Minor issue with the heat exchanger

Let’s try an explanation from a certain counterfeit source:P See if this way of understanding works: first, open the end caps of the shell-and-tube heat exchanger and check its length. Determine how many tubes are present in the cross-section along this length; by calculating the cross-sectional area of each tube and multiplying it by the number of tubes, you should get the \"area at the inlet and outlet of the tube bundle\". Then pull out the tube bundle to check if there are baffles; if not, the \"area of the shell inlet and outlet\" should be calculated by subtracting the sum of the external diameter areas of each tube column multiplied by the number of tubes from the internal area of the cooler shell. For those with baffle plates, that portion must be subtracted from this amount; only the remaining value represents the total area. Hehe, in the end, it all comes down to choosing the nominal diameter of the pipes for imports and exports. I’m not sure if I explained it clearly. Pirate languages; P

I understand what you mean, but it seems a bit different from the calculations in Appendix J of GB151. Still, thank you so much!

Shell inlet: The fluid flows through the nozzle and then enters the area within the shell where it spreads out; this area has a saddle-shaped interface (related to the height of the first row of tubes and whether there is any anti-erosion protection). This can be calculated by referring to GB/T151 J.1. Area at the inlet and outlet of the tube bundle: The flow area in the first span of the tube bundle (depends on the distance between the first baffle plates, the presence of anti-scour measures, and the direction of the cuts); this can be calculated by referring to GB/T151 J.2.