WÄRTSILÄ WARTSILA 50DF, Product Manual

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The fresh water cooling system is divided into a high temperature (HT) and a low temperature
(LT) circuit. The HT water circulates through cylinder jackets, cylinder heads and the 1st stage
of the charge air cooler. The HT water passes through the cylinder jackets before it enters the
HT-stage of the charge air cooler. The LT water cools the 2nd stage of the charge air cooler
and the lubricating oil. The lubricating oil cooler is external. A two-stage charge air cooler
enables more efficient heat recovery and heating of cold combustion air.
In the HT circuit the temperature control is based on the water temperature after the engine,
while the charge air temperature is maintained on a constant level with the arrangement of
the LT circuit. The LT water partially bypasses the charge air cooler depending on the operating
condition to maintain a constant air temperature after the cooler.
9.2.3 Engine driven circulating pumps
The LT and HT cooling water pumps are engine driven. The engine driven pumps are located
at the free end of the engine.
Pump curves for engine driven pumps are shown in the diagrams. The nominal pressure and
capacity can be found in the chapter Technical data.
Fig 9-4 Wärtsilä 50DF 500 rpm V-
engine HT and LT cooling
water pump curves
(4V19L0333A)
Fig 9-3 Wärtsilä 50DF 500 rpm in-
line engine HT and LT cool-
ing water pump curves
(4V19L0332A)
9-4 Wärtsilä 50DF Product Guide - a16 - 9 September 2016
Wärtsilä 50DF Product Guide 9. Cooling Water System