Calculation method for steam heating of external coils in horizontal tanks
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There is currently an oily wastewater tank whose oil phase consists of C4 and C5 compounds. The owner wishes to increase the vaporization rate of the C5 component, and therefore plans to install heating coils on the outer wall of the tank; the heating medium will be superheated steam at 250°C and 1.0 MPa. Question: Are there any relevant standards for this type of design? How should the heat exchange area and steam volume be calculated? The standard I’m aware of, HG20570, is used for calculating heat retention, with saturated steam as the heat source ； The \"Design Manual for Oil Storage and Transportation\" applies to coil heating inside storage tanks, with saturated steam as the heat source. For designs involving external coil heating with superheated steam as the medium, which standards or manuals should be referred to for calculations? Thank you~
Can it be treated as a jacket (with the same area)?
This post was last edited by wiseboy on 2017-4-7 at 15:00. Adding a heating coil to the outside of the tank can certainly be calculated. However: 1. The efficiency is extremely low ； 2. A significant amount of heat (steam latent heat) is wasted: 1) When using a half-pipe, at least 61.10% of the steam’s heat is wasted. 2) More waste is incurred when using round tubes.
Thank you for your reply; I was busy these past few days and didn’t see it until now. What does a half-tube refer to? Also, is the amount of steam waste you’re referring to compared to using an internal coil for heating under the same conditions? Since the equipment does not have any extra ports, and the owner does not want to modify the pressure vessel, external coil steam heating is used. For this calculation, can the heat transfer coefficient be determined using the method for heat tracing specified in HG20570? As a result, the heat transfer coefficient is very low, less than 10 W/(m2·℃). Since the temperature that the medium to be heated needs to reach is not high, the calculated result shows that a small amount of steam is required; however, the heat exchange area is very large, to the point where it’s impossible to fit it around the exterior walls of the equipment. Is there any way to increase the heat transfer coefficient? (For example, by using thermal paste between the surrounding pipes and the equipment?) I don’t have any experience in this area either; it’s just a guess. I would appreciate your advice. By the way, the image is really cute
The heat transfer coefficients of the two should differ quite significantly, right? ?