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.

In a refrigeration cycle device, a variable throttle mechanism is provided in a refrigerant passage that connects an evaporator and a compressor, and is configured to be capable of changing a passage cross-sectional area of the refrigerant passage. A radiator includes a plurality of tubes and a header tank. The plurality of tubes, through which the refrigerant discharged from the compressor flows, are stacked in a stacking direction. The header tank is provided at an end side in a longitudinal direction of each of the plurality of tubes and communicates with the plurality of tubes. A tank interior space of the header tank is partitioned into a plurality of sections that are arranged in the stacking direction. The header tank includes an opening/closing mechanism configured to open or close a communication portion that causes adjacent ones of the plurality of sections to communicate with each other.

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 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 thermal system for a vehicle includes a compressor configured to pressurize refrigerant that selectively flows through a chiller for battery coolant and an evaporator for cabin cooling. The system further includes a controller programmed to, responsive to cabin cooling demand becoming zero, change from adjusting compressor speed responsive to changes in an evaporator temperature to adjusting compressor speed responsive to changes in a chiller refrigerant pressure.

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.

A vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.

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 vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.

A vehicle air conditioning apparatus is provided that can prevent temperature variations of the air after the heat exchange in a radiator to reliably control the temperature of the air supplied to the vehicle interior. During the heating operation and the heating and dehumidifying operation, target degree of supercooling SCt when target air-blowing temperature TAO is a predetermined temperature or higher is set to SCt1 that is greater than SCt2 when the target air-blowing temperature TAO is lower than the predetermined temperature. When amount of air Ga supplied from indoor fan 12 is lower than a predetermined value, the target degree of supercooling SCt is corrected, which is set such that the degree of supercooling is lower than target degree of supercooling corrected when the amount of air Ga supplied from the indoor fan 12 is a predetermined value or higher.