| 摘要 |
A part replacement method replaces a part of a refrigeration cycle apparatus including a compressor, a heat source side heat exchanger, an expansion device, a heat exchanger related to heat medium, and first and second refrigerant flow closing devices. The first and second refrigerant flow closing devices control a flow of a refrigerant into and out of an outdoor unit accommodating the compressor and the heat source side heat exchanger. The method includes a pump-down step of closing the first refrigerant flow closing device, allowing the refrigerant in a pressure reduction section to flow into the outdoor unit and reducing a pressure in the reduction section until a set pressure or time is reached, a flow closing step of closing the second refrigerant flow closing device, and a part replacement step of removing the part from the refrigerant circuit by heating to replace the part. |
| 主权项 |
1. A method for replacement of a part of a refrigeration cycle apparatus including a compressor that compresses a flammable refrigerant, a first heat exchanger capable of functioning as a condenser condensing the refrigerant by heat exchange, an expansion device that controls a pressure of the refrigerant, a second heat exchanger capable of functioning as an evaporator evaporating the refrigerant by heat exchange, a first refrigerant flow closing device, a second refrigerant flow closing device, and a controller, the compressor, the first heat exchanger, the expansion device, and the second heat exchanger being connected by pipes to form a refrigerant circuit, the first refrigerant flow closing device and second refrigerant flow closing device controlling a flow of the refrigerant into and out of an outdoor unit by opening and closing, the outdoor unit accommodating at least the compressor and the first heat exchanger, the method comprising:
an operation step of performing a part-replacement operation, by the controller, in which the first heat exchanger functions as a condenser and the second heat exchanger functions as an evaporator, the part-replacement operation further includes
a pump-down step of closing the first refrigerant flow closing device, by the controller, to stop the flow of the refrigerant out of the outdoor unit, allowing the refrigerant in a pressure reduction section excluding the outdoor unit in the refrigerant circuit to flow into the outdoor unit so as to be recovered within the outdoor unit, and reducing a pressure in the pressure reduction section until the pressure becomes equal to or less than a set pressure, the set pressure being determined so that the refrigerant in the pressure reduction section in the refrigerant circuit does not undergo ignition,a flow closing step of closing the second refrigerant flow closing device by the controller; and a part replacement step of, after the performing of the part-replacement operation by the controller, removing the part from the refrigerant circuit by heating and replacing the part with a new part, the part replacement step being performed after the pressure in the pressure reduction section has become equal to or less than the setting pressure, wherein the set pressure is a pressure less than a value expressed by LFL×1000×R×T/M (Pa) where M (g/mol) denotes a molecular weight of the refrigerant, R (Pa×L/K×mol) denotes a gas constant, T (K) denotes a refrigerant temperature in the refrigerant circuit, and LFL (kg/m3) denotes a lower flammability limit of the refrigerant. |
