Diesel generator set maintenance training diesel article -p146-p150

Diesel generator set maintenance training diesel article -p146-p150

Fault 3: After the diesel generator diesel engine starts, the charging current macro shows that the charging current is too large Fault Analysis:

This kind of fault is generally caused by the defective power of the defective battery or improper adjustment of the voltage regulator spring. The specific reasons are: poor contact of the high-speed contacts inside the regulator; low speed contacts inside the regulator are sintered or cannot be opened: the voltage of the regulator is adjusted. Too high; internal coils or resistors of regulators are open circuited, short-circuited or faulty;

Method of exclusion:

1 If the battery is not depleted or short-circuited, remove the voltage regulator housing and check the operation of the internal coil and contacts. If you find a suspicious point in the middle of inspection, use a u screwdriver to slightly lengthen the spring of the regulator by 0.2~0.3mm.

2 After shutdown, use a multimeter to test the single cell voltage and overall voltage of the battery, as shown in Figure 5-14.

The voltage of each cell of the first cell is required to be equal. If the voltage of the individual cell differs from the specified cell voltage by more than 1V, it indicates that the cell has a failure inside the cell and should be sent to a battery repair shop for repair.

Fault 4: After the start of the diesel generator set diesel engine, the marriage of the exhaust pipe discharge blue-black failure analysis:

This failure is a comprehensive failure. It is generally caused by incomplete combustion of diesel in the combustion chamber and failure to burn some oil after it has entered the combustion air evaporation. The specific causes are: too much oil in the bottom of the oil; piston rings and cylinders Over wear or piston ring is stuck and broken; Valve stem and valve catheter wear gap is too large: Intake and exhaust valve close lax; Individual cylinder fuel injector fuel injection bad or injector internal plunger parts The thimble was stuck at the maximum fuel supply.

Method of exclusion·

1 Check the quality and quantity of the oil in the oil pan of the diesel engine. The indicators should be in accordance with the diesel oil regulations. If the amount of oil is excessive, some oil should be released to maintain the oil inside the oil pan at the full scale of the oil scale.

2 If the number and quality of the moorings in the oil pan comply with the diesel fuel oil regulations, check whether the fuel supply advance angle has changed. For details of the adjustment method, see Chapter 4 Adjusting the mooring advance angle. After the adjustment is accurate, use a wrench to tighten the two screws on the connector, as shown in Figure 2-75. The sudden failure of the exhaust pipe to emit blue smoke during the operation of the diesel engine is generally caused by a change in the fuel supply advance angle or a blockage phenomenon in the individual fuel injectors. When the old fuel supply is changed at the end of the lead time, the spray atomization quality of the fuel injector should be checked. *3 Remove the squirt of each cylinder, and then fasten the sprayer on the high pressure fuel pipe, and press the start button. The starter is used to drive the rotation of the crankshaft of the diesel engine. The purpose is to atomize the injector without an injector calibration station. If the individual steam 6T spurs have gluten, oyster or no fuel injection, replace the same type of fuel injector. If the sprayer atomization of each cylinder is good, the fault is usually in the piston rod assembly.

Fault 5: diesel generator set diesel engine in normal work, found that the failure analysis of the water in the oil pan:

Oil Cooling Using air-cooled diesel engines during operation, water in the sump is a common fault.

This type of failure is generally caused by damage to the cylinder head, cylinder head, cylinder liner, or body.

Method of exclusion:

In the case of less water in the oil pan, the water radiator should be filled with water and the diesel engine run until the water temperature is 70 °C, and then shut down. The purpose is to allow the body, cylinder liner, or cylinder head cracks to expand so that the fault site can be found. If there is a lot of water in the oil pan, all the waste oil should be discharged, then fill the water radiator with water and pressurize the inside of the radiator through the water inlet. The specific method is as follows:

1 Remove the body panel and irradiate the body with a flashlight to observe if there is any crack on the body. If there is no crack in the body, then the inner and outer walls of the lower part of the cylinder liner should be irradiated to observe whether the water droplet flows into the oil pan from the inner wall or flows from the outer wall. If water drips from the inner wall of the cylinder liner, the fault may be on the cylinder head, cylinder head or cylinder liner. At this time, the cooling water should be drained, the cylinder head and the cylinder head gasket removed, and then the cylinder head gasket and cylinder liner should be checked for damage. If no fault location is found, the carbon deposition at the cylinder head inlet and outlet valves should be cleaned, and then the hydrostatic test should be conducted.

2 The hydrostatic test method is: Several people are used to refer to the channel holes of the cylinder head cover, leaving a water inlet, and then adding water to the cylinder head water channel or applying a layer of soapy water to the bottom of the cylinder head, and then using a high pressure gas cylinder to pass the The nozzle pressurizes the inside of the cylinder head, as shown in Figure 2-11. If water bubbles appear, it indicates that the cylinder head has cracks or blisters, and the same type of cylinder head should be replaced.

2 If there is water dripping from the outer wall of the cylinder liner, it means that the sealing ring on the outer wall of the cylinder sleeve damages the puller and removes the cylinder liner, and then replaces the sealing ring.

Fault 6: Instable diesel engine diesel engine speed

Failure analysis:

After a diesel engine is started, the high and low speed faults are generally caused by failure of air or governor in the fuel supply system. The specific causes are: air and moisture in the fuel supply system; and blockage in the low pressure oil filter. : The oil supply varies from cylinder to cylinder. The trimmer is not working properly.

Method of exclusion.

1 After the diesel engine starts, if the rotation speed is not stable, first observe whether the oil return lines of the high and low pressure fuel lines of the fuel supply system have oil leakage. If there is an oil leak, tighten the oil return screw or replace the fuel line. If no oil leakage is found, check the next step.

2 Loosen the feed screw of the oil pump, remove the oil filter, and remove impurities from the filter, as shown in Figure 5-15.

3 Loosen the bleed screw of the high pressure pump and press the hand pump to remove the air in the mooring, as shown in Figure 5-16.

4 After starting the diesel engine, increase the speed to about 1000r/min and observe if the speed is stable.

If the rotation speed is still unstable, check the governor and injection pump after stopping.

5 Check the flexibility of the moving parts of the oil control and adjustment mechanism. First place the joystick on the high speed position of the governor, and then pull the stop handle (see Figure 5-17). At this time, the oil adjustment gear rod moves in the direction of oil reduction. After releasing the hand, the rack bar should automatically return to the maximum fuel supply position. If the oil pump adjusting rod of the fuel injection pump cannot be automatically returned, it means that the rack rod is not flexible. Check the oil condition in the governor.

6 Check the number and quality of moorings in the governor, as shown in Figure 5-18. Too little oil in the governor can affect the governor's sensitive parts. If there is no oil in the governor, the governor will be serious. 7 If the fault is still not cleared after the above check, remove the high pressure oil pump assembly and send it to the professional pump to supply the oil to each cylinder. Adjust or replace damaged parts.