Falling film evaporator

Abstract

The present application discloses a falling film evaporator including a barrel that is provided with an upper distributor at an inner upper side thereof, gas barriers are respectively provided at both sides of the top of the upper distributor, at least one gas barrier is provided with sawteeth at the edge thereof, a gas flowing channel is formed by the sawteeth and the inner wall of the barrel in an encircled manner and is communicated with the gas refrigerant outlet, at the bottom of the both side walls of the upper distributor is respectively provided with a turbulent flow plate, an upper heat exchange tube group is provided below the upper distributor, a lower heat exchange tube group is provided below the upper heat exchange tube group, an oil enriched area provided with a liquid level sensor is provided below the lower heat exchange tube group, a signal output end of the liquid level sensor is connected with a signal input end of the throttle device, and oil return ports are opened at the oil enriched area. The falling film evaporator may switch between full falling film heat exchange mode and mixed falling film heat exchange mode, thereby preventing refrigerant dripping to the bottom for use in heat exchange from being insufficient or preventing refrigerant filling quantity from being too large, and meanwhile also avoiding the phenomenon of carrying liquid during air suction and improving heat transfer coefficient and heat exchange efficiency.