Seeking help with the design of a tube heat exchanger
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I need to design a shell-and-tube heat exchanger. The hot side will have saturated steam at 0.77 Mpa, while the cold side will contain palm oil. The inlet temperature is 148 degrees, and the outlet temperature is 158 degrees. The flow rate is 150 t/h, with a density of 828.8 kg/m3. The designed flow velocity for this heat exchanger is 1.5 m/s. What value should be used for the heat transfer coefficient? I’m a beginner seeking advice; thank you to those who can help
The last edit to this post was made by wiseboy on 2016-1-28 at 16:30. The specification that the design flow velocity for this heat exchanger should be 1.5 m/s is an arbitrary and presumptive condition; in a heat exchanger, flow velocity is not a continuous variable. It could also be 1.3, 1.45, 1.66 – not quite reaching the 1.5 m/s you mentioned.
Thank you very much. Given that palm oil has a high viscosity, using this flow rate for calculation should work fine. So, given the conditions of the fluids on both sides of this heat exchanger, what value should be chosen for the heat transfer coefficient to be appropriate?
This post was last edited by wiseboy on 2016-1-29 at 10:41, version 1. The flow rates of the fluids on both sides together determine the two flow velocities on those sides; these two flow velocities need to be taken into account and influence each other ； However, the flow rates of the fluids on both sides need to be determined through thermal balance calculations ； 2. The correct heat transfer coefficient is always calculated, not taken directly. Taking it means shoddy workmanship ； 3. The flow rate and heat transfer coefficient are both related to the following two main factors: 1) The specific structural dimensions of the heat exchanger: (shell diameter, tube diameter, tube length, tube spacing, tube arrangement pattern, presence of baffle plates, material of the tubes,...) ； 2) Specific process data: 2 flow rates, 4 temperatures, physical properties (specific heat, density, viscosity, thermal conductivity) ； In short, comprehensive calculation and design are required. The shoddy method of \"taking\" is unacceptable today.