Harmful gas online monitoring system

System Overview:
Common harmful gases can be classified into irritant gases and suffocating gases based on their properties. Stimulating gases refer to gases that have a stimulating effect on the eyes and respiratory mucosa. They are toxic/flammable gases commonly encountered in the chemical industry, including chlorine, ammonia, nitrogen oxides, phosgene, hydrogen fluoride, sulfur dioxide, sulfur trioxide, and dimethyl sulfate; Asphyxiant gases refer to toxic gases that can cause hypoxia in the body, such as nitrogen, methane, ethane, ethylene, carbon monoxide, nitrobenzene vapor, hydrogen cyanide, hydrogen sulfide, etc.
The State Administration of Work Safety Order No. 40 requires that major hazard sources of enterprises should be equipped with uninterrupted collection and monitoring systems for temperature, pressure, liquid level, flow rate and other information, as well as combustible gas and toxic and harmful gas leakage detection and alarm devices, and have functions such as long-distance information transmission, accident warning, and information storage.
In response to the aforementioned requirements, Hangzhou Shanghang has launched the SH-CEMS2002 series harmful gas online monitoring system, which is specifically designed for harmful gases, based on years of experience in environmental monitoring. This system is an online monitoring system independently developed by the company, providing a good solution for continuous monitoring of harmful gases, ensuring the safety of industrial workers and hazardous devices, and preventing hazardous factors such as toxic/flammable gas leaks, excessive pressure, and abnormal temperature that may pose safety hazards to the enterprise.
Scheme composition:
In this scheme, the data collection, data processing, and system monitoring units are designed in layers, and the network topology principle is shown in Figure 1.



The top-level data monitoring layer is the data monitoring center, which consists of one or more industrial control computers, realizing real-time display, storage, printing and other functions of data, and sharing data through the network. The middle layer is the data processing layer, which is composed of multiple programmable controllers according to the system requirements. CLK (or PC-LINK) data communication is used according to the operating conditions. The bottom layer is the data collection layer, and the data collection terminal is directly attached to the data collection point. Through fieldbus, the entire system can form a distributed tree network data acquisition system, and the bus transmission distance connected to each node can reach 1200m.
The monitoring data mainly includes two categories: harmful gas concentration monitoring and related parameter monitoring (temperature, pressure, liquid level, flow rate, etc.). The monitoring scenario is shown in Figure 2.



System performance:
1) Key indicators can be automatically monitored and alarmed online;
2) Using waterproof aviation joints, easy installation and maintenance, good waterproof and dustproof performance;
3) Powerful software processing capabilities: Real time display, storage, over limit alarm, SMS alarm, data analysis, and print output of various monitoring data have been achieved;
4) Single bus real-time data transmission, simple wiring, low maintenance cost, and high system stability;
5) Fault self check, dual machine hot backup, and backup power supply ensure the stability and reliability of system operation;
6) Distributed network structure, some instrument failures do not affect system operation, and the system has good scalability.
(Editor in charge: admin)