A refrigeration system includes a valve and a controller. The valve is configured to control the flow of refrigerant into an evaporator, the refrigerant having an associated liquid setting comprising a temperature and a pressure at which the refrigerant flows through the valve. The controller is operable to adjust the liquid setting, the adjusted liquid setting comprising a temperature and a pressure selected to improve energy efficiency under conditions currently being experienced by the refrigeration system, wherein the controller is operable to adjust the temperature and the pressure simultaneously such that the adjustment does not interfere with operation of the valve.

A refrigerator and a method for controlling a refrigerator are provided. The method may include driving a refrigerating cycle including a first evaporator and a second evaporator by activating at least one compressor, supplying refrigerant to the first and second evaporators by controlling a flow adjuster, recognizing whether the refrigerant is unequally introduced into the first or second evaporator, by sensing a temperature of the first or second evaporator through at least one temperature sensor, reducing supply of the refrigerant to the first or second evaporator into which the refrigerant is unequally introduced, by adjusting the flow adjuster, storing information about an operation time of the flow adjuster, recognizing whether the at least one temperature sensor has malfunctioned, and determining an operation time of the flow adjuster according to whether the at least one temperature sensor has malfunctioned.

A heat pump system includes a heat source unit having a variable-capacity compressor and a heat-source-side heat exchanger that functions as an evaporator for a refrigerant, and a plurality of usage units connected to the heat source unit and having usage-side heat exchangers that function as radiators for the refrigerant. The operating capacity of the compressor is controlled to bring the discharge pressure of the compressor, or a state quantity equivalent to the discharge pressure, to a first target value. The first target value is determined based on an equivalent target value equivalent to a usage temperature required in individual usage units.

A heat pump system for a vehicle delays the change of the direction of a directional valve for a given period of time and then conducts the change of the direction of the directional valve, upon receiving the mode change signal between an air conditioner mode and a heat pump mode, thus preventing the generation of the noise and vibration caused by the differential pressure of a refrigerant.

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.

An air conditioning apparatus includes a first refrigerant circuit enclosing a first refrigerant, and a second refrigerant circuit enclosing a second refrigerant. The first refrigerant circuit includes a compressor configured to compress the first refrigerant, an outdoor heat exchanger, an expansion device, and a first flow path through which the first refrigerant passes in an intermediate heat exchanger configured to exchange heat between the first refrigerant and the second refrigerant. The second refrigerant circuit includes a pump configured to increase a pressure of the second refrigerant and transfer the second refrigerant, a second flow path through which the second refrigerant passes in the intermediate heat exchanger, and an indoor heat exchanger. At least one of the first refrigerant and the second refrigerant has a global warming potential lower than that of R32, and the second refrigerant has a lower flammable limit concentration higher than that of the first refrigerant.

A refrigeration system includes a refrigeration circuit and a coolant circuit separate from the refrigeration circuit. The refrigerant circuit includes a gas cooler/condenser, a receiver, and an evaporator. The coolant circuit includes a heat exchanger configured to transfer heat from a refrigerant circulating within the refrigeration circuit into a coolant circulating within the coolant circuit, a heat sink configured to remove heat from the coolant circulating within the coolant circuit, and a magnetocaloric conditioning unit configured to transfer heat from the coolant within a first fluid conduit of the coolant circuit into the coolant within a second fluid conduit of the coolant circuit. The first fluid conduit connects an outlet of the heat exchanger to an inlet of the heat sink, whereas the second fluid conduit connects an outlet of the heat sink to an inlet of the heat exchanger.

An air conditioning apparatus includes, a first heat exchanger, a second heat exchanger configured to exchange heat between a first heat medium and a second heat medium, flow rate control valves, and a pump. In a heating mode, a controller is configured to open the flow rate control valve corresponding to a heat exchanger, of the third heat exchangers, to which a request for air conditioning has been made, and to close the flow rate control valve(s) corresponding to a heat exchanger(s), of the third heat exchangers, to which the request for air conditioning has not been made. In a defrosting mode, when a temperature of the second heat medium is lower than a first determination temperature, the controller is configured to open at least one of the flow rate control valve(s) corresponding to the heat exchanger(s) to which the request for air conditioning has not been made.

A cooling system uses P-traps to address the oil return issues that result from a vertical separation between the compressor and the high side heat exchanger. Generally, the vertical piping that carries the refrigerant from the compressor to the high side heat exchanger includes P-traps installed at various heights to capture oil in the refrigerant and to prevent that oil from flowing back to the compressor. As oil collects in the P-traps, the refrigerant begins to push the oil upwards until the oil reaches the high side heat exchanger. Multiple piping of different sizes may be used depending on a discharge pressure of the compressor. When the discharge pressure is higher, a larger piping may be used direct the oil and refrigerant to the high side heat exchanger.

A cooling device includes a circulation system configured to circulate a refrigerant in a condenser so as to return the refrigerant to the condenser via a pump, a heater, a throttle valve, and a vaporizer; and a cooling system that includes a heat exchanger arranged in the condenser. The condenser includes a first portion where the refrigerant is present in a liquid state and a second portion where the refrigerant is present in a gas state, and at least a portion of the heat exchanger is arranged in the second portion.