The Application of Neural Network Soft Sensor Technology to an Advanced Control System of Distillation Operation

For successful monitoring and controlling chemical process, an accurate on-line measurement of important quality variables is essential. However, these variables usually are difficult to measure on-line due to the limitations such as the time delay, high cost and reliability, so they cannot be directly close-loop controlled. In view of the problem above existing in an industry distillation column, a new design methodology is proposed in this paper. At first, an adaptive soft sensor instrument based on neural network technology was constructed as an alternative for the physical sensors. Then, the soft-instrument is correctly applied to an advanced control system and run successfully on DCS equipments. The data measured on-line show the control system has realized well the quality close-loop control.