An air-conditioning system includes a plurality of indoor units, an outdoor unit, a refrigerant pipe including a branch portion and being divided into a plurality of flow sections, a plurality of control valves, a plurality of pressure sensors, and a controller. The control valves include indoor-unit control valves, and a plurality of pipe control valves. The pipe control valves include a plurality of indoor-side pipe control valves provided between the branch portion and the indoor units. The pressure sensors include a plurality of indoor-side pressure sensors connected to the controller and provided between the indoor-unit control valves and the indoor-side pipe control valves. The controller opens or closes the control valves, compares a pressure of refrigerant to a predetermined threshold, and detects refrigerant leaking in the flow section where a pressure of refrigerant measured is determined to be lower than the predetermined threshold.

A divided aircraft galley refrigeration system is disclosed. In embodiments, the system includes an evaporating unit positioned within an aircraft galley. In another embodiment, the system includes a refrigeration and heat discharge unit positioned outside of the aircraft galley. In another embodiment, the system includes a liquid refrigerant pipe configured to fluidically couple the evaporating unit and the refrigeration and heat discharge unit. In another embodiment, the system includes a vapor refrigerant pipe configured to fluidically couple the evaporating unit and the refrigeration and heat discharge unit.

A divided aircraft galley refrigeration system is disclosed. In embodiments, the system includes an evaporating unit positioned within an aircraft galley. In another embodiment, the system includes a refrigeration and heat discharge unit positioned outside of the aircraft galley. In another embodiment, the system includes a liquid refrigerant pipe configured to fluidically couple the evaporating unit and the refrigeration and heat discharge unit. In another embodiment, the system includes a vapor refrigerant pipe configured to fluidically couple the evaporating unit and the refrigeration and heat discharge unit.

An air-conditioning system that performs a refrigeration cycle in a refrigerant circuit includes: an outdoor unit; a plurality of indoor units; a refrigerant connection pipe that connects the outdoor unit and the indoor units; and a first control valve disposed in the refrigerant connection pipe and that blocks a flow of refrigerant. The refrigerant connection pipe includes: a plurality of indoor-side pipes that each communicate with one of the indoor units; an outdoor-side pipe that communicates with two or more of the indoor-side pipes from an outdoor unit side; and a branch that connects the outdoor-side pipe and a group of two or more of the indoor-side pipes.

An air-conditioning system that performs a refrigeration cycle in a refrigerant circuit includes: an outdoor unit; a plurality of indoor units; a refrigerant connection pipe that connects the outdoor unit and the indoor units; and a first control valve disposed in the refrigerant connection pipe and that blocks a flow of refrigerant. The refrigerant connection pipe includes: a plurality of indoor-side pipes that each communicate with one of the indoor units; an outdoor-side pipe that communicates with two or more of the indoor-side pipes from an outdoor unit side; and a branch that connects the outdoor-side pipe and a group of two or more of the indoor-side pipes.

A refrigerant pipe constituting a refrigerant circuit of a refrigeration apparatus, includes: a pipe body made of stainless steel; and a first connecting tube made of copper or a copper alloy and that is configured to connect a first different refrigerant pipe to the refrigerant pipe. The first connecting tube is connected to an outer circumferential surface of a first end of the pipe body in a pipe axis direction of the pipe body. The first connecting tube overlaps with the pipe body in a pipe diameter direction in an entirety of the first connecting tube in the pipe axis direction.

When a refrigerant leakage sensor detects a leakage of refrigerant from a refrigeration cycle apparatus having an indoor unit and an outdoor unit, a refrigerant recovery operation is started. In the refrigerant recovery operation, refrigerant is recovered in an accumulator and afterward a pump down operation is performed. In recovery of refrigerant in the accumulator, refrigerant in a liquid phase is accumulated in the accumulator as a result of circulation of refrigerant by operating a compressor in the state where a liquid shut-off valve and a gas shut-off valve are opened. After recovery of refrigerant in the accumulator is ended, the refrigerant in a liquid phase is accumulated in an outdoor heat exchanger by the pump down operation for operating the compressor in the state where the liquid shut-off valve is closed.

When a refrigerant leakage sensor detects a leakage of refrigerant from a refrigeration cycle apparatus having an indoor unit and an outdoor unit, a refrigerant recovery operation is started. In the refrigerant recovery operation, refrigerant is recovered in an accumulator and afterward a pump down operation is performed. In recovery of refrigerant in the accumulator, refrigerant in a liquid phase is accumulated in the accumulator as a result of circulation of refrigerant by operating a compressor in the state where a liquid shut-off valve and a gas shut-off valve are opened. After recovery of refrigerant in the accumulator is ended, the refrigerant in a liquid phase is accumulated in an outdoor heat exchanger by the pump down operation for operating the compressor in the state where the liquid shut-off valve is closed.

A method for operating and controlling a vapor-compression cycle includes providing a system comprising an evaporator with a fan, a compressor, a condenser with a fan, an integrated expander, and a flash tank device with a vapor/liquid two-phase inlet and two outlets wherein a first outlet is a vapor outlet and a second outlet is a liquid outlet, and a metering valve; bringing a vapor-compression cycle up to steady-state at a fixed operating condition; opening the metering valve until the desired compressor suction superheat is achieved; and maintaining the desired degree of superheat by selectively increasing and decreasing superheat by reducing and increasing metering valve flow rate respectively.

When an ejector having a variable nozzle and a variable throttle mechanism are integrated together as an ejector module, a nozzle-side central axis CL1 and a decompression-side driving mechanism have a twisted positional relationship, if the nozzle-side central axis CL1 is defined as a central axis of a nozzle-side driving mechanism in a displacement direction in which the nozzle-side driving mechanism of the ejector having the variable nozzle displaces a needle valve, and the decompression-side central axis CL2 is defined as a central axis of a decompression-side driving mechanism in a displacement direction in which the decompression-side driving mechanism of the variable throttle mechanism displaces a throttle valve. When viewed from the central axis direction of one of the nozzle-side central axis CL1 and the decompression-side central axis CL2, a driving portion corresponding to the one central axis is disposed to overlap with the other central axis.