An air conditioner is provided. The air conditioner may include a compressor to compress a refrigerant, at least one oil sensor disposed in the compressor to detect oil stored in the compressor, an oil separator to separate the oil from the refrigerant discharged from the compressor, a first collection tube to collect the oil separated by the oil separator into the compressor, a second collection tube disposed at a height different from a height of the first collection tube, an oil valve disposed in the second collection tube, and a controller to control the oil valve on the basis of information detected by the oil sensor.

A chiller system is provided and includes a chiller, a lubrication assembly and a controller. The chiller includes a compressor, a condenser, an expansion assembly and an evaporator in fluid communication with one another. The lubrication assembly is operably coupled to the compressor, the condenser and the evaporator and is formed to define first-third pathways via a three-way valve and a fourth pathway. The first pathway is configured for pumping refrigerant through the chiller, the second pathway is configured for pre-storing refrigerant in the chiller, the third pathway is configured for removing refrigerant from the chiller and the fourth pathway is configured for charging refrigerant into the chiller. The controller is configured to control the lubrication assembly to selectively engage one of the first-fourth pathways.

A heat exchanger includes: heat transfer tubes aligned in an up-down direction; a liquid header connected to ends of the heat transfer tubes; and connection tubes aligned in the up-down direction and connected to the liquid header. The heat transfer tubes include: a first heat transfer tube disposed at a lowermost position; and a second heat transfer tube disposed above and adjacent to the first heat transfer tube. The connection tubes include: a first connection tube disposed at a lowermost position; and a second connection tube disposed above the first connection tube. The liquid header includes: a first flow path connected to the first connection tube and the first heat transfer tube; and a second flow path connected to the second connection tube and the second heat transfer tube.

An internal oil filter is installed at least partially inside a crankcase and/or an oil sump of a compressor. The internal oil filter can receive oil from an oil pressure regulator and filter the oil via filter media. The received oil radially penetrates through the filter media and flow directly into the oil sump from an outside surface of the filter media. This can eliminate the need of fluid lines connecting an outlet of an oil filter to the oil sump and any sealing mechanism therebetween.

A scroll compressor includes fixed and movable scrolls, and a drive part. The fixed scroll has a fixed-side end plate, a fixed-side lap, and a thrust sliding portion surrounding the first lap. The movable scroll has a movable-side end plate and a movable-side lap. The drive part revolves the movable scroll so that refrigerant in a compression chamber formed by the fixed-side lap and movable-side lap is compressed. A back-pressure space which communicates with the compression chamber for at least a prescribed period in a revolution cycle is formed at the back face side of the movable scroll. A first oil channel supplied with oil from a space is formed in a first angle region of the fixed-side end plate. A communication channel formed in a second angle region communicates with the compression chamber. A second oil channel communicating with the back-pressure space is formed in the second angle region.

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.

Systems and methods for lubricant management of a compressor in an HVACR system are disclosed. A heat transfer circuit can utilize a working fluid to provide heating or cooling includes a compressor for compressing the working fluid and a heat source configured to increase a suction temperature of the working fluid entering the compressor. One or more lubricant rheological properties in a compressor system based on measurements taken at or near a bearing cavity of the compressor are determinable. A lubricant reservoir can be in thermal communication with a discharge flow path of the compressor. An internal heat exchanger can be disposed within a compressor for improving viscosity of the lubricant to be cycled back into the compressor. A heater can be located on a fluid line between a lubricant separator and a lubricant inlet. Condenser fans can be controlled.

An oil separation device includes a container, an inlet pipe, an outlet pipe, an oil return pipe, and an oil return regulating valve. The container includes a separation chamber, a storage chamber, and a partition portion. The oil return regulating valve is connected to the oil return pipe. The partition portion is configured to allow the refrigeration oil separated from the fluid mixture to flow from the separation chamber to the storage chamber. The oil return regulating valve is configured to regulate the quantity of refrigeration oil that is returned from the storage chamber to the compressor.

An apparatus includes a high side heat exchanger, a flash tank, a first load, a first oil separator, and a first compressor. The high side heat exchanger removes heat from a refrigerant. The flash tank stores the refrigerant. The first load uses the refrigerant to cool a first space proximate the first load. During a first mode of operation, the first oil separator separates an oil from the refrigerant from the first load and directs the refrigerant to an ejector. The ejector directs the refrigerant from the high side heat exchanger and the refrigerant form the first oil separator to the flash tank. The flash tank directs the refrigerant from the first oil separator to the first compressor. The first compressor compresses the refrigerant from the flash tank. During a second mode of operation, the first oil separator directs the oil separated from the refrigerant to the first compressor.

A liquid slug protector device for air conditioning and heat pump systems can include a housing having an inlet port, an outlet port, an abutment surface, and a cavity. The device can include a piston disposed in the cavity. The piston can have a primary channel. The device can include a secondary channel. A first refrigerant flow path extending between the inlet port and the outlet port can include the primary channel. A second refrigerant flow path extending between the inlet port and the outlet port can include the secondary channel. The second refrigerant flow path can be closed when the piston abuts against the abutment surface.