Supersonic expansion refrigeration and cyclone separation device for natural gas

摘要

A supersonic expansion refrigeration and cyclone separation device for natural gas comprises an equal-diameter casing straight-pipe (2), static cyclone blades (3), a central body (4), a casing expanded pipe (5), a diffusing pipe (9), and a liquid discharging pipe (11). At the left end of the equal-diameter casing straight-pipe (2) is a saturated moisture inlet (18), at the right end of the diffusing pipe (9) is a dry gas outlet (10), and at the lower end of the liquid discharging pipe (11) is a liquid outlet (12). The equal-diameter casing straight-pipe (2) and the central body (4) form an annular contracting-expanding spray pipe with the changing cross section. The annular contracting-expanding spray pipe comprises a subsonic contracting flow passage (17), a spray pipe throat portion (16), and a supersonic expanding flow passage (15). The static cyclone blades (3) are evenly mounted in the subsonic contracting flow passage (17). The diffusing pipe (9) and the central body (4) form an annular dry gas diffusing flow passage (14). The casing expanded pipe (5) and the diffusing pipe (9) form a liquid separation port (23) and a liquid accumulation cavity (13). The liquid accumulation cavity (13) communicates with the liquid discharging pipe (11). Natural gas enters through the saturated moisture inlet (18), and then cyclone is generated through the static cyclone blades (3). Then, the cyclone enters the annular contracting-expanding spray pipe for expansion to achieve the supersonic speed. Water and heavy hydrocarbon in the natural gas are condensed by the low temperature and low pressure. Condensed liquid droplets are separated from the gas phase by a centrifugal force, and are discharged through the liquid outlet (12) after entering the liquid accumulation cavity (13) through the liquid separation port (23). The dry gas enters the annular dry gas diffusing flow passage (14) and is discharged through the dry gas outlet (10) after pressure energy recovery. The device has a simple structure and high machining accuracy, runs stably and reliably, and has high separation efficiency.