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Enginion Steam Engine Oil Free Cylinders

Posted by peter heid 
Enginion Steam Engine Oil Free Cylinders
December 18, 2009 04:08PM
A R&D subsidiary of the Volkswagen group called Enginion AG was developing a system called ZEE (Zero Emissions Engine). The third prototype they produced was a three-cylinder unit meant to fit in a Škoda Fabia automobile. The EZEE03 was a single-acting engine of 1000 cc displacement, producing up to 220 hp. Exhaust emissions were said to be far below the SULEV standard. It had an "oilless" engine with ceramic cylinder linings using steam instead of oil as a lubricant. However, Enginion found that the market was not ready for steam cars.

<www.autofieldguide.com/articles/070102.html>

Peter Heid
Re: Enginion Steam Engine Oil Free Cylinders
December 18, 2009 06:40PM
What ceramic and what were the piston rings?
The attachment does not open up.

Jim
Re: Enginion Steam Engine Oil Free Cylinders
December 18, 2009 07:04PM
THIS IS THE AUTOFIELDGUIDE LINK - [www.autofieldguide.com] THE LINK TO THE COMPANY THAT BOUGHT ENGINION/STEAM CELL [www.amovis.de] MY STEAMLINKS WEBSITE [steam.netfirms.com] BEST REGARDS, EARL
Re: Enginion Steam Engine Oil Free Cylinders
December 19, 2009 02:58AM
Enginion spent about eleven million bucks of investor capital to get this far. The ceramic burner looked interesting as some type of hot head engine/generator combo. The rings were carbon, probably with some antimony added same as compressor rings.

I looked at the "patent" that they got for the ceramic cylinder coating and I believe they actually got away with patenting the periodic table of the elements. I guess the patent office bought the idea that because this was a steam engine so no body would have ever thought of finding a coating for the cylinders. IMO the patent is ridiculous.

At any rate, if one is to try carbon rings use an antimony filled variety. The molecular interaction of the antimony/carbon combination with any moisture might provide a sliding hydrodynamic surface but would need to be tested out.

Best, ------ Bill G.
Re: Enginion Steam Engine Oil Free Cylinders
December 19, 2009 05:39AM
The API 618 is regarded as the ‘bible’ by most compressor contractors and users. In the latest edition of API 618 dated June
1995, an important ideal for the compressor designer is laid down in section 2.1.1.

“ The equipment (including auxiliaries) covered by this standard shall be designed and constructed for a minimum service life of 20 years and an
expected uninterrupted operation of at least 3 years…”

If this can be done in the reciprocating air compressor, why not the steam engine ? Come on people 1995 was long ago. Oil free design brought the reciprocating compressor to the top of the heap when it comes to efficiency, reliability and flexability. Back when API 618 came out, oil free compressors were running up to 350 bar.

There are certain combinations of components that must be choosen for their compatability, with each other the fluid being pumped, and component speeds. The tempatures of operation are a consideration for self lubricating components also.

Spilling is still going oil free (since 2003) and their web site lists inlet pressures from 6 to 60 bar, but I don't see any informationon service life. I do know their engines are good for at least 1500 rpm.

Peter Heid

Peter Heid
Re: Enginion Steam Engine Oil Free Cylinders
December 30, 2009 05:15PM
There was an article in the Steam Automobile about Enginion in 2002
Re: Enginion Steam Engine Oil Free Cylinders
December 31, 2009 10:26AM
Has anyone tried electrostatic chrome for the cylinder wall and No. 35018 Malleable (semi-nodular, contains rounded nodes of free graphite) for the rings?

charles
Re: Enginion Steam Engine Oil Free Cylinders
December 31, 2009 12:19PM
Hello,

According to the article the Enginion engine used a proprietary coating on the cylinder walls and carbon composite for both rings and piston. In their patent they tried to cover every ceramic element under the sun. There are plenty of companies which make some very advanced and economical coatings that are harder than nitride but not diamond. These coatings would need to be non rusting for a water lubed engine. They would (I think) also have to be honed or finished to a very, very smooth polish so as not to wear the rings.

The rings, regardless of material would have to be something which would be flexible enough to conform to the cylinder wall out of roundness to make a seal, same as IC practice. Composite carbon/fibre rings can be made and would be flexible enough to do this job. For most materials the wear rate is related to the friction and frictional pressure, so ring design comes into play here, as the force behind the ring by steam pressure determines the frictional force. Now graphite has sliding properties but these depend upon some H2O being present in the graphite.

When the temperature is too high this water will get driven out and the friction/wear will go up. A modest amount of water fed to the rings should keep them slightly cooler and hydrated, I would guess. The carbon compressor rings with the lowest friction and wear also contain Antimony (Sb).

Other bearing materials such as Toughmet might actually do better. This is a type of bronze, but has some advanced properties and lower friction than some. A ring material should be capable of not only sliding with low friction and wear characteristics, but also it has to be formed to seal well. This means following IC practice in the sealing department, which means being able to machine similarly.

Much thought needs to go into oil-free operation as far as ring/ cylinder combinations but setting up test engines and running various designed combinations under the stress of temperature and pressure is the only way to get to the answers we want.


Best, ------- Bill G.
Re: Enginion Steam Engine Oil Free Cylinders
December 31, 2009 01:49PM
The oil free cylinders used on reciprocating air compressors are still cast iron, usually with no coating. This material is used no matter what they pump, even air with moisture. Grey cast iron is used and if it is a corrosive environment, ni-resist or austenitic type A436 type 2b is used. The hardness on all cast iron cylinders should be at least 200 Hb, and the surface finish should be from 0.4 to 0.6 microns Ra. A polished surface must be avoided.

Coated cylinders have been used but not all have had success.

Carbon rings will not meet the service requirements of API 618 in most compressor applications, and would probably not last in steam service either.

No one has yet to develop a lubrication free piston ring, and I would not look for one anytime soon. Every ring uses lubrication, even if the lubrication comes from the ring it's self.

For piston rods 4140 or stainless 420 have proved successful when hardened to 50 to 55 Rc. Nitrided coatings work well and have a hardness in the 60 to 65 Rc. Hard coatings such as nikisil and tungsten carbide have been used with some success but many failures also. The piston rods are normally given a surface finish of 0.2 to .03 microns Ra, but for hardened surfaces it is normally 0.1 to 0.2 microns Ra.

Reciprocating compressors are designed with piston speeds usually below 4n m/s, and ring temperatures below 175C.

The means by which self lubrication operates are not fully understood but basically one material must leave a lubricating film on the other material. This is called the Adhesive Wear Mechanism. When the film becomes stabilized it then acts as the lubricant, but if the receiving surface is too smooth, the film will not develop properly. If the surface is too rough, the film required to cover the irregularities is too thick to stabilize. The surface finish required is also a function of the chemical properties of the lubricant, not just frictional characteristics of the materials being lubricated.

I don't believe any air compressor ring materials are suited to the temperatures of a steam engine, but advances are made every day.

Peter Heid
HLS
Re: Enginion Steam Engine Oil Free Cylinders
December 31, 2009 02:35PM
Bill, Peter,
An exellent synnopsis. The important thing to remember is the water quality and the use of non corossive materials. We even has to build our own igniters as the electric field from a spark plug would cause problems. cylinder polish is also important as with water lube it will wash off the material used to dry lube. We have tried most of these and more even the nikisil which rusted. Results are looking very good now, always looking for the holy grail of materials. I met the engineers that worked on the engingion project a few years ago at the Detroit show. They had shut down their project a year before. In some of their tests they were trying to use an antifreze for some lubrication. They were very forthcoming with information but they did say that we were ahead of where they were. a word of incouragement can go a long way ,we got along very well. They were operating at lower temperatures than we are using and did not make as much use of heat regeneration. because of these factors they did not get their efficencys where they needed to be. They did however did have a very clean fuel burn using a ceramic burn tray.
Harry
Re: Enginion Steam Engine Oil Free Cylinders
December 31, 2009 03:38PM
Has any one tried diamond coatings or diamond like coatings?

[www.diamondcoating.net]
Re: Enginion Steam Engine Oil Free Cylinders
December 31, 2009 05:10PM
API 618 would be nice, but I was working under a different set of assumptions: a hard surface cylinder with the lube material in the rings. The theory being that it is cheap to replace the rings during the yearly inspection as long as the cylinder wall is not scored. Let the rings be cheap and easy to replace. In a DA the piston stays free from the wall so (in theory) will not score the cylinder. I simply loose power as the rings fail and leak.

I assume that graphite is easy to remove from resurculating water and will not harm the boiler.

The texture of the cylinder coating is new consideration for me. I wonder if this can be controled in the electroplating or manufacturing process.

In the back of my mind, I think that the ends of the cylinder is running very hot while a few inches away, at the exhaust, the cylinder is relitively cool. a differance of 500 degrees or more! I asked the boys down town here about ceramic on the inside wall. The ceramic that they use is too rough and would not work. I did not persue the subject with them any further. I suppose that there are many differant types of ceramics, but not at this shop.

If it were easy, someone would have doed it already.

charles
Re: Enginion Steam Engine Oil Free Cylinders
December 31, 2009 05:35PM
Hi Brent,

Quote
Brent Laird
Has any one tried diamond coatings or diamond like coatings?

Yes but only once, seems to me, there was a reference in regards on a thread about a parabolic dish receiver, steam engine system. The reason for selecting a coating like this, it had to do with, thermal heat transfer, in other words, diamond conducts heat better than copper, or copper aluminum oxide(cu/sappire).

Ive had some brief mentionings with Harry related to his condenser, as a coating for 4011 alu.

best

Jeremy
Re: Enginion Steam Engine Oil Free Cylinders
December 31, 2009 09:27PM
Hello Brent and Jeremy,

From my studies of DLCs they can give very superior low friction properties and almost zero wear. The problem is, like graphite, that these coatings depend on a water vapor attaching to the coating and it is the water that actually does the lubricating. There are two different types of DLCs. One works better with oil and one works better dry, but I forget which is which. It has to do with how water attaches to the surface. If the surface temperature is low enough then the water will be there and if it is too high then it won't and the lubricating characteristics will change. Many of these surfaces will still attract a water layer to them at slightly above saturation temperature, but not too much and each would have to be investigated for this.

Many of the surfaces which are self lubricating and must leave a trace of the same material on the opposing surface as explained by Peter Heid above, still require the water molecular attachment. So any dry powders which work in space (vacuum) and can take the temperature may be worth investigation. Remember, dry steam is really dry, and unless the cylinder wall is getting near to the temperature of condensation, any coating which requires molecular water can be dried out.

The big factor to consider also is that piston ring/cylinder friction is a large part of the engine friction issue and hydrodynamic lubrication is the road to the lowest friction.


Jeremy, what was the issue of needing a coating on Harry's condenser other than an anodize? All the condenser surface needs is a good smooth surface that conducts heat. I sanded a copper surface to see if roughing it up would help by presenting more micro surface area to condense on. It didn't work as it just held the water film in place. Condensing water is just not a micro process as one would think.


Best, -------- Bill G.
Re: Enginion Steam Engine Oil Free Cylinders
December 31, 2009 10:06PM
Hi Bill,

Actually, I was trying to sell Harry the coating as a sublet vender, we had some private meetings about it, what was determined in the end, was that, cost-wise Harrys well off enough, just using anodizing, which is a sappire.. So, he is already using a surface thermal enhancement on the surfaces of his condensers.

best

Jeremy
Re: Enginion Steam Engine Oil Free Cylinders
December 31, 2009 11:28PM
[www.moldmakingtechnology.com]

According to this tool site steel at temperature iron/steel tends attract carbon. so your diamond coating dissolves chemically over time. However, for other metals it may work.

Diamond is a good conductor of heat (diamonds are called "ice" because they feel cold to the touch because they are conducting the heat away so good). ignoring the costs... Coating the boiler/condenser tubes may improve the effectiveness of them.

Of course the coatings have to stand the operating temperature.
Re: Enginion Steam Engine Oil Free Cylinders
January 01, 2010 07:37AM
Harry,

There must have been something wrong with your Nikisil coating if it rusted. I have been working with Nikisil since 1983 and I have never seen the coating rust or chemically change. Nikisil's only enemy is abrasive materials, it will wear. In an IC engine that sat in the rain for years, with the cylinders filled with water, the Nikisil coating was perfect.

Many companies have struggled to plate iron cylinder liners, and will only work with aluminum. The process for plating iron has been sorted out in the last couple of years.

I suspect that you had porosities in your coating that exposed the iron below. I highly recomend aluminum cylinders if you are going to use a nikisik plating. Unless you are 100% certain of your suppliers abilities to plate iron, the coating may not be perfect. If an aluminum cytlinder gets destroyed physically, you just weld it up and plate back over it, not an option available with iron. It is also a good place to reduce engine weight, and aluminum castings are usually cheaper than iron.

Peter Heid
ben
Re: Enginion Steam Engine Oil Free Cylinders
January 01, 2010 09:47AM
Hi,,,Will the alloy take the superheat,, Two issues,,,strength,,and expansion,// ring fit,???,,Cheers Ben
Re: Enginion Steam Engine Oil Free Cylinders
January 01, 2010 12:40PM
Ben,

The cast iron types I mentioned are no problem for the temps encountered, and every hard coating method I am aware of will take the heat. Expansion and contraction are not a problem for most hard coatings, they do not have a problem following the changes. Nikisil can take higher tempatures than the base metals in most applications.

Harry,

I was thinking about the rust issue and I think it might be possible for rust to occurr in a properly coated iron cylinder. The reason the Nikisil coating can undergo expansion and contraction without destruction is the fact that it is welded to the surface, and under the microscope it is not one solid piece but millions of individual particles. The surface is probably slightly porous and the water could get to the iron, but the Nikisil won't rust.

Peter Heid
ben
Re: Enginion Steam Engine Oil Free Cylinders
January 01, 2010 02:50PM
Hi Peter,,,It was the alloy cylenders I was thinking of,,,re,expansion and strength at elevated temp,,,Cheers,,,Ben
Re: Enginion Steam Engine Oil Free Cylinders
January 01, 2010 04:19PM
Aluminum/nikasil looks to be a worthy pursuit. Wonder if the ceramics will stick? Be a nice piston dome covering until it delaminated due to expansion, flex or something else. Babbit Bearing in San Jose does a lot of hard chrome, ceramic coatings, and plasma sprays..wonder if they do nikasil..doubt it. Will call them. Good folks, been around a long time. Did some hard chrome precision honed cylinders for a filler machine I built in the 80's. Good quality stuff.
Re: Enginion Steam Engine Oil Free Cylinders
January 02, 2010 06:46AM
Ben,

There are alloys of aluminum that will work well in the steam cylinder applications.

K,

Ceramic coatings on pistons, valves, cylinder heads, and even valve springs will not delaminate if they are a quality coating and applied properly. The company we use started their life working for NASA and now they really hit the racing market. They do coatings for heat and for wear surfaces. They have a thick coating (0.030 inches I think) for heat that is the best for exhausts and such.

Peter Heid
Re: Enginion Steam Engine Oil Free Cylinders
January 02, 2010 02:08PM
Hello,

Is there any information or conjecture on the use of high silicon aluminum (23%) for use as cylinders?

Thanks, --------- Bill G.
Re: Enginion Steam Engine Oil Free Cylinders
January 02, 2010 02:57PM
Do you mean the silicon carbide coating? Look up the nicosil, used all over. Susuki uses a proprietary form in all the high power motorcycles. Think wiki lists users, porshe, citroen etc. If your meaning the high silicon content aluminim, which I think you are after digesting better: [www.keytometals.com]
Re: Enginion Steam Engine Oil Free Cylinders
January 09, 2010 01:22AM
Has any one looked at super hard steel?


[newsdesk.inl.gov]

Quote

Researchers create the Super Hard Steel coating by transforming steel alloy into a non-crystalline metallic glass.

Quote

Super Hard Steel has hardness properties among the highest ever reported for any metallic structure or alloy-up to 16 giga Pascals. In comparison to existing high performance coatings, Super Hard Steel is significantly harder than electrolytic hard chrome and approaches the best tungsten carbide. In an independent, standard abrasion test, Super Hard Steel actually wore down the hardest commercially available pin material, silicon nitride, which is used to develop wear scars on hard coatings. The extreme hardness of Super Hard Steel in conjunction with its metallic bonds gives the material abrasion wear resistance properties that Branagan believes will significantly improve the lifetime of coated machine parts. The unlubricated material also exhibits a low coefficient of friction in the range of lubricated steel, another property that can be exploited for a range of applications.


Nanosteel is the company spun off the Idaho Nation Lab to develop this technology.
[www.nanosteelco.com]

From their web page the white paper tells of coating boilers tubes in coal fired plants to prevent corrosion and erosion problems. Another white paper replaced chrome in hydraulic rams.

My wife personally knows one of the metallurgist at that company. I think I will ask her some questions about it in steam engine applications.



Edited 1 time(s). Last edit at 01/09/2010 07:33PM by Brent Laird.
Re: Enginion Steam Engine Oil Free Cylinders
January 09, 2010 05:02AM
Nice information Brent.
Re: Enginion Steam Engine Oil Free Cylinders
January 21, 2010 02:57PM
Hi folks, very interesting topic. On saturated steam water is the lubricant. Going on very large diesel practice with cross-head type engines the liners are separately lubricated using dedicated mechanical lubricators. Some large trunk type engine are also fitted with liner lubrication, one I had experience with had over 120,000 hours on some of the original liners with the honing marks still visible. The designers of these engines go to great lengths to ensure that the liner temperature in way of the rings is low enough for the lubricant to survive and do its job.
I suppose if water is to be used as a lubricant then the liner coating and the ring coating would have to be suitable for water lubrication. But the water has to survive as water not steam to act as a lubricant. I suppose this is why Doble tried cooling on his HP cylinder in the Ultimax engine.
I have not come across the idea of using a mechanical lubricator to inject a small quantity of water as a coolant and a lubricant in way of the rings on a steam cylinder similarly to the way oil is injected on large diesels.
Does anyone know if it has been tried?
Would it work?
Re: Enginion Steam Engine Oil Free Cylinders
January 21, 2010 05:26PM
I'm pretty certain Harry's Cyclone is doing this.
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