I would like to ask: when there is both steam condensation and liquid cooling in the shell side, how is the convective heat transfer coefficient calculated?

After you graduate and work in a company where reaction vessels or heat exchangers use steam for heat exchange, you can get in touch with me. I specialize in carrying out steam energy-saving upgrades on production lines for manufacturing enterprises, which helps to reduce their steam consumption and thus lower their production costs. Your work performance will also improve significantly by then

For segmented calculation, you can refer to Professor Shi Meizhong’s book \"Principles and Design of Heat Exchangers\", the one with an orange-red cover

Is it a steam heater, and does steam undergo phase change?

This post was last edited by wiseboy on 2020-5-12 at 10:24. The description of this standard is: supercooled steam has condensed. Generally, it is calculated in two stages: condensation + supercooling (liquid cooling); theoretically, there are two heat transfer coefficients K. During the actual calculation, the degree of temperature drop in the cooled part is taken into account. If the supercooling is not significant, the supercooling section can be omitted; a slight margin can be added to the condensation section. If the supercooling is significant, calculation needs to be done in segments. The essence of segmented calculation is to calculate two heat exchangers and then connect them in series (add them together) to form one heat exchanger. Principle of segmented calculation: The following parameters for the two segments must be exactly identical: 1) Shell diameter ； 2) Piping ； 3) Number of pipe stages ； 4) Baffles (if any). Finally, add the lengths of the two sections of pipe together (which is equivalent to their areas). In other words, you can’t have a shell diameter of 800 in the condensation section and 600 in the subcooling section; that way, it’s not possible to create a heat exchanger. Many experts and professors have spent their entire lives working on heat exchangers and earning money from providing training; they teach people to use \"segmented calculation\" without even knowing this most basic principle.

I’ve learned it.* I would like to ask: if steam flows through the 8 tubes on the process side, but undergoes phase change around tube 5, could this cause blockages?

Blockages are bound to occur; therefore, condensation inside multi-pass tubes like yours is discouraged – almost no one does this. This is asking for trouble, and multiple tubes do not provide any improvement in condensation within the tubes; I’m not sure what theory underpins your choice of using multiple tubes for internal condensation.

It was a selection determined by someone else; they asked me to help design the structure, but I’m not very familiar with steam thermodynamic calculations, so I didn’t argue with them

If it is shell-side condensation, multiple tube sides have no impact； Do not use multiple tube passes for internal condensation.

Mm. Are you a developer at Vivi Technology?