A vehicle air conditioning device is provided which is capable of accurately judging the need for temperature regulation of an object of temperature regulation mounted in a vehicle and efficiently performing temperature regulation. A compressor 2 to compress a refrigerant, an indoor heat exchanger (radiator 4 and heat absorber 9) for exchanging heat between air supplied to a vehicle interior and the refrigerant, an outdoor heat exchanger 7 disposed outside the vehicle interior, and a control device 11 are provided to perform air conditioning of the vehicle interior. An equipment temperature adjusting device 61 for adjusting the temperature of the object of temperature regulation mounted in the vehicle is provided. The control device controls the equipment temperature adjusting device 61 on the basis of a gradient (ΔTw) of a change in an index indicating the temperature of the object of temperature regulation.

A refrigerant cycle device includes a compressor, a radiator, a first expansion valve, a second expansion valve, a first evaporator, a second evaporator, and a controller. The controller is configured to switch between a first evaporator priority control and a second evaporator priority control. During the first evaporator priority control, the controller controls a throttle opening of the second expansion valve based on at least one of a temperature of a first evaporator, a temperature of a refrigerant flowing through the first evaporator, and a temperature of an air having exchanged heat in the first evaporator. During the second evaporator priority mode, the controller controls the throttle opening based on a refrigerant state of the second evaporator. When the at least one of the temperatures is equal to or greater than a switching temperature, the second priority mode is switched to the first priority mode.

A refrigerant management system in a heat flux management system for an electric vehicle and a method of refrigerant management is provided. The system includes a vehicle air conditioning circuit including a heat pump circuit and a refrigeration cycle refrigerant circuit, the air conditioning circuit including a heat pump condenser in thermal communication with a heat source, a refrigerant evaporator in thermal communication with the heat source, an evaporator associated with an expansion valve, and a refrigerant compressor where the components are fluidly connected to one another by a refrigerant line. An accumulator is fluidly coupled in the refrigerant line downstream of the heat pump condenser, the refrigerant evaporator and evaporator and upstream of the refrigerant compressor, and the air conditioning circuit is switchable between a heating mode and a cooling mode in which the refrigerant circuit is in fluid communication with the compressor by actuation of at least one valve.

A heat pump includes a refrigerant loop. The refrigerant loop includes a first heat exchanger, a first region of a second heat exchanger, a third heat exchanger, a fourth heat exchanger, a compressor, a vapor generator, an accumulator, a first expansion valve, and a first three-way valve. The compressor includes a low-pressure inlet, a mid-pressure inlet, and an outlet. The vapor generator is positioned downstream of the outlet of the compressor and upstream of both the low-pressure inlet and the mid-pressure inlet. The accumulator is positioned immediately upstream of the compressor. The accumulator includes an inlet and an outlet. The first expansion valve is positioned upstream of the accumulator. The first expansion valve includes an inlet and an outlet. The first three-way valve is positioned immediately downstream of the first expansion valve and immediately upstream of the accumulator.

A method for operating a coolant circuit of a refrigeration system of a vehicle having multiple system sections. A single pressure sensor is located in each system section. A temperature sensor is arranged downstream at each component to be balanced in the system sections, such as heat exchangers and a coolant compressor. The sensor signals of the pressure and temperature sensors are supplied to a control unit for the control or regulation of the refrigeration system. Furthermore, a pressure approximation value at the position of the temperature sensor is calculated by a pressure loss value determined using a pressure loss calculation function starting from the position of the pressure sensor arranged in the system section of the component up to the position of the temperature sensor if the temperature sensor and the pressure sensor are arranged at different positions in the system section.

Disclosed therein are a heat pump system for a vehicle and a method of controlling the heat pump system, which determines that frosting begins on an exterior heat exchanger and carries out a defrosting control if a difference value between outdoor temperature and refrigerant temperature of an outlet side of the exterior heat exchanger is above a frosting decision temperature in a heat pump mode, thereby increasing frost-prevention and defrosting effects and enhancing heating performance and stability of the system because the system recognizes the beginning of frosting on the exterior heat exchanger at a proper time so as to carry out the defrosting control.

In a motor lock determination device (1), a lock determination on an electric motor (7) is performed such that: a first detection value (PI), which is a detection value (P) of a refrigerant pressure sensor (17) during a stop of an electric fan (5), is detected, and a second detection value (P2), which is a detection value (P) of the refrigerant pressure sensor (17) after the electric fan (5) is driven for a first predetermined time (Δ), is detected; when the second detection value (P2) is equal to the first detection value (PI) or more than the first detection value (PI), it is determined that a motor lock occurs; and when the second detection value (P2) is less than the first detection value (PI), it is determined that no motor lock occurs.

A vehicle air conditioning device is provided which is capable of accurately judging the need for temperature regulation of an object of temperature regulation mounted in a vehicle and efficiently performing temperature regulation. A compressor 2 to compress a refrigerant, an indoor heat exchanger (radiator 4 and heat absorber 9) for exchanging heat between air supplied to a vehicle interior and the refrigerant, an outdoor heat exchanger 7 disposed outside the vehicle interior, and a control device 11 are provided to perform air conditioning of the vehicle interior. An equipment temperature adjusting device 61 for adjusting the temperature of the object of temperature regulation mounted in the vehicle is provided. The control device controls the equipment temperature adjusting device 61 on the basis of a gradient (ΔT.sub.w) of a change in an index indicating the temperature of the object of temperature regulation.

Methods and system for operating a heat pump in different operating modes and providing a predictable heat pump response when the heat pump is transitioned between the different operating modes are presented. In one example, a controller that includes executable instructions for providing a bumpless compressor command for operating the heat pump is disclosed.

A vehicle includes a vapor-injection heat pump having a refrigerant loop with an evaporator configured to cool cabin air, the evaporator coupled to an electronically controllable pressure regulating valve having a fully-open position with near-zero pressure drop, and a cabin conditioning coolant loop having a heater core configured to selectively heat the cabin air. A controller is configured to control the valve to maintain temperature and pressure of the refrigerant loop above a freezing threshold to inhibit or prevent evaporator icing. The valve may be controlled to throttle flow during a parallel dehumidification mode and to fully open to minimize pressure drop during other operational modes, such as a cooling mode, heating mode, de-icing mode, and series dehumidification mode.