Diesel engine unsealing
In order to prevent the diesel engine from rusting, when the product leaves the factory, both inside and outside is sealed with oil. Therefore, after the new unit is installed and meets the installation requirements, it must be unsealed before it can start. Otherwise, it will cause the danger. So it should be taken seriously.
If you don’t know how to do commissioning after a diesel generator set is installed, this article will guide you to learn more. Before the generating set is put into operation, a comprehensive inspection must be carried out.
The steps to remove the oil seal are as follows:
1) Heating the diesel above 45 ℃ to 56 ℃for cleaning and removing the external anti-rust oil.
2) Heating water aover 90 ℃, then continuously pouring water through the water jacket outlet, flowing out from the plug assy Irain (or water pump inlet) on the side of the cylinder body, continuously for 2--3 hours, and rolling the crankshaft discontinuously to make the anti-proof oil of piston top, cylinder liner surface and elsewhere dissolves and flows out.
3) Clean the oil sump with clean diesel oil and replace it with new oil.
Cooling and fuel system, fuel injection speed regulation system, water pump and starting drive system should be cleaned and checked in accordance with the requirements of the instructions, and sufficient clean cooling water should be added, starting batteries should be fully charged, and preparations should be made for the start up of the machine.
Inspection before the genset has a test
1. Inspection procedures
1) Check whether the surface of the unit is clean. The anchor nut, flywheel screw and other moving parts are not loosened. It must be fastened if any problems found.
2) Check whether the clearance of each part is correct, especially check the intake & exhaust valve clearance to make sure it meets the requirements.
3) Put each cylinder in the pressure reducing position, rotate the crankshaft to check if there is any abnormal sound in the operating sound of the cylinder parts, and whether the crankshaft rotates freely. At the same time, pump the engine oil into the friction surface. Then, close the pressure - reducing device, shake the crankshaft, and check the cylinder for air leakage. If the crankshaft is very difficult to shake, it indicates that the compression is normal.
4) Check fuel supply system, steps are as follows:
① Check whether the venthole on the fuel tank cover is smooth and clean if there is dirt in the hole. Whether the diesel added meets the required brand number, whetehr oil mass is adequate, and turn on the oil circuit switch.
② Open the mechanism of decompressor to shake the crankshaft. If each cylinder has a clear injection sound, it indicates that the injection is good. Whereas, there may be air in the oil line. This moment, you should rotate the fuel filter and injection pump air bleed screw to eliminate the air in the oil line.
③Check whether there is oil leakage in the oil pipe and joint, and deal with the problems in time if found.
5) Check water cooling system, procedures are as follows:
①Check whether the cooling water in the tank is sufficient. If the water is insufficient, clean soft water should be added.
②Check whether there is water leakage in the joint pipe and solve the problem in time.
③Check that the impeller rotation of the cooling water pump is flexible and the belt is tight and appropriate. When checking whether the belt is tight, push the middle of the driving belt. It is suitable if the driving belt is pressed down 10-15mm.
6) Check lubricating system
①Check the oil pipe and pipe joints for oil leakage and solve the problem in time
②Check the oil mass of the oil pan, draw out the oil dipstick next to the crankcase, observe whether the height of the oil surface is in accordance with the rules, otherwise, add oil to the diesel engine, add No.8 or 11 engine oil in winter, and add No.14 oil in summer. Check again, if found that the oil surface height is above the normal, should be carefully analyzed the reasons for the increase in oil, usually there are three reasons.
a. Add too much oil
b. Diesel oil leaks into the crankcase and dilutes the oil.
c. The cooling water leaked into the oil.
7) Check starting system
a. First, check whether the specific gravity of starting system is within the range of 1.240 ~ 1.280. If the specific gravity is less than 1.180, it indicates that the battery power is insufficient.
b. Check whether the power line is correct.
c. Check whether there is contamination or oxidation on the battery terminal, it should be cleaned up.
d. Check whether the electric contact of starting motor and electro-magnetic control is good.
Installation and inspection procedures of ac generator are as follows:
1) The coupling between alternator and diesel generator requires that the parallelism and concentricity of the coupling are less than 0.05 mm. In actual use, the requirements may be slightly lower, about within the 0.1mm, over the assembly affects the normal operation of bearing, resulting in damage, good coupling should be fixed with positioning pin. The coupling should be re-tested before installation.
2) When a sliding bearing generator is coupled, the height of the generator center should be adjusted slightly lower than the center of the diesel engine, so that the weight of the flywheel on the diesel engine will not be transferred to the generator bearing. Otherwise, the generator bearing will bear extra weight of the flywheel, which is not conducive to the formation of oil film of the sliding bearing, resulting in heat and even burning of the bearing. The couplings of such generator are not allowed to carry any weight.
3) When installing the generator, make sure that the cooling air is free from the entrance, and avoid the release of hot air into the generator. If there is shutter on the ventilation cover, the window should be down to meet the protection level requirements.
4) The mechanical coupling of single bearing generator should pay special attention to the uniform air gap between stator and rotor.
5) According to the schematic diagram or wiring diagram, select the appropriate power cable, use copper joint to connect, copper joint and busbar, busbar and busbar after fastening, the local gap is less than 0.05 mm, the distance between the conductors is less than 10 mm, and the necessary ground wire should be installed.
6) The terminal head of the generator outlet box is marked with U, V, W, N, which does not mean that the actual phase sequence but depends on the direction of rotation. UVW is printed on the certificate to indicate the actual phase sequence in clockwise rotation, VUW represents the actual phase sequence in counterclockwise rotation.
7) If the neutral point of each generator in the power supply system is connected with each other, or when the neutral point of the generator is connected with the transformer and its load neutral point, the neutral line current of 3 times the frequency of the neutral line will be produced during the operation of the unit. Therefore, it is necessary to measure the midline current of the generator under various load conditions that may occur in operation. In order to keep the generator from overheating, the midline current shall not exceed 50% of the rated current of the alternator. If the midline power is too large, the central line reactor should be installed.
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