Light instead of electricity to measure temperature
Fujitsu uses light, instead of electricity, to measure temperature in thermal power stations. Fujitsu Limited and Tohoku Electric Power have co-developed an anomaly detection system for thermal power station facilities based on optical fiber multipoint temperature sensing technology. This method measures real-time temperature at over 10,000 locations with one optical fiber. The two companies conducted a field trial at Tohoku Electric's Akita thermal power station.
Fujitsu plans to develop this tech further to work not only with power stations but also other facilities, such as chemical plants.
The discrete temperature sensor used for the same purpose require a communication cable for each sensor, where as the temperature measurement through an optical fiber measures temperature along a several-kilometer long optic fiber at successive 10 centimeter intervals. Since this system uses light, instead of electricity, to measure temperature, it is not restricted by explosion prevention measures. Fujitsu says it is also possible to lower deployment costs compared with using discrete temperature sensors.
Fujitsu and Tohoku Electric Power used this optical fiber multipoint temperature sensing technology to continuously monitor temperature changes in the fuel pipes, steam pipes, and boiler flues at Tohoku Electric Power's Akita power station from June 2014 to March 2015. Based on Tohoku Electric Power's expertise in using temperature changes in power station-related facilities to detect facility anomalies, the two companies conducted a field trial involving an analysis of the measurement results and more refined real-time detection of facility anomalies, stated in the release.
Results of the Field Trial as disclosed by Fujitsu:
By analyzing the temperature measurement data for the steam pipes, the two companies were able to detect irregular condensation of steam and the occurrence of blockages. Furthermore, by comparing the timing of rises and falls in steam pipe and fuel pipe temperatures, they were successfully able to grasp whether the status of the various pipes was normal or not.
In addition, even in boiler flues, which expel high temperature exhaust gasses reaching 120degC, and which are subject to continuous vibrations, the companies were able to monitor temperatures for 60 consecutive days and carry out real-time temperature monitoring using this technology, even in such a high-temperature, high-vibration environment, showing it was also possible to detect anomalies in this type of facility.