Disclosed is a valve, an expansion valve and their stepping control methods. The valve includes a valve body, a limiting unit, and a heating unit installed in the limiting unit. The valve body has an actuation space, and a first through hole and a second through hole communicated with the actuation space, and the actuation space further contains a valve seat disposed between the first and second through holes, and the limiting unit is installed in the actuation space, and a variable spacing is defined between the limiting unit and the valve seat. When the variable spacing is reduced, the heating unit heats up the interior of the limiting unit for heating to prevent ice buildups, so as to maintain a flowing state of the variable spacing.

Disclosed is a valve, an expansion valve and their stepping control methods. The valve includes a valve body, a limiting unit, and a heating unit installed in the limiting unit. The valve body has an actuation space, and a first through hole and a second through hole communicated with the actuation space, and the actuation space further contains a valve seat disposed between the first and second through holes, and the limiting unit is installed in the actuation space, and a variable spacing is defined between the limiting unit and the valve seat. When the variable spacing is reduced, the heating unit heats up the interior of the limiting unit for heating to prevent ice buildups, so as to maintain a flowing state of the variable spacing.

A water electrolysis system includes a water electrolysis device; a water circulation circuit section including a water circulation pump; an antifreeze circulation circuit section including an antifreeze circulation pump; and a heat exchanger configured to perform heat exchange between the water circulation circuit section and the antifreeze circulation circuit section. Before water electrolysis is started by the water electrolysis device, a control device of the water electrolysis system circulates water by driving the water circulation pump and sets the antifreeze circulation pump to an operationally stopped state.

A compressor includes a casing and a metallic coating. The casing includes a low-pressure casing part covering a low-pressure space and a high-pressure casing part covering a high-pressure space. The metallic coating is formed at least on a part of an outer surface of the casing. The metallic coating includes a low-pressure part coating formed in the low-pressure casing part, a high-pressure part coating formed in the high-pressure casing part, and a welded part coating formed in a welded part. At least either the average thickness of the low-pressure part coating or the average thickness of the welded part coating is greater than the average thickness of the high-pressure part coating.

A compressor includes a housing, and an anticorrosive coating covering a surface of the housing. The anticorrosive coating includes a base layer applied on the surface of the housing, and a surface layer applied on the base layer. Both the base layer and the surface layer are organic coatings. Thus, the housing of the compressor is effectively separated from the external environment by means of the two organic coatings, so as to ensure that the compressor is not corroded; moreover, the anticorrosive coating does not contain a metal coating, thereby preventing the problem of the compressor being severely corroded due to an exposed metal coating.

A heat cycle system is a heat cycle system (1) using a working medium containing hydrofluoroolefin (HFO) that has a double bond in a molecule structure, the heat cycle system (1) having a compressor (10), a high-pressure side heat exchanger (12), a low-pressure side heat exchanger (14), an expansion mechanism (13), and an acid detection means (40) which is disposed in a discharge pipe (21) connecting the compressor (10) and the high-pressure side heat exchanger (12) and which detects acid generated by decomposition of the working medium in a heat cycle.

An evaporator includes: an evaporator case that defines a food storage space therein; a cooling tube located at the evaporator case and filled with refrigerant; a foil heater attached to at least one surface of the evaporator case and configured to contact the evaporator case and to generate heat such that heat for defrosting is transferred to the evaporator case. A defrosting time is reduced in comparison to that of conventional natural defrosting, such that the freshness of food can be maintained, and the cooling efficiency, having been reduced by frost, is increased such that power consumption can be reduced. The foil heater is attached to a conventional roll-bond type evaporator case, and the present invention has an advantageous effect of facilitating the maintenance of the foil heater because of a structure in which the foil heater is attached to the evaporator case.

A method of preventing evaporator coil freeze in a heating, ventilation and air conditioning (HVAC) system is performed by a controller in the HVAC system. The method includes determining a reference saturated suction temperature (SST) via a sensor disposed in relation to an evaporator coil in the HVAC system. The method also includes determining whether the reference SST is below a minimum SST threshold. The method also includes, responsive to a determination that the reference SST is below the minimum SST threshold, increasing a discharge air temperature (DAT) setpoint.

An air conditioner 1 is disclosed as an air conditioner configured to condition air by connecting an indoor unit 2 including a first heat exchanger 11 in which a refrigerant exchanging heat with room air flows to an outdoor unit 3 including a second heat exchanger 24 in which a refrigerant exchanging heat with outdoor air flows. The first heat exchanger 11 includes a first heat transfer tube 11a1 made of aluminum or aluminum alloy, and the second heat exchanger 24 includes a second heat transfer tube 24a made of aluminum or aluminum alloy. A first sacrificial layer 45a is formed on an outer circumferential surface of the first heat transfer tube 11a1, and a second sacrificial layer 35 is formed on an outer circumferential surface of the second heat transfer tube 24a. The maximum thickness to of the second sacrificial layer 35 is larger than the sacrificial layer ti1 of the first sacrificial layer 45a. This suppresses corrosion of the heat transfer tube of the outdoor unit.

A vehicle air conditioner includes a cooling heat exchanger arranged in a casing, a compressor control portion which controls a compressor such that a cooling temperature at the cooling heat exchanger approaches a target cooling temperature, and a dryness determination portion which determines whether an outer surface of the cooing heat exchanger is dry or not based on a humidity in the casing. A target temperature determination portion determines the target cooling temperature to be any one of target temperatures including a first target temperature that is lower than a dew-point temperature in the casing, when the dryness determination portion determines that the cooling heat exchanger is not dry. The target temperature determination portion determines the target cooling temperature to be any one of the target temperatures other than the first target temperature, when the dryness determination portion determines that the cooling heat exchanger is dry.