Two issues encountered while using HTRI V7.3.2 – please ask an expert for help
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Question 1: In htri, under Baffles and then Supports, there are two settings related to U-bends; one is full support at U-bend (with options of Yes and No)； The other one is U-bend supports, and the number of these can range from 0 to 5. My question is: what is the difference between these two options? Are these two options the same thing? Do I just need to choose one of them, or do I need to set both of them – are they not the same thing? Where are the U-bend supports here, and if there are five supports, how are they distributed? Question 2: What is the difference in function between \"Fill passlane with dummy tubes\" in Tube Layout and \"passlane seal device\" in Bundle Clearences? I understand that the latter is used to block the F Stream, that is, it blocks the F Stream parallel to the flow direction on the shell side of multi-pass systems; whereas the dummy tubes in the former are used to fill the gaps between the tubes, and it seems like their functions are the same. Please, an expert, explain it to me! Thank you so much!
I’m waiting urgently for a reply; I hope someone experienced can give me some advice
Ask yourself the question: I tested the second issue. A dummy tube and a seal rod are the same thing, as can be seen from the percentage represented by F Stream. However, one difference is that the diameter of the dummy tube in the case of seal rods can be customized, while a dummy tube must have the same diameter as the heat transfer tube. In other words, if the diameter of the seal rod matches that of the heat transfer tube, then it’s no different from a dummy tube； If the seal rod specifies its own diameter, the impact on the proportion of F Stream will change, and this change should be determined based on the shell-side pressure drop and whether the proportion of F Stream is low enough. Regarding the first question, the expert in heat exchangers at my previous employer explained that for U-tube heat exchangers with a shell diameter of less than 1300 mm, full support is generally used in domestic designs; however, when the diameter is greater than 1300 mm, full support is not recommended, and instead special support is needed – in such cases, U-bend supports should be used, with the number of supports specified on a scale from 0 to 5.
My understanding is as follows: Question 1: In the Baffles section of htri, there are two settings related to U-bends; one is full support at U-bend (with options of Yes and No)； For the full support plate at the tail of the U-tube, select the tangent position; for the nozzle position, choose \"Before\". The other one is the U-bend supports: this plate is used to resist vibrations, and it is placed at the U-tube location to increase the vibration frequency. Question 2: What is the difference in function between \"Fill passlane with dummy tubes\" in Tube Layout and \"passlane seal device\" in Bundle Clearences? The understanding is correct. Both are used to prevent F-flow leakage; literally, one is a fake tube and the other is a solid rod. Other slats and the like can also be used; they serve the same purpose. Specific functions: HTRI provides some default or custom settings in both locations.