Design and Applications of Trend Monitoring System for Critical Process Variables

In Japan, the chain of serious accidents occurred recently at the major chemical companies is suggesting us that there is an urgent need to improve plant operations safety. Common problems lurking in the accidents are brought up. First, these accidents occurred at the abnormal situation for example after emergency shutdown. Second, in that time, the digital control system (DCS) may be at alarm flooding condition. Finally, the abnormal symptoms had always emerged; unfortunately operation people overlooked these signs.

In order to enhance efficiency of the plant operations monitoring, we have developed a trend monitoring system for the critical process variables (CPVs) during the steady and unsteady operations.

The main function of this system is future value prediction and prediction alarm for the CPVs. We will briefly explain outline of the functional design of this system with successful results in practice.

Keywords: Plant Operations Safety, Critical Process Variables, Trend Monitoring, Future value Prediction,

Predictive Alarm, AR (Auto Regressive) model