Proton exchange membrane fuel cells for electrical power generation on-board commercial airplanes

Abstract

Deployed on a commercial airplane, proton exchange membrane fuel cells may offer emissions reductions, thermal efficiency gains, and enable locating the power near the point of use. This work seeks to understand whether on-board fuel cell systems are technically feasible, and, if so, if they offer a performance advantage for the airplane as a whole.Through hardware analysis and thermodynamic and electrical simulation, we found that while adding a fuel cell system using today's technology for the PEM fuel cell and hydrogen storage is technically feasible, it will not likely give the airplane a performance benefit. However, when we re-did the analysis using DOE-target technology for the PEM fuel cell and hydrogen storage, we found that the fuel cell system would provide a performance benefit to the airplane (i.e., it can save the airplane some fuel), depending on the way it is configured. 3 AcknowledgementsThe authors of this study had a great deal of enthusiastic support from both within and outside of Sandia National Laboratories.Dr. Joe Breit of The Boeing Company directly or indirectly provided most of the information about airplane electrical systems and issues in current airplane design that might be able to leverage the capabilities of a fuel cell. In the rare cases he could not answer our frequent questions, he referred us to others at Boeing who were just as happy to help: Andy Bayliss for issues concerning airplane performance, Trevor Laib for information on the existing environmental control systems, and Farhad Nozari and Casey Roberts for more electrical system details.Ryan Sookhoo of Hydrogenics was gracious in his support of our project, offering details on their PEM fuel cell technology to assist us in making reasonable estimates for the current state of the art as well as predictions of what may be possible for future aviation-designed fuel cell systems. His insight into the European world of aviation fuel cells was also useful to help put this study into perspective.Dr. Andy Lutz of Sandia (now at the University of Pacific) provided his extensive knowledge on the Simulink thermodynamic models that were used in this study.Of course, this project would not have taken place without the support of the Department of Energy's Fuel Cell Technologies Program, Pete Devlin and Nancy Garland in the Market Transportation group in particular. The encouragement and suggestions we received from them was invaluable. 4 SummaryFuel cells have become increasingly important as alternative sources of power, offering the potential for drastic reduction in emissions in particulate matter (PM), nitrogen oxides (NO x ), and CO 2 . In addition, they offer exceptionally quiet operation, highly efficient use of the fuel energy, and a high energy storage density compared to batteries. For a number of years, the manufacturers of commercial aircraft, most notably Boeing and Airbus, have realized that fuel cells may offer advantages for commercial aircraft operation. Apart from emissions reductions and thermal efficiency...

A Fuel Cell System Sizing Tool Based on Current Production Aircraft

“…Even though current PEM FC technology cannot be used to completely replace the APU on large civil airliners, partial substitution of existing electrical generation equipment for fuel cell technology should be considered on a case-by-case basis [14].…”

“…Several studies have previously considered the integration of fuel cell systems into aircraft [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Different aspects of the integration process have been considered.…”

“…Different aspects of the integration process have been considered. These included the theoretical integration of a FC system to partially cover the electrical load on the APU on a Boeing 787-8 [14]. In addition, working prototypes on a small remote piloted scale have been designed and flown [4][5][6][9][10][11].…”

“…A possible alternative would be to use SOFC technology as it is capable of being fuelled by light hydrocarbons which could potentially be stored in a similar manner to current jet fuel. The use of SOFCs in aircraft has been a topic of extensive research [4,[69][70] with key conclusions meriting the efficiency of SOFC technology and the potential to use the highquality waste heat.Even though current PEM FC technology cannot be used to completely replace the APU on large civil airliners, partial substitution of existing electrical generation equipment for fuel cell technology should be considered on a case-by-case basis [14].Page 8 of 1106/22/2017 …”

“…The significantly higher operating temperature of a SOFC (700-1,000°C) compared with 60-100°C for a PEM FC [3] allows it to reform light fossil fuels such as methane into hydrogen. However, if PEM fuel cells are used, then their relatively low operating temperature could potentially reduce the thermal signature of the electrical generation and/or propulsive system of the aircraft.Several studies have previously considered the integration of fuel cell systems into aircraft [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Different aspects of the integration process have been considered.…”