A method for determining a level of refrigerant charge in a cooling circuit of an air-conditioning system and a module for leak detection are provided. The method includes determining a total quantity of refrigerant contained in the cooling circuit of the air-conditioning system solely based on data internal to the air-conditioning system.

A multi-stage refrigeration system (100) includes: a refrigeration loop (110), which includes a gas suction port of a multi-stage compressor (111), a condenser (112), a first throttling element (113), an evaporator (114) and an exhaust port of the multi-stage compressor which are sequentially connected through pipelines; an economizer branch (120), which includes an economizer (121), a second throttling element (122) and a first control valve (123), the economizer having an economizer liquid inlet connected to the condenser via the first throttling element, an economizer liquid outlet connected to the evaporator via the second throttling element, and an economizer exhaust port connected to an intermediate stage of the multi-stage compressor via a control valve; and a bypass branch (130), which is joined to the evaporator from the downstream of the second throttling element and connected to the condenser via the first throttling element, and on which a second control valve (131) is arranged.

A refrigerant measurement adjustment system includes: a refrigerant sensor for a building and configured to measure an amount of refrigerant present in air outside of a refrigeration system of the building; and an adjustment module configured to: adjust the amount of refrigerant measured based on an adjustment to produce an adjusted amount; and determine the adjustment based on at least one of: an air temperature; an air pressure; a relative humidity of air; a mode of operation of the refrigeration system; a change in the measurements of the refrigerant sensor over time; and whether a blower that blows air across a heat exchanger of the refrigeration system located within the building is on.

The present disclosure relates to a multi-circuit heating, ventilation, and air conditioning (“HVAC”) system for use with a first refrigerant in a first refrigerant circuit and a second refrigerant in a second refrigerant circuit. The second refrigerant circuit is fluidically isolated from the first refrigerant circuit. Additionally, a first sensor is operable to detect a leak of at least one of the first and second refrigerants or is operable to measure temperature or pressure from the first refrigerant circuit or the second refrigerant. The multi-circuit HVAC system further including a controller programmed to receive the measurement from the sensor to identify the circuit or circuits that are leaking, to turn off operation of the leaking circuit or circuits, and if only one circuit is leaking, operate only the other of the circuits.

A thermal cell panel system for heating and cooling using a refrigerant includes a plurality of solar thermal cell chambers, and a piping network for a flow of the refrigerant through the plurality of solar thermal cell chambers. In addition, the system includes a compressor having a motor coupled to a variable frequency drive (“VFD”), where the compressor is coupled to the piping network upstream of the plurality of solar thermal cell chambers and the VFD is configured to adjust a speed of the motor in response to the pressure of the refrigerant within the plurality of solar thermal cell chambers. The piping network includes an inlet manifold coupled to the inlet of each solar thermal cell chamber, and an outlet manifold coupled to the outlet of each solar cell chamber.

Embodiments of a pressure switch assembly having a quick connect capillary tube are disclosed. One embodiment, among others, has an elongated cylindrical capillary tube for attachment to a refrigeration line so that refrigeration fluid pressure in the refrigeration line can be sensed. A quick connect coupling is connected to the shutoff valve. A shutoff valve is designed to open and close fluid communication between the capillary tube and the quick connect coupling when the quick connect coupling is coupled and decoupled, respectively. A switch body is connected to the quick connect coupling and has first and second electrical connections. The switch body has an internal on/off switch designed to electrically connect and electrically disconnect the first and second electrical connections based upon a predetermined set point of pressure associated with refrigeration fluid that is in communication with the switch body.

A refrigerant circuit includes a first compressor, a second compressor, a heat-source-side heat exchanger, an expansion mechanism, and a use-side heat exchanger. The refrigerant circuit is capable of performing a single-stage compression operation in which one of the first compressor and the second compressor is driven and the other is stopped, and a two-stage compression operation in which both the first compressor and the second compressor are driven. The control unit controls the refrigerant circuit so that, of the single-stage compression operation and the two-stage compression operation, an operation with a higher compression efficiency is performed.

A subcooling controller includes a sensor and a processor. The sensor measures one or more of a temperature external to a first heat exchanger that removes heat from carbon dioxide refrigerant, a temperature of the carbon dioxide refrigerant, and a pressure of the carbon dioxide refrigerant. The processor determines that one or more of the measured temperature external to the first heat exchanger, the temperature of the carbon dioxide refrigerant, and the pressure of the carbon dioxide refrigerant is above a threshold and in response to that determination, activates a subcooling system. The subcooling system includes a condenser, a second heat exchanger, and a compressor. The condenser removes heat from a second refrigerant. The second heat removes heat from the carbon dioxide refrigerant stored in a flash tank. The compressor compresses the second refrigerant from the second heat exchanger and sends the second refrigerant to the condenser.

A refrigeration system includes a rotary pressure exchanger fluidly coupled to a low pressure branch and a high pressure branch. The rotary pressure exchanger is configured to receive the refrigerant at high pressure from the high pressure branch, to receive the refrigerant at low pressure from the low pressure branch, and to exchange pressure between the refrigerant at high pressure and the refrigerant at low pressure, and wherein a first exiting stream from the rotary pressure exchanger includes the refrigerant at high pressure in the supercritical state or the subcritical state and a second exiting stream from the rotary pressure exchanger includes the refrigerant at low pressure in the liquid state or the two-phase mixture of liquid and vapor.

Provided is a measure against a refrigerant leak. A heat load processing system has a plurality of refrigerant circuits and includes a plurality of device units, a casing that collectively houses the plurality of device units configuring the different refrigerant circuits, a refrigerant leak detector that individually detects a refrigerant leak in the respective refrigerant circuits, and a controller. The device units include a heat exchanger that is connected to a refrigerant pipe and a heat medium pipe as a device configuring one of the refrigerant circuits. When the refrigerant leak detector detects the refrigerant leak, the controller performs refrigerant leaking circuit identification processing for identifying a refrigerant circuit in which the refrigerant leak is occurring and a refrigerant leak third control for changing an operating state of a predetermined refrigerant circuit based on a result of the refrigerant leaking circuit identification processing.