COOLING SYSTEM
7.11
CHARGE AIR COOLING DESIGN GUIDELINES
The air to air CAC system should be designed for the highest horsepower engine offered in
the application. The same system can be used for derated versions of the engine, which offers
the following advantages:
□
Reduces the number of components in the manufacturing and part systems
□
Lower power engines may achieve even greater fuel economy from the additional reduction
in engine intake air temperature
□
Extends engine life
The following guidelines will assist in the design and selection of the various components that
make up the charge air system. It is critical that these components offer maximum air temperature
reduction with minimal loss of pressure. The integrity of the components must provide for long
life in its operating environment.
Air system operating parameters such as heat rejection, engine air
fl
ow, air pressure, maximum
pressure drop, and minimum temperature loss are available on the published Engine Performance
Curves (sheet #2).
Charge air cooler considerations include size, cooling air
fl
ow restriction, material speci
fi
cations,
header tanks, location, and fan systems.
7.11.1
SIZE
The size of the heat exchanger depends on performance requirements, cooling air
fl
ow available,
and usable frontal area. Using the largest possible frontal area usually results in the most ef
fi
cient
core with the least amount of system pressure drop. Consult your supplier to determine the
proper heat exchanger for your application.
7.11.2
COOLING AIR FLOW RESTRICTION
Core selection and location must meet charge air system temperature and pressure drop limits,
and must be compatible for good coolant radiator performance. Charge air coolers have a cooling
air
fl
ow restriction typically between .19 and .37 kPa (0.75 and 1.5 in. H
2
O).
7.11.3
MATERIAL
Most charge air coolers are made of aluminum alloys because of their light weight, cost
advantages and good heat transfer characteristics. In general, aluminum, aluminized steel, and
stainless steel are recommended materials for CAC system design. Other materials may be used
with approval from DDC Applications Engineering. The use of untreated steel and other similar
material is not approved because of rust formation.
7-24
All information subject to change without notice.
(Rev. 03/06)
7SA250 0603
Copyright © 2006 DETROIT DIESEL CORPORATION