Design And Implementation Of DCS Control The Texaco Gasifier Lock Hopper System

In the21st century, DCS has entered the fourth generation of DCS, which is widelyused in chemical production， and it is affected by advanced communications,information management and technology, as well as large-scale process equipment.Yankuang Guohong500,000tons methanol project is constructed in2005. The projectuses advanced and reliable coal-slurry gasification, energy-efficient low-temperaturemethanol wash and maturity of the methanol synthesis of the world’s advancedtechnology, and1million tons of high-sulfur coal can be converted,500,000tons ofmethanol can be produced each year.In the device of the Texaco gasifier, accumulating and discharging dregs manuallycan lead to operation errors, even the parking of the gasifier, and affect the systemoutput; another aspect, the frequent slagging increases the operator’s labor intensity,brings operator fatigue, and threatens the safety of production.This thesis develops and designs the system of lock hopper serial control systemwhich can accumulate and discharge dregs in order to solve above problems. Thissystem mainly consists of accumulating dregs，discharging dregs and washing dregs oflock hopper. The development of this system shields all the disadvantages of manualcontrol，and provides a prerequisite for the security and stability of the long period ofthe gasifier operation. The main content of this thesis includes：(1) System requirementsand feasibility analysis: This section includes lock hopper system flowchart,requirements analysis, and feasibility studies;(2) Systems analysis: This section willlock hopper prone manual operation carried out analysis and research, and developed anew automatic operation of the program.(3) System design: it includes three mainfunctional modules：the order in which the lock hopper control systems, lock slagprocess in chronological order, and program design, covering the set slag lock hopper,lock hopper slagging off and lock hopper rinse t.(4) system implement: this partimplements the functional modules one by one based on the content of the design，draws the program flowchart, and then completes the implementation of automaticcontrol system which can actually run the lock hopper sequence. After designing the management system for testing，the four major functional blocks of the lock hopper’accumulating dregs, discharging dregs，washing dregs and security logic control arecompleted basically; one hand，it achieves automatic sequence control, defects ofshielding man-made control, on the other hand，it can control and manage the wholesystem on the basis of the safety logic at any time, and meet the high load, long cycle,stable and optimal operation needs； Finally, this thesis includes summary and outlookof the lock hopper serial control system.