Integrated Intelligent Control of Gas Mixing-and-Pressurization Process

This paper presents an integrated intelligent control method for a gas mixing-and-pressurization process with the objective of controlling the calorific value and pressure of the mixed gas. The control system contains two subsystems: a calorific-value-and-pressure-decoupling (CVPD) control subsystem and a pressurization control subsystem. The CVPD control subsystem takes the calorific value as the primary control target and keeps the pressure of prepressurized mixed gas within a given range. It employs fuzzy and expert control, fuzzy decoupling control, and the concept of relative gain matrix to keep the calorific value constant at a specific value, suppress the influence of pressure, and intelligently adjust the amounts that four butterfly valves are open. The pressurization control subsystem regulates the converters of the pressurization machine through feedforward and feedback expert controllers so as to make the pressure of the mixed gas track a given value. Runs on an actual system show that this control strategy is effective and keeps the fluctuations in calorific value and pressure at a low level. This reduces production costs and improves product quality.