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12 results about "Variable refrigerant flow" patented technology

Variable refrigerant flow (VRF), also known as variable refrigerant volume (VRV), is an HVAC technology invented by Daikin Industries, Ltd. in 1982. Like ductless minisplits, VRFs use refrigerant as the cooling and heating medium. This refrigerant is conditioned by a single outdoor condensing unit, and is circulated within the building to multiple indoor units.

Power failure detection circuit and control circuit for VRF system

The present application relates to a power failure detection circuit, the circuit comprises: a rectifying circuit for full-wave rectifying an alternating current voltage so as to obtain a first voltage; a switching circuit for converting the first voltage into a periodic voltage pulse; and a judgment circuit for providing an output signal to a fan control circuit for closing a fan when the periodic voltage pulse is not received within a preset time period, and providing the output signal to a micro-control unit for closing an electronic expansion valve. The present application also relates to a control circuit for a variable refrigerant flow VRF system.
Owner:CARRIER CORP

Variable air variable refrigerant flow (VAVRF)

PendingUS20260043575A1Mechanical apparatusLighting and heating apparatusVariable refrigerant flowAir treatment
The present disclosure describes various embodiments of a new HVAC system and apparatuses (and related methods) that combine the efficiencies of VRF and VAV systems. An exemplary system comprises a plurality of indoor units located in different zones of a building, each comprising a damper operable to modulate airflow through the indoor unit into a building space and a valve operable to modulate a flow of refrigerant through the indoor unit; an air handling unit having a supply fan that is configured to generate the airflow that is received by the plurality of indoor units; and a controller unit operable to control the damper and the valve simultaneously for each of the plurality of indoor units, wherein the controller unit is operable to control the supply fan and an amount of airflow generated by the supply fan.
Owner:UNIV OF FLORIDA RESEARCH FOUNDATION INC

Household modular energy station

PendingCN120538208AEnergy recovery in ventilation and heatingHeat pumpsIceboxVariable refrigerant flow
The invention discloses a household modular energy station, which has the one-to-many integration advantage of a regional energy station, and adopts a variable refrigerant flow method to perform flow distribution of a terminal by controlling the refrigerant circulation amount of a compressor and the refrigerant flow entering an indoor heat exchanger. And in response to the call of energy conservation and emission reduction, a total heat recovery measure is taken on the condenser side, so that the aim of environmental protection is fulfilled. Heat exchangers of products such as a refrigerator, a heat pump water heater, an air conditioner, an oven and a clothes dryer form various modular energy terminals, and other system hosts are combined into a set of large system to be placed outdoors for operation so as to reduce cost and improve efficiency. A user can purchase corresponding energy terminals for rapid combination according to family needs. And after calculation configuration is carried out on the modular energy station, overall decoration arrangement is carried out. According to the invention, multiple purposes are achieved through centralized energy supply and modular terminals.
Owner:周隽杰

Variable refrigerant flow air conditioning system

PCT designated stageWO2026091392A9Variable refrigerant flowControl room
The present application discloses a variable refrigerant flow air conditioning system, comprising: an outdoor unit, comprising a compressor and an outdoor expansion element; a plurality of indoor units connected to the outdoor unit by means of refrigerant piping, and each indoor unit comprising an indoor expansion element; and a control apparatus configured for controlling the outdoor unit and the plurality of indoor units. When heating, after receiving a shutdown or stop command, the control apparatus executes an evacuation operation, so that refrigerant on the outdoor unit side moves toward the indoor unit side. The control apparatus may be configured to perform control so as to achieve an equilibrium state between pressure at a suction side and pressure at a discharge side of the compressor.
Owner:QINGDAO HISENSE HITACHI AIR CONDITIONING SYST

State processing method and apparatus for variable refrigerant flow system, storage medium and electronic device

Disclosed in the embodiments of the present application are a state processing method and apparatus for a variable refrigerant flow system, a storage medium and an electronic device. The method comprises: acquiring target system configuration information and target device operation information of a target variable refrigerant flow system; on the basis of the target system configuration information, performing system diagram matching processing on the target variable refrigerant flow system to obtain a target system schematic diagram component; and, on the basis of the target device operation information, performing system operating state configuration on the target system schematic diagram component to obtain a target system operating state topological graph. The technical solution is used to combine obtained target system configuration information and target device operation information of target variable refrigerant flow systems, thereby configuring target system operating state topological graphs.
Owner:SHANGHAI MEICON INTELLIGENT CONSTR CO LTD +1

Control scheme for automatic fan mode for use with variable refrigerant flow systems

An HVAC system includes a first indoor heat exchanger coupled to an outdoor heat exchanger and disposed in a first zone. A second indoor heat exchanger is coupled to the outdoor heat exchanger and disposed in a second zone. A compressor is coupled to the outdoor heat exchanger, the first indoor heat exchanger, and the second indoor heat exchanger. A first circulation fan is positioned to circulate air around the first indoor heat exchanger and a second circulation fan is positioned to circulate air around the second indoor heat exchanger. A zone controller is coupled to the first indoor heat exchanger and configured to measure a temperature in the first zone, compare the measured temperature to a setpoint temperature of the first zone, and responsive to a difference between the measured temperature and the setpoint temperature, adjust a speed of the first circulation fan independent the second circulation fan.
Owner:LENNOX IND INC

HVAC system for indoor agriculture

Multiple air handling units feeding into a common air distribution system are used to provide both latent and sensible temperature control. When dehumidification without sensible cooling is required, different air handling units feeding into a common distribution system may be operated in different modes so that both cooling and reheating are occurring simultaneously. The result is an energy efficient means of controlling both ambient air temperature and relative humidity. Air handling units such as water source heat pumps and variable refrigerant flow (VRF) units may be employed.
Owner:TRANE INTERNATIONAL INC

Variable refrigerant flow air conditioning system

PCT designated stageWO2026091392A1Mechanical apparatusCompression machines with several evaporatorsVariable refrigerant flowControl room
The present application discloses a variable refrigerant flow air conditioning system, comprising: an outdoor unit, comprising a compressor and an outdoor expansion element; a plurality of indoor units connected to the outdoor unit by means of refrigerant piping, and each indoor unit comprising an indoor expansion element; and a control apparatus configured for controlling the outdoor unit and the plurality of indoor units. When heating, after receiving a shutdown or stop command, the control apparatus executes an evacuation operation, so that refrigerant on the outdoor unit side moves toward the indoor unit side. The control apparatus may be configured to perform control so as to achieve an equilibrium state between pressure at a suction side and pressure at a discharge side of the compressor.
Owner:QINGDAO HISENSE HITACHI AIR CONDITIONING SYST

Oil return control method and apparatus for variable refrigerant flow (VRF), and electronic device and vrf system

PendingEP4589205A4CompressorMechanical apparatusVariable refrigerant flowRefrigerant
An oil return control method and apparatus for variable refrigerant flow (VRF), and a VRF system. The oil return control method for VRF comprises: when a VRF system needs to enter an oil return operation, dividing, according to an operating state of each I indoor unit, indoor units into a first indoor unit and a second indoor unit, wherein the oil return operation comprises a plurality of oil C return stages; and using different control strategies at each oil return stage, so as to control the frequency of a compressor of the VRF Lq system and control the opening degree of an indoor unit valve of at least one of the first indoor unit and the second indoor unit.
Owner:GREE ELECTRIC APPLIANCE INC OF ZHUHAI

Method for controlling variable refrigerant flow air conditioner, variable refrigerant flow air conditioner, and storage medium

ActiveUS12669256B2ThermodynamicsVariable refrigerant flow
Disclosed are a method for controlling a variable refrigerant flow (VRF) air conditioner, a VRF air conditioner, and a computer-readable storage medium. The method includes: obtaining a target indoor unit in a warming stage among started indoor units; determining a target superheat degree according to a working condition parameter of the target indoor unit; and adjusting an operating parameter of an electronic expansion valve of the target indoor unit according to the target superheat degree.
Owner:GD MIDEA AIR CONDITIONING EQUIP CO LTD

Systems and methods for controlling variable refrigerant flow systems using artificial intelligence

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.
Owner:TYCO FIRE & SECURITY GMBH