Barrel style water air intercooler
12-17-2009, 06:25 PM
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12-17-2009, 07:21 PM
#47
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I understand what you mean but you are using certain terms incorrectly. The lake water intercooler will bring the intake temps bellow ambient but that doesn’t make it more than 100% efficient. If it would bring the intake temperature bellow the temperature of the lake water, ONLY than you can say it is more than 100% efficient. Same goes for air-air intercoolers too, then can never bring it to bellow ambient but can get it much closer than regular A-A units. None of them can be more than 100% efficient, it’s physically impossible. 100% is the maximum regardless what you are referring to. Maybe there are some examples in quantum physics where this is different but in the real world, 100% means “the absolute maximum”. Maybe in the boating world, they use over 100% efficiency, to explain certain instances but that doesn’t make it correct.
For example, if an engine is running at 100% efficiency, it converts absolutely all the energy from the fuel to rotational force. Now, if it’s running at 110%, that would mean it actually is starting to make more energy that it consumes and this is impossible.
Also, I truly beleive that an ideally sized air to air intercooler will alway be more efficient than an idealy sized water to air one. A-A has less boundries to cross and that's the only reason it will be more efficient.
For example, if an engine is running at 100% efficiency, it converts absolutely all the energy from the fuel to rotational force. Now, if it’s running at 110%, that would mean it actually is starting to make more energy that it consumes and this is impossible.
Also, I truly beleive that an ideally sized air to air intercooler will alway be more efficient than an idealy sized water to air one. A-A has less boundries to cross and that's the only reason it will be more efficient.
I understand your point. However, I think you are looking at things in a different light. The fact is, the air started the intake charge process before the compressor at ambient temperature, and this is the baseline. The air did not start the process at the temperature of the water. It started at the temperature of ambient air. It only got hotter because it was compressed, nothing else.
The Delta T is only measured from base (90Deg), as this is the temperature the air started at, and the difference is measured from that. You cannot use the temp of the water of 60Deg as base, as the water has nothing to do with the process yet. The heat added to the compression of the ambient air takes the charge to 140Deg. That is the scientific way to do the calculation, and if you doubt me, you can check any thermodynamic physics formula for measuring temperature differential. If it were otherwise, the heat gain from the compression of the air would be from 60Deg (Water) to 140Deg (Outlet Compressor Temp), or 80 Degrees. This would mean the compression of the air added 80 Degrees, when in fact the air started Compression at 90 Degrees, and ended compression at 140 Degrees fora gain of 50 Degrees, and not 80 Degrees as you are eluding to..
I am certain that you are confusing measuring efficiency with total temperature difference, and the baseline used in the calculation. However, your assumption on what the base state is in this case is incorrect. The air did not start the process at the temperature of the coolant water, it started it at ambient temperature.
Anyway, we can debate the outlet temperature all day, and if you do not use the same scientific methodology, we will arrive at different places.
The fact will still remain however, that it is physically possible to cool the outlet charge from a compressor to lower than the intake air temperature of the same compressor from ambient air using an AWIC, or liquid cooler.
This is impossible to do with an Air to Air cooler, because the cooling medium is ambient air, which has the same temperature that it started the process..
The Delta T (temperature) of the liquid used as a coolant, and the charged air allows this to happen the way I described it.
Marine applications have been doing this for years, and commercial as well as race boats are able to utilize this to keep their engines cool. They use the ocean, and or lakes, which is much below the ambient air to cool the heated air from the compressor.
On your point of 100% efficiency on an engine, I again think you are mixing apples and oranges from what I interpret you are trying to say... Another poster made a comment of greater than 100% VE, and this is related to the Volumetric Efficiency of the engine, which can be achieved by the flow and velocity of the intake charge into the head and then combusted.
It is possible to achieve this with naturally aspirated motors, because there are several miles of atmosphere pushing down on the motor, and all else at sea level, this is about 14.7psi, or 1 atmosphere of pressure. The pulse waves of the valves can be used to additionally compress the intake charge when the intake runners, ports, and head is properly designed and built.
I think this is what you are getting mixed up with being 100% efficient in the engine comment. It is entirely different. The cylinder of 500cc's of air can be made to have 600cc's due to the pressure wave of the valve events, and the velocity of the intake charge pressing it into the cylinder.
This is exactly what happens when an engine uses forced induction. There is mechanical force compressing the air. The force in the NA version, is from the pressure wave, velocity, and other resonance tuning used to compress the air.
If you don't believe it, it still does not make it false... Like you said, it's just physics...... I can't see a pressure wave, but I know it's there, and I can measure it with an instrument. You can too, just place a pressure inducer measuring device in your intake tract with the engine running, and data log. you will see its relation to the opening and closing of the intake valve.
Cheers,
12-17-2009, 07:25 PM
#48
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12-17-2009, 07:52 PM
#49
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If you're gonna cheat Erik, then use liquid CO2, and freeze the A:A Core to make it lower than ambient...!
