GAS-LIQUID SEPARATOR

A gas-liquid separator is capable of collecting liquid at a position downstream of a swirling flow generator regardless of a flow rate of the gas-liquid two-phase fluid. A gas-liquid separator (16) includes a swirling flow generator (22) within the pipe member (21) through which a gas-liquid two-phase fluid flows. The swirling flow generator is configured to swirl the gas-liquid two-phase fluid to separate gas and liquid therefrom by swirling the gas-liquid two-phase fluid by the swirling flow generator (22). The swirling flow generator (22) includes blades (32) that are spirally curved about a central axis (O1) of the pipe member (21). The distal ends (32a) of the blades (32) are continuous over an entire circumference of the pipe member (21) when the pipe member (21) is viewed from an axial direction thereof. A communication portion (34) is provided between the pipe member (21) and the swirling flow generator (22) by forming a bulging portion (25d). The bulging portion (25d) is formed on an inner circumferential surface (25a) of the pipe member (21) to extend in the axial direction. The communication portion (34) is configured to communicate a first space (X) upstream of the swirling flow generator (22) with a second space (Y) downstream of the swirling flow generator (22) by the bulging portion (25d).