MAN B&W S65ME-C8.2-GI-TII User Manual

MAN B&W 6.04
Page 7 of 12
MAN Diesel
198 88 30-5.1MAN B&W S65ME-C8.2-GI-TII
Calculation of Freshwater Production for Derated Engine
Example 2:
Freshwater production from a derated 6S65ME-C8.2-GI-TII with 1 high efficiency MAN TCA77-21
turbocharger , high load and fixed pitch propeller.
Based on the engine ratings below, this example will show how to calculate the expected available jacket
cooling water heat removed from the diesel engine, together with the corresponding freshwater production
from a freshwater generator.
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
: 17,220 kW (100.0%) and 95.0 r/min (100.0%)
Specified MCR, (M) P
M
: 15,498 kW (90.0%) and 90.3 r/min (95.0%)
Service rating, (S) P
S
: 12,398 kW and 83.8 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 Δp
M
............ 300 mm WC
The expected available jacket cooling water heat at service rating is found as follows:
Q
jw,L1
= 2,490 kW from List of Capacities
Q
jw%
= 92.2% using 90.0% power and 95.0%
speed for M in Fig. 6.04.02
By means of equation [1], and using factor 0.885
for actual ambient condition the heat dissipation
in the SMCR point (M) is found:
Q
jw,M
= Q
jw,L1
x
Q
jw%
___
100
x 0.885
= 2,490 x
92.2
____
100
x 0.885 = 2,032 kW
By means of equation [2], the heat dissipation in
the service point (S) i.e. for 80.0% of specified
MCR power, is found:
k
p
= 0.852 using 80.0% in Fig. 6.04.04
Q
jw
= Q
jw,M
x k
p
= 2,032 x 0.852 = 1,731 kW
-15%/0%
For the service point the corresponding expected
obtainable freshwater production from a freshwa-
ter generator of the single effect vacuum evapora-
tor type is then found from equation [3]:
M
fw
= 0.03 x Q
jw
= 0.03 x 1,731 = 52.0 t/24h
-15%/0%

MAN B&W S65ME-C8.2-GI-TII Specifications

General

Brand	MAN B&W
Model	S65ME-C8.2-GI-TII
Category	Engine
Language	English