【Q&A Question 208】2017.07.27
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【Q&A Question 208】July 27, 2017: Why does a heat exchanger achieve good heat transfer at first but its performance gradually deteriorates over time? The reference answer can be seen after responding; scoring is possible by identifying the key points. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) During the operation of the heat exchanger, deposits gradually accumulate on the inner and outer surfaces of the tubes, which reduces the overall heat transfer coefficient and thus leads to a gradual decline in the heat exchange efficiency. Scoring criteria: 2 Wealth points for incorrect attempts; 3–8 points for *incomplete* answers. 10 Wealth points for correct answers, provided along with a detailed explanation; 15–20 Wealth points for correct answers with additional *insufficient* details. Please score according to these criteria. Note: If there are editing records after answering, only those who participated will be credited points. For continuous malicious spamming, 2 points will be deducted each time, with no upper limit. Pure numbers, pure emojis, or random letters unrelated to the answer are all considered malicious spamming; points will start to be deducted after three warnings. 2017 Q&A Summary Thread (updates have begun) http://bbs.hcbbs.com/thread-1657793-1-1.html 2017 Daily Question Summary Thread (updates have begun) http://bbs.hcbbs.com/thread-1657794-1-1.html 2016 Q&A Summary Thread (updates completed) http://bbs.hcbbs.com/thread-1597792-1-1.html Petrochemical Zone – “Creative Ideas for Energy Savings” campaign (the second phase is in full swing) http://bbs.hcbbs.com/thread-1666758-1-1.html (Source: Haichuan Chemical Industry Forum Website)
During operation, the heat exchanger gradually accumulates deposits on the inner and outer surfaces of its tubes (such as sludge, coking, salts, etc.). These scale formations are generally loose and porous substances with a low thermal conductivity, which increases the thermal resistance and thus reduces the overall heat transfer coefficient; as a result, the heat exchange efficiency deteriorates over time.
The increasing scaling on the inner and outer walls of the pipe reduces the heat transfer coefficient
Scale and rust accumulation inside the heat exchanger reduce its heat exchange area
It is mainly the scaling on the process side and the cooling or heating side that results in poor heat exchange efficiency
Scaling of the heat exchanger, and blockage of some tubes after a leak occurred in the heat exchanger
During operation of the heat exchanger, deposits gradually accumulate on the inner and outer surfaces of the tubes, reducing the overall heat transfer coefficient and thus causing the heat exchange efficiency to decline over time.
During operation of the heat exchanger, deposits such as sludge, scale, coking, and rust gradually accumulate on the inner and outer surfaces of the tubes. These deposits are usually loose and porous substances with a low thermal conductivity, which reduces the overall heat transfer coefficient and thus leads to a gradual decline in the heat exchange efficiency.
During operation of the heat exchanger, deposits such as sludge, scale, coking, and rust gradually accumulate on the inner and outer surfaces of the tubes. These deposits are usually loose and porous substances with a low thermal conductivity, which reduces the overall heat transfer coefficient and thus leads to a gradual decline in the heat exchange efficiency.