MTFCA Forum

Warning: scientific content.

An interesting article in Science Daily recently about a 500% increase in thermosyphoning heat exchangers, see https://www.sciencedaily.com/releases/2 ... 131432.htm. The article calls it a turbulent heat exchanger but it is the same thing as a thermosyphoning system.

A 1% addition of a chemical, hydrofluoroether, causes bubbles of this chemical to form on the hot side which cause the water to rise up more rapidly. On the cold side the hydrofluoroether turns back into a liquid and sinks along with the water.

Hydrofluoroether is not available for non-industrial uses and then only in 55 gallon drums. Putting that aside for the moment, there are several questions to answer:

• Would it work in a Model T?
  Would it cause the engine to run too cool?
  Is it an added and unnecessary complication to a simple system that has worked well for 100 years?
  Is there another chemical, more readily available that would work as well?
  Does steam do the same thing at zero cost?

I'll pick "C".

So basically you get a lava lamp sort of thing going on in your engine? Neat.

The report says it boosts efficiency of turbulent flow cooling. I am pretty sure that thermosyphon is laminar flow. In any event, you would be dealing with a totally sealed system, which we don't have. Not to mention exposure limits in the 700 ppm range. I am very happy to avoid organic solvents and will continue to add normal coolant occasionally.

Since engines typically are more efficient the hotter they run, a 200F water temp is about ideal when you balance efficiency with temps that lubricants retain their designed properties. I would not want an engine to run at a very low temperature even if it was possible.

Interesting stuff, but of no application to the hobby.

Interesting to speculate, but good enough for 100 years is good enough.

Somebody really ought to try this! Just for science of course!

If you have an old engine that is overheating and needs a rebuild why not give it a try!

Tiger Tim wrote: ↑

Sun Aug 04, 2019 9:59 am

So basically you get a lava lamp sort of thing going on in your engine? Neat.

To expand that idea, what about a glass radiator and colored water? Be a real show stopper in a parade................ Seriously though, Ford's system worked well in over 15 million cars. Why fix what ain't broke?

Other than the fact that hydrofluoroether evaporates at 142F, and is a vapor-degreasing chemical, it sounds like a really REALLY swell idea!

I learned a long time ago if water flows through the radiator, in a car, too fast it doesn’t have enough time to cool down. I don’t know that this would play a role in a Ts cooling system but in a pressurized system with a pump it sure does. I wonder if it’s possible in a T ?

Bubbles on the surface of what your trying to cool, can't absorb heat, so...
Would it work in a Model T?
No, for all the reasons stated above. It is intended for HVAC systems which are sealed and pressurized.
Would it cause the engine to run too cool?
The engine would run cool until the evaporation temperature of the hydrofluoroether was reached,142°F and that would be about the same time it would take if water was used.
Is it an added and unnecessary complication to a simple system that has worked well for 100 years?
Definitely a complication. It is questionable if the current "simple system" has ever worked well for everyone/anyone. If it had you wouldn't have posted this tread and the rest of us wouldn't have read it.
Is there another chemical, more readily available that would work as well?
Yes, a mixture of 2 parts Hydrogen to 1 part Oxygen in liquid form and it is readily available in quart and gallon containers
Does steam do the same thing at zero cost?
No, steam is a gas, water at 212°F. There is a general consensus to keep the engine temperature between 180°F - 200°F.

If you are really looking for an alternative coolant read about GLYCEROL
Like ethylene glycol and propylene glycol, glycerol is a non-ionic kosmotrope that forms strong hydrogen bonds with water molecules, competing with water-water hydrogen bonds. This interaction disrupts the formation of ice. The minimum freezing point temperature is about −36 °F (−38 °C) corresponding to 70% glycerol in water. Glycerol was historically used as an anti-freeze for automotive applications before being replaced by ethylene glycol, which has a lower freezing point. While the minimum freezing point of a glycerol-water mixture is higher than an ethylene glycol-water mixture, glycerol is not toxic and is being re-examined for use in automotive applications.

Significant advantages to breaking up the laminar floor with turbulence to increase the heat transfer in heat exchangers/radiators.
https://patents.justia.com/inventor/joseph-h-andulics

Scottio wrote: ↑

Sun Aug 04, 2019 3:54 pm

I learned a long time ago if water flows through the radiator, in a car, too fast it doesn’t have enough time to cool down. I don’t know that this would play a role in a Ts cooling system but in a pressurized system with a pump it sure does. I wonder if it’s possible in a T ?

Absolutely correct. Back in the flathead V-8 hot rod days, it was a common modification to drill holes in the water pump impellers to SLOW DOWN the flow, or the engine never would come up to temperature.

Hi All

There is an important statement in the article that applies here that hasn't been mentioned yet.

"The researchers pointed out that the specific additive they used -- HFE7000 -- is non-corrosive, non-flammable and ozone friendly. One limitation is that the approach only works on vertical heat exchange systems -- ones that move heat from a lower plate to an upper one. It doesn't currently work on side-to-side systems, though the researchers are considering ways to adapt the technique. Still, vertical exchangers are widely used, and this study has shown a simple way to improve them dramatically."

The modification is for HVAC heat exchangers that move heat from a low plate to a high plate.
Model T thermosyphon conditions move heat essentially side to side. The process would not work as stated in a Model T engine and radiator.

Also, as noted by others, the temperatures don’t’ work either. If the boiling point of the additive is lower than the operating temperature of the engine coolant, it will evaporate (boil) out of solution and exit via the radiator vent. This was a problem in the earlier years when using alcohol for anti-freeze. It eventually boils out of solution and the anti-freeze effect lost.

Most HVAC systems operate at a lower temperatures than 180-212 deg. F.

Drive Safe

Jeff
Nova Scotia

Scottio wrote: ↑

Sun Aug 04, 2019 3:54 pm

I learned a long time ago if water flows through the radiator, in a car, too fast it doesn’t have enough time to cool down. I don’t know that this would play a role in a Ts cooling system but in a pressurized system with a pump it sure does. I wonder if it’s possible in a T ?

Then wouldn't it also hold true that the water doesn't have enough time to heat up as well?