1. Background

Electricity, cement, petrochemical, steel and other industries coal storage methods include open yards and indoor semi-closed, airtight, silos, etc., coal piles will continue to undergo oxidation reactions in the atmosphere, causing heat to accumulate and continue to rise, which can easily lead to spontaneous combustion. The oxidation rate of coal is directly proportional to the temperature generated during oxidation. When the oxidation rate of coal increases by 1°C at 30-100°C, the oxidation rate increases by 2.2 times. When the temperature of the coal pile exceeds 60℃, the oxidation of coal is accelerated, and the average temperature of the coal pile rises sharply. When the temperature of the coal pile reaches 100℃, the spontaneous ignition temperature can be reached within 1 to 2 days (the ignition point of coal is about 260-350 ℃), spontaneous combustion accidents occurred in coal yard in the early stage of spontaneous combustion, because low-temperature oxidation will produce carbon monoxide and the concentration of oxygen will also change, it is necessary to set up carbon monoxide and oxygen detection devices for real-time monitoring for early detection and timely measures. Oxygen concentration will decrease due to coal oxidation or ventilation system failure. In order to ensure the safety of the working environment, the oxygen concentration should be above 18% VOL; the content of combustible gas methane (CH4) in the air should be below 1.5%. By methane easier to diffuse than air, install a methane concentration detector on the upper part of the coal yard where the exhaust flow is concentrated for real-time monitoring. At the same time, when the dust concentration exceeds the standard, it will also bring potential accidents. It is also necessary to install the detector for dust concentration in the upper part of the coal yard to realize real-time monitoring. Existing detection methods are generally divided into manual inspections, temperature sensors on retaining walls, laying temperature sensing cables/optical cables around the retaining walls and in the bottom coal seam of coal yards, or installing smoke detectors and combustible gas detectors. The main problems are:

● Manual inspection is costly and low in efficiency, with many dead spots, long inspection cycles, and unavailability Effective data analysis and early warning;

● The contact temperature sensor has a large amount of installation work, it is difficult to locate the spontaneous ignition point, and there is a blind spot for monitoring , The damage rate is high, and the amount of maintenance is large;

● The number of temperature measurement points obtained by the temperature sensing cable or optical fiber cable is limited, and the monitoring is a coal pile The temperature at the bottom coal is high investment and cannot be maintained;

● The installation of smoke detectors requires a large amount of work, supervision after the event, no early warning treatment, difficult maintenance;

● Manual or automatic extraction of combustible gas for sampling, laboratory chromatographic analysis; heavy workload, It is difficult to judge the degree and area of spontaneous combustion.

2, plan

According to the regulations "Technical Regulations for Coal Transportation Design for Thermal Power Generation Part 3: Coal Transportation "Automation" Article 8.0.9 of DL/T5187.3-2012, "Silos and closed coal yards should be equipped with safety monitoring systems. The safety monitoring system should have functions such as temperature, combustible gas (including CH4 and CO), flue gas dust concentration detection and alarm. ” GS-SMS1000 coal yard safety monitoring and early warning system , dust concentration and various combustible gas safety index early warning intelligent safety monitoring system integrated with multiple online monitoring technologies. It not only integrates a number of existing products and technologies of our company, but also integrates multiple data acquisition subsystems such as detection channels, coal conveying belts, and coal retaining walls installed in the coal yard to improve system functions. According to customer needs , it can be divided into modules and sold independently. The system can be applied to closed coal storage yards in various industrial fields to realize the safe digital upgrade and transformation of coal yards.

3. Main functions

● Collect real-time data of various subsystems, including coal piles, open fire coal, coal retaining walls, combustible Gas, etc.;

● According to the infrared dual-vision thermal imaging camera installed in the coal storage yard, the coal conveying belt open fire coal monitoring. The temperature data output by the host and the coal retaining wall wireless temperature measurement host can perform temperature analysis functions, including temperature over-high alarm, temperature trend analysis, etc.;

● Analyze and determine the concentration detected by detectors such as CH4, CO, smoke, and dust to triggger alarm;

● A comprehensive display, real-time temperature and concentration value display, alarm status, alarm information display, history for inquiries, etc., except for the necessary display functional areas in the overview interface, whether to display other functional areas can be configured through software authority management;

● supports an external LED parameter screen, which can display the temperature of the coal pile, the temperature of the open flame of the belt, gas concentration and smoke alarm information.

4. Value

● 7×24 hours real-time monitoring of temperature field distribution of coal yard, hot spot tracking and location to ensure the safety of coal storage equipment;

● Satisfy the application of explosion-proof occasions, realize all-round, no dead angle, high-definition monitoring, to ensure clear viewing, accurate testing and long service;

● Using non-contact temperature measurement technology to overcome the shortcomings of traditional temperature measurement methods, the construction amount is small, maintenance-free, long service life;

● Reduce manual inspections, improve occupational health of employees;

● prevent fire origin, you can find hidden dangers in the early stage of the fire. Early warning processing to avoid accident escalation;

● According to the risk level, set up multi-level alarms, support alarm linkage with fire-fighting facilities, and reduce accident losses;

● adopts modular design and integrates mainstream products at home and abroad; it can be flexibly configured according to different scenarios , strong scalability;

● Using B/S architecture and configuration diagrams for multi-dimensional display and warning, no need for various subsystems Separate display, reduce control room display configuration;

5. Application case