Man B&W S50ME-B9.3-TII User Manual

MAN B&W 6.04
Page 11 of 12
MAN Diesel
MAN B&W S50ME-B9.3\-TII 198 90 85-7.0
Calculation of Exhaust Data for Derated Engine
Example 3:
Expected exhaust gas data for a derated 6S50ME-B9.3-TII with 1 high efficiency MAN TCA55-26
turbocharger , high load and fixed pitch propeller.
Based on the engine ratings below, and by means of an example, this chapter will show how to calculate
the expected exhaust gas amount and temperature at service rating, and for a given ambient reference
condition different from ISO.
The calculation is made for the service rating (S) of the diesel engine being 80% of the specified MCR.
Nominal MCR, (L
1
) P
L1
: 10,680 kW (100.0%) and 117.0 r/min (100.0%)
Specified MCR, (M) P
M
: 9,612 kW (90.0%) and 111.2 r/min (95.0%)
Service rating, (S) P
S
: 7,689 kW and 103.2 r/min, P
S
= 80.0% of P
M
Reference conditions
Air temperature T
air
.............................................................. 20° C
Scavenge air coolant temperature T
CW
............................... 18° C
Barometric pressure p
bar
...................................................... 1,013 mbar
Exhaust gas backpressure at specified MCR ∆p
M
............ 300 mm WC
a) Correction for choice of specified MCR point M:
P
M%
=
9,612
_____
10,680
x 100 = 90.0%
n
M%
=
111. 2
____
117.0
x 100 = 95.0%
By means of Figs. 6.04.07 and 6.04.08:
∆m
M%
= -0.25%
∆T
M
= -3.9 °C
b) Correction for ambient conditions and
backpressure:
By means of equations [7] and [8]:
∆M
amb%
=  0.41 x (20  25) + 0.03 x (1,013  1,000)
+ 0.19 x (18  25)  0.011 x (300  300)%
∆M
amb%
= + 1.11%
∆T
amb
= 1.6 x (20  25)  0.01 x (1,013  1,000)
+ 0.1 x (18  25) + 0.05 x (300  300) °C
∆T
amb
=  8.8 °C
c) Correction for the engine load:
Service rating = 80% of specified MCR power
By means of Figs. 6.04.11 and 6.04.12:
∆m
S%
= + 7.1%
∆T
S
=  18.8 °C

Man B&W S50ME-B9.3-TII Specifications

General

Brand	Man
Model	B&W S50ME-B9.3-TII
Category	Engine
Language	English