[Q&A Question 080] 2018.03.21
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【Q&A Question 080】March 21, 2018: Briefly describe the possible phenomena that may occur if the reaction injection water is interrupted After the interruption of the reactive injection water, the following occurred: the inlet and outlet temperatures of the high-pressure air cooler increased ； The flow rate due to external desalination and water deoxygenation stops at zero; the liquid level indicator in the water injection tank drops ； Injection water supply is interrupted; the injection volume decreases or reaches zero, the injection pump shuts down due to interlock, and the high-level interface indicator drops ； ③The concentrations of NH3 and H2S in the circulating hydrogen increase ； ⑤Prolonged cessation of water supply can cause the air-cooled ammonium salts to precipitate and become clogged, increasing the system pressure drop. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) Due to the limits on the number of posts in the “One Question per Day” section, “One Image per Day” has been moved to the registered devices section; you can access it through the directory I posted. For management purposes, if you need to access content from a few days ago, please go to the summary post below to enter the “My Registration Season” event – (Note: This event is currently underway in the Chemical Engineering section). https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=18978 For the daily questions section related to chemical engineering technology training in 2018: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888971 For the daily image section related to registered equipment in 2018: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888970 For the Q&A section related to hydrogen production and hydrogenation technologies in 2018: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888968 For the daily questions section related to LNG technology in 2018: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888973 For the Q&A section from 2017 (updates have started): https://bbs.hcbbs.com/thread-1657793-1-1.html For the daily questions section from 2017 (updates have started): https://bbs.hcbbs.com/thread-1657794-1-1.html For the daily image section from 2017: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1875160 For the list of daily questions related to LNG in 2017: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1804162 For the Q&A section from 2016 (all updates completed): https://bbs.hcbbs.com/thread-1597792-1-1.html
After the interruption of the reactive injection water, the following occurred: the inlet and outlet temperatures of the high-pressure air cooler increased； The flow rate due to external desalination and water deoxygenation stops at zero; the liquid level indicator in the water injection tank drops ； Injection water supply is interrupted; the injection volume decreases or reaches zero, the injection pump shuts down due to interlock, and the high-level interface indicator drops ； ③The concentrations of NH3 and H2S in the circulating hydrogen increase ； ⑤Prolonged cessation of water supply can cause the air-cooled ammonium salts to precipitate and become clogged, increasing the system pressure drop.
This may lead to excessively high temperatures after air cooling, as well as liquid in the circulating hydrogen, thereby affecting the proper operation of the compressor.
The inlet and outlet temperatures rise, the water injection flow rate is 0, and the concentrations of H2S and NH3 in the circulating hydrogen increase
After the interruption of the reactive injection water, the following situations occur: ① The inlet and outlet temperatures of the high-pressure air cooler increase； ②External water supply interrupted; the liquid level indicator in the water injection tank drops ； Injection is interrupted, the injection volume decreases or returns to zero, and the high-level interface indicator drops ； ③The concentrations of NH3 and H2S in the circulating hydrogen increase ； ④The reaction temperature drops ； ⑤Prolonged cessation of water supply can cause the air-cooled ammonium salts to precipitate and become clogged, resulting in an increase in system pressure drop. Handling: ① If the injection pump stops operating, immediately close the outlet valve of that pump to prevent high pressure from leaking into the low-pressure system, and start the backup pump right away while keeping the high-level cut-off point under control ； ②Water supply is interrupted; contact the upstream facility to supply water promptly ； ③If water supply is interrupted for a long time, reduce the feed or stop feeding it.
Answer: After the injection of reaction water is interrupted, the following occurs: the inlet and outlet temperatures of the high-pressure air cooler increase； The flow rate due to external desalination and water deoxygenation stops at zero; the liquid level indicator in the water injection tank drops ； Injection water supply is interrupted; the injection volume decreases or reaches zero, the injection pump shuts down due to interlock, and the high-level interface indicator drops ； ③The concentrations of NH3 and H2S in the circulating hydrogen increase ； ⑤Prolonged cessation of water supply can cause the air-cooled ammonium salts to precipitate and become clogged, increasing the system pressure drop.
The inlet and outlet temperatures rise, the water injection flow rate is 0, and the concentrations of H2S and NH3 in the circulating hydrogen increase
A short interruption in the reactive injection water has no impact on production, while a long interruption does have an impact. When the water injection is interrupted, the inlet temperature of the third-stage high-pressure heat exchanger rises, and the level of the cold high-pressure liquid also drops rapidly; it is important to control this liquid level to prevent high pressure from leaking into the low-pressure system. The cold low-solubility phase descends rapidly.
The heat exchange efficiency of high-pressure air cooling deteriorates