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Re: Uniflow steamengine at 20% efficiency in a car project - Today
A very brief lesson on boiling. Note the image for pool boiling modes. The vertical scale is for heat flux, meaning the rate at which heat is transferred from the boiler tube to the water and/or steam. Note that the scale is in factors of ten, so the changes in value are much larger than would be assumed visually. The horizontal scale is the tube wall superheat temperature -- the amount by whby frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - Today
William, You really need to do the math before tossing out ideas. Let's suppose that you need 30 horsepower to maintain highway speeds. (You need a lot more power than that to accelerate up to speed and merge on the freeway --let's not forget hills-- but we'll assume that you can get by with just cruise horsepower). Let's assume that you are pulling a really, really good 8 lbs/hp-hr steam rby frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - Yesterday
Hey Rolly, Beautiful model! This is one of the reasons I don't like the term "Lamont Boiler", this boiler was in service before he was born. Latta and Shawk were using the design before Herreshoff was born. It's hard to tell, but maybe Joshua Perkins was there even earlier yet. I like the fact that you simply refer to it as a forced circulation boiler -- that's honest. Regards,by frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - 2 days ago
Using cool water in a jet (spray) condenser is going to require a lot more cooling water than the amount of water that you will run through the boiler . Think how much water a non-condensing Stanley used and multiply that by 4 or 5. Honestly, there is only one condensing system -- that I know of -- which has the potential to do what you want. This was built by John McCallum and Henry Percivalby frustrated - SteamStuff
Re: start up times - 4 days ago
Rick, the laws of thermodynamics are not thrown out the window with either fusion OR fission. As I noted in my last post "we'll ignore Special Relativity because when that comes up we simply expand the First Law to cover E = mc2". Special Relativity works for both fusion and fission powerplants (whenever we actually get a fusion power plant). In a prospective fusion reactor, two iby frustrated - SteamStuff
Re: start up times - 6 days ago
Doing an energy balance, we find that heat does not make electrolysis any more efficient. I know people who did a lot of electrolysis making oxygen onboard nuclear submarines. The following numbers are just 'fer examples' and not indicative of real-world results: Suppose we feed 1 kilowatt-hour into an electrolyzer filled with cold water. We might get hydrogen production with 1/2 kilowatt-by frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - 6 days ago
The problem of using a tank of very cold water is that you need to first cool off the water. If you want to do that in the middle of the winter, that's fine, otherwise we are back to spending more energy on cooling the water than the power we get from the engine. Anyhow, the idea won't work if you are travelling more than a very short distance. It takes 180.07 BTU per pound of water to raisby frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - 7 days ago
William, You are trying to get something for nothing. Suppose we need to rid the condenser of 1,000,000 BTU per hour in order to condense down to low subatmospheric pressure. You will need to use a 1,000,000 BTU refrigeration unit to cancel out the energy in the steam. The First Rule of Thermodynamics states that we can neither create nor destroy energy -- we can only convert it from oneby frustrated - SteamStuff
Re: start up times - 14 days ago
Trying to do an energy balance, the biggest unknown was electrolyzer efficiency. I finally located a technical presentation online: Hydrogen Production: Fundamentals and Case Study Summaries K.W. Harrison, R. Remick, and G.D. Martin National Renewable Energy Laboratory -- A. Hoskin, Natural Resources Canada https://www.nrel.gov/docs/fy10osti/47302.pdf To quote from the report "…Eleby frustrated - SteamStuff
Re: Trackless Locomotive - 7 weeks ago
As far as a centrifugal pump goes, I may have a couple of suggestions. The most obvious is to inject your cooler feedwater right into the centrifugal pump suction. The cooler water should reduce the chance of flashing (cavitation) and the feed pump discharge pressure should improve the pump suction head. In recent years, it has also been found that shear is a problem with centrifugal pumps, eby frustrated - SteamStuff
Re: Value in v configuration over flat opposed? - 7 weeks ago
This partly depends on whether you are using single or double acting cylinders. A vee configuration is great for a double acting two cylinder since you can put each cylinder on just one crankpin -- reducing crank weight, improving stiffness, and simplifying construction. You also get a benefit in that the primary unbalance forces resolve into a rotating force that can be cancelled with a crankshby frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - 2 months ago
Here is one of a handful of engines which I think utilizes the theoretically optimum piston for single-acting steam engines. You will see that the piston is dumb bell-shaped, with rings on each end. This is advantageous in the following circumstances: High pressure Low RPM Long cutoff In each of the above conditions, a piston will experience increasing steam blowby with the worst case scby frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - 2 months ago
Maybe the best way to approach alloy pistons is to use the same cylinder bore diameter as in an IC engine using the same sized piston.by frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - 2 months ago
Hi Rolly, That's a gorgeous model. Building scale models always seems like a tradeoff. The bigger model is easier to examine and can be more readily handled without fear of breakage. The smaller model is a joy simply because it exists at that scale -- anyone who works in metal appreciates the craftsmanship involved. Regards, Kenby frustrated - SteamStuff
Re: Thomson Surrey - 2 months ago
Hi Chris, My sincerest thanks for the photos -- I had pretty much given up hope of finding a good depiction of a GE vehicle. My e-mail is: kenatgm@aol.com Warmest Regards, Kenby frustrated - SteamStuff
Flash Steam hydroplane - 2 months ago
Hi Anybody: I received some photos that look just like one of the tether boats illustrated in that "Flash Steam" booklet. It appears the builders were a little off on the scale and neglected to fit a tether. Does anyone know anything about this boat? Regards, Kenby frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - 2 months ago
Hi Rolly, That is a beautiful engine. It's too bad that he didn't listen regarding the valves. An automotive-style poppet would have virtually no leakage, if fitted properly. Being a scale model, he didn't need to have a valve in proportion to the engine. As far as valves go, the square-cube rule works in their favor since the volume that needs to be filled decreases much more rapidly thanby frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - 2 months ago
This design seems to need an interstage receiver between the HP and LP pistons. If the HP piston is single-acting, it can only deliver steam to the LP stage once per revolution. A double-acting LP stage needs to accept steam twice per revolution. Since the HP can only feed the LP half of the time, a receiver is necessary to ensure a smooth and steady delivery to the LP cylinder. Such a receiverby frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - 2 months ago
I was just looking up the requirements to license an "Assembled Vehicle" in the state of Michigan (see new discussion topic). For an automobile, it clearly states that the car must have differential gear. It would seem to be a good idea to find out is that is a requirement in your area. Regards, Kenby frustrated - SteamStuff
Re: Assembled Vehicles - 2 months ago
I was able to download the vehicle inspection form. It's less stringent than I feared.by frustrated - SteamStuff
Assembled Vehicles - 2 months ago
It occurs to me that we almost never hear anyone talk about what it takes to build a vehicle and place it on the road. So, I did a little research and found the Michigan rules for "Assembled Vehicles" (attached). Some of this makes me wonder -- if you build the engine, how do you deal with questions like proof of ownership, cost, and so on? I filled out an information request form onlby frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - 2 months ago
OK, lots of stuff here to address. Let's start with the really easy one -- compound engines apparently have no efficiency advantage over uniflow expanders. Marks Standard Handbook for Mechanical Engineers, 1923 edition, gives efficiencies for various steam engines. As noted, "These unjacketed simple engines are thus about equal in economy to our best compounds. Tests on 100-h.p. condensinby frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - 2 months ago
I agree with Rolly, I worked with turbines onboard ship. The main propulsion turbines were quite efficient, but they were also large as they each produced 70,000 shp. The standby lubeoil pump, main circ water pump, and steam driven fire pumps were sort of wasteful but had the advantage of being independent of electrical supplies -- which is an important consideration on a warship where you mightby frustrated - SteamStuff
Re: Thomson Surrey - 2 months ago
Hi Chris, I would have responded to your post earlier but I was out in an area without cell coverage during the holiday weekend. The original reason for asking about the Thomson machine is that I have been writing a book on General Electric steam cars for Tom Kimmel to accompany other books such as the Yuba steam tractor, Baker, Scott-Newcomb, Winslow, Brooks, Delling and other makes. Thereby frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - 2 months ago
William, As I said, Tom has the Gary Hadden engines. These have nothing to do with steam busses. They are a double acting, poppet valve, uniflow steam engine designed by SACA member Gary Hadden for steam buggies, boats, and so on. I don't think he realized that he was essentially duplicating the Scott-Newcomb engine, minus aux. exhaust valve, but he did. ALL steam engines have heat losses,by frustrated - SteamStuff
Re: Uniflow steamengine at 20% efficiency in a car project - 2 months ago
If you are looking to build a double acting, uniflow steam engine, I would suggest visiting Tom Kimmel. He has a few of the Gary Hadden engines, along with the patterns. Gary's engines have sliding camshafts for variable cutoffs and very closely resemble the Scott-Newcomb steam engine, except that had an auxiliary exhaust valve and was semi-uniflow. Achieving 20 percent efficiency in a steam cby frustrated - SteamStuff
Re: start up times - 2 months ago
Actually, steam plants can change speed quite readily. Central power stations are designed to run at a fairly constant output, but that's hardly the only kind of steam plant out there. Consider an aircraft carrier. Maybe not as big as a central generating plant, but it still packs 280,000 horses in the main engines along with 64 megawatts of electrical generating capacity, along with providing hby frustrated - SteamStuff
Re: start up times - 2 months ago
I'm honestly puzzled by the heat transfer fluid surrounding a tank of water. While I can think of some effective binary fluid systems, and some systems with water heated by water, none of them seem to fit the bill. In any case, producing steam without later adding more heat to raise the steam temperature well into the superheat region will not allow the builder to fabricate an engine capable of aby frustrated - SteamStuff
Re: Chicagoland Mini Meet - 2 months ago
I added a few videos of the mini-meet to the club Facebook page. Oscillating Engine Tom Kimmel on Tangeman Steam Tractor Rick Weber Steam Trikeby frustrated - SteamStuff