A refrigerant charge controller for heating, ventilation, or air conditioning (HVAC) equipment includes a processing circuit configured to analyze usage data for the HVAC equipment using a machine learning model to estimate an amount of refrigerant used by the HVAC equipment, identify a refrigerant deficiency based on the amount of refrigerant, and initiate a corrective action in response to identifying the refrigerant deficiency.

An injection-type heat exchange module includes an outer tank connected to an external condenser or an indoor condenser and a lower chamber connected to an evaporator and a compressor, an inner tank disposed so as to exchange heat with a refrigerant in the outer tank and connected to the compressor, the evaporator, or a lower portion of the outer tank, a first valve disposed at an upper end of the inner tank, a second valve rotatably coupled to a lower end of the inner tank, and an actuator connected to the first valve and the second valve to simultaneously rotate the same. The first and second valves are configured to permit flow of, expand, or block the flow of the refrigerant by rotation thereof.

An injection type heat exchange module includes an outer tank composed of an upper chamber and a lower chamber separated from each other, an inner tank disposed inside the upper chamber of the outer tank to be heat-exchangeable with the refrigerant and connected to discharge the refrigerant to the compressor, the evaporator, or the lower chamber of the outer tank, a first valve disposed on an upper end of the inner tank; a second valve rotatably coupled to a lower end of the inner tank, and an actuator simultaneously connected to the first valve and the second valve to be operated to simultaneously rotate the first valve and the second valve, and a heat management system for a vehicle applying the same.

Systems and methods are provided for detecting low refrigerant charge in a refrigeration system. Specifically, the present invention provides systems and methods for comparing refrigerant charges of the refrigeration system during at least substantial shut down.

A system for starting a refrigeration system includes a liquid line regulating valve, a liquid line charging valve, a suction line expansion valve, a suction line charging valve, and a controller. The controller is configured to override normal operation of the refrigeration system and transmit a demand signal to enable partial system operation. The controller is configured to operate the liquid line regulating valve and the liquid line charging valve to charge a receiver tank, gradually increase the demand signal to a predetermined level of partial system operation, and release the liquid line charging valve to normal operation. The controller is configured to operate the suction line expansion valve and the suction line charging valve to charge a suction line, gradually increase the demand signal to full system operation, and release the liquid line regulating valve, the suction line expansion valve, and the suction line charging valve to normal operation.

A method for monitoring a refrigerant charge in a vapour compression system (1) is disclosed, the vapour compression system (1) including a compressor unit (2), a heat rejecting heat exchanger (3), a high pressure expansion device (4), a receiver (5), at least one expansion device (9, 10), and at least one evaporator (11, 12) arranged in a refrigerant path. A change in net mass flow into or out of the receiver (5) and/or a change in net enthalpy flow into or out of the receiver (5) is detected, and a pressure inside the receiver (5) is monitored as a function of time, following the detected change in net mass flow and/or in net enthalpy flow. A time constant being representative for dynamics of the receiver (5) is derived, based on the monitored pressure as a function of time, and information regarding a refrigerant charge in the vapour compression system (1) is derived, based on the derived time constant.

A charge-verification system for a circuit including a condenser having an inlet, an outlet, and a coil circuit tube extending between the inlet and the outlet is provided. The charge-verification system may include a first of coil temperature sensor located on the coil circuit tube a first distance from the inlet and a second of coil temperature sensor located on the coil circuit tube a second distance from the inlet. The charge-verification system may also include a controller receiving a first signal from the first temperature sensor indicative of a first temperature and a second signal from the second temperature sensor indicative of a second temperature. The controller may determine which of the first signal and the second signal is closer to an actual saturated condensing temperature of the condenser.

Containers (100) for cryopreserved biological samples (102) may include an insulated housing including a cavity (108) for containing at least one cryopreserved biological sample; and a sealed reservoir (106) at least partly surrounding the cavity, the sealed reservoir including liquified gas (120) such as liquified air, the gas being kept largely liquified by a heat transfer engine (112) such as a Stirling cryocooler. A valve (114) may be provided to function as both a pressure relief valve and an inlet valve. The inlet valve may be coupled to a sensor (122) for sensing a volume of liquified gas within the sealed reservoir. The container may further include a heat exchanger (116) coupled to the heat engine and extending into the sealed reservoir.

A variable refrigerant volume system and control method thereof. The variable refrigerant volume system comprises: a compressor (1); a four-way valve (19); an indoor unit; a liquid tube (22), the first end thereof being connected to the indoor unit, the second end thereof being connected to the third valve port of the four-way valve (19), and a condenser (18) being provided on the liquid tube (22); a low pressure air pipe (23), the first end thereof being connected to the indoor unit, and the second end thereof being connected to the fourth valve port of the four-way valve (19); a refrigerant adjustment tank (6), the first port thereof being connected to the liquid tube (22), the second port thereof being connected to the low pressure air pipe (23), and the third port thereof optionally communicating with the liquid tube (22) or the low pressure air pipe (23). The refrigerant adjustment tank (6) provides refrigerant to the variable refrigerant volume system when the system requires more refrigerant, and recycles refrigerant from the variable refrigerant volume system when the system requires less refrigerant. The variable refrigerant volume system can flexibly control a refrigerant recycling amount in accordance with a refrigerant operation situation, thus ensuring system reliability.

A vehicle air conditioner with a refrigerant circuit has as components at least one evaporator, a refrigerant compressor, a refrigerant condenser, an expansion valve associated with the evaporator and at least one heat exchanger with an associated expansion valve for coupling with a coolant circuit of a heat source, wherein the components are connected by a refrigerant line. A refrigerant container is provided which is connected on the high-pressure side of the refrigerant compressor with the refrigerant line and has a refrigerant-receiving chamber with a controllable volume, and a control unit is provided with which the volume of the chamber of the refrigerant container is controlled as a function of operating parameters of the refrigerant circuit. Alternatively, the refrigerant container is connected on the high-pressure side of the refrigerant compressor with the refrigerant line by way of a branch line.