Software application for water bath vaporizer
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I have just designed a water bath vaporizer. The design parameters are as follows: the heating source is 120-degree circulating hot water, the operating temperature is 70 degrees (heat source side, normal pressure), and the cold fluid is pure liquid nitrogen (-1) with a flow rate of 2000Kg/h (8.1MPa). 96 degrees), after heating it is saturated nitrogen at 50 degrees, the heat exchange tube material is 0Cr18Ni9 (nitrogen flows inside the tube), and the heat exchange area is manually calculated to be 20 square meters. However, experienced colleagues said that the heat exchange area is 30% less, I don’t know if that is correct! I don’t know if this type of tube-wound vaporizer (the heat exchange tube is a tube-wound, with a length of 15 to 18 meters) can be calculated in htfs+2006. If so, could any experts please demonstrate it? Thank you!
There should be no way to simulate it in software. How big is the heat transfer coefficient you calculated?
Back to my brother on the 2nd floor, I calculated three sections by hand: 1. Liquid nitrogen heating section, K=110W/m2.K; 2. Liquid nitrogen vaporization section, K=55W/m2.K; 3. Gas nitrogen heating section, K=150W/m2.K; I have an idea: If the inlet and outlet manifolds at both ends of the gas section of the heat transfer tube are assumed to be tube sheets, that is, the carburetor is assumed to be a simple shell-and-tube heat exchanger, can tasc+ be simulated in htfs+2006? Thanks!
1 "The heating source is 120-degree circulating hot water, and the operating temperature is 70 degrees (the heat source is taken away from the shell side, normal pressure)." I don't understand what it means. There is no 120-degree liquid water under normal pressure. 2 The heat transfer coefficients in the stages you gave do not seem to be right. Generally, the heat transfer coefficient in a process with phase change will be larger than that of a pure phase, but yours is the smallest. 3 tasc+ simulation of this situation should still be very different, and the empirical heat transfer coefficient is the most accurate.
Generally, the heat transfer coefficient of the outer film of a tube should be calculated based on natural convection. The heat transfer software only calculates the forced convection or forced laminar film heat transfer coefficient caused by the main flow, so it may be low.
Water bath gas vaporizer heat exchange area calculation hot side (water): Medium flow: 30000Kg/h (flowing) specific heat capacity : 4.2KJ/Kg * ℃ inlet temperature: 22℃ outlet temperature: 18.8 (calculation) Heat transfer : 112KW cold side (co2): Medium flow: 1000Kg/h specific heat capacity : 0.96KJ/Kg * ℃ heat of vaporization : 360KJ/Kg inlet temperature: -30 outlet temperature: 15 heat exchange : 112KW calculated average logarithmic temperature difference≈21 degrees Celsius ； Assume that the heat transfer coefficient is that of water to air, which is 6-18W/㎡·℃ (because I don’t know if this coefficient is correct for the liquid CO2 when it is imported) ； The calculated heat exchange area is several hundred square meters. I feel that the calculation is wrong. Please give me some advice.
Please tell me how to calculate by hand for water bath heat exchanger