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BigJon3475
15-06-2007, 11:32 PM
This may be "out there" but I have had it on my mind for a while and just have not researched much. I have been thinking about the possibilities of using a air conditioning system in a turbocharged vehicle application for intercooling effects so to try and gain even more of a cooling effect for intake temps than air to air or air to water intercoolers. Is this possible? Does it use to much power to run a refrigerant system to try and cool temps for it to be effective? I know it has been done by Ford in the past with a ethanol based "Cobra" test vehicle. Supposedly the gain is 3% of power for every 10F drop (-12.22222C) in intake temps. Since air flow is variable with intake flow and engine size it would obviously have to be sized for the car and engine. Is the maximum temp you could drop across a evap. coil the limit? What if the intercooler had the evaporating system integrated into it? Just some thought on if this is an option or are air to air and air to water intercooler already more efficient or at least efficient enough to where you wouldn't gain anything form the parasitic loss from having to use horsepower to turn the compressor.

momo
16-06-2007, 12:20 AM
Compressors use a lot of power - run a small engined vehicle with and without air conditioning and see (a Smart going up a hill is a brilliant example :D ).

Pre cooling of air going over heat exchangers with evaporative means (water spray) could help with additional control and care (effect of temperature change and shock on metals etc. and corrosion/residues /dust collection with impurities in water.) Also cooling of radiator and oil cooler is another idea. I toyed with these ideas years ago when playing with classic Minis which do NOT like hot Summers :o.

BigJon3475
16-06-2007, 12:54 AM
Well in that case a atomizer spraying water meth is already very common and it drastically reduces intake temps and also effectively changes your octane level dramatically. I'm past hits point and looking for more horsepower. Water/Meth injection is probably the most important aspect to effectively cooling intake temps. I'm looking for the extra edge. I know it's probably already been thought of and tested. But who knows with the intelligence of the guys/gals in here maybe we can come to a conclusion that is worth looking into.

old gas bottle
16-06-2007, 08:40 AM
i did i little bit on this for plant machinery to cool the intake,dont think it will work ,to much hp needed to gain the cooling, but if you were to try fitting a small coil in the intake and have a bottle of liquid nitrogen in the boot operated by a switch,that may do it ?;)

TXiceman
18-06-2007, 11:07 PM
There is a whole industry based on turbine inlet cooling. Larger gas turbines used to power generators benefit greatly from lowering the air inlet temperature. These generators are multi-megawatt size and use multiple 1000 ton or larger water chillers. Large chilled water coils are place in the inlet section of the filtered air and cool the air down to close to 50 dF. In cooler weather they shut down the chillers and run on ambient air.

An alternate to the chilled water unit is to spray water in the turbine inlet to the evaporative cooling chill the air, but not nearly as cold as refrigerated air. Thes are cal turbine mist systems.

The big advantage of the mist system is it is much less expensive, but does not get near the performance of the refrigerated air system. Even with the added parasitic load from the chillers, the net result is improved turbine/generator efficiency.

Another approach has been to use a more industrial approach and use ammonia screws and a direct flooded coil to chill the air. This approach is the most efficient of all, but some turbine manufacturers worry that the ammonia in the inlet in the event of a coil leak will be detrimental to the turbine. As closely as the turbines are monitored, I doubt if this would be a problem. One way to dispose of ammonia is to incinerate it.

Ken

The MG Pony
21-06-2007, 01:47 AM
some guy made a peltier cooler for his intake manifold.

US Iceman
21-06-2007, 02:18 AM
...but some turbine manufacturers worry that the ammonia in the inlet in the event of a coil leak will be detrimental to the turbine. As closely as the turbines are monitored, I doubt if this would be a problem. One way to dispose of ammonia is to incinerate it.


Ken, since these are combustion turbines they could use some small amounts of ammonia to reduce the NOx content of the combustion gases, right?

http://www.energy.ca.gov/sitingcases/midway/documents/2000-09-08_STAFF_ANALYSIS.PDF

TXiceman
21-06-2007, 02:11 PM
That is the one point that I can not understand. Unless it has to do with where the NH3 is injected. Precombustion or post combustion.

Maybe precombustion there is a materials compatibility issue where post combustion, it just reacts with the hot exhaust gases.

Ken

US Iceman
21-06-2007, 02:39 PM
I am way out of my league on this subject, but I thought the ammonia injection was after combustion. Something about the ammonia reacting with the combustion gases to reduce the Nox.

We built a large liquid overfeed system for one turbine inlet pre-cooling system that was ammonia. I wonder if the hesitancy to use ammonia falls back into the area of old wives tales?

TXiceman
22-06-2007, 02:15 PM
The NOX emissions controls are post combustion. The turbine folks are not sure of the reaction and change of heat content of the inlet gas if it gets some ammonia mixed in with the inlet stream. When they are pushing the turbines toward the upper limits, the ammonia may cause excessive temperatures as well as attaching some of the materials.

I too have seen large liquid overfeed systems operating on ammonia for these applications.

Ken

BigJon3475
22-06-2007, 05:39 PM
http://www.enginelogics.com/cmaps.html


The link above is what got me thinking. With just a intake temp drop of 125F down from 250F without an intercooler. They were able to achieve 5.44 lbs/min. After working over the head alone they were able to get another 4 lbs/min.


I guess what I was wondering is is it possible to draw any more heat out of the intake charge than going with a injection system. Currently water and methanol with the water absorbing large amounts of heat to fight detonation and the methanol giving the intake charge a higher "octane" rating.

monkey spanners
22-06-2007, 06:45 PM
Just out of interest, what are you trying to get more power out of? and for how long? Are you injecting the water/methanol mix into the inlet manifold or spraying it on the intercooler?

Cheers Jon

The MG Pony
22-06-2007, 08:58 PM
Ah fellow online out in the vastness of the net used a couple of powerfull peltiers attached to a heat sink Alufin system to cool the air, worth a try perhaps.

BigJon3475
23-06-2007, 01:39 AM
Just out of interest, what are you trying to get more power out of? and for how long? Are you injecting the water/methanol mix into the inlet manifold or spraying it on the intercooler?

Cheers Jon

Most of the time the water/meth mix is sprayed into the intake runner. The solution actually cleans the intake the valves and the pistons with the above mentioned pluses also of absorbing heat and adding octane rating.

I'm just shooting out ideas figured I would see if anything better could come out for cooling the intake temps. The previous idea I saw on this Ford made Cobra several years back and it used the condensate off of the low pressure side to help cool the intercooler since it was a water to air setup and somehow used the refrigerant lines in the intake stream to cool the intake charge also.


Just shooting an idea out and see what comes out of it. If nothing oh well if something semi :D safe pops out maybe try it out.

theboss
12-07-2007, 01:37 AM
design a mini continuous cycle chiller and feed the hot coolant into that. Free cooling all day long utilize it anywhere.