The reasons why the diesel generator cannot start or is difficult to start:
? (1) Fault phenomenon
① There is no explosion sound in the cylinder, and white smoke is emitted from the exhaust. exhaust pipe;
②. Black smoke comes out of the exhaust pipe.
Practice has proven that to ensure the smooth start of the diesel generator, the following four necessary conditions must be met: a. He must have some speed. b. smooth ; C. The cylinder must be well compressed;d. From the above prerequisites for starting a diesel generator, we can deduce the reasons why the diesel generator cannot start or is difficult to start.
(2). Reasons for failure
①. Diesel engine speed is low; has. The starting speed is too low. b. correct position, then incorrectly adjusted; c. The valve has an incorrect gap adjustment.
②.Oil and gas pipes are not smooth; has. There is no oil in the fuel tank, the oil pipeline is blocked, the fuel filter element is blocked, and the oil switch is not turned on. ; b. When the diesel engine starts, the ambient temperature is too low; c. There is moisture or air in the oil circuit; d. The air filter element is poorly atomized; clogged or dirty.
③. Cylinder compression is not good; has. The matching gap between the piston and the cylinder wall is too large; b. The piston ring is broken or the elasticity is too small; the exhaust valves are not closed properly
④. Poor fuel supply; has. The fuel injection time is too early (it is easy to block the fuel injection pump) or too late; on time.
(3) Inspection method? Before inspection, you should carefully observe the fault phenomenon, see the essence through the fault and compress it gradually to achieve the troubleshooting goal. For diesel engine generator starting failure or starting difficulty, it is usually judged and verified based on several different fault phenomena.
①. Diesel engine speed is too low. For diesel engines using electric start, if the starting speed is extremely slow, this fault is mainly due to the inability of the starter, which does not mean that the diesel engine itself is faulty. You need to check the starting circuit to determine if. the battery has enough power and the wires are tight. Check if the starter (starter) is working well and if the air filter is blocked.
②. The starting speed is normal, but it cannot catch fire. There is no explosion sound coming from the cylinder, or there is an intermittent explosion sound and white smoke coming out.t of the exhaust pipe. Through this phenomenon, it means that the diesel is not burned in the body and turns into vapor and is discharged, or there is too much water in the diesel.
First check whether the ambient temperature when starting the diesel generator is too low, then check whether there is air or moisture in the oil circuit. The oil pipe joints of the diesel engine power system are not fixed well, the fuel injector needle is stuck, and the diesel in the fuel tank has been exhausted before shutdown, etc., which can cause air to enter the diesel engine's fuel system. In this way, when the fuel injector piston is inserted when the oil is filled, the air entering the oil circuit is compressed and the oil pressure cannot increase when the fuel injector piston injector is filled. oil, the air volume expands and affects the suction of the oil. In cAs a result, the oil supply volume suddenly increases and sometimes decreases. The inspection method for such defects is to loosen the diesel filter bleed screw, fuel injection pump dropout screw or fuel injection pump high pressure oil pipe, and running the diesel engine. If there are bubbles emerging, it means there is air in the diesel engine's fuel system. The solution is to tighten the oil line seals, then loosen the fuel injection pump dropout screw, rotate the crankshaft until there is none left. Bubbles in the oil, then squeeze. Turn on the machine after deflating the screws. If moisture is detected in diesel, you can also check it with the same method, check the reason for moisture in diesel and replace the diesel in the fuel tank if necessary.
If there is no melange of air and humidity in diesel, you should continue to check whether the injector performance is good and whether the fuel supply and gas delivery time are appropriate.
③. The cranking speed is normal and the cylinder compression is good, but there is no fire or smoke. This is mainly because the low pressure oil circuit is not supplying oil at this time. mainly follows the oil circuit, fuel tank and diesel filter, oil transfer pump and fuel injection pump, etc., the fault location can usually be found.
Poor diesel filtration or not replacing the diesel filter regularly are the main causes of low pressure oil lines and diesel filters. To determine if the oil lines or diesel filters are clogged, you can connect the diesel filter. to the injection pumpfuel. Remove the oil pipe. If there is a lot of oil in the tank but a lot or no oil is flowing out of the diesel filter, it means the diesel filter is clogged. If the low pressure oil circuit provides good oil, the reason why the diesel engine without high pressure oil is mainly because the piston coupling of the fuel injection pump is worn or poorly assembled.
④. The starting speed is normal and the sound of fuel injection can be heard, but it cannot start. This is mainly due to poor cylinder compression.
For a diesel engine equipped with a decompression mechanism, if the decompression mechanism is in the non-decompression position and you can still rotate the diesel engine gently with a crank and feel little resistance , you can conclude that the cylinder is leaking.
After a leak from the intake valve ore exhaust valve, the cylinder compression temperature and pressure are not high, and the diesel is not easy to burn. The main reason for this type of leak is valve clearance. is too small. The valve is not closed properly. On the other hand, if there are carbon deposits and other debris on the bee cone or valve seat, the valve will not close tightly. During the inspection, you can rotate the crankshaft. If you hear a "squealing" sound from the air filter and exhaust pipe, it means there is an air leak in the cylinder.
When rotating the crankshaft, if there is a sound of air leaking at the joint surface of the cylinder head and cylinder block, it means that there is a air leak in cylinder seal. The cylinder head nut may not be tightened or loose, or the cylinder gasket may be broken.
When rotating the crankshaft, the noise of a leakAir is heard inside the engine body or at the oil filler port. The cause lies mainly in the piston ring. In order to know if the pressure is insufficient in the piston ring. The cylinder is caused by a bad piston ring. You can add a small amount of lubricating oil into the cylinder. If the compression force in the cylinder increases obviously after adding engine oil, it means that the piston is excessively worn, causing a corresponding gap between the two. the cylinder and piston ring are too large and air is trapped between the piston ring and cylinder liner. There is a leak in the crankcase.
If the compression force does not change much after adding engine oil, it indicates that the insufficient compression force in the cylinder has nothing to do with the piston. Air may be escaping through the intake valve or exhaust.catchment. valve.