7 results about "Variable refrigerant flow" patented technology

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.

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.

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.

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.

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.

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.