Hot water enters on the shell side and cools along the tubes. Why does the heat transfer coefficient decrease along the tubes and have a lower value at the water outlet? And why does the heat transfer coefficient decrease when the water inlet temperature decreases?
heat transfer coefficient is inversely proportional to length of the tube and temperature difference.
Please answer the question in detail. What physical variables and how they affect the heat transfer coefficient along tubes lenght.
TEMA, HEI, HEDH, ASME and many more textbooks, handbooks, standards, and countless published papers are available on the subject. A world of information is waiting for you to explore. I've already done that and I don't want to spoil the adventure for you.
Dear Malden,
The answer could be long and tedious, however, in brave it is called entrance region at the inlet, thermal boundary layer is initiated and it grows farther away from the inlet. The thermal boundary layers (T.B.Ls) are joined at a certain distance from the inlet known as the thermal entrance region. At this point, T.B.Ls act as barrier to heat to be transferred (Prandtl number plays important role here) and hence the rate of temperature decrease becomes lower.
Wish this helps Mladen Bošnjaković
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