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 multi-split air conditioning system and liquid return prevention control method thereof. When the multi-split air conditioning system is in heating operation, the multi-split air conditioning system is switched to a defrosting mode to operate for defrosting if an outdoor unit receives a defrosting instruction. After detecting gas exhaust pressure, gas return pressure and gas exhaust temperature of a compressor in real time, the multi-split air conditioning system sends a defrosting completion signal to a diverter, controls the compressor to reduce frequency and a plurality of electric-control valves to open, and controls any one of the electric-control valves to open and the rest of the electric-control valves to close during reversing of a four-way valve, so as to reduce the amount of a refrigerant returned to a low-pressure gas-liquid separator.

A method of managing a compressor start operation, the method includes controlling a valve disposed upstream of a compressor to lower a saturated suction temperature of a refrigerant to be below an ambient temperature while starting the compressor.

A fluid injection control system, a fluid injection control method and a fluid circulation system including the fluid injection control system are provided. The fluid injection control system includes an injection valve, control apparatus and energy storage apparatus. The injection valve is arranged in a path along which a fluid flows into a device; the energy storage apparatus is configured to supply, in response to the control apparatus being powered off, power to the control apparatus so as to maintain an operation of the control apparatus.

A heat exchanger system that includes a heat exchanger that includes a plurality of circuits wherein the heat exchanger is configured to exchange heat between a refrigerant and a working fluid. The heat exchanger system also includes a valve configured to fluidly couple a circuit of the plurality of circuits to a flow path of the refrigerant. Further, the heat exchanger system includes a controller that is configured to receive feedback indicative of an operating parameter of the heat exchanger system and actuate the valve based on the operating parameter.

A cooling system uses P-traps to address the oil return issues that result from a vertical separation between the compressor and the high side heat exchanger. Generally, the vertical piping that carries the refrigerant from the compressor to the high side heat exchanger includes P-traps installed at various heights to capture oil in the refrigerant and to prevent that oil from flowing back to the compressor. T-connections are coupled to the P-traps to allow the oil to drain out of the P-traps. The oil may then be collected and returned to the compressor.

A cooling system uses P-traps to address the oil return issues that result from a vertical separation between the compressor and the high side heat exchanger. Generally, the vertical piping that carries the refrigerant from the compressor to the high side heat exchanger includes P-traps installed at various heights to capture oil in the refrigerant and to prevent that oil from flowing back to the compressor. As oil collects in the P-traps, the refrigerant begins to push the oil upwards until the oil reaches the high side heat exchanger. Multiple piping of different sizes may be used depending on a discharge pressure of the compressor. When the discharge pressure is higher, a larger piping may be used direct the oil and refrigerant to the high side heat exchanger.

A heat pump may include a compressor configured to compress a refrigerant, a first temperature sensor provided in heating pipes connected to a heating device that heats an indoor space to sense a temperature of fluid flowing through the heating pipes, and a controller. The controller may be configured to determine whether a boiler is operating to heat an indoor space or is operating to supply hot water based on a sensing value of the first temperature sensor. The compressor may operate when the controller determines that the boiler is not operating to heat the indoor space and/or determines that the boiler is operating to supply hot water.

Various embodiments of a multi-evaporator sealed vapor compression system for an appliance are provided. In one example aspect, a sealed system charged with a refrigerant fluid includes a single compressor and a first and second evaporator fluidly coupled in series. A flash tank is positioned between the evaporators. One or more valves are fluidly coupled with and positioned downstream of the flash tank and the second evaporator. The valves are operable to selectively switch the flow of refrigerant fluid between the two evaporators at a frequency such that the temperature rise in the evaporators is negligible. In another aspect, a sealed system charged with a refrigerant fluid includes a single compressor and a first and second evaporator fluidly coupled in parallel. One or more valves positioned upstream of the evaporators and one or more valves are positioned downstream of the evaporators for controlling the refrigerant flow through the sealed system.

Provided is an air conditioning apparatus. The air conditioning apparatus includes an outdoor unit which includes a compressor and an outdoor heat exchanger and through which a refrigerant is circulated, an indoor unit through which water is circulated, a heat exchanger in which the refrigerant and the water are heat-exchanged with each other, a water tube configured to guide the water circulated through the indoor unit and the heat exchanger, a pump installed in the water tube, and a controller configured to analyze an output signal of the pump so as to calculate a ration of an air layer in the water tube, the controller being configured to control a target supercooling degree or target superheating degree of the heat exchanger according to the calculated ratio of the air layer.