Adjustment of Diesel Generator Governor Under Load Conditions

We all know that diesel generator sets often encounter sudden increases in load during operation. If the diesel engine is already operating at full load and the fuel supply has reached the maximum, in case of overload, the diesel engine speed will drop rapidly and stall. In addition, the following hazards may occur:

1.Poor sealing between piston and cylinder liner, causing oil to dart into, and exhaust emitting blue smoke;

2.For supercharged diesel engines, due to low load or no load, the supercharging pressure is low, resulting in reduced sealing effect of the supercharger oil seal, and oil dart into the supercharging chamber, entering the cylinder along with the intake air;

3.A part of the oil dart into the cylinder participates in combustion, so oil will gradually accumulate in the cylinder liner exhaust passage, which will also form carbon deposits;

4.When the oil in the supercharger's supercharging chamber accumulates to a certain extent, it will leak from the joint surface of the supercharger;

5. Long-term overload operation will more seriously lead to increased wear of moving parts, deterioration of the engine combustion environment, and other consequences that lead to the advance of the overhaul period.

Therefore, foreign diesel engine manufacturers stipulate that regardless of the operating conditions, the minimum load of the unit's rated power should not be lower than 25% - 30%.

However, in daily use, in order to improve the diesel engine's ability to overcome short-term overload, a correction device is often installed in the full-range governor. So how does this governor adjust under load conditions? Dingbo Diesel Generator will introduce it to you.

This is the situation when there is no correction device. When the diesel engine is overloaded, the speed drops below the rated speed, the axial component Fa of the flying ball centrifugal force is less than the governor spring force F. When the diesel engine is under constant load, the correction spring 8 is in a free state, and there is still a gap between it and the sliding sleeve 7.

This is the situation when the diesel engine is working under rated conditions. The sliding sleeve just starts to contact the correction spring, the gap disappears, and the fuel supply pull rod is in the rated fuel position, which is the situation when the diesel engine is working under overload. Due to the decrease of crankshaft speed, the axial component F of the flying ball centrifugal force decreases. The elastic force F of the governor spring is greater than Fa, forcing the sliding sleeve to move to the left, and the fuel supply pull rod also moves slightly in the direction of increasing fuel supply to overcome the overload. When the sliding sleeve collides with the shoulder of the fuel limit screw, the correction fuel reaches the maximum. The distance that the fuel supply pull rod moves from the start of compression of the correction spring to the collision with the shoulder is called the correction stroke. The maximum correction stroke of the governor is 1.2 - 1.5mm.

Guangxi Dingbo Generator Set Manufacturing Co.,Ltd. was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to [email protected] we will pay highly attention on your question.