Heat exchanger calculation
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I would like to ask everyone: can the actual heat fluxes of the hot and cold fluids in a heat exchanger differ significantly? In my calculations, I found that in some cases the difference was as much as 3 times. I only took temperature into account, without considering pressure; moreover, it’s not possible to measure the pressure either. This applies to distillation and vacuum distillation heat exchange processes
Also, normally what is calculated is the efficiency of the heat exchanger; there’s no such thing as heat loss in a heat exchanger, right?
Under normal conditions, there is always heat loss; only in an ideal state is there no heat loss
This post was last edited by Qingcheng Jun on 2023-2-7 at 10:33. From your description, it seems like you’re not good at calculating. First, find some books or papers to look up the calculation formulas for heat exchangers
It can’t be that big, unless your data traffic is extremely low and the heat loss is very high
It’s impossible; even basic energy conservation can’t be satisfied
I heard high-level professionals say, “Science is cold.” Wisdom is warm.” Science is indeed cold; what it can’t do, it simply can’t do; what’s wrong, is wrong. No matter how high your emotional intelligence is or how good you are at building relationships, it’s of no use in the face of science
I don’t fully understand what you mean; it’s common for the actual flow rates of cold and hot fluids, as well as the heat transfer amount, to differ from those specified in the design. To assess the actual operating conditions of the heat exchanger, it is necessary to measure the inlet and outlet temperatures and flow rates. It is common for there to be a mismatch with the designed flow rate and heat transfer capacity if the pipe resistance is not properly calculated, or if there is branching of the hot and cold fluids before they enter the heat exchanger
There is usually a certain difference between theory and practice; a difference of 10% to 20% is possible. If the difference is three times as large, then there is definitely an issue with the calculations – either certain conditions on site were overlooked, or the formulas were used incorrectly.