Posted on 06/21/2006 3:55:36 PM PDT by aculeus
ATLANTA (June 21, 2006) — Georgia Tech researchers have created a new combustor (combustion chamber where fuel is burned to power an engine or gas turbine) designed to burn fuel in a wide range of devices ― with next to no emission of nitrogen oxide (NOx) and carbon monoxide (CO), two of the primary causes of air pollution. The device has a simpler design than existing state-of-the-art combustors and could be manufactured and maintained at a much lower cost, making it more affordable in everything from jet engines and power plants to home water heaters.
“We must burn fuel to power aircrafts and generate electricity for our homes. The combustion community is working very hard to find ways to burn the fuel completely and derive all of its energy while minimizing emissions,” said Dr. Ben Zinn, Regents’ professor, the David S. Lewis Jr. Chair in Georgia Tech’s Guggenheim School of Aerospace Engineering and a key collaborator on the project. “Our combustor has an unbelievably simple design, and it would be inexpensive to make and inexpensive to maintain.”
Attaining ultra low emissions has become a top priority for combustion researchers as federal and state restrictions on pollution continuously reduce the allowable levels of NOx and CO produced by engines, power plants and industrial processes.
Called the Stagnation Point Reverse Flow Combustor, the Georgia Tech device, originally developed for NASA, significantly reduces NOx and CO emissions in a variety of aircraft engines and gas turbines that burn gaseous or liquid fuels. It burns fuel with NOx emissions below 1 parts per million (ppm) and CO emissions lower than 10 ppm, significantly lower than emissions produced by other combustors.
The project’s initial goal was to develop a low emissions combustor for aircraft engines and power-generating gas turbines that must stably burn large amounts of fuel in a small volume over a wide range of power settings (or fuel flow rates). But the design can be adapted for use in a variety of applications, including something as large as a power generating gas turbine or as small as a water heater in a home.
“We wanted to have all the clean-burning advantages of a low temperature combustion process while burning a large amount of fuel in a small volume,” Zinn said.
The combustor burns fuel in low temperature reactions that occur over a large portion of the combustor. By eliminating all high temperature pockets through better control of the flow of the reactants and combustion products within the combustor, the device produces far lower levels of NOx and CO and avoids acoustic instabilities that are problematic in current low emissions combustors.
To reduce emissions in existing combustors, fuel is premixed with a large amount of swirling air flow prior to injection into the combustor. This requires complex and expensive designs, and the combustion process often excites instabilities that damage the system.
But Georgia Tech’s design eliminates the complexity associated with premixing the fuel and air by injecting the fuel and air separately into the combustor while its shape forces them to mix with one another and with combustion products before ignition occurs.
The project was funded by the NASA University Research Engineering Technology Institute (URETI) Center on Aeropropulsion and Power and Georgia Tech. The primary investigators on the project were Professors Ben T. Zinn, Yedidia Neumeier, Jerry Seitzman and Jeff Jagoda from the School of Aerospace Engineering, and Visiting Research Engineers Yoav Weksler and Ben Ami Hashmonay.
A comparison of Georgia Tech’s combustor with a traditional combustor: (Left) A traditional combustor mixes fuel and air before they are injected into the combustion chamber. (Right) Tech’s combustor injects the fuel and air separately into the combustor.
Sounds like the 150mpg carburetor we've heard about for the last sixty or seventy years. I suspect that fifty years from now we'll hear about the oil companies buying this one to keep it off the market.
You've been watching too much late night TV. On the other hand I see a lot of that at all times now.
Our mattresses are made out of space foam. Buy (your favorite baldness cure here) and stop losing your hair.
The ads on talk radio do get tedious, don't they?
This appears to use the same principles as the Scuderi "air-hybrid" engine, that has one cylinder compress the air, and then inject the compressed air into the combustion cylinder at the same time as fuel is injected.
However, the Scuderi engine also gets some benefit from the fact that the compressed air loses heat when it expands, which results in lower combustion temperatures, which results in lower NoX emissions as well.
I forgot: Get in on the ground level.
I am going to get rich helping this poor lady get millions of dollars out of Nigeria. Just a few fees to take care of first.....
As a Mechanical Engineer, I'm wondering about thermal efficiency with this setup. Sounds like a lot of heat is being siphoned off in some way, which WILL make any combustion process less efficient from an input energy/output power perspective.
Just wondering......
2 stroke ?
I had an uncle who had a friend who knew a guy who invented this device. Damn oil companies bought it from him!
From the patent:
http://www.freshpatents.com/Stagnation-point-reverse-flow-combustor-for-a-combustion-system-dt20060209ptan20060029894.php?type=description
" ...When the liquid fuel is burned in a non premixed mode, the fuel is injected separately into the combustor through an orifice aligned with the axis of the combustion chamber and the combustion oxidant is injected in through an annular orifice surrounding the fuel orifice in the manner similar to that used to burn gaseous fuel in a non premixed mode, as described above. As in the non premixed gaseous fuel combustion case, the oxidant stream is confined within two shear layer at its inside and outside boundaries. In the inside shear layer, the oxidant mixes with the injected liquid fuel stream. In the process, liquid fuel is entrained into the shear layer where it is heated by the air stream. This heating evaporates the liquid fuel and generates fuel vapor that mixes with the oxidant to form a combustible mixture. In the outer shear layer, the oxidant mixes with the counter flowing stream of hot combustion products and reacting gas pockets. The resulting fuel-oxidant mixture that is formed in the inner shear layer is ignited and burned in essentially premixed mode of combustion when it comes into contact with the mixture of oxidant-hot combustion products-reacting gas pockets mixture that formed in the outer shear layer."
The exhaust is remixed with the combustion air. Sounds cool.
This is the second major research breakthrough announced by Georgia Tech this week. On Monday, Georgia Tech and IBM announced the new fastest silicon microchip, which operates best at absolute zero temperature. The Ramblin Wreck is on a roll...
...working as little as 9 minnutes a week, from your home. There's no selling. No inventory to keep. You just sit back and let the money roll in!
Years ago, a friend of mine took the "blow by" on his '61 Falcon and routed it back into the the air intake by using an old bike inner-tube. His blue cloud disappeared for about a week, and then the whole thing just croaked from carbon build-up.
Thanks for the memory.
I was wondering how they would market those old EGR valves...
not knocking anything here but - the device is meant to run cool to avoid high temperatures and NOX emissions, it burns fully by having good mixing.
Oh by the way, virtually every new car and truck is already circulating post - combustion gases to keep down peak reaction temperatures.
Before you go too crazy with the rolling eyes and hooting, remember that this is Georgia Tech, not Ronco(tm).
Remember also before ramping up any dismissive "astronaut with a motorcycle hurr hurr" jokes, that NASA is also tasked with improving civil aviation design, powerplant design, and investigating improvements in airframe and avionics - not just sending gold plated records past Jupiter.
This is significant, as they are asserting in plain language that they're getting most of the fuel burned, therefore more energy out of the same amount of fuel. I'm interested.
If the gas temp at the exit of the burner is the same as at the exit of a conventional burner, overall efficiency of the engine shouldn't change since all the work is extracted from the gas flow downstream of there.
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