The present disclosure relates to controls and related methods for mitigating liquid (e.g., compressor refrigerant, etc.) migration and/or floodback.

A cooling system is designed to generally allow for one or more compressors to be bypassed when ambient temperatures are low. The system includes a bypass line and valve that opens when ambient temperatures are low and/or when the pressure of the refrigerant in the system is low. In this manner, the refrigerant can flow through the bypass line instead of through one or more compressors. These compressors may then be shut off. To supply any needed pressure to cycle the refrigerant, the system may include a pump that turns on when the bypass line is open. When ambient temperatures are extremely low, thermosiphon may be used to cycle the refrigerant.

A transport refrigeration device, a power management system and a power management method thereof are provided by the present disclosure. The transport refrigeration device includes a power source (110), a compressor (120) and a generator (130) both driven by the power source (110), a refrigerant in a refrigeration circuit which is compressed by the compressor (120), a battery (140) powered by the generator (130), an electrically driven component (150) in the refrigeration circuit which is powered by the generator (130) and/or the battery (140), and a control module (151), and wherein the power management method includes: adjusting an output power of the power source (110) and/or an input power of the compressor (120) and/or charge and discharge statuses of the battery (140), by limiting an upper limit and/or a lower limit of an output power of the generator (130) through the control module (151).

A compressor (10) includes a casing (20), a terminal (29) protruding from the casing, a first cover (70) covering the terminal, and a second cover (50) covering the first cover.

The unloading of multi-stage compressors may include the introduction of flow from a gas bypass from a condenser into a second-stage inlet duct to induce a swirl in the flow into second stage compression. This unloading may be performed on multi-stage compressors in heating, ventilation, air conditioning and refrigeration (HVACR) circuits that include a gas bypass from a condenser to the second-stage inlet housing of the compressor. The multi-stage compressor may include an impeller inlet duct including a flow straightener receiving fluid flow from the first stage discharge, and one or more channels to introduce gas from the gas bypass into the flow passing through the impeller inlet duct. The flow introduced by the channels may have a direction of flow including a component opposite to the direction of flow of the fluid flow from the first stage discharge via the flow straightener.

A system for controlling a capacity of a compressor includes a motor of the compressor including a main winding connected at a connection point to an auxiliary winding and a drive configured to control a speed of the motor. The system includes a first switch configured to selectively connect the main winding to either a first line voltage or a first output of the drive, a second switch configured to selectively connect the connection point to either a second line voltage or a second output of the drive, and a third switch configured to selectively connect the auxiliary winding to either a capacitor or a third output of the drive. The system includes a solenoid valve configured to selectively either operate in a first capacity or a second capacity. The system includes a control module configured to control the drive, the first switch, the second switch, and the third switch.

There is provided an inverter-integrated electric compressor which makes it possible to effectively suppress noise caused by a common mode current while achieving a size reduction. The inverter-integrated electric compressor includes an inverter device 3 which has upper and lower arm switching elements 13 and 16 and applies a three-phase AC output to a motor M. The inverter-integrated electric compressor injuries a control board which controls the switching of the upper and lower arm switching elements 13 and 16, and a bus bar assembly 22 provided to establish wiring among a battery 24, the control board, the upper and lower arm switching elements 13 to 18, and the motor M. A normal mode coil 40, a three-phase common mode coil 41, a ferrite core 42, reflux capacitors 43 and 44, and a snubber circuit 52 are arranged in the bus bar assembly 22.

A cooling system is designed to generally allow for one or more compressors to be bypassed when ambient temperatures are low. The system includes a bypass line and valve that opens when ambient temperatures are low and/or when the pressure of the refrigerant in the system is low. In this manner, the refrigerant can flow through the bypass line instead of through one or more compressors. These compressors may then be shut off. To supply any needed pressure to cycle the refrigerant, the system may include a pump that turns on when the bypass line is open. When ambient temperatures are extremely low, thermosiphon may be used to cycle the refrigerant.

A valve for a refrigeration system and a method of forming a valve includes a dual piston assembly having an inner piston (44) and an outer piston (42) that are moveable relative to each other to control pressure equalization flow through the valve, and an adjustable control stem (66) engageable with the outer piston that enables a low fluid equalization flow when in a first position and a variably higher fluid equalization flow when in a variable second position. The inner piston has a plurality of bleed orifices (46, 48) that are openable by movement of the outer piston relative to the inner piston.

A cooling system includes a heat exchange unit; a supply line configured to send a coolant to the heat exchange unit; a drain line configured to send the coolant drained from the heat exchange unit; a first to a n.sup.th gas-liquid separating units connected in series to a gas line in which a gas of the coolant flows; a first to a n.sup.th cooling lines extended via the first to the n.sup.th gas-liquid separating units, respectively. Both ends of the first cooling line are connected to a cooling device. The second to the n.sup.th cooling lines are provided between the drain line and a first to a (n1).sup.th liquid lines via the second to the n.sup.th gas-liquid separating units, respectively. The first to the n.sup.th gas-liquid separating units are respectively connected to liquid lines, and the liquid lines communicate with the supply line connected to the heat exchange unit.