The Korea East-West Power Company (EWP), the owner of the Dangjin Coal Fired Power Complex (DCFPC) in South Korea has installed the early warning system to avoid the risk of spontaneous combustion in the coal conveyor system at the plant.
The thermal imaging cameras help ensure plant safety and continuity of power production by detecting any rise in temperature in the coal long before it reaches the point of combustion.
Huge quantities of coal stored in bunkers, silos, hoppers and open air stockpiles lead to greater risk of spontaneous combustion. When coal starts oxidising with the oxygen in the air, it causes a rise in temperature, which if left unchecked can go even above 400ºC, causing the coal to burst into flames.
The coal can additionally produce large amounts of toxic methane and carbon monoxide gases during the pre-combustion oxidisation process, further complicating the efforts of firefighters to extinguish the coal fires. It is therefore important to detect these conditions early so that an actual fire can be prevented.
Many coal storage plants are therefore enhanced with thermal imaging cameras as an early warning system based on thermal imaging technology that can detect the rise in temperature long before the coal ignites unlike smoke detectors, which require the production of smoke to function. Early measures can then be taken to halt the rise in temperature, preventing the actual combustion and the devastating coal fire that would follow.
Korea East-West Power Company (EWP) is one such company that has realised the potential of thermal imaging technology for fire prevention in coal storage plants. The Dangjin Coal Fired Power Complex (DCFPC) is one of five power plants operated by the company.
A conveyor belt system of several kilometres in length is used to transport the coal to the boilers, with the risk of spontaneous combustion very high during the journey. A coal fire at this stage would not only be dangerous for the plant’s personnel and destroy part of the conveyor system, but also impact power generation.
According to Kim Young Min, manager at DCFPC, the Environment Facility Team at the plant chose to build their early fire warning system around the FLIR A310 thermal imaging camera. Seven cameras have been installed at various points to provide a complete thermography-based early warning solution.
According to Kim Young Min, the FLIR A310 thermal imaging camera on detection of the slightest rise in temperature will not only automatically alert personnel, but also trigger the automatic sprinkler system to prevent or extinguish coal fires, enhancing plant safety and ensuring the continuity of the power production.
One FLIR A310 thermal imaging camera is installed at the storage end, checking the coal as it enters the conveyor system. Several additional FLIR A310 thermal imaging cameras check for any increase in temperature along the way.
All seven FLIR A310 thermal imaging cameras are connected using a standard Ethernet cable to a TCP/IP network, through which the thermal data from the FLIR cameras is shared with a PLC that will immediately stop the conveyor belt and activate the sprinkler system if any camera’s temperature alarm is triggered.
According to Kim Young Min, the FLIR A310 thermal imaging camera was chosen not just for the camera quality, but also because of the easy integration with DCFPC’s existing PLC. The camera also satisfies all their requirements such as remote control through the TCP/IP network, seamless integration with the PLC and live monitoring of thermal footage in the Control Room using analogue composite video.
Key features of FLIR A310 thermal imaging cameras:
- Uncooled microbolometer detector produces thermal images
- Image resolution of 320x240 pixels at thermal sensitivity of 50 mK (0.05ºC)
- Built-in analysis functions provide spot temperature measurement and area temperatures, and automatic alarm function
- TCP/IP connectivity allows seamless integration into the system
- Triggering of temperature alarm is relayed by the PLC relays to the rest of the network, alerting employees
- Software solution based on FLIR IR Monitor software and FLIR SDK allows temperature graph and temperature trend analysis