(8) The DCS control system should distinguish between the first accident alarm

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Currently, many chemical companies are making extensive use of DCS systems to increase the automation of their production processes. The use of DCS systems makes it very convenient and inexpensive to set up alarms; however, this convenience and low cost also bring about corresponding problems – namely, arbitrary settings for alarms. In many companies, the current problem is no longer a lack of alarms, but rather an excess and inappropriate number of alarms. Such a large volume of inefficient alarms can obscure useful alerts, consuming excessive effort from operators and posing significant potential risks to production. This not only reduces production profits but can also lead to serious losses of life and property. Problems such as an unreasonable number of DCS alarm settings, improper priority configuration, incorrect parameter settings, and the inability to identify the cause of alarms are common issues in current DCS systems. Especially in the case of some accident alarms, due to the large number of such alarms, it is not possible to determine immediately which one is the first accident alarm. A great deal of effort is required to analyze and figure out which alarm represents the initial incident and which one is the root cause of the accident. If the first alarm can be identified right away, it becomes possible to determine the true cause of the accident promptly, thereby saving valuable time for subsequent emergency response actions. Therefore, it has become increasingly important to grade and categorize alarms so that operators can filter process alarms and improve the alarm management of DCS systems. The \"Design Specifications for Distributed Control System Engineering\" (HG/T20573-2012) stipulate that: 7.1.5 The alarm management and display functions of the operator station shall enable the alarm status to be displayed promptly on any screen. Alarm printing must be timely, and the first accident alarm must be distinguished. 7.3.7 The data processing capacity of the operator station shall meet the following requirements: 1. The system shall satisfy all data recording needs; the user can select the parameters for recording, the sampling interval, and the recording length, and the recorded data can be organized and retrieved at any time. 2. The permanent records on the hard drive should be able to be transferred to a storage device. 3. It should have a comprehensive alarm function, with a clear distinction between alarms for process variables and system failures. It should be possible to set arbitrary levels, zones, and groups for process variable alarms; it should also be able to automatically record and print alarm information, with the ability to distinguish between primary accident alarms. At present, the DCS control systems of many chemical enterprises are unable to effectively distinguish the first accident alarm. Why is it necessary to distinguish between the first accident alarm? 1. Distinguishing the first accident alarm allows for an effective and direct determination of the root cause of the accident. 2. Distinguishing the first accident alarm can optimize the operating cycle and service life of the equipment. 3. Distinguishing between the first accident alarm can improve the process operation procedures and enhance the level of inherent safety management in the process. How to distinguish the first accident alarm? Taking Zhejiang Zhongkong’s ECS-700 system as an example: (the configuration of control systems varies among different manufacturers), the interlock values for each measurement point are configured. The FIRST function module is used to record the interlock that triggers an alarm first; this module records the measurement point that first causes an alarm, thereby identifying the primary cause of the incident.