Questions regarding heat exchange area calculation
Thread Content
I’ve been studying books on *heat exchange area recently, and I encountered a basic question: the value marked with a question mark in the image, 4180, where does this number come from? Is it obtained by looking up a table or through calculation? If it’s a search, which edge table should be checked? If it’s a calculation, please list the calculation steps as well. Thank you.
The unit of the heat transfer coefficient is kcal/(㎡*h*℃); it’s not joules, right?
This is the heat transfer coefficient; the value given is a reference value, and an accurate calculation is required!
The Q value is in KJ/h, and K should also be in KJ/
4180 is the estimated value for K
That K is the heat transfer coefficient, which is related to the structure of the heat exchanger, the medium used, as well as the material and thickness of the heat transfer tubes. In some industries, estimated values are used, while in others a comprehensive calculation taking into account the structure, the medium, and the flow rate is employed; these calculations are quite complex. The estimated values or those taken from tables are all empirical values.
This post was last edited by wiseboy on 2021-12-6 at 11:59. This 4180 is the overall heat transfer coefficient. However, it seems to be fabricated data, and the quality of fabrication is particularly poor. The core of heat exchanger calculations is to compute this value, rather than fabricating such data.
I agree with you; this number is too high
Someone actually reads books like this. Leading people astray.
This book contains many unreasonable figures; many of these numbers appear without any reason and have no basis in reality. This value of 4180 is the heat transfer coefficient, and it’s far too high