On 31-Mar-2004, "Roland Paterson-Jones" wrote:

Mmm, hot water delivered is 114F, that's 45C, hardly luke-warm!

We have to take the rest of the measurements with a pinch of salt then.

As you know, heat loss is proportional to the temperature delta. How about a
realistic scenario.

OK, let's bump the temperature up to 125F. That's a temperature differential
of 64F.

That means the heat loss and cost increases by a factor of 64/51.

The average heat loss cost at 114F is $4/month, so at 125F it will be $5.02.
(4*64/51)

But, of course, don't forget that many people keep their water heaters in areas
that are warmer than 61F, so the temperature differential may be lower than
mine.

The main issue with electric water heaters, as far as I'm concerned, is that
the Carnot-limited power source wastes at least 60% of the fuel source heat
to the local rivers and dams, for you to take the (optimistic) 40% and
convert it back to heat.

I have absolutely no control over that nor was my study directed at that issue.

Your case study is flawed, and you lack appreciation of the big picture.

I never claimed to be presenting either a study or a solution to the "big
picture" of energy usage. My study was simply to measure the actual heat loss
energy for one water heater in a known environment. As shown above, you can
adapt the figures to other situations.

On Thu, 1 Apr 2004 01:04:20 GMT, "Phil Sherrod"
wrote:


The main issue with electric water heaters, as far as I'm concerned, is that
the Carnot-limited power source wastes at least 60% of the fuel source heat
to the local rivers and dams, for you to take the (optimistic) 40% and
convert it back to heat.

I have absolutely no control over that nor was my study directed at that issue.

Your case study is flawed, and you lack appreciation of the big picture.

I never claimed to be presenting either a study or a solution to the "big
picture" of energy usage. My study was simply to measure the actual heat loss
energy for one water heater in a known environment. As shown above, you can
adapt the figures to other situations.

Phil,

Just ignore Roland. He just likes to hear himself type and throw out fancy
terms. Doesn't have a clue. Your measurements were right on target. Even
the temperature selected. The water heater I recently installed in one of my
cabins came from the Home Depot with the 'stats set at 115 deg F. Probably
the lawyers at work again. I bet just about nobody changes that setting.

Even Roland's appreciation of the "big picture" is incorrect. Modern
supercritcal fossil plants achieve overall efficiencies in the 50% range.
Even the good old nuke are in the high 30s. The Sequoyah Nuclear Plant where
I worked for about 10 years recently replaced the steam generators. The
improved design plus some plant upgrades pushed the efficiency to 38% and a
fraction, something that spawned a small staff party. Oh, and BTW, Roland,
the waste heat goes up the cooling tower stacks and not into the lake, at
least not to any significant extent. Much to the chagrin of local fishermen
who discovered that the warm water (pre-cooling towers) spawned great fish
growth and fishing conditions.

John



---
John De Armond

http://bellsouthpwp.net/j/o/johngd/
Cleveland, Occupied TN

On 31-Mar-2004, Neon John wrote:

Just ignore Roland. He just likes to hear himself type and throw out fancy
terms. Doesn't have a clue. Your measurements were right on target. Even
the temperature selected. The water heater I recently installed in one of my
cabins came from the Home Depot with the 'stats set at 115 deg F. Probably
the lawyers at work again. I bet just about nobody changes that setting.

Even Roland's appreciation of the "big picture" is incorrect.

Yes, Roland's "big picture" is incorrect. The problem with European
environmentalists like him is that they are cultural imperialists: They want to
impose their standard of living, cars, energy generation, insulation, house
sizes, lighting and room temperatures on all other cultures. They even have
standards for family size. I could care less whether he rides a bicycle or
drives a Mercedes, but it really bothers him that I drive a SUV and have 200
watts of light in my office. But what's worse is that if he had the
opportunity, he would impose his political/environmental/social policy on the
whole world. "Liberals" are only tolerant of other liberals; they are dogmatic
and unwilling to accept those who prefer different lifestyles.

In article ,
Neon John wrote:

Even Roland's appreciation of the "big picture" is incorrect. Modern
supercritcal fossil plants achieve overall efficiencies in the 50% range.
Even the good old nuke are in the high 30s. The Sequoyah Nuclear Plant where
I worked for about 10 years recently replaced the steam generators. The
improved design plus some plant upgrades pushed the efficiency to 38% and a
fraction, something that spawned a small staff party. Oh, and BTW, Roland,
the waste heat goes up the cooling tower stacks and not into the lake, at
least not to any significant extent. Much to the chagrin of local fishermen
who discovered that the warm water (pre-cooling towers) spawned great fish
growth and fishing conditions.
John De Armond

Depending on *how* it's measured, efficiency can be higher. Back in '70,
I worked as a co-op at the Eddystone plant (Philly area), then arguably
the most efficient plant in the world -- only the USSR supposedly had a
better one. Steam started at 4,999.5 psi according the gauge, ended in
partial vacuum. They burned (actually closer to exploded) 1-200 tons of
coal an hour and we STILL needed heaters in the "basement" labs in the
winter. [yes, we had walls ;-)] They only used the gas turbines (jet
engines) in the yard when absolutely necessary, because their efficiency
was so low.

By each measure, efficiency was pretty high.

But are they making plants like that any more? When they built units 3 &
4, they went back to a "mere" 1-2000 psi. AFAIK, only one supercritical
production nuke was built: Peachbottom.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

"Jere Lull" wrote in message
...
In article ,
Neon John wrote:

Even Roland's appreciation of the "big picture" is incorrect. Modern
supercritcal fossil plants achieve overall efficiencies in the 50%
range.
Even the good old nuke are in the high 30s. The Sequoyah Nuclear Plant
where
I worked for about 10 years recently replaced the steam generators. The
improved design plus some plant upgrades pushed the efficiency to 38%
and a
fraction, something that spawned a small staff party. Oh, and BTW,
Roland,
the waste heat goes up the cooling tower stacks and not into the lake,
at
least not to any significant extent. Much to the chagrin of local
fishermen
who discovered that the warm water (pre-cooling towers) spawned great
fish
growth and fishing conditions.
John De Armond

Depending on *how* it's measured, efficiency can be higher. Back in '70,
I worked as a co-op at the Eddystone plant (Philly area), then arguably
the most efficient plant in the world -- only the USSR supposedly had a
better one. Steam started at 4,999.5 psi according the gauge, ended in
partial vacuum. They burned (actually closer to exploded) 1-200 tons of
coal an hour and we STILL needed heaters in the "basement" labs in the
winter. [yes, we had walls ;-)] They only used the gas turbines (jet
engines) in the yard when absolutely necessary, because their efficiency
was so low.

By each measure, efficiency was pretty high.

But are they making plants like that any more? When they built units 3 &
4, they went back to a "mere" 1-2000 psi. AFAIK, only one supercritical
production nuke was built: Peachbottom.

Indian Point I (long shutdown now) was a nuke that used the reactor to make
saturated steam, then used an oil-fired superheater to superheat the steam.
Not sure how hot it ran, but pressure was only about 1000 psi (due to the
limits of the nuke's steam-generator).

In recent past, the industry has been going for combined-cycle gas-turbine.
Less pollution controls needed and overall cycle efficiencies running close
to 60%. But this has raised demand on natural gas, so that price has
started to climb and things are shifting once again.

daestrom

Indian Point was an efficiency disaster from the start-up. Probably
due to the inability of the main turbine condensers from operating down
to 1" hg. absolute. No one ever found out why the plants thermo
cycle was so way 'out of whack'. Suggestions were posed but never
proved that the condensation on the condenser tubes was not film-wise
condensation but some sort of 'wierd' drop-wise or mixture condensation
..... and no one ever found out why.

In article , daestrom
wrote:

"Jere Lull" wrote in message
...
In article ,
Neon John wrote:

Even Roland's appreciation of the "big picture" is incorrect. Modern
supercritcal fossil plants achieve overall efficiencies in the 50%
range.
Even the good old nuke are in the high 30s. The Sequoyah Nuclear Plant
where
I worked for about 10 years recently replaced the steam generators. The
improved design plus some plant upgrades pushed the efficiency to 38%
and a
fraction, something that spawned a small staff party. Oh, and BTW,
Roland,
the waste heat goes up the cooling tower stacks and not into the lake,
at
least not to any significant extent. Much to the chagrin of local
fishermen
who discovered that the warm water (pre-cooling towers) spawned great
fish
growth and fishing conditions.
John De Armond

Depending on *how* it's measured, efficiency can be higher. Back in '70,
I worked as a co-op at the Eddystone plant (Philly area), then arguably
the most efficient plant in the world -- only the USSR supposedly had a
better one. Steam started at 4,999.5 psi according the gauge, ended in
partial vacuum. They burned (actually closer to exploded) 1-200 tons of
coal an hour and we STILL needed heaters in the "basement" labs in the
winter. [yes, we had walls ;-)] They only used the gas turbines (jet
engines) in the yard when absolutely necessary, because their efficiency
was so low.

By each measure, efficiency was pretty high.

But are they making plants like that any more? When they built units 3 &
4, they went back to a "mere" 1-2000 psi. AFAIK, only one supercritical
production nuke was built: Peachbottom.

Indian Point I (long shutdown now) was a nuke that used the reactor to make
saturated steam, then used an oil-fired superheater to superheat the steam.
Not sure how hot it ran, but pressure was only about 1000 psi (due to the
limits of the nuke's steam-generator).

In recent past, the industry has been going for combined-cycle gas-turbine.
Less pollution controls needed and overall cycle efficiencies running close
to 60%. But this has raised demand on natural gas, so that price has
started to climb and things are shifting once again.

daestrom

"Rich Hampel" wrote in message
...
Indian Point was an efficiency disaster from the start-up. Probably
due to the inability of the main turbine condensers from operating down
to 1" hg. absolute. No one ever found out why the plants thermo
cycle was so way 'out of whack'. Suggestions were posed but never
proved that the condensation on the condenser tubes was not film-wise
condensation but some sort of 'wierd' drop-wise or mixture condensation
.... and no one ever found out why.

Actually, what you suggest might be backwards. 'drop-wise' condensation is
a much better heat-transfer mechanism than film. The two major performance
issues on the steam side of condensers is the thickness of the film through
which heat must be transferred in order to get to the metal tube, and the
amount of non-condensibles that accumulate against the film surface (even
trace amounts develop a film through which the vapor must diffuse to reach
the film). I have a good book at work ("Heat-Transfer", can't recall the
author/publisher from here) that has a couple of good chapters on condensing
mechanisms. Although somewhat dated (circa ~1990), it discusses that the
'Holy Grail' of condenser performance is to develop surfaces for promoting
stable 'drop-wise' condensation. No film against tube surface means heat
transfer coefficients can be on the order of 3X to 8X better. The
non-condensables problem has been well managed for many years with 'dry
suction pipes' and other design features.

I know IP One has been shutdown for a long time, didn't know it had an
abysmal performance problem. Just pointed out that it had a unique
combination of nuc and fossil fuels. It might be interesting to pour over
the old operating logs/data and apply the modern tools of station thermo
performance to see where things were NQR (not quite right). Of course, some
engineer may have found the problem back then, but the cost of fixing it
after the plant was already built may have been prohibitive.

If the design had hoped to achieve drop-wise condensation in the condenser
(by using some special treatment on the tube surface) but was not able to,
that would have required reverting back to a larger, film-wise surface
condenser. The cost of putting in a larger condenser and ripping apart the
turbine deck and all to do so would probably be reason enough to lock the
door and walk away.

daestrom

"Rich Hampel" wrote in message
...
Indian Point was an efficiency disaster from the start-up. Probably
due to the inability of the main turbine condensers from operating down
to 1" hg. absolute. No one ever found out why the plants thermo
cycle was so way 'out of whack'. Suggestions were posed but never
proved that the condensation on the condenser tubes was not film-wise
condensation but some sort of 'wierd' drop-wise or mixture condensation
.... and no one ever found out why.

Actually, what you suggest might be backwards. 'drop-wise' condensation is
a much better heat-transfer mechanism than film. The two major performance
issues on the steam side of condensers is the thickness of the film through
which heat must be transferred in order to get to the metal tube, and the
amount of non-condensibles that accumulate against the film surface (even
trace amounts develop a film through which the vapor must diffuse to reach
the film). I have a good book at work ("Heat-Transfer", can't recall the
author/publisher from here) that has a couple of good chapters on condensing
mechanisms. Although somewhat dated (circa ~1990), it discusses that the
'Holy Grail' of condenser performance is to develop surfaces for promoting
stable 'drop-wise' condensation. No film against tube surface means heat
transfer coefficients can be on the order of 3X to 8X better. The
non-condensables problem has been well managed for many years with 'dry
suction pipes' and other design features.

I know IP One has been shutdown for a long time, didn't know it had an
abysmal performance problem. Just pointed out that it had a unique
combination of nuc and fossil fuels. It might be interesting to pour over
the old operating logs/data and apply the modern tools of station thermo
performance to see where things were NQR (not quite right). Of course, some
engineer may have found the problem back then, but the cost of fixing it
after the plant was already built may have been prohibitive.

If the design had hoped to achieve drop-wise condensation in the condenser
(by using some special treatment on the tube surface) but was not able to,
that would have required reverting back to a larger, film-wise surface
condenser. The cost of putting in a larger condenser and ripping apart the
turbine deck and all to do so would probably be reason enough to lock the
door and walk away.

daestrom

Indian Point was an efficiency disaster from the start-up. Probably
due to the inability of the main turbine condensers from operating down
to 1" hg. absolute. No one ever found out why the plants thermo
cycle was so way 'out of whack'. Suggestions were posed but never
proved that the condensation on the condenser tubes was not film-wise
condensation but some sort of 'wierd' drop-wise or mixture condensation
..... and no one ever found out why.

In article , daestrom
wrote:

"Jere Lull" wrote in message
...
In article ,
Neon John wrote:

Even Roland's appreciation of the "big picture" is incorrect. Modern
supercritcal fossil plants achieve overall efficiencies in the 50%
range.
Even the good old nuke are in the high 30s. The Sequoyah Nuclear Plant
where
I worked for about 10 years recently replaced the steam generators. The
improved design plus some plant upgrades pushed the efficiency to 38%
and a
fraction, something that spawned a small staff party. Oh, and BTW,
Roland,
the waste heat goes up the cooling tower stacks and not into the lake,
at
least not to any significant extent. Much to the chagrin of local
fishermen
who discovered that the warm water (pre-cooling towers) spawned great
fish
growth and fishing conditions.
John De Armond

Depending on *how* it's measured, efficiency can be higher. Back in '70,
I worked as a co-op at the Eddystone plant (Philly area), then arguably
the most efficient plant in the world -- only the USSR supposedly had a
better one. Steam started at 4,999.5 psi according the gauge, ended in
partial vacuum. They burned (actually closer to exploded) 1-200 tons of
coal an hour and we STILL needed heaters in the "basement" labs in the
winter. [yes, we had walls ;-)] They only used the gas turbines (jet
engines) in the yard when absolutely necessary, because their efficiency
was so low.

By each measure, efficiency was pretty high.

But are they making plants like that any more? When they built units 3 &
4, they went back to a "mere" 1-2000 psi. AFAIK, only one supercritical
production nuke was built: Peachbottom.

Indian Point I (long shutdown now) was a nuke that used the reactor to make
saturated steam, then used an oil-fired superheater to superheat the steam.
Not sure how hot it ran, but pressure was only about 1000 psi (due to the
limits of the nuke's steam-generator).

In recent past, the industry has been going for combined-cycle gas-turbine.
Less pollution controls needed and overall cycle efficiencies running close
to 60%. But this has raised demand on natural gas, so that price has
started to climb and things are shifting once again.

daestrom

"Jere Lull" wrote in message
...
In article ,
Neon John wrote:

Even Roland's appreciation of the "big picture" is incorrect. Modern
supercritcal fossil plants achieve overall efficiencies in the 50%
range.
Even the good old nuke are in the high 30s. The Sequoyah Nuclear Plant
where
I worked for about 10 years recently replaced the steam generators. The
improved design plus some plant upgrades pushed the efficiency to 38%
and a
fraction, something that spawned a small staff party. Oh, and BTW,
Roland,
the waste heat goes up the cooling tower stacks and not into the lake,
at
least not to any significant extent. Much to the chagrin of local
fishermen
who discovered that the warm water (pre-cooling towers) spawned great
fish
growth and fishing conditions.
John De Armond

Depending on *how* it's measured, efficiency can be higher. Back in '70,
I worked as a co-op at the Eddystone plant (Philly area), then arguably
the most efficient plant in the world -- only the USSR supposedly had a
better one. Steam started at 4,999.5 psi according the gauge, ended in
partial vacuum. They burned (actually closer to exploded) 1-200 tons of
coal an hour and we STILL needed heaters in the "basement" labs in the
winter. [yes, we had walls ;-)] They only used the gas turbines (jet
engines) in the yard when absolutely necessary, because their efficiency
was so low.

By each measure, efficiency was pretty high.

But are they making plants like that any more? When they built units 3 &
4, they went back to a "mere" 1-2000 psi. AFAIK, only one supercritical
production nuke was built: Peachbottom.

Indian Point I (long shutdown now) was a nuke that used the reactor to make
saturated steam, then used an oil-fired superheater to superheat the steam.
Not sure how hot it ran, but pressure was only about 1000 psi (due to the
limits of the nuke's steam-generator).

In recent past, the industry has been going for combined-cycle gas-turbine.
Less pollution controls needed and overall cycle efficiencies running close
to 60%. But this has raised demand on natural gas, so that price has
started to climb and things are shifting once again.

daestrom