Evaporative Cooling

[Dragonfly]

Here's some Information from Sapphire Technology, a graphic card maker and afaik the first to implement vapor cooling:
.......................
The greatest advantage of this system is that it requires no help to work, it starts and runs on thermodynamics =D>. Forced air flow is necessary, however, so it isn't completely free.

I am afraid you are trying to compare an absolutely static device with single flat surface and maximum thermal contact to a complex machine with irregular shapes, moving at fast speed and constantly influenced by accelerations in all three planes.

Electronic chips cooling systems use either gravitational or osmotic (wick) principle for returning the liquid phase back to the heat source. I for one can't imagine how it can be achieved for an ICE with the same simplicity and efficiency.

[CBeck113]

Here's some Information from Sapphire Technology, a graphic card maker and afaik the first to implement vapor cooling:
.......................
The greatest advantage of this system is that it requires no help to work, it starts and runs on thermodynamics =D>. Forced air flow is necessary, however, so it isn't completely free.

I am afraid you are trying to compare an absolutely static device with single flat surface and maximum thermal contact to a complex machine with irregular shapes, moving at fast speed and constantly influenced by accelerations in all three planes.

Electronic chips cooling systems use either gravitational or osmotic (wick) principle for returning the liquid phase back to the heat source. I for one can't imagine how it can be achieved for an ICE with the same simplicity and efficiency.

You don't have to be afraid, I am doing exactly that - how else are new technologies "adapted"? And you're right, it can't work at the moment - we both have given good reasons why. But, if the advantage was good enough, the engineers would design the engine + ERS to fit the cooling system, and the cooling system to the car, and then it could work.

[Dragonfly]

@CBeck113
As I said previously, I don't think it is impossible. But I guess it will mean a fundamental change in the design of the engine cooling. On the other hand quick transfer of heat with small losses away from the engine might become the reason for different ways of utilizing heat energy. Who knows.

[riff_raff]

F1 regulations require a 3.75bar pressure limiting valve on the engine coolant (water) circuit header tank, and does not allow the coolant circuit to make use of the latent heat of vaporization of the fluid. So the system described would not seem to be suitable for F1 engines.

Even if using steam cooling for the engine was permitted, there are other things to consider. For one, the aluminum alloys used in current F1 engine blocks and heads begin to lose significant strength and suffer increased thermal fatigue at temperatures above about 350-400degF. A steam coolant system could easily produce temperatures high enough to create thermal fatigue problems in the highly stressed areas of the aluminum engine block and head structures.

[trinidefender]

F1 regulations require a 3.75bar pressure limiting valve on the engine coolant (water) circuit header tank, and does not allow the coolant circuit to make use of the latent heat of vaporization of the fluid. So the system described would not seem to be suitable for F1 engines.

Even if using steam cooling for the engine was permitted, there are other things to consider. For one, the aluminum alloys used in current F1 engine blocks and heads begin to lose significant strength and suffer increased thermal fatigue at temperatures above about 350-400degF. A steam coolant system could easily produce temperatures high enough to create thermal fatigue problems in the highly stressed areas of the aluminum engine block and head structures.

Riff raff I think you misunderstand how evaporative cooling works. The water starts off in a liquid state under pressure in the engine. It flows through and gets heated up. After it leaves the ICE it flows to an expansion chamber. As the pressure drops in the chamber the boiling point goes down. The water boils into steam which converts a fair portion of heat energy. The steam then passes through a condenser where the temperature drops just enough to turn back into liquid state. This liquid is then placed under pressure once raising the boiling point and then sent back through engine.

If you bothered to read the discussion from before then you will see that we know it is against current regulations but that it would be an interesting idea that maybe could have been incorporated.

[langwadt]

F1 regulations require a 3.75bar pressure limiting valve on the engine coolant (water) circuit header tank, and does not allow the coolant circuit to make use of the latent heat of vaporization of the fluid. So the system described would not seem to be suitable for F1 engines.

Even if using steam cooling for the engine was permitted, there are other things to consider. For one, the aluminum alloys used in current F1 engine blocks and heads begin to lose significant strength and suffer increased thermal fatigue at temperatures above about 350-400degF. A steam coolant system could easily produce temperatures high enough to create thermal fatigue problems in the highly stressed areas of the aluminum engine block and head structures.

Riff raff I think you misunderstand how evaporative cooling works. The water starts off in a liquid state under pressure in the engine. It flows through and gets heated up. After it leaves the ICE it flows to an expansion chamber. As the pressure drops in the chamber the boiling point goes down. The water boils into steam which converts a fair portion of heat energy. The steam then passes through a condenser where the temperature drops just enough to turn back into liquid state. This liquid is then placed under pressure once raising the boiling point and then sent back through engine.

the would not work, the cooling happens at the point of pressure drop so you would just extract heat from the expansion chamber

the only way to use steam to directly move heat is to have liquid evaporate on the surfaces you want
to cool, i.e. you need liquid touching all hot parts of the and enough room for it to expand

[olefud]

F1 regulations require a 3.75bar pressure limiting valve on the engine coolant (water) circuit header tank, and does not allow the coolant circuit to make use of the latent heat of vaporization of the fluid. So the system described would not seem to be suitable for F1 engines.

Even if using steam cooling for the engine was permitted, there are other things to consider. For one, the aluminum alloys used in current F1 engine blocks and heads begin to lose significant strength and suffer increased thermal fatigue at temperatures above about 350-400degF. A steam coolant system could easily produce temperatures high enough to create thermal fatigue problems in the highly stressed areas of the aluminum engine block and head structures.

Riff raff I think you misunderstand how evaporative cooling works. The water starts off in a liquid state under pressure in the engine. It flows through and gets heated up. After it leaves the ICE it flows to an expansion chamber. As the pressure drops in the chamber the boiling point goes down. The water boils into steam which converts a fair portion of heat energy. The steam then passes through a condenser where the temperature drops just enough to turn back into liquid state. This liquid is then placed under pressure once raising the boiling point and then sent back through engine.

the would not work, the cooling happens at the point of pressure drop so you would just extract heat from the expansion chamber

the only way to use steam to directly move heat is to have liquid evaporate on the surfaces you want
to cool, i.e. you need liquid touching all hot parts of the and enough room for it to expand

Right! The heated, pressurized water would require a substantially smaller radiator to reject the heat energy than the condenser with cooler water vapor.

[gruntguru]

the would not work, the cooling happens at the point of pressure drop so you would just extract heat from the expansion chamber, the only way to use steam to directly move heat is to have liquid evaporate on the surfaces you want
to cool, i.e. you need liquid touching all hot parts of the and enough room for it to expand

Yes - little nozzles inside the water jackets, spraying water on all the hot surfaces.

In the condenser you have the opposite - large areas of cool surface condensing steam back to liquid.

[langwadt]

the would not work, the cooling happens at the point of pressure drop so you would just extract heat from the expansion chamber, the only way to use steam to directly move heat is to have liquid evaporate on the surfaces you want
to cool, i.e. you need liquid touching all hot parts of the and enough room for it to expand

Yes - little nozzles inside the water jackets, spraying water on all the hot surfaces.

In the condenser you have the opposite - large areas of cool surface condensing steam back to liquid.

but what would it gain? you might save a few liters of water but you'll need bigger pipes because you are moving steam instead of liquid and unless you add a great big compressor to the steam exiting the engine you can't make the
radiators any smaller

[gruntguru]

Exactly. The only gain is reduced coolant mass.

[wuzak]

the would not work, the cooling happens at the point of pressure drop so you would just extract heat from the expansion chamber, the only way to use steam to directly move heat is to have liquid evaporate on the surfaces you want
to cool, i.e. you need liquid touching all hot parts of the and enough room for it to expand

Yes - little nozzles inside the water jackets, spraying water on all the hot surfaces.

In the condenser you have the opposite - large areas of cool surface condensing steam back to liquid.

but what would it gain? you might save a few liters of water but you'll need bigger pipes because you are moving steam instead of liquid and unless you add a great big compressor to the steam exiting the engine you can't make the
radiators any smaller

The idea, in aircraft at least, was to eliminate the need for a conventional radiator and thus reduce drag.

[autogyro]

Aircraft racers use full loss systems in many cases.
They carry a tank of coolant and have no radiators.

[wuzak]

Aircraft racers use full loss systems in many cases.
They carry a tank of coolant and have no radiators.

Some did, like the Messerschmitt Me 209 record breaker from 1939. It was said to have left an impressive trail of steam behind.

Others, like the Schneider Trophy racers didn't. Large areas of their wingsm fuselage and pontoons featured surface radiators that acted as condensers.

Sevral British prototypes were built around the evaporatively cooled Rolls-Royce Goshawk - a derivative of the Kestrel. This included the Supermarine Type 224 "Spitfire", the failed predecessor to the legend.

The actual Spitfire, the Type 300, was originally proposed with a Goshawk with the leading edge of the wing set aside as the condenser.

In Germany, the Heinkel He 100 was evaporatively cooled. It included a small auxiliary radiator, whih was retractable, for when the surface radiators were insufficient.

The obvious downsides to closed loop evaporatively cooled systems in war machines is that much of the airframe that could be used for storing fuel and ammunition is given to cooling, and the large area makes to probability of battle damage to the cooling system very high.

[Tommy Cookers]

presumably EC needs suitable detail design of the engine, is there a reference to race (not record) aircraft using it ?
surely the Schneider Trophy planes eg British and Italian were not (intentionally anyway) EC

the historical use of EC in performance aircraft seems related to the use of radiators fitting the form of the aircraft
though such 'surface' radiators were already established with liquid cooling
surface radiators naturally have plenty of area on the hot side, this would be needed with EC, but not with LC
normal radiators up to the mid 30s were about 10x worse in heat transfer metal to air than in heat transfer liquid coolant to metal
so aero drag was very high, this penalty was then greatly reduced by improved radiator design and construction
interestingly, the USA had surface radiators in squadron service in 1924, but found this impractical
by 1930 100% Glycol (Prestone) was used (unpressurised), a much higher BP allowed conventional radiators 70% smaller than usual
Glycol was unavailable to other countries, eg the RR Goshawk engine was designed for EC

these all were replaced with a 30% Glycol pressurised system with the improved radiators
only Heinkel persisted with prototypes using EV and surface 'radiators' into WW2
and then conventional radiators were designed able to produce thrust at high speeds, enough to cancel drag

the main benefit of the standard Glycol % in pressurised systems is as anti-freeze
(very high Glycol % is needed for a substantially raised BP and this coolant blend has a much lower SHC)
anyway water shows better than predicted cooling due to small-scale 'nucleate boiling'

in F1 EV would make sense only with surface radiators ?
and rules preventing DF benefits from other radiator arrangements
in current F1 the pressure is capped at rather a high level
this implies a low % of Glycol (or none ?)
the BP gain due to pressure will be high with water alone, and very little better with added Glycol

[langwadt]

presumably EC needs suitable detail design of the engine, is there a reference to race (not record) aircraft using it ?
surely the Schneider Trophy planes eg British and Italian were not (intentionally anyway) EC

the historical use of EC in performance aircraft seems related to the use of radiators fitting the form of the aircraft
though such 'surface' radiators were already established with liquid cooling
surface radiators naturally have plenty of area on the hot side, this would be needed with EC, but not with LC
normal radiators up to the mid 30s were about 10x worse in heat transfer metal to air than in heat transfer liquid coolant to metal
so aero drag was very high, this penalty was then greatly reduced by improved radiator design and construction
interestingly, the USA had surface radiators in squadron service in 1924, but found this impractical
by 1930 100% Glycol (Prestone) was used (unpressurised), a much higher BP allowed conventional radiators 70% smaller than usual
Glycol was unavailable to other countries, eg the RR Goshawk engine was designed for EC

these all were replaced with a 30% Glycol pressurised system with the improved radiators
only Heinkel persisted with prototypes using EV and surface 'radiators' into WW2
and then conventional radiators were designed able to produce thrust at high speeds, enough to cancel drag

the main benefit of the standard Glycol % in pressurised systems is as anti-freeze
(very high Glycol % is needed for a substantially raised BP and this coolant blend has a much lower SHC)
anyway water shows better than predicted cooling due to small-scale 'nucleate boiling'

in F1 EV would make sense only with surface radiators ?
and rules preventing DF benefits from other radiator arrangements
in current F1 the pressure is capped at rather a high level
this implies a low % of Glycol (or none ?)
the BP gain due to pressure will be high with water alone, and very little better with added Glycol

water is better that pretty much anything else, 100% glycols boiling point is ~200'C at 1bar so you don't need a
pressurized system