A dedicated outside air-conditioning system (DOAS) that may automatically generate variable subcooling refrigerant delivered to the evaporator; and modulate hot discharge gas to reduce the relative humidity of the discharge air from the DOAS. The DOAS may include fluid control valves configured to regulate delivery of the refrigerant in order to seamlessly flex between maximum latent capacity (minimum discharge dewpoint) and maximum sensible capacity (minimum leaving air discharge dry bulb temperature) to match load and/or ventilation air requirements.

Disclosed is a screw compressor (100), comprising a screw compressor housing (101), a discharge cavity (113), at least one silencing channel, and at least one adjustment piston, wherein the discharge cavity (113) is defined by at least one part of the screw compressor housing (101); the at least one part of the screw compressor housing (101) defining the discharge cavity (113) forms a wall of the discharge cavity (113); at least one hole is provided in the wall of the discharge cavity (113); the at least one adjustment piston can be inserted into the at least one hole and move therein; the at least one silencing channel is formed by the at least one hole and the at least one adjustment piston, and the at least one silencing channel is in fluid communication with the discharge cavity (113); and the position of the at least one adjustment piston in the at least one hole determines the silencing length of the at least one silencing channel.

The propagation of a disproportionation reaction of a refrigerant is suppressed. Disclosed is a method that uses a composition as a refrigerant in a refrigerant circuit, in which the composition includes one or more compounds selected from the group consisting of ethylene-based fluoroolefins, 2,3,3,3-tetrafluoropropene, and 1,3,3,3-tetrafluoropropene, and the refrigerant circuit includes a compressor, a four-way switching valve, and a first refrigerant pipe connecting the compressor and the four-way switching valve, the first refrigerant pipe having a pipe diameter less than or equal to ⅜ inch or a length greater than or equal to 5 cm.

A method of cooling a motor coupled to a compressor of a chiller includes adjusting a position of a motor cooling valve located fluidly between the motor and a refrigerant source, using a motor temperature control system coupled to the motor cooling valve to regulate an amount of refrigerant introduced into the motor from the condenser according to a temperature control scheme performed as a function of a monitored temperature in the motor, a first temperature threshold, and a second temperature threshold lower than the first temperature threshold. The temperature control scheme includes a motor cooling control process that adjusts the position of the motor cooling valve based on a stator winding temperature set point relating to stator windings of the motor. A proportionally limited close command override associated with a first temperature range above the second temperature threshold proportionally limits a close command provided to the motor cooling valve.

A refrigeration cycle apparatus includes a compressor, a first heat exchanger, a decompressing device, a second heat exchanger, a first switching valve, a second switching valve, and a controller. The first switching valve is switched to one of a first state and a second state. The second switching valve is switched to one of a third state, a fourth state, and a fifth state. When switching to a second cooling operation to bring the first and second switching valves into the second and fourth states respectively, is requested during a first cooling operation to bring the first and second switching valves into the first and third states, respectively, the controller performs a first switching operation to bring the first switching valve into the second state and bring the second switching valve into the fifth state, and thereafter switches the first switching operation to the second cooling operation.

Thermal management systems include an open circuit refrigeration system featuring a first receiver configured to store a gas, a second receiver configured to store a liquid refrigerant fluid, an evaporator configured to extract heat from a heat load that contacts the evaporator, and an exhaust line, where the first receiver, the second receiver, the evaporator, and the exhaust line are connected to provide a refrigerant fluid flow path.

An air flow controller for an air cleaner and an air cleaner are provided. The air flow controller may include a fan, and a housing, the fan being provided in the housing and the housing being movable from an initial horizontal position in which the air flow controller directs air flow in a vertical direction to an inclined position in which the air flow controller directs air flow in a diagonal direction.

A compressor unit includes a first case, a compressor, a connecting port, and a shutoff valve. The connecting port includes a first connecting port and a second connecting port. The shutoff valve includes a first shutoff valve and a second shutoff valve. A heat source heat exchanger is accommodated in a second case. A utilization heat exchanger is accommodated in a third case. The compressor unit is disposed inside a building. The first connecting port is connected to the heat source heat exchanger via a first connection piping. The second connecting port is connected to the utilization heat exchanger via a second connection piping. The first shutoff valve shuts off flow of a refrigerant between the first connecting port and the heat source heat exchanger. The second shutoff valve shuts off flow of the refrigerant between the second connecting port and the utilization heat exchanger.

A cooling system includes a coolant transmitter that transmits coolant at a pressure greater than atmospheric pressure. The cooling system also includes an evaporation vessel at atmospheric pressure. The evaporation vessel can contain an amount of coolant at the boiling point of the coolant. The cooling system also includes a pressure reducer fluidically coupled to the coolant transmitter and the evaporation vessel. The pressure reducer can include an orifice. The cooling system is configured such that heat is transferred from the coolant in the coolant transmitter to the coolant contained in the evaporation vessel. An exit stream conduit can fluidically couple the coolant transmitter and the pressure reducer, with the exit stream conduit diverting a portion of the coolant from the coolant transmitter to the evaporation vessel.

An electronic thermostat control system may include a control duty determination portion outputting PWM duty signal for controlling the coolant temperature according to a coolant temperature, a rising rate of the coolant temperature, an engine speed, a load and a vehicle speed, a driving portion applying a time condition to the PWM duty signal output by the control duty determination portion for controlling outputting interval, and a fault diagnosis portion diagnosing operations of the electronic thermostat by analyzing the signals output by the driving portion and changes of the coolant temperature.