High-efficiency self-circulation evaporator

The utility model discloses a high-efficiency self-circulation evaporator, which comprises a lower pipe box, a pipe shell, an upper pipe box, heat exchange pipes, a central circulation pipe, an upper pipe plate and a lower pipe plate, wherein the upper mouth and the lower mouth of the pipe shell are respectively and fixedly connected with the upper pipe plate and the lower pipe plate; the upper pipe plate is connected with the lower mouth of the upper pipe box in a sealing way; the lower pipe plate is connected with the upper mouth of the lower pipe box in a sealing way; the lower pipe box is provided with a liquid inlet; the upper pipe box is provided with an air exhaust; the pipe shell is provided with a heating medium inlet and a heating medium outlet; a plurality of heat exchange pipes penetrate between the upper pipe plate and the lower pipe plate and are matched in a sealing way; the middle parts of the upper pipe plate and the lower pipe plate are hollow, the hollow part of the upper pipe plate and the