A refrigerant control system includes: a charge module configured to determine an amount of refrigerant that is present within a refrigeration system of a building; a leak module configured to diagnose that a leak is present in the refrigeration system based on the amount of refrigerant; and at least one module configured to take at least one remedial action in response to the diagnosis that the leak is present in the refrigeration system.

A refrigeration system has a main refrigeration circuit including a compression stage, a condensing stage, and an evaporation stage, a refrigerant circulating between the compression stage, the condensing stage and the evaporation stage in a refrigeration cycle. An integrated transfer system is in closeable and openable fluid communication with the main refrigeration circuit, the transfer system including a receiver. Valves are operable to selectively open the fluid communication between the main refrigeration circuit and the transfer system. A motive force source displaces refrigerant from the main refrigeration circuit to the transfer system.

An outdoor expansion valve is provided for a liquid side pipe of an outdoor circuit. The outdoor circuit is provided with a liquid side bypass pipe that allows the liquid side pipe to communicate with a suction side of a compressor. Receiving a signal indicating that a refrigerant has leaked from an indoor circuit, an outdoor controller executes a refrigerant recovery control operation of operating the compressor with a liquid side control valve closed, and executes a valve control operation of opening a liquid side bypass valve of the liquid side bypass pipe in the refrigerant recovery control operation. As a result, the refrigerant can be recovered from an utilization-side circuit to a heat-source-side circuit while avoiding damage to the compressor, and the amount of refrigerant leaking from the utilization-side circuit can be reduced.

A stopper includes a filtering unit that is housed in an interior of a liquid receiver main body and through which a refrigerant passes, a fixed portion that includes on an outer peripheral face thereof a screw portion that is screwed into an inner peripheral face of the liquid receiver main body, a sealing member that is brought into contact with the inner peripheral face of the liquid receiver main body, thereby preventing a leakage of a refrigerant to the fixed portion from between the filtering unit and the liquid receiver main body, and a movable connection portion that is provided between the filtering unit and the fixed portion and links the filtering unit to the fixed portion in such a way that the filtering unit is not caused to follow a rotation of the fixed portion, and in such a way that the filtering unit is caused to follow an axial direction movement of the fixed portion.

A valve includes a movable valve member movable relative to a valve port between a closed position in which fluid flow through the valve port is inhibited and an open position in which fluid flow through the valve port is permitted. A valve seat is coupled to the movable valve member. The valve seat is configured to seat against and seal the valve port when the movable valve member is in the closed position and to be spaced apart from the valve port when the valve member is in the open position. A sealing member is disposed within a cavity behind the valve seat.

Provided is a refrigeration apparatus with improved safety. A refrigeration apparatus includes: a compressor; a heat source-side expansion valve to be controlled to have a minimum opening degree and brought into a closed state in which the heat source-side expansion valve maximizes prevention of a flow of a refrigerant toward a usage-side refrigerant circuit; a fusible plug; a controller; and a refrigerant leak detector configured to detect a refrigerant leak at the usage-side refrigerant circuit. The fusible plug is disposed in a refrigerant circuit, and is brought into an open state to allow the refrigerant circuit to communicate with an external space. When the refrigerant leak detector detects a refrigerant leak at the usage-side refrigerant circuit, the controller performs refrigerant leak first control to bring the heat source-side expansion valve into the closed state, and performs refrigerant leak second control to bring the fusible plug into the open state.

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.

There is provided a refrigerant charging method in which a foreign material and moisture are avoided from entering a heat source unit until a refrigeration cycle apparatus is configured. The refrigerant charging method is a method of charging a refrigerant to a refrigerant circuit in which a refrigeration cycle is to be performed by a circulating refrigerant, the refrigerant circuit being configured by connecting a second heat source unit and a utilization unit to each other. The refrigerant charging method includes charging a first refrigerant to the second heat source unit before connecting the second heat source unit to the utilization unit to configure the refrigerant circuit, and connecting the second heat source unit to the utilization unit and charging a second refrigerant that differs from the first refrigerant to the refrigerant circuit to obtain the circulating refrigerant that includes the second refrigerant and the first refrigerant that is charged in the second heat source unit.

A refrigerant control system includes: a charge module configured to determine an amount of refrigerant that is present within a refrigeration system of a building; a leak module configured to diagnose that a leak is present in the refrigeration system based on the amount of refrigerant; and at least one module configured to take at least one remedial action in response to the diagnosis that the leak is present in the refrigeration system.

A pulse tube refrigerating machine enables maintenance of an orifice while circulation of refrigerant gas within individual components is allowed, thus reducing the time required for maintenance. A compressor delivers a refrigerant gas having a high pressure and sucks the refrigerant gas having a low pressure. A cold head including a regenerator tube through which the refrigerant gas circulates and a pulse tube is connected to a housing. The flow of the refrigerant gas is controlled by one or more orifices, which are disposed outside the housing. The compressor, the housing, and the orifices are coupled via tubing. A coupling unit is disposed at both ends of at least one of the orifices. The coupling unit has a structure such that it can be split while the refrigerant gas is retained within the tubing. When the coupling unit is split, a detachable unit portion including the orifice is isolated.