WÄRTSILÄ 31SG Product Manual page 83

Required heating power to heat up the engine, see formula below:
where:
P = Preheater output [kW]
T Preheating temperature = 60...70 °C
1 =
T Ambient emperature [°C] m
0 =
V = Lubricating oil volume [m
LO
V = HT water volume [m
FW
t = Preheating time [h]
k Engine specific coefficient = 1 kW n
eng =
9.2.12.2 Circulation pump for HT preheater (4P04)
Design data:
Delivery pressure 80...100 kPa (0.8...1.0 bar)
9.2.12.3 Preheating unit (4N01)
A complete preheating unit can be supplied. The unit comprises:
● Electric or steam heaters
● Circulating pump
● Control cabinet for heaters and pump
● Set of thermometers
● Non-return valve
● Safety valve
9.2.13 Throttles
Throttles (orifices) are to be installed in all by-pass lines to ensure balanced operating conditions
for temperature control valves. Throttles must also be installed wherever it is necessary to
balance the waterflow between alternate flow paths.
9.2.14 Thermometers and pressure gauges
Local thermometers should be installed wherever there is a temperature change, i.e. before and
after heat exchangers etc. in external system.
Local pressure gauges should be installed on the suction and discharge side of each pump.
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= Engine weight [tonne]
eng
] (wet sump engines only)
3
3 ]
Number of cylinders
cyl =