External Gear Pump: Capacity & Pressure Effects

[MickMcC]

TL;DR

What happens if you increase the flow rate and pressure to the suction side of a gear pump on a marine diesel engine?

Hi everyone,

Let's say I have an external gear pump driven by the camshaft of a marine diesel engine. The nominal speed of the engine is 1800 rpm and the capacity of the pump at nominal speed is 8 L/min. Diesel fuel is supplied to the gear pump suction at 0.4 bar g pressure via a 15 mm pipe.

If everything remains the same on the engine side of the pump. What would happen if the fuel is supplied to the pump at 1.3 bar g at 11.5 L/min?

 

[Lnewqban]

Summary:: What happens if you increase the flow rate and pressure to the suction side of a gear pump on a marine diesel engine?

Hi everyone,

Let's say I have an external gear pump driven by the camshaft of a marine diesel engine. The nominal speed of the engine is 1800 rpm and the capacity of the pump at nominal speed is 8 L/min. Diesel fuel is supplied to the gear pump suction at 0.4 bar g pressure via a 15 mm pipe.

If everything remains the same on the engine side of the pump. What would happen if the fuel is supplied to the pump at 1.3 bar g at 11.5 L/min?

Welcome, Mick
The gear pump is of positive displacement type, meaning that flow rate depends only on rpm’s.
For that reason, I believe that the thing will continue delivering 8 L/min after inlet pressure increases from 0.4 to 1.3 bar.