Analysis of the issue of reduced outlet temperature in U-tube shell and tube heat exchangers
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Piping steam, pressure 0.35 MPa. Shell-side process medium, flow rate 1300 (the feed flow can be adjusted by a few hundred). Due to tube bundle corrosion, a new tube bundle was installed; the material is 825 with a wall thickness of 25*2, and as a result the outlet temperature dropped to 36°C. It used to be fifty, sixty, or seventy degrees, but now it can’t reach such high temperatures at all. Causes product loss? ? ? Have any of you sailors encountered this kind of situation? ? ? ? ?
Steam flow rate: 230 m3/h
Check whether the valve opening for the same steam flow has increased; if it has, it indicates poor heat exchange. Also, check if there are any changes in the steam inlet and outlet pressures, as well as whether the drainage is functioning properly. Are there any other changes besides the change in the tube bundle material, such as the number and distribution of baffle plates, as well as the number, spacing, and arrangement of the tubes? We need to check again whether there is a possibility of the AB sides of the end cap being installed incorrectly. The information you've provided is quite limited; I can only analyze and rule things out one by one
Steam inlet: only a control valve is available; PCV pressure relief is carried out upstream
The material has not been changed; it has just been replaced. The quantity is the same, and the distribution and other aspects appear to be identical to the original
It can be determined by the pressure at the steam inlet and outlet
Because there was only a on-site form, so I didn’t pay too much attention to it. But the data volume remains the same; even with a bypass at 240, it can reach 300, yet it still doesn’t help