Abstract: A compressor inlet pressure estimation apparatus for a refrigeration cycle system is disclosed. An electronic control unit 14 uses Tefin_lag(N) as an actual corrected temperature Tefin_AD(N) during a period Tp1 included in the timing t1 to t2. During a period Tp2 included in the timing t1 to t2, Tefin_fwd(N) is used as the actual corrected temperature Tefin_AD(N). Thus, a highly accurate corrected temperature Tefin_AD(N) can be determined over the on period (t1 to t2) of a compressor 2. In addition, Tefin_fwd(N) is used as the actual corrected temperature Tefin_AD(N) during the off period (t2 to 3) of the compressor 2. As a result, a highly accurate corrected temperature Tefin_AD(N) can be determined over the whole period including the on and off periods of the compressor 2. In this way, a highly accurate estimated value Ps_es(N) of the refrigerant inlet pressure of the compressor 2 can be determined.

Abstract: An output-side swing arm is adapted to be swung about a swing axis thereof when the output-side swing arm is urged by a corresponding part of an input-side swing arm, which is driven by a force transmitted from an input shaft. An adjusting mechanism adjusts an amount of swing of the output-side swing arm by changing a location of a point of action of the input-side swing arm relative to the output-side swing arm in a radial direction of the swing axis of the input-side swing arm.

Abstract: An air conditioning apparatus includes a refrigerant circuit, a refrigerant heating unit and a stop signal controller. The refrigerant circuit includes a compressor, an indoor heat exchanger, a pressure reducing mechanism, and an outdoor heat exchanger. The refrigerant heating unit heats refrigerant flowing through the refrigerant circuit. The stop signal controller, in a case of causing the compressor to stop at a time when the compressor and the refrigerant heating unit are both operating, executes first stop control in which a stop signal is issued in order to stop the refrigerant heating unit, and then a stop signal is issued in order to stop the compressor after elapse of a first amount of time. A method of controlling an air conditioning apparatus having the refrigerant circuit and the refrigerant heating unit includes executing the first stop control.

Abstract: To provide a multistage compressor including an injection circuit, which can continue high-efficiency and high-capacity operations even if the injection circuit is turned on/off in accordance with operating conditions. A multistage compressor includes a high stage side compressing mechanism suctioning the intermediate pressure refrigerant gas compressed with a low stage side compressing mechanism to perform two-stage compression, and an injection circuit for injecting an intermediate pressure refrigerant into the intermediate pressure refrigerant gas suctioned to the high stage side compressing mechanism, the high stage side compressing mechanism including a capacity control mechanism for bypassing a refrigerant gas that is being compressed to a suction side, the injection circuit including an on/off mechanism for performing on/off control of refrigerant injection, and the capacity control mechanism and the on/off mechanism being operated in conjunction with each other.

Abstract: An oil level detecting device for a compressor and an air conditioning system having the same are provided. The oil level detecting device may be provided in a compressor including a compression device that introduces and compresses a working fluid, a driving device mechanically connected to the compression device that operates the compression device, and a case that accommodates the compression device and the driving device thereinside and having an oil storage space that stores oil at a lower portion thereof. The oil level detecting device may include a detector including a supporting portion configured to be attached to the case and a detecting portion that protrudes inside the case. At least one property of the detecting portion may vary according to an oil level inside the case. The oil level detecting device may also include a signal processor including an electronic element having at least one reference property.

Abstract: A capacity control system for a variable capacity compressor includes target suction pressure setting means for setting, based on external information input from external information detection means, a target suction pressure for controlling the pressure in a suction pressure region as a control target, suction pressure estimation means for estimating, based on the external information, a pressure that is estimated to prevail in the suction pressure region if the variable capacity compressor is operated with a maximum discharge capacity, and discharge capacity determination means for determining, based on the suction pressure estimated by the suction pressure estimation means and the target suction pressure set by the target suction pressure setting means, whether the variable capacity compressor is operating with the maximum discharge capacity or with a controlled discharge capacity.

Abstract: An HVAC system and method for configuring a controller to control a compressor including a detection system provided to determine a type of compressor. The detection system includes a processor; and a load sensing circuit connected between the processor and a controller. The controller has a plurality of output connections connectable to a compressor. The load sensing circuit senses whether a load is present on each output connection of the plurality of output connections and provides a load signal to the processor indicating whether a load is present on each output connection. The load signals are processed with the processor to determine the type of compressor is present. The controller is configured to control the compressor in response to the determined type of compressor.

Abstract: A system and a method for controlling an operation of a vapor compression system are disclosed, such that a performance of the system measured in accordance with a metric of the performance is optimized. A control signal is modified with a modification signal including a perturbation signal having a first frequency, wherein the control signal controls at least one component of the vapor compression system. A metric signal representing a perturbation in the performance of the system caused by the modification signal is determined, wherein the metric signal has a second frequency substantially equal to the first frequency. The control signal is adjusted based on a function of a phase between the perturbation signal and the metric signal, such that the performance is optimized.

Abstract: An air conditioner according to an embodiment of the invention includes a refrigerator cycle unit having a variable speed compressor, an outdoor heat exchanger, a decompression device, an indoor heat exchanger, and an accumulator sequentially connected to one another, a bypass pipe that connects the discharge side of the compressor and an outlet of the accumulator and has a two-way valve in the middle thereof, a discharge temperature sensor that detects the temperature of the compressor, and a controller that opens or closes the two-way valve, and limits the number of rotations of the compressor to a predetermined value or less, on the basis of the temperature detected by the discharge temperature sensor when the compressor starts.

Abstract: A refrigerating apparatus having a plurality of compressors includes an injection circuit (40) which includes a first injection pipe (37) branched from a first refrigerant pipe (32) of a refrigerant circuit (10) and branch injection pipes (37a, 37b, 37c) branched from the first injection pipe (37), a subcooling pressure-reducing valve (29) provided to the first injection pipe (37), and flow rate adjusting valves (30a, 30b, 30c) provided to the branch injection pipes (37a, 37b, 37c), respectively, thereby providing an appropriate refrigerant injection to each of the compressors.

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: Both of maintenance of cooling performance of low-temperature showcases and enhancement of energy saving performance of a refrigerating machine are enabled. A cooling system 1 is constructed to have a refrigeration circuit 2 in which low-temperature showcases 7 as plural load facilities are connected to a rack system refrigerating machine 3 in parallel through refrigerant pipes 5a and 5b, a main controller 4 for generating and outputting control data of compressors 9 constructing the rack system refrigerating machine 3 on the basis of the cooling state of the low-temperature showcases 7, and a compressor controller 6 which is constructed to acquire control setting required for capacity control of the compressors 9 as main elements of the rack system refrigerating machine 3, receives control data from the main controller 4 and controls the compressors 9 on the basis of the control setting and the control data.

Abstract: In a refrigeration unit including a variable performance compressor driven by an inverter motor, a sensor is configured to detect a physical amount corresponding to a refrigerant pressure on the high-pressure side of a refrigerant circuit. A measured value of the physical amount is compared with a first reference value corresponding to a first predetermined pressure of the refrigerant and a second reference value corresponding to a second predetermined pressure lower than the first predetermined pressure. A protective operation can start if the comparison result indicates that an actual refrigerant pressure is higher than the first predetermined pressure. The performance of the compressor can be gradually lowered if the comparison result indicates that an actual refrigerant pressure is between the first predetermined pressure and the second predetermined pressure.

Abstract: A refrigerant system adjusts, in a coordinated prioritized manner, the variable capacities of a compressor, evaporator fan and a condenser fan to minimize the system's overall power consumption while maintaining a comfort zone within a target comfort range. The target comfort range is defined by desired temperature and humidity limits. When the comfort zone is within the target comfort range, the system periodically attempts to reduce the compressor capacity. If the attempt succeeds, the evaporator fan capacity is then minimized. The condenser fan capacity can also be minimized provided the refrigerant system can maintain at least a minimum saturated suction temperature of the refrigerant flowing from the condenser to the compressor.

Abstract: A vehicle air conditioning system includes a compressor, a condenser, an evaporator, a humidity sensor and a controller. The compressor is configured to compress refrigerant and the condenser is fluidly coupled to the compressor to receive the refrigerant from the compressor. The evaporator is fluidly coupled to the condenser to receive the refrigerant from the condenser and fluidly coupled to the compressor to supply the refrigerant to the compressor. The humidity sensor is positioned proximate the evaporator to detect moisture density of air passing through the evaporator towards a vehicle passenger compartment. The controller is operatively coupled to the humidity sensor and the compressor to cycle the compressor on and off to maintain the moisture density in the air being cooled by the evaporator and sensed by the humidity sensor below a predetermined moisture density threshold.

Abstract: In an electric refrigeration appliance having at least one refrigeration compartment, a refrigerating arrangement having an evaporator, and a control device that controls the refrigeration compartment temperature and that has a temperature sensor; the temperature sensor is located away from the evaporator and in a portion of a refrigeration compartment volume selected with the exclusion of a first top portion of the refrigeration compartment having a volume equal to roughly 8-10% of the total internal volume of the refrigeration compartment, and with the exclusion of a second front portion of a depth equal to at least 10% of the total inside depth of the refrigeration compartment.

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 high pressure side pressure in a refrigerant circuit while reducing noises of an operation of a blower in a refrigerating apparatus which obtains a critical pressure on a high pressure side. The refrigerating apparatus in which the refrigerant circuit is constituted of a compressor, a gas cooler, reducing means and an evaporator to obtain a supercritical pressure on the high pressure side comprises a blower which air-cools the gas cooler and a control device which controls this blower. This control device controls a revolution speed of the blower based on an outdoor temperature and an evaporation temperature of a refrigerant in the evaporator.

Abstract: A reciprocating piston compressor for use in a refrigerant compression circuit comprises first and second intake manifolds, first and second reciprocating piston compression units, an outlet manifold and a first pulsing valve. The intake manifolds segregate inlet flow into the compressor. The first and second reciprocating piston compression units receive flow from the first and second intake manifolds, respectively. The outlet manifold collects and distributes compressed refrigerant from the compression units. The first pulsing valve is mounted externally of the first intake manifold to regulate refrigerant flow into the first intake manifold. In another embodiment, a second valve is mounted externally of the second intake manifold to regulate flow into the second intake manifold, and the first and second valves are operated by a controller. The controller activates the first valve with variable width pulses having intervals less than an operating inertia of the refrigerant compression circuit.

Abstract: A vehicle air conditioning system includes a controller that initially controls operation of a compressor to switch between inactive and active states in response to detecting that an operating condition is equal to or surpasses a first operation threshold. The controller determines a first time delay occurring between initiating the switch from one of the inactive and active states to the other of the compressor, and an actual change in the operating condition. The controller subsequently defines a first limit that is offset from the first operation threshold such that the controller controls the operation of the compressor to subsequently switch from the one of inactive and active states to the other in response to detecting that the operating condition is equal to or surpasses the first limit.

Abstract: A vapor compression system that circulates a fluid through a closed loop interconnecting a compressor, a first heat exchanger, a flow-restricting expansion device, and a second heat exchanger. The system further includes a vessel in a first fluid communication and a selective second fluid communication with the loop between the compressor and the first heat exchanger with each of the first and second fluid communication configured to receive fluid from the loop. The vessel is in a third fluid communication with the first heat exchanger configured to provide fluid to the first heat exchanger. In response to a predetermined ambient temperature surrounding the system, the second fluid communication is selectively opened to provide an increased fluid flow from the vessel to the first heat exchanger.

Abstract: A control system controls a vehicle air-conditioning system including a cooling circuit having a compressor with a refrigerant that is supplemented with a compressor lubricant. The control system includes a control unit which controls the drive torque used for starting up the compressor. The control unit reduces the drive torque as a function of a determined time parameter that represents an elapsed compressor stoppage time (?T).

Abstract: An object is to sequentially calculate planned COPs.

Abstract: A compressor and an air-conditioner having the same are disclosed. A compressor application voltage is detected, and the air-conditioner is operated in a pre-set operation mode according to the detection result, or the air-conditioner is operated in a pre-set operation mode in a certain time domain, thus continuously operate the compressor. Or, a compressor temperature or an ambient temperature is detected to operate the air-conditioner in a pre-set operation mode or operate the air-conditioner in a pre-set operation mode within a certain time domain, thus continuously operate the compressor. Accordingly, the compressor can be operated in a particular operation mode within a certain time slot regardless of an ambient temperature, whereby an excessive cooling operation cannot be performed at night to thus provide an agreeable cooling operation and reduce noise.

Abstract: A semi-frozen product dispenser (10 or 200) is provided for at least partially freezing and dispensing a product. The product dispenser may include at least one freezing barrel (20-1) defining a freezing chamber (C1) configured to receive the product. A refrigeration system (60 or 260) is provided for at least partially freezing product in the freezing chamber (C1). A fluid heating system (80 or 280) is also provided to remove heat from the refrigeration system (60 or 260) and use it in an auxiliary system, such as a water pre-heating system. The fluid heating system (80 or 280) may include a fluid heat exchanger (102) disposed in a high pressure refrigerant line (67 or 267), a fluid tank (82 or 282), and a fluid pump (96). Fluid may be continuously circulated through the fluid heat exchanger (102 or 302) when the refrigeration system is operated, thereby to continuously provide refrigerant cooling and fluid warming.

Abstract: A vehicle air-conditioning apparatus, including: a refrigerant circulation channel that flows a refrigerant, the refrigerant circulation channel provided in a refrigeration cycle system including, as connected in a cyclic pattern, a compressor for the refrigerant, an outdoor heat-exchanger exchanging heat between the refrigerant and an outdoor air, an expansion valve reducing pressure of the refrigerant, and an air-conditioning heat-exchange circuit exchanging heat between the refrigerant and air to be introduced into a vehicle interior; and an equipment heat-exchange circuit connected in parallel to the circuit and exchanging heat between the refrigerant and in-vehicle equipment. The circuit includes a cooling heat-transfer medium circulation channel that circulates a heat-transfer medium for cooling.

Abstract: An air conditioner performs startup control in which compressor capacity is reduced as measured indoor temperature approaches a set temperature. A desired time of day is set directly or indirectly. A startup control apparatus of the air conditioner measures an inflection point occurrence time from when the air conditioner starts operation until when measured indoor temperature exhibits an inflection point. Alternatively, the startup control apparatus measures a control parameter lowering arrival time from when the air conditioner starts operation until when a control parameter transmitted to the compressor decreases to a prescribed value. A scheduled operation start time of the air conditioner is set as a time of day that is the desired time of day set moved forward by the inflection point occurrence time or the control parameter lowering arrival time. Operation of the air conditioner is started when the scheduled operation start time arrives.

Abstract: A compressor for compressing a refrigerant containing a substance having a double bond, a condenser for condensing the refrigerant by heat exchange, expanding means for decompressing the condensed refrigerant, and an evaporator for evaporating the decompressed refrigerant by heat exchange are connected by piping so as to configure a refrigerant circuit through which the refrigerant is circulated, and control means is provided for controlling an operation of the refrigerant circuit so that a pressure of the refrigerant in the refrigerant circuit becomes less than a critical pressure of the substance having the double bond.

Abstract: A brushless direct current motor, includes a rotor which comprises a permanent magnet, a stator which comprises coils associated with a plurality of phases which form an electrical field for generating a torque by interaction with a magnetic field which is generated by the permanent magnet, and a load prevention part which is disposed inside the stator to electrically connect and disconnect the coils of the plurality of phases according to a temperature variation.

Abstract: A refrigerant system adapted to reduce refrigerant migration therein includes a compressor and a controller. The compressor has a motor with motor windings. The motor windings are responsive to control signals to selectively generate heat in a manner that does not turn the motor. The controller selectively energizes the motor windings to generate heat based on at least one of a monitored temperature or pressure to warm the compressor.

Abstract: An automotive vehicle includes an air conditioning system configured to selectively cool a cabin of the vehicle and at least one electrical component of the vehicle. The vehicle also includes one or more controllers configured to determine whether the air conditioning system is operating to cool the at least one electrical component, to determine whether cabin cooling is requested, and to enable the air conditioning system to cool the cabin if the air conditioning system is operating to cool the at least one electrical component and if cabin cooling is requested.

Abstract: A refrigerant cycle is provided with a multi-port compressor or compressor stages connected in series, and multiple condensers. A single evaporator communicates with the plurality of condensers. At least one of the plurality of condensers receives fully compressed refrigerant while the other condensers receive refrigerant at intermediate pressure. A control can optionally direct refrigerant to the condensers to achieve desired system heat rejection characteristics and operating conditions. One or multiple reheat coils may be associated with the evaporator and are arranged either in series or in parallel to provide a desired dehumidification function and reheat stages. One or several of the intermediate pressure condensers may be utilized for the reheat function as well.

Abstract: A single medium voltage starter box is mounted on a chiller unit with the other components of the chiller system. The starter box can be positioned on the chiller system unit to permit the starter box to be close coupled to the motor, and specifically to the main motor lead exit hub without the need for any power conduit connections between the starter box and the motor. In addition, the starter box also does not require any control interface and receives controls from a control panel. A short conduit connection between the control panel and the starter box is used to provide the necessary connections between the control panel and the starter box.

Abstract: An air-conditioning control device for a vehicle includes an air-conditioner, an estimating portion, and a controller. The air-conditioner includes a compressor driven by an engine of the vehicle so as to compress refrigerant, and a heat storage portion having a coolness storage agent to store heat of the refrigerant. A passenger compartment of the vehicle is air-conditioned using air cooled by the heat storage portion when the compressor is stopped. The estimating portion estimates a present value of coolness amount stored in the heat storage portion based on a temperature history of the refrigerant. The controller controls the compressor based on the estimated present value of coolness amount.

Abstract: Dehumidifiers for high temperature operation and associated systems and methods are disclosed. A method in accordance with a particular embodiment includes drawing air into a dehumidifier and automatically monitoring an electric current drawn by a refrigerant compressor of the dehumidifier. The method can further include automatically stopping the compressor in response to the current meeting or exceeding a predetermined threshold value, and automatically restarting the compressor in response to the compressor meeting a predetermined condition that includes or corresponds to a target pressure difference between refrigerant pressures upstream and downstream of the compressor. The predetermined condition, in at least some embodiments, includes the passage of a period of time sufficient to allow refrigerant pressures upstream and downstream of the compressor to come within a preselected range of each other.

Abstract: The invention provides a refrigeration system with a compressing unit, and a method of controlling a refrigeration system. To facilitate a better control, the capacity of the compressing unit is controlled based on a predicted future cooling demand rather than an actually determined cooling demand. The invention further provides a system wherein a cost value for changing the cooling capacity of the system is taken into consideration.

Abstract: A humidity detecting apparatus includes a humidity sensor for detecting a relative humidity of air on an inner side of a window glass, an air temperature sensor for detecting a temperature of the air, a glass temperature sensor for detecting a temperature of the window glass, and a glass surface relative humidity calculation unit for calculating a glass surface relative humidity based on output values of the humidity sensor, the air temperature sensor and the glass temperature sensor. A heat conductive member is disposed between the glass temperature sensor and the window glass.

Abstract: A system for controlling a centrifugal gas compressor (108) in an HVAC, refrigeration or liquid chiller system (100) in which flow of gas through the compressor is automatically controlled to maintain desired parameters within predetermined ranges so as to prevent stall and surge conditions within the system. A variable geometry diffuser (119) in the compressor controls the refrigerant gas flow at the discharge of the compressor impeller wheel (201). This arrangement reduces mass flow, decrease/eliminate flow-reducing stall, and increases the operating efficiency of the compressor at partial load conditions. The variable geometry diffuser control in combination with a variable speed drive (VSD) (120) increases the efficiency of the compressor at partial system loads, and eliminates the need for pre-rotation vanes at the inlet of the centrifugal compressor.

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: A tumble dryer with at least one heat pump system has an air stream circuit (10) including at least one drum (12) for receiving laundry to be dried, at least one refrigerant circuit (14) including at least one compressor (16) with a variable rotation speed, a first heat exchanger (18) for a thermal coupling between the air stream circuit (10) and the refrigerant circuit (14), and a second heat exchanger (20) for a further thermal coupling between the air stream circuit (10) and the refrigerant circuit (14). The tumble dryer further includes a control unit (22) for controlling the rotation speed of the compressor (16) and at least one sensor for detecting at least one physical parameter (TDI, TDO; TEI, TEO; TF; Z; RH) as function of the time of the air stream, the refrigerant ad/or the laundry.

Abstract: A control methodology for dynamically adjusting the switching limits of a cycled refrigerant compressor in an air conditioning system with the objective of achieving an optimal or specified tradeoff between compressor cycling frequency and discharge air temperature variation under all operating conditions. In a first embodiment, the compressor cycling limits are controlled to maintain a virtually constant discharge air temperature variation for all operating conditions. In a second embodiment, the compressor cycling limits are controlled so that the discharge air temperature variation changes in relation to the discharge air temperature to provide a virtually constant human comfort level for the occupants. And in a third embodiment, the compressor cycling limits are controlled so that the discharge air temperature variation changes in relation to the ambient or outside air temperature to provide a virtually constant human comfort level for the occupants.

Abstract: A trailer refrigeration system comprising: an electricity generator (22); an electricity-generator engine (21) for driving the electricity generator (22); a converter (23) for converting ac electric power generated by the electricity generator (22) into dc electric power; an inverter (24, 25, 26) including inverters (24), (25), (26) each for converting dc electric power from the converter (23) into ac electric power; a refrigerant circuit (30) having an electric compressor (31) and a fan (35, 36) including fans (35), (36), the electric compressor (31), the fan (35), and the fan (36) being driven respectively by ac electric power from inverters (24), (25), (26); and a control means (40) for individually controlling the speed of rotation of the electric compressor (31), the fan (35), and the fan (36).

Abstract: A refrigeration system comprises a plurality of compressors and a plurality of condensing units comprising a first condensing unit having a first control module and at least one additional condensing unit having an additional control module. Each condensing unit has at least one compressor of the plurality of compressors. A communication link is connected to the first control module and at least one additional control module. The first control module controls the plurality of compressors based on communication with the at least one additional control module via the communication link.

Abstract: A system and method includes a compressor operable in a refrigeration circuit and including a motor, a current sensor detecting current supplied to the motor, a discharge line temperature sensor detecting discharge line temperature of the compressor, and processing circuitry receiving current data from the current sensor and discharge line temperature data from the discharge line temperature sensor and processing the current data and the discharge line temperature data to determine a capacity of the refrigeration circuit.

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

Abstract: A method for operating a heat pump (100) in low ambient air temperatures comprises periodically or temporarily halting flow of refrigerant through an evaporator (170) of the heat pump (100) and providing forced airflow across the evaporator (170) while the refrigerant flow is halted. The method enables operation of the heat pump (100) at low ambient temperatures and provides a means for de-icing the evaporator (170) when operating at low ambient temperatures. The method is particularly applicable to heat pumps having an evaporator located outdoors, such as domestic and industrial water heating systems.

Abstract: A method for operating a linear compressor including a linear drive with a stator and a rotor configured for displacement by a magnetic field of the stator against a spring force, and a compression chamber which is delimited by a displaceable piston coupled to the rotor during the operation of which an alternating current is applied to the stator in order to drive the rotor in an reciprocatingly, the method including the steps of applying, prior to operation, a direct current with a first polarity to the stator in order to displace the rotor from a rest position, measuring a first end position attained by the rotor under the action of the direct current, and controlling, during operation, the intensity of the alternating current with which the stator is excited in a manner wherein the rotor does not reach the first end position or reaches it at a reduced speed.

Abstract: A method of operating a HVAC system in a vehicle having an engine that operates in a high efficiency mode and a less efficient mode is disclosed. The method may comprise the steps of: operating a refrigerant compressor to cool a passenger compartment and charge a cold thermal storage apparatus; determining if a cold charge in the storage apparatus has exceeded a threshold; enabling compressor cycling if the cold charge in the storage apparatus has exceeded the threshold; detecting if the engine is operating in the high efficiency mode; determining an amount of HVAC loads on the engine; determining a proximity of the engine operation to a switching point from the high efficiency mode to the less efficient mode; and conducting a HVAC load shed if the HVAC load reduction allows the engine to stay below the switching point and the compressor cycling is enabled.

Abstract: A controller and method for control of a refrigeration system having a compressor rack operable at a plurality of capacities may include determining a rate of change in suction pressure for a first capacity, determining a rate of change in suction pressure associated with a second capacity, and determining which of the first capacity and the second capacity will produce the least variation between a measured suction pressure and a desired suction pressure based on the rate of change in suction pressure associated with each.

Abstract: A refrigerating apparatus for keeping an inside of a storage at a predetermined low-temperature state includes first and second refrigerant circuits including compressors, condensers, decompressors, and evaporators, connected circularly with pipings to form refrigerating cycles, the circuit having a first or second refrigerant sealed therein as a working refrigerant, a first sensor which detects a temperature of a cascade condenser constituted by integrating the evaporator of the first refrigerant circuit and the condenser of the second refrigerant circuit in a heat exchangeable manner, first and second controllers which control operation performances of the first and second compressors in a variable manner based on first and second sensor detected temperatures in order that the first and second sensor detected temperatures are first and second temperatures, respectively, and a second sensor which detects a temperature inside the storage.