This Small Business Innovation Research (SBIR) Phase I project will pursue the development of a novel design architecture for recovering exhaust waste heat energy from an internal combustion engine by converting heat into electricity. As vehicles become increasingly electrified, recovering a fraction of such heat by generating significant electrical power would off-load the vehicle alternator and substantially increase fuel economy. The proposed innovation uniquely combines the latest advances in component technologies from fields in thermal management and energy conversion, resulting in a thermo-mechanical system that promises to be reliable, compact, and scalable while ?scavenging? significant power efficiently. The research objectives include the preliminary design of a full-scale system and the design, fabrication, testing, and evaluation of a fractional proof-of-concept prototype. Based upon results, the feasibility of the TEG system design will be ascertained, and its commercial viability evaluated more fully.
The broader impact/commercial potential of this project is to recover a significant portion of the massive amounts of energy that is not utilized in our society but rejected in the form of waste heat from energy/power systems. Exhaust heat rejected to the environment from internal combustion engines continues to be a significant untapped source of energy, representing over 40 percent of the available energy in these engines. Most markets which utilize IC engines involve mobile or portable power such as automotive vehicles and military portable generators, requiring increasingly higher performance, efficiency, and reliability within a more compact and lightweight design ? key metrics addressed by the proposed innovation. While reducing energy consumption in these applications, the innovation also reduces emissions since less fuel is consumed, helping companies meet stricter emission standards -- most notably the Corporate Average Fuel Economy (CAFÉ) standards which impose high financial penalties for non-compliance. Other adjacent markets include stationary power generation, solid-oxide fuel cells, and potentially aircraft propulsion systems. In addition to meeting market need, the proposed design approach contributes technically towards new or improved system design methodologies and catalyzing system-level innovation ? a particular need in the area of automotive exhaust waste heat recovery.
In this NSF SBIR Phase I effort, we at VECARIUS, Inc. demonstrated the feasibility of a novel thermoelectric generator (TEG) system architecture to recover heat from high temperature gas or air source and directly convert it into electricity. We achieved all major objectives posed in the Phase I proposal. First, we determined a TEG integration concept for passenger vehicle market and key TEG performance / design requirements by, in part, collaborating with a major vehicle OEM manufacturer. Secondly, to meet the requirements, we developed a preliminary design of the proposed TEG concept. Thirdly, to prove feasibility of key characteristics of the system design, we designed, modeled, fabricated, and tested a fractional proof-of-concept (POC) system prototype using commercial off-the-shelf (COTS) BiTe thermoelectric modules and demonstrated power generation of more than 45 watts. In addition to proving adequate performance, the POC prototype meets mobility constraints of size, weight, and durability and is cost-effective since all components are already commercialized or have been prototyped and near commercialization for high volume. Through this NSF SBIR Phase I, we developed a sound technology platform having vast versatility and scalability (20x) and proved key characteristics of the system through designing, modeling, fabricating, and testing a POC fractional system prototype – capable of achieving over 45 watts using commercial off-the-shelf BiTe thermoelectric modules. These Phase I results provide a sound foundation for a Phase II project, which may include developing a larger TEG system to utilize high-temperature skutterudite thermoelectric modules and further improving certain areas of the system, including the radiation barrier and thermal interfacing.
