Refrigeration apparatus for executing a pump down

摘要

An air-conditioning apparatus includes an outdoor unit, an indoor unit having an indoor heat exchanger, and a controller for executing a pump down operation. The outdoor unit has an accumulator of a capacity (Va), a compressor, an outdoor heat exchanger, an expansion valve, a large-diameter tube, which are joined by refrigerant pipes. The capacity (Vhi) of the indoor heat exchanger is greater than the capacity (Vho) of the outdoor heat exchanger. The large-diameter tube, which is larger in diameter than the refrigerant pipes, is provided so that the capacity (Vt) of the large-diameter tube satisfies the formula: capacity (Vt)>capacity (Vhi)−capacity (Vho)−capacity (Va).

主权项

1. A refrigeration apparatus comprising:
a heat source-side unit having a refrigerant container, a compressor, a heat source-side heat exchanger; an expansion valve; a large-diameter tube; a liquid refrigerant-side shutoff valve, and a gas refrigerant-side shutoff valve, which are joined together by refrigerant pipes; a usage-side unit having a usage-side heat exchanger joined at one end to the liquid refrigerant-side shutoff valve via a liquid refrigerant communication pipe and joined at an other end to the gas refrigerant-side shutoff valve via a gas refrigerant communication pipe; and a controller configured to execute a pump down operation in order to collect refrigerant in the heat source-side unit, the refrigerant container having a capacity Va, the heat source-side heat exchanger having a capacity Vho, the usage-side heat exchanger having a capacity Vhi, with the capacity Vhi being greater than the capacity Vho, the large-diameter tube having a larger diameter than the refrigerant pipes of the heat source-side unit, the large-diameter tube being configured to accumulate excess refrigerant, and the large diameter tube being provided between the heat source-side heat exchanger and the liquid refrigerant-side shutoff valve so that a capacity Vt of the large-diameter tube satisfies:
capacity Vt>capacity Vhi−capacity Vho−capacity Va>0, and the larger-diameter tube including two ends in a longitudinal direction thereof, with one of the two ends being positioned on a liquid side of the heat source-side heat exchanger in the heat source-side unit.