DNA Computing Based Genetic Algorithm by Jili Tao & Ridong Zhang & Yong Zhu

Author:Jili Tao & Ridong Zhang & Yong Zhu
Language: eng
Format: epub
ISBN: 9789811554032
Publisher: Springer Singapore

6.2 The Coke Unit

The whole process flow is shown in Fig. 6.1. It consists of such equipment as one fractionating tower (T102), three coke furnaces (F101/1, 2, 3), and six coke towers (T101/1, 2, 3, 4, 5, 6). The detailed flow of each part of the unit is shown in Fig. 6.2, its main job is to coke residual oil. Take furnace (F101/3) as an example, the process flow is as follows: The flow of residual oil is divided into two branches (FRC8103, FRC8105) and sent into the convection chamber of the furnace (F101/3) to be heated to about 330 °C, then the two branches are combined and flow out of the radiation chamber of the furnace and go to the fractionating tower (T102) for heat exchange with gas oil from the coke towers (T101/5, 6). After heat exchange, the heavy part of both residual oil and the gas oil join together, which is called circulating oil. The circulating oil is then divided into two branches (FRC8107, FRC8108) by pumps (102/1, 2, 3) and returned to enter the radiation chamber of the furnace (F101/3) to be heated to about 495 °C. Finally, the two branches join together and go to the coke towers (T101/5, 6) to remove coke. This process is called the coking of residues. The flows of the other two furnaces are the same as that of the furnace (F101/3), but the corresponding coke towers are different. The coke towers (T101/1, 2) are for the furnace (F101/1) and (T101/3, 4) for the furnace (F101/2). Each time, only one of each pair of coke towers works for its corresponding furnace, and when it is full, the other one replaces it. This replacement is called the switch of coke towers and the procedure recycles. The switch time of three pairs of coke towers is different. The heat exchange with gas oil from the coke towers poses a continuous disturbance on the outlet temperature because of the volume of the gas oil from the coke towers. During the switch of the coke towers, the outlet temperature of the furnace often drops and rises sharply because some of the oil in it will become gas oil, and part of the inlet gas oil flowing into it will be used for the heating of coke towers. What’s more, the random switch time of three pairs of coke towers adds to this serious problem.

Fig. 6.1Overall flow of coke unit

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.