Aftercooler?

[RT66DOC]

What's the difference between aftercooler and intercooler? For example, some marine diesels are aftercooled and some are intercooled. Two that come to mind are Detroit Diesel 12V71-TI and 12V92TA.

 

[RustyJC]

In reality, nothing as it has to do with our application. In the compression business, intercooling is cooling of the process air or gas between stages of compression. Aftercooling is cooling of the process air or gas after the final stage of compression.



Intercooling is used in a lot of automotive/truck terminology because the air is indeed compressed again after it is cooled - by the piston on the engine's compression stroke. Caterpillar, however, refers to many of its gas engines as being of the TA configuration - turbocharged and aftercooled.



If you accept Cat's terminology, a twin turbo series setup with a cooler after each turbo would be intercooled after the low pressure turbo but aftercooled after the high pressure turbo.



In the case of the Detroit Diesel, a cooler located after the turbocharger(s) would be an intercooler, while a cooler after the blower would be an aftercooler.



Rusty

 

[RT66DOC]

Cool. So now I know. Thanks, Rusty.

PS Another question - Are all those DDs [8,12,16] 2-cycle diesels like the 6V92?

 

[RustyJC]

The -53, -71, and -92 series Detroit Diesels are all uniflow-scavenged 2-strokes with the ring of intake (scavenging) air ports in the cylinder and the exhaust valve(s) in the cylinder head.



Rusty

 

[RDupree]

water to air or air to air?

ok,my question is: i have an 8. 3 cummins with an water to air aftercooler,i'm putting it into a truck that has a air to air aftercooler on it. so,which one should i use,air to air? or water to air? or both? anybody?

 

[RustyJC]

You could use either, all else (sizing, etc) being equal. The water-to-air aftercoolers are generally used where space is a problem or where a liquid cooling circuit already exists that can be used. If you already have an air-to-air aftercooler of sufficient size in place and can plumb to it pretty readily, then you can eliminate the complexity of the extra heat exchanger, water pump, piping, etc. of the water-to-air aftercooler.



Rusty

 

[RT66DOC]

I will say, a pair of DD 12s [in a boat, for example] sound mighty fine. Kind of like a brace of V-12 Ferraris on steroids.

 

[nickleinonen]

charge air cooler, intercooler, aftercooler... . same thing, different name