Horizontal tubular heat exchanger

The invention discloses a horizontal heat exchanger which comprises a shell. A supporting transverse column, a heat exchange pipe, a liquid inlet structure, an exhaust structure and a circulation structure are arranged in the shell. The liquid inlet structure comprises a liquid inlet pipe arranged on the shell, a collection inlet pipe connected with the liquid inlet pipe, a liquid inlet sealing plate arranged on the side, close to the heat exchange pipe, of the collection inlet pipe in a covering mode, and a connecting inlet pipe used for connecting a plurality of liquid inlet holes in the liquid inlet sealing plate with the heat exchange pipe. The exhaust structure comprises an exhaust pipe arranged on the shell, a collection outlet pipe connected with the exhaust pipe, an air outlet sealing plate arranged on the side, close to the heat exchange pipe, of the collection outlet pipe in a covering mode, and a connecting outlet pipe used for connecting a plurality of air outlet holes in the air outlet sealing pl