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US 12,298,017 B2Granted
Air-conditioning apparatus
AssigneeMitsubishi Electric Corporation
InventorKohei Najima
Life of this patent
Estimating the term…
Abstract
The air-conditioning apparatus includes: a refrigerant circuit in which a compressor, an outdoor heat exchanger, the expansion valve, and an indoor heat exchanger are connected by pipes; and a controller. The controller includes a valve opening-degree adjusting module, a flow-rate determination module, and a clogging determination module.
Claims12
An air-conditioning apparatus comprising:
- a refrigerant circuit in which a compressor, an outdoor heat exchanger, a plurality of expansion valves, and an indoor heat exchanger are connected by pipes, the plurality of expansion valves including an indoor expansion valve and a bypass expansion valve, each of the expansion valves respectively having an opening degree;
- and
- a controller configured to control the opening degree of each of the expansion valves,
- wherein the controller is configured to, for each of the expansion valves,
- produce a control signal for control of the opening degree of the expansion valve,
- compare a flow rate of refrigerant on a downstream side of the expansion valve with a threshold for the flow rate of the refrigerant on the downstream side of the expansion valve, and
- determine that the expansion valve is clogged with foreign matter, when the control signal is a control signal to control the expansion valve such that the opening degree of the expansion valve is made constant or such that the expansion valve is moved in a closing direction in which the expansion valve is closed, and a result of comparison between the flow rate of the refrigerant on the downstream side of the expansion valve and the threshold for the flow rate of the refrigerant on the downstream side of the expansion valve indicates that the flow rate of the refrigerant on the downstream side of the expansion valve is higher than or equal to the threshold for the flow rate of the refrigerant on the downstream side of the expansion valve,
- wherein the bypass expansion valve is provided at a bypass pipe that branches off from the pipe connecting the outdoor heat exchanger and the indoor expansion valve and that joins the pipe connected to a suction side of the compressor, and
- wherein the controller is configured to
- compare a degree of superheat of suction gas with a threshold for the degree of superheat of the suction gas, thereby comparing the flow rate of the refrigerant on a downstream side of the bypass expansion valve with a threshold for the flow rate of the refrigerant on the downstream side of the bypass expansion valve, and
- determine that the flow rate of the refrigerant on the downstream side of the bypass expansion valve is higher than or equal to the threshold for the flow rate of the refrigerant on the downstream side of the bypass expansion valve, when the result of the comparison indicates that the degree of superheat of the suction gas is less than the threshold for the degree of superheat of the suction gas.
8 more elements
An air-conditioning apparatus comprising:
- a refrigerant circuit in which a compressor, an outdoor heat exchanger, a plurality of expansion valves, and an indoor heat exchanger are connected by pipes, the plurality of expansion valves including an indoor expansion valve and a bypass expansion valve, each of the expansion valves respectively having an opening degree;
- a controller configured to control the opening degree of each of the expansion valves;
- and
- an accumulator connected to the refrigerant circuit,
- wherein the controller is configured to, for each of the expansion valves,
- produce a control signal for control of the opening degree of the expansion valve,
- compare a flow rate of refrigerant on a downstream side of the expansion valve with a threshold for the flow rate of the refrigerant on the downstream side of the expansion valve, and
- determine that the expansion valve is clogged with foreign matter, when the control signal is a control signal to control the expansion valve such that the opening degree of the expansion valve is made constant or such that the expansion valve is moved in a closing direction in which the expansion valve is closed, and a result of comparison between the flow rate of the refrigerant on the downstream side of the expansion valve and the threshold for the flow rate of the refrigerant on the downstream side of the expansion valve indicates that the flow rate of the refrigerant on the downstream side of the expansion valve is higher than or equal to the threshold for the flow rate of the refrigerant on the downstream side of the expansion valve,
- wherein the bypass expansion valve is provided at a bypass pipe that branches off from the pipe connecting between the outdoor heat exchanger and the indoor expansion valve and that joins the pipe connected to a suction side of the compressor, and
- wherein the controller is configured to
- compare an increased amount of an amount of refrigerant in the accumulator with a refrigerant-amount threshold that is a threshold for the amount of the refrigerant, thereby comparing the flow rate of the refrigerant on a downstream side of the bypass expansion valve with a threshold for the flow rate of the refrigerant on the downstream side of the bypass expansion valve, and
- determine that the flow rate of the refrigerant on the downstream side of the bypass expansion valve is higher than or equal to the threshold for the flow rate of the refrigerant on the downstream side of the bypass expansion valve, when the result of the comparison indicates that the increased amount of the amount of the refrigerant in the accumulator is higher than or equal to the refrigerant-amount threshold.
9 more elements
Dependencies are inferred from the claim text.