Bergen B35:40, Project Manual

Page: 45 / 74

, Gas
Page 1 : 6
2.06
1011 BC
C
OOLING WATER SYSTEMS
Introduction
The cooling water system is divided into 2 main
systems, Low temperature and High temperature.
LT: Low temperature freshwater cooling water
system, is cooling the low temperature stage of the
charge air cooler (52LT), the lubricating oil cooler
(50LO), the generator cooler (56LT) and the
HT - system.
Auxiliary engines and other general equipment may
also be cooled by the LT – system, but (preferably)
supplied by separate electrical pumps. As an option
box-coolers can be used as central coolers.
The LT - system is cooled by sea water.
HT:
High temperature freshwater cooling water
system is cooling the high temperature stage of the
charge air cooler (52HT) and the cylinder block. HT
cooling water is also known as jacket cooling water.
The heat surplus from the HT cooling water, might be
utilized in a heat recovery system.
Pumps and capacities
Engine driven or electrically driven centrifugal
pumps are to be used depending on the system lay-
out. Normal pressure rise over engine driven pumps
is 3.0-3.5 bar, depending on what the required water
flow is and the corresponding pump curve.
In order to avoid salt incrustation in the sea water
piping system,the sea water temperature after last
cooler should not exceed:....................................48 °C.
See Technical Data in part 1 for pump capacities,
temperatures and required heat dissipation.
Options
Electrical LT-pump
The built on engine driven LT-pump can be replaced
by an electrical driven LT-pump. The normal set-up is
one el. driven main pump and one standby pump
per cooling water system.
LT stand by pump
As a stand by for the built on mechanical low temp
cooling water pump on the engine an electrical driv-
en stand by pump can be supplied. It can be started
by a pressure sensor on the engine. This solution is
normally used on single engine applications.
HT stand by pump
For the built on mechanical high temp cooling water
pump on the engine there is a loose supplied electri-
cal stand by pump. It can be started by a pressure
sensor on the engine. This solution is normally used
on single engine applications.
Jacket water heater module
A jacket water heater module (90HT), with
electrically driven circulating pump and electric
heater, can be supplied for the purpose of keeping
the engine warm in standby duty.
The heater module circulating pump has a capacity
of:............................................................................ 3.0 m
3
/h
with electric motor of rating:............................ 0.5 kW
The heater module electric heater
has a rating of: ........................................................ 18 kW
Expansion tank and system venting
For satisfactory operation of the cooling water
system and preventing cavitation of the water pump,
the jacket water system and the closed part of the
integrated cooling system must be equipped with an
adequate deaeration. For this purpose a vent pipe,
from the highest point of the system, to an expan-
sion tank is required.
The pipe should be connected to the bottom of the
tank as far as possible from the expansion tank
header pipe.
The vent pipe connection to the system should be
equipped with some sort of device able to collect the
air, for example a saddel fitting (72LT).
The header pipe should be connected as close as
possible to the suction side of the water pump.
The expansion tank should also be arranged to make
it possible to insert water treatment agents into the
cooling water.
Observe that the expansion tank should be located
with its bottom min. 3 meters and max. 10 meters
above top of engine. On request the expansion tank
can be located as much as 20 meters above top of
engine.