REFRIGERATED Intercooler-needs input

Okay, here it goes. I've seen a couple ideas floating
Around- can you use your A/C compressor to cool you charge?
From what I've seen people have the wrong way of going
About it and conclude that it is impossible. I believe otherwise being a refrigeration tech, working on industrial equipment every day. My idea is a simple one using today's existing
Technology. A few questions I have is what are our compressors rated (in HP?) could weuse a larger compressor? How much HP is being used to turn the compressor? Can we overcome the power lost with the colder inlet temp and extra weight of the copper pipes, fans, chiller, and Condenser?

Secondly you need an ATW Intercooler to make this work. ( I also have an ATA idea as well.)

This is a chiller barrel, how it works is there is a thermal expansion valve prior to the inlet ( small titanium pipe sticking out) water/glycol- or in our case engine coolant goes into one side of the PVC barrel, heat is evaporated and the cooled liquid comes out the other side and then travels to the ATW IC. This would help eliminate heat soak. By moving the heat from the engine coolant to the refrigerant. You can't get rid of energy - but you can move it around.
what you see here is I took the barrel apart, there is an inlet(liquid line) and an outlet (suction line) for the refrigerant there is also a place to put your thermostat.
The other part has an inlet/outlet for your coolant. That's a brief summary. Questions comments are welcome.

I'm guessing that this is to vague? I'll get on a PC and draw up the design so it will be Easyer to visualize. I do believe with enough info on the components I could make this work.

Got my attention ....

I think I read about something similar years ago but I believe the power lost due to the load of the AC pump is greater than the power gained by reduced air temps.

I'd like to know how much power the compressor uses ( usually rated in HP)
I'm Sure someone has a dyno sheet AC vs no AC.
Some evaporators are -40deg F . Imagine... Your IC would be a block of ice..
Takes a lot of HP, and refrigerant to make an evap that cold though.

I'll post up the ATA idea soon, it's less complex and lighter weight.

Having driven my car in -25C with -35C windchill recently I can confirm a noticable improvement in power. The intercooler doesn't even have a chance to get mildly warm to the touch lol.

Yeah, I'm In Maine and the temp varies from -25 to 105. Rigs run
Stronger on cold days, as long as you let it warm up.
The refrigerated system has the advantage or being thermostatically controlled so its neither too hot or too cold.

I experimented with a refrigerated intercooler, main issue was condensation build up and poor fuel atomization. In the end cooler charge is better to an extent, but not this far.

All the units I work with either have a condensate drain/pan or are insulated.

Killer Chiller has made units like this for some time.

http://www.killerchiller.com/

The thing here is that eventually you are limited by your intercooler's thermal efficiency. I dont care how cold the water gets, eventually you reach a point of diminishing returns. Hell if you ran 30* coolant through your intercooler, your charge temps will only lower respectively to how well your intercooler can transfer heat. Low RPMs will see very low AITs (which tend to harm fuel mileage) and at high airflow values the charge temperature will show drops, but not ones that are significant enough to merit complicated and heavy systems versus ones that dont employ refrigerated systems.

On top of that, most comparison gains shown from refrigerated A2W coolant have been done on vehicles already heatsoaked on the dyno with questionable airflow across them. Mustang guys have been notorious for this, the cobra came with a factory A2W system that if left to idle for long periods of time would easily heatsoak. A refrigeration system would solve this issue, however an upgrade to the heat exchanger, the pump, and maybe not letting it sit on a dyno running for so long would have probably also remedied this problem...

My recommendation would be to consider designing a proper A2W system with a decent heat exchanger, a powerful pump (I recommend a Johnson CM90), some temperature controlled cooling fans, and pretty much whatever Intercooler you can fit under your hood...

No need to go overboard on A2W intercooling, as long as it is adequate for your engines demands, I wouldn't over-think it too much they are highly efficient and capable in their own right. A lot of people already argue that An A2W system is already pushing the boundary between weight/complexity/gains in its own right, why add to that?

Consider the following factors:

-Fuel type and delivery, If you only have access or plan on using 91 octane or lower, then intercooing becomes more important. Great intercooling is not a substitute for inadequate fuel delivery if you want a reliable vehicle. Don't rely on lower charge temperatures when in reality you should be delivering more fuel...

-This will definitely not be worth it for a factory ECU or stock CT26 vehicle... The fueling system and turbo already flop out before the knock threshold is reached with the factory intercooler. Intercooling already is only really useful if you are breaching the knock threshold. I would say unless you are over 500whp dont bother trying to use refrigerated A2W just go with a well designed A2W or a front mount... Intercooling is NOT a power adder, its a power reinforcer, meaning it allows your motor to develop more power by decreasing the knock threshold and slightly increasing air density, it does not physically increase the power... only the fueling system can do that...

-Weight and complexity, If you plan on running a zillion systems to accomplish one task, consider whether or not the added weight and complexity will make up for itself by its gains.

-If you plan on making this an educational exercise, be prepared to be able to datalog. Butt-dyno doesn't count here... That means running control experiments with datalogged AIT values, and HP/Torque data.


That said, If I havent discouraged you at this point, I would really be interested in seeing the results!

Overtriped":19zn5d9y said:

All the units I work with either have a condensate drain/pan or are insulated.

Click to expand...

May be true, the system I developed was rather unorthodox

Consider if the materials from your work are able to handle engine temperatures, vibration, chemicals etc. By all means its fun to tinker
but from a performance aspect traditional intercooling methods are great once the system is designed well.

The idea I had in my head is that you could Run a leaner ATF ratio and not have to worry about melting and pre detonation( unless you sprang a leak or toasted the compressor- which there should be safety switches in place)
this would replace meth/water injection- you could use the condensate to further Cool your inlet. It does add a couple extra parts. Relatively not much more complex than your AC though. Defiantly valid points being brought up here. I did see one other ATA prototype that did not work very well, I really didn't like there design though.

On the contrary, you would need to run a RICHER air mixture due to the cooler charge containing more oxygen. Secondly, the cooler the charge the poorer the fuel atomization requiring an even more rich mixture

Well the killer chiller defiantly works.. Very good reviews!!
I didn't know about the atomization. it's a lazy blizzard day and Im not on my A game.
Doesn't a leaner mixture burn hotter? You want enough fuel To keep it cool, but not too much to get better efficiency. I learned this by tuning carburetors. I may be wrong but with the same amount of pressure at a cooler temp replaces the extra fuel you need to lower combustion temps?

klue":900e5acl said:

On the contrary, you would need to run a RICHER air mixture due to the cooler charge containing more oxygen. Secondly, the cooler the charge the poorer the fuel atomization requiring an even more rich mixture

Click to expand...

+1
Colder intake charge means the density of the airflow increases....you get more oxygen for the same given space, this need to be offset with fuel, so the colder it gets the more fuel is needed

Certainly not doubting weather or not it works, as I said I had run my own refrigerated system but we had issues with condensation in the humid hot Caribbean climate. On a good carburetor setup the fuel atomization is better than on a fuel injected engine(at least the 3sgte). The fuel has time to properly mix with the air and you get a good power result.

We are getting into grey areas I dont like, using words like lean vs rich is very vauge but for the sake of argument lets continue. Yes a lean mixture will burn hotter than a rich one, and generally produce a higher EGT all other things the same. But this is kind of straying from the point I was originally get at.
As you lower the temperature further and further, the oxygen content increases as the charge density does. So you need to add more fuel to maintain the same AFR regardless of weather you would consider it lean rich or stoich. This is what produces the bigger bang, and more power associated with colder air nothing else (unless you can run more timing which is a whole different discussion). Now the problem I see with trying to run lean + this super cool charge we are creating is as you cool the charge further and further the atomization(suspension of fuel VAPOR withing the air fuel mixture) becomes poor. In other words instead of a nice fuel vapor, the fuel remains big droplets which do not burn the as complete and explosively as a nice mix.

To counter this poor mixture you need to add even more fuel to get the engine happy, an example of this is a cold engine requires a significant amount more fuel (richer AFR) to run properly even though it seems kind of counter correct. I guess that sums up the issue with the atomization I had, In my experience alone. I can not say for yours or how well it will run, but hopefully I can share some info that you may find useful in your build. It is never my objective to discourage blossoming ideas, go for it!

Luke

My biggest concern is that because charge temps will be so low at idle, (well below ambient) that fuel mileage will really suck. That coupled with the more than likely modest drops in IATs under full boost when compared to just a well designed A2W system makes me wonder if the effort is worth all the fuss. Im totally prepared to eat crow here, but I would really love to see someone make a feasibly effective and inexpensive refrigerated charge cooler that makes it worth it.

Ill throw something out here, has anyone tried running refrigerant direct through laminova or just a striaight AC evaporator and totally bypassing the water system as a whole??? That to me would seem much more effective because you could potentially throttle the refrigerant flow to restrict over-cooling under idle conditions... Ice formation and excess condensation could be managed through throttling refrigerant and a thermister to monitor incoming charge temperatures and refrigerant temperature. Water in the intakes is not that bad of a thing anyways... as long as it doesnt form ice...

l0chow

we had the compressor set up to turn off below 1500rpm and above 6500(seemed to grenade after that lol). At the same time fuel demands at idle are much less than load conditions so with the right tuning you can run a much much leaner mixture

So your thinking get rid of the ATW and flooding
The Intercooler with liquid refrigerant? That's a lot
Of gas, would have to have a surge tank to
Reserve the gas for when you need it.
Typically there would a solonoid that is actuated by the thermostat via thermistor at a
Determined setpoint. (The thermistor is placed in the evap) - regulating the temp is doable. Also the TXV has a power head that measures evap discharge temp and meters the amount of refrigerant going through The evap. Once the system satisfys Temp the solonoid will close and the system
Will shut down on low pressure. Once the pressure rises
It will either pump down again to the receiver/condenser,
Or open the solenoid and start the cooling process again. On a side
Note I wouldn't need it on a day like this. System Might not even run.
Here is Ol' Reliable

Just remembered that there are also "static" evaporators that actually use the frozen condensate to further cool and reduce the load. Coil covered in ice isn't always a bad Thing... As long as your compressor isn't being slugged with liquid, which there are ways around That by adjusting your superheat and by adding a suction line accumulator which helps the liquid refrigerant boil off to vapor, just prior to the compressor. Liquid refrigerant is a compressors worst enemy. It will migrate the oil and wash the oil surfaces leading to failure. This is what happeneds
To a compressor slugged with liquid-
that's a 20hp 4 cyl copeland( obviously much different then ours
But the same thing would happen.)