Abstract: A compressor inlet pressure estimation apparatus for a refrigeration cycle system is disclosed. An electronic control unit 14 answers YES by judging that the command to start a compressor 2 is issued when an air-conditioning switch is turned on in step S100. After that, the electronic control unit 14 answers NO in the case where a timer count time Tc is shorter than a predetermined time T1 in step S120. At the same time, Tefin_C is set to 15° C. in step S130. The lower one of Tefin_C and Tefin determined in this way is determined as Tefin_d (step S150). After that, Tefin_d is input to the first-order lag function to acquire Tefin_AD(N). Then, the control proceeds to step S170, where the estimated value Ps_es(N) of the refrigerant inlet pressure of the compressor 2 is determined using Tefin_AD(N) and Gr.

Abstract: A compressor drive torque estimating device to be adapted for a system provided with a refrigeration cycle in which a refrigerant is circulated by a compressor driven by a drive source mounted in a vehicle, comprising heat load detecting means for detecting a heat load of the refrigeration cycle, a storage unit storing a plurality of estimated drive torque characteristics establishing correlation between a drive torque change characteristic of the compressor and an elapsed time from a time of start of operation of the compressor, an estimated drive torque characteristic selecting means for selecting the one of the plurality of estimated drive torque characteristics stored in the storage unit based on detected values detected by the heat load detecting means, and an estimated drive torque calculating means for calculating an estimated drive torque of the compressor based on the estimated drive torque characteristic selected by the estimated drive torque characteristic selecting means.

Abstract: An air conditioner that acquires energy from a high pressure gas includes a gas storage device, a pneumatic engine, a compressor, a cooling system, and a control module. The gas storage device supplies the high pressure gas. A duct guides the high pressure gas into an engine room of the pneumatic engine. The pneumatic engine transforms the high pressure gas into a kinetic energy for output. The compressor is connected to a kinetic energy output of the pneumatic engine. The pneumatic engine drives the compressor to circulate a refrigerant within the cooling system.

Abstract: A refrigerant discharge capacity of a high-pressure side compression mechanism and a refrigerant discharge capacity of a low-pressure side compression mechanism can be independently controlled, in a two-stage pressurizing refrigeration cycle device. The refrigerant discharge capacity of the low-pressure side compression mechanism is determined based on an outside air temperature, an air temperature at the evaporator, and a preset temperature. Furthermore, the refrigerant discharge capacity of the high-pressure side compression mechanism is determined based on the determined refrigerant discharge capacity of the low-pressure side compression mechanism such that an effective capacity ratio is not less than 1 nor more than 3. Therefore, in the two-stage pressurizing refrigeration cycle device, COP can be improved with a simple structure and control.

Abstract: A cooling system has a plurality of separate cooling stages including an upstream cooling stage having an upstream cooling circuit and a downstream cooling stage including a downstream cooling circuit, which are each a direct expansion cooling circuit including a tandem compressor. Each tandem compressor includes a fixed capacity compressor and a variable capacity compressor. A controller controls the fixed capacity compressor and variable capacity compressor of each tandem compressor based on a Call for Cooling, which of a plurality of ranges the Call for Cooling falls within, and whether the Call for Cooling is ramping up or ramping down.

Abstract: A cooling system has a cabinet and a plurality of separate cooling stages including an upstream cooling stage and a downstream cooling stage. At least the upstream cooling state is a variable capacity cooling stage. Each cooling stage has a cooling circuit. Evaporators of the cooling circuits are arranged in the cabinet so that air passes over them in serial fashion. A controller when a Call for Cooling first reaches a point where cooling is needed, operating the upstream cooling circuit to provide cooling and not the downstream cooling circuit. When the Call for Cooling has increased to a second point, the controller additionally operates the downstream cooling circuit to provide cooling. The cooling capacity at which the upstream cooling circuit is being operated is less than its full capacity when the Call for Cooling reaches the second point.

Abstract: Disclosed are a compressor control device, a method for controlling a compressor, and a refrigerator including the same. The present invention enables: a compressor to be driven by using a mode selectively to be driven by an inverter and a mode which directly uses a supply voltage, according to the quality of electricity of the supply voltage; loss which is caused by the use of the inverter to be reduced or removed by directly providing the supply voltage to the compressor within a certain voltage or frequency range; and increased energy efficiency by reducing power consumption.

Abstract: A refrigerant system is provided with a suction pulse width modulation valve, and a pulse width modulation control for controlling this valve. System pressures, such as the pressure on the evaporator and the condenser are monitored. The measured system pressures are maintained within a band of acceptable lower and upper limits. As the pulse width modulation control cycles the valve, the refrigerant pressures in the evaporator and the condenser tend to fluctuate. The control ensures those fluctuations are within the limits by controlling the duty cycle of the valve.

Abstract: Vehicle cooling fan control system and method which prevent an occupant from hearing peculiar sounds from a cooling fan due to a decrease in rotation speed are provided. The vehicle cooling fan control system according to the present invention is configured not to stop the rotation of a fan motor for a predetermined time even upon satisfaction of an air conditioner stoppage condition as long as a vehicle interior is quiet.

Abstract: According to a method of controlling a refrigerator in accordance with the present invention, after the refrigerating chamber and the freezing chamber are operated at the same time, refrigerant recovery is performed and the refrigerating chamber is then cooled. Accordingly, imbalance due to the pressure difference between the refrigerating chamber evaporator and the freezing chamber evaporator can be solved. Further, there is an advantage in that the refrigerating chamber can be cooled rapidly since refrigerant is supplied to the refrigerating chamber smoothly.

Abstract: An air conditioning apparatus and a control method thereof are provided. The air conditioning apparatus includes a first switch valve, a compressor, a decompression element, a second switch valve, a condenser, and an evaporator. The control method of an air conditioning apparatus includes steps of setting a preset temperature, measuring an indoor temperature, and comparing the preset temperature with the indoor temperature. When the indoor temperature is lower than the preset temperature, the first switch valve and the second switch valve are turned on and the compressor is turned off; and when the indoor temperature is higher than the preset temperature, the first switch valve and the second switch valve are turned off and the compressor is turned on.

Abstract: A cooling system for cooling food on board an aircraft includes a cooling circuit adapted to supply cooling energy to at least one cooling station, a refrigerant circulating in the cooling circuit selected such that it is convertible at least partially from the liquid to the gaseous state of aggregation on releasing its cooling energy to the at least one cooling station and subsequently convertible back at least partially to the liquid state of aggregation again by an appropriate pressure and temperature control in the cooling circuit, and a refrigerant container including a receiving space arranged in an interior space of the refrigerant container which receives the refrigerant circulating in the cooling circuit, the receiving space of the refrigerant container connected to the cooling circuit by a flow line for discharging the refrigerant from the receiving space and by a return line for returning the refrigerant into the receiving space.

Abstract: A method for controlling torque of an air conditioner compressor is disclosed. In one example, the air conditioner compressor is a variable displacement compressor. The method may provide smooth transitions between different air conditioner compressor torques.

Abstract: Assemblies for HVAC systems and methods of operating HVAC systems are disclosed, including a method of operating an HVAC system having a condenser motor operatively coupled to a fan and a controllable bus voltage for powering the condenser motor. The method includes increasing the controllable bus voltage from a first voltage to a second voltage to increase a speed of the condenser motor.

Abstract: A space-saving, high-density modular data pod system and an energy-efficient cooling system are disclosed. The modular data pod system includes a central free-cooling system and a plurality of modular data pods, each of which includes a heat exchange assembly coupled to the central free-cooling system, and a distributed mechanical cooling system coupled to the heat exchange assembly. The modular data pods include a data enclosure having at least five walls arranged in the shape of a polygon, a plurality of computer racks arranged in a circular or U-shaped pattern, and a cover to create hot and cold aisles, and an air circulator configured to continuously circulate air between the hot and cold aisles. Each modular data pod also includes an auxiliary enclosure containing a common fluid and electrical circuit section that is configured to connect to adjacent common fluid and electrical circuit sections to form a common fluid and electrical circuit that connects to the central free-cooling system.

Abstract: An air-conditioning system for vehicle temperature control incorporates a thermostat having contacts, and a circulation contour, including a condenser, an expansion valve essentially connected with the condenser, an evaporator connected sequentially with the expansion valve, a first tee splitter connected to a common line, a second tee splitter connected to the condenser, a main compressor connected with the first tee splitter and with the second tee splitter, a supplemental compressor connected with the first tee splitter and the second tee splitter. The supplemental compressor is operatively controlled by the thermostat and powered by a supplemental battery. In embodiments, the supplemental compressor is electrically connected with the supplemental battery and operatively controlled by a control circuitry including a power relay, an air-condition relay, and the contacts of thermostat. The proposed system reduces pollutions and saves energy.

Abstract: A refrigerator is disclosed herein. The refrigerator may include a compressor to compress a refrigerant, a condenser to condense the refrigerant passed through the compressor, a capillary tube that lowers a temperature and pressure of the refrigerant passed through the condenser, an evaporator to evaporate the refrigerant passed through the capillary tube, a thermal storage device for auxiliary cooling that undergoes heat exchange with the refrigerant to store thermal energy, an energy management device that receives electric rate information, and a controller configured to control the compressor based on the electric rate information received at the energy management device. The controller may control an operation of the thermal storage device to provide auxiliary cooling for the refrigerator when the compressor is not operational or when electric rates are relatively high.

Abstract: Control device for an electric compressor and a start control method of an electric compressor that can smoothly and reliably start the electric compressor even at high temperature. Even in a high temperature state of a power transistor, a rotational speed or an acceleration rate of a motor according to the temperature is set to gradually start the electric compressor. After the commencement of the start, the temperature of the power transistor is repeatedly checked for every predetermined time to update the rotational speed or the acceleration rate of the motor, and the rotational speed or the acceleration rate of the motor is increased according to the temperature of the power transistor, thereby allowing quick start.

Abstract: A refrigerator capable of having a storage compartment configured for a converted use as a freezing compartment or a refrigerating compartment includes a refrigerating compartment; a converting compartment configured for a variable use among freezing, refrigerating, and off; a cold air flow supplying apparatus having a compressor, a condenser, an evaporator, an expanding valve, a draft fan, a cold air flow supplying apparatus; a converting damper apparatus installed at the converting compartment discharging flow path for controlling the supply of the cold air flow to the converting compartment; and a refrigerating compartment damper apparatus installed at the refrigerating compartment discharging flow path for controlling the supply of the cold air flow to the refrigerating compartment.

Abstract: A refrigerant system is provided that includes a compressor, a motor for driving the compressor, a refrigerant system component, and a controller. The refrigerant system component can operate in a pulse width modulated mode having a loaded phase and an unloaded phase. The compressor motor is loaded in the loaded phase but unloaded in the unloaded phase. The controller applies a first voltage to the compressor motor in the loaded phase and a second voltage to the compressor motor in the unloaded phase. Here, the second voltage is less than the first voltage.

Abstract: A refrigeration cycle apparatus 100 is provided with a refrigerant circuit 106, an injection flow passage 111, and a high-pressure supply passage 130. The refrigerant circuit 106 includes a low-pressure stage compressor 105, a high-pressure stage compressor 101, a heat radiator 102, an expander 103, a gas-liquid separator 108, and an evaporator 104. The expander 103 and the low-pressure stage compressor 105 are coupled by a power-recovery shaft 107. The refrigeration cycle apparatus 100 is further provided with a flow passage-switching mechanism that selectively connects one of the evaporator 104 and the high-pressure supply passage 130 to the low-pressure stage compressor 105. The flow passage-switching mechanism, for example, is constituted by an on-off valve 131 and a check valve 132.

Abstract: An embodiment of method used to control operation of a screw compressor of a refrigeration system may include receiving status signals regarding operation of the screw compressor of the refrigeration system. The method may further include determining an operating point of the screw compressor based upon the received status signals, and selecting a torque profile for the screw compressor based upon the operating point. The method may also include driving the screw compressor per the selected torque profile. Refrigeration systems and compressor systems suitable for implementing the method are also presented.

Abstract: An operating method in a heat pump hot water supply system of an indirect heating method by which an average COP during a water heating period can be improved and a risk of running out of hot water can be prevented from increasing. For a heat pump hot water supply system of the indirect heating method, a change in heat transfer efficiency of a second heat exchanger is estimated by using either or both of a tank water temperature and a temperature of a second refrigerant flowing through a water circuit. When the heat transfer efficiency is determined to be high, an operation switching unit raises an output of a heat source device. When the heat transfer efficiency is determined to be low, the operation switching unit lowers the output of the heat source device.

Abstract: This description relates to a heat pump and a method of using the heat pump. The heat pump includes a hydraulic compressor that compresses a heat medium, an oil separation and recovery device that separates oil from the heat medium discharged from the compressor and returns the separated oil to the compressor, a condenser that liquefies the heat medium compressed in the compressor, a decompression device that decompresses the heat medium liquefied in the condenser, and an evaporator that causes the heat medium to absorb heat. The aforementioned devices are connected in series and the heat medium is circulated in those devices. The heat medium can be compressed at a compression ratio, at which a discharge temperature from the compressor becomes 150 to 200° C. An intake temperature control unit which can control the temperature of the heat medium taken into the compressor is on the intake side of the compressor.

Abstract: A refrigerated air dryer includes a three-path heat exchanger 18 having an air path 18a, a refrigerant path 18b, and a fluid path 18c. The three flow paths exchange heat within a single unit to provide a compact heat exchanger with improved thermal performance at a lower production cost.

Abstract: A device executing a start-up control method for an electric scroll compressor has a thermistor (18) and a pressure sensor (20) which, prior to the start-up of the scroll compression unit, detect temperature and pressure of a suction refrigerant introduced into the compression unit (2), and a controller (10) for controlling driving of a motor (4) of the compression unit (2) at the start-up of the compressor. The controller (10) determines at the start-up of the compressor whether or not a liquid refrigerant exists in the compression unit (2) on the basis of the detected temperature and pressure; selects either a normal start-up mode or a liquid-discharge mode in which the rotational speed of the motor (4) is regulated to be lower than in the normal start-up mode, according to the determination result; and controls the start-up of the compression unit (2) through the motor (4) according to the selected mode.

Abstract: A drive system for a compressor of a chiller system includes a variable speed drive. The variable speed drive receives an input AC power at a fixed input AC voltage and a fixed input frequency, and provides an output AC power at a variable voltage and variable frequency. The variable speed drive includes a converter connected to an AC power source. The converter is arranged to convert the input AC voltage to a DC voltage. A DC link is connected to the converter and configured to filter and store the DC voltage from the converter. An inverter is connected to the DC link. A motor is connectable to the compressor for powering the compressor. A controller is arranged to control switching in the converter and the inverter. The controller is arranged to apply randomized pulse width modulation to vary the switching frequency of transistors in the converter and the inverter at each switching cycle. The motor may be a permanent magnet synchronous motor.

Abstract: A turbo chiller equipped with a high-efficiency two-stage turbo compressor is provided. In a turbo chiller including a control unit for controlling the degrees of opening of first inlet guide vanes of a first impeller and second inlet guide vanes of a second impeller, the control unit has a slave mode in which the second inlet guide vanes are operated so as to be dependent on the first inlet guide vanes in a slave-mode priority region, and an independent mode in which the degree of opening of the second inlet guide vanes is increased independently of the first inlet guide vanes in an independent-mode priority region.

Abstract: Embodiments of apparatus, transport refrigeration units, and methods for operating the same can control cooling capacity for a refrigerant vapor compression system. Embodiments can provide use discharge pressure control for modulating cooling capacity for a refrigerant vapor compression system. In one embodiment, discharge pressure control can reduce the cooling capacity without increasing the compressor pressure ratio or discharge temperature. In one embodiment, discharge pressure control can reduce the cooling capacity independently of system superheat. In one embodiment, discharge pressure control can control a compressor discharge temperature; for example, to remain below a threshold temperature.

Abstract: A cooling system of a battery which efficiently cools a high voltage battery which is mounted in an electric vehicle or a hybrid vehicle so as to maintain battery performance by using a refrigeration cycle of an air-conditioning system, which is provided with an electric compressor, outside heat exchanger, inside heat exchanger, and a control device. A refrigerant path of the air-conditioning system for running refrigerant is provided with a branch path having a heat exchanger which bypasses the inside heat exchanger, a medium path connected to the heat exchanger runs another refrigerant for cooling the battery, control valves are provided which adjust the amounts of the refrigerant which flows to the refrigerant path and the branch path, and, when the control valves run the refrigerant to both the refrigerant path and the branch path, the control device increases the speed of the electric compressor.

Abstract: To provide an air-conditioning apparatus capable of achieving energy saving. In an air-conditioning apparatus, a first housing (an outdoor unit) that accommodates a compressor and a heat source side heat exchanger; a second housing (a heat medium relay unit) that accommodates a heat exchanger related to heat medium, an expansion device, and a pump; a third housing (a heat medium regulating unit) that accommodates a first heat medium flow switching device, a second heat medium flow switching device, and a heat medium flow control device; and a fourth housing (indoor unit) that accommodates a use side heat exchanger have separately different casings.

Abstract: A refrigerant cycle device for a vehicle includes a compressor which compresses and discharges refrigerant, a discharge capacity control portion which controls a discharge capacity of the compressor. The refrigerant cycle device further includes a noise determination portion which determines whether an audible noise other than a refrigerant passing noise is in a low noise state, and/or a load determination portion which determines whether an air-conditioning thermal load is in a high load state. The discharge capacity control portion performs a gradual activation control in which the discharge capacity of the compressor is set to be lower than that determined in a normal control, when the noise determination portion determines that the audible noise is in the low noise state, and/or when the load determination portion determines that the air-conditioning thermal load is in the high load state, at an activation time of the compressor.

Abstract: An air conditioning system. The system includes apparatus for circulating a refrigerant in a path, further having apparatus for compressing the refrigerant and generating heat in the refrigerant. The system further includes apparatus for providing a driving force to the apparatus for compressing in response to the generated heat.

Abstract: A heat pump system includes a heat source unit, a usage-side unit, and a usage-side controller. The heat source unit has a heat source-side compressor for compressing a heat source-side refrigerant, and a heat source-side heat exchanger capable of functioning as an evaporator of the heat source-side refrigerant. The usage-side unit is connected to the heat source unit and has a capacity-variable-type usage-side compressor for compressing a usage-side refrigerant, a usage-side heat exchanger capable of functioning as a radiator of the heat source-side refrigerant and functioning as an evaporator of the usage-side refrigerant, and a refrigerant-water heat exchanger capable of functioning as a radiator of the usage-side refrigerant and heating an aqueous medium. The usage-side controller performs usage-side capacity variation control for incrementally varying the operating capacity of the usage-side compressor during a usual operation.

Abstract: A system and method of operating a vehicle air conditioning system having an engine driven, fixed capacity refrigerant compressor and a compressor clutch is disclosed. The method may comprises setting a preliminary evaporator air temperature target; charging a cold storage apparatus in the vehicle air conditioning system; determining if the cold storage apparatus has reached a predetermined threshold; if the cold storage apparatus has reached a predetermined threshold, determining a new evaporator air temperature target by: determining a maximum allowable dewpoint evaporator air temperature for maintaining a passenger compartment humidity below a predetermined value; determining a maximum allowable mode evaporator air temperature based on a mode to which the vehicle air conditioning system is set; and setting the evaporator air temperature target to the lower of the dewpoint evaporator air temperature and the mode evaporator air temperature.

Abstract: A container refrigeration apparatus includes: a refrigerant circuit which performs a refrigeration cycle, and includes a main circuit sequentially connecting a compressor, a condenser, a main expansion valve and an evaporator, and a hot gas bypass circuit through which a refrigerant compressed in the compressor bypasses the condenser and the main expansion valve to flow into the evaporator; and a compressor control section which controls operating speed of rotation of the compressor during heating operation for heating inside of a container by the evaporator while returning the compressed refrigerant from the compressor to the compressor through the hot gas bypass circuit and the evaporator so that a temperature inside the container reaches a target temperature.

Abstract: A space-saving, high-density modular data pod system and an energy-efficient cooling system for cooling electronic equipment and method of cooling are disclosed. The cooling system includes a free-cooling system cooling a first fluid in thermal communication with the electronic equipment using atmospheric air and a mechanical sub-cooling system coupled to the free-cooling system. The mechanical system cools a second fluid flowing in the free-cooling system as a function of an amount by which the free-cooling system has exceeded its maximum cooling capacity. The method of cooling includes using a first fluid, enabling heat transfer from the first fluid to a second fluid that has been cooled using atmospheric air, and mechanically cooling the second fluid to the extent that free cooling the first fluid is insufficient to cool the first fluid. The cooling system operates by the wet bulb temperature exceeding a first predetermined wet bulb temperature.

Abstract: A container refrigeration system includes a refrigerant circuit configured to perform a refrigeration cycle and including a main circuit in which a compressor, a condenser, an expansion valve, and an evaporator are connected together in this order, and a hot gas bypass circuit in which compressed refrigerant of the compressor is supplied to the evaporator by bypassing the condenser and the expansion valve; and a compressor control section configured to, in a defrosting operation in which the compressed refrigerant of the compressor returns to the compressor through the hot gas bypass circuit and the evaporator and the evaporator is defrosted, control an operating speed of the compressor such that a pressure of the compressed refrigerant of the compressor reaches a target value.

Abstract: A heat source unit has a capacity-variable heat source-side compressor and a heat source-side heat exchanger which functions as a radiator of refrigerant. Usage units are connected to the heat source unit and have usage-side heat exchangers, respectively, which function as evaporators of refrigerant and cool an aqueous medium. An operating capacity controller controls the capacity of the heat source-side compressor so that evaporation temperature of refrigerant of each of the usage-side heat exchangers reaches a first target evaporation temperature. A decision unit calculates second target evaporation temperatures at which outlet temperatures of the aqueous medium in the usage-side heat exchangers of the respective operating usage units reach predetermined set temperatures, and decides a minimum value of the second target evaporation temperatures as the first target evaporation temperature.

Abstract: A centrifuge including: a rotor configured to be driven by a motor and to hold a sample, a centrifuge inverter, a chamber accommodating the rotor, a temperature sensor configured to detect the temperature of the chamber, a cooling machine configured to cool the chamber and including a compressor, a compressor inverter, a compressor motor configured to be controlled in a variable speed and a control device, wherein the control device carries out a feedback control of the compressor motor based on a preset temperature and a detected temperature of the temperature sensor when the rotation number of the compressor motor is larger than a predetermined rotation number, and the control device carries out an intermittent control for turning ON-OFF the cooling function of the compressor when the rotation number of the compressor motor is smaller than a predetermined rotation number.

Abstract: A drive system for a compressor of a chiller system includes a variable speed drive. The variable speed drive is arranged to receive an input AC power at a fixed AC input voltage and fixed input frequency and provide an output AC power at a variable voltage and variable frequency. The variable speed drive includes a converter connected to an AC power source providing the input AC voltage. The converter is arranged to convert the input AC voltage to a DC voltage. A DC link is connected to the converter. The DC link is arranged to filter and store the DC voltage from the converter. A first inverter and a second inverter are each connected to the DC link. A motor includes stator windings connected between the first inverter and the second inverter to power the motor by the output AC power from the first inverter and the second inverter. The motor is connectable to a compressor of the chiller system to power the compressor. The motor may be a permanent magnet synchronous motor.

Abstract: A refrigerant cycle device includes a first refrigerant passage for guiding refrigerant from a refrigerant radiator to an inlet side of an outdoor heat exchanger, a first throttle part capable of varying an opening area of the first refrigerant passage, a second refrigerant passage for guiding the refrigerant from the outdoor heat exchanger to a compressor-suction side, a first opening/closing part for opening/closing the second refrigerant passage, a third refrigerant passage for guiding the refrigerant from the outdoor heat exchanger to the compressor-suction side via an evaporator, a second throttle part capable of varying an opening area of the third refrigerant passage, a bypass passage for guiding the refrigerant flowing between the refrigerant radiator and the first throttle part to a position between the outdoor heat exchanger and the second throttle part in the third refrigerant passage, and a second opening/closing part for opening/closing the bypass passage.

Abstract: An air-conditioning apparatus for a vehicle cabin has an air-conditioning case defining a plurality of air intake modes. The plurality of air intake modes includes an ambient air intake mode, and a double-layered air intake mode. The double-layered air intake mode supplies ambient air to a front side of the vehicle cabin via a front air passage, and supplies a recirculation air from the vehicle cabin to the rear side of the vehicle cabin via a rear air passage. The controller controls the air-conditioning case to switch the air intake mode from the double-layered air intake mode to the ambient air intake mode, when an evaporator temperature falls below a first threshold value.

Abstract: An air-conditioning apparatus includes an outdoor air temperature sensor detecting an outdoor temperature; a compressor temperature sensor detecting a temperature of an outer wall of a compressor; a liquid-level and concentration detection sensor detecting a liquid surface level in the compressor and a concentration of a lubricant oil in a liquid in the compressor; an electric heater heating the compressor; and a controller that carries out preheating to the compressor by driving the electric heater when a detection value of the outdoor air temperature sensor is higher than or equal to a detection value of the compressor temperature sensor and, further, when the liquid surface level detected by the liquid-level and concentration detection sensor is higher than or equal to a predetermined level and the concentration of the lubricant oil in the liquid is lower than a preset minimum required concentration.

Abstract: A controller for a drive motor for a scraper of a frozen product dispenser operates the drive motor to rotate the scraper at selected ones of a plurality of different speeds within a freeze barrel of the dispenser, in accordance with the values of sensed operating parameters of the dispenser. The arrangement provides for rotation of the scraper at speeds appropriate for, but no greater than required for, the then existent operating condition of the dispenser.

Abstract: A cascade heat pump system is configured with variable-speed compressors which allow operation at a high system coefficient of performance for a given thermal load. An electronic control module may be utilized to dynamically vary the speed of the compressors to achieve maximum energy efficiency. Variable-speed fans or blowers may also be used.

Abstract: A beverage dispensing apparatus is characterized by a beverage dispenser and a refrigeration system for chilling beverage to be dispensed by the beverage dispenser. The refrigeration system has a compressor coupled to an evaporator for chilling the beverage, and a controller determines the amount of chilling that must be provided by the refrigeration system to chill the beverage and adjusts cut-in and cut-out beverage temperature set-points for the compressor accordingly. Advantageously, the cut-in and cut-out set-points are adjusted to beverage temperature values such that the chilling capacity of the refrigeration system is made to closely match to the amount of chilling required by the beverage, and also such that on/off cycles of the refrigeration system are decreased.

Abstract: A climate control system includes a control head having a warmer/cooler temperature control for providing relative thermal comfort. A thermal comfort rating (TCR) corresponding to a range of passenger cabin temperatures is determined based upon a comfort level selection by an occupant using the control head. A control strategy employs look-up tables corresponding to the TCR to determine the speed of an electric compressor and the position of a temperature control blend door. The strategy provides for a relatively fast ramp down to a minimum compressor speed to improve fuel economy while maintaining a relative level of thermal comfort.

Abstract: An air conditioner is provided. A control unit of an outdoor unit of the air conditioner is divided into a plurality of blocks according to a set of rules. Then, the blocks are mounted on different substrates. Therefore, it is possible to simplify wiring, facilitating the interconnection of the blocks and enable the control unit to be managed in units of the blocks. In addition, it is possible to improve user convenience.

Abstract: Provided is a temperature control system, including a closed refrigerant circuit having an evaporator unit configured for absorbing heat via the refrigerant, thereby evaporating it, a compressor unit configured for increasing the pressure and temperature of refrigerant within the circuit, and a condenser unit configured for rejecting heat from the refrigerant, thereby liquefying it. The compressor unit includes a mechanical compressor configured for increasing the pressure of the refrigerant and a thermal collector configured for utilizing an external heat source to increase the temperature of the refrigerant.