Here's the probably 80% + efficient boiler that runs on H2 and O2 as it's fuel and oxidizer.

    This concept for a boiler design using H2 as it's fuel source and O2 as it's oxidizer is the ONLY feasible way to use this fuel to it's maximum efficiency. The first crucial concept to look at is that this boiler, unlike any other, does not use the heat produced by the combustion of fuel to heat water into steam in a separate container. This is because the combustion of the reactants creates superheated steam as it's only by-product. Therefore the combustion of said reactants will take place INSIDE the boiler chamber itself. Not outside it or beneath it like on Grandma's old cook stove.

    Oh boy, that one little thing changes everything in figuring the efficiency for a steam driven electrical generating system doesn't it? Imagine that, ZERO losses of heat energy up the chimney! Another immediately obvious advantage is that with this system we won't need to use ANY air. The gasses necessary for complete combustion of the reactants are found naturally in water (8:1 in pounds, by weight) and so if we burn those gasses in that natural ratio (again, by weight) in our
boiler it will result in complete combustion without air being necessary at all.

    Inducted air is not even desirable because it wouldn't allow us to do some of the other things that we can do with it this way. Because of this I guess it could make a nice power source for a ship, submarine or space vehicle.    Since the only by product of this boiler is superheated steam and
since that is what is used to turn the big turbines in most of our commercial electric plants today this just fits right in doesn't it? The major advantage that we have here is the same thing that you get from a dam in hydroelectric power. If we install a valve [(6) on the diagram] on the main steam pipe going to the first turbine then we have the opportunity to restrict the flow of the steam after we first start the system, until we build whatever kind of pressure we want it to work at (say 5000 psi).

    Then we open the valve so that we are delivering superheated steam (5000 degrees + or -) to our turbine at 5000 psi. As long as we control the rate of flow so that we only let as much steam out to the turbine as we are creating by burning our fuel then we can maintain the system in equilibrium

    At the bottom of the boiler you will notice the fuel feeds (2) with the little "spark plug" things on their sides (3) to initially start the system. I designed them to look like the nozzles on an oxyacetylene torch but a better design might be like a rocket motor. We really don't need thrust here though. Just complete combustion.

    The main boiler skin (1) must be able to withstand very high temperatures and pressures. After all H2 with O2 burns at 7,000 degrees and steel melts at 6,000 degrees so we will have to remove quite a bit of our original heat pretty quickly. To do this I show superheaters (9) which will take the
steam that has left the previous turbine, reheat it and turn another turbine. With enough of them we should be able to manage the excess heat. I believe that around 5,000 degrees is the upper limit for today's power generating systems. I think that we could drop it down into that range. Also notice
the little pumps (8) after the turbines. This is to keep back pressure from building up between the turbines.

    One more thing. If you wanted to turn this into a loop system all you would have to do is condense the steam back into water and run it into the seperator/splices. No new electrolyte would be necessary as that will always remain in solution in our seperator/splices.