Waste Heat Recovery
[Due to the increasing size of the archives, each topic page now contains only the prior 365 days of content. Access to older stories is now solely through the Monthly Archive pages or the site search function.]
Manchester team proposing graphene-based ballistic rectifier for waste heat recovery
June 03, 2016
Researchers at the University of Manchester (UK) have developed a graphene-based nano-rectifier (“ballistic rectifier”) that can convert waste heat to electricity. The nano-rectifier was built by a team led by Professor Aimin Song and Dr. Ernie Hill, in collaboration with a team at Shandong University (China).
The device exploits graphene’s phenomenally high electron mobility—a property which determines how fast an electron can travel in a material and how fast electronic devices can operate. The resulting device is the most sensitive room-temperature rectifier ever made, the researchers said. Conventional devices with similar conversion efficiencies require cryogenically low temperatures.
NEC, NEC TOKIN and Tohoku University develop spin-Seebeck thermoelectric device w/ 10x better conversion efficiency
April 25, 2016
NEC Corporation, NEC TOKIN Corporation and TOHOKU UNIVERSITY have jointly created a thermoelectric (TE) device using the spin Seebeck effect (SSE) with conversion efficiency 10 times higher than a test module that was produced based on a multi-layered SSE technology published by the Tohoku University group in 2015.
The spin-Seebeck effect is a thermoelectric effect discovered in 2008 by Prof. Eiji Saitoh and Associate Prof. Ken-ichi Uchida of Tohoku University (Keio University at that time). This is a phenomenon in which a temperature gradient applied in a magnetic material produces a spin current along the temperature gradient. The spin current is a flow of a magnetic property of an electron.
ORCnext project concludes waste heat recovery efficiency can be boosted by 20-25%
March 18, 2016
The four-year projet ORCNext, aimed at developing knowledge and design tools for next generation of Organic Rankine Cycles (ORCs), has concluded that waste heat recovery efficiency can be increased by 20 to 25% through appropriate cycle selection, efficient expanders, appropriate control and less oversizing of the heat exchangers.
The project, funded by the government agency IWT, ran from February 2012 to January 2016 and was a partnership between Ghent University, University of Antwerp, University of Liège and Atlas Copco.
Fraunhofer characterizes Alphabet Energy thermoelectric PowerCard; up to 5% fuel economy improvement in automotive
January 14, 2016
Alphabet Energy is commercializing low-cost, efficient thermoelectric materials for power generation leveraging technology initially developed at the Lawrence Berkeley National Laboratory. (Earlier post.)
The company has now announced characterization from the Fraunhofer Institute for Physical Measurement Techniques IPM of heat flow and thermal resistance (in air) of the Alphabet Energy PowerCard, the company’s core thermoelectric device for power generation. The PowerCard has shipped to customers in a variety of industries, including automotive; has been tested extensively; and is now entering high-volume production.
Manchester team greatly broadens thermal window of thermoelectric material using graphene; potential vehicle applications for waste heat recovery
July 22, 2015
Researchers at the University of Manchester (UK) have shown that the thermal operating window of the thermoelectric material lanthanum strontium titanium oxide (LSTO) can be expanded down to room temperature by addition of a small amount of graphene. Applications of LSTO-based thermoelectric materials are currently limited by their high operating temperatures of >700 °C.
Rather than working within the usual narrow “thermal window”, these bulk graphene/LSTO nanocomposites exhibit useful ZT values across a broad temperature range of several hundred degrees, the team reported in the journal ACS Applied Materials & Interfaces. This increase in operating performance can enable future applications such as thermoelectric generators in vehicles for waste heat recovery and other sectors, the researchers suggested.
Alphabet Energy introduces PowerModules for modular thermoelectric waste heat recovery; partnership with Borla for heavy-duty trucks
June 24, 2015
Alphabet Energy, founded in 2009 at Lawrence Berkeley National Laboratory, announced the availability of its thermoelectric generator PowerModule as a standalone product, available to meet the specific application needs of a range of industries, including transportation. The company also announced it will partner with Borla jointly to develop and to commercialize a next-generation-exhaust system incorporating PowerModules, with the goal of delivering significant fuel savings for commercial fleet truck fleets.
The Alphabet Energy PowerModule is a solid-state, liquid-cooled electrical generator that converts exhaust heat into electricity using Alphabet Energy’s proprietary PowerBlocks thermoelectric materials.
Free piston/ORC system for automotive waste heat recovery being tested at University of Brighton
June 18, 2015
A prototype automotive waste heat recovery system has been fired up on a recently commissioned test rig at the University of Brighton. The organic Rankine cycle test rig uses a novel linear free piston expander from Libertine (earlier post) to overcome the technical and economic barriers to using Rankine cycle technology for automotive waste heat recovery.
Initially configured to simulate heavy duty truck applications, the 20 kWe system can be scaled down to 3 kWe for light duty trucks and passenger cars. Libertine expects the results from rig tests to confirm the system’s potential to convert the high grade heat in the exhaust into electrical power, which can contribute to either powertrain or auxiliary loads.