Clean combustion for turbines

Siemens has begun research into clean combustion processes for future hydrogen-fired gas turbines. The gas, which can be obtained from renewable resources and has four times the energy content of natural gas, could be used in the turbines to generate electricity.

Siemens is working with the Russian National Research Nuclear University (MePhl) to identify combustion processes that produce the lowest possible amounts of nitrogen oxides.

The team is using simulations to identify burner concepts that generate the lowest emissions at the highest achievable combustion temperatures. The company notes that higher temperatures improve combustion efficiency.

The team is currently using simulations to identify low-emission burner concepts

Siemens is also reviewing methods for reducing the size of the hydrogen flame. A smaller, more stable flame produces fewer nitrogen oxides. Within this area of research, Siemens claims to have shown significantly reduced emissions with trials on a recently developed swirl burner.

The company has also been granted a patent for another method that uses an enhanced mixing of air and hydrogen to reduce the size of the flame. The advantage of this method is it keeps the flame as far away as possible from the combustion chamber and the turbine blades.

This is important because the temperature of hydrogen flames is very high, which can damage turbine blades.

While the goal is to combust hydrogen with pure oxygen instead of air, Siemens admits this is unlikely to happen any time soon. This is because production of pure oxygen is too costly and the combustion temperatures are too high for the turbine blades used in power plants.