Disclosed is an air conditioner. The air conditioner of the present disclosure for achieving the above or other object, there is provided an air conditioner including: a compressor which compresses refrigerant; an accumulator which supplies refrigerant to the compressor; a condenser which condenses refrigerant discharged from the compressor; an expansion valve which expands refrigerant passing through the condenser; an evaporator which has a heat exchange pipe through which refrigerant passing through the expansion valve flows, and evaporates refrigerant flowing through the heat exchange pipe; a gas-liquid separation pipe which connects a first point and a second point located between one end and the other end of the heat exchange pipe; and a bypass pipe which has one end connected to the gas-liquid separation pipe and the other end connected to the accumulator, wherein the gas-liquid separation pipe comprises: a first part which has one end connected to the first point and the other end connected to one end of the bypass pipe; and a second part which extends from the first part at between one end and the other end of the first part, and is connected to the second point.

A water distribution apparatus and method including cold and hot water supplies, a fan coil (or chilled beam device), a control valve having cold and hot water inlets and outlets, cold and hot water outputs configured to supply cold and hot water to the fan coil, cold and hot water return inlets configured to receive from the fan coil the water supplied by the cold and/or water outputs and outputting the cold and/or hot water to the cold and hot water supply lines, respectively, via the cold and hot water outlets, respectively. Cold and hot water is supplied from the cold and/or hot water outputs to the fan coil and received into the cold and hot water return inlets, respectively, and the cold and hot water supplied by the cold and hot water outputs to the fan coil is output to the cold and hot water supply lines, respectively.

A refrigeration cycle device includes: a switching valve configured to switch between a battery mode in which refrigerant flows to a battery heat exchanger and a non-battery mode in which the refrigerant bypasses the battery heat exchanger; and a controller controlling a compressor and the switching valve. The controller includes an estimation unit configured to estimate an oil stagnation amount, which is an amount of lubricating oil accumulated in the battery heat exchanger in accordance with execution of the non-battery mode. The controller includes a determination unit configured to determine whether lubricating oil in the battery heat exchanger needs to be recovered on the basis of the oil stagnation amount. The controller includes an execution unit configured to execute an oil recovery mode for recovery of lubricating oil in the battery heat exchanger when the determination unit determines that lubricating oil needs to be recovered.

A compressor includes: a stator core including a plurality of teeth around which an aluminum winding wire is wound in a concentrated manner; a rotor core disposed on an inner diameter side of the stator core and including a plurality of magnet insertion holes; and a plurality of ferrite magnets inserted in the magnet insertion holes, in which when a width of a winding wire portion formed in each of the teeth is represented as A, a length in an axis direction of the stator core is represented as L, and the number of slots is represented as S, the stator core has a shape that satisfies a relation of 0.3<S×A÷L<2.2.

A cooling device using a refrigeration cycle in which a refrigerant is circulated through a heat receiver, a compressor, a heat radiator, and an expansion valve includes: a gas-liquid separator configured to perform gas-liquid separation on the refrigerant supplied from the expansion valve; a pump configured to send a liquid phase refrigerant separated by the gas-liquid separator to the heat receiver; and a control unit configured to control opening and closing of a refrigerant flow path of the refrigeration cycle, and an operation and stop of the compressor and the pump, wherein the control unit starts the operation of the pump on condition that a net positive suction head of the pump has reached a predetermined value or more.

A cooling system drains oil from low side heat exchangers to vessels and then uses compressed refrigerant to push the oil in the vessels back towards a compressor. Generally, the cooling system operates any number and combination of three different modes of operation: a normal mode, an oil drain mode, and an oil return mode. During the normal mode, a primary refrigerant is cycled to cool one or more secondary refrigerants. As the primary refrigerant is cycled, oil from a compressor may mix with the primary refrigerant and become stuck in a low side heat exchanger. During the oil drain mode, the oil in the low side heat exchanger is allowed to drain into a vessel. During the oil return mode, compressed refrigerant is directed to the vessel to push the oil in the vessel back towards a compressor.

A cooling system includes an ingress port to receive refrigerant in a vapor form from an evaporator, an egress port to return refrigerant in a liquid form back to the evaporator, a condenser coupled to the ingress port and the egress port, and a compressor coupled to the ingress port and the condenser. When the cooling system operates in a first mode, the condenser is configured to receive and condense the refrigerant from the vapor form into the liquid form and to return the refrigerant in the liquid form to the regress port. When the cooling system operates in a second mode, the compressor is configured to compress the refrigerant in the vapor form and to supply the compressed refrigerant to the condenser to be condensed therein.

A continuous heating control system and method, and an air-conditioning device. The system includes a defrosting solenoid valve (1) arranged on a bypass pipeline, wherein one end of the bypass pipeline is connected to an oil separator (2), and the other end of the bypass pipeline is connected to an outdoor heat exchanger (3); and a heating structure which is arranged at the bottom of a gas separator (4) and used for heating the gas separator (4).

Disclosed are a carbon dioxide overlapping type heating system and a control method therefor. The heating system comprises a low-temperature stage loop, a high-temperature stage loop and a heat supply loop, wherein a low-temperature stage compressor (3) and a high-temperature stage compressor (7) are both variable-frequency compressors; and a water pump (10) is a variable-frequency water pump.

A refrigeration cycle apparatus includes; a refrigerant circuit in which a compressor, a heat-source-side heat exchanger, a first expansion device, a second expansion device, and a load-side heat exchanger are sequentially connected by refrigerant pipes and in which refrigerant is circulated; a controller that controls the refrigerant circuit; a bypass pipe extending from a liquid pipe between the first expansion device and the second expansion device toward a suction side of the compressor; a third expansion device provided at the bypass pipe to decompress the refrigerant that flows through the bypass pipe; and a refrigerant cooler provided at the bypass pipe and downstream of the third expansion device to cause heat exchange to be performed between the refrigerant decompressed by the third expansion device and heat generated from the controller.