Steam vs Electric

I have a friend who works for Nissan Motors. He tells me that we steam guys have it all wrong. He says that their all eclectic vehicle called the Leaf consumes only .32 kw-hr/mile at 60 mph. For a typical electrical rate of 10 cent/kw-hr, the operational cost of the Leaf vehicle becomes 3.2 cents/mile. He also makes the point that my most advanced steam powered vehicle will demonstrate no more than 28 miles/gal. With diesel at $2.90/gallon, this works out to be 10.35 cents/mile. Does anyone know the down side of these all electric vehicles other than a relatively short driving distance between charging?

jerry

I honestly haven't looked too far into electric vehicles as a whole, but I hear they seem to require large battery banks. Not only are these cumbersome, but I also hear that they're costly.

In my opinion, when it comes to alternative sources of power, it depends on what YOU want out of your vehicle. For some people, electric works, for others, gasoline, and for us, steamers. They all have their benefits and drawbacks.

But as long as we're on the subject of electricity, the steam car I have been designing is a steam/electric hybrid. However, the electric is only used when the steam generator's pressure is under a certain point (around 600 PSI), so it is used only for a few minutes upon starting (or until reaching that 600 PSI- this time, I can imagine, varies). This should allow the operator to head off almost immediately upon starting the car. After the electric drive switches over to steam, the alternators re-charge the batteries required to power the electric motor(s).

Jerry,

The EV paradigm is way more mature than the all steam auto. I have been following all electric cars for many years. We have yet to see the true state of the art. The high voltage motors under the current trend, will be superseded with a low voltage design. Although lithuim batterys are nice, they too, will be eclipsed by silver-iron batterys.

I remember attending a WEVA congress many years ago and BMW had this abolutely beautiful convertable 325i all electric car, people were lining up, with open check books, but BMW said no way. There is a tremendious market desire for the EV, its just got to look and function like a real car.

When road taxes are considered there just as expensive to run as anything else. Also an over-night transition, would overload the utility grid, the extra power will most likely have to come from the biomass industry, as cogeneration becomes more profitable, possibly using steam engines, after that, there will be no stopping the EV's.

Besides, the idea of me letting my wife drive a steam car, is a pipe dream... Never happen.

Jeremy

Jeremy Holmes Wrote:
-------------------------------------------------------

> The EV paradigm is way more mature than the all
> steam auto. I have been following all electric
> cars for many years. We have yet to see the true
> state of the art. The high voltage motors under
> the current trend, will be superseded with a low
> voltage design. Although lithuim batterys are
> nice, they too, will be eclipsed by silver-iron
> batterys.
>
OK guys, now you're in my world here! Here's some thoughts about electric vehicles most people aren't aware of:

1. Did you know there's an electric motor (used in EV's) out there with an energy conversion efficiency of better than 95%?

2. The electricity produced for electric vehicles comes from powerplants using various forms of hydrocarbons, or even nuclear--but they do it with an efficiency in the 65-70% range (?) so they beat direct use by a factor of 2 or more. Fold in the increasing use of wind, solar--and even the oldest of all--hydro--and you have a pretty efficient energy supply.

3. The battery thing is in a rapid state of development; although lithium is the hot item right now, I believe the future lies in non-battery energy storage currently in early-stage introduction in the form of the "ultracapacitor". Lots of goings on.

4. Hybrid vehicles are popular, but in their most successful iterations (Prius, etc.) don't really represent the state of the art as we can currently do it. Wait until we get hybrids using constant-speed turbo/diesels, or microturbines. Frankly, the Chevy Volt is the best of the current breed because it's a "reverse hybrid" (my own term?)--an electric vehicle that uses a fuel burning engine/gen package to extend the range; wait until the ultracapacitor matures--Chevy can just eliminate the generator pack and fill the void with UC's or UC/battery hybrids. So much happening here.

Having converted a Suzuki motocross to EV, and made a small business out of electric conversions for bicycles, I'm very enthusiastic about the future of electric power. My current project is a roadable "tadpole" trike ( 2 wheels front) with highway speed potential. I love steam, but I think the future is electric.


> Besides, the idea of me letting my wife drive a
> steam car, is a pipe dream... Never happen.

As a part of my steam car project I was determined to allow my wife to drive my steam car to the market and back, without any participation from me. We succeeded in this effort in 1974 (I believe the year is correct--a long time ago!) when she started the car from cold, drove it the 2 miles to the grocery store and back home again without any problems. Makes me kinda proud to this day.

Bill

Hi All

Stationary power plants can be more efficient. There have some impossable clames of 70% and greater. I suspect these are not thermal efficiency.

Then no one has said anything about delevery. There is some line loss. The longer the distance the larger the loss.

From what has benn disscused here on other the thermal efficience of power generation is normally around 40
Yy
Combing line losses conversion to DC for charging and battery losses I doubt an electric can do much better then the 30% that Harry is getting.

I would think that cost of operation is going to be close for for steam, electric and IC.

Andy

Well IMHO if we could build low pressure sodium reactors at home, every one would be useing steam to meet thier power needs.

I've been keeping up with electric cars/hybrids since the mid 70's and will take the power plant efficiency of 70% as VERY hard to believe and even the 60% with a large grain of salt. The current information I gleaned in research from the DOE is that currently over 50% of energy comes from coal power plants rated at approx 33% efficiency. They COULD make them more efficient but it is not considered cost effective as around 50% efficient (from coal input to energy output) is considered the Maximum that physics allows ( I may not agree with this but that is from expert sources). Now as to the COST of the nissan it is possible since coal is a low cost energy provider. Wind, solar, and even nuclear are a good bit more expensive than coal.
Now aside from cost using the best information I can get, taking into account coal based power plants being used, transmission line efficiency, transformer efficiencies, battery charge discharge, and finally electric motor efficiency you get approximately 17-19% of the ORIGINAL coal energy being used by said electric car. This DOES leave out using regenerative braking but a steam car could use a form of that too. So right now a high efficiency diesel is much better on energy useage than an electric car. Not cheaper but more efficient.
Just my $ .02. And please, anyone who has definate data on improved efficiencies of both motors and power plants put this information up so all can verify it. I like to keep up to date and correct any misinformation that I have.

We have gone over this before.
Lithium polymer are the current best in the EV game. Depending on performance you are looking at $14000 or more for a pack. With a five year life once assembled (yes that's right on average FIVE years) and a probable 100,000km of use before they fall over and EV is currently per mile slightly more expensive than the petrol that goes into the SAME performance ic vehicle.
Nice for the warm fuzzy feeling lousy on the pocket.
"Who killed the electric car?" no one it committed suicide.
Cheers

SteveW Wrote:
-------------------------------------------------------

> Just my $ .02. And please, anyone who has
> definate data on improved efficiencies of both
> motors and power plants put this information up so
> all can verify it. I like to keep up to date and
> correct any misinformation that I have.


[www.newsguide.us]

Santa Barbara, CA September 21, 2009 -- LaunchPoint Technologies, Inc. has completed optimization and initial prototyping for a high efficiency, high power density, Halbach array electric motor. With a total weight of only 1.4 pounds, this electric motor produces 7 horsepower at 8400 rpm with 95 percent efficiency. At 5 horsepower per pound, this electric motor has a higher power density than any other electric motor on the market. The brushless, axial flux permanent magnet design is highly tolerant of temperature and centrifugal effects, and the ironless rotor and stator eliminate iron eddy current and hysteresis losses.

Look for more

Bill Hinote Wrote:
-------------------------------------------------------

> Look for more

Question: Where can I find data on electricity transmission and distribution losses?

EIA has estimates for total annual losses related to electricity transmission and distribution (T&D) and other losses in the State Electricity Profiles.

National level data are in the U.S. Total Profile (see link a bottom left of the Profiles page). The data are in "Table 10: Supply and Disposition of Electricity" of each Profile; scroll down each Profile page to find Table 10 and see the row for Estimated Losses in the Table.

To calculate T&D losses as a percentage, divide Estimated Losses by the result of Total Disposition minus Direct Use. Direct Use electricity is electricity that is generated at facilities that is not put onto the electricity transmission and distribution grid, and therefore does not contribute to T&D losses. In 2007, national-level losses were 6.5% of total electricity disposition excluding direct use.

[tonto.eia.doe.gov]

Bill Hinote Wrote:
-------------------------------------------------------

> Look for more

This motor achieves 98 per cent efficiency and is generally accepted as the most efficient in solar car racing. It has a low active component weight (6 kg), and a total wheel weight of 14.5 kg (including the tyre).

[www.csiro.au]

Sounds great on the electric motor efficiency. Thanks for the information! I hope it is durable as well as efficient. I worked in the machine industry with older heavy use electric motors that weighed about 300 lbs for a 10 hp motor. Durable but heavy and about 75 % to 80% efficient at max with 100% duty cycle.
The engine itself seems to be the most efficient part of an electric car. Now if we only had AC batteries. GRYN.

SteveW Wrote:
-------------------------------------------------------
>Now if we only had AC batteries. GRYN.

Where's Tesla when you need him?

All this "i squared R" talk is scary. However, I do know that there are some real new things going on out there with steam. The Stoecker/Langdon team is building an experimental engine based on delayed compression. At the same time the design takes advantage of an effective zero clearance. This cycle will have significant efficiency improvement over the conventional Wiilliams cycle. Also, another effort embraces complete compression relief to the extent that zero clearance can be implemented. If successful, this concept will trump the efficiency of the Stoecker/Langdon engine. Maybe we will hear more about these efforts in the future.

jerry

Jerry,

I believe that the "curse of low efficiency" for a steam engine is lore of the past. That bugaboo just comes up too often as an impenetrable wall. It is always thrown out there as a reason for little success.

Harry's engine is getting reports of 30% overall efficiency at full power. Howard and Toms design show good promise as does mine. My engine for an instance that I know anyway has an expansion ratio of 16 at full throttle and up to about 25 at low throttle. This is combined with extremely fast valving of 15 deg crank. Engine efficiency shows to be 30% at full throttle and 35% at low throttle. Both stages use full re-compression. Add a high pressure first stage and the engine efficiency goes to 42% at cruising speed.

The boiler design also produces its own power to run pumps and turbine and car electrics so those losses should be accounted for.

The main problem with steam isn't the potential design it's more just money, but the perception of what a Rankine cycle can do if developed more fully into an integrated modern vehicle is what needs work. There are several of us here that can do the inventing and designing. It would really be fun to see many of these potential projects get to the finished and built stage.


Best Regards, ---------- Bill G.

Quote
Jerry Peoples
All this "i squared R" talk is scary.

lol, strickly speaking it is "Pie R Squared"

Ok, so theres Harry's engine, Stoecker/Langdon team's engine, Bill G's engine, Peter Brows engine, my engine, etc.

What I would really like to know who is going to be the impartial Judge to define "Engine Thermal Efficiency", "Boiller Efficiency" AND "Combustion Efficiency". Then "Overall Efficiency" of the system. Under what set of empirical conditions?...

I really dont think the Auto (Progressive) X-prize judge panel will have to deal with the conversion for obvious reasons (:ie no one from the steam world would even dare to enter.)

Which brings us back to buisness plans and what Bill G is pointing out, now, CLEARLY Harry is infact exibiting some true genius in this department.

I initally figured UL labs could function as "impartal efficiency judge" but im not sure if this would be affordable.

At some point there's going to have to some sort of body that all the physical engines will have to provide themselves to. And for obvious reasons I dont think it will be the SACA, or should it, nevertheless such a proposed measure will have to be TOTALLY unbiased, I really dont think we have that at this time. Im leaving my mind open to this and have proposed a simular question on my own forum.

Best

Jeremy

Jeremy,

Probably at this point the impartial judge would be as always a lot of hype and the press. I quoted for mine only engine thermal efficiency to keep things clearer. This because boiler and system efficiency can vary too much and the main part of the design work so far was with the engine. By putting steam engines in existing vehicles (conversions) we can get a ready comparison to that vehicles standard efficiencies for whatever figures are out there and probably one of the auto magazines would love to do an article and tests on such a car. That's why I keep kicking around something like a Dodge Caravan as a target type. They are ubiquitous and so everybody knows them. Just beat 20 MPG cruising.

By the way I^2* R = Watts . Current squared times resistance. Bet you knew that.

If all of our projects could reach fruition around the same time then maybe a comparison test would be doable but if years apart due to $ then who knows. Anyway all this $^3 *Sr talk is scary. Sr is social resistance.

Best Regards, -------- Bill G.

What about fuel costs? I undestand everyone is looking to build an efficent motor, but the steam engine is able to burn just about anything for heat source. I saw some where the fuel costs per btu's output of various fuels including wood, coal,propane, and waste oil. Doesnt the lower costing fuels tip the balance in favor of external combustion on a fuel cost per mile basis? Or it the whole Idea to produce the most hp per btu?
Im still new and trying to get up to speed but when your going up against guys with 30 years of experence you will allways be the new kid on the block

This gets rather funny at times. Judging is a waste of time when the judges themselves have not one whit of knowledge about the subject.

Steam? The old Clean Air Car government sponsored programs killed that to a tee. Failure was the bottom line and Detroit saw that. Bob Lutz told me that face to face at dinner one night. They turned their back on steam and it is going to take one hell of a new steam car to even make a dent in that thinking.
Jerry has it right on the button, they think steamers are some dribbling contraptions that cannot make it around the block on one tank of fuel. That image still obtains, right or wrong. Sure there are some good ideas kicking around. So what's stopping them and proving the theories on a dyno? Where is the running hardware?

Who cares what the separate efficiencies are, when what really matters is when the entire system is installed on a calibrated dyno and run as a TOTAL system. The rest is nothing but nit picking by people who like to talk about it; but never actually do anything. Make something, put the ideas into practice and install it in some vehicle, then talk about it. Not accomplished as of yet and the years roll on and on.

The electric cars are nice in town, I had one and liked it and drove a few others, except for a very short useful range then. Go too far and I was creeping along in the curb hoping to God I didn't have to run over a cigarette butt before I got it home. The new ones like the MINI-E are quite nice with good range and adequate speed.
Of course electrics can show good performance. Take a 200 volt motor and dump 400 volts into it an it certainly gets all excited. (Pun intended) Do that for long and smoke appears. I once had a client who fell in love with printed circuit motors when that was the hot item. Put several in a small car (Fiat 600) and found out that there was a thing called cooling that he needed, wouldn't listen either. One very expensive fire and that was that, out of money and investors. Trick motors are nothing new, they pop up on a weekly basis. I think I still have one in a junk box somewhere.

The new exotic batteries work well; but can you afford them? Honest replacement costs are staggering when you include the "recovery" fee. Then there is the fire aspect with alkali metals in a serious accident and the fire department is squirting water on your buzzmobile. Ask your local TESLA sales rep and he turns red with embarrassment, you are not supposed to know about that one. Or now it seems many cities will not grant the permit to have a 220 volt 60 amp line run into a residence, as just reported in Autoweek.
Battery life is very dependent on the number of cycles you want out of it, they do not like cold weather or very hot weather, Li-ion want dynamic cooling when being charged and discharged and on and on. There is a ton of money now being spent on electric cars and not one penny on the steamer.

Locally, and I asked the chief operating engineer, the Moss Landing steam plant is 47% thermal efficiency, with enough regenerative heat exchangers to make even Harry happy. There still are many losses en route to your battery in the car. And, the grids and power sources are not yet really big enough to cover massive use of electric cars if they really were purchased en mass and used every day. It ain't the bed of roses they want you to believe; but they are working day and night on the electric.

The electric gets attention because they are here NOW, you can go out and buy one, quite a few in fact. The steamer does not yet exist, only talk and what Harry is doing.
Is anyone else even trying to put one into serious development or are they just talking about their dreams? The answer is NO they are not.
Then the government inspired science fiction things like hydrogen, CNG, alcohol and such, which only complicates the issue. Pure bio algae or plant fuel oils in the Diesel or in the Rankine cycle engine will do the job if you really want to reduce global warming. We have Diesels, we do NOT have steamers in spite of wanting them.
Me? I fully support Harry, he is the only one out there with something real that I can touch, smell and watch run on a dyno.

Jim

Jim, Tom Stoeker and Howard Langdon's Is in the works and I would bet that a running prototype will be done in the next 12 months. So there will be another contender you can put your hands on soon.

Hi Bill,

I had a really nice reply typed up friday night, then my wifes laptop computer (that I was typing it on) obliterated it, while I was doing a spell check. Im typing my reply to wordpad this time...

"I quoted for mine only engine thermal efficiency to keep things clearer."

This is the number im most interested in. I would like to see 60% as the bench mark, not 33%.

"If all of our projects could reach fruition around the same time then maybe a comparison test would be doable but if years apart due to $ then who knows."

This is why I try to keep an open mind about all this. Im in the process of transitioning out of the state of Florida and into Tennessee, the move will most definity set back development a coupla years. Also im in the process of partnering with the fuel suppliers, again solid fuels. Believe me this is worlds apart from claiming "we can burn anything".

Jim,

"Take a 200 volt motor and dump 400 volts into it an it certainly gets all excited. (Pun intended) Do that for long and smoke appears. I once had a client who fell in love with printed circuit motors when that was the hot item. Put several in a small car (Fiat 600) and found out that there was a thing called cooling that he needed, wouldn't listen either. One very expensive fire"

You once mentioned electrically activated valve gear (I think Besler) you remarked it worked great, until it overheated.. I spent alot of time carfully working out this problem, it also relates to my EV traction motor (which is low voltage and VERY high current) both my valve gear and the EV motor are water cooled. The latter uses centrifugal force to pump water thru the windings (its self pumping using a special fluid transfer slipring arrangement).[already been disclosed to uspto]

As for the Judges, its going to have to be a special group. who knows maybe they will be NASA affilated, but there will have to be some credibilty established no matter who it is.

Harrys already behind the 8 ball, and he's going to have to cut one of his engine's off the leash... Dont get me wrong, I support Harry as I do others, but seeing a "biased evaluation" will not convince me.

At this time I have claimed nothing, yes im working on something, but like ive said before, the type of steam engine (flash) that im working with, no one has even sucessfully built, let alone efficiency claims, yes 60% (engine thermal) would be nice. There are other means to increase engine efficiency other than regeneration, such as conservation. if you would like to see an illustration of this look here-

[www.flashsteam.com]

Thats my engine design and im sticking with it for better or worse, like I said, if it even runs at all, that will be an accomplishment, and if its only 15% thermal efficient so be it. There is about 17 years worth of work behind it.

However when its said and done the efficiency could be much higher since the engine uses conservation instead of regeneration, both will increase thermal efficiency.

You could say the Williams engine uses conservation since it re-compresses exhaust steam. The steam is reused by the cycle "as steam" and not condensed or regenerated.

I hope my tone is not to harsh,

Best

Jeremy

Here's a perfect example of why theres a divide between conservation and regeneration, Harrys engine uses a CRM (compression release mechanism) therefore, as Jerry states, its a "Zero Compression" engine and cannot use conservation. Whereas a "Zero Clearance" engine implies compression of steam, or conservation, yet this does not change the fact, that both types of engine's can utilize regeneration simultanously... Alternately if Harrys engine did not use a CRM and is classified as a "Zero Clearance" engine, it would be able to use "Conservation" as the Williams engine does, since it would not use a CRM in that case. (as the Williams engine does not use a CRM). Last I heard the Cyclones CRM was not adjustable while the engine is running. My engine also uses fixed clearance, I seem to remember Andy as touting the benefits of "variable clearance" using crank-throw as the CRM. According to Jerry, Andy's engine should be Zero Compression if displacement is adjustable.

Jeremy

The thing that always "bakes my noodle" [see "The Matrix" movies] is whether talking about "talking instead of building" is itself "talking instead of building". My engine build has begun too.

Peter

Jeremy,

Yes, Besler used solenoids to run the two steam valves to control the steam flow to the feed pump on the Series F cars. But; the coil was a long way from the hot valve itself with a row of fins on the stem housing. Not for the engine valves however, just that pump.
Warren tried using solenoid valves on that pump once in place of the shuttle valve as an experiment. A handful of light switches on a board run by an arm on the piston rod. The valves overheated and failed, so he said. Probably not as Besler designed them for the feed pump. The normalizer valve was also electric and worked just fine, same design as the pump valve and probably that is where Besler got the design he used. Today it is hard to find a Doble with the original valves.

NASA judges, God Forbid if they were anything like the ones we had to put up with at LMSC. Try people from B & W or Clayton or at least someone who knows steam in general.
Even then, steam cars and their particular demands would be far from anything they ever knew. Let the car speak for itself and run well, that would be enough proof.

Harry's Mk-5 is going out into the real world as soon as the dyno runs are completed and any glitches are fixed. Chuk will get one for the race car.

What would be more than instructive would be one of Harry's engines set up for both zero clearance and no compression and then re-compression. Then let the dyno tell the story.
It is all a matter of development and testing and how much time and money you can spend.

Jim

June 28, 2010 What we are talking about here is economics and not thermodynamics. One of my books says that burning gasoline in a gasoline engine costs 50 cents per Kwh. This includes sales and road taxes. At this time retail for electricity is about 10 cents per Kwh and the marginal cost for coal fired electric is in the neighborhood of 2 cents per Kwh. What is interesting is that the electric car people calculate the cost per mile and then figure it backwards to say that they are getting 100 miles per gallon when they are really getting 20 miles per gallon equivalent using something that costs one/fifth the cost of gasoline. There is such a thing as intellectual honesty but it is no where near alternate fuel discussions. As for thermal efficiencies of coal fired electric, Bob Edwards says that it is 40% at one near where he lives in Tennessee. Crank says 47% and I am not going to get in the middle of that discussion. The efficiency of a stationary power generating plant is because of large scale where heat exchangers can be huge and a river is the heat sink. It is my opinnion that if one subtracts conversion losses of mechanical to electricity at the generating plant, and costs and losses of transmission, and losses in charging batteries, and losses of discharging batteries and then electric motor losses that we will come pretty close to what a mobile steam power plant can do putting steam directly to mechanical motion at the wheels. What is also not being discussed are the external costs of mining and processing heavy metals and the replacement costs of batteries. I had to trade in an electric fork lift, 2,000 pound range, because a new battery pack costs $5,000. Here again, there are intellectual honesty issues. We need to be aware of all of the other possible energy sources because steam power is competing with all of them and everything. However, I suggest that we spend a little more time working on steam engine efficiencies and a little less time on other things. Tom Kimmel

Hi Jeremy,
The dyno tests of the cyclone are monitored By Ratheon engineers the over 30% that was achieved is the total efficency fuel in (BTU) horsepower out with all accessories. The compression is variable as well as the cutoff and a very responsive throttle. Hope you visit before you leave there is a lot going on.
Harry

Jim,

"What would be more than instructive would be one of Harry's engines set up for both zero clearance and no compression and then re-compression. Then let the dyno tell the story."

I would hope that Harry takes the time to do that, it would be most informative. Most likely he is going to persue what works best with the Cyclone design, a respectable position...

Tom,

"However, I suggest that we spend a little more time working on steam engine efficiencies and a little less time on other things."

Steam engine efficiency does start out on paper or by simulation first, then is verified thru testing, if testing verifys the theoretical aim, everything makes sense. Alot of these things are interconnected thru the rules of thermodynamics, making heat engines compatible with alot of cross technology, just as thermodynamics explains heat engines, it also explains combustion and electrical circuits down to the solidstate. It is thermodynamics that explains the maximum computing speed for digital processors. The interconnections are there and are by no means independant.

I was once asked how I process all these factors, my answer was, I use thermodynamics and specific gravity, versa chemistry and atomic weight.

I can understand where Jerrys friend from Nissan is comming from, I submit unless steam car engines can achieve 60% thermal efficiency, they cannot compete with an electric car.

That being said, there are serious drawbacks related to EV technology. The batterys are one, and conversion from heat to electricity is another. This puts the 2 competing classes at par "if" the steam engine has 60% thermal eff. This leaves out practical issues such as designing an electric motor that actually accomodates the right type of batterys(silver-iron), and a distributed power grid.

some very good replies here...

Best

Jeremy

Hi Guys,

Tom thanks for a little analysis on the electric cars 100 mile efficiency. It can be very discouraging to people in the field of alternate technologies to think that the bar has been set 5 times higher than it in reality is. What for instance could we do it the Diesel engines thermal efficiencies were commonly reported to be in the neighborhood of 75% instead of 40%. A goal to shoot for has to be real.

On the subject of re-generation as applied to the automobile engine. In an electric plant the output of the turbines is fairly fixed and certainly doesn't move around much, which allows flows and heat exchanges to reach equilibrium temperatures. In an automobile the temperatures and heat flux through a re-generation system seem like they would be all over the place. The biggest thing I keep running across is that at low throttle or even more short cutoff the temperature differentials for the efficient use of re-generation are less and the re-generation scheme is much less effective at low engine output. A pre-heater using exhaust steam to heat the feed water seems to be a good idea though and this is considered re-generation also.

Most of the re-generation I have studied was for turbines and used a bleed off technique from various pressure/temperature points to effect re-generation. This is hard to do with a piston engine. Also greater efficiency with fewer tricks to get the feed-water up to temperature with a piston engine seem to happen with the usage of an economizer and the whole idea is to use re-generation to get the feed-water up to saturation temperature or as close to it as one can. It would seem to me that re-generation to get the feed-water up to saturation temperature in order to gain efficiency would leave the problem of what to do with the boilers exhaust heat that would have been soaked up by an economizer. This heat would now have to be taken up with an exhaust gases to intake air heat exchanger.

This is an area where the engine efficiency could go up due to re-generation and the boiler efficiency could go down due to a high feed-water inlet temperature to the economizer. Here we get to the efficiency of the overall design as in reality the whole system does have to be taken into account. Apples to oranges though, the engines themselves need to compare just engine efficiency and the boilers just with boiler efficiency.

Has anyone done much study on the use of re-generation with an automobile engine throughout the driving cycle to see what the efficiency differences are?


Best Regards, -------- Bill G.

Bill Gatlin Wrote:
-------------------------------------------------------

> Has anyone done much study on the use of
> re-generation with an automobile engine throughout
> the driving cycle to see what the efficiency
> differences are?

Tongue-in-cheek here:

I'll bet Cyclone have--they are certainly getting a lot of good out of regen, and still managing to have a compact overall package. That's not an easy task IMO.

Bill

FyI, I was at a week-long DOE meeting in Confusion-on-the-Potomac a few weeks ago. They were reviewing some of the current projects they are backing with corporate America, for transportation and hydrogen. To give you an idea of the scale and cost, they were providing a catered lunch each day, for over 1000 attendees, at a Marriott in the Embassy Row area of Washington. Each meal was a serious chunk of my annual salary. And half of the proceedings were hydrogen projects, which in my considered opinion are a total waste of time and effort. A scan of the list of presentations did not show a single item related to steam.

It must be nice to have the backing of Congress.

Tom