alt.energy.renewable

On Feb 15, 12:53=A0pm, Dan Bloomquist wrote:
> bsr3...@my-deja.com wrote:
> > On Feb 14, 1:43 am, Dan Bloomquist wrote:
> >> bsr3...@my-deja.com wrote:
> >>> If you are going to be a critic try reading the artical first. =A0They=

> >>> are working with a delta of 120 and could get by with 100 according to=

> >>> the manufacturer of the equipment. =A0It doesn't need to be "really co=
ld
> >>> outside" since they have 1500 gpm of cold water. =A0It clearly said th=
at
> >>> after running through the power plant the hot water was used for
> >>> heating buildings before being injected back into the ground.
> >> I don't get it. You claim a delta T of 120, that means the sink is 165 =
-
> >> 120, or a net heating of 45f. Is this the back end of oil heating?
> >> Sounds pretty dumb as to lead to so much infrastructure. Please provide=

> >> a cite. I have already said that this is a unique situation in the
> >> world. How is your reading comprehension?
>
> > I included this linkhttp://www.yourownpower.com/Power/=A0in my first
> > post to this thread. =A0You included it in a response to me. =A0Did you =
by
> > any chance go to it and read? =A0It answers all the questions you are
> > asking. =A0If you want specifics about tempertures and flow rates look
> > here
>
> >http://www.yourownpower.com/Power/2007GRCPaper.pdf
>
> No where in that paper do they make it clear that they will both sink at
> a very low tempreture _and_ use that sink for domestic heating.
>

Correct, they don't say that, because it would be a stupid thing to
try. They use the hot water after it has passed through the heat
exchanger for domestic heating. From page 3,

"Heat source: Tin =3D 164 =B0F Tout =3D 135 =B0F Flow rate: 530 gpm
Heat sink: Tin =3D 40 =B0F Tout =3D 49 =B0F Flow rate: 1614 gpm"


And from page 5,

"Unfortunately, the injection well is located only 500 ft upstream of
the shallow district heating supply well, and temperature declines
have been observed in this hole. As a result, the district heating
well will be abandoned in 2007 and the heating system subsequently
supplied directly by the discharged fluid from the power plant in
combination with low volumes of hotter waters from the main hot water
supply line for the power plant."

>
> > =A0The site is not as unique as you make it sound. There are plenty of
> > similar areas along the west coast. =A0And looking at this map
>
> >http://www1.eere.energy.gov/geothermal/geomap.html
>
> 3 kilomters!? The Chena thing works because they _don't_ have to pump
> much of a head.

The rest of the sentence is still there. Did you read it? I don't
have a map giving the temperture at 200 feet. But we can see from
this map there are large areas where the temp is ~400=BAF at 9,000 to
10,000 feet. When you compare that to the statement you snipped,

"In the case of Chena Hot Springs, it appears the water is
circulating
to a depth of approximately 3000-5000ft and reaching a maximum
temperature of 250=BAF."

you can see there are probably a lot of places where you could get
180=BAF at ~200 feet.

> > I would say there are probably a lot of places where you could get
> > temps of 180F or so without drilling to deep. =A0According to the first
> > link,
>
> I lived in Northern Ca on a piece of property with hot springs. Fun for
> bathing and heating a couple of houses. Hardly 'a lot' compared to the
> demand for electricity in Ca.
>

By the looks of the map there is more heat further south. And yes,
you need to drill wells. There may be enough there to provide all the
power needed, or not. We would know a lot better if a larger project
than the one at Chena was tried. It certainly looks like it could
come in cheaper than wind or solar, and unlike them it works 24/7.

>
> > "In the case of Chena Hot Springs, it appears the water is circulating
> > to a depth of approximately 3000-5000ft and reaching a maximum
> > temperature of 250=BAF."
>
> >>> Prooving that they could work with a delta of 120 has opened up a lot
> >>> more potential sites then would have been possible using conventional
> >>> equipment.
> >> Proofing what? Please provide an explicit link. I'm listening...
>
> > Prooving that you don't need hot spots that can produce super heated
> > steam to produce power, and that relativly cheap AC equipment can be
> > used.
>
> They had water they didn't have to pump, and lots of it, free piping
> they scavenged. 400kw is not a lot of electricity from 1500gpm.
>

So what, you're saying they should have done a hydro project? 1500gpm
may sound like a lot, but that was only enough for one of the two
units. That's why they went to air cooling for the second unit.
Turns out it worked so well that they are retrofitting the first unit
with air cooling for winter use as well.

>
> > Fromhttp://www.yourownpower.com/Power/grc%20paper.pdf
>
> > "4. The cost advantage of HVAC equipment over power generation
> > equipment allows an economically viable product despite the inherently
> > (=3D second law of thermodynamics) low thermal efficiency of low
> > temperature waste heat power recovery."
>
> Wow. They plan to use an air conditioning compressor in reverse? I guess
> if they get away with it. But:

UTC isn't some little fly by night outfit. They designed the
compressor and they are willing to stand behind it. Ever look at a
turbocharger? The exhaust turbine and the intake compressor have the
same shape. In the exhaust turbine you have gas under pressure
entering at the edge and leaving at the center to produce power. You
use that power to run the compressor at the other end of the same
shaft. In the compressor the air enters at the center and leaves
under pressure at the edge.

> "This temperature is in general too low for ORC duty. However, given the
> year-round availability of 3 0C (37 0F) river water ORC-operation with
> an 8% thermal efficiency is possible."
>
> So, where is the domestic heating from the sink?

Only in your mind.

> > There are also a lot of places where there is waste heat that could be
> > utilized. =A0Some examples are even shown here
>
> >http://www.yourownpower.com/Power/grc%20paper.pdf
>
> > "4. EXISTING INSTALLATIONS
> > Three 200 kW power producing installations using different waste heat
> > sources have been in operation since January 2004. The exhaust heat of
> > an Pratt and Whitney FT12 gas turbine is used as heat input source for
> > the organic Rankine cycle in East-Hartford, CT.
>
> There is nothing new here. Combined cycle plants have been around for a
> long time.
>
> > A second installation
> > uses the heat from a landfill flare in Austin, TX while the exhaust
> > heat from three Jenbacher reciprocating engines powers the third
> > installation in Danville, IL. Figure 5 shows pictures of
> > these installations."
>
> Huh? you have a gas flare and call that low grade heat? How does that
> make sense? And once again, there is nothing new about combined cycle.
> That someone is using diesel to produce electricity in the first place
> is very dumb.

There's your reading problem again. The quote says "waste heat" not
"low grade heat" The two systems using exhaust are using low grade
heat. I didn't feel a need to edit out the part about the gas flare.
And they didn't say the primary task of either of those engines was to
produce electricity.

> > All of the above used air cooling.
>
> > "5. LOWER TEMPERATURE ORC APPLICATIONS
> > Cost-effective ORC operation requires a minimum temperature difference
> > between evaporator and condenser saturation temperatures of about 50K
> > or 100F"
>
> And again. You need an enormous amount of heat the likes of one unusual
> =A0 Chena Hot Springs.

Or the many other hot springs they have in Alaska or California or
many of the other western states. I tend to think Chena is not all
that ideal a sight. I doubt they would have started the project if
they had access to the grid.

> >>> =A0And the equipment used is less expensive than the
> >>> traditional equipment to boot. =A0I would say they've got something to=

> >>> feel good about.
> >> Equipment scales to delta T. At least from what I know. If I am wrong,
> >> please provide your cite...- Hide quoted text -
>
> > Mass produced AC equipment is less expensive than specialized high
> > temp/pressure power equipment.
>
> Yea, I see these guys claiming $5/watt and they had the heat. They don't
> say what it would cost if they had not scavenged pipe and who knows how
> much labor. Much less develop sources of heat if they didn't just have it.=


You think those drilled wells were natural formations? If you went
looking for a site rather than working with what you have you might
not have to run 3000 feet of pipe here and 2700 feet of pipe there.

> >http://www.yourownpower.com/Power/grc%20paper.pdf
>
> You have already posted that link.- Hide quoted text -

You asked me to provide a cite so I gave it. Which do you think is
going to be more expensive, equipment made to withstand high
tempretures and pressures or low tempertures and pressures? Equipment
that is made in small lots for power companies or mass produced along
with common AC equipment? Does it really matter if the equipment is a
bit bigger if it doesn't cost any more?

> - Show quoted text -