A scheme for using temperature sensing optical fibers in the distributed fiber optic temperature measurement system of coal mine goaf

Capteur de température à fibre optique, Intelligent monitoring system, Distributed fiber optic manufacturer in China

Fiber optic temperature measurement system for mining areas, distributed fiber optic temperature measurement system for coal mine goaf, and FJINNO providing distributed fiber optic temperature measurement devices for mining areas.

dts fiber temperature

China is the country with the largest coal production in the world and also one of the countries with the most severe spontaneous combustion of coal seams. This not only brings serious economic losses to coal mines, but also causes a large number of casualties among coal mine personnel. According to statistics, about 51.3% of state-owned key coal mines in China have the risk of spontaneous combustion, accounting for more than 90% of total mine fires. Due to coal seam spontaneous combustion, China loses about 200 million tons of coal resources annually; En même temps, coal spontaneous combustion is also one of the reasons for major malignant accidents caused by coal mine gas explosions. It can be seen that coal seam spontaneous combustion has become one of the main factors restricting the safe and efficient production and development of coal mines.

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Coal seam spontaneous combustion is a key focus of fire prevention and control work, with the vast majority of spontaneous combustion occurring in goaf areas. With the increase of coal mining depth and the significant improvement of mining mechanization, the mining speed is accelerating day by day. De plus,, the thickness of floating coal in the fully mechanized mining face is large, resulting in a continuous increase in the goaf area and an increase in the thickness of remaining coal in the goaf, leading to frequent coal spontaneous combustion accidents in the goaf. The production of fully mechanized mining faces is large and the equipment is sophisticated. Once spontaneous combustion occurs, it will inevitably cause huge economic losses. Therefore, preventing and controlling coal spontaneous combustion in goaf is the key to ensuring safe and efficient production of coal mines in China.

At present, the automatic monitoring and alarm system for coal mine spontaneous combustion fires in China adopts sensors with thermoelectric signals in principle, including thermistor sensors and thermocouple sensors. They are all processed using thermoelectric signals, so they are sensitive to the environment. The quality of the surrounding environment directly affects whether the system can operate normally. En même temps, sensors require power supply and transmit electrical signals, which have weak anti-interference ability and low reliability. The environment inside the goaf is harsh, so there are many safety hazards; And the signal transmission distance is short, which cannot achieve large-scale long-term online real-time monitoring.

With the development and progress of society and the rapid advancement of technology, the degree of mechanization in coal mines has significantly increased, the mining depth has continued to increase, and the mining speed has been accelerating. De plus,, the thickness of floating coal in the fully mechanized mining face is large, resulting in the continuous expansion of the goaf area and the continuous increase of caving height, leading to frequent coal spontaneous combustion accidents in the goaf. Once a coal spontaneous combustion disaster occurs, the concealment and uncertainty of the fire source will cause great difficulties in fire prevention and extinguishing work. However, the advanced equipment and large production of the fully mechanized mining face will inevitably cause huge economic losses, and even trigger disasters such as gas, coal dust explosions or smoke spread, leading to casualties. It can be seen that preventing coal spontaneous combustion in goaf is an important guarantee for ensuring safe and efficient production and development of coal mines in China.

Whether real-time monitoring can be carried out inside the goaf to accurately locate the location of temperature anomalies is the key to determining whether preventive measures can be taken in a timely manner to prevent fires from occurring. Therefore, real-time monitoring of goaf during the early stage of coal spontaneous combustion is an important part of fire prevention and extinguishing work. At present, the technologies for monitoring coal spontaneous combustion in China mainly include: indicator gas analysis method, tracer gas method, electric sensor temperature measurement method, and thermal infrared temperature measurement method. Their shortcomings are obvious. The commonality is that they cannot achieve continuous monitoring and can only monitor the temperature at specific points, which is likely to miss out on potential faults. The indicator gas analysis method requires all-weather collection and analysis of gas in goaf, which is labor-intensive and consumes manpower and material resources. There are very few missing substances that can meet the requirements of the missing gas method. Currently, this method is mainly based on laboratory research and is rarely used in real coal mines. The main sensors used in the electric sensor temperature measurement method include thermistor sensors and thermocouple sensors, both of which use the thermoelectric effect for temperature measurement. The transmitted signal is an electrical signal with a short transmission distance, so it is sensitive to the environment, has weak anti-interference ability, and low reliability. The quality of the surrounding environment directly affects the temperature measurement results; En même temps, sensors require power supply, and the environment inside the goaf is complex, posing many safety hazards. The thermal infrared temperature measurement method can only detect the temperature of objects on the surface perpendicular to the instrument. The complex environment of goaf has a great impact on the measurement results, and the fire warning system of infrared temperature sensors is expensive and difficult to promote.

 

dts fiber

Le temperature sensing optical fibers all use distributed armored optical cables. The distributed armored optical cables have stainless steel protective tubes and tensile steel wire mesh inside to protect the optical fibers from damage. The outer sheath is made of high-performance low smoke halogen-free flame retardant thermoplastic material, which has the advantages of anti impact, good tensile ability, flame and explosion resistance, corrosion resistance, high temperature and high heat resistance, easy construction layout, fast thermal penetration, and rapid temperature measurement response; The collection and transmission of temperature signals through mining temperature sensing optical fibers have a wide collection range, large coverage, long signal transmission distance, safety, stability, and reliability. Compared to a large number of point sensors, it can achieve online real-time measurement of temperature data and location information, disaster monitoring, and early warning prediction, greatly reducing the unit cost of obtaining information.

dts fiber optic

The use of distributed optical fibers to achieve online monitoring of the temperature field in the goaf of the coal mining face. Through subsequent processing of the monitored data, it is possible to achieve graded warning and determination of the ignition position of coal spontaneous combustion in the goaf. This has an important guiding role in mine fire prevention and extinguishing work, and can effectively ensure the safe and efficient production and development of the mine.

fiber optic dts

The method of distributed fiber optic temperature monitoring and early warning for coal mine goaf is simple, easy to implement, and can monitor the temperature of goaf in real-time online.