Engineering topics

Smith, Lance

Publications and source records attributed to Smith, Lance.

3 records

DOE OSTI2024

OPERATION OF FT4000® SINGLE NOZZLE COMBUSTOR WITH HIGH HYDROGEN

This paper reports initial results from an effort to develop a retrofittable fuel/air injector for the FT4000® aeroderivative gas turbine that enables use of hydrogen as a carbon-free fuel for efficient power generation. The FT4000 engine’s low-NOx combustor was developed by Pratt & Whitney and RTX Technology Research Center with core technology from the Pratt & Whitney PW4000 turbofan aircraft engine. The work reported here advances the technology readiness level of the FT4000 combustor for operation with hydrogen, starting with an experimental assessment of the current production hardware with increasing hydrogen content mixed with natural gas. High-pressure single-sector combustor rig tests have been completed, demonstrating the ability for the dual fuel nozzle to operate an FT4000 combustor on 100% hydrogen with low nitrogen oxide (NOx) missions. Metal temperature measurements and video images of the flame structure from zero to 100% hydrogen highlight opportunities to improve the fuel nozzle robustness for high hydrogen conditions. The current FT4000 production engine operates on either natural gas or No. 2 fuel oil with water injection to achieve high thermal efficiency and low emissions. This engine is fielded by Mitsubishi Power Aero and delivers 70 MW of power with a simple-cycle efficiency of over 41% when operating with wet compression. Results from this study have cleared the current production FT4000 engines with dual fuel nozzles to operate at baseload power on blends of hydrogen mixed with natural gas and water.

power generation↗

DOE OSTI2024

Extinction of Premixed Counterflow Ammonia-Air Flames

The effects of radiative heat loss and pressure on premixed counterflow ammonia-air flames have been investigated as a function of equivalence ratio. Non-adiabatic counterflow premixed flame simulations incorporating detailed chemistry, transport and radiative heat transfer in the optically thin limit have been employed to elucidate important underlying physics and extinction characteristics. Non-adiabatic counterflow premixed computations show that the combined effects of positive flame stretch and radiative heat loss for sub-unity Lewis number mixtures lead to the extension of the lean flammability limit for ammonia-air flames, revealing a C-shaped curve near the lean flammability limit that exhibits both radiative-induced and stretch-induced extinction states. The computations compare favorably with the experimentally determined extinction stretch rate values for the stretch-induced extinction states over a wide range of equivalence ratios at different pressures up to 6 atm.

10 SYNTHETIC FUELS↗

DOE OSTI2024

Effect of Pressure on Structure and Extinction of Counterflow Premixed Ammonia/Air Flames

With the growing interest in ammonia as a carbon-free fuel, numerous recent research efforts on fundamental combustion characteristics of ammonia have been reported. Despite this attention, there remain fundamental aspects that lack experimental investigation or validated chemical kinetic models. Specifically, the understanding of ammonia flame structure and the quantification of extinction limits at elevated pressures are incomplete. Furthermore, the chemistry of NOx in relation to ammonia flames has not been thoroughly examined, especially at pressure, and it is useful to explore the operating conditions that exhibit favorable flame stability with minimal NOx formation. In the current work, key characteristics of ammonia/air combustion, including strain-induced extinction limits and NO* chemiluminescence, are experimentally investigated over a wide range of equivalence ratios and pressures. This paper presents initial results in a study directed to improved comprehension of ammonia combustion chemistry, and acquisition of new datasets under elevated pressure and temperature conditions, to better refine rate expressions for important reactions in ammonia combustion.

08 HYDROGEN↗