Session: 04-29 Emissions hydrogen/ammonia II

Paper Number: 126814

126814 - Design, Analysis, and Experimental Testing of Hydrogen Lean Direct Injection Nozzles at Elevated Pressure 

Many challenges exist for commissioning a hydrogen combustor into future gas turbine engines; especially regarding achieving emissions goals. Previously, Escudero et al. and Tran et al. conducted a study to adapt the liquid fuel Lean Direct Injection (LDI) concept from Jet-A to gaseous natural gas-hydrogen blends and pure hydrogen. [1], [2] Experimental data were collected at atmospheric conditions using a Box Behnken design of experiments. The results suggested that biasing the air split in favor of the inner air circuit and increasing the swirl strength of this inner air passage should further reduce NOx emission. As a complement to the design of experiment, computational fluid dynamic (CFD) simulations of select injectors from the initial set were conducted to interpret flow behavior driving the emissions results and are presented herein. The information from the experimental and computational analysis was used to create a new injector set with expanded parameters, which were tested at atmospheric conditions in the current work. The results illustrate that the direction regarding swirl and flow splits indicated by the first round of testing did lead to improvements in NOx emissions.  Analysis of variance carried out on representative injectors demonstrate that the low emissions injectors feature performance representative of fully premixed combustion systems whereas the higher emission injectors feature more diffusion flame like attributed indicating relatively poor mixing.  These attributes were affirmed by detailed CFD simulations. One injector configuration was selected for evaluation at high pressure conditions.  Initial results were obtained at pressures up to 6 atm and low (single digit) NOx emissions were observed.  The design direction indicated by the initial tests and CFD results in promising configurations for implementation into a Multi-point LDI array.

Presenting Author: Malcolm Overbaugh University of California

Presenting Author Biography: Graduate Student Researcher

Authors:

Malcolm Overbaugh University of California
Vincent Mc Donell UC Irvine
Phillip Buelow Collins Aerospace
Jason Ryon Collins Aerospace
Brandon Williams Collins Aerospace
Ottavio De Beni Collins Aerospace