Systems and methods for controlled subcooling of working fluid in a heating, ventilation, air conditioning and refrigeration (HVACR) system through a suction line heat exchanger are disclosed. The suction line heat exchanger may receive a first fluid flow travelling to a suction of the compressor in the HVACR system and second flow of working fluid that is travelling from a heat exchanger receiving the discharge of the compressor to an expansion device. Superheating of the first working fluid may be determined based on temperature measurements prior to and following the suction line heat exchanger. The superheating may be used to control the quantity of the second flow of working fluid introduced into the suction line heat exchanger, for example to maintain superheat that is below a threshold value. These systems may include chillers and heat pump systems, and methods may be applied to chillers or heat pump systems.

A refrigeration system includes a heat exchanger configured to place a cooling fluid in a heat exchange relationship with a working fluid, a free-cooling circuit having a pump configured to circulate the working fluid through the heat exchanger and a condenser, a flow control valve configured to control a flow rate of the working fluid to the condenser, a condenser bypass valve configured to control a flow rate of the working fluid that bypasses the condenser, and a controller configured to adjust a position of the flow control valve, a position of the condenser bypass valve, a speed of a fan of the condenser, a speed of the pump, and a temperature of a heater based on an ambient temperature, a temperature of the working fluid leaving the condenser, the position of the flow control valve, the position of the condenser bypass valve, or a combination thereof.

A mobile air conditioner, comprising: a first heat exchanger, having a first interface and a second interface for a refrigerant to enter and exit; a phase-change energy storage heat exchange device, including a second heat exchanger and a phase-change energy storage working medium, wherein the second heat exchanger and the phase-change energy storage working medium may exchange heat therebetween, and the second heat exchanger has a third interface and a fourth interface for the refrigerant to enter and exit; a first refrigerant pipeline, connected to the first interface and the third interface; and a second refrigerant pipeline, connected to the second interface and the fourth interface.

A temperature controller for a sorption system having an evaporator to produce a gas, a sorber containing a sorption material to sorb the gas during a sorption phase, a flow channel extending between the evaporator and sorber to provide a gas pathway connecting them, a valve to control the rate of gas flow in the flow channel, and a temperature sensor positioned to measure the temperature of an evaporator surface or the air adjacent thereto indicative of an evaporator surface temperature, and generate a temperature signal. The controller includes an inflatable member having first and second inflation states, and a control unit configured to evaluate the temperature signal and in response control the state of inflation of the inflatable member and thereby the operation of the valve to control the rate of gas flow between the evaporator and sorber through the gas pathway.

A refrigerant control system includes: a reversing valve including: a first inlet configured to receive refrigerant output from a condenser; a first outlet configured to output refrigerant to an inlet of an evaporator located inside of a building; a second inlet configured to receive refrigerant output from the evaporator; and a second outlet configured to output refrigerant to an inlet of a compressor that pumps refrigerant to the condenser; a reversing module configured to: selectively actuate the reversing valve to a first position such that: refrigerant flows directly from the second inlet to the second outlet; and refrigerant flows directly from the first inlet to the first outlet; and selectively actuate the reversing valve to a second position such that: refrigerant flows directly from the second inlet to the first outlet; and refrigerant flows directly from the first inlet to the second outlet.

A heat pump may include a compressor configured to compress a refrigerant, a first temperature sensor provided in heating pipes connected to a heating device that heats an indoor space to sense a temperature of fluid flowing through the heating pipes, and a controller. The controller may be configured to determine whether a boiler is operating to heat an indoor space or is operating to supply hot water based on a sensing value of the first temperature sensor. The compressor may operate when the controller determines that the boiler is not operating to heat the indoor space and/or determines that the boiler is operating to supply hot water.

A cooling system uses P-traps to address the oil return issues that result from a vertical separation between a compressor and a heat exchanger. Generally, the vertical piping that carries the refrigerant from the compressor to the 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. T-connections are coupled to the P-traps to allow the oil to drain out of the P-traps. The oil may then be collected and returned to the compressor.

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.

An air-conditioning device includes: a heat medium cycle circuit including: a pump, a plurality of indoor heat exchangers, and a plurality of flow control devices configured to control a flow rate of the heat medium through the heat medium cycle circuit; a heat-source-side device configured to heat or cool the heat medium; and a controller that includes a determination processing unit to determine whether the heat medium is caused to pass through the plurality of indoor heat exchangers where heat exchange is stopped, a selection processing unit to select, based on a determination from the determination processing unit, an indoor heat exchanger through which the heat medium is caused to pass from the plurality of indoor heat exchangers where heat exchange is stopped, and an instruction processing unit to instruct a release of a flow control device that corresponds to the indoor heat exchanger selected.

A method controls a refrigerator. The refrigerator includes a compressor using that includes a piston and uses refrigerant as lubricant for the piston, and the method includes determining an end time point of a refrigerant recovery operation based on a driving input value of the compressor to thereby reduce abrasion of the piston and power consumption.