An air conditioning apparatus includes an electric compressor, an inverter, a temperature detection element, and an ECU. The electric compressor compresses a refrigerant drawn from a refrigerant intake port and discharges the refrigerant from a refrigerant discharge port. The inverter is integrated with the electric compressor so as to be cooled by the drawn refrigerant, and operates the electric compressor according to a control signal. The temperature detection element detects a temperature of the inverter. The ECU outputs a control signal to control the inverter. The ECU performs any one or both of a control for reducing a self-cooling amount of the electric compressor and a control for increasing a self-heat generation amount of the inverter with respect to the inverter when the temperature detected by the temperature detection element is lower than a predetermined reference temperature.

According to one embodiment, a refrigeration cycle apparatus, a fusible plug is attached to a low-pressure-side pipe between an evaporator and a compressor. The refrigeration cycle apparatus includes a heat quantity reduction member. The fusible plug fuses when a temperature of heat transmitted from the low-pressure-side pipe to the fusible plug reaches a predetermined value or more, and then opens the inside of the low-pressure-side pipe to atmosphere. The heat quantity reduction member reduces the quantity of heat to be transmitted to the fusible plug.

A method of cooling a motor coupled to a compressor of a chiller includes adjusting a position of a motor cooling valve located fluidly between the motor and a refrigerant source, using a motor temperature control system coupled to the motor cooling valve to regulate an amount of refrigerant introduced into the motor from the condenser according to a temperature control scheme performed as a function of a monitored temperature in the motor, a first temperature threshold, and a second temperature threshold lower than the first temperature threshold. The temperature control scheme includes a motor cooling control process that adjusts the position of the motor cooling valve based on a stator winding temperature set point relating to stator windings of the motor. A proportionally limited close command override associated with a first temperature range above the second temperature threshold proportionally limits a close command provided to the motor cooling valve.

Systems and methods for controlled subcooling of working fluid in a heating, ventilation, air conditioning and refrigeration (HVACR) system through a suction line heat exchanger are disclosed. The suction line heat exchanger may receive a first fluid flow travelling to a suction of the compressor in the HVACR system and second flow of working fluid that is travelling from a heat exchanger receiving the discharge of the compressor to an expansion device. Superheating of the first working fluid may be determined based on temperature measurements prior to and following the suction line heat exchanger. The superheating may be used to control the quantity of the second flow of working fluid introduced into the suction line heat exchanger, for example to maintain superheat that is below a threshold value. These systems may include chillers and heat pump systems, and methods may be applied to chillers or heat pump systems.

The present disclosure provides an air conditioner. The air conditioner includes a compressor; a sensor for measuring the compressors state configured to detect compressor state information that includes at least one of a pressure value and a saturation temperature of the compressor; and a controller configured to control air flow on the side of an indoor unit by comparing the compressor state information measured from the sensor and a threshold.

Provided is an air conditioning apparatus that is capable of suppressing increases in volume and cost of the apparatus and performing more suitable overheating protection. An electric compressor is an inverter-integrated electric compressor integrally including a compressor, an electric motor that drives the compressor, and an inverter including a temperature sensor that detects the temperature in the vicinity of a semiconductor switching device, wherein a controller estimates a discharge temperature of the compressor on the basis of a correlation of respective pressure loading characteristics for the detected temperature of the inverter, for the rotational speed of the compressor, and for the motive force of the compressor in a refrigerating cycle.

A combined heat exchanger, a heat exchange system, and an optimization method thereof are provided. The heat exchange system includes: an enhanced vapor injection compressor, a condenser, an expansion valve and an evaporator, which are located in a main circuit; wherein the heat exchange system further includes a first branch branched from the main circuit to an vapor injection port of the compressor at a branch point P downstream of the condenser, and a first heat exchange unit and a second heat exchange unit are further provided in the main circuit between the branch point P and the expansion valve; and wherein a refrigerant leaving the condenser is divided at the branch point P into a first portion passing through the first heat exchange unit and the second heat exchange unit from the main circuit, and a second portion passing through the first branch to the vapor injection port.

A heat exchanger, in which refrigerant causing disproportionation is used, includes a main heat exchange unit including a plurality of first heat transfer pipes arranged side by side, a sub-heat exchange unit including a plurality of second heat transfer pipes arranged side by side, and a relay unit including a plurality of relay passages connecting the plurality of first heat transfer pipes and the plurality of second heat transfer pipes. Each of the plurality of relay passages has one inlet connected to a corresponding one of the plurality of second heat transfer pipes, and a plurality of outlets each connected to a corresponding one of the plurality of first heat transfer pipes. Each of the plurality of relay passages distributes the refrigerant flowing from the one inlet, without merging streams of the refrigerant together, and causes the refrigerant to flow out of the plurality of outlets.

It is determined whether thermo-off postponement control is allowed or not on the basis of a current compressor operating frequency when a thermo-off condition is satisfied. If it is determined that thermo-off postponement control is allowed, the thermo-off postponement control in which a lowest operating frequency in an operating frequency range of a compressor is temporarily reduced within a range greater than or equal to a minimum operating frequency of the compressor in use so as to continue an operation. If it is determined that thermo-off postponement control is not allowed, thermo-off of stopping the compressor is performed.

Stress to be imposed on a compressor in reverse cycle operation is reduced. A cycle controller causes an outdoor heat exchanger to function as a condenser and an indoor heat exchanger to function as an evaporator when a reverse cycle executing condition is met, so that a refrigerant circulates in reverse of a heating cycle. A rotation speed controller adjusts a rotation speed of a compressor in a reverse cycle, depending on an index correlated with an amount of frost on the outdoor heat exchanger at a start of the reverse cycle. The rotation speed controller decreases the rotation speed of the compressor in the reverse cycle as the index at the start of the reverse cycle indicates that the amount of the frost on the outdoor heat exchanger is smaller.