AC Area of Heat Exchanger Equipment – One Question per Day, 2011.5.7
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This post was last edited by chenyu*a on 2011-5-9 09:16. Please hide your replies; think carefully before posting, as edits are invalid! Those with different views on the provided answer keys can post discussions the next day. For multiple accounts under the same IP responding to participate, only the first response is considered valid. The minimum reward for participants is 2 points, while those who answer correctly receive 5 points; higher rewards are given if the answers are detailed and accurate. Please hide your replies – the method for doing this is: http://bbs.hcbbs.com/thread-492556-1-1.html. Which of the following heat exchangers may require a temperature difference compensation device when there is a large temperature difference? ( ) (a) Packing box type heat exchanger (b) U-tube type heat exchanger (c) Floating head type heat exchanger (d) Fixed tube sheet type heat exchanger. Answer: D
Generally, when the temperature difference between the tube wall and the shell wall is 50°C or more, a temperature difference compensation device should be installed in the heat exchanger for safety reasons. However, compensation devices (expansion joints) can only be used when the temperature difference between the shell wall and the tube wall is below 60–70°C and the pressure of the fluid in the shell side is not high. Generally, when the shell-side pressure exceeds 0.6 Mpa, the compensation ring becomes too thick and is unable to expand or contract, thereby losing its function of compensating for temperature differences; in such cases, other designs should be considered
(d) Fixed tube sheet heat exchanger
(d) Fixed tube sheet heat exchanger