Core of shell-and-tube heat exchanger

The utility model discloses a core of a shell-and-tube heat exchanger. A flanging is added on a tube sheet hole on the basis of the original structure in the design. Due to the design scheme, the soldering joint area with a tube is enlarged, and the strength of the welding seam is enhanced, so that the soldering seam is not easy to fracture. By adopting a composite tube sheet form, the strength at the root of the tube is reinforced, and the stress at the connecting position of the tube and the tube sheet is reduced, so that the tube can better bear the mechanical stress and the thermal stress of the using environment, and further the tube is not easy to fracture; in a word, due to the technical scheme, the defects of the original scheme are solved, and the core can better adapt to the requirement of using reliability.