System Architectures for Solid Oxide Fuel Cell-Based Auxiliary Power Units in Future Commercial Aircraft Applications

Abstract

Recent advancements in fuel cell technology through the auspices of the Department of Energy, the National Aeronautics and Space Administration, and industry partners have set the stage for the use of solid oxide fuel cell (SOFC) power generation systems in aircraft applications. Conventional gas turbine auxiliary power units (APUs) account for 20% of airport ground-based emissions. Alleviating airport ground emissions will continue to be a challenge with increased air travel unless new technology is introduced. Mission fuel burn and emissions can be significantly reduced through optimal systems integration of aircraft and SOFC subsystems. This study examines the potential total aircraft mission benefits of tightly integrating SOFC hybrids with aircraft subsystems using United Technologies Corporation Integrated Total Aircraft Power Systems proprietary methodologies. Several system concepts for optimal integration of the SOFC stack with aircraft subsystems are presented and analyzed in terms of mission fuel burn for technologies commensurate with 2015 entry into service. The performance of various hybrid SOFC-APU system architectures is compared against an advanced gas turbine-based APU system. In addition to the merits of different system architectures, optimal SOFC system parameter selection is discussed. The results of the study indicate that despite the lower power density of SOFC-based APU systems, significant aircraft fuel burn (5–7%) and emission reductions (up to 70%) are possible. The majority of the fuel burn savings are realized during aircraft ground operations rather than in-flight mission segments due to the greater efficiency difference between the SOFC system and the advanced APU technology.

Electrical Generation for More-Electric Aircraft Using Solid Oxide Fuel Cells

“…Braun et al (2009) Braun et al (2009) reported on the same study as Gummalla et al, three years later and in somewhat more detail. As before, the analysis was for a 162 passenger aircraft and a 1000 nm flight.…”

Retraction: High‐Performance Molybdenum Dioxide‐Based Anode for Dodecane‐Fueled Solid‐Oxide Fuel Cells (SOFCs)

“…[1][2][3] Among the various types of fuel cell, solid-oxide fuel cells (SOFCs) have been considered the most promising energy converter to meet the increasing demand for electrical power as many aspects of our society move towards a "more electric platform". [4][5] As one illustration of this trend, the Boeing Company has been pursuing the more electric airplane (MEA) concept, which aims at substituting hydraulically and pneumatically driven systems with electrical ones. [6] The current embodiment of the MEA concept is the Boeing 787 "Dreamliner".…”

Influence of Flow Path Configuration on the Performance of Hybrid Turbine - Solid Oxide Fuel Cell Systems for Aircraft Propulsion and Power

“…The systems investigated in both studies were carefully tailored to low power, very long endurance (several days) high altitude missions. [25] IPSE Pro 140 kW natural gas =60-70% Palsson et al [22] Aspen Plus 500 kW methane =86%, =60% Suther et al [23] Aspen Plus syngas Veyo et al [19] 300 kW, 1 MW natural gas 59% Zhao et al [24] MATLAB coal syngas =50-60% APUs: Braun et al [34] Proprietary 300 kW Jet-A SL: =53%, cruise: =70% Eelman et al [33] MATLAB 370 kW jet fuel >70% Freeh et al [29] NPSS 200 kW Jet-A =40%, =65% Freeh et al [31] NPSS 440 kW Jet-A =73% Rajashekara et al [8,32] 440 kW, >880 kg jet fuel SL: =61%, cruise: =74% Steffen et al [30] NPSS 440 kW, 1396 kg Jet-A =62% All-electric: Himansu et al [35] MATLAB 20 kW, 50 kW H 2 Aguiar et al [36] 140 kW H 2 =54-66%…”

“…Eelman et al [33] modeled 370 kW proton exchange membrane fuel cell (PEMFC) and SOFC hybrid concepts. Braun et al [34] modeled a 300 kW autothermal reforming GT-SOFC APU system using Jet-A fuel.…”