What about Helium ?

With the current excitement about pebble reactors going on, I was wondering if any other type steam applications have tried helium as the working medium ?

Helium can go to a higher temperature than steam, without the dangerous pressures, and it can hold 1/3 more heat than steam can when it hits the turbine. I think of a closed system like Harry's using helium and from a glance it sounds good. There could be a significant weight savings by getting rid of the water also. With a properly designed boiler a burst pipe is not much of a hazzard, but helium could prove safer. With no change of state from a liguid to a gas, the design of a condenser seems straight forward, and water could be mixed with the helium for cooling without any detriment to the helium, but it may cause corrosion so separation may be necessarry.

High temperature gas cooled reactors (HTGR) have hit efficiencies of 40% in the 1970's

Any thoughts ?

Peter Heid

I have to say it :-)
It's been done it's called a Stirling engine

Yes, I am familiar with stirling engines and pressurized helium systems they use, but they don't necessarly make the best use of heliums benefits. Helium was a huge efficiency gain in the stirling engine and it made it practical for many applications. Can helium be of any benefit to the steam world ?

I have yet to see a steam engine system make good use of the energy that is tied up in the phase change when water goes to steam, this heat is lost at the condenser with only a tiny amount ever conserved. With no phase change in a helium system, it would seem the opportunity for greater efficiencies is there.

It may not be what is going through the engine. A hybrid is an interesting idea, where helium is heated and used to make steam in an exchanger. It is easier to store energy in helium than it is to store it in live steam, there is no phase change to deal with, and the helium would only need to go to a maxium pressure of about 700 psi, and it holds about 1/3 more heat than steam. A helium hybrid system could make better use of regenerative braking than steam alone. Adding more heat to the helium has little effect on the system pressure, so a basic hybrid would opperate with the same helium pressure as a full blown performance version. Safety devices are often simpler and much cheaper when you apply them to a system that handles a gas, than if they are required for steam. Of course, the amount of the steam generated can be easily regulated by the amount of water supplied to the helium / steam exchanger, and when there is no steam demand, the exchanger can safely opperate dry. The exchanger(s) could be inside the cylinder heads to keep the heat in the engine also, which leads to an enclosed system.

I believe the size of the heat exchange device now known as a boiler, would be greatly reduced in a helium hybrid. There ways to excite the helium that impart very little heat to the suroundings which might be an avenue of efficiency also.

No Thought is Too Small

Peter Heid

Helium molecues are denser than Hydrogen so they will give more substantial heat transfer/flux. Why not use H2O. The Stirling is a mechanical/geometric/timing device to compress, heat exchange, expand, heat exchange, etc. with energy pumping in one corner and shaft power coming out another. This is not the only mechanical arrangement. Come see my drawer full since 1965. No thought is too small. Sleep on it.

All the best,

Karl Petersen

Karl,

First I would like to thank you for all you do for the steam hobby and it's crazies. It has been a while but you and Geroge Nutz sparked my interest in steam and welcomed me to this world. Not only do you share your experiences and insight, but you are also diplomatic and kind.

Mainly I post things to provoke thought, I don't expect anything will come from the points I make except new ideas or maybe new ways to use old ideas.

I like the thought of not losing the heat of vaporzation with helium. If you got 1/3 more heat storage capability and don't lose anything because of phase change, the gains would really help efficiency. When you don't have 2 phase flow, such as with an ideal gas, the design of heat exchangers like boilers and condensers is much easier. If oil is used for lubrication, it is easier to separate from an ideal gas than steam or water. For the best helium performance the optimum pressure is far below that of steam.

I would love to see your collection of Stirling engines, and most everything you have collected over the years.

Peter Heid

Peter I still don't get why you think helium has anything to do with or is any of use in a Rankine cycle engine which by definition uses a condensable fluid.
If you don't condense the gas to a fluid in the cycle then again, by definition, you must talking about a Stirling or Brayton cycle which have their own fascinations.

Cheers

Helium is not "steam" and therefor off-topic here but could be discussed in the Technicalities section.

However the D-cycle is a heat engine that runs on steam in compression and expansion without condensing as in the Stirling. It is not constricted to the geometric relationships of the Stirling engine, but the events are separated much as James Watt separated the condenser from the piston/cylinder of the Newcomen engine. This has been invented many times, and the "drawer full" I wrote of are some of those designs. If anyone has the real hardware lying about, I would be delighted to have it for my drawer. It would be nice to think I could make my fortune by making them practical.

Thanks for your kind words, Peter.

Karl Petersen

Mark & Karl,

As I said, the discussion is just for the exploration of ideas. Even though the Stirling engine is often discussed here, that was not my intent, and I did not bring it up.

Helium has properties that may make it suitable for use in a steam system including including the fact that it holds more heat, it will not normally freeze, it is easier to store heat in helium, heat exchanger design is more straight forward, the pressure at which it holds it's maximum heat capacity is at a much lower pressure than steam, it even weighs less than steam.

There has been much discussion about freezing in steam systems and possible remedies. Do I need to tell everyone that you could use a small helium circuit to melt the frozen steam system and ready it for use. (Makes me think of my refrigerator with nitrogen and ammonia in a small circuit)

Hybrids have been discussed for steam systems and helium would require a much lighter heat exchanger than steam and the helium to steam exchanger probably would fit inside a steam engine, like a hot head.

If there was helium in your hybrid, you could preheat the engine with it before steam was introduced, with no pesky condensation.

I am not saying we should build Stirling engines, but maybe some innovations and technologies can be brought to the steam world from any other direction.

Remember an open mind lets ideas in and out.

Peter Heid

Hi Karl,

your mention of the D-cycle perks my interest. Harry has refered to this cycle when discussing engine cycles with me. I have never confermed what the cycle actually is, any leads you could provide would be welcome.

Best

Jeremy

Still don't get it
Helium lacks one property, it doesn't condense, and that makes it unsuitable for Rankine cycle systems.

Adding another heat transfer loop to a steam system doesn't appear to be a way to increase efficiency.

Helium has much less heat storage capacity volume for volume compared to hot pressurized water as there is no latent heat of condensation.

If you are going to introduce a non condensable gas into a steam circuit (Note the D cycle doesn't) then for the purposes of easy experimentation why not use air? It's heat capacity and transfer rate is worse than helium but not hugely.
You'd be turning the vacuum pump off on the steam circuit off of course. ;-)

Open minded? Sort of, but when introducing ideas you have to be be prepared to justify and debate those thoughts

My favorite quote for that great curmudgeon James Randi "Don't be so open minded you are mistaken for being empty headed "

Hi All

Quote
Marksteamnz
If you are going to introduce a non condensable gas into a steam circuit (Note the D cycle doesn't) then for the purposes of easy experimentation why not use air?

I have done this with a four-cycle steam engine, it does make a difference, but strictly speaking superheated steam works better.

I just did a search on D cycle, I must say, alot more turned up since the last time I tried this(a search) nevertheless it seems to be a methodology directerd towards internal combustion? see links-

[www.yanengines.com]

[repo-nt.tcc.virginia.edu]

[green.autoblog.com]

Also, considering this, if the D cycle is not a rankine cycle then what is it?

My work directed towards flash steam engines or most recently coined "de-superheating flash steam engines"[the engine must be 4stroke with both intake and compression strokes to do this] The question is, is an engine that conserves heat thru re-compression(to enhance heat transfer) when water is injected into compressed superheated steam, The reason Im calling everything thats being said into question... Is , does de-superheating fall under rankine cycle classification? or what? I seem to remember an obscure reference to White or Serpollet using a water-injection device in a superheater, to compensate for reserve capacity with a monotube generator, and this was /classified as a bad way to do it becuse it was considered a overall loss to the system. Was that, determined thru traditional rankine cycle analysis, if not, what are the grounds for stating superheating, and consequently de-superheating should even be classified as a loss to efficiency?

Best

Jeremy



Edited 1 time(s). Last edit at 12/20/2009 04:17PM by Jeremy Holmes.

Hi I am new here.

Just let me post a few links and let other comment if they choose. My interests are more towards nuclear reactors and I became interested in steam when some one posted on the forum I visit ( [thoriumenergy.blogspot.com]) that some motors in commercial nuclear plants are steam engines. The reason is, if you are generating steam anyway why not use it first as steam instead of converting it electricity, and then drive a large electric motor. There may be other factors such as a nuclear plant lasts 60 -80 years and if you loose commercial power you still have a steam engine( which may be critical) running on plant steam.

Concerning helium cooled reactors( really a kind of steam engine). I believe they are talking abou the Brayton cycle. They don''t have to use helium. It could also be nitrogen or carbon dioxide.

[en.wikipedia.org]

[www.inl.gov]


Brent

One other scenario using spent nuclear fuel, that departs from a Brayton cycle is the idea of an heated piston steam engine, normally the piston engine is of small to moderate displacement, and runs without refueling, since the the primary heat source, is fixed in the piston. The problem is the engine must be built in such away, that its reliable unuff to operate thru its life cycle without servicing. Such apperatus has been proposed for Yucca mountain, however is stalling under the current idiolgy'/political climate.

Jeremy

Mark,

"Adding another heat transfer loop to a steam system doesn't appear to be a way to increase efficiency."

I thought some of the most efficient steam systems were binary, maybe I am wrong.

"Open minded? Sort of, but when introducing ideas you have to be be prepared to justify and debate those thoughts"

I don't need to justify anything. I believe the forum is for the sharing of thoughts, not for delivering proof of concept. I put my ideas here, and enjoy the discussion because I am of the feeling that every idea should be mulled over. If someone doesn't like the idea they can skip it or comment, but the justification is left for those wishing to adopt the idea.

"My favorite quote for that great curmudgeon James Randi "Don't be so open minded you are mistaken for being empty headed""

Ideas don't come from an empty head or from a closed mind.

Jeremy,

The Sucderi engine is interesting but it still has hurdles to over come. The SAE has reported that 26% of the hydrocarbon pollution from an internal combustion engine is from the oil on the cylinder walls. If the Sucderi engine is run in pumping / engine braking mode you will have to have have the power exhaust valve open to prevent excess cylinder vacuum or the hydrocarbon emissions will climb. If you open the valve and pump the gasses back and forth, you loose thermal efficiency. When the engine is running off of compressed air you need to hold the pumping inlet valve open so the you don't get unwanted engine braking, and the same trouble occurrs.

As far as pollution, the most efficient and cleanist burning fuel injection systems rely on having little or no turbulence to spread the fuel under low loads. The fuel required at low loads is less than can be used by the volume of air required to fill the cylinder so the fuel is injected into the combustion chamber in a tight ball to insure complete burning. Any fuel that gets mixed with too much air will not burn clean or fail to burn at all. It looks like the Sucdari would work best under a heavy load, not idling.

The extra friction and the extra costs may be a hinderance. I like the 2 stroke versions better.

Ideas are like trees, they come from many roots, have many branches, and they can spread seeds.

Peter Heid

Quote
Jeremy Holmes
One other scenario using spent nuclear fuel, that departs from a Brayton cycle is the idea of an heated piston steam engine, normally the piston engine is of small to moderate displacement, and runs without refueling, since the the primary heat source, is fixed in the piston. The problem is the engine must be built in such away, that its reliable unuff to operate thru its life cycle without servicing. Such apperatus has been proposed for Yucca mountain, however is stalling under the current idiolgy'/political climate.

Jeremy

I personally put some thermocouples on some commercial spent fuel casts in about 1984. The outside temperature in the Idaho summer was 155 degree F. It might get hotter if they insulated it. It had lots of cooling fins on it. It is most likely designed to cool down naturally so trying to recover the waste heat will be difficult.
What would be the design life a this steam engine? The lower the heat source the greater capital expense in trying to recover it. Besides yucca mountain will never open.

Better to take that spent fuel and use it in another type of reactor. Much of the spent fuel assemblies still have a large amount of unspent material in them.

Don't you have to consider in any steam engine the condenser side ( the cold )as well as the boiler( the hot side). That is what makes nuclear submarine steam engine so good. You have the ocean to cool the condenser and the nuclear reactor to provide near instant steam.

Brent

Hi Brent,

First off, welcome to the forum.

Quote
Brent Laird
Better to take that spent fuel and use it in another type of reactor

Yes such as breeder reactor.

Quote
Brent Laird
I personally put some thermocouples on some commercial spent fuel casts in about 1984. The outside temperature in the Idaho summer was 155 degree F.

As you get a chance, look up RTG at the JPL website. I hear what your saying with relation to Delta T (thermal temp offset)(condense) and controlling humidity in the Yucca mountain storage facility, is a huge proplem, since corrosion can breach the storage containers rapidly, without humidity control/refridgeration.

Its a good thing the casts you were putting thermocouples on, werent any hotter than what you say, since it would be illiegal to transport them, with any higher reactive level.

Funny that you mention that. Last I heard, they start to pull fuel rods when they make less than 650*f. Then ov-coarse there placed in a off-line reactor, thats stored onsite, under water, untill levels are extracted/depleted so that they can be safely transported. Has anyone ever told you, that coal burning power plants always run hotter than nuke -plants...

Our design team has Emeritus from the US NAVY, working with both subs and AC carriers. Your talking to a guy that provided some specialized tools to repair a geiger counter just a few weeks ago.

Jeremy

I feel its important to suppliment my reply alittle.

When Im reffering to the "hot piston steam engine" this comes from an article in popular mechanics or popular science not sure which. The article was printed in the mid-90s. It was about a nuclear scientist perusing his PHD, the thesis involved, a modified briggs and stratton engine, with an electric heater mounted on the piston. He also was the one, who suggested the use of spent nuke fuel to run a piston steam engine.

I found the article fascinating, I have been working towards building a flash steam engine for many years.

To me, the electrically heated piston engine, was one of the first confirmed running flash steam engines to have ever existed.

In the inital stages of development with the electrical valve gear, that was developed by me, we had concerns about EMF emissions from the solenoid, that was being worked with. We allowed a (board certified)Heath Physicist to take measurments of various configurations that we were working with. Everything was determined to be "way" within safety margins. This fellow was highly impressed with the work that were doing with the flash steam engine, so he opted to become part of the design team.

More specifically, this should give you an idea of our Aim with the project.

[www.flashsteam.com]


Its some shameless advertising on my part(not really but anyway) so that any wild ideas can be contained....

Theres a very large knowledge base that were tapping into, but its needed to accomplish the task.

Best to All

Jeremy

"I believe the forum is for the sharing of thoughts, not for delivering proof of concept. I put my ideas here, and enjoy the discussion because I am of the feeling that every idea should be mulled over. If someone doesn't like the idea they can skip it or comment, but the justification is left for those wishing to adopt the idea."

Sorry I don't agree. Ideas that get put on here that are unclear, poorly thought out or just plain wrong are noise, disinformation etc should not be posted. If you can't defend your steam idea, clearly explain how it ties into main stream science, or ask a question to refine your own thinking etc then it's just an irritation.

If you want to see an example of unfettered brain outpourings at there most wretched re read, Amish man, the twit with the reciprocating engine controlled by a clock escapement, Lee Hall Jnr etc. Just a waste of electrons.

Your original posting re helium made no sense to me as helium is non condensable. I'm just asking how it applies to steam and you have ideas as a heat transfer improver but your examples are inapplicable as I understand it. All the binary systems (two heat transfer fluids in the same circuit??) I'm aware of still use condensable gases ie water ammonia.

I really can't see how helium in a rankine cycle can be applied.

Quote
Mark Stacey
I really can't see how helium in a rankine cycle can be applied.

Well it can, sorry to give you the bad news, seems to me you dont hesitate to support Harry as an example, furthermore your mention of Amish Man, in the context you used, is rude...

If YOU get pissed off at my reply here, I could really care less, Mark. You not justifing anything with you comments, I guess it takes all kinds. But fer sure, your not a good advocater for anyone with your attitude, and towards Peter H.

I was hopeing Brent would chime back in.. but your reply, infers this is a useless topic.

I put some work into my replies, I guess you dont have to do that, because you live in a crystal ball.

Quote
Jeremy Holmes

Quote
Brent Laird
Better to take that spent fuel and use it in another type of reactor

Yes such as breeder reactor.

Quote
Brent Laird

I personally like the concept of a liquid fluoride thorium reactor( LFTR). By its nature it breeds u233 from thorium using a neutron source such as spent nuclear fuel. The core can not melt because it is already a liquid. It cannot have a steam explosion because the coolant is a liquid salt. It therefore would not require pressurized vessels. Its transmutes all of the fission products left in the spent fuel without reprocessing. One by product is you can get fission products out such a plutonium 238 which are used in RTG. This isotope is very expensive right now and comes from Russia.

[en.wikipedia.org]

check out the glowing red doughnut.

Wouldn't it be sweet to have a 1000 degree C heater on all the time generating steam.

"I put some work into my replies, I guess you dont have to do that, because you live in a crystal ball."

Jeremy I couldn't see in your or Peter's replies any mention of how Helium in a Rankine cycle could help, be of use or even have any connection and I've expressed that three different ways. So far all i've got is a pasting for asking for a link. If you saying I'm not allowed to ask or criticize an idea I certainly won't bother again. Enjoy floating speculations with out criticism.
Cheers

Hi Mark,

Take a quick look at this link-

[geothermal.id.doe.gov]

The only reason, im saying what im saying, is because You placed A M as un-teachable. A Good teacher, would focus efforts elseware.

So yes, you could say Im telling you that, you dont give things much of a chance, to evolve, in general.

Lets take the "Law Of Conservation Of Energy" fer-instance, Its really not that much different of trying to teach someone in the 3rd grade, the 2nd Law of Thermodynamics, of-coarse they got question 14. wrong on the assignment, does that give you the right to fail them for life?

Jeremy Holmes

Mark, You are right ON. You havn't got a Rankine cycle without condensation. On the other hand we do talk about other cycles, from timt to time.

It should be clear that Helium wont work in a Rankine cycle unless you are in a much colder place. Or you have a way of transfering energy to another universe, With that you could have a Helium steam engine runing at ambiant temperature. But you would have to have a way to keep the energy transfer device from sucking all the energy out of our universe. Remember that Stargate Alantas episode. Of course it might just rip a hole in the fabric of space time.

Oh wait. Thats not science. It's science fiction!

Andy

Link looked at and hopefully I've got this right paraphrasing it refers to "How to remove non condensible gases from a binary rankine cycle to improve performance"
So you as a better teacher than me will have to explain to me how that link relates to adding helium (a non condensible gas) to a Rankine cycle to improve performance.
Take your time I'm going to be away for the next 5 days of the Christmas break.

Mutually exclusive..rankine cycle has condensible gas or it isn't rankine..but I think it was also mentioned that the helium could be used in other areas of heat exchange rather than the just the rankine working fluid. Throwing this reply out mostly just to get a better understanding of where this thread is. About 50 or less digested. Better go read the link now

Interesting read. What I got out of it is that either 1, the system is not steam powered but run on VOC's or 2, they don't care if VOC's stay into the steam system.



Edited 1 time(s). Last edit at 12/23/2009 12:49PM by kdc2.

Hi Mark,

That was my way of saying, technically you are correct, you do know what your talking about.

Perhaps, citing a external reference that basically supports what your point is, would be more effective then just arbitrarily kicking someone to the curb.



Best

Jeremy

Wow, all I did was ask if helium had been used in conjunction with steam.

Do I have to justify a question ?

Prove that helium can't be used to advantage in a steam system, since you have the answer, justify it !

If you don't see how an idea can be applied, it doesn't mean it is useless, or doesn't belong in this forum.

Now what was that about open minded again ?

Peter Heid

I think you have a good thread going Peter. Why the wow and which reply got you there. Hope not mine.

Please excuse the delay in resonding to the question on the "D" Cycle. I have been travelling and away from my computer. The "D" cycle was eponymous and so named by John Gordon Davoud and numerous patents including # 3,716,990 were issued. Davoud gave many presentations at steam meets, mostly at Greensborough, and no one ever understood what he was talking about. Similar work was done by Walter Tinker and patent # 3,877,231 is an example of his work. What they were both trying to do is to use steam without condensing it. This is a worthy concept and it is a shame that it does not work. The theory, as I understand it, and always remember that I was a history major in college, is that there was basically a compound engine. The HP cylinder worked just like a normal steam engine on the down stroke. It was uniflow so about 2/3rds of the steam was exhausted. When the rest of the steam in the cylinder was recompressed it heated up, which is the whole secret of the Williams, also eponymous, cycle. Davoud and Tinker figured out some complex way to keep the temperature the same during the compression stroke. They injected water a little at a time just enough to absorb the heat of compression and just enough to flash into steam. Therefore not much work was done during the compression stroke. The saturated steam was then exhausted into a superheater and into a larger diameter LP cylinder. either Davoud nor Tinker were able to explain what they were doing in English, which may have added to their mystique.
People who have attended the annual September meet here in Michigan will remember that two years ago I invited Dr. Bob Bourque to give a presentation. He had patented a quadruple expansion piston engine with re-heat between stages and gave that presentation. I have since located an engineer, not a club member, who has spent years working on a triple expansion piston engine with inter-cooling between stages. I am trying to get him to come to the meet to give a presentation. I think that steam power demands symmetry.
On another topic, and one that this thread has emphasized; I wish that the participants in this phorum would engage in a little more public civility. SACA is not responsible for what is said on this phorum as many of the participants are not club members. Even if they were club members we would have little control over what they say. It should come as no surprise to anyone that there are both many different opinions and many different levels of sophistication within the community of steam people. We should be able to deal with the unsophisticated new steam person; after all, we were all there once. Good steam knowledge is difficult to find. Almost none of it is found on the internet. Those of us in the club and with access to good steam information should figure out some way to get that publicized. Thank you. Tom Kimmel

Hi Tom,

This is the info ive been looking for since Harry first mentioned the D-cycle to me. By the way, I hope that Harry is doing well with his efforts, I think he is invloved in a big project reclaiming waste heat. Im sure he will be around to give us some updates on the Cyclone engine thread as he gets the time. I always enjoy reading about his progress.

Searching for US patent 3,716,990* has lead to a cluster of patents in this area.
4,249,384→Harris
Harris←3,568,444
Davoud←3,772,883
Davoud←3,798,908
3,877,231*
This is the lead that I was looking for, thank you Tom. I have a feeling this will keep me busy in research for sometime. I feel some of the formulas Ive been searching for, are in these documents.

Best

Jeremy Holmes