On Nov 6, 2009, at 10:06 PM, [email protected] wrote:
In reply to Terry Blanton's message of Tue, 3 Nov 2009 13:19:16
-0500:
Hi,
[snip]
Solar trough developers prefer to use so-called wet cooling in which
water must be constantly be replenished to make up for evaporation.
Regulators, meanwhile, are pushing developers to use dry cooling,
which takes about 90 percent less water but is more expensive and
reduces the efficiency –- and profitability – of a power plant.
[snip]
I would suggest they use wet cooling....with salt water. As a
byproduct they
would produce fresh water.
This is a great application for the solar tower concept - which is
only about 1% efficient anyway. Instead of using the great chimney
tower for energy, use it as a vapor condensing tower, and use some of
the huge territory on the outer sides for solar cells. In northern
latitudes mounting solar cells on vertical surfaces can be better
than on horizontal surfaces, and they can be moved around a
cylindrical tower surface in order to follow the sun. A great
chimney tower could be used as a community cooling resource, for
solar thermal, nuclear, and conventional thermal power plants.
A great condensing chimney could be even be operated as a closed
system, with an insulated inside tower to carry the warm column much
of the way up the chimney by buoyancy, and then above and downward
around the insulated inner chimney the air flow enters the cool high
altitude condensing part of the chimney, with negative buoyancy
driving the cool dry air downward. The outside condensing skin could
be thin and corrugated to maximize heat exchange, with the structural
support primarily provided by the inner tower. The h*g potential
energy of the water condensed at high altitude could be utilized by
channeling it into pipes in order to drive turbine generators at the
base of the tower, to collect some of the buoyancy energy of the
column, and drive the column flow through use of fans directly
coupled to the water turbines. This would compensate for the added
mass the water vapor adds to the upward column. This might work
especially well at night, when Carnot cycle heat engines would be
used to collect thermal energy stored during the day by melting salt
in underground silos. This kind of closed system should be many times
more efficient than a conventional solar chimney, and be able to
operate with much less height. Electric motors could be coupled to
the fans to initiate the tower air flow, and to generate power from
the air flow if it becomes too fast. This kind of tower might also
serve as a mounting structure for windmills in appropriate locations.
Best regards,
Horace Heffner
http://www.mtaonline.net/~hheffner/
