A compressor system includes at least two compressors. A suction equalizing tube fluidly couples the at least two compressors. A plumbing assembly fluidly couples to the first compressor and the second compressor. The plumbing assembly comprises an outlet to each compressor of the at least two compressors. A pressure differential between the at least two compressors is created so as to facilitate maintenance of a desired fluid level in the at least two compressors.

The present disclosure provides a multi-air conditioner for heating/cooling operation, including: at least one indoor unit which is installed in a room, and comprises an indoor heat exchanger; an outdoor unit which is connected to the indoor unit through a refrigerant pipe, and comprises an outdoor heat exchanger, a compressor, an outdoor expansion valve, and a four-way valve; at least one leakage blocking valve which is formed on the refrigerant pipe, and blocks a refrigerant flow in the refrigerant pipe when a refrigerant leak occurs from the refrigerant pipe in the room; and a buffer unit which is installed on the refrigerant pipe between the indoor unit and the outdoor unit, and collects refrigerant leaking from the refrigerant pipe. Accordingly, when the refrigerant leaks into the room, it is possible to minimize the amount of the leaking refrigerant by collecting the refrigerant in the buffer tank.

A sensor control system includes: a refrigerant leak sensor configured to, when powered, measure an amount of a refrigerant present in air outside of a heat exchanger of a refrigeration system, where the heat exchanger is located within a building that is at least one of heated and cooled by the refrigeration system; and a power control module configured to one of: continuously power the refrigerant leak sensor; and disconnect the refrigerant leak sensor from power when a blower that moves air past the heat exchanger is on.

A method of controlling a refrigeration system including a medium temperature refrigeration load and a low temperature refrigeration load. The method includes selectively bypassing refrigerant between a medium temperature suction group and a low temperature suction group via a bypass line using an electronic valve positioned in the bypass line. The method also includes controlling flow of refrigerant between the medium temperature suction group and the low temperature suction group via a controller communicatively coupled to the valve, and modulating the valve at any position between a closed position and a full open position to vary an amount of refrigerant flow between the medium temperature suction group and the low temperature suction group in response to determining, via the controller, one or both of a state of the medium temperature suction group and a state of the low temperature suction group.

A lubricant recovery system for a heat exchange system, and a heat exchange system. The heat exchange system includes a compressor, a condenser, an expansion device and an evaporator connected in sequence to form a loop, and further includes a reservoir for storing lubricant and in communication with the compressor, and the lubricant recovery system includes: a first flow path disposed between a suction chamber of the compressor and the reservoir, and having a first pump and a first filter, wherein the first pump is configured to pump a part of the lubricant in the suction chamber to the reservoir, and the first filter is disposed upstream of the first pump for filtering the lubricant; and/or a second flow path disposed between the evaporator and the suction chamber, and having a second pump and a second filter.

A refrigerant amount management system manages an amount of refrigerant with which a plurality of refrigeration cycle apparatuses is filled. Each refrigeration cycle apparatus has a refrigerant circuit. The refrigerant amount management system includes an additional-filling-amount obtaining unit that obtains an additional filling amount of refrigerant with which a refrigeration cycle apparatus has been additionally filled after installation, a storage unit, and a useful-information creation unit. The storage unit stores apparatus information regarding the refrigeration cycle apparatus that has been additionally filled with refrigerant and the additional filling amount of the refrigeration cycle apparatus identified with the apparatus information in association with each other. The useful-information creation unit creates useful information to be used in management of the amount of refrigerant based on the additional filling amount of one of the refrigeration cycle apparatuses and the additional filling amount of another of the refrigeration cycle apparatuses.

The present disclosure provides a system and a method for monitoring an operation of a vapor compression cycle. The method comprises collecting digital representation of observed variables of the operation of the vapor compression cycle over multiple instances of time and executing a constrained ensemble Kalman smoother for each instance of time to estimate the state variables of the vapor compression cycle for each instance of time. The constrained ensemble Kalman smoother updates the state variables over a sequence of time instances within a smoothing window by solving a series of constrained optimization problems in a range of a covariance, for which constraints are enforced for every variable in the smoothing window for every instance of the constrained optimization problems. The method further comprises outputting, based on the estimates of the state variables, estimates of variables of the vapor compression cycle at each instance of time.

A method of measuring the quantity of refrigerant in a refrigeration circuit of a transportation refrigeration unit (TRU). The refrigeration circuit comprises a compressor, a condenser, a receiver, an expansion valve and an evaporator sequentially fluidly connected in a circuit. The method comprises: running the refrigeration circuit in a recovery mode to accumulate the refrigerant in the refrigeration circuit within the receiver; and measuring the quantity of the refrigerant in the refrigeration circuit once it has accumulated within the receiver.

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

A refrigeration cycle apparatus includes a gas leakage sensor and a control device. When refrigerant leakage is detected by the gas leakage sensor, the control device performs a first mode operation to operate a compressor in such a state that a four-way valve is set to a cooling operation state, an expansion valve is opened, and a first shutoff valve is closed. After performing the first mode operation, the control device performs a second mode operation to operate the compressor in such a state that the four-way valve is set to a heating operation state and the first shutoff valve is closed.