Abstract
This work supports the development of a low NOx emission 65 kW natural gas turbine capable of operating on 100% hydrogen. This gas turbine has been demonstrated to operate from cold start to full load on up to 30% hydrogen mixed into natural gas with single digit ppm NOx emissions. To reach operation on 100% hydrogen, injectors specifically designed to 1) avoid challenges with flashback and 2) be field retrofittable were developed and tested. Successful operation of the engine from cold start to full load on 100% hydrogen was demonstrated. To support the development, a chemical reactor network (CRN) is used in conjunction with experimental injector mixing characterization. A strategy to account for variation in mixing performance was developed and utilized with the CRN to connect NOx emissions to the injector mixing performance. Measured fuel concentration profiles and the CRN model was used to infer the effects of mixing on NOx emission. The results illustrate how NOx emissions are directly influenced by local fuel rich regions found at the injector outlet. The CRN model can thus be used to screen injector designs and infer NOx performance and will be used to guide the development of injectors for hydrogen that can attain desired fuel distributions, concentrations, and velocities. The results affirm the direction needed to attain improved mixing and to operate at overall leaner conditions made possible by the stabilizing features inherent to hydrogen.
