How exactly is the duct routing constraint circle determined?
Thread Content
In fixed-tube-sheet heat exchangers, it is necessary to determine the tube layout boundary circle when arranging the tubes; but after using the formula Di-2b3=DL from GB151, why is it still necessary to subtract the diameter of one of the heat exchange tubes? Is the circle determined after such calculations correct? Why? I’m a beginner; I hope the more experienced members can give me some advice. Thank you!
The limiting circle is defined with respect to the outside of the heat exchange tube; by subtracting the diameter of the heat exchange tube from this value, we get a circle centered on it. When arranging the tubes, it is sufficient for the intersection points to lie within the diameter circle of the DL-pore diameter.
When arranging tubes in a fixed-tube-sheet heat exchanger, it is necessary to determine the tube arrangement limit circle. However, according to the formula Di-2b3=DL in GB151, the tube arrangement limit circle calculated represents the outer diameter of a circle; by subtracting the diameter of one of the heat exchange tubes from this value, what is obtained is the diameter of the circle formed by the centers of the outermost heat exchange tubes that can be arranged there.
I see, I understand now. Thank you to both seniors for your guidance!