With the development of society and the advancement of science and technology, the use of diesel generator sets is becoming more and more widespread. In the process of use, everyone finds that diesel generator sets will always have various problems. In view of these common faults, how to solve them is more appropriate. Let us take a look at common faults and solutions of diesel generators.
1 Difficult to start
1.1 Failure phenomenon
Driven by the starter, the diesel generator's speed reaches the starting speed, but it cannot start, which usually manifests itself as:
(1) There is no explosion sound when starting, and the exhaust port is discharged without smoke, so it cannot be started.
(2) Continuous burst sounds can be heard at startup, with white smoke or a small amount of black smoke, but cannot be started.
1.2 Cause of failure
(1) Failure of low-pressure oil circuit
1) There is no oil in the fuel tank or the oil level is too low.
2) The oil pipe is broken, and the oil pipe joint is loose and leaking.
3) There is no air or piping in the fuel supply system, causing the engine to catch fire.
4) There is water in the diesel oil, which freezes in winter, which causes the pipeline to be blocked; the diesel used in winter does not match the label, which causes the diesel to wax out and block the filter and the oil pipe.
5) Do not clean for a long time, do not replace the diesel filter element, causing blockage.
6) The fuel injection pump overflow valve spring is broken or cushioned by foreign matter, so that the diesel oil flows from the low-pressure oil circuit back to the diesel tank, so that the low-pressure oil circuit cannot maintain a certain oil pressure and the engine does not catch fire.
(2) Oil pump failure
1) The check valve is improperly assembled or used for too long, causing the valve seat surface to wear out too much.
2) The filter is clogged.
3) The oil pump's plunger bites, or the spring is broken, or the wear is severe, and the oil pump cannot supply oil properly.
4) The oil pump push rod is bitten.
5) The hand oil pump piston is not tightly sealed.
(3) Failure of oil supply drive train
1) The governor transmission rods are worn out so that the oil supply rack rod cannot reach the position of the starting oil quantity and the rated oil quantity.
2) The oil stop cylinder is stuck at a low oil level, and the engine cannot catch fire, or the connection part of the oil stop cylinder comes off.
3) The connecting rod of the joystick is severely worn and cannot control.
(4) Failure of the fuel injection pump
1) Adjust the gear rod to bite to death, or the plunger will be stuck due to the broken spring, so that the oil supply gear rod always stays in the parking position.
2) The plunger is too worn, or the plunger is stuck in the sleeve.
3) Gear wear is severe, causing the gap between the plunger and the tappet to be too large, causing the amount of pump oil to drop and causing the engine to catch fire.
4) The locking bolt of the oil supply adjustment ring gear is loosened or falls off, which changes the oil supply of the pump.
5) There is dirt on the oil outlet valve, or the oil outlet valve spring breaks and leaks oil, or a valve issues a card.
6) The coupling plate of the fuel injection pump is damaged, or the coupling bolts are loose, which changes the fuel supply time and causes the engine to catch fire.
7) The connection between the transmission shaft and the transmission gear of the fuel injection pump is loose, causing the fuel injection pump not to work.
8) The intermediate timing gear or fuel injection pump transmission gear is broken.
(5) Failure of the injector
1) The high pressure oil pump joint is loose or the high pressure oil pipe is broken.
2) The fuel injection nozzle is blocked or the fuel injection needle valve is stuck due to overheating.
3) Fuel injection nozzles are severely worn, leak oil, and have poor atomization.
4) The spray pressure of the fuel nozzle changes. The pressure is too low to burn.
5) The fuel injection nozzle is damaged.
6) The gasket is not sealed and leaks air.
1.3 Fault judgment and elimination
(1) First check the oil level of the fuel tank. If there is no oil or the oil level is too low, fill it up. After the oil level is full, supply oil with a hand oil pump, and open the bleed plug on the diesel filter, check whether there is air in the oil circuit, and drain it if necessary. If the air exhaust is not clean, check the tubing joints for looseness and cracked tubing. During the inspection, wipe the joint and the place where the pipeline is suspected to be broken with a clean towel, and then observe by pumping oil with a hand oil pump. If diesel oil appears again, the place is loose or broken.
(2) Pump oil with a hand oil pump. If the oil does not come smoothly, it means that there is a blockage in the low-pressure oil circuit. Check the oil-water separator (primary filter), diesel filter and pipeline. Special emphasis is to check whether the metal filter element in the oil-water separator is blocked.
(3) Pump oil with a hand oil pump and open the screw plug on the diesel filter to check whether there is water droplets in the diesel oil. If there are water droplets, release the oil and water from the fuel tank and re-qualify the diesel oil.
(4) When pumping oil with a hand oil pump, I feel that there is no pumping force and the oil does not come out for many times, that is, the piston of the hand oil pump is worn too much, or the valve is contaminated, or the wear is severe and the seal is not tight. The hand oil pump should be repaired or replaced. If you feel elasticity and resistance when pumping oil, it will be very painful when the handle is pressed down, and the handle will automatically return when you release the handle, indicating that the oil pump's inlet pipe to the fuel tank is blocked. At this point, the oil tank to the oil-water separator and the oil pump pipeline are all replaced with transparent pressure-resistant plastic pipes, and the oil flow and blockage can be seen very clearly. In addition, poor sealing of the hand oil pump cover can also cause poor oil pumping.
(5) After the above inspection, if everything is normal, check the operation of the fuel injection pump, check whether the transmission gear is loose and damaged, whether the fuel injection advance angle is changed, and whether the coupling fixing bolts are loose. If the engine's fuel injection pump shaft rotates, the high pressure fuel pipe connector of the fuel pump should be disassembled, drive the engine with the starter, and increase the throttle. If there is no oil flowing out of the fuel pipe connector of the fuel pump, check and verify the fuel pump. The inspection of the fuel injection pump should be carried out on the fuel pump test bench and adjusted according to the standard.
If after the fuel injection pump calibration, the fuel injection advance angle is all normal and still cannot start, the fuel injector should be disassembled to check the fuel injection pressure and nozzle atomization. If the atomization is not good, it will also cause the engine to start difficult.
Be sure to replace the diesel that meets the standards according to the season to prevent diesel wax out.
2 Rough work
2.1 Failure phenomenon
The engine was unstable, and a metal-like knocking sound was produced along with the black smoke from the exhaust pipe. The tapping sound intensified during acceleration, the tapping sound weakened or disappeared at high speed, and the tapping sound was reproduced at idle.
2.2 Cause of failure
(1) Due to the loosening of the fixing bolt of the fuel injection pump coupling, the advance angle is too large.
(2) The fuel quality is poor or the fuel supply of each cylinder is uneven, and the fuel supply of individual cylinders is too large.
(3) Long-term high-speed operation, engine temperature is too high or deflagration occurs.
(4) Severe carbon accumulation in the combustion chamber can also cause deflagration.
Adjust the fuel advance angle in time and use the correct fuel.