They have it at race tracks. Otherwise you need a tank of it. Know anyone
in the hvac business, they use it to purge refrigerant lines while they
braze. Not really likely to help enouhg to be worth the trouble though.
The other posters are right, bigger wheels are the right solution.

"John Gaquin" wrote in message
...

"Wwj2110" wrote in message

nitrogen helps tires run cooler

How does that work?

JG

Hydrogen is even better yet (better heat transfer coefficient). It is what is
used to cool the 1000 megawatt generators at power plants as air can't carry the
heat from resistance in the windings away fast enough. Just watch out for
flames or sparks. Also hydrogen tends to diffuse through the tire so you have
to replenish it more often.

JJ

On Sun, 26 Oct 2003 00:00:08 GMT, "Lawrence James"
wrote:

They have it at race tracks. Otherwise you need a tank of it. Know anyone
in the hvac business, they use it to purge refrigerant lines while they
braze. Not really likely to help enouhg to be worth the trouble though.
The other posters are right, bigger wheels are the right solution.

"John Gaquin" wrote in message
...

"Wwj2110" wrote in message

nitrogen helps tires run cooler

How does that work?

JG




James Johnson
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On Sun, 02 Nov 2003 00:31:47 +0000, James Johnson wrote:

Hydrogen is even better yet (better heat transfer coefficient). It is what is
used to cool the 1000 megawatt generators at power plants as air can't carry the
heat from resistance in the windings away fast enough. Just watch out for
flames or sparks. Also hydrogen tends to diffuse through the tire so you have
to replenish it more often.


Having worked in a 1000 MW generating station, I can safely say this is
doggie-donuts. I wouldn't have hydrogen (or any explosive gas) within
100ft of a high-power generator!

Lloyd Sumpter

Lloyd Sumpter wrote:

Having worked in a 1000 MW generating station, I can safely say this is
doggie-donuts. I wouldn't have hydrogen (or any explosive gas) within
100ft of a high-power generator!

Hydrogen cooling is pretty common. He isn't, however, thinking about
just where that heat in a tire is supposed to go.

It's not like there is a heat exchanger to remove the heat from the gas
that was heated by the rubber surrounding that gas to begin with.

Rick

On Sun, 02 Nov 2003 19:48:12 GMT, Rick wrote:

Lloyd Sumpter wrote:

Having worked in a 1000 MW generating station, I can safely say this is
doggie-donuts. I wouldn't have hydrogen (or any explosive gas) within
100ft of a high-power generator!

Hydrogen cooling is pretty common. He isn't, however, thinking about
just where that heat in a tire is supposed to go.

It's not like there is a heat exchanger to remove the heat from the gas
that was heated by the rubber surrounding that gas to begin with.

The wheel. I can see how the heat conductive properties of the gas can
make a difference conducting heat from the tire to the wheel at
different rates. Especially since the rubber itself isn't a good heat
conductor.

Steve

Steven Shelikoff wrote:

The wheel.

The area of the wheel exposed to the gas is so small compared to the
area of the tire producing the heat that I doubt it has much of any
practical value in dissipation of heat above and beyond air flow over
and radiation from the tire itself.

Though it doesn't apply much to boat trailer tires, the heat
conductivity of the gas would work against tire cooling in the case of
race cars and aircraft since it would serve to increase the rate of tire
heating in heavy brake application. Many aircraft tire failures are due
to overheated brakes, heating the wheels to the point of causing the
tires to blow out or burn, not from heat generated by the tires themselves.

Rick

On Mon, 03 Nov 2003 00:20:28 GMT, Rick wrote:

Steven Shelikoff wrote:

The wheel.

The area of the wheel exposed to the gas is so small compared to the
area of the tire producing the heat that I doubt it has much of any
practical value in dissipation of heat above and beyond air flow over
and radiation from the tire itself.

Actually, the area of the wheel exposed to the gas in a race car tire is
pretty large compared to the area of the tire since they are wide and
low profile. A narrow, high profile trailer tire doesn't have very much
wheel exposed to the gas for the amount of tire area producing heat.

Though it doesn't apply much to boat trailer tires, the heat
conductivity of the gas would work against tire cooling in the case of
race cars and aircraft since it would serve to increase the rate of tire
heating in heavy brake application. Many aircraft tire failures are due

Of course it all depends on the type of racing. During most racing like
road racing, twisty corners, etc, heavy braking is applied but for very
short durations. Superspeedway racing, not at all. There's plenty of
cooling air ducted to the brakes and the rest of the suspension
components can also act like a heat sink since they are directly
attached to the brakes and wheel. On the other hand, the tires are
always generating heat whenever the car is moving, and especially in
turns. Heat is the enemy of tire life and whatever can be done to take
away more heat from the tire will help. That being said, I sure
wouldn't want hydrogen in my tires.

to overheated brakes, heating the wheels to the point of causing the
tires to blow out or burn, not from heat generated by the tires themselves.

Slowing a 747 from 180 mph to taxi speed is hardly the same thing as
bleeding off 40 or 50 mph from a super light race car. There's a whole
different set of braking requirements, and aircraft brakes are in many
cases under engineered since they depend so much on engine braking to
slow down.

Steve

On Mon, 03 Nov 2003 00:20:28 GMT, Rick wrote:

Steven Shelikoff wrote:

The wheel.

The area of the wheel exposed to the gas is so small compared to the
area of the tire producing the heat that I doubt it has much of any
practical value in dissipation of heat above and beyond air flow over
and radiation from the tire itself.

I agree, the effect of using hydrogen would be minimal, but slightly larger than
using nitrogen. My suggestion to use it was me being a wise a$$.

JJ


Though it doesn't apply much to boat trailer tires, the heat
conductivity of the gas would work against tire cooling in the case of
race cars and aircraft since it would serve to increase the rate of tire
heating in heavy brake application. Many aircraft tire failures are due
to overheated brakes, heating the wheels to the point of causing the
tires to blow out or burn, not from heat generated by the tires themselves.

Rick

James Johnson
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On Sun, 02 Nov 2003 11:05:12 -0800, "Lloyd Sumpter" wrote:

On Sun, 02 Nov 2003 00:31:47 +0000, James Johnson wrote:

Hydrogen is even better yet (better heat transfer coefficient). It is what is
used to cool the 1000 megawatt generators at power plants as air can't carry the
heat from resistance in the windings away fast enough. Just watch out for
flames or sparks. Also hydrogen tends to diffuse through the tire so you have
to replenish it more often.



I've worked at Perry, OH; Enrico Fermi, MI; Calvert Cliffs, MD; Oyster Creek,
NJ; Salem, NJ; Peach Bottom, PA as a contractor for maintenance outages and as
part of the operating staff for 2 of them. They ranged from 600 MW to 1300 MW.

In all of these the internal cooling for the generator was recirculating gaseous
hydrogen. The H2 is recirced through the windings picking up heat and then pass
through water cooled heat exchangers to give up the heat. The systems are
built into the generator casings so unless you were part of the disassembly you
would not know of the specifics.

To use air the generators would have to be much larger to provide sufficient
surface area to remove the heat generated by resistance in the windings (i.e. it
is cheaper to build it this way). They have elaborate bearing seals, and no
oxygen inside (nitrogen purged for maintenance or prior to filling for
operation) to prevent combustion. So doggie-donuts yourself.

JJ

Having worked in a 1000 MW generating station, I can safely say this is
doggie-donuts. I wouldn't have hydrogen (or any explosive gas) within
100ft of a high-power generator!

Lloyd Sumpter

James Johnson
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