Additively Manufactured High Temperature Centrifugal Impellers for Low Cost SOFC Recycle Blower

The overall objective of the proposed effort is to incorporate additive manufacturing methods into the development of high and ultra-high temperature anode recycle blowers (ARCBs) for solid oxide fuel cell (SOFC) applications. It is expected that a successful execution of the project will leverage MITI’s ongoing efforts in this field, and contribute to reducing ARCB unit installation cost from MITI’s original stated goal of $110.00 per SOFC-generated kW of electricity (kWe) to a revised $90.27/kWe, with the consequent reduction in the component BOP cost for SOFC systems. The focus of the Phase I effort will be on the substitution of ARCB impellers manufactured by traditional methods with 3D printed ones. By nature of their extremely high rotation speeds (typically ranging from 50,000 to 100,000 rpm) and uncooled operation in high temperature environments (up to 750OC), these are the components subject to the most challenging mechanical and thermal operating conditions in the system. Therefore, it is considered that demonstration of successful use of additive manufacturing methods in their fabrication would pave the way for their use not only in fabrication of other ARCBs parts like shafts and housings, but also in 3D- printing other SOFC BOP components and as well as turbomachinery for other applications. Given that mechanical property data for materials used in additive manufacturing is generally sparse, and practically non-existent at the high temperatures required by the operation of ultra-high temperature ARCB impellers, MITI’s proposed project is a comprehensive effort to 1) identify how 3D printing of impellers—and ultimately other blower and compressor components—may result in cost reduction and performance improvements, 2 ) characterize the mechanical properties of 3D printed candidate materials at ARCB-relevant temperatures and operating conditions, and 3) design and manufacture 3D printed impellers with the improvements just identified and the newly characterized materials, and 4) subject the 3D-printed impellers to comprehensive metrology, component-level dynamic testing, and destructive testing for micro-structural characterization. MITI’s proposed strategy for the initial Phase I and Phase II effort distribution is as follows: Phase I of the project will be dedicated to material selection and characterization, fabrication of impellers by additive manufacturing, and laboratory-based analysis and component-level testing of impellers. For Phase II, MITI will leverage its demonstrated and delivered ARCB designs, along with existing testing facilities, and will install the 3D-printed impellers into ARCBs to perform full-speed and high temperature system performance and accelerated life testing in actual SOFC realistic operating conditions.