Optimized Combustion: More Efficient Power

2008-Jun-04 | A new combustion measuring process is helping to improve the efficiency of coal-fired power plants. The core element of this system is a new laser-based measuring technology developed by Siemens and the American company Zolo Technologies. According to the research magazine Pictures of the Future, this technology makes it possible for the first time to analyze and automatically optimize the combustion process in a coal-fired power plant in real time. This could improve the efficiency up to three percent. What’s more, emissions of pollutants and the plant’s operating costs are reduced in the process.

The new measuring technology is being used in boilers up to 100 meters high and about ten meters in diameter. The boilers burn a ton of pulverized coal in just 15 seconds at temperatures of up to 1,400 degrees Celsius. Failure to achieve optimal distribution of air and coal in such units results in non-homogenous combustion. This, in turn, brings lower efficiency and increased formation of pollutants such as nitrogen oxides. Until now, the exact makeup of the air-coal mixture could not be determined because conventional measuring systems were only able to measure in flue gas, which is far removed from the combustion zone.

With the measuring technology from Siemens Fossil Power Generation and Zolo Technologies, the combustion process can now be thoroughly analyzed. To conduct this analysis, measuring heads are mounted at various heights on the internal boiler walls. The technology’s real-time measurements are achieved with a laser beam sent through the boiler. Various gases absorb the laser light. And depending on the ambient temperatures, either many or only few molecules are involved in this process. This makes it possible to determine the gas concentration and the temperature, and the combustion process can be optimized via automatically adjusted oxygen and coal feeds.

This new technology thus not only results in more environmentally friendly power generation but also offers huge savings potential when new power plants are constructed. The intelligent measuring procedure also could be used with gas turbines or in refineries.