There is disclosed a method of controlling an air-cargo transport refrigeration unit to regulate a compressor speed and a condenser fan speed. There is also disclosed a method of controlling an air-cargo transport refrigeration unit based on determining an in-flight condition of the refrigeration unit.

A method and system for improving energy efficiency of a refrigeration system include system components such as a condenser, one or more expansion valves, an evaporator, one or more compressors, and a system controller electrically coupled to the one or more of the system components, according to one embodiment. The system controller is configured to selectively actuate, directly or indirectly, the one or more expansion valves, the condenser, and/or the one or more compressors, at least partially based on temperatures and/or pressures of the system fluid at various points of the system, to control a temperature of a refrigerated area.

An information processing apparatus, based on a data set including a combination of information indicating a situation, information on the comfort of a user, and information on power consumption when an air conditioner has been operated, executes a process of determining an operation setting according to a situation when the air conditioner is operated, the comfort when the air conditioner is operated, and a condition related to the power consumption when the air conditioner is operated.

A chiller system is provided and includes a compressor, a variable frequency drive (VFD) to drive the compressor at variable frequencies and a chiller controller to ascertain a chiller condition and to command the VFD to drive the compressor at one of the variable frequencies based on the chiller condition at a first sampling rate. The VFD is configured to drive the compressor at the one of the variable frequencies responsive to being commanded by the chiller controller, to ascertain the chiller condition at a second sampling rate, which is substantially higher than the first sampling rate, and to alert the chiller controller accordingly.

A vapor compression system includes a compressor, a first heat exchanger, an expansion valve and a second heat exchanger arranged serial refrigerant flow path; a first fan configured to direct air over the first heat exchanger; a controller coupled to the first fan and the compressor, the controller configured to: set a compressor discharge superheat limit; determine a compressor discharge superheat; compare the compressor discharge superheat to the compressor discharge superheat limit; and when the compressor discharge superheat is less than the compressor discharge superheat limit, the controller reducing at least one of a compressor speed and a first fan speed.

An air conditioning system includes a storage medium and an air conditioning system, for a three-pipe air conditioning system, the three-pipe air conditioning system includes a compressor, an outdoor heat exchanger, an indoor heat exchanger, a gas-liquid separator, a first pipeline, a second pipeline and a third pipeline; the oil return control method comprises the following steps: controlling the compressor to operate at a first frequency in a refrigerating mode; judging whether the operation duration of the refrigerating mode reaches a first preset time or not; if so, the air conditioning system enters an oil return state, and the compressor, the third pipeline, the second pipeline and the gas-liquid separator are controlled to be communicated in sequence to form a refrigerant circulation loop.

A refrigeration cycle apparatus includes a compressor, a condenser, a first subcooling device that subcools a refrigerant by exchanging heat with the air, a second subcooling device that performs a heat exchange between refrigerant streams that have been branched by a branch pipe, thereby subcooling one of the refrigerant streams, a flow control device that adjusts a flow rate of the second stream of the refrigerant and passes this refrigerant through the second subcooling device, a bypass path that allows the refrigerant passing through the flow control device and the second subcooling device to flow therethrough, an expansion valve, an evaporator, and a controller configured to control an amount of heat exchanged in the first subcooling device and an amount of heat exchanged in the second subcooling device based on a temperature of the air.

A refrigeration system includes at least one compressor, a condenser, one or more sensors, and a controller. The one or more sensors are operable to sense data associated with the refrigeration system. The controller is operable to receive operating data associated a first control variable and a second control variable, the operating data received from the one or more sensors. The controller is further operable to determine, based on the operating data, that a control objective is not met, and operate the refrigeration system according to a configuration selected to cause the control objective to be met in response to determining that the control objective is not being met, wherein operating the refrigeration system according to the configuration selected to cause the control objective to be met comprises overriding control of the second control variable until the control objective is met.

A heat pump system includes a refrigerant circuit, at least one compressor, an evaporator, and a controller programmed to defrost the evaporator in a defrost mode, wherein in the defrost mode the controller is programmed to monitor the evaporator to detect frost creation thereon, and reduce the speed of the at least one compressor and/or reduce the number of some, but not all operating compressors of the at least one compressor, if frost creation is detected on the evaporator. In some embodiments, the controller is programmed to defrost the evaporator in a second defrost mode. In the second defrost mode the controller is programmed to monitor the evaporator to detect frost creation thereon, turn off the at least one compressor when frost is detected on the evaporator, and operate a fan to force ambient air over the evaporator to defrost the evaporator.

Methods and systems for providing control of a heat pump of a motor vehicle are presented. In one operating mode, speed of a heat pump compressor is controlled responsive to an outlet pressure of the heat pump compressor. In a second operating mode, speed of the heat pump compressor is controlled responsive to a pressure ratio between an inlet and an outlet of the heat pump compressor.