Thermal imaging helps protect biofuel stockpiles

The storage of large quantities of organic material always carry the risk of spontaneous combustion and fire. With Europe’s commitment to bioenergy through initiatives, like the Renewable Transport Fuel Obligation, this is a growing problem. For energy producers in this sector, such an outbreak is not only a major health and safety issue but also one that involves loss of raw material and production downtime.

Thermal imaging has already proved its value in securing wide-ranging critical infrastructures against fire and intrusion and is now becoming established in the renewables sector too. A good example is a Swedish energy provider that has minimised its risk with the installation of FLIR A-Series thermal imaging cameras from the company’s Automation & Industrial Safety Division.

Söderengi produces both heat and electrical power by burning biofuels and recovered fuels. Its output provides district heating to a large area of Stockholm and sufficient energy to power 100,000 homes.  At its fuel terminal, just outside the city, forestry waste and wood chips are stored in massive piles.  In common with many other biofuel producers, it relied on visual monitoring and temperature probes to detect elevating temperatures and prevent fire.

One of the main problems associated with this method was the cost of the man hours it took to do the job thoroughly and reliably.  Also, a probe only provides spot temperature measurement, it does not enable the inspector to see the thermal profile of the entire heap of organic material. So, in 2015, the company decided to explore a more efficient detection system, one that monitored the stock piles continually and generated alarms before the situation reached a crisis point.  The goal was also to gain insight of how spontaneous fires develop, in order to be better prepared.

The tender was won by Termisk Systemteknik, a FLIR distributor that specialised in integrating fire prevention and detection systems for indoor and outdoor use.  One of its flagship products is TST Fire, an early fire detection system that continuously analyses the thermal camera stream in real time and generates an alarm when a pre-defined temperature threshold has been exceeded.  Through sophisticated video analytics, the system is also able to minimise false alarms, such as vehicles moving in the field of view.

To monitor the entire eight-hectare biofuel site, twelve fixed FLIR A615 automation cameras were specified and Termisk was able to use the existing lighting infrastructure for the installation. This model of camera was selected for its proven reliability and high resolution which, in turn, allowed the number of units needed to scan the whole area to be reduced.

The result was a very economical installation, not just because that fewer cameras were needed but also the FLIR cameras were able to perform multiple applications.

The TST Fire system with integrated FLIR cameras can also be used to detect people both from a security and safety perspective.  The benefit of using thermal imaging for this purpose is that it can monitor the scene during the day and night, without the need for illumination. The technology is also unaffected by the harshest weather conditions.

Fuel management at the site is a complex task as different types of biofuel are transported via rail or ship according to customer need.  FLIR thermal imaging can help in this regard too by monitoring the temperature of the fuel. For example, the thermal information can result in one fuel being given shipment priority over another to reduce fire risk.

Claes Nelson of Termisk concludes: “The information from the FLIR cameras is continuously combined with wind, temperature and precipitation data from the weather station.  The system allows the operators to see how long certain types of fuel can be stored and this is invaluable information as it allows them to work much more efficiently.”