Study On Hydraulic Decoking Progress On-line Monitoring Using Optical Fiber Sensing Technology

In petrochemical industry, delayed coking is an important production process. Currently delayed coking unit in hydraulic decoking process generally rely on the operator through the voices and the concept of water towers the chute bottom of coke to judge coke clean. Subject to the restrictions of the operating conditions, weather factors, the impact of the cut coke process to accurately determine. Conventional electric sensors due to the inherent characteristics, such as a short life cycle, and are vulnerable to many of the problems of electromagnetic interference, and is not suitable for online monitoring of the hydraulic decoking process. Therefore, in this area, yet a safe and reliable method can be used to and hydraulic monitoring online. It is necessary to develop a system used for online monitoring hydraulic decoking progress which is suitable for the coking environment.This study on optical fiber sensing technology for hydraulic decoking progress on-line monitoring. In the study, explosion-proof, resistance to electromagnetic interference, easy networking distributed measurement and other unique advantages of optical fiber sensor were made full use of. The sensors were installed in the right position of the coke tower and monitoring experiment was completed. The preliminary results have been achieved. The main content of the article is as follows:1. Hydraulic decoking background, research status at home and abroad of hydraulic decoking monitoring technology and the significance of optical fiber sensing technology for hydraulic decoking monitoring were introduced.2. According to the characteristics of hydraulic decoking, fiber grating vibration sensor and fiber optic F-P acoustic sensor were chosen to monitor hydraulic decoking process. The principle of the two kinds of sensors were described. In order to satisfy the actual requirement, the structure of the sensors were improved, and the parameters of the sensors was analyzed.3. According to the experiment scheme, the sensors were installed in different positions of the coke tower and were connected to the demodulation equipments in the control room. Then4. The vibration data and acoustic data obtained in decoking process monitoring experiment were analyzed by using the method of spectrum analysis. Based on the spectral information of the vibration signals and acoustic signals during different periods of the decoking process, the coke in the tower was cleared or not could be deduced. Studies have shown that using fiber-optic sensing system can automatically detect the hydraulic inter coke the coke tower coke clearance, reduce labor intensity, improve automation level of real-time monitoring, shorten cut coke cycle, improve work efficiency, reduce energy consumption, and enhance operational safety of hydraulic decoking system.