An air conditioning system for motor vehicles includes a compressor, a condenser, a plurality of air conditioning units connected in parallel with each other with respect to the compressor and the condenser, and a flow rate control unit configured to, when a specific one of the air conditioning units is additionally turned on or is turned off, prevent occurrence of a sudden change in refrigerant amount in the remaining air conditioning units.

A refrigeration cycle device includes a compressor, an air-refrigerant heat exchanger that exchanges heat between air and refrigerant, an expansion valve decompressing the refrigerant, a heat medium-refrigerant heat exchanger that exchanges heat between a heat medium and the refrigerant, a cold-heat utilization device that utilizes cold heat of the heat medium, and a hot-heat utilization device that utilizes hot heat of the heat medium. A refrigerant flow switching valve is provided to switch between a heat-medium cooling mode of cooling the heat medium in the heat medium-refrigerant heat exchanger, and a heat-medium heating mode of heating the heat medium in the heat medium-refrigerant heat exchanger. In addition, a heat medium flow switching device is provided such that, in the heat-medium cooling mode, the heat medium circulates between the heat medium-refrigerant heat exchanger and the cold-heat utilization device, and that in the heat-medium heating mode, the heat medium circulates between the heat medium-refrigerant heat exchanger and the hot-heat utilization device.

A device for protecting an air conditioning system of a vehicle is configured to prevent damage to an air conditioning system due to excessive operation of a compressor or a deficit of a refrigerant by accurately determining whether to operate the compressor even without using a specific sensor that causes an increase in the manufacturing cost of a vehicle.

Air conditioner for a vehicle in which low pressure protection is accurately performed to improve reliability. A controller adjusts a number of revolution Nc of a compressor 2 so that a detected value does not decrease below a limiting target value TGTs, on the basis of the detected value of a suction temperature sensor and a limiting target value TGTs set to a suction refrigerant temperature of the compressor 2. The controller has a predetermined limiting lower limit TGTsL and a predetermined limiting upper limit TGTsH which is higher than the predetermined limiting lower limit, and adjusts the number of revolution Nc of compressor 2 so that the limiting target value TGTs is the limiting upper limit TGTsH on startup of compressor 2, and the controller gradually decreases the limiting target value TGTs toward the limiting lower limit TGTsL, when the detected value decreases to the limiting upper limit TGTsH.

A control system method is disclosed for air-conditioning a vehicle by a heat pump system, wherein one of multiple operating modes is automatically set, depending on the air-conditioning requirement. The passenger space is cooled by an air-conditioning evaporator and/or is heated by a heating heat exchanger. The heating heat exchanger is arranged in a heating branch of a coolant circuit and is provided with heat via a heat pump. If cooling is required, the heating branch is opened and the heating pump is deactivated. If heating is required, the heating branch is closed and heat is fed to the heating heat exchanger via the heat pump. In order to remove heat from the heating branch, same is opened and a low-temperature cooler, the condenser and the heating heat exchanger are operated connected in series.

An apparatus for a vehicle includes a cooling fan installed in an engine compartment of the vehicle. A fan motor is connected with the cooling fan to drive the cooling fan. A state detector is configured to detect state data, and a controller is configured to control the cooling fan based on the state data when an intake temperature is within a predetermined range, to determine whether the state data satisfies a decision reference condition, and to lock the fan motor according to a change rate of air conditioner refrigerant pressure during a measurement time when the state data satisfies the decision reference condition.

A control system, which may be a Proportional Integral Derivative (PID) control system, controls a component by adjusting the control input and the execution of the control output whenever a change in a state of a component exceeds a certain value. A method is also described.

Disclosed herein is a method for controlling an electromotive compressor in a heat pump system for a vehicle. In accordance with an embodiment of the present invention, an unexpected cutoff of a compressor attributable to overload and the generation of noise and vibration attributable to frequent restarts can be prevented by controlling the number of rotations of the compressor within a specific range based on the discharge pressure of the compressor.

A refrigerant circulation apparatus includes: a vehicle-interior air conditioning (2) that cools an interior of a vehicle; an on-vehicle battery cooler (3) that includes an evaporator for on-vehicle battery cooling (32) that cools an on-vehicle battery mounted on the vehicle; and an electric compressor (5) that compresses and supplies a refrigerant to at least one of the vehicle-interior air conditioning (2) and the on-vehicle battery cooling (3). The apparatus also includes: a temperature sensor (41) that detects a temperature of the electric compressor (5); a pressure sensor (42) that detects a pressure of the refrigerant compressed by the electric compressor (5); and a control unit (40) that restricts operation of the evaporator for on-vehicle battery cooling (32) to reduce load on the electric compressor (5) based on the temperature of the electric compressor (5) and the pressure of the refrigerant.

A refrigeration system includes a startup mode control module that receives an off time of a compressor of the refrigeration system and an ambient temperature, determines whether the off time and the ambient temperature indicate that the compressor is in a flooded condition, and selects, based on the determination, between a normal startup mode and a flooded startup mode. A compressor control module operates the compressor in the normal startup mode in response to the startup mode control module selecting the normal startup mode, in the flooded startup mode in response to the startup mode control module selecting the flooded startup mode, and transitions from the flooded startup mode to the normal startup mode after a predetermined period associated with operating in the flooded startup mode. The compressor is operated at a first speed in the normal startup mode and at a second speed in the flooded startup mode.