Detection method for cracks in the casing of diesel generator sets

Diesel generator sets are widely used in mines, railways, field construction sites, road traffic maintenance, as well as factories, enterprises, hospitals and other departments because of their stable performance, strong reliability, ease of movement, and convenient maintenance. However, due to various reasons, after the diesel generator set is used for a long time, there may be shell cracks. After checking the crack position, it should be repaired in time according to the size of the crack. If the crack is too large, it is recommended to contact the generator manufacturer directly. repair.

       Diesel generator sets are widely used in mines, railways, field construction sites, road traffic maintenance, as well as factories, enterprises, hospitals and other departments because of their stable performance, strong reliability, ease of movement, and convenient maintenance. However, due to various reasons, after the diesel generator set is used for a long time, there may be shell cracks. The main reasons are the following two points:

       1. Manufacturing defects

       Diesel generator set shells are usually cast parts. During the casting process, it is inevitable that some pores, blisters or cracks due to stress will occur. In the later use process, these manufacturing defects will gradually enlarge and eventually lead to leakage and are found;

       2. Reasons for use and maintenance

       When the diesel generator set is running in winter, antifreeze should be added to the cooling circulating water or the cooling water should be drained in time when it is stopped. Once the cooling water freezes during shutdown, it will be extremely easy to cause the shell to be frozen and cracked, resulting in water seepage and unusable use;

       When it is judged that there is a crack in the casing of the diesel generator set, the user should check the specific location of the crack in time, as follows:

       1. Check the position of the crack by observation method

       When the diesel generator set is in use, if it is found that there is lubricating oil overflowing from the inspection scale of the oil pan, the electricity user should be notified immediately, and then the machine should be stopped for inspection. This kind of failure is generally caused by coolant or diesel entering the oil pan.

       After the diesel generator set is stopped, the cover plate of the observation window of the body should be quickly removed, and then the inner wall of the body should be irradiated with a flashlight to observe whether the water leakage occurs on the inner wall of the body or the outer wall or inner wall of the cylinder liner.

       If it is found that coolant seeps out from the inner wall of the engine, it means that there is a crack in the inner wall of the diesel engine; if it is found that the inner wall of the cylinder liner has cooling droplets into the oil pan, it is mostly due to the deformation or damage of the diesel engine body, cylinder head or cylinder gasket. It may be that the cylinder liner has blisters; if the outer wall of the diesel engine cylinder liner has cooling droplets or seepage, it is generally caused by the damage to the sealing ring of the outer wall of the cylinder liner. If no water leakage is found on the inner wall of the body, the inner wall or the outer wall of the cylinder liner, it can generally be concluded that the fault is caused by the damage of the water-cooled lubricating oil cooler or the entry of diesel oil into the oil pan.

       2. Check the crack of the body by the hydraulic test method

       Detect the position of the crack in the body by the hydraulic test method, install the cylinder head and the cylinder head gasket on the body, install the cover plate on the position where the water pump is installed in the body, connect the water pipe with the hydraulic press, and seal all the other water channels, and then press the water The machine presses water into the body. It is also possible to pass tap water with a certain pressure into the body for testing.

       When checking the position of the body crack by the hydraulic test method, the water entering the body must be kept under a certain pressure for a period of time. Usually, the water pressure should be kept at 0.3~0.4MPa, and there should be no leakage after 10 minutes. . If there is no hydraulic press, you can also add tap water to the water jacket first, and then use an air pump or high-pressure air cylinder to inflate the water jacket filled with water, and check the leakage site by the pressure of the gas.