Diesel generator set maintenance training diesel article -p161-p165 6135...

Diesel generator set maintenance training diesel engine -p161-p165 6135 diesel engine troubleshooting examples

Third, the diesel generator set 6135 diesel engine troubleshooting examples

Fault 1: diesel generator diesel engine in order to connect the battery line before starting, set well, in the connection "-" polar terminal fire phenomenon occurs when the failure analysis:

It is connected to the “—” pole of the battery or the grounding of the control element.

Remedy: First connect the "?" pole terminal and solid This fault is usually due to the start control line

1 When troubleshooting such failures, first of all, it is necessary to observe whether the start button, the outside of the electric lock, and the external Wiring of the current meter in the control circuit have an external ground iron phenomenon. If there is no external grounding, use a multimeter to block (RX1) and check if there is a short circuit inside the start button. If there is no short circuit, check the next step.

2 Use a multimeter to block (R×1) to check whether there is a short circuit inside the magnetic switch, as shown in Figure 5-9.

Under normal circumstances, the resistance value should be infinite. If the resistance value is very small, it indicates that there is a short circuit inside the magnetic switch. This kind of fault is generally caused by the internal movement of the movable contact and the static contact of the magnetic switch.

2 When removing the magnetic switch, first use the electric iron to open the two solder joints outside the magnetic switch (see Figure 2-111), then remove the fixing bolts , and then use the fine sandpaper to move the contacts (copper plates) to the stationary contacts. The damaged parts are polished. After assembly and welding, it is installed on the starter and connected to the negative pole of the battery again. The fault can be eliminated.

Therefore, Chen 2: When the diesel generator set diesel engine is in operation, it is found that water is sprayed at the water filling point of the water tank. At the same time, the failure of the water in the oil pan is also analyzed:

This fault is generally caused by cracks or blisters around the striated chamber of the cylinder head or cylinder liner. When the piston moves toward the bottom dead center, the in-cylinder pressure decreases, and the cooling water around the cylinder head or cylinder liner enters the cylinder through cracks or trachoma. In addition, water flows into the oil pan through the gap between the cylinder liner and the piston. When the piston moves to the top dead center, the high-pressure gas enters into the water Channel through the crack or trachoma to make the cooling water reverse circulation, causing the tank water inlet to spray water.

Method of exclusion:

1 Remove the side cover of the diesel engine body, and then flash the cylinder liner with a flashlight to determine which cylinder liner the cooling water enters into the oil pan. After finding the faulty cylinder, observe whether the cooling water flows into the oil pan from the cylinder sleeve outer wall or from the inner wall, and remove the corresponding cylinder head of the cylinder. The purpose of doing so is to shorten the troubleshooting time and narrow the fault.

2 Remove the cylinder head cover and rocker assembly in sequence, as shown in Figure 3-15 and Figure 3-16.

2 Disassemble the cylinder head from the outside to the inside diagonally with a torque wrench, as shown in Figure 2-13.

4 Perform hydrostatic test on the removed cylinder head (see news 2-11) to find the fault location. If the cylinder head has blisters or cracks, replace it with a new cylinder head of the same type: If the cylinder head is not damaged, check the next step.

6 Remove the connecting rod bolt of the faulty cylinder with a torque wrench, as shown in Figure 3-19.

6 After removing the piston rod assembly, inspect the cylinder liner for contact with the cooling water for cracks or trachoma.

7 Remove the cylinder liner with a simple cylinder sleeve tensioner (as shown in Figure 2-20). The damaged cylinder sleeve is usually replaced with a new cylinder liner of the same type without repair.

Fault 3: After diesel generator set diesel engine starts, exhaust pipe discharges a lot of black smoke

Failure analysis:

Caused by diesel engine after starting.

Method of exclusion:

The failure of the exhaust pipe to discharge a large amount of black smoke is generally due to the failure of the fuel supply system. The basic method for troubleshooting the fuel supply system is to start the diesel engine first and check the working conditions of each cylinder of the diesel engine after starting. There are two inspection methods: First, touch the die exhaust pipe of diesel engine cylinders to feel the temperature by hand. The purpose is to check whether the working efficiency of each cylinder is consistent. Second, determine the cylinders by using the method of single cylinder oil cut. working condition.

1 After the diesel engine is started, disconnect the high-pressure fuel pipes of the corresponding cylinders of the high-specific oil pump, as shown in Figure 2-27.

If the failure of the black smoke of the exhaust pipe disappears after the oil is cut off by a cylinder or more cylinders, it indicates that these cylinders are not working properly.

2 After removing the stencil, connect the injector to the high-pressure fuel pipe, as shown in Figure 5-12. When starting the diesel engine, if there is a phenomenon of oil dripping or oleophobicity in the fuel injector of the fuel injector, replace the new fuel injector with the same model and trouble can be eliminated.

2 If the failure of the black exhaust smoke of the exhaust pipe disappears after the single-cylinder oil shut-off method is used, it means that the fault is a whole or a global problem. Check whether the fuel injection advance angle is too small or if the air filter is too small. Whether the filter element is dirty or if the pressure in the cylinder is insufficient.

Fault 4: Diesel generator set diesel engine is running, found exhaust pipe black smoke and black oil performance failure analysis:

After the diesel engine was started to the rated speed for a period of time, the black smoke emitted from the exhaust pipe and the overflow of the black oil ribs from the exhaust pipe was a result of incomplete combustion of the diesel fuel in the combustion chamber. The specific reasons are as follows: the oil supply of the sub-pump plungers in the high-pressure oil pump exceeds the standard; the advance angle of the diesel fuel supply is too small: the diesel engine has a large power and the load consumption power is too small s The injector nozzle has a phenomenon of oil splashing.

Method of exclusion:

1 Check the output power of the diesel engine and the power consumption of the load. If the diesel engine power is large and the power consumption of the load is too small, it will cause the exhaust pipe to run black and accompanied by a black oil droplet overflow, which is generally normal. If the power ratio is relatively high and the above fault occurs, check whether the diesel engine's sleeve advance angle has changed.

2 Disassemble the high pressure tubing of the first cylinder of the high pressure pump, as shown in Figure 4-1.

2 Place the speed control handle in the maximum position of the parking space, as shown in Figure 4-2.

4 Use a large flat-blade screwdriver to turn the flywheel in the direction of rotation of the diesel engine. When the oil level of the first cylinder just fluctuates, stop rotating the diesel flywheel. If the oil supply angle is found to be too small, adjustments should be made.

5 If the fuel supply advance angle is correct, remove the F high-pressure oil pump assembly and assemble it on the test bench to check the oil supply of the high-pressure oil pump backup pump. Under normal circumstances, when the 135 series diesel slopping pump (B-type pump plug diameter is kM) is operated at a constant speed of 7506/m blood, the sub-pump injection volume is 25mU 200 times. If the sub-pump is sprayed for a long time, the diesel injected into the combustion chamber by the injector will not be fully burned in the cylinder, resulting in a large amount of carbon and exhaust gas [exhaust, causing the exhaust pipe to emit black smoke and accompanied by black oil droplets. .

Fault 5: Diesel generator set diesel engine start, the starter is running weak, the diesel engine flywheel can only turn half the graph can make the starter drive the diesel flywheel to achieve the minimum starting speed of the diesel engine Fault analysis:

This failure is generally due to the exclusion of battery power caused by:

1 Remove the diesel engine cylinder cover, as shown in Figure 3-15.

2 Use two flat-blade screwdrivers to insert between the rocker arms of the two cylinders and the top of the valve respectively to start the decompression of the diesel engine, as shown in Figure 4-10. Under normal conditions, the diesel engine can start after decompression. If the diesel engine does not start after decompression, replace the fully-charged battery or use three batteries for starting.

Fault 6: After replacing the diesel generator set diesel engine with the new sT614 starter, when starting, the starter does not work. Fault analysis:

This failure is generally due to bad start line contact

It is caused by poor contact or insufficient battery power.

Method of exclusion:

1 Check the start line. Observe the wiring of the electric key and start button for any faults such as open circuit or poor contact.

If the starting line works well, check the starting insurance again.

2 Use a multimeter to block (R×1) the measurement start fuse, as shown in Figure 54. If the starter insurance is not burned out, it should be further checked.

2 Insert a flat-blade screwdriver between the magnetic switch terminal and the lightning battery terminal and then perform the overlap, as shown in Figure 2-118. After lap joint, if the magnetic switch pulls in and the starter operates normally, it indicates that the battery is fully charged and the fault may be on the control line.

Fault 7: After starting the diesel engine

Failure analysis:

After the start button of the diesel engine is released, the starter motor is not disconnected. When the starter continues to rotate, the earthing switch shall be immediately disconnected and the machine shall be shut down immediately. The starter or the thrower Wheel will be burnt and the diesel K wheel will be driven to rotate at a speed. Damage, but also lead to a large number of battery discharge and damage. This kind of failure is generally caused by the starting circuit being out of control or the starter being assembled and adjusted incorrectly.

Method of exclusion:

1 For newly assembled starters, first check that the magnetic switch wiring is correct. Under normal circumstances, the relatively thin wire is connected to the magnetic switch terminal, and the thicker wire is connected to the battery terminal. If the line is connected incorrectly, after the diesel engine is started, the electricity generated by the silicon rectifier alternator enters the switch terminal via the charging current meter, so that the starter is in the circuit closed state.

2 Use a multimeter to block (R×100) the resistance between the magnetic switch terminal and the battery terminal. Under normal circumstances, before the diesel engine has not started, the resistance between the two terminals should be infinite. If the resistance value between the two terminals is very small, it means that the movable contact and the static contact inside the magnetic switch are sintered together. After dismantling, polish the contacts with the fine abrasive paper and the static contacts. The fault can be eliminated after assembly.

7 Use a multimeter to block the start button (RX1), as shown in Figure 5-25. If the internal contacts of the start button are sintered together, the starting circuit will be out of control.