Improved waste heat boiler

Abstract

The invention discloses an improved waste heat boiler, comprising a tube box, a plurality of U-shaped heat exchange tubes and a pressure bearing tube plate, wherein the U-shaped heat exchange tubes are fixed in the tube box by the pressure bearing tube plate along the axial direction of the tube box in a fountain mode or a cross mode. In the invention, the arrangement mode of the heat exchange tubes is improved based on a tube array waste heat boiler having larger temperature difference between the inlet and the outlet of a tube pass, and the temperature difference stress generated in the tube box and the tube plate is reduced, so that the stress distribution in the tube box and the tube plate is more uniform, and the service life of the tube plate is prolonged.

Description

technical field [0001] The invention relates to the technical field of shell and tube waste heat boilers, in particular to an improved waste heat boiler. Background technique [0002] In carbon monoxide shift, synthetic ammonia and other processes, the temperature of the shift gas and synthesis gas (hereinafter collectively referred to as reaction gas) exiting from the bottom of the reactor is usually between 400°C and 500°C, and the working pressure is medium or high pressure. The main component of high temperature shift gas is H 2 , CO, CO 2 , water vapor and a small amount of special corrosive media; the main component of high-temperature syngas is H 2 , N 2 , NH 3 Wait. The medium has a high partial pressure of hydrogen, is flammable and explosive, and has a high-temperature special medium corrosion environment, such as nitriding corrosion of high-temperature syngas. [0003] The high-temperature reaction gas often needs to exchange heat through the waste heat boil...

AI Technical Summary

Problems solved by technology

Under the influence of hydrogen and nitrogen corrosion on the high-temperature medium side, the higher peak stress is likely to cause crack growth, which will cause partial or even overall failure of the equipment

[0009] 3. Medium and high pressure waste heat boilers are often sealed with flange flat covers at the end of the tube box. The temperature difference between the inlet and outlet medium is large, which will cause uneven axial expansion of the tube boxes on both sides of the split-pass partition after heating, and damage the flange end faces and tubes. The verticality of the box axis will reduce the reliability of the seal and even cause the seal to fail

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