SBIR-STTR Award

Solid Oxide Fuel Cell (SOFC) systems are being developed as small (~ 5 kW) to medium (250 kW) distributed power plants. These systems, which offer very good efficiencies and tremendous potential for combined heat and power situations, could benefit from the implementation of an anode recirculation pump (ARP). Presently, no such pump exists in a reasonable package because the pump inlet temperature for this application is very high (~900 C). This project will develop a small regenerative pump, driven by a brushless DC motor, to solve this problem. The key characteristic of the ARP will be a thermal choke that is used to separate the hot process flow from the temperature sensitive drive components such as bearings, magnets, electronics, and motor windings. Phase I will design and test the thermal choke, evaluate and test best sealing approaches, develop integration of controller and motor, and develop a full solid model of final prototype pump. These tasks will involve early analysis followed by component testing.

Commercial Applications and Other Benefits as described by the awardee:
The anode recirculation should be applicable to either small or medium class SOFC systems, which could be competitive in residential and small industrial power, and in transportation (trucks and other large vehicles). In addition to SOFC systems, the pump technology could find use in other industries where very hot gases are being transported, for example semi-conductor manufacturing and industrial processing

Concerns about the high cost of energy, dwindling natural resources, and environmental pollution are pressuring the country to explore energy production technologies that offer greater efficiency and cleanliness. Solid Oxide Fuel Cell (SOFC) systems are one such technology. In order to operate SOFC systems at their best efficiency, the anode fuel mixture require recirculation. In turn, a hot anode recycle blower will be needed. However, the extreme temperature of the anode gas (850C) necessitates a very unusual blower. Additionally, the cost of this blower must be low enough to not appreciably increase the cost of the overall system. This project will develop a low-cost, high-temperature recycle blower for SOFC systems. In Phase I, a pumping concept was designed, built, and demonstrated at nearly 600C. Test station inadequacies prevented testing at full temperature, but the results indicated that the design should be adequate for the desired temperature. In Phase II, the pump’s thermal management technology will be demonstrated at full temperature. For cost reduction, the design will be modified to include the use of a high-volume low-cost motor and controller, and a reduced-size pump head. For performance improvement, the regenerative pump head will be adjusted to use improved aerodynamics. Finally, the cost-reduced version of the pump will be demonstrated for 5000 hours.

Commercial Applications and Other Benefits as described by the awardee:
Implementation of this recycle blower in Solid Oxide Fuel Cell systems should provide an approximately 10% improvement in overall efficiency