An electronic expansion valve includes a valve seat assembly, a first pipe connecting portion, and a second pipe connecting portion. The valve seat assembly includes an outer wall portion, a valve port portion having a valve port, a first valve seat cavity, and a second valve seat cavity. The first valve seat cavity is located above the valve port portion. The second valve seat cavity is located below the valve port portion. The valve port is capable of communicating with the first valve seat cavity and the second valve seat cavity. The first pipe connecting portion is fixedly connected to the outer wall portion located above the valve port portion. The second pipe connecting portion is fixedly connected to the outer wall portion located below the valve port portion. The inner diameter of the second valve seat cavity is greater than the inner diameter of the second pipe connecting portion.

A method of forming a sound attenuator around a compressor of an air conditioning system includes covering the compressor with a flexible protective cover and depositing a plurality of materials proximate an outer surface of the flexible protective cover such that at least some of the plurality of materials can chemically react to create a self-forming foam that abuts at least some of the flexible protective cover to thereby create the sound-attenuating structure around the compressor.

An oil separator and an air conditioning system provided with the oil separator are disclosed by the present disclosure. The oil separator comprises: an inlet (20) configured to receive a refrigerant; a duct (10) through which the refrigerant flows, the duct having a circumferential wall and comprising: a first section comprising a first muffler adjacent to the inlet, the first muffler (60) comprising a chamber (11) defined by a first wall (13) of the first section and designed to have a length dimension (L) in a length direction of the duct and a depth dimension (H) intersecting the length dimension; and a second section downstream of the first section, a second wall (23) of the second section being provided with a second muffler (70); and an oil separation assembly (80,90) through which the refrigerant passing through the duct passes. The present disclosure has a simple and reliable structure and is easy to implement.

A heat pump apparatus includes: a compression mechanism that compresses a refrigerant; a motor that drives the compression mechanism; an inverter that applies a voltage to the motor; and an inverter control unit that generates a drive signal for driving the inverter, based on a carrier signal, in which the inverter control unit periodically changes a carrier frequency of the carrier signal in a heating operation mode in which the refrigerant is heated, and generates the drive signal such that a period of time during which a voltage represented as a real vector is applied to the motor is kept constant regardless of the changed carrier frequency.

An air conditioning system capable of reducing noise incidental to gas-liquid two-phase transfer is provided. The air conditioning system (100) performs a refrigeration cycle in a refrigerant circuit (RC) including an outdoor unit (10), a plurality of indoor units (40), and a liquid-side connection pipe (LC) connecting the outdoor unit (10) and the indoor units (40). The air conditioning system (100) includes a second outdoor control valve (17, electric valve) decompressing the refrigerant flowing in the refrigerant circuit (RC) in accordance with an opening degree, an operating-capacity variation detection portion (74, detection portion) detecting change of the number of operating units in accordance with device information, and a device control portion (75, control portion) controlling a state of the second outdoor control valve (17). The device control portion (75) executes first control (feed-forward control) when the change of the number of operating units is detected by the operating-capacity variation detection portion (74), and adjusts the opening degree of the second outdoor control valve (17) to suppress a rise of pressure of the refrigerant flowing into the operating unit.

According to one embodiment, there is provided a refrigeration system including detectors, each of which detects a phase indicative of a displacement of a displacer of each of cryogenic refrigerators; a processor that calculates an operation frequency of a motor of each of the cryogenic refrigerators, which is a frequency that suppresses oscillations or noises generated by reciprocating motions of the displacer of each of the cryogenic refrigerators, based on a detection result obtained by each of the detectors; and drivers, each of which drives the motor of each of the cryogenic refrigerators based on a calculation result obtained by the processor.

A cryocooler includes a second-stage cooling stage, a second cylinder which includes the second-stage cooling stage on a terminal of the second-stage cylinder, a second-stage displacer which includes a magnetic regenerator material and is accommodated in the second-stage cylinder so as to be able to reciprocate in the second-stage cylinder, and a tubular magnetic shield which is installed on the second-stage cooling stage and extends along the second-stage cylinder outside the second-stage cylinder. The magnetic shield is formed of a normal conductor and a product of an electrical conductivity in a temperature range of 10 K (Kelvin) or less and a thickness of the tubular magnetic shield is 60 MS (Mega-Siemens) to 1980 MS.

An air conditioning apparatus includes an outdoor device that is configured to circulate refrigerant and that includes a compressor and an outdoor heat exchanger, a plurality of indoor devices configured to circulate water, and a heat exchange device connecting the outdoor device with the indoor device. The heat exchange device includes a heat exchanger configured to exchange heat between the refrigerant and the water, and a switch device configured to control flow of refrigerant between the indoor devices and the heat exchanger.

Disclosed are an electronic expansion valve and a refrigeration system. The electronic expansion valve includes: a valve seat provided with an inlet, an outlet and a communication channel in communication with the inlet and the outlet; an actuator movably mounted in the valve seat, wherein the actuator is provided with a first position to block the communication channel and a second position to avoid the communication channel; and a driving mechanism connected with the actuator to drive the actuator to move between the first position and the second position, wherein the driving mechanism includes noise reduction members to reduce noise of the electronic expansion valve.

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.