【Q&A Question 006】2018.01.06
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This post was last edited by liuquan1100 on 2018-1-6 at 11:20. [Q&A Question 006] How to control the rate of temperature increase and decrease during the start-up and shutdown of hydrogen production units? 2018.01.06 During startup and shutdown, rapid temperature changes can cause significant damage to both the equipment and the catalyst. The furnace tubes expand and contract rapidly when exposed to heat or cold, and these thermal stresses can easily lead to thermal fatigue cracks, thereby damaging the furnace tubes or reducing their service life. The furnace walls may also develop cracks or even collapse. The catalyst, too, suffers from wear or destruction due to intense expansion and contraction. Therefore, during startup and shutdown, a certain rate of temperature increase is generally maintained, with a target range of 25–30°C per hour. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) For management purposes, if you need to view content from a few days ago, please go through the summary post below. Summary post of daily questions on hydrogen production and hydrogenation technologies for 2018: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888971Summary post of daily images on hydrogen production and hydrogenation technologies for 2018: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888970
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This post was last edited by “The Moon in My Hometown is Round” on January 6, 2018, at 11:20. How to control the rate of temperature rise and fall during startup and shutdown? Answer: During startup and shutdown, rapid temperature changes can cause significant damage to both the equipment and the catalyst. The furnace tubes expand and contract rapidly when exposed to heat or cold, and these thermal stresses can easily lead to thermal fatigue cracks, which may damage the furnace tubes or reduce their service life. The furnace walls can also develop cracks or even collapse. The catalyst, too, suffers wear or destruction due to intense expansion and contraction. Therefore, during startup and shutdown, a certain rate of temperature increase is usually controlled, with a target range of 25–30°C/h.
The rate of temperature change should not exceed 30 degrees Celsius per hour.
Generally controlled at 25~30°C per hour
During startup and shutdown, rapid temperature changes can cause significant damage to both the equipment and the catalyst. The furnace tubes expand and contract rapidly when exposed to heat or cold, and these thermal stresses can easily lead to thermal fatigue cracks, thereby damaging the furnace tubes or reducing their service life. The furnace walls may also develop cracks or even collapse. The catalyst, too, suffers from wear or destruction due to intense expansion and contraction. Therefore, during startup and shutdown, a certain rate of temperature increase is generally maintained, with a target range of 25–30°C per hour.
During startup and shutdown, rapid temperature changes can cause significant damage to the equipment and catalysts. The furnace tubes expand and contract rapidly when exposed to heat or cold, leading to sharp changes in thermal stress; this makes it easy for thermal fatigue cracks to form, which can damage the furnace tubes or reduce their service life. The furnace walls may also develop cracks, or even collapse. The catalyst also suffers wear or fragmentation due to intense expansion and contraction. Therefore, during startup and shutdown, a certain range of temperature rise and fall rate should be controlled, generally between 30 and 50°C/h.
During startup and shutdown processes, too rapid heating or cooling can cause significant damage to both the equipment and the catalyst. The furnace tubes experience rapid heating and cooling, leading to changes in thermal stress; this makes it easy for thermal fatigue cracks to form, which can damage the furnace tubes or reduce their service life. The furnace walls may also develop cracks or even collapse. The catalyst, due to intense expansion and contraction, can become worn out or crushed. Therefore, it is necessary to control the rate of heating and cooling during these processes, with a target rate of 25–30°C per hour.
During startup and shutdown, a certain rate of temperature change must be controlled, generally kept at 25–30°C/h (≯50°C/h).
During startup and shutdown, rapid temperature changes can cause significant damage to both the equipment and the catalyst. The furnace tubes expand and contract rapidly when exposed to heat or cold, and these thermal stresses can easily lead to thermal fatigue cracks, thereby damaging the furnace tubes or reducing their service life. The furnace walls may also develop cracks or even collapse. The catalyst, too, suffers from wear or destruction due to intense expansion and contraction. Therefore, during startup and shutdown, a certain rate of temperature increase is generally maintained, with a target range of 25–30°C per hour.