Man L23/30DF, Руководство по проекту

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Specification of engine coolant
Preliminary remarks
An engine coolant is composed as follows: water for heat removal and cool-
ant additive for corrosion protection.
As is also the case with the fuel and lubricating oil, the engine coolant must
be carefully selected, handled and checked. If this is not the case, corrosion,
erosion and cavitation may occur at the walls of the cooling system in con-
tact with water and deposits may form. Deposits obstruct the transfer of heat
and can cause thermal overloading of the cooled parts. The system must be
treated with an anticorrosive agent before bringing it into operation for the
first time. The concentrations prescribed by the engine manufacturer must
always be observed during subsequent operation. The above especially
applies if a chemical additive is added.
Requirements
The properties of untreated coolant must correspond to the following limit
values:
Properties/Characteristic Properties Unit
Water type Distillate or fresh water, free of foreign mat-
ter.
–
Total hardness max. 10 dGH
1)
pH value 6.5 – 8 –
Chloride ion content max. 50 mg/l 2)
Table 1: Properties of coolant that must be complied with
1)
1 dGH (German
hardness)
≙
10 mg CaO in litre of water
≙
17.9 mg CaCO
3
/l
≙
0.357 mval/l
≙
0.179 mmol/l
2) 1 mg/l
≙
1 ppm
The MAN Diesel & Turbo water testing equipment incorporates devices that
determine the water properties directly related to the above. The manufactur-
ers of anticorrosive agents also supply user-friendly testing equipment.
Notes for cooling water check see 010.005 Engine – Work Instructions
010.000.002-03
Additional information
If distilled water (from a fresh water generator, for example) or fully desalina-
ted water (from ion exchange or reverse osmosis) is available, this should
ideally be used as the engine coolant. These waters are free of lime and
salts, which means that deposits that could interfere with the transfer of heat
to the coolant, and therefore also reduce the cooling effect, cannot form.
However, these waters are more corrosive than normal hard water as the
thin film of lime scale that would otherwise provide temporary corrosion pro-
tection does not form on the walls. This is why distilled water must be han-
dled particularly carefully and the concentration of the additive must be regu-
larly checked.
Limit values
Testing equipment
Distillate
2017-08-18 - de
Specification of engine coolant
D010.000.023-13-0001
General
MAN Diesel & Turbo
010.000.023-13
D010.000.023-13-0001 EN 1 (7)