Twisting cooling fluids...

[Externet]

I believe a limiting factor in developing higher efficiency engines is sticking since day one,

to use water as coolant.

 

My point is replacing water based coolant in ICE engines, -An oil cooled engine- with the most convenient

transmission fluid.

or diesel,

or kerosene,

or transformer oil,

or refrigeration oil,

or hydraulic fluid,

or some other petroleum derivated,

or a blend of the above

-but no water content at all-

 

Which can:

 

- Eliminate boiling at 'normal' operating temperatures,

- Eliminate rust progress or prevent it,

- Eliminate pressurized circuits,

- Eliminate freezing, no specialized orange, green, whatever coolant additives,

- Increase efficiency with hotter combustion chamber if desired,

- Even used transmission fluid at $0 is good enough,

- Better heat transfer at hot surfaces due to increased wettability

- No more overheating/blown head gaskets perhaps ?

- What else ?

 

The thermal conductivity and viscosity properties of some thin oils as transmission fluid that may be near to water, as cooling is its primary task in a transmission, which can run hotter than an engine.

 

Now, are the considerations to observe :

- Hoses should be oil resistant, not the kind meant for just hot water, obviously.

- There is some rubber and seals in engines cooling passages; as there is rubber inside transmissions too.

- Larger volume radiator to compensate difference in heat transfer parameters compared to water ?

- Faster circulation pumping to compensate difference in heat capacity compared to water ?

- Different pump impellers to compensate difference in viscosity compared to water ?

- What else ?

 

-----> In other words, how would you, thermodynamics expert, replace water or water-based coolant

with a petroleum-based coolant for an ICE engine ?

 

Few figures I have been able to find:

 

Water

Heat capacity = 4.2 @ 100C

Thermal conductivity = 0.58 @ 100C

Viscosity @ 55C = 0.55 cSt

 

20W engine oil @ 100C

Heat capacity = 3.1 cP

Thermal conductivity = 0.15

Viscosity = 6 cSt

 

Kerosene @ 100C

Heat capacity =

Thermal conductivity = 0.15

Viscosity = 6 cSt

 

Transmission fluid @ 100C

Heat capacity =

Thermal conductivity =

Viscosity = 3.5 to 7 cSt

 

Diesel fuel #2 @ 55C

Thermal conductivity =

Heat capacity =

Viscosity = 1 to 4 cSt

 

Therminol 66 transformer oil

Specific heat = 0.4

Viscosity =

 

Refrigeration oil

Thermal conductivity = 0.14

Heat capacity =

Viscosity =

[Enthalpy]

I wouldn't replace water at all!

 

Please show me any oil that cools as well as water does.

 

Then, tell me how flammable a thin oil is.

 

And why should a thin oil boil less readily than water?

[CaptainPanic]

I agree with Enthalpy.

Water has a nice combination of low viscosity, relatively high boiling point, and a huge heat capacity.

 

For efficient heat exchange, you need a low viscosity, or else the flow in your tubes of your car's radiator and inside the engine will not be turbulent, and therefore heat exchange will be horrible.

 

And with oils, you replace a boiling problem with a decomposition problem. If your oil gets too hot, it will not boil - that's true. Instead, it will carbonize and form a black muck, blocking your radiator...

[lassez]

To run a engine at higher temperature the common way is to rise the pressure in the cooling system, it is used today in the Volvo heavy trucks engines they probably use a temperature of 110 C.

 

If you use oil, you need turbuletors in the heat exchanger as the oil do not have as good internal heat distribution as water have. You need to turbulate the oil so that as mush as possible of the volume is exposed to the walls i the cooler.

Edited November 19, 2012 by lassez

[Externet]

Resurrecting the topic; just found someone is doing what I was after, and been after, for maaaany years. Not from petroleum , but :

 

----> http://www.evanscooling.com/

 

Related :

http://www.alfabb.com/bb/forums/spider-1966-up/190071-evans-waterless-coolant-jay-lenos-website.html

http://www.bimmerfest.com/forums/showthread.php?p=5964971

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=258888

 

And partial composition :

http://www.hrpworld.com/client_image...pdf_3415_3.pdf

 

And very pretty data :

 

www.dow.com/PublishedLiterature/dh.../0901b803800479d9.pdf

 

http://www.dow.com/ethyleneglycol/about/properties.htm

 

 

So no water in coolant seems real. Opinions ?

Edited February 13, 2013 by Externet

[Enthalpy]

Polyethylene glycol is used mixed with water. It's a standard hydraulic fluid, also used frequently as a coolant.

[Externet]

Thanks.

The coolant these people market is about 68% ethylene glycol + 30% propylene glycol + corrosion inhibitors

 

Polyethylene glycol is not in the picture.

[Enthalpy]

Without water, ethylene glycol is seriously viscous, which makes it a much worse coolant than water. Because turbulence is essential to heat transfer, and also because more pressure is lost. As well, the heat capacity is worse than water.

 

It's also hygroscopic, so you end with some water in the fluid, making it corrosive as well.

 

In short: poor coolant. Less efficient at 120°C than water at 70°C, and your device now runs hot.

 

And I really don't see why one should search for a coolant better than water. Many thousand people have already tried and failed. You probably won't get a better answer from a forum.