Two exam questions on tube sheets
Thread Content
1. When U-tube sheet heat exchangers and fixed-tube-sheet heat exchangers use the type e connection configuration for the tube sheet with the shell and tube bank as specified in Figure 7-3 of GBT 151-2014, 1) For U-tube sheet heat exchangers under the sole influence of Pt(+), which of the following statements is correct? ( ) A. An increase in the flange torque on the shell side leads to an increase in the maximum stress in the tube sheet. B. A decrease in the flange torque on the shell side leads to a decrease in the maximum stress in the tube sheet. C. The maximum stress occurs at the center of the tube sheet. D. The maximum stress occurs at the edge of the tube sheet. 2. For U-tube sheet heat exchangers under the sole influence of Ps(+), which of the following statements is correct? ( ) (2.0 points) A. An increase in the flange torque on the shell side leads to an increase in the maximum stress in the tube sheet. B. A decrease in the flange torque on the shell side leads to a decrease in the maximum stress in the tube sheet. C. The maximum stress occurs at the center of the tube sheet. D. The maximum stress occurs at the edge of the tube sheet. Which one should be chosen? Why? Thank you all!
These issues relate to heat exchangers and the distribution of forces and moments. Regarding the moment distribution in the e-type connection configuration between the tube sheet, the shell, and the tube box for U-tube sheet heat exchangers and fixed tube sheet heat exchangers as shown in Figure 7-3 of GBT 151-2014: 1. For the case of U-tube sheet heat exchangers under the action of Pt(+) alone, choosing D should be the correct option. Because in this case, the stress on the tube sheet is concentrated mainly at the edges rather than at the center. This is because, in this structure, the connection points between the tube sheet and the shell and tube bank are located at the edges, resulting in the highest stress at those edges. 2. For the problem of the U-tube sheet heat exchanger under the sole action of Ps(+), the answer is also D. This is because the pressure on the tube sheet is primarily exerted by the shell, and in this case, due to the way the shell is connected to the tube sheet (the E-type configuration), the pressure applied by the shell is concentrated mainly at the edges of the tube sheet, resulting in the highest stresses at those edges. This is merely a possible answer derived from the design of heat exchangers and principles of mechanical engineering; it may need to be verified through actual engineering practice. These are also very specific mechanical problems; to obtain more accurate answers, the expertise of a structural mechanics specialist or an expert in heat exchanger design may be required. .
This post was last edited by prt0683 on 2023-11-8 09:23. Thank you for your replies; are both questions supposed to be answered with AD?