, 24b, 24c, 24d) are flowed through pairwise in parallel by refrigerant supplied to the evaporator by the feed line (26). Moreover, two mutually independent circuits (16, 17) for a coolant are provided, each coolant circuit including at least two supply lines (34a, 34c; 36b, 36d) arranged to be hydraulically separate from one another for supplying coolant to, in each instance, one of the evaporators (24a, 24b, 24c, 24d).

Abstract: A refrigerant system detection method for detecting refrigerant systems in an air conditioning system includes a drive step, an operation inhibition step and a recording step. The air conditioning system includes a plurality of indoor units having temperature sensors respectively connected to a plurality of outdoor units. The drive step puts the plurality of outdoor units into a driven state after a start-up time. The operation inhibition step stops or weakens the outdoor units one unit at a time after the drive step. The recording step correlates and records the outdoor units in which operation has been inhibited and the indoor units in which detection values of the temperature sensors have changed as a result of the outdoor units being inhibited. A refrigerant system detection system includes the connected indoor and outdoor units and a management component configured to perform the method. A storage component includes a program to perform the method.

Abstract: An embodiment of the present invention provides an air conditioning system (ACS) for conditioning the airstream entering an air-breathing machine, such as, but not limiting of, a gas turbine. Conditioning may be considered a process that adjusts at least one physical property of the airstream. The physical property may comprise: a wet-bulb temperature, a dry-bulb temperature, relative humidity, density, or the like. In an embodiment of the present invention, the major components of the ACS may be located in a single structure, which may be considered a module. Depending on the application of the ACS, multiple modules may be physically and/or operationally integrated on the air-breathing machine. An ACS may comprise a non-media conditioning system and a media conditioning system. An embodiment of the ACS may provide the flexibility of operating in either an evaporative system mode or a chilling system mode.

Abstract: A climate control system may include a condenser, an evaporator, a compressor, a coolant circuit, and a heat exchanger. The evaporator may be in fluid communication with the condenser. The compressor may be in fluid communication with the condenser and the evaporator and may circulate a first fluid therebetween. The coolant circuit may include an engine, a radiator, and a second fluid circulating between the engine and the radiator. The heat exchanger may include a first fluid conduit and a second fluid conduit. The first fluid conduit may fluidly couple the compressor and the condenser. The second fluid conduit may fluidly couple the radiator and the engine. The heat exchanger may be configured to allow the second fluid to absorb heat from the first fluid.

Abstract: A refrigerant cycle apparatus comprising: a compressor 1, a radiator 2, decompression means 3, a heat absorber 4, an internal heat exchanger 5 that performs heat exchange between a refrigerant at an outlet of said radiator and the refrigerant at an outlet of said heat absorber, wherein first temperature detection means 30 for detecting a refrigerant temperature between an outlet of the compressor 1 and an inlet of the radiator 2 and second temperature detection means 31 for detecting the refrigerant temperature between the outlet of the radiator 2 and a high-pressure side inlet of the internal heat exchanger 5 are provided, and an opening degree of decompression means 3 is controlled so that a temperature difference (?T) between a detection temperature by the first temperature detection means 30 and the detection temperature by the second temperature detection means 31 becomes a target value.

Abstract: A compressor includes a casing accommodating a refrigerant passageway, a compression mechanism and a pipe. The compression mechanism is disposed in the interior of the casing to discharge compressed refrigerant into the refrigerant passageway. The pipe extends from inside of the casing to outside of the casing. The pipe includes two ends. One is a closed end disposed in a predetermined position inside the refrigerant passageway. The other end of the pipe is an opened end disposed outside the casing. The pipe is preferably sized so that a measuring instrument can be inserted into the pipe through the opened end.

Abstract: A refrigerator comprises an enclosure that is cooled below a predetermined temperature, a refrigeration circuit that keeps the temperature of the enclosure below the predetermined temperature, a door that provides access into the enclosure and a pressure equalizing device that equalizes the pressure inside the enclosure with the pressure outside the enclosure. The pressure equalizing device comprises a communication path that fluid-communicates the inside of the enclosure with the outside of the enclosure, and a valve device that opens or closes the communication path. The valve device opens the communication path when the air pressure outside the enclosure is greater than the air pressure inside the enclosure by a predetermined value. The valve device comprises a pivoting plate that is pivoted around a horizontal axis, and an opening that is open to air outside the enclosure. The pivoting plate covers the opening.

Abstract: A refrigeration device includes a control unit, and a refrigerant circuit in which a compression mechanism, a radiator, a refrigerant cooling unit, a first expansion mechanism, a liquid receiver, a second expansion mechanism, and an evaporator are connected in sequence. The control unit performs refrigerant cooling control whereby the refrigerant is cooled by the refrigerant cooling unit so that the state of the refrigerant that has flowed out from the first expansion mechanism is near the saturation line and not near the critical point.

Abstract: Climate control systems are provided that are suitable for providing climate control functionality to a hybrid vehicle. The system is capable of operating in dual modes, depending on the present operational state of the vehicle. For example, the dual modes may be as follows: (1) when the vehicle is currently in transit, including intermittent stops, the climate control system is capable of operating at its maximum output, as requested, for cooling the passenger compartment of the vehicle; and (2) when the vehicle is not in transit (e.g., when parked) the climate control system operates at a reduced capacity in order for the climate control system to be powered by the energy storage device for a set period of time. The climate control system may reduce the capacity based on energy reserve levels in the energy storage device.

Abstract: The invention relates to a command device (13) of a fixed capacity compressor (9) associated with an evaporator through which an air flow passes in an air flow direction (6). The compressor (9) and the evaporator (12) are participating to an A/C loop (8) of an heating, ventilating and/or air conditioning device of a vehicle. The said command device (13) comprises a sensor (15,16) for the measurement of a measured value VM of a characteristic C of a fluid FR,A and comparison means (14) of the measured value VM of the characteristic C of the fluid FR,A with at least two step-values VSmin, VSmax of the characteristic C. The said command device (13) comprises an upstream temperature sensor (20) to be positioned upstream the evaporator (12) according to the air flow direction (6) to measure an upstream temperature T2 of the air flow (3) and give an information (18) which is taken into account by the said command device (13) in order to determine the said step-values VSmin, VSmax of the characteristic C.

Abstract: Alternative means of inhibiting frosting in the interior heat exchanger of a DX system when switching from the heating mode to the cooling mode, plus an improved insulation and heat transfer means for vertically oriented sub-surface geothermal heat transfer tubing, as well as a means to protectively coat the sub-surface metal tubing of a DX system in a corrosive environment.

Abstract: There is provided a refrigerant system 100 including at least one or a plurality of refrigerant flow control devices 125 for regulating operational parameters of the refrigerant system 100, at least one sensor 135, 140 connected to the refrigerant system 100 for monitoring the operational parameters of the refrigerant system 100, and a controller 130.

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: An internal cooling apparatus for automobiles includes a first expansion valve for spraying a coolant to a main evaporator through a high-pressure pipe, a compressor receiving the coolant evaporated in the main evaporator through a low-pressure pipe, a condenser receiving the coolant compressed in the compressor, and a plurality of sub-evaporators each being installed inside of a seat to contact an automobile passenger. One end of each of the sub-evaporators is communicated with the high-pressure pipe and the other end thereof is communicated with the low-pressure pipe such that part of the coolant sprayed through the first expansion valve is supplied to the compressor via each of the sub-evaporators.

Abstract: A vapor compression cooling system having a control unit adapted to receive working fluid pressure or temperature, environment temperature or relative humidity, compressor digital output, or other cooling system information to control a condenser cooling fluid control valve to minimize flow changes through the valve.

Abstract: A refrigeration apparatus includes an air chiller, a storage enclosure defining a compartment, a duct system, and a valve system. The air chiller blows chilled air into the duct system. The compartment has a first and a second opening, each of which is coupled to the duct system. The valve system has valves that can be moved to route the chilled air so that it enters into the first opening and exits the second opening, or vice versa. In one implementation, the first opening is at the top of the compartment and the second opening is at the bottom of the compartment, and the valve system is controlled by a control circuit that periodically switches the valves (via an actuator) to change the direction of the chilled air. This effectively maintains a relatively uniform temperature throughout the compartment.

Abstract: To provide an air conditioning apparatus having a function for extinguishing fire when an electric component assembly ignites. An air conditioning apparatus (1) comprises a vapor compression refrigerant circuit (10) that uses carbon dioxide as a refrigerant, an electric component assembly (26, 46, 56) for controlling an operation for structural devices, and a refrigerant emission pipe (28, 48, 58) capable of emitting carbon dioxide from the refrigerant circuit (10) to the electric component assembly (26, 46, 56).

Abstract: An air conditioning controller includes an air conditioning unit and an evaluating unit. The air conditioning unit determines operation of an air conditioner such that a temperature specified by a user setting matches a vehicle interior temperature. The evaluating unit compares the temperature specified by the user setting and an ideal temperature, and determines, for ecology evaluation, whether the user setting is environmentally friendly. The air conditioning controller compares actual operation of the air conditioner with ideal operation, or changes a threshold for the ecology evaluation or suspends the ecology evaluation in a specific state.

Abstract: A system and process to re-liquefy boil-off liquid natural gas in varied amounts by a process using a screw compressor having an effective compression range from about 10 to about 100 percent of its rated capacity.

Abstract: A refrigeration system can use a flash tank to separate vapor refrigerant from liquid refrigerant. The refrigeration system can include a liquid-refrigerant injection system that can inject liquid refrigerant into an intermediate-pressure location of the compressor. The injected liquid refrigerant can absorb the heat of compression during the compression process. The refrigeration system can include an economizer system that injects a refrigerant vapor into an intermediate-pressure location of the compressor in conjunction with the injection of the cooling liquid. The refrigeration system can incorporate a cooling-liquid injection system that can inject a cooling liquid into an intermediate-pressure location of the compressor.

Abstract: According to one aspect, there is provided a refrigerator including a refrigerating chamber formed at a relatively upper portion of a refrigerator body and a freezing chamber formed at a relatively lower portion of the refrigerator body, which comprises an ice-making chamber which is partitioned in the refrigerating chamber by insulating walls and includes an icemaker for making ice and an ice storage for storing the ice made in the icemaker. The temperature in the refrigerating chamber can be accurately controlled, the loss of cold air can be minimized and the structures for supplying water into the icemaker and the dispenser can be simplified.

Abstract: A compressor includes a shell, a compression mechanism, a motor, a data module, and a compressor controller. The data module includes a processor and a memory. The compressor controller includes a processor and a memory. The data module receives sensed data, stores sensed data in the memory, and communicates sensed data to the compressor controller. The compressor controller controls a capacity of the compressor based on the sensed data and is operable to communicate with a system controller of a refrigeration system.

Abstract: A temperature controlled case is provided that includes an enclosure defining an airspace for receiving products therein, a refrigeration system configured to circulate a refrigerant through an expansion device and at least one cooling element to cool the airspace and a control module having a first predetermined setpoint corresponding to a first cooling mode and a second predetermined setpoint corresponding to a second cooling mode. The control module is configured to determine which one of the first cooling mode and the second cooling mode the refrigeration system is to operate within and to apply the corresponding predetermined setpoint for reference in modulating a position of the expansion device.

Abstract: An objective is to realize an air conditioner in which the amount of consumed electric power can be integrated without using an exclusive electric-power-amount counter, and a control line for measuring the amount of the electric power can be shortened. Commercial electric power is supplied to an outdoor unit 1 and an indoor unit of the air conditioner through a Watt-hour meter 3, for measuring the amount of electric power supplied to the outdoor unit 1 and the indoor unit, having a transmitter for transmitting pulse signals, and through an electric power line 4. The Watt-hour meter 3 and the outdoor unit 1 are communicatively connected to each other through a control line 5. The outdoor unit 1 and the indoor unit are communicatively connected to a centralized controller through a transmission line 7.

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 demand control system for the multi-type air conditioner includes a demand control unit for controlling the operational efficiency of the air conditioners by changing the operation mode of the air conditioners when the estimated wattage exceeds a set wattage while enabling the user to feel more comfortable.

Abstract: Mini, split-system dehumidifier that provides three modes of operation: heating and dehumidification, cooling and dehumidification, and dehumidification only. The dehumidifier maintains a set temperature of the supply air by controlling the amount of heat of rejection at the primary condenser that is cycled back into the supply air.

Abstract: In controlled cooling operation, data on the controlled cooling operation characteristics is read out from a memory and compared with a drop degree of an inside temperature actually measured by an inside temperature sensor 46, and a cooling device is operated so that the inside temperature drops following a temperature curve stored in advance. A state where the inside temperature is higher than the set temperature by 7K or more lasts for 15 minutes, for example, the cooling capacity by the cooling device is increased than the cooling capacity based on control of a controlled operation controller so that even if a door 17 is frequently opened/closed and the inside temperature tends to gradually rise, it can be detected at an early stage and kept close to the set temperature.

Abstract: An automotive air conditioner which is capable of efficiently disposing an internal heat exchanger, and enabling the air conditioner to perform an efficient operation. A thermostatic expansion valve is accommodated in a casing directly connected to the refrigerant outlet of an evaporator. The inlet of the expansion valve and a pipe for receiving high-pressure liquid refrigerant are connected to each other within the casing. The outlet of the expansion valve and the refrigerant inlet of the evaporator are connected to each other within the casing. The internal heat exchanger for performing heat exchange between high-pressure refrigerant delivered to the inlet of the expansion valve and low-pressure refrigerant returning to a compressor is connected between the casing and a pipe joint disposed in a firewall.

Abstract: A method for controlling an electronic expansion valve (EEV) in an air conditioner using a compressor includes the steps of: (a) opening the EEV completely when a power is applied to the air conditioner in stand-by mode; (b) closing the EEV completely when the air conditioner starts a cooling or a heating operation; (c) calculating an indoor heat load; (d) calculating a reference opening pulse frequency of the EEV; and (e) controlling in a stepwise manner an opening pulse frequency of the EEV based on the reference opening pulse frequency of the EEV. The opening pulse frequency of the EEV is controlled in a stepwise manner until it reaches the reference opening pulse frequency of the EEV.

Abstract: An object is to provide a two-stage expansion refrigerating device capable of performing control with low cost so that a pressure of a refrigerant which has flowed through a high-pressure-side expansion unit is an optimum pressure, the device comprises a control unit (a controller) which controls a compressor (a low-stage-side compression element and a high-stage-side compression element) and each expansion unit (a high-pressure-side expansion valve as a high-pressure-side expansion unit and a low-pressure-side expansion valve as a low-pressure-side expansion unit), and a temperature sensor (a temperature detection unit) which detects a temperature of the refrigerant which has flowed through the high-pressure-side expansion valve, and the controller estimates a pressure of the refrigerant which has flowed through the high-pressure-side expansion valve based on a temperature detected by the temperature sensor, and controls one of the high-pressure-side expansion valve and the low-pressure-side expansion valve

Abstract: A light device for refrigerators or freezers includes a sensor, a first manual switch, a rotatable switch, an interior loop and an alternative current power supply. The interior loop includes an interior circuit, an exterior circuit and a control loop. The alternative current power supply is connected to the rotatable switch which is electrically connected the first manual switch and the control loop via the interior circuit. The control loop is electrically connected to a magnetic device and electrically connected to the interior circuit in series. The interior circuit and the exterior circuit are electrically connected in parallel and then both are connected to an earth end of the alternative current power supply. The refrigerator is equipped with functions of automatic light controlled and anti-theft.

Abstract: In a Stirling cycle refrigerator, or in a method for controlling the operation of a Stirling cycle refrigerator, when it starts or stops being operated, or according to the detection result from position or temperature detecting means, the voltage supplied to a driving power source for driving a piston is controlled appropriately to prevent the piston from moving too far out of its movable range and thereby prevent breakage of a component resulting from collision between the piston and a displacer.

Abstract: A system and method for determining thermal performance of a condensing unit includes selecting the condensing unit from a condensing unit database and a compressor from a compressor database. Condensing unit characteristics and compressor characteristics are processed based on simulation points to provide thermal performance data for the condensing unit.

Abstract: A refrigeration system includes a compressor, a gas cooler, an expansion device, and an evaporator. Refrigerant is circulated though the closed circuit system. Preferably, carbon dioxide is used as the refrigerant. As carbon dioxide has a low critical point, systems utilizing carbon dioxide as a refrigerant usually require the refrigeration system to run transcritical. When the system is operating inefficiently, the system is modified so the system operates efficiently. First, a parameter of the system is monitored by a sensor and the then compared to a stored value to determine if the system is operating inefficiently. If the system is operating inefficiently, the system is modified to an efficient system.

Abstract: Fresh air exchange is achieved by uncovering two ports which, respectively, allow stale air to leave the trailer through a high pressure duct and fresh outside air to enter the trailer through a low pressure duct. The trailer end of the ducts are connected to the refrigeration unit evaporator section where the evaporator fan provides the pressure differential. The opposite ends of the ducts are connected to a bracket mounted on the refrigeration unit frame and are exposed to the outside fresh air through a hole in the refrigeration unit's grille when the cover over the ducts has been opened by the linear solenoid under the control of the microprocessor.

Abstract: A refrigeration system includes a compressor, a gas cooler, an expansion device, and an evaporator. Refrigerant is circulated though the closed circuit system. Preferably, carbon dioxide is used as the refrigerant. As carbon dioxide has a low critical point, systems utilizing carbon dioxide as a refrigerant usually require the refrigeration system to run transcritical. When the system is operating inefficiently, the system is modified so the system operates efficiently. First, a parameter of the system is monitored by a sensor and the then compared to a stored value to determine if the system is operating inefficiently. If the system is operating inefficiently, the system is modified to an efficient system.

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: A vapor compression system includes a compressor, a gas cooler, an expansion device, and an evaporator. Refrigerant is circulated through the closed circuit cycle. Preferably, carbon dioxide is used as the refrigerant. Adaptive control is employed to optimize the coefficient of performance of the vapor compression system. As the system changes over time, a model that operates the system is modified. The model is determined by an adaptive control algorithm including variable coefficients. As the model changes, the variables of the adaptive control algorithm change. A control of the gas cooler is then adjusted to regulate the high pressure of the system, and therefore the coefficient of performance. In a first example, Least Mean Squares (LMS) is used to modify the variables of the adaptive control algorithm to optimize the coefficient of performance. In a second example, the coefficient of performance is optimized by a slowly varying periodic excitation method.

Abstract: A refrigeration system including a compressor, condenser, valve, and evaporator in fluid communication; a system controller operable to control one or more aspects of the refrigeration system, and a subsystem controller in communication with the system controller. The subsystem controller is operable to control one of the compressor, condenser, valve, and evaporator. A method of operating the refrigeration system includes communicating a code from the subsystem controller to the system controller, obtaining information at the system controller having a relation to the code; and communicating at least a portion of the obtained information from the system controller to the subsystem controller.