Session: 10-03 Design and optimization

Paper Number: 82294

82294 - Development of Oil Free Centrifugal Blower As Enabling Technology for Solid Oxide Fuel Cell Anode Gas Recycling 

The transition of solid oxide fuel cells (SOFC) out of the R&D stage and into energy production markets has driven the need for development of customized supporting subsystems that are not just optimized for operation with SOFCs, but that are also capable of surviving the challenging operating conditions that they present. Such is the case of anode gas recycle blowers (ARCBs), which allow a fraction of the depleted fuel cell anode exhaust to be recirculated back to the inlet, thereby providing multiple plant efficiency and operation benefits. However, these blowers need to be designed specifically for handling the SOFC process gases, otherwise they can be susceptible to frequent maintenance, low reliability, and short life issues. These ARCBs can also represent a significant portion of the balance of plant (BOP) cost.

The authors discuss main aspects of the development and testing of a completely oil-free low cost centrifugal ARCB based on compliant foil bearing (CFB) technology, from concept to a high technology readiness level (TRL), for support of a 100 kW solid oxide fuel cell power plant. A broad overview of the design effort is provided along with a discussion of the role of CFBs and their highly specialized coatings in guaranteeing long life and maintenance-free operation in the high temperature, vapor-rich, and reactive anode exhaust gases. Key results obtained from over 1000 hours of laboratory tests are presented, which include temperature traces showing thermally stable CFB performance over extended periods of time and compressor performance maps showing robust choke/surge-free operation at operating condition ranges well exceeding those required by the fuel cell. Also included are field operation data, in the form of traces of blower performance parameters vs. time obtained during 3000 hours of operation in a fuel cell installation undergoing dynamic power load fluctuations.

Additionally, the authors discuss the advantages of this novel technology: how it compares to traditional systems, and the results of a basic techno-economic analysis, which shows the estimated fraction of the overall cost of the SOFC BOP the ARCB represents. Finally, strategies that are being adopted to reduce the overall cost of the technology at low-count production runs--when the benefits economies of scale cannot be leveraged--are discussed such as design for manufacturing (DFM) and the incorporation of additive manufacturing (AM). It is expected that the technology presented will be portable to applications beyond SOFCs, for example, in support of PEM fuel cells, electrolyzes, and hydrogen reformate compressors, as well as readily scalable to a broad range of power requirements.

Presenting Author: Rochelle Wooding Mohawk Innovative Technology, Inc.

Presenting Author Biography: Rochelle Wooding is a Mechanical Engineer at Mohawk Innovative Technology, Inc. (MiTi) in charge of the aerodynamic design of centrifugal turbines and compressors. She received her B.S. in mechanical engineering with a concentration in energy systems from the Rensselaer Polytechnic Institute in 2018. During her tenure at MiTi, Ms. Wooding has contributed to the design of multiple systems, including supercritical CO2 turbomachinery, microturbines for power generation, and to the design and implementation of a test facility for blowers and compressors for solid oxide fuel cells. She has also supported test campaigns for several power and energy projects. In her free time, Ms. Wooding is an avid mountain biker, rock climber, and overall outdoors enthusiast and adventurer.

Authors:

Rochelle Wooding Mohawk Innovative Technology, Inc.
Hannah Lea Mohawk Innovative Technology, Inc.
Jose Luis Cordova Mohawk Innovative Technology