Tubular maintenance-free heat exchanger

The invention relates to a heat exchanger, in particular to a tubular maintenance-free heat exchanger. The invention provides a tubular maintenance-free heat exchanger which comprises a shell, a front tube box, a rear tube box, a flange, a circular tube plate, a heat transfer tube bundle, a baffle plate, a fluid B inlet tube and a fluid B outlet tube, and further comprises a partition plate, a fluid A inlet tube and a fluid A outlet tube. The side wall of the partition plate makes contact with the front end face of the circular tube plate, the upper portion and the lower portion of the front tube box communicate with a fluid A inlet tube and a fluid A outlet tube correspondingly, and a cleaning assembly for cleaning the inner wall of the heat transfer tube bundle is slidably installed on the inner wall of the heat transfer tube bundle. Dirt in all the heat transfer tube bundles can be continuously wiped off through the cleaning assembly and the rotating mechanism, a second reciprocating lead screw drives a sc