A heat pump system includes a first bypass pipe provided with a first bypass valve and connecting a liquid refrigerant pipe and a low-pressure refrigerant pipe, a refrigerant heat exchanger configured to cause a heat-exchange between refrigerant flowing in the liquid refrigerant pipe and refrigerant flowing in first bypass pipe, a second bypass pipe provided with a second bypass valve and connecting the liquid refrigerant pipe and the low-pressure refrigerant pipe, and a controller. The controller is configured to control opening degree of the first bypass valve based on detected superheated temperature of refrigerant flowing in the first bypass pipe, and detected discharge temperature of a compressor and control opening degree of the second bypass valve based on the detected discharge temperature.

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 (10) integrally including a compressor (5), an electric motor (6) that drives the compressor (5), and an inverter (7) including a temperature sensor (11) that detects the temperature in the vicinity of a semiconductor switching device, wherein a controller (3) estimates a discharge temperature of the compressor (5) on the basis of a correlation of respective pressure loading characteristics for the detected temperature of the inverter (7), for the rotational speed of the compressor (5), and for the motive force of the compressor (5) in a refrigerating cycle (2).

Provided are a control method and apparatus for increasing the amount of a circulating refrigerant, and an air conditioner. The control method includes: when a refrigerating capacity need is equivalent to a heating capacity need in the operation of an air-conditioning system, determining whether the discharge temperature of a compressor is greater than a preset safety alert value; if the discharge temperature of the compressor is greater than the safety alert value, adjusting the frequency of a fan of an outdoor heat exchanger; and when the discharge temperature of the compressor is not greater than the safety alert value, controlling to stop the adjustment of the frequency of the fan, and maintaining the air-conditioning system to operate at the adjusted current frequency of the fan.

Systems and methods for operating a water recovery system and include activating a plurality of dampers, a fan, and a refrigeration system of the water recovery system. The method includes measuring an ambient air temperature of the water recovery system based on data obtained from an ambient air temperature sensor. The method includes measuring one or more evaporator temperatures associated with an evaporator of the water recovery system based on data obtained from one or more evaporator temperature sensors. The method includes determining an optimal evaporator air temperature of the water recovery system based on the one or more evaporator temperatures and the ambient air temperature. The method includes setting a speed of the fan of the water recovery system based on the optimal evaporator air temperature.

An air conditioner unit includes a variable speed compressor for circulating refrigerant through refrigeration loop and a controller configured to initiate an operating cycle, start a compressor transition timer, and determine an unfiltered compressor speed. The unfiltered compressor speed is fixed based on the selected operating mode until the compressor transition timer reaches a predetermined transition delay time, after which the unfiltered compressor speed is determined using a closed loop feedback control algorithm. The controller is further configured to operate the variable speed compressor at a target compressor speed that is modified from the unfiltered compressor speed based on the identification of a speed modification condition, such as a dehumidification deficiency, a speed restriction, or the identification of one or more resonance avoidance zones.

A refrigeration cycle apparatus includes a refrigeration cycle circuit that has a compressor, a condenser, an expansion device, and an evaporator that are connected through a pipe, the refrigeration cycle circuit being configured to allow refrigerant to circulate in the refrigeration cycle circuit, and a controller configured to determine whether the refrigerant leaks or whether the expansion device malfunctions on the basis of a degree of subcooling at an outlet of the condenser and a degree of superheat at an outlet of the evaporator or a degree of superheat at a suction port of the compressor.

Included are: a compressor including a compression mechanism that compresses refrigerant, and a motor that drives the compression mechanism; an inverter that applies desired voltage to the motor; an inverter controller that controls the inverter; a high-pressure switch that operates when a discharge pressure of the compressor becomes a preset pressure or higher; and a thermal protector that operates when the temperature of the compressor becomes a preset temperature or higher, wherein the high-pressure switch and the thermal protector are installed on a power supply line for supplying power to the inverter, and the high-pressure switch is opened when the discharge pressure of the compressor becomes the preset pressure or higher, or the thermal protector is opened when the temperature of the compressor becomes the preset temperature or higher, to interrupt power supply to the inverter.

A refrigeration cycle device includes: a compressor having a compression mechanism forming a compression chamber for compressing refrigerant, and a cooled portion cooled by the refrigerant before being compressed by the compression mechanism; a radiator that radiates the refrigerant compressed by the compressor; a decompressor that decompresses the refrigerant radiated by the radiator; an evaporator that evaporates the refrigerant decompressed by the decompressor; an acquisition unit that acquires the state of the refrigerant after cooling the cooled portion and before flowing into the compression chamber; and a control unit that controls the superheat degree of the refrigerant flowing into the compression chamber based on the state of the refrigerant acquired by the acquisition unit.

A slot includes a coil housing portion having first and second side portions and a bottom portion. A first straight line connects first and second points which are boundaries between the bottom portion and the side portions. A slot opening has third and fourth points closest to the first and second side portions. A second straight line connects the first and third points. A third straight line connects the second and fourth points. A first region is surrounded by the first straight line and the bottom portion. A second region is surrounded by the second straight line and the first side portion, and is surrounded by the third straight line and the second side portion. A third region is surrounded by the three straight lines. Areas A1, A2 and A3 of the three regions and total cross-sectional areas S1, S2, S3 of coils therein satisfy (S1/A1)>(S2/A2)>(S3/A3).

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.