MAN B&W L28/32H, Manual

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08028-0D\H5250\94.08.12
General
This data sheet contains data regarding the necessary
information for dimensioning of auxiliary machinery
in the external cooling water system for the L28/32H
type engine(s).The stated data are for one engine
only and are specified at MCR.
For heat dissipation and pump capacities see D 10
05 0 "List of Capacities". Setpoints and operating
levels for temperature and pressure are stated in B
19 00 0 "Operating Data and Setpoints".
External pipe velocities
For external pipe connections we prescribe the
following maximum water velocties:
Fresh water : 3.0 m/s
Sea water : 3.0 m/s
Pressure drop across engine
The pressure drop across the engines HT system,
exclusive pump and thermostatic valve is approx.
0.5 bar.
Lubricating oil cooler
The pressure drop of cooling water across the built-
on lub. oil cooler is approx. 0.3 bar, the pressure drop
may be different depending on the actual cooler
design.
Thermostatic valve
The pressure drop across the built-on thermostatic
valve is approx. 0.5 bar.
Charge air cooler
The pressure drop of cooling water across the charge
air cooler is:
D
P = V² x K [Bar]
V = Cooling water flow in m³/h
K = Constant
Pumps
The cooling water pumps should be of the centrifugal
type.
FW SW
Differential pressure 1-2.5 bar 1-2.5 bar
Working temperature max.90°C max.50°C
Expansion tank
To provide against changes in volume in the closed
jacket water cooling system caused by changes in
tempera-ture or leakage, an expansion tank must be
installed.
As the expansion tank also provides a certain suction
head for the fresh water pump to prevent cavation,
the lowest water level in the tank should be minimum
5 m above the centerlinie of the crankshaft.
Minimum recommended tank volume: 0.15 m³.
For multiplants the tank volume should be min.:
V = 0.15 + ( exp. vol. per ekstra eng.) [m³]
Data for external preheating system
The capacity of the external preheater should be 1.7-
2.0 Kw/cyl. The flow through the engine should for
each cylinder be approx. 2.2 l/min with flow from top
and downwards and 15 l/min with flow from bottom
and upwards. See also table 1 below.
Design Data for the External Cooling Water System B 13 00 0
99.48
L28/32H
1613545-8.1
Page 1 (1)
Cyl. No.
Quantity of water in eng:
HT-system (litre)
LT-system (litre)
Expansion vol. (litre)
Preheating data:
Radiation area (m²)
Thermal coeff. (KJ/°C)
7
700
97
39
32.1
7644
8
800
101
44
35.7
8736
9
900
105
50
39.3
9828
Table 1 Showing cooling water data which are depending on
cylinder no.
6
600
93
33
28.5
6552
5
500
89
28
24.9
5460