On Tue, Sep 27, 2005 at 10:07:14PM +0300, Peter wrote:
> 
> On Mon, 26 Sep 2005, Byron A Jeff wrote:
> 
> >>Only if it works. Anyway it would cost less than half to build, compared
> >>to what a 500 Watt Stirling costs (5000 EUR).
> >>
> >>I have been thinking some more about it. I think that a normal
> >>automotive exhaust manifold could be used as the hot part heat exchanger
> >>somehow. It would mate perfectly with the turbine inlet. That could take
> >>care of the high temp. seal which is a problem anyway.
> >
> >The only problem I see is that an exhaust manifold isn't designed to heat 
> >gas
> >though hot gas goes through it. For this project to work there would need 
> >to
> >be an efficient "air burner" that's the target for the solar collector. A 
> >high
> >temp evaporated tube passing air through it is something along the right 
> >lines.
> >Or using a flat steel plate (18in x 18in x 1in) with tubes drilled through 
> >it.
> 
> I made a drawing and you can see it here (thanks to James for putting it 
> up - I have yet to learn how to use the piclist system):
> 
> http://www.piclist.com/techref/member/plp-actcom-f00/sun-turbo-1.htm

WOW!

One element you are missing is the turbocharger lubrication system. You'll
need an oil pump setup too.

> The manifold is optimised in many ways and perfectly mates with the 
> turbo inlet. I would suggest most of its branches to be capped off with 
> lids, glass wool insulation of 1-2 inches wrapped around it, and an 
> inset tube welded to a holed flange put in. The inset tube would be the 
> blackbody of the sun target, through a hole in the flange that bolts it 
> on the manifold. The air from the compressor would enter through another 
> of the flanges and run between the inside tube and the wall of the 
> manifold to heat up, with several circuits until it would exit towards 
> the turbine. It will pass something like 0.08 m^3/second on the cold 
> side and 2-3 times as much on the hot side.

Can you describe where these items would fit using an example manifold?
Here's a large image here:

http://www.brit.ca/~tboicey/mgparts/pics/exhaust_manifold-1.jpg

> >Any idea of the temp and pressure that the turbine inlet is expecting?
> 
> >Also I gotta ask again: are you sure that steam is out of reach? The 
> >conversion from
> >water to steam will give a huge expansion giving a lot of pressure to 
> >drive the
> >turbine.
> 
> Conversion of water to steam gives not 'a lot' of expansion but exactly 
> as predicted by steam tables. To get out power you have to use high 
> temperature. The characteristics of steam are such that at the same 
> 700-800K where the automotive turbo will work with 2-3bar, steam needs 
> 210+ bar. This means that the boiler, the turbine, and the feed pump 
> must take 210bars continuous.

That's not possible. I understand.

> Nobody I know has the technology to work 
> with 210bar steam in the garage, even if not at 700K. Even 40 bars is 
> too much for most 'home use' equipent. If you feel courageous obtain a 
> scuba tank and use it to power your turbine or generator (very 
> dangerous - you cannot blame me if you get hurt).

I'll pass. The pressure is way too high for any perceived benefit.

> Steam is good to use for a certain range of combustion temperatures 
> where the pressure does not become excessive and where it can do a good 
> job (at low efficiency).
> 
> Power stations that use steam at high temperature have complicated and 
> dangerous installations constantly purifying the water in the circuit, 
> adding chemicals like Hydrazine (poison!) to remove oxygen. Any oxygen 
> in the circuit will instantly convert the innards of the equipment into 
> high quality rust, when combined with steam at 700+K.

Ouch.

So back to the all air installation... why is R a water radiator instead of
another intercooler? Would it not be possible to simply immerse both
intercoolers in a water bath?

Will the generator also be the starter? So you supply electricity to get
the setup going in the morning then extract power once it comes up to speed?
There seems to be great symmetry in that.

BAJ
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