Air conditioner

Abstract

An air conditioner (1) where the pressure in high-pressure gas piping is reduced to prevent liquid refrigerant stagnation in the high-pressure gas piping caused by condensation. The air conditioner (1) performs refrigerant amount determination operation for determining the amount of the refrigerant in a refrigerant circuit (10), and the air conditioner (1) has a heat source unit (2), utilization units (3a-3c), expansion mechanisms (V2, V9a-V9c), first refrigerant gas piping (52), second refrigerant gas piping (53), refrigerant liquid piping (51), changeover mechanisms (4a-4c), bypass circuits (27, 43a-43c), bypass circuit open / close means (V3, V13a-V13c), and a control section (8). The changeover mechanisms can change over between a first state and a second state. The bypass circuit open / close means is provided in a bypass circuit bypassing the first refrigerant gas piping and the second refrigerant gas piping and opens and closes the bypass circuit. The control section opens the bypass circuit open / close means before the refrigerant amount determination operation.

Description

technical field [0001] The present invention relates to a refrigerant circuit of an air conditioner and an air conditioner having the refrigerant circuit. Background technique [0002] Conventionally, in order to determine that the amount of refrigerant in the refrigerant circuit of an air conditioner is insufficient, a method of simulating the characteristics of the refrigeration cycle and using the calculation results to determine the insufficient amount of refrigerant has been proposed (for example, refer to Patent Document 1). [0003] Patent Document 1: Japanese Patent Laid-Open No. 3-186170 [0004] However, in the technology of Patent Document 1, for a multi-type air conditioner that can perform simultaneous cooling and heating operations, when the refrigerant quantity determination operation is performed under the cooling operation of all rooms, due to the high-pressure gas piping from the outdoor unit to the cooling and heating selector It is closed on the side of ...

AI Technical Summary

Problems solved by technology

[0004] However, in the technology of Patent Document 1, for a multi-type air conditioner that can perform simultaneous cooling and heating operations, when the refrigerant quantity determination operation is performed under the cooling operation of all rooms, due to the high-pressure gas piping from the outdoor unit to the cooling and heating selector It is closed on the side of the heating and cooling selection part, so the refrigerant will condense and accumulate in the piping, and the detection error may increase

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