Back to results
US 11,143,439 B2Granted
Heat pump with refrigerant leak detection and pump-down method
AssigneeMitsubishi Electric Corporation
InventorsTakuya Matsuda, Makoto Wada, Yuji Motomura, Katsuhiro Ishimura
Life of this patent
Estimating the term…
Abstract
A refrigeration cycle apparatus includes a gas leakage sensor and a control device. When refrigerant leakage is detected by the gas leakage sensor, the control device performs a first mode operation to operate a compressor in such a state that a four-way valve is set to a cooling operation state, an expansion valve is opened, and a first shutoff valve is closed. After performing the first mode operation, the control device performs a second mode operation to operate the compressor in such a state that the four-way valve is set to a heating operation state and the first shutoff valve is closed.
Claims12
A refrigeration cycle apparatus comprising:
- an outdoor heat exchanger;
- a compressor;
- an accumulator;
- an indoor heat exchanger;
- an expansion valve;
- a four-way valve connected to an outlet of the compressor, an inlet of the accumulator, the outdoor heat exchanger, and the indoor heat exchanger;
- a refrigerant circuit configured to circulate a refrigerant through the compressor, the outdoor heat exchanger, the expansion valve, and the indoor heat exchanger;
- a first shutoff valve provided between the outdoor heat exchanger and the expansion valve in the refrigerant circuit;
- a refrigerant leakage detection device configured to detect refrigerant leakage from the refrigerant circuit, and
- a controller configured to control operation of at least the compressor, the expansion valve, the four-way valve, and the first shutoff valve, wherein:
- when the refrigerant leakage is detected by the refrigerant leakage detection device, the controller performs control by a first mode operation where:
- the compressor operates such that the refrigerant flows in order of the indoor heat exchanger, the accumulator, the compressor, and the outdoor heat exchanger,
- the expansion valve is opened, and
- the first shutoff valve is closed,
- after the controller performs control by the first mode operation, the controller performs control by a second mode operation where:
- the compressor operates such that the refrigerant flows in order of the outdoor heat exchanger and the accumulator, and
- the first shutoff valve is closed, and
- a position of an upper end of the outdoor heat exchanger is higher than a position of an upper end of the accumulator.
15 more elements
A refrigeration cycle apparatus comprising:
- an outdoor heat exchanger;
- a compressor;
- an accumulator;
- an indoor heat exchanger;
- an expansion valve;
- a four-way valve connected to an outlet of the compressor, an inlet of the accumulator, the outdoor heat exchanger, and the indoor heat exchanger;
- a refrigerant circuit configured to circulate a refrigerant through the compressor, the outdoor heat exchanger, the expansion valve, and the indoor heat exchanger;
- a first shutoff valve provided between the outdoor heat exchanger and the expansion valve in the refrigerant circuit;
- a refrigerant leakage detection device configured to detect refrigerant leakage from the refrigerant circuit, and
- a controller configured to control operation of at least the compressor, the expansion valve, the four-way valve, and the first shutoff valve, wherein:
- when the refrigerant leakage is detected by the refrigerant leakage detection device, the controller performs control by a first mode operation where:
- the compressor operates such that the refrigerant flows in order of the indoor heat exchanger, the accumulator, the compressor, and the outdoor heat exchanger,
- the expansion valve is opened, and
- the first shutoff valve is closed,
- after the controller performs control by the first mode operation, the controller performs control by a second mode operation where:
- the compressor operates such that the refrigerant flows in order of the outdoor heat exchanger and the accumulator, and
- the first shutoff valve is closed, and
- the refrigeration cycle apparatus further comprises:
- a bypass passage configured to bypass the refrigerant to the accumulator from between the outdoor heat exchanger and the expansion valve in the refrigerant circuit;
- and
- an internal heat exchanger provided between the outdoor heat exchanger and the expansion valve in the refrigerant circuit and configured to exchange heat between the refrigerant flowing in the bypass passage and the refrigerant flowing between the outdoor heat exchanger and the expansion valve.
18 more elements
A refrigeration cycle apparatus comprising:
- an outdoor heat exchanger;
- a compressor;
- an accumulator;
- an indoor heat exchanger;
- an expansion valve;
- a four-way valve connected to an outlet of the compressor, an inlet of the accumulator, the outdoor heat exchanger, and the indoor heat exchanger;
- a refrigerant circuit configured to circulate a refrigerant through the compressor, the outdoor heat exchanger, the expansion valve, and the indoor heat exchanger;
- a first shutoff valve provided between the outdoor heat exchanger and the expansion valve in the refrigerant circuit;
- a refrigerant leakage detection device configured to detect refrigerant leakage from the refrigerant circuit, and
- a controller configured to control operation of at least the compressor, the expansion valve, the four-way valve, and the first shutoff valve, wherein:
- when the refrigerant leakage is detected by the refrigerant leakage detection device, the controller performs control by a first mode operation where:
- the compressor operates such that the refrigerant flows in order of the indoor heat exchanger, the accumulator, the compressor, and the outdoor heat exchanger,
- the expansion valve is opened, and
- the first shutoff valve is closed,
- after the controller performs control by the first mode operation, the controller performs control by a second mode operation where:
- the compressor operates such that the refrigerant flows in order of the outdoor heat exchanger and the accumulator, and
- the first shutoff valve is closed,
- the outdoor heat exchanger has a header at a refrigerant outlet portion, and
- during control performed by the second mode operation, a refrigerant flow path extending from the header to the accumulator via the four-way valve is connected to a lower end portion of the header.
16 more elements
Dependencies are inferred from the claim text.