I am new in gasification, so you will forgive me if this is nonsense
Since gensets are sensitive to tar, I was thinking like this: what if Tesla turbine is used instead of genset?
Woodgas will drive the blades and flame of the torch will pull the gas.
I am new in gasification, so you will forgive me if this is nonsense
This guy is driving me crazy. An automated boiler on chips would do the trick. But I dont allow myself to dream away. First some real woodgas.
Hmm, regardless of whether the wood is converted into tar gas in the gasifier, or into “pure” wood gas, in both cases we get the same or similar amount of energy from a certain amount of wood, so it’s worth making an effort, studying and following known good advice on the construction of a gasifier. Here on this forum there is a lot of knowledge and experience in this field, but no one can learn it for you, …
Do a trial run on some smaller carburetor and engine to get a feel for that type of skill, then move on to a larger system.
Veljko, tar is generaly only a problem for begginers. We all went down that route. You make something resembling a gasifier, that kinda makes some gas, and expect to run any size engine off of it. Once you do some reading, make a well made and well sized gasifier generaly tar never reapears.
In the late 1980’s into the early 1990’s in the US state of Connecticut there was in development a regional benefit bio-mass power station project.
Intended to be several hundred to a thousand of mega-watts. For the better-on-paper efficiency the designer-engineers specified gas-turbine generators.
All other aspects of the big project were developed. Scrub growths woody harvesting. Chipping. To a central point truck delivering.
The gasification progressed and developed after some problems to reliably make tars free fuel gases.
But failure, after failure on those turbine generators.
It was silica building up unevenly on the high speed turbine blades. Unbalancing. Disturbing predictable flows through.
$63,000,000 in public money investments were eventually written off as a better-failed idea loss. The gasification blamed as unable to deliver as clean of burning fuel gasses as natural gas suppliers.
That plant location later bought up by private investors for pennies. And they installed GE steam turbine electric generators.
Now after three ownerships changes scaled back to only 37.5 MW. Using constructions and landfills woody wastes.
Search up the “Connecticut Bio-Mass Power Project.”
Then I could direct you to a failed multimillions dollar projects in the state of Hawaii, the state of Alaska. And one Canadian Province
ALL failed due to some lofty goal of a better gasification system or engine power uses.
Then there was the CPC failures dipping into Stirling heat engines. The engine promoters insisting on 2000 Centigrade temperatures continuously from the woodgas at the Hot end.
So long as they used conventional for-gas IC piston engines they were O.K. A burst of Heat and Pressure centered in an expanding space. T&P pressure energy converted to rotary shaft energy-motion. The balance of unconverted T&P dissipated. Then cooler charge quenched. Repeat. Repeat. Repeat.
It is pretty low efficiency, since you won’t be using the heat from the torch, but how exactly is that torch going to work with no pressure from inside the gasifier?
Exactly this is preventing me to try anything with a Tesla turbine. The stirling is a project Phillips tried year after year and didnt succeed. Well, if they cant acomplish, I wont for sure. On another forum every some time someone is trying to start a stirling, high pressure will break seals and leak away, bad efficiency, dead end road.
But still, the numbers seem ok for the Tesla turbine, efficiency might be bether then an ICE. If so, why dont you see them in real life? Charlie Solis is a very clever guy to put the steam in vaccuum, another potential danger eliminated . No big boom with a leak. If this is true, there are a lot of advantages. Simple parts, and little parts promise a long life span.
Edit, someone is asking for parts Whispergen again. If you speak off the devil . Company is bankrupt. Way to complicated. 20 bar N2 and the cycle is worse then ICE. Hopeless unless you need an anker for your boat.
Tesla turbines are interesting but I think it is a dead end for off-grid / flex fuel style generation.
Tesla turbines are flexible on fuels, yes, but if using steam as the working fluid you (a) need a boiler and (b) face normal steam inefficiencies: low peak steam temps (vs combustion), boiler inefficiencies and “heat of vaporization” losses.
If you use direct combustion you need a compressor for the combustion air (and wood gas if wood gassing), which on that scale is quite an undertaking. PS if you can make that big efficient compressor you should use it in a Ericsson cycle engine (a Stirling variant).
A direct combustion tesla has and requires all the features of a proper jet turbine. The only advantage of a tesla turbine over a traditional jet turbine is that the expansion (energy harvesting) section doesn’t require precisely engineered blades that can withstand cantilevered pressure at high temps and ultra high RPMs. Tesla blades are also more tolerant of blade erosion so you might get away with aggressive water injection where a axial jet turbine would face catastrophic blade erosion in a hot second.
University investigators have not found better efficiency from tesla turbines, in fact the opposite. And Tesla turbines are used in industry already, just as trash pumps where entrained debris would ruin a regular pump in short order. It’s not like tesla turbines are a secret to professional engineers and designers. I had high hopes when I entered the rabbit hole and few as I exited.
Stirling doesn’t work at scale for reasons I’ve posted on before. You can’t buy a good one; if you could it would be $5k per HP, and you can’t build one because they are VERY sensitive to design and materials optimization. You’ll spend a thousand hours in the shop with nothing to show for it vs buying a predator 670 and welding up a gasifier in a week or two.
Thanks, nothing beats a ICE, and thanks for saving me the rabbit hole.
If the Tesla turbine was a pump, it seemingly would make a pretty decent, easy to build, anti-spark air pump to run an ejector pump or for a forge. Since it is basically tin can lids spaced with washers on a shaft.
Tesla turbines work much better at low speeds. And are more efficient then turbines at low speeds. but apparently they max at like 35% efficient according to some post I read, which I couldn’t verify the number. which is competitive with naturally aspirated ICE.
As pumps they are called ‘centrifugal’ pumps, and used across a variety of industries from oil to bio research types of applications.
Stirlings are used a -lot- for ultra low temperature freezers. They can get to -80C where as a standard compressor system would need a multiple stage compressor to get that low of a temperature. It is used for bio research and medical tissue samples. They make ones that are transportable so the doctor can send a sample to the lab.
Apparently aliexpress has a 5kw generator stirling for 1350 dollars whether it is any good or not, I do not know. If it is decent, there is a lot of potential to extract waste heat from a gasifier before or after combustion. But you have to check the working temps of the system similar to peltiers.
Sean - appreciate your points and am familiar with much of the same. Refrigeration ends up being easier than heat engine mode for Stirlings for reasons I’m sure you already know. I really wish it was more practical. Maybe the AliExpress vendor knows something we don’t?! Would be great…
If you are ready for a new rabbit hole check out Ericsson cycle engines. It costs you a fast pressure valve that Stirlings don’t need it but dodges some fundamental design conflicts that plague Stirlings.
A basic block diagram model still points you towards high pressure working gases (like 50-100 ATM+) but its more manageable. Lonny Johnson’s JTEC is a twist on the Ericsson cycle and very neat. I wouldn’t start there but do check out his JTEC when you “get” Ericsson. It’s like a fuel cell and Stirling engine had a baby.
highly doubtful, they tend to copy working designs and manufacture them errm cheaply.
The JTEC is interesting technology. Only 17% efficient. But what really makes it interesting is they are claiming it works for portable devices and wearables.
Which seemingly puts in into competition with nano-antenna’s. There is a better article then this somewhere…
That’s a nice, optimistic paper. They do acknowledge the difficulties in getting any power out of these antennas. There are two problems (at least). The voltage you get out of an antenna varies roughly as its size. At 1/25 the size of a human hair, the voltage is going to be really low. Much too low to turn on a diode rectifier, which would be the simple way to convert to DC. The frequency of infrared (really really really high, which is why nobody uses wires or antennas) makes it really hard to produce rectifiers that will work, even if you had reasonable voltages.
Not saying it can’t work, but I wouldn’t plan on it.
It looks like it is a ways off. These guys are claiming ~1% efficiency.
There you go, and back to ICE. All reciproking movements. Tesla turbine was promissing… very very simple design.
It occurred to me that the Tesla turbine is similar to the Stirling engine in a way. Both have efficiency and technical issues as engines that make practical use difficult. But both are more useful as “pumps.” The Stirling is an effective heat pump for cryogenic temperatures, and the Tesla turbine is very similar to Gaede’s molecular drag high vacuum pump.
Interesting to note that Gaede’s patent predates Tesla’s.
Tesla improved that vacuum pump design by incorporating multiple stages to it.
They probably all can be used in reverse as a turbine but may not state that explicitly in the early patents. Then it was improved again in 1975, but this one says it can be used in reverse as a turbine.
And here JeopK you key onto the core of the combustion-confusion make-power situation.
Those seeing the obvious energy released made in the flare-off on Ben Petersons personally made by-the-book-systems in this topic originators picture.
Those pixilated with whom-ever’s latest “Rocket Stove’s” power release maker.
Versus those who will appreciate and apply the converted impulse cyclic combustion power in an Internal Combustion piston-in-a-cylinder(s) engine.
The first group-think always insistent that a continuous combustion process just has to be more fuel use efficient. Not true. Not true at all.
A four-stroke internal combustion engine ONLY uses fuel for less than 1/4 of every 720 degrees of rotational time. Yet with fly-wheeling, or overlapping cylinder contributions, does supply continuous rotational able to be put to work power.
Once the exhaust gases are showing absolute minimal uncombusted HC’s (hydrocarbons) and absolute minimal CO (un-fully combusted) and a +/- 16% carbon dioxide you ain’t going to get better efficiency of combustion.
So then criticize, nit-pick, the IC piston engines conversion from the impulse T&P pressure pulses, to a smoothed rotary mechanical power.
And go ga-ga; yadda-yadda about different has-to-be better ways to do this.
Stupid. Narrow minded. Not focuses in works useable end results using a rather low density; as raw of fuel possible, directly.
Now. . . take that IC piston engine’s unconverted exhaust heat. Take that IC piston engines preserving metals cooling jackets removed heat; and put them to useful working. THEN is where you easy-do get a minimum of 70% to as high as 90% fuel-use cycle efficiencies. Everybody can find uses for hot water.
And you do not need a big centralized power plant suppling district heating also to achieve these efficiency percentages.
Use these IC piston engines local made heats to pre-dry down and condition the wood stocks just before they go into the wood use power maker. That greatly results in a far higher in-converter NET-power making capability. With far less contaminating by-products to fight.
But then I am a see-do, and use; practical man. With no interest in convincing higher-authorities; Farming for Grants. Getting myself named as Progress Forwards saint. Getting myself Paper published. Making a million dollars to be able to later walk away and live drinking Pina-colada’s.
Totally correct, enough subsidy companies in this world already. I had never heard of the Tesla Turbine unitil someone posted here something, and now for the second time. I didnt say anything the first time but got interested. Efficiency is the most important thing when converted heat into mechanical work. If it aint better then an ICE it is useless in my eyes. Better stick to what we have already. Greenturbine, Stirling, etc, for me useless. My Lister HRw2 will work, so would a CS (somewhere a CS iz waiting for me to pick up), but they jump up and down . The Tesla turbine will spin forever and ever, but if it doesnt meet the Lister it is useless to think about.
Look at Tones Jenbacher, if that happens to me it is end of story. Where do I find the time and skills to repair such an engine?