1) Safety tolerance 5%
Safety tolerance 5% is subtracted from fuel con-
sumption
2) Correction for ambient (β-calculation)
In accordance to ISO-Standard ISO 3046-1:2002
“Reciprocating internal combustion engines – Per-
formance, Part 1: Declarations of power, fuel and
lubricating oil consumptions, and test methods –
Additional requirements for engines for general use”
MAN Diesel & Turbo specifies the method for recal-
culation of fuel consumption dependent on ambient
conditions for 1-stage turbocharged engines as
follows:
The formula is valid within the following limits:
+ Ambient air temperature 5°C – 55°C
+ Charge air temperature before
cylinder
25°C – 75°C
+ Ambient air pressure 0.885 bar – 1.030
bar
β Fuel consumption factor
t
bar
Engine type specific reference charge air tempera-
ture before cylinder,
see »Reference conditions« in
»Fuel oil consump-
tion for emissions standard«.
Legend
Ref-
erenc
e
Site/FAT
Specific fuel consumption [g/
kWh]
b
r
b
x
Ambient air temperature [°C] t
r
t
x
Charge air temperature
before cylinder
[°C] t
bar
t
bax
Ambient air pressure [bar] p
r
p
x
Example
Reference values:
br = 200 g/kWh, tr = 25°C, tbar = 40°C, pr = 1.0
bar
At site:
t
x
= 45°C, t
bax
= 50°C, p
x
= 0.9 bar
ß = 1+ 0.0006 (45 – 25) + 0.0004 (50 – 40) + 0.07
(1.0 – 0.9) = 1.023
b
x
= ß x b
r
= 1.023 x 200 = 204.6 g/kWh
3) Correction for lower calorific value
(LCV)
Whenever LCV value rise 427 kJ/kg the SFOC will
be reduced with 1%
4) Correction for engine mounted pumps
MAN Diesel & Turbo
3700405-6.2
Page 3 (4)
Calculation of specific fuel oil consumption (SFOC)
B1101 0
V28/32S-DF, L28/32S-DF, L28/32DF, L23/30S-DF, L23/30DF, V28/32S, L28/32S,
L27/38S, L23/30S, L21/31S, L16/24S, L16/24, L21/31, L23/30H, L27/38, L28/32H
To Next Page
Loading...
Need help?
General
