【Q&A】Catalytic Coking Reformate Blending Version 20170921
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This post was last edited by Green Lotus on 2017-9-20 at 17:47. Participants: Reward of 5 Wealth； Correct answer: Reward of 10 wealth points ； Note: This post is valid for 48 hours. Question: What is the phenomenon of surge? Answer: a. The unit vibrates heavily, and there are surging noises at the inlet and outlet ； b. The compressor outlet pressure fluctuates rapidly ； c. Main motor current fluctuations ； d. Increase in inlet temperature. Move your fingers and get involved; our ultimate goal is for everyone to acquire knowledge. http://bbs.hcbbs.com/static/image/hrline/1.gif http://bbs.hcbbs.com/static/image/hrline/2.gif The answers will be announced automatically in two days. Petrochemical Zone – “Creative Ideas for Energy Saving”: The second phase of this activity is currently in full swing. http://bbs.hcbbs.com/thread-1666758-1-1.html [Daily Question] Summary post for 2017 on the blending of catalytic coking and reforming oils. http://bbs.hcbbs.com/thread-1811219-1-1.html [Q&A] Summary post for 2017 on the blending of catalytic coking and reforming oils. http://bbs.hcbbs.com/thread-1826018-1-1.html
a. The unit experiences high vibration, with surge shock noises at the inlet and outlet； b. The compressor outlet pressure fluctuates rapidly ； c. Main motor current fluctuations ； d. Increase in inlet temperature
The low-frequency, high-amplitude oscillations of the airflow along the compressor axis are known as surge
a. The unit experiences high vibration, with surge shock noises at the inlet and outlet； b. The compressor outlet pressure fluctuates rapidly ； c. Main motor current fluctuations ； d. Increase in inlet temperature
Fluctuations in flow rate, abnormal noises from the unit, increased vibration
Centrifugal compressors experience severe vibration in their casing due to low inlet pressure or low flow rate.
Surge is a type of abnormal vibration that occurs in turbine compressors (also known as vane compressors) when the flow rate decreases to a certain level. A centrifugal compressor is a type of turbine compressor, and surge poses a serious threat to centrifugal compressors.
Compressor surge is a phenomenon of low-frequency, high-amplitude oscillations in the airflow along the compressor axis. This type of airflow oscillation with low frequency and high amplitude represents a significant source of excitation forces; it can cause severe mechanical vibrations in the engine components as well as overheating at the hot ends, leading to serious damage to these components in a very short time. Therefore, it is not allowed for the compressor to operate in the surge zone under any circumstances. Phenomena during surge: the engine sound changes from a high-pitched whine to a low sound ； The vibration of the engine has increased ； Significant fluctuations in total pressure and flow rate at the compressor outlet ； The rotation speed is unstable, the thrust drops suddenly, and there are significant fluctuations ； The exhaust temperature of the engine rises, resulting in overheating ； In severe cases, detonation occurs, the airflow is interrupted, resulting in engine shutdown. Therefore, once the above phenomenon occurs, immediate action must be taken to bring the compressor out of a surge condition.
The machine vibrates violently and makes a roaring noise; its operation is extremely unstable
The phenomenon of unstable, periodic fluctuations in flow rate occurring in an instant. When the rotational speed remains constant, the flow rate of gas entering the compressor decreases to a certain level, resulting in uneven gas velocities within the blade channels as well as backflow. When this phenomenon spreads throughout the entire blade channels, the gas cannot flow out, causing a sudden drop in pressure within the compressor stage. The relatively higher pressure downstream forces the gas to flow back into the stage, after which the pressure within the stage returns to normal and the impeller resumes its normal operation, pushing the backflowing gas outward again. Thereafter, the pressure in the stage dropped suddenly again, and the airflow flowed back; this phenomenon repeated itself, causing the compressor to operate unstably. This phenomenon is known as surge.