Low Temperature Combustion
[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.]
Sandia CRF team provides experimental confirmation of oxidation scheme of lower emissions diesel alternative DME; new intermediates
October 17, 2015
An international team of researchers led by a group from the Combustion Research Facility (CRF) at Sandia National Laboratories recently provided experimental confirmation of the generally accepted low-temperature oxidation scheme of dimethyl ether (DME)—a lower soot and emissions alternative to diesel—at low temperatures (~540 K, 267˚C). Their paper was published in the ACS Journal of Physical Chemistry A.
Especially significant, they said, was detecting and identifying keto-hydroperoxide (hydroperoxymethylformate, HPMF, HOOCH2OCHO)—a previously undiscovered partially oxidized intermediate—thereby providing critical information needed to improve models.
New Argonne engine simulation project investigating effects of uncertainties on engine function; targeting gasoline compression ignition
August 25, 2015
Researchers at the US Department of Energy’s Argonne National Laboratory are launching a new simulation project from the Virtual Engine Research Institute and Fuels Initiative (VERIFI) (earlier post) to investigate how multiple variables—uncertainties—interact simultaneously to impact the functioning of an engine.
A primary focus of the research will be enabling a new generation of gasoline compression engines that operate on the basis of low-temperature combustion. A gasoline compression engine combines many of the benefits of diesel and gasoline engines by using compression to ignite the fuel in the same manner used by diesels. Vehicle manufacturers have shown interest in pursuing low-temperature combustion as an innovative route to more efficient engines.
DOE to award $55.8M for advanced vehicle technologies; $35M for fuel cell and hydrogen
January 22, 2015
US Energy Secretary Ernest Moniz announced a new Vehicle Technologie program-wide funding opportunity (DE-FOA-0001201) for $55.8 million. DOE also announced up to $35 million to advance fuel cell and hydrogen technologies, including enabling the early adoption of fuel cell applications, such as light duty fuel cell electric vehicles. This new funding opportunity announcement will be available in early February.
The Vehicle Technologies funding is targeted at a wide range of research, development, and demonstration projects that aim to reduce the price and improve the efficiency of plug-in electric, alternative fuel, and conventional vehicles. Topics addressed include: advanced batteries (including manufacturing processes) and electric drive R&D; Lightweight materials; Advanced combustion engine and enabling technologies R&D; and Fuels technologies (dedicated or dual-fuel natural gas engine technologies).
ORNL study finds multi-mode RCCI can offer 15%+ fuel economy improvements across multiple light-duty driving cycles
January 05, 2015
|Drive cycle fuel economy for PFI, CDC, and multi-mode RCCI operation. Credit: Curran et al. Click to enlarge.|
A team at Oak Ridge National Laboratory (ORNL) has added to the growing body of work exploring the applications and benefits of reactivity-controlled compression ignition (RCCI) by simulating the fuel economy and emissions for a multi-mode RCCI–enabled vehicle operating over a variety of US drive cycles using experimental engine maps for multi-mode RCCI; conventional diesel combustion; and a 2009 port-fuel injected gasoline engine. Their paper is published in the International Journal of Engine Research.
Among their findings were that multi-mode RCCI has the potential to offer greater than 15% fuel economy improvement over a 2009 gasoline PFI baseline over many light-duty driving cycles, despite the lack of complete drive cycle coverage for RCCI mode. Fuel usage over the drive cycles showed that nearly equal amounts of gasoline and diesel fuel would most likely need to be carried on board for RCCI multi-mode operation, which requires two fuels. During RCCI-only operation, fuel usage was found to be between 57 and 69% gasoline.
Tsinghua team devises in-cycle control method for diesel LTC using detection of Start of Combustion
November 25, 2014
Low temperature combustion (LTC) refers to a broad range of in-cylinder combustion strategies for the reduction of NOx emissions from diesel combustion; NOx is formed primarily by a thermal mechanism, which production rates increasing exponentially with temperature. LTC strategies reduce combustion temperatures by the dilution of the in-cylinder combustible mixtures, either with excess charge gas to create more fuel-lean mixtures, or with moderate to high levels of EGR.
However, challenges remain in diesel low temperature combustion implementation due to combustion inconsistency or instability. To address this, a team from Tsinghua University has devised an in-cycle combustion feedback control method based on the detection of the Start of Combustion (SOC) in diesel LTC. A paper describing their method is published in the journal Applied Energy.