A system for measuring and recharging an air conditioning system includes a vent sensor configured to be coupled to an outlet vent of an air conditioning system. The vent sensor is configured to measure at least one parameter of an air flow from the outlet vent. A processor is in signal communication with the vent sensor. The processor is configured to receive the at least one parameter of the air flow and determine a current refrigerant level of the air conditioning system.

A refrigeration system includes a main refrigeration circuit for holding refrigerant fluid, the main refrigeration circuit including: a compression device 12, a heat rejecting heat exchanger 14, an expansion device 18 and a heat absorbing heat exchanger 16. In addition, the refrigeration system includes a buffer tank 20 attached to the main refrigeration circuit, with valves 22, 24 for controlling flow of refrigerant fluid between the main refrigeration circuit and the buffer tank 20. The refrigeration system is arranged such that the valves 22, 24 are controlled to transfer refrigerant fluid between the main refrigeration circuit and the buffer tank 20 based on a measure of sub-cooling in the main refrigeration circuit.

An air conditioner including a refrigerant circuit including a compressor, an outdoor heat exchanger, an outdoor expansion valve, an indoor expansion valve, and an indoor heat exchanger. The refrigerant circuit including an auxiliary heat exchanger provided on a refrigerant pipe between the outdoor heat exchanger and the indoor expansion valve and connected in series with the outdoor expansion valve, and a rectifier configured to allow a refrigerant flowing from the outdoor heat exchanger toward the indoor expansion valve in a cooling operation or a refrigerant flowing from the indoor expansion valve toward the outdoor heat exchanger in a heating operation to sequentially flow through the auxiliary heat exchanger and the outdoor expansion valve.

Disclosed is a refrigerant charge management device comprising a refrigerant charge vessel enclosing a volume, a movable impervious barrier separating the volume into a first volume and a second volume, a first port disposed in fluid communication with the first volume and configured for fluid connection to a heat pump system, and a second port disposed in fluid communication with the second volume and configured for fluid connection to the heat pump system, wherein the movable impervious barrier is configured to move in response to a difference in pressure between the first volume and the second volume thereby changing the size of the first volume and the second volume.

A method of operating a heat pump system comprising: operating the heat pump system in a demand operation heating mode, wherein the demand operation heating mode comprises controlling an opening amount of an expansion valve based on a superheat difference between a compressor inlet superheat value and a target compressor inlet superheat value, and controlling a flowrate of the refrigerant through a compressor based on a thermal demand difference between a thermal output of the indoor heat exchanger and a customer thermal demand; monitoring with the one or more controllers a parameter of the refrigerant cycle indicative of a charge imbalance condition; and transitioning operation with the one or more controllers to a charge compensation mode when the parameter satisfies a first threshold condition, wherein the charge compensation mode comprises performing with the one or more controllers a charge imbalance mitigation strategy.

A vapor compression refrigeration system having an air dehumidifying system and a heat transfer system. The dehumidifying system has a refrigerant circuit and an air circulating system transporting air from an enclosed space at least partly through the refrigerant circuit and back to the enclosed space. The refrigerant circuit carries a phase change refrigerant which picks up heat from the air passing through the air circulating system. The heat transfer system carries a fluid that will not freeze below the ambient temperature. A heat exchanger connects the refrigerant circuit to the heat transfer system to pass heat from the phase change refrigerant in the refrigerant circuit to the fluid in the heat transfer system. At least one heat removal unit in the heat transfer system to remove heat from the fluid.

A dynamic receiver is included in parallel to an expander of a heating, ventilation, air conditioning, and refrigeration (HVACR) system. The dynamic receiver allows control of the refrigerant charge of the HVACR system to respond to different operating conditions. The dynamic receiver can be filled or emptied in response to the subcooling observed in the HVACR system compared to desired subcooling for various operating modes. The HVACR system can include a line directly conveying working fluid from compressor discharge to the dynamic receiver to allow emptying of the dynamic receiver to be assisted by injection of the compressor discharge.

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.

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.

The system heats glycol water using steam generated by a boiler and heating LNG using the glycol water, thereby increasing efficiently the LNG to temperature required for an engine. In addition, the system senses LNG flowing to a glycol tank using a pressure sensor, etc. when the LNG flows to the glycol tank due to pressure difference between a fuel supplying line and a glycol circulation line generated according as a heat exchanger is broken down, and outputs the flowed LNG to the outside. As a result, the glycol circulation line may be returned to original state and stability of the system may be enhanced.