An integrated sensor and service port for HVAC (heating, ventilating, and air conditioning) equipment or an HVAC system. The integrated sensor and service port may comprise an anti-blowback mechanism.

According to an embodiment of the present disclosure, a refrigerant pipe fitting, the fitting having a pipe shape with a hollow to connect a pipe, may include an out pipe opening which is opened at one end of the fitting and into which an out pipe is inserted; an inner pipe opening which is opened at the other end of the fitting and into which an inner pipe is inserted to be inserted into the out pipe inside the fitting; a pressing portion which is configured to form a part of an inner surface of the fitting and formed to have a narrower inner diameter as it extends toward the inner pipe opening to press and deform the out pipe to allow the out pipe to connect with the inner pipe in movement of the fitting; and a fastening portion which is formed on the inner surface of the fitting between the pressing portion and the out pipe opening to constrain an end of the out pipe to prevent the fitting from being separated.

As a shut-off valve inspection process for checking operation of a liquid side shut-off valve and a gas side shut-off valve, an air conditioning system operates a compressor in a cooling cycle state, performs opening and closing operation of the liquid side shut-off valve and the gas side shut-off valve, and determines whether the liquid side shut-off valve and the gas side shut-off valve properly operate on the basis of a temperature value detected by a temperature sensor provided in an indoor unit.

A refrigeration cycle apparatus includes a refrigerant circuit and a controller for controlling the refrigerant circuit. The refrigerant circuit includes a compressor, a condenser, a pressure-reducing device and an evaporator. Refrigerant circulating through the refrigerant circuit contains propane or propylene. The controller sets a degree of superheat of refrigerant at an entrance port of the compressor to be a value greater than or equal to 10 degrees.

A double acting alpha Stirling refrigerator includes a piston cylinder and a piston, the piston is provided in the piston cylinder. The piston is in a clearance fit with an inner wall of the piston cylinder. A closed cavity is formed inside the piston. A cross-shaped four-way pipe is provided in the cavity of the piston. A one-way air outlet valve and a one-way air inlet valve are further respectively provided on the four-way pipe in the cavity of the piston. An air outlet for connecting the cavity of the piston to the inner cavity of the piston cylinder is provided on the piston. A traction frame movable relative to the piston cylinder is provided outside the piston cylinder, and the movement of the piston is controlled by the movement of the traction frame.

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 refrigeration cycle apparatus includes a refrigerant circuit through which refrigerant is circulated, a heat exchanger unit that accommodates a heat exchanger of the refrigerant circuit and a fan, a temperature sensor disposed in an area of the refrigerant circuit adjacent to a brazed connection or in an area of the refrigerant circuit adjacent to a joint between refrigerant pipes, and a controller configured to determine the presence of refrigerant leakage based on a temperature detected by the temperature sensor. The temperature sensor is covered by a heat insulation material together with the brazed connection or the joint. The controller activates the fan upon determining that refrigerant leakage is present, and is triggered to deactivate the fan in response to the time variation of the temperature detected by the temperature sensor becoming positive.

A sealing material of the present invention is a sealing material for sealing a metal material, including 70 mass % to 100 mass % of glass powder including alkali silicate glass and 0 mass % to 30 mass % of ceramic powder, and having a linear thermal expansion coefficient in a temperature range of from 30 C. to 380 C. of more than 10010.sup.7/ C. and 17010.sup.7/ C. or less.

A refrigeration system comprising 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.

The invention relates to a method for low-temperature cooling/liquefaction of a working fluid, in particular a working fluid including helium or consisting of pure helium by means of a refrigerator/liquefier that includes a working circuit provided with a compressor station and a cold box. The refrigerator/liquefier subjects the working gas within the working circuit to a cycle that includes, in series: compressing the working fluid within the compressor station, cooling and decompressing the working fluid in the cold box, and heating the working fluid with a view to the return thereof to the compressor station. The compressor station includes one or more compression levels, each one using one or more compressors mounted on landings. The method is characterized in that the refrigerator includes a device for injecting a seal gas that is separate from the working fluid on at least one landing of the compressor(s) so as to form a gas seal that guides the working fluid leaks, coming from the working circuit, to an area for recirculating and returning the fluid into the working circuit.