When designing heat exchangers, what safety margin do domestic design institutes generally provide?

Cooler 1.2-1.5 Condenser 1.5-2.0

This post was last edited by wiseboy on 2011-12-4 19:47. “wangtianyi*ao: Is it a rule in your company?” Could you provide a theoretical source? ”. 1. It should be said that if you calculate it accurately, what’s wrong with a wealth level of 0? Since it’s excess, any amount will do; there can be no theory behind it, nor is it necessary. In many cases, choosing a larger margin reflects the designer’s lack of confidence in the accuracy of their calculations, or it is done intentionally to prevent increased fouling of the heat exchanger over time (such as corrosion of the heat exchange tubes). If, during the calculation, the dirt resistance has already been set at a high value by taking into account its increase in the later stages of operation, then it is no problem to use a margin of 0 ； 2. In the petrochemical industry, when I use Heat Exchanger Master (Them) for calculations, I use a margin of 10%, and no problems have occurred over the years. Overall, the design in the petrochemical industry is relatively rough, with often large tolerances. In industries such as light manufacturing and refrigeration, they use Them to carry out calculations, often using a margin of 0-5% ； 3. This also relates to the designer’s *habits. For example, in a large design institute, their fouling resistance is never less than 0.0004 m2.C/W, even when the degree of fouling is low, and the safety factor is always set at 10%. But this is on the premise of using software for calculation, which yields relatively accurate results. If the heat transfer coefficient K is obtained by consulting a manual, the error in K is astonishingly large; the error is often several times higher, and in such cases it makes no sense to talk about margin of safety.