The present invention relates to an air conditioner. A first invention according to the present embodiment is an air conditioner which has a refrigeration capacity of 16 kW to 28 kW, inclusive, and uses a mixed refrigerant R134a as a refrigerant, and in which a refrigerant pipe includes a ductile stainless steel pipe having 1% or less of a delta-ferrite matrix structure with respect to the grain size area thereof.

A method of controlling an HVAC circuit, comprises allowing refrigerant to circulate within the HVAC circuit, wherein the HVAC circuit comprises an evaporator coil, a condenser coil, at least one fan configured to provide airflow to the condenser coil, at least one expansion valve, and at least one compressor. The method continues by receiving a temperature measurement and determining based on the temperature measurement, a minimum fan speed configured to avoid pressure spikes within the condenser coil. The method concludes by sending a signal to the at the least one fan to direct the at least one fan to spin at a rate greater than or equal to the minimum fan speed when the measured temperature is less than a predetermined temperature, wherein, when the refrigerant circulates through the condenser coil, the minimum fan speed is greater than zero rotations per minute.

Technologies are described herein for cooling systems. In some aspects, a cooling system is configured to enter into a storage configuration or a wintenzation configuration. In the wintenzation configuration, refrigerant used in the cooling system is stored in an adsorbent in an adsorbent chamber.

A method of mitigating liquid-refrigerant migration includes comparing a requested compressor speed of a variable-speed compressor to a pre-defined threshold and, responsive to a determination that the requested compressor speed is greater than the pre-defined threshold, operating the variable-speed compressor at a first compressor speed that is less than the requested compressor speed.

A centrifugal compressor for a chiller system includes a casing having an inlet portion and an outlet portion, a recirculation structure including a recirculation path and a recirculation discharge cavity, an impeller disposed downstream of the recirculation discharge cavity, a plurality of recirculation discharge guide vanes disposed to surround the recirculation discharge cavity, and a diffuser disposed in the outlet portion downstream of the impeller. The recirculation structure is configured to impart a swirl to a flow of refrigerant into the inlet portion. The recirculation path supplies the refrigerant from the diffuser to the recirculation discharge cavity. The recirculation path includes a recirculation pipe that introduces the refrigerant toward the plurality of recirculation discharge guide vanes. An annular groove is disposed between the recirculation pipe and the plurality of recirculation discharge guide vanes. An annular plate is disposed between the annular groove and the recirculation discharge cavity.

A cooling system comprising a cooling circuit connecting a heat exchanger and a heat load. The cooling system comprising a first velocity fuse upstream of the heat exchanger or heat load and a second velocity fuse or valve downstream of the heat exchanger or heat load. The heat exchanger or heat load is dynamically isolated from the rest of the cooling system by the first velocity fuse or the second velocity fuse in response to a velocity of a flow of cooling fluid exceeding a respective velocity setting of the first velocity fuse or the second velocity fuse.

A method of operating a chiller includes applying chiller operating data associated with the chiller as an input to one or more machine learning models, generating a boundary for a controllable chiller variable based on an output of the one or more machine learning models, and affecting operation of the chiller based on the boundary.

An improved expansion valve is provided, which has a simple configuration and with which noise can be reduced. An expansion valve includes a valve main body having a valve chamber and a valve seat, a valve body configured to prevent passage of a fluid by being seated on the valve seat and allow passage of the fluid by separating from the valve seat, a coil spring configured to urge the valve body toward the valve seat, and an actuation rod configured to press the valve body toward a direction separating from the valve seat against an urging force applied from the coil spring, wherein the valve chamber includes a cylindrical inner wall being connected to the valve seat, the valve body includes a contact portion configured to be seated on the valve seat and a body portion having a tubular shape facing the inner wall, and the body portion includes connecting surfaces that are slidably in contact with the inner wall and plane surfaces that have a gap provided between the inner wall.

A refrigeration apparatus includes a refrigerant circuit including: a compressor, a radiator, an expansion mechanism, and an evaporator. The refrigerant circuit encloses a refrigerant that contains a fluorinated hydrocarbon that causes a disproportionation reaction. The refrigerant circuit further includes: a discharged refrigerant recovery receiver that is connected to a path between a discharge side of the compressor and a gas side of the radiator through a discharged refrigerant branch pipe; and a discharged refrigerant relief mechanism that is disposed in the discharged refrigerant branch pipe and that connects the discharge side of the compressor with the discharged refrigerant recovery receiver when the refrigerant on the discharge side of the compressor satisfies a predetermined condition. The predetermined condition includes at least one of a first condition under which the refrigerant does not yet cause the disproportionation reaction and a second condition under which the refrigerant causes the disproportionation reaction.

Provided is an air conditioning apparatus. The air conditioning apparatus includes a heat exchanger in which the refrigerant and the water are heat-exchanged with each other, a high-pressure guide tube extending from a high-pressure gas tube of an outdoor unit so as to be connected to one side of the heat exchanger, a low-pressure guide tube extending from a low-pressure gas tube of the outdoor unit so as to be combined with the high-pressure guide tube, a liquid guide tube extending from a liquid tube of the outdoor unit so as to be connected to the other side of the heat exchanger, a bypass tube configured to connect a bypass branch point of the high-pressure gas tube to a bypass combination point of the liquid guide tube to bypass a high-pressure refrigerant existing in the high-pressure tube to the liquid guide tube, and a bypass valve installed in the bypass tube.