Session: 37-03 Preliminary and structural design optimization

Paper Number: 101224

101224 - Optimization of Variable Geometry Turbine E-Turbo for a Heavy-Duty, On-Highway Fuel Cell Application 

An air compressor is a necessary component on fuel cell electric generators as fuel cells do not pull in air without an external aspiration. There are many fuel cell air compression options, each with their own benefits and drawbacks, such as roots-style screw compressors, radial e-compressors, e-turbos with wastegate, and e-turbos with a variable geometry turbine (VTG). Turbocharger turbine wheels for internal combustion engine applications are optimized to maximize exhaust gas enthalpy extraction while limiting centrifugal forces in the blades. In the presence of high temperature exhaust gas, 950-1050C for gasoline engines, material strength decreases, elasticity increases, and thus induced stresses must be reduced to prevent turbine failure or contact with the turbine housing. The proton exchange membrane fuel cell (PEMFC) exhaust gas temperature is significantly lower, in the range of 85-90C, which enables more degrees of freedom in the design and thereby a higher thermodynamic efficiency turbine. This work proposes a variable geometry turbine specifically for the fuel cell environment, and compares system performance through 1-D simulations at a lower-power road load and rated power point, to i) baseline e-compressor, ii) e-turbo with wastegate turbine, & iii) e-turbo with VTG designed for an IC engine environment. The VTG turbine optimized for fuel cell enthalpy harvesting has 13%-points higher efficiency at rated power compared to that of a typical ICE VTG, a relative increase of 23%. This study finds an optimized VTG e-turbo improves PEMFC efficiency at rated power by 3%, or 1.5%-points,compared to the e-compressor without a turbine.

Presenting Author: Alexander H. Taylor BMTS Technology

Presenting Author Biography: Dr. Alexander Taylor is engineering manager at BMTS Technology in Plymouth, Michigan USA, a leading exhaust gas turbocharger supplier headquartered in Stuttgart, Germany. He leads a team of application and test engineers and is responsible for R&D, turbocharger matching, validation and application design for US-based customers.

Dr. Taylor in an active participant in the SAE Powertrain Committee, which he joined in 2019, was Vice-Chair in 2020 and Chair in 2021. He was awarded the 2018 SAE John Johnson award for ‘Outstanding research in Diesel Engines’. Prior work experience is in heavy duty thermal systems (DENSO) and gas turbine engines (Rolls-Royce Aerospace).

Though currently based in Ann Arbor, Michigan, Alex calls rural Indiana home and attended Purdue University attaining his B.S., M.S., and Ph.D. in Mechanical Engineering. Graduate research at Purdue was in the areas of powertrain controls, diesel engine aftertreatment thermal management, and longitudinal vehicle control of class 8 trucks ("Platooning"). At BMTS, Alex has performed research in the areas of fuel cell boosting and electric turbocharging.

Authors:

Alexander H. Taylor BMTS Technology
Pavan Naik BMTS Technology GmbH
Simon Nibler BMTS Technology GmbH
Nisar Al-Hasan BMTS Technology