A method for adaptive power engine control of a transport refrigeration unit (TRU) is provided. The method includes determining a current compressor power of a compressor of the TRU. The method also includes determining an adaptive compressor power error of the compressor. Also, the method includes calculating and setting a target compressor power of the compressor based on the current compressor power and the adaptive compressor power error. Further, the method includes determining a suction pressure control point of the compressor based on the target compressor power and a compressor curve map. Moreover, the method includes operating the compressor with the suction pressure control point of the compressor.

A refrigeration unit includes an evaporator circulating a flow of refrigerant therethrough to cool a flow of compartment air flowing over the evaporator, a compressor in fluid communication with the evaporator to compress the flow of refrigerant, an engine operably connected to the compressor to drive operation of the compressor, an expansion device in fluid communication with the flow of refrigerant, and a controller operably connected to at least the engine and the expansion device. The controller is configured to determine an available power to drive the compressor, determine a compressor discharge pressure upper limit based on the available power, compare the compressor discharge pressure upper limit to a requested compressor discharge pressure, and initiate adjustment of the expansion device such that an actual compressor discharge pressure is the lesser of the requested compressor discharge pressure or the compressor discharge pressure upper limit.

There is provided a vehicle air conditioner which is capable of smoothly achieving a dehumidifying and heating mode without using an evaporation pressure adjustment valve, so that cost reduction is achievable. A controller executes a normal mode to control an operation of a compressor 2 on the basis of a radiator pressure PCI and control a valve position of an outdoor expansion valve 6 on the basis of a heat absorber temperature Te, and in this normal mode, when the valve position of the outdoor expansion valve 6 is maximized but the heat absorber temperature Te falls, the controller shifts to a heat absorber temperature control mode to control the operation of the compressor 2 on the basis of the temperature of a heat absorber 9 and generate heat from an auxiliary heater 23.

A refrigeration cycle device includes: a first expansion valve that decompresses a refrigerant flowing out of a high-pressure side heat exchanger; an exterior heat exchanger that exchanges heat between the refrigerant flowing out of the first expansion valve and outside air; a second expansion valve that decompresses the refrigerant flowing out of the exterior heat exchanger; a low-pressure side heat exchanger arranged in series with the exterior heat exchanger; a cooler core that exchanges heat between the heat medium cooled by the low-pressure side heat exchanger and air to be blown into a vehicle interior to cool the air; and a controller configured to switch between a heat absorption mode and a heat dissipation mode by adjusting an amount of decompression in each of the first expansion valve and the second expansion valve.

An evaporator apparatus for a refrigeration cycle of an HVAC system or a refrigeration system is disclosed that includes: a primary evaporator pathway for a working fluid of the refrigeration cycle extending through a primary expansion device and a primary evaporator; a secondary evaporator pathway for the working fluid in parallel with the primary evaporator pathway and extending through a secondary expansion device and a secondary evaporator; a coolant circuit for cooling a device, the secondary evaporator configured for heat exchange between the working fluid and process fluid of the coolant circuit; and a controller configured to control: the primary expansion device to maintain a target superheat of working fluid at a primary control location downstream of the primary evaporator; and the secondary expansion device based on monitoring a temperature of process fluid to maintain a target temperature of process fluid at a coolant control location in the coolant circuit.

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.

Vehicle air conditioning device executes the dehumidifying mode in which a controller lets refrigerant discharged from compressor 2 radiate heat in radiator 4, decompresses the refrigerant from which heat has been radiated and then lets the refrigerant absorb heat in heat absorber 9 and outdoor heat exchanger 7, or lets the refrigerant discharged from compressor 2 radiate heat in radiator 4 and outdoor heat exchanger 7, decompresses the refrigerant from which heat has been radiated and then lets the refrigerant absorb heat in heat absorber 9. In the dehumidifying mode, the controller executes simple control to compare a target value of an index that is a basis of control of the outdoor expansion valve with an actual detected value and to change a valve position of the outdoor expansion valve from a magnitude relation between the value in an enlarging direction or a reducing direction as much as a constant value.

A vehicle heat management device includes a first circulator section, a second circulator section, and a flow rate change section. The first circulator section is provided at a first flow path of a first circulation path, and circulates a first heat exchange medium in the first circulation path, the first flow path passing a first heat exchanger, a second flow path passing a first expansion valve and a second heat exchanger, a third flow path passing a second expansion valve and a heat absorption section. The second circulator section circulates a second heat exchange medium in a second circulation path configured by a fourth flow path passing a heat generating body, a fifth flow path passing a radiator, and a sixth flow path passing a heat dissipating section and the first heat exchanger. The flow rate change section increases a flow rate of the second heat exchange medium.

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.

An embodiment method for controlling a heating, ventilation, and air conditioning (HVAC) system of a vehicle includes determining a target subcooled temperature of a refrigerant based on a temperature and a pressure of the refrigerant discharged from an outlet of a compressor when the compressor operates, calculating a change in enthalpy of the refrigerant based on the determined target subcooled temperature in a process of condensing and subcooling the refrigerant, calculating a change in enthalpy of air passing over an exterior surface of a condenser based on the calculated refrigerant enthalpy change, and calculating a required fan duty of a cooling fan based on the calculated air enthalpy change, wherein the cooling fan is configured to blow the air to the condenser.