According to one embodiment, a heat transport apparatus includes an evaporator, a cooling unit, a channel structure, and a heating mechanism. The evaporator vaporizes a refrigerant by heat generated by a heat-generating element. The cooling unit is provided above the evaporator and cools and condenses the refrigerant vaporized in the evaporator. The channel structure constitutes a channel through which the refrigerant circulates between the evaporator and the cooling unit. The heating mechanism heats the cooling unit and suppresses solidification of the refrigerant at the cooling unit.

A control method and control device for a heat pump-type double-circulation hot-air drying system, relating to a device for supplying or controlling air or gas for drying solid materials or products, and in particular to a control method and control device for a heat pump-type hot-air drying system. The method comprises: configuring a temperature control parameter, and saving a preset temperature control curve parameter; detecting and monitoring an outlet air temperature, and the temperature and humidity of a drying room; dynamically adjusting a set temperature according to a preset temperature control curve; and selecting, according to a current set temperature, a double-circulation dynamic operation mode of a system. The control device uses a micro-processor to realize program control. By building an inner circulation loop for large-volume air circulation, the latent heat of condensation in a refrigerant is fully absorbed, to improve the basic air temperature.

A pressure switch includes an airtight metallic pressure vessel. A contact mechanism is normally in a closed state and assumes an open state when a pressing force acts thereon. An airtight terminal, provided through an end surface section of the pressure vessel, is connected to the contact mechanism. A metallic first diaphragm is secured to a surface section at one end of the pressure vessel, is moved by a first moving pressure, and is reset by a reset pressure that is lower than the first moving pressure. A first plunger causes the contact mechanism to switch the open state. A metallic second diaphragm is secured to pressure vessel, is moved by a second moving pressure that is higher than the first moving pressure, and is not reset under at least an atmospheric pressure. A second plunger causes the contact mechanism to switch to the open state.

A cooling system includes a heat exchange unit; a supply line configured to send a coolant to the heat exchange unit; a drain line configured to send the coolant drained from the heat exchange unit; a first to a n.sup.th gas-liquid separating units connected in series to a gas line in which a gas of the coolant flows; a first to a n.sup.th cooling lines extended via the first to the n.sup.th gas-liquid separating units, respectively. Both ends of the first cooling line are connected to a cooling device. The second to the n.sup.th cooling lines are provided between the drain line and a first to a (n1).sup.th liquid lines via the second to the n.sup.th gas-liquid separating units, respectively. The first to the n.sup.th gas-liquid separating units are respectively connected to liquid lines, and the liquid lines communicate with the supply line connected to the heat exchange unit.

An air conditioning apparatus is equipped with an indoor fan, an indoor heat exchanger, and a control unit. The indoor heat exchanger generates conditioned air by exchanging heat between refrigerant and room air. The control unit sets operating modes. The control unit controls the rotational speed of the indoor fan. More specifically, in a case where the operating mode has been switched from one to the other of a normal heating mode and a hot air mode in which the conditioned air higher in temperature than in the normal heating mode is generated, the control unit lowers the rotational speed at a second rate that is slower than a first rate which is a rate of decrease in the rotational speed in a case where the operating mode is set to the normal heating mode.

A refrigeration system is described having a circuit around which a refrigerant circulates. The circuit includes a compressor, a metering device, a first heat exchanger for exchanging heat between the refrigerant and a medium, and a second heat exchanger for exchanging heat between the refrigerant and a thermal store. The refrigeration system is operable in a first mode and a second mode. In the first mode, the metering device has a first restriction such that the medium is cooled at the first heat exchanger and the thermal store is heated at the second heat exchanger. In the second mode, the metering device has a second, less restrictive restriction or is bypassed such that the medium is heated at the first heat exchanger and the thermal store is cooled at the second heat exchanger.

A method of operating a compressor includes obtaining a harmonic series representation of speed variation as the rotor rotates through each revolution. The method includes regulating an electric motor to compensate for or cancel out the periodic speed variation. Specifically, the method includes calculating an electromagnetic torque using a torque control input model based on the speed error and the harmonic series representation of the speed error. The operation of the electric motor is then adjusted such that the electromagnetic torque applied by the motor cancels out the speed variation such that noise and vibrations are minimized.

According to one embodiment, a heat transport apparatus includes an evaporator, a cooling unit, a channel structure, and a heating mechanism. The evaporator vaporizes a refrigerant by heat generated by a heat-generating element. The cooling unit is provided above the evaporator and cools and condenses the refrigerant vaporized in the evaporator. The channel structure constitutes a channel through which the refrigerant circulates between the evaporator and the cooling unit. The heating mechanism heats the cooling unit and suppresses solidification of the refrigerant at the cooling unit.

A refrigerating machine which is equipped with: a turbocompressor 2 that compresses a refrigerant; a condenser 3 that condenses the refrigerant compressed by the turbocompressor 2; an intermediate cooler 4 that is a plate heat exchanger which performs heat exchange between the liquid refrigerant introduced from the condenser 3 and the two-phase refrigerant obtained by expanding, with a sub-expansion valve 13, part of the liquid refrigerant introduced from the condenser 3; a main expansion valve 5 that expands the liquid refrigerant introduced from the intermediate cooler 4; and an evaporator 7 that evaporates the refrigerant introduced from the main expansion valve 5. The plate heat exchanger includes 80 or more laminated plates, the width of which is 100-400 mm and the height of which is 300-1000 mm.

An expander generates cold by expanding a refrigerant gas in a cryogenic refrigerator. A compressor compresses the refrigerant gas returning from the expander. Pipes are connected to the expander and the compressor and circulate the refrigerant gas between the expander and the compressor. A determiner determines whether or not a change cycle of the pressure of the refrigerant gas flowing in the pipes is in a predetermined range. The determiner may determine whether or not the change cycle of the pressure of a low-pressure pipe in which a low-pressure refrigerant gas flows toward the compressor from the expander is in a predetermined range.