Volvo IPS950 - Page 30

Calculation of air ducts
Example 3: IPS950, 533 kW (725 hp)
Area
calculations for one engine with a 2 m (6.6 ft) long
duct, 2 bends and an outside temperature of +20 °C
(+68 °F).
Air consumption:
Area for engine air consumption: 1.9 × 533 = 1012.7
cm
2
(156.9 sq.in)
Correction for duct length and bends = 1.41 from the
Coefficient of bends table.
This gives 1012.7 × 1.41 = 1428 cm
2
(221.3 sq.in). The
area 1428 cm
2
(213.9 sq.in) corresponds to a duct
diameter of 419 mm (16.5").
Multiply by the number of engines to calculate the area
of the engine compartment inlet duct.
Ventilation:
1 Inlet, engine compartment: Area = 1.65 × 533 =
880 cm
2
(136.4 sq.in). This corresponds to a duct
diameter of 329 mm (13").
2 Outlet, engine compartment: Area = 1.65 × 533
= 880 cm
2
(136.4 sq.in). This corresponds to a duct
diameter of 329 mm (13").
3 Correction, inlet and outlet: Air temperature = 0.7
from the Correction factor table, plus a correction
for duct length and bends = 1.41 from th Coefficient
of bends table.
This gives 880 × 0.7 × 1.41 = 868.6 cm
2
(134.6
sq.in). This corresponds to a duct diameter of 327
mm (12.9") for each inlet and outlet.
4 Extraction fan capacities: 0.07 × 533 (kW) = 36
m
3/
min (1271 ft
3
/min).
5 Multiply each sum by the number of engines to cal-
culate the area and fan capacity for a common
engine compartment.
Arrangement and Planning, Engine Room
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