The Research On Expert System Of Cutting Off Tower In PSA

With the rapid development of chemical industry and the increasing requirement of high-purity hydrogen,the level of automatic control of hydrogen purification production was needed to improve.An expert system of cutting off tower in hydrogen purification production was developed based on the fully study of the structure and principle of expert systems.The process of hydrogen purification was studied,and the step of hydrogen purification production in normal six-tower and in error five-tower was obtained. The structure of expert system of cutting off tower in Hydrogen Purification Production was designed.The knowledge representation and reasoning method in expert system was designed by studying the fault recovery of hydrogen purification production.According to requirement of the time sequence and standard in cutting off fault tower,the knowledge database was divided into tower state knowledge database and tower rule knowledge database.In this paper the knowledge representation was described by combining the production rule and frame,while the reasoning strategy on purity tower state was accomplished by uncertainty reasoning method based on probabilistic reasoning,and reasoning mechanisms was designed by embeds multiple reasoning.The fault five-tower model and recovery six-tower model of hydrogen purification process was established.Using the expert system,the cutting-off tower of the hydrogen purification in different states was simulated.The simulation results showed that this expert system could analyze all sorts of tower states,make a right decision.The software of the expert system was accomplished by the tools of Visual Basic6.0 and Microsoft Office Access2003.The office access2003 was used to design the state database and rules database.The Visual Basic6.0 was used to realize the reasoning strategy and design the operator interface.The software's interface was friendly.The data communication between expert system and DeltaV system was realized by OPC technology.Through the off-line test,the expert system's test result met the expectation and attached the requirement of design.