Raptor75

I was wondering if it would be possible to harness the exhaust heat to drive a stream powered turbo charger. The steam would drive the turbo that the exhaust gas normally would. The steaming fluid may be a different liquid then water at allow a lower boiling temperature. The fact that the Rotary dumps so much heat into the exhaust makes this an ideal set up.

The advantages are obvious, no turbo lag, no exhaust restriction, relative light weight. The down side would be the streamer would have to come up to operating temperature and their would be a question of enough steam power at higher RPMs.

What do you think?

turbine

Dude I thought the same thing. And why not electric turbo?

rotarygod

While in theory I think it could work, it wouldn't be terribly practical. As you said you would need to wait for water to heat up for steam to build up. You'd need a "boiler" where pressure would build up to a set level. Steam train boilers would be as low in pressure as 120 psi and sometimes over 200 psi. You have 2 ways of proceding from here. One way is to bleed off any excess pressure above this point. The problem with this is that you will have to refill the water tank as railroad steam engines had to do. The good thing about this system though is that it is simple and when the turbo was to spool, all you'd have to do is to release a valve which dumps all the steam pressure through to the turbo. Depending on the size of the boiler, you may or may not have adequate pressure to hold boost for very long. The other option would be to design a closed loop steam system such as in nuclear powerplants and warships. Now you add complexity in the form of needing both a hot and cold side for condensing the steam back down.

All in all while the idea could technically be made to work, putting it into use would not be very easy or practical.

turbine

Steam powered engines have unreal power. They stopped using them because coal is bad. The downpipe could be double lined. Run water through it and get your steam. Cool the EGT at the same time. Drop in a couple of deep cycle batteries for electric powered FI.

Raptor75

I to thought of electric but it would be parasitic and the conversion from mechanical energy to electrical then back to mechanical would be very inefficient. Stream would use energy normally wasted. My big concern would be the amount of steam needed at high RPMs and how to drive the steam back to the boiler.

turbine

What you would need is a 20b motor. Use the first two rotors as normal. Keep using the 13b ECU and all others. The third rotor is your steam powered chamber. Seal the plug holes. You would need blow off valves and a control unit for power settings.

Ajax

BMW is already doing it. http://www.gizmag.com/go/4936/

Raptor75

I would think closed loop is the way to go and again a liquid that would boil at lower temperatures then water would help the process boil quicker and recoup quicker. The condensing of the fluid would be tricky to accomplish because of access to cooling air. The steam part of the system would be no more complicated then standard air conditioning units which have proven to be practical. Like any other innovation it would not be easy but few new ideas ever are.

turbine

Run a 5 gallon tank. Charge your system, when you wanted to use it. Kind of like Nitrous is used. If you don't use all the water in the heated chamber, blow it off or return it to the water tank.

turbine

I have been thinking about this for a while. Not saying it would work, but whoever thought a wankle would work.

Raptor75

Interesting, looks like I'm in good company. BMW is using the steam to actually drive the car, I was thinking of just driving a turbo so the complexity and weight go down. Thanks for the link.

rotarygod

The one thing you really need to think about is the pressure in the system. More steam pressure is more energy to use. However the greater the pressure, the higher the boiling point of water or any other liguid. Ethanol evaporates at 180 degrees F at normal "ambient" pressure" and methanol evaporates much lower. You definitely wouldn't want water if you want to heat it up fast and keep the temperatures down. You will need the pressure though.

You would want far more available pressure than what you are planning to use. It's always good to have a reserve and the greater the pressure available, the faster the turbo would start to spin. The trick is going to be in the boost controller.

rotarygod

Well it looks like you aren't the first person to think of this. Here are a couple of forum links to the same topic:
http://www.steamcar.net/phorum/read.php?3,249,page=1
http://www.steamautomobile.com/ForuM/list.php?1

egaribo

super heated steam is the best energy vector and the most convenient when use wood us fuel that is cheap and not contaminant. You need and small boiler, cheap and simple.Water is not problem because is recirculated after condensing.1 MM cal of wood cost US$ 15 and the same quantity of gasoil costo US$ 70. If some has know of use of steam in supercharger I Will be much aprecciated if inform me thank egaribo