The Building And Application Of Real-time Online Adaptive Dynamic Simulation Platform

The dynamic change in chemical process is inevitable and regular. Dynamic simulation can solve the problems in design, training, and production operation, which steady simulation based on material and energy balance can't deal with. As chemical process becomes more and more large, complicated, and various in demand, the simulation requirements both in real-time performance and model accuracy are getting much higher day by day.Traditional dynamic simulations are mostly off-line, and its model parameters can't be modified adapting to the operation condition change. So there is a certain limitation in real-time performance and model accuracy. In order to better meet the requirements mentioned above, the article proposed the building and application of real-time online adaptive dynamic simulation platform.To build real-time online adaptive dynamic simulation platform, several problems should be solved as follows:1. The acquisition and transmission of real-time data from DCS. The article adopted OPC technique to gather and transmit real-time data from on-site DCS system, so it provided the foundation for realizing online dynamic simulation. OPC technique can absolutely meet the requirement for real-time data by upper application programs, for its advantages of large data transmission quantity, quick velocity, high stability, and so on.2. The establishment of strict chemical mechanism model. Through the analysis of physical-chemical essence and mechanism of the process, we can use fundamental theories of chemical engineering to establish a set of mathematical equations and boundary conditions to depict the process characters. In the lumped parameter model, time variable is chosen as independent variable, to solve ordinary differential equation(s) in maths.3. Adaptive correction of model parameter. In on-site conditions, some performance parameters of the device will change along with the operation time, such as heat-transfer coefficient of exchanger, tower tray efficiency, catalyst activity coefficient, coking coefficient, and so on. In order to ensure the consistency between simulation results and locale condition change, model parameters that can characterize that change should be adaptively corrected until meeting the simulation accuracy requirement. The established real-time online adaptive dynamic simulation platform basing on above techniques can real-timely and accurately reflect the dynamic character change of chemical process, and can be used in chemical process monitoring, fault diagnose, online operation optimization, and so on. The article chose gas-to-ethylbenzene reactor as application example and achieved good results.