Low Nox turbine

An experimental gas turbine simulator equipped with an ultralow-emissions combustion technology called LSI has been tested successfully using pure hydrogen as a fuel.

The LSI (low-swirl injector) technology, developed by Robert Cheng of the US Department of Energy’s Lawrence Berkeley National Laboratory, recently won a 2007 R&D 100 award from R&D magazine as one of the top 100 new technologies of the year.

The low swirl injector itself is a mechanically simple device with no moving parts that imparts a mild spin to the gaseous fuel and air mixture that causes the mixture to spread out. The flame is stabilised within the spreading flow just beyond the exit of the burner. Not only is the flame stable, but it also burns at a lower temperature than that of conventional burners.

The production of nitrogen oxides is highly temperature-dependent, and the lower temperature of the flame reduces emissions of nitrogen oxides to very low levels. Tests at Berkeley Lab and Solar Turbines showed that the burners with the LSI emit 2 parts per million of NOx (corrected to 15% oxygen), more than five times times less than conventional burners.