An air-conditioner may include an evaporator, a compressor configured to compress refrigerant supplied to the evaporator and a clutch configured to transmit power needed to operate the compressor to the compressor or to prevent power from being supplied to the compressor, wherein the clutch prevents power from being supplied to the compressor when an actual measurement temperature of the evaporator reaches a lower limit threshold temperature selected among the lower limit threshold temperature and an upper limit threshold temperature and the lower limit threshold temperature is changeable, and the upper limit threshold temperature is relatively higher than the lower limit threshold temperature and is changeable.

A vehicular air conditioning system includes: a refrigerant circulation line provided with a compressor, an outdoor heat exchanger, an expansion valve and an indoor heat exchanger; and a control unit configured to variably control a rotation speed of the compressor depending on a refrigerant discharge pressure and a refrigerant discharge temperature on an outlet side of the compressor.

A refrigeration cycle apparatus includes: an electric compressor that compresses and discharges refrigerant; a heating heat exchanger that heats a fluid by high pressure refrigerant discharged from the electric compressor as a heat source; a decompressor that decompresses the refrigerant flowing from the heating heat exchanger; an evaporator that evaporates the refrigerant decompressed by the decompressor; and a rotational speed controller that controls a rotational speed of the electric compressor. The rotational speed controller is configured to reduce an upper limit value of the rotational speed of the electric compressor in accordance with an increase in a pressure ratio of a high-pressure side refrigerant pressure of refrigerant within a range from a discharge port of the compressor to an inlet side of the decompressor to a low-pressure side refrigerant pressure of refrigerant within a range from an outlet side of the decompressor to a suction port of the compressor.

A control method of an air conditioning system for compressor protection includes, when an air conditioner turn-on request is present, determining, by a controller, whether a compressor operating condition is satisfied from a refrigerant state of an air conditioner, when the compressor operating condition is determined as being satisfied, determining, by the controller, whether the vehicle is in a state of being unattended for a long period of time using information collected from a vehicle, when the vehicle is determined as being in a state of being unattended for a long period of time, performing, by the controller, pre-run control for operating the compressor in a predetermined minimum load condition; and when a pre-run operating time for which the compressor is operated in a minimum load condition reaches a predetermined pre-run holding time, interrupting, by the controller, the pre-run control with respect to the compressor.

Methods and systems are provided for controlling an air conditioning compressor clutch. In one example, a method includes monitoring a clutch of an air conditioning system in a vehicle when the air conditioning system is activated, and responsive to determining that the clutch is not engaged, increasing a current flow to the clutch. In this way, engagement of the compressor clutch may be dynamically maintained with a reduced usage of electrical power.

A method of controlling an electric compressor, includes aligning a position of a rotor after an electric compressor is powered on; determining whether a refrigerant is in a liquid phase or in a gas phase; preheating the refrigerant by applying power to the electric compressor according to the phase of the refrigerant; and controlling the electric compressor wherein the electric compressor is operated after the refrigerant is preheated.

A transport refrigeration system including a method for fault tolerant power management. The system includes a first sensor identified as required for operation of the transport refrigeration system and a second sensor operable as a backup for the first sensor. The system also includes a first power supply operably connected to the first sensor and configured to operate the first sensor and a second power supply operably connected to the second sensor and configured to operate the second sensor. The system further includes a controller operably connected to at least the first power supply as well as the first sensor and the second power supply as well as the second sensor, the controller configured to monitor at least the first power supply and the second power supply, if a fault is detected in the first power supply, operate the transport refrigeration system from the second sensor.

A vehicle thermal management system includes a switching portion that switches between a state in which a heat medium circulates through a heat-medium cooling heat exchanger and a state in which the heat medium circulates through a heat-medium heating heat exchanger with respect to each of an engine heat-transfer portion and a heat-generating device, a flow-rate adjustment portion that adjusts the flow rate of the heat medium for each of a heat-medium outside-air heat exchanger and the engine heat-transfer portion, an air-conditioning requesting portion that makes a cooling request for an air cooling heat exchanger to cool the ventilation air as well as a heating request for an air heating heat exchanger to heat the ventilation air, and a controller that controls an operation of at least one of the switching portion, a compressor, and the flow-rate adjustment portion based on presence/absence of the cooling request and presence/absence of the heating request from the air-conditioning requesting portion.

A thermal system for an electrified vehicle including a thermal loop and a controller is provided. The thermal loop may include a rear evaporator and a compressor fluidly connected thereto, a conduit to distribute oil throughout the thermal loop, and an evaporator valve. The controller may be programmed to, responsive to receipt of a signal indicating evaporator valve shut-off and detection of a vehicle plug-in event, cycle the compressor to promote oil movement through the compressor. The controller may be further programmed to, responsive to receipt of the signal, open the evaporator valve to force oil back to the compressor. The thermal loop may further include a first expansion valve up stream of a chiller fluidly connected to the compressor, a second expansion valve between the evaporator valve and the rear evaporator, and a third expansion valve up stream of a front evaporator fluidly connected to the compressor.

An air conditioning system for a vehicle, having an evaporator configured for a heat exchange between a coolant and air, a fan configured to generate an air flow passing through the evaporator and intended to be fed into a vehicle passenger compartment, at least one pressure sensor configured to measure the pressure of the coolant, and a control unit to adjust the rotation speed of the fan, configured to automatically decrease the rotation speed of the fan when the detected pressure of the coolant rises above a pressure threshold, so as to reduce the air flow on the evaporator and thus reduce the pressure of the coolant is provided.