【Daily Question】 【AC Version for Static Equipment...Question 57】 February 26, 2019 – Match the items...Everything is going well

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This post was last edited by kareale88 on 2019-2-26 08:30: bg14.jpg【Daily Question】【AC version for static equipment...Question 57】 February 26, 2019. Multiple-choice questions with matching options...Everything is going well...........................................................................Answering rules: Single-choice answers should be entered in the blanks, one after another in order. Reward rules: 2 Wealth for participation, 2 Wealth for each correct answer, up to a maximum of 10 Wealth. Test results: The significance of multiple-choice questions is to foster interest in essay questions and reduce aversion toward them. ........................................................................... Final voting stage for the 2018 “Top 10 Outstanding Members of Haichuan” – only available via Haichuan’s official WeChat account! For more details, please see the link below: https://bbs.hcbbs.com/thread-2281360-1-1.html. A big thank you to all my supporters from the region—voting is open for candidates No. 28 (@泡沫_ZPTK), No. 29 (@kareale88), No. 30 (@亚梅), and No. 31 (@梦幻100). After voting, you can participate in a lottery for prizes such as laptops, Haichuan Cup awards, phone credit, and 100 Wealth points... You can vote and enter the lottery up to 10 times per day... Hurry up and participate! ........................................................................... 1. Under what combined loads might a fixed tube-sheet heat exchanger fail to meet strength requirements, thereby necessitating the use of other types of heat exchangers (such as U-tube type)? Answer: Under very high (1) pressure and significant combined effects in the tube side and shell side (2), fixed-plate heat exchangers may fail to meet the strength requirements. To reduce the large (3), it is necessary to install (4), but this in turn causes the tubes and tube sheets to experience extremely high (1) pressures, leading to significant (5) that prevents them from meeting the strength requirements; therefore, other types of heat exchangers are chosen. A. Pipe stage ； B. Thermal stress ； C. Expansion joint ； D. Stress ； E. Temperature difference load ； ---------------------Answers: 1. A 2. E 3. B 4. C 5. D. Answer: Under the combined effect of very high tube side pressure and large temperature differences between the tube side and shell side, fixed-head heat exchangers cannot meet the strength requirements. To reduce the large temperature difference stress, expansion joints must be installed; however, this in turn causes the pipes and tube sheets to experience extremely high stresses under high pressure in the tube side, preventing them from meeting the strength requirements. Therefore, other types of heat exchangers are chosen. 1. Comments: This question relates to the selection of heat exchange equipment and is an optional question. The title refers to the basic considerations for selecting heat exchangers in terms of structural and strength design; by understanding the fundamental principles of stress distribution in fixed-tube-sheet heat exchangers, this issue becomes easily solvable.