Gas Engines – Pressure Losses And Flowrates - Kohler SFGLD480 Operation & Maintenance Manual

1. INTRODUCTION
When calculating pressure losses in the cooling circuits of gas engines. Product Information Datasheets
IT-C-A-20-001e and IT-C-A-20-002e apply. The former explains how to calculate pressure losses based on the
components layout. while the latter summarises the pressure losses for each separate component.
To define flowrates in addition to the parameters that guarantee correct performance of the engine against seizing
or knocking. we take it into account that the flowing-through velocity in the heat exchanger pipes should not be
less than 1m/s nor greater than 3m/s.
CAUTION
Maximum flowrate in the main circuit depends on the external cooling system. while the maximum flowrate in
the auxiliary circuit is determined by the passage cross section in the air and oil coolers and should not exceed
3
30m /h.
According to the temperature of the primary and/or secondary cooling circuit(s). the minimum flowrates will vary.
WARNING
The circuit's pressure loss (Delta P) and restriction (K) are valid for a basic engine configuration with mechanical
pumps as defined in section 5 of this document. Any change to the components of said configuration will entail
recalculating both aforementioned parameters. For instance. if the engine incorporates electric pumps. the
thermostat box is different from that specified for engines with mechanical pumps; therefore. you need to
recalculate both the restriction and the pressure loss.
Considerations to take into account in other engine applications or engine configurations

The minimum flowrates specified for both cooling circuits apply to "continuous" duty equipment. For
"standby" units. the minimum flowrate shall be determined. increasing it in the same proportion as power
does in relation to the tabulated flowrates.
Minimum flowrates are the same for engines with dry exhaust manifolds and with (wet) cooled exhaust

manifold.

For variable speed engines the Minimum flows are the same that for constant speed engines
PRODUCT INFORMATION
IT-G-A-20-007e
GAS ENGINES – PRESSURE LOSSES AND FLOWRATES
2.2.9
INDEX DATE
I
May 2015
O&M_2.002211.810_A_10_2016
Dep. 2
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