Publications

Abstract not provided.

This report describes an FY13 effort to develop the latest version of the Sandia Cooler, a breakthrough technology for air-cooled heat exchangers that was developed at Sandia National Laboratories. The project was focused on fabrication, assembly and demonstration of ten prototype systems for the cooling of high power density electronics, specifically high performance desktop computers (CPUs). In addition, computational simulation and experimentation was carried out to fully understand the performance characteristics of each of the key design aspects. This work culminated in a parameter and scaling study that now provides a design framework, including a number of design and analysis tools, for Sandia Cooler development for applications beyond CPU cooling.

Abstract not provided.

Abstract not provided.

Deployed on a commercial airplane, proton exchange membrane (PEM) 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 could offer a performance advantage for the airplane when using today's off-the-shelf technology. We also examine the effects of the fuel cell system on airplane performance with (1) different electrical loads, (2) different locations on the airplane, and (3) expected advances in fuel cell and hydrogen storage technologies.Through hardware analysis and thermodynamic simulation, we found that an additional fuel cell system on a commercial airplane is technically feasible using current technology. Although applied to a Boeing 787-type airplane, the method presented is applicable to other airframes as well. Recovery and on-board use of the heat and water that is generated by the fuel cell is an important method to increase the benefit of such a system. The best performance is achieved when the fuel cell is coupled to a load that utilizes the full output of the fuel cell for the entire flight. The effects of location are small and location may be better determined by other considerations such as safety and modularity.Although the PEM fuel cell generates power more efficiently than the gas turbine generators currently used, when considering the effect of the fuel cell system on the airplane's overall performance we found that an overall performance penalty (i.e., the airplane will burn more jet fuel) would result if using current technology for the fuel cell and hydrogen storage. However, we found that with expected developments in PEM fuel cell and hydrogen storage technology, PEM fuel cell systems can provide an overall benefit to airplane performance. © 2012 Elsevier Ltd.

Abstract not provided.

Abstract not provided.

This presentation briefly describes the ongoing study of fuel cell systems on-board a commercial airplane. Sandia's current project is focused on Proton Exchange Membrane (PEM) fuel cells applied to specific on-board electrical power needs. They are trying to understand how having a fuel cell on an airplane would affect overall performance. The fuel required to accomplish a mission is used to quantify the performance. Our analysis shows the differences between the base airplane and the airplane with the fuel cell. There are many ways of designing a system, depending on what you do with the waste heat. A system that requires ram air cooling has a large mass penalty due to increased drag. The bottom-line impact can be expressed as additional fuel required to complete the mission. Early results suggest PEM fuel cells can be used on airplanes with manageable performance impact if heat is rejected properly. For PEMs on aircraft, we are continuing to perform: (1) thermodynamic analysis (investigate configurations); (2) integrated electrical design (with dynamic modeling of the micro grid); (3) hardware assessment (performance, weight, and volume); and (4) galley and peaker application.

Abstract not provided.