One end of the floating head heat exchanger's tube plate is fixed to the shell, while the other end's tube plate can freely float inside the shell. The shell and tube bundle are free to expand, so when the temperature difference between the two media is large, no temperature stress is generated between the tube bundle and the shell. The floating head end is designed as a detachable structure, allowing the tube bundle to be easily inserted or removed from the shell. (It can also be designed as non detachable). This provides convenience for maintenance and cleaning. But the structure of the heat exchanger is relatively complex, and the floating end small cover cannot know the leakage situation during operation. Therefore, special attention should be paid to its sealing during installation advantage: (1) The tube bundle can be extracted for easy cleaning of the tube and shell side (2) The temperature difference between media is not limited; (3) Can work under high temperature and high pressure, generally with a temperature of less than or equal to 450 degrees and a pressure of less than or equal to 6.4 megapascals; (4) Can be used in situations with severe scaling (5) Can be used in environments where the pipeline is prone to corrosion.