1. Core value of accident prevention
The interior of a coal mill is a typical flammable and explosive environment. When coal powder mixes with air and forms a combustible dust cloud, if the CO concentration accumulates to the explosion limit due to spontaneous combustion and encounters a tiny spark, it will trigger a violent explosion. Data shows that over 80% of coal mill failures are related to coal powder self-ignition, and the increase in CO concentration appears earlier than abnormal temperature indicators by more than 2 hours, becoming a "preliminary warning signal" for fire and explosion. The CO analyzer can prevent the accident chain in advance by real-time capturing ppm-level concentration changes: when the concentration reaches the warning threshold, an audible and visual alarm is triggered immediately; when the concentration exceeds the limit, the inertization system (injecting nitrogen), adjustment of wind temperature, or emergency shutdown will be automatically activated to prevent equipment damage and personnel poisoning and casualties from the source.
2. Compliance mandatory requirements
According to national standards such as "Technical Specifications for Explosion Prevention in Coal Powder Preparation Systems of Thermal Power Plants" (DL/T 5203-2023) and "Fire Protection Standards for Coal Chemical Engineering Design" (GB51428-2021), the coal mill system must be equipped with a fixed CO monitoring device and must meet hard indicators such as explosion prevention, accuracy, and linkage control. Among them, the GB3836 series explosion-proof standards clearly require that equipment have an explosion-proof level such as Ex dⅡCT6 or Ex iaⅡCT6, which can be used in explosive hazardous areas of the coal preparation system; at the same time, the detection data must be connected to the DCS control system to achieve full traceability, and equipment that does not meet the standards will be listed as a major accident hazard.