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timabb
02-04-2017, 03:54 AM
Hi,
I've come here to get some help for an a/c system Im designing for my project truck, a single cab off road exploration/camping vehicle (A '89 Unimog). The operating environment it will be exposed to is extreme; ambient temperature frequently +45 degrees C and high humidity. Aswell as the heat, it will be exposed to dust and vibration, so it will need to be a rugged system. So basical its function will be the same as any vehicle a/c system with one difference. I want to use the refrigerant to chill the diesel fuel as much as possible before it enters the engine. To do this i will build a tube/shell heat exchanger unit, with the diesel flowing through the tubes and the cold refrigerant passing through the shell. Attached is a link regarding the heat exchanger design concept.
https://en.wikipedia.org/wiki/Shell_and_tube_heat_exchanger

This is an experiment to see if it will lower exhaust temps and therefore allow for more boost and fuel, resulting in more power :)
So i need to design a cooling system that will chill the fuel and also cool the cab (single cab).
Now i don't have a very extensive grasp on all things a/c, all i can figure is I want to fit the biggest remote condenser unit i can. So far i think i will go with this 39000 BTU RedDot condenser

http://www.partdeal.com/red-dot-model-r-9720-39-000-btu-remote-mount-condenser-24-vdc-with-in-line-drier-r-9720-12-24p.html?zmam=74973193&zmas=1&zmac=99&zmap=77199996&gclid=Cj0KEQjwqtjGBRD8yfi9h42H9YUBEiQAmki5Ojt3NO3jn3nhMH7A0ql9pGvXCR4uACwz8Bel-TONERMaAlfi8P8HAQ

And as for the compressor, a guy who has an a/c retrofit kit for the truck, uses the a Unicla 200 Series compressors.
http://www.unicla.com.ar/pdf/C0905-HiRes-200Series.pdf

What i need to know is, would the size of this compressor suit the capacity of the condenser, or do i need to go bigger?
And what gas should i use? From what I've seen, here in Australia, there is R134a or R404a, is there a better option.

Thanks for your help!
Tim.

HVACRsaurus
02-04-2017, 04:23 AM
Hi Man,

Unreal!

Here my 2cents..

AC for Cab - Great! I'd suggest searching for a "Package" or "kit" I'm sure you know how to google.

Chilling diesel line - ok, I grasp the concept, but I wouldn't bother. Sure, I own a 4wd, I've been off-road but I just wouldn't bother.

For every litre of diesel you squirt into the engine, about 1000000 cubic decilitres of air is used for combustion - one litre of supercool diesel is going to drop that exhaust temperature by exactly five eights of a nano celcius.

Ever heard of something called "cost versus benefit"? How much is this supercooler going to cost?? 2k? 5k? How much spiced rum can you buy same - pretty sure I could forgo cold deisel for spiced rum.

Aaand, to me, it just one more thing to crap out on the side of the road..

Happy tinkering