Volvo D11 series, Installation Manual

Page: 174 / 212

Engine room, ventilation and sound proofing
72
Calculation of air ducts, example 1,
two diesel engines, 294 kW (400 hp)
Calculation of areas for
two engines at 294 kW each
with a non-restricted air supply and an ambient air
temperature of +30°C (+86°F).
For each engine the following is obtained:
Area, engine’s air consumption:
.
.9 × 294 = 558 cm² (87 sq.in).
According to figs 1 and 2 on the following page,
ex , this corresponds to a duct with a diameter of
265 mm (0.5") for
one engine.
Area ventilation, engine room:
.
Inlet, engine room: Area = .65 × 294 = 485 cm²
(75 sq.in). According to
fig. 2 this gives a diam-
eter of 250 mm (9.8") for a single
engine.
2.
Outlet, engine room: Area = .65 × 294 = 485
cm² (75 sq.in). According to
fig. 2 this gives a di-
ameter of 250 mm (9.8") for a single engine.
3.
Extraction fan capacity 0.07 × 294 = 20.6 m³/
min (728 ft³/min).
4. NOTE! As this is a twin installation figures have to
be doubled.
Calculation of air ducts, example 2,
diesel engine, 441 kW (600 hp)
Calculation of areas for
one engine with 2 m (6.6 ft)
duct length, 2 bends and an ambient air temperature
of +20°C (+68°F).
Area for engine’s air consumption:
. .9 × 44 = 838 cm² (30 sq.in).
Correction for air temperature = 0.7 from Table 2,
and correction for duct length and bends = .4
from
Table 1.
This gives 838 × 0.7 × .4 = 827 cm² (28 sq.in).
According to fig. 2 this gives a duct diameter of
330 mm (3").
Area ventilation, engine room:
.
Inlet, engine room: Area = .65 × 44 = 728 cm²
(3 sq.in). According to
fig. 2, this gives a duct
diameter of 302 mm (2").
2.
Outlet, engine room: Area = .65 × 44 = 728
cm² (3 sq.in). According to fig. 2 this gives a
duct diameter of 302 mm (2").
3. Correction (inlet and outlet) for air temperature
= 0.7 from Table 2, and correction for duct length
and bends = .4 from Table 1.
This gives 728 × 0.7 × .4 = 79 cm² (2 sq.in).
According to fig. 2 this gives a duct dia of
300 mm (.8") for each inlet and outlet.
4.
Extraction fan capacity 0.07 × 44 = 3 m³/min
(095 ft³/min).