Re: Solar breakthrough - when?

From: Tkalbfus1 (tkalbfus1_at_aol.com)
Date: 08/19/04 

Date: 19 Aug 2004 23:42:09 GMT

Fred B. McGalliard said,
>The killer here is that you need both a large turbine and a very large heat
>exchanger (two actually). Very large heat exchangers sitting in salt water
>tend to become reefs.

The turbines don't come in contact with salt water though, the come in contact
with ammonia vapor, not water. As for the heat exchangers, you need something
that conducts heat efficiently but repells or provides no purchase for the
organisms that make up reefs. At great depths, I do not believe the reefs would
grow. At lesser depths the reefs would tend to be at the same temperature as
the sea water. Of course the heat exchangers would tend to draw warmth from the
ocean because of the cold liquid ammonia flowing inside. The coldness of the
heat exchangers would tend to inhibit growth on the heat exchanger's surface.
The heat exchangers will either try to draw warmth from the upper ocean water
or from the organisms that try to grow on its surface. I believe reefs prefer
warm conditions in which to grow, I do not belief it would enjoy attaching to a
near freezing surface. Perhaps the portion of the heat exchangers where growth
is possible could be covered with a substance where growth is not possible.

>Of course it will help to have the hot water start out closer to
>100C than to 30C, and this should make the collector less prone to fouling.
>I think this is not going to be solved with 1940s vintage engineering.
>

Well there are hydrothermal vents, in a very short distance you have near
boiling water very close to near freezing water. A heat exchanger would work
very well here, and with this energy source you could use water electrolysis to
fill a pipe at this great depth. The hydrogen in the pipe is already compressed
and a narrower pipe can carry a great deal of hydrogen compared to a surface
pipeline. The pipeline can be made very cheaply and would not have to be strong
as it would be the water pressure at the ocean bottom which holds the hydrogen
in the pipes. And more expensive piping with thicker walls could contain the
hydrogen when the pipe inclines steeply up to a surface terminal near a
populated area for hydrogen delivery. Everytime the valve is opened the
hydrogen would flow outward toward the open valve due to this great pressure.
Hydrogen could then be delivered to people's homes in the same manner as
methane.

Tom

Relevant Pages

  • Re: Solar breakthrough - when?
    ... I do not believe the reefs would grow. ... > to avoid most marine fouling, and one at the surface, making it a potential ... > alternatives that do not fit in our normal idea of heat exchangers. ... I suspect barnacles are fairly decent insulators. ...
    (sci.energy.hydrogen)
  • Re: Solar breakthrough - when?
    ... I do not believe the reefs would grow. ... to avoid most marine fouling, and one at the surface, making it a potential ... alternatives that do not fit in our normal idea of heat exchangers. ...
    (sci.energy.hydrogen)