外文翻譯--催化裂化過程中典型控制的應(yīng)用（英文）

1、 Procedia Engineering 69 ( 2014 ) 1469 – 1474 Available online at www.sciencedirect.com1877-7058 © 2014 The Authors. Published by Elsevier Ltd. Open access under CC BY-NC-ND license. Selection and peer-review

2、 under responsibility of DAAAM International Vienna doi: 10.1016/j.proeng.2014.03.143 ScienceDirect24th DAAAM International Symposium on Intelligent Manufacturing and Automation, 2013 Application of Plantwide Control St

3、rategy to the Catalytic Cracking Process Cristina Popa*Petroleum –Gas University of Ploie?ti, 39 Bucure?ti Blvd., Ploie?ti, ROMANIA Abstract This paper presents an application of plantwide control strategy for a complex

4、 process, like catalytic cracking process. The plantwide control strategy assists the engineer in determining how to choose the best manipulated, controlled and measured variables in the plant, when is using advanced c

5、ontrol techniques such MPC. The result of applying plantwide control to catalytic cracking process is a hierarchical control structure, which is organized on three levels, with two advanced control techniques for the s

6、econd level. From economic point of view, the development and the implementation a hierarchical control structure for the catalytic cracking process is leading to increase plant efficiency. © 2014 The Authors. Pub

7、lished by Elsevier Ltd. Selection and peer-review under responsibility of DAAAM International Vienna. Keywords: plantwide control, hierarchical control, fluid catalytic cracking 1. Introduction The fluid catalytic crack

8、ing is an important process in refineries for transforming heavy hydrocarbons in to more valuable lighter products. This process contains three main components: riser, striper and regenerator, see fig 1. In the riser, h

9、ot catalyst is brought in contact with the vaporized feedstock and cracking reaction takes place. The striper, located at the reactor top, being formed of a cyclones system for the separation of the feedstock and the r

10、eactor products in the gaseous phase, from the catalyst particles. The regenerator, in which the coke deposited on the catalyst during the cracking reaction, is burnt off to regenerate the catalyst. The regenerated cata

11、lyst is circulated back to the riser while the cracked products are sent to the fractionators for recovery. * Corresponding author. E-mail address: ceftene@upg-ploiesti.ro © 2014 The Authors. Published by Elsevi

12、er Ltd. Open access under CC BY-NC-ND license. Selection and peer-review under responsibility of DAAAM International Vienna1471Cristina Popa / Procedia Engineering 69 ( 2014 ) 1469 – 1474 2. Plantwide control - o

13、verview The approach into a hierarchical manner of the control activities associated to a chemical plant is known in specialized literature as planwide control. Practically, this approach is a design method for control

14、system based on structural decisions and consists in four major steps, as follows [1]: A. Specify the hierarchical control system design objectives, implying: a1. the plant production and control objective; a2. identi

15、fy process constraints that must be satisfied, including safety, environmental, and quality restrictions. B. Top-down analysis which consists: b1. identify the process variables, control degrees of freedom, control st

16、ructure and options for decomposition; b2. establish, in conceptual form, the overall control structure; C. Develop a bottom – up design, which supposes: c1. develop a strategy for a regulator control; c2. examine the

17、 potential of applying advanced control strategies; c3. evaluate the economic benefits of real-time optimization; D. Validate the proposed control structure These step are based on the combined top-down, and bottom –up

18、approaches of [1] and [2] and the hierarchical organization. The plantwide control strategy has been studies by different chemical process complex like: HDA process [3], ethyl benzene process [4], VCM plant [5], Tennes

19、se Eastman [6], reactor separator recycle system [7], acetylene hydrogenation process [8]. All these studies have confirmed improved of the performances economic for each plant. 3. Application of plantwide control stra

20、tegy to the catalytic cracking process The hierarchical control structure obtained by author after application of the plantwide strategy is presented in figure 2. The control structure contains three levels: the conven

21、tional control level; the advanced control level and the optimal control level. Step A. The objectives of the control system designed specific to catalytic cracking process were presented in the introduction part of th

22、e paper. The constraints of the process are presented in table 1. Table 1. The constraint of the process Variables Significance Constraints type Constraints The limit Tr Riser output temperature technological m

23、ax r r T T ?570?C Treg Regenerator temperature technological max reg reg T T ?800?C 3 P ?Pressure drop between reactor and regenerator safety max P P 3 3 ? ? ?3 bar Hreg Catalyst level in reactor technological m

24、ax reg reg min reg H H H ? ?2 - 6 m Step B. The second step supposes the selection of the process variables and the manipulated variables assigned for each hierarchical level. ? the third level – the specific variable

25、is the yield gasoline (which is subjected to maximization) and manipulated variables identified are the riser outlet temperature - Tr i and regenerator temperature Tregi . These variables are the setpoint for the seco