(Daily Question) Coal-to-oil and olefins forum, 3/24/2018

Not only do the aforementioned hazards arise from surge, but it also disrupts the balance of the entire system; therefore, operators must make timely judgments and take appropriate actions. Surge can usually be detected through the following methods: 1. Listening to sounds – When the compressor is approaching surge conditions, periodic noises can be heard in the exhaust pipeline. When entering the surge condition, noise increases rapidly, and even a roaring sound may occur; if the noise level rises, it is very likely that surge is taking place. 2. Check the instruments: One characteristic of surge is a reduction in airflow, along with periodic fluctuations in that airflow. At such times, it is possible to observe significant swings in the pointers of the flow meter and pressure gauge; by observing these movements, it can be determined whether surge is occurring.

1. Judgment based on the noise of the airflow in the outlet pipeline. Periodic \"hissing\" sounds generally occur when the compressor is approaching the surge condition; once surge occurs, the noise increases significantly and can be easily detected. 2. Judge based on changes in outlet pressure and flow rate. When the measuring instrument experiences large-scale and periodic fluctuations, it is possible to judge based on the movement of the pointer as well as the vibration of the machine body and bearings; at such times, the amplitude of these vibrations increases significantly, and the machine body vibrates more intensely.

Determining compressor surge: (1) Listen to the noise of the airflow in the compressor’s outlet pipe. Under stable operating conditions, a centrifugal compressor produces low-level, continuous noise. However, as it approaches surge conditions, periodic oscillations of the airflow throughout the system cause the noise level in the outlet pipe to fluctuate up and down. Once surge conditions are reached, the noise level increases significantly, and even explosive noises may occur. (2) Observe the changes in the compressor’s outlet pressure and inlet flow rate. When operating under stable conditions, the changes in these values are minimal, with small fluctuations in the measured data. As the compressor approaches or enters surge conditions, these values experience large, periodic fluctuations; sometimes, gas can even be pushed back out from the compressor’s inlet. (3) Monitor the vibration of the compressor housing and bearings. When approaching or entering surge conditions, both the housing and bearings experience intense vibrations, with amplitude levels that are higher than during normal operation.

1. Judgment based on the noise of the airflow in the outlet pipeline. Periodic \"hissing\" sounds generally occur when the compressor is approaching the surge condition; once surge occurs, the noise increases significantly and can be easily detected. 2. Judge based on changes in outlet pressure and flow rate. When the measuring instrument experiences large-scale and periodic fluctuations, it is possible to judge based on the movement of the pointer as well as the vibration of the machine body and bearings; at such times, the amplitude of these vibrations increases significantly, and the machine body vibrates more intensely.

1. Measure the noise of the airflow in the compressor outlet pipeline. Under stable operating conditions, centrifugal compressors produce low-level, continuous noise. However, as they approach the surge condition, periodic oscillations of the airflow within the entire system cause the noise generated by the airflow in the outlet pipe to vary in intensity, showing periodic fluctuations. Once surge conditions are reached, the noise level increases sharply, and even explosive noises may occur. 2. Observe the changes in the compressor outlet pressure and inlet flow rate. When a centrifugal compressor operates under stable conditions, the changes in its outlet pressure and inlet flow rate are minimal, with very small variations in the measured data. When approaching or entering the surge condition, both of them experience significant changes, with periodic large-amplitude fluctuations; sometimes it is even possible to observe gas being pushed back out from the compressor inlet. 3. Observe the vibration of the machine body and bearings.

Answer: Observe the changes in pressure and flow rate at the compressor outlet； Listen to the changes in the noise from the compressor outlet flow channel ； Observe the vibration of the machine and bearings.

(1) Measure the noise of the airflow in the compressor outlet pipeline. Under stable operating conditions, centrifugal compressors produce low levels of noise and... (2) Observe the changes in the compressor’s outlet pressure and inlet flow rate. When a centrifugal compressor is operating under stable conditions, its output... (3) Observe the vibration of the casing and bearings.

(1) Measure the noise of the airflow in the compressor outlet pipeline. Under stable operating conditions, centrifugal compressors produce low-level, continuous noise. However, as they approach the surge condition, periodic oscillations of the airflow within the entire system cause the noise generated by the airflow in the outlet pipe to vary in intensity, showing periodic fluctuations. Once surge conditions are reached, the noise level increases sharply, and even explosive noises may occur. (2) Observe the changes in the compressor outlet pressure and inlet flow rate. When a centrifugal compressor operates under stable conditions, the changes in its outlet pressure and inlet flow rate are minimal, with very small variations in the measured data. When approaching or entering the surge condition, both of them experience significant changes, with periodic large-amplitude fluctuations; sometimes it is even possible to observe gas being pushed back out from the compressor inlet. (3) Observe the vibration of the machine body and bearings.

Determining compressor surge: (1) Listen to the noise of the airflow in the compressor’s outlet pipe. Under stable operating conditions, a centrifugal compressor produces low-level, continuous noise. However, as it approaches surge conditions, periodic oscillations of the airflow throughout the system cause the noise level in the outlet pipe to fluctuate up and down. Once surge conditions are reached, the noise level increases significantly, and even explosive noises may occur. (2) Observe the changes in the compressor’s outlet pressure and inlet flow rate. When operating under stable conditions, the changes in these values are minimal, with small fluctuations in the measured data. As the compressor approaches or enters surge conditions, these values experience large, periodic fluctuations; sometimes, gas can even be pushed back out from the compressor’s inlet. (3) Monitor the vibration of the compressor housing and bearings. When approaching or entering surge conditions, both the housing and bearings experience intense vibrations, with amplitude levels that are higher than during normal operation.

Observe the changes in compressor outlet pressure and flow rate； Listen to the changes in the noise from the compressor outlet flow channel ； Observe the vibration of the machine and bearings.