What are the reasons for the overheating of the diesel fog cannon generator?

DATE:2021-03-23 13:40:03



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The temperature of diesel fog cannon generators has strict standards. If the temperature is too high or too low, it will damage the unit. In severe cases, it will cause accidents. There are many reasons for the overheating of the generator:

(1) The diesel fog cannon generator does not operate in accordance with the specified technical conditions. For example, if the stator voltage is too high, the iron loss will increase; the load current is too large, and the copper loss of the stator winding will increase; the frequency is too low, which will slow down the cooling fan speed. , It affects the heat dissipation of the generator; the power factor is too low, so that the rotor excitation current increases, causing the rotor to heat up. Check whether the indication of the monitoring instrument is normal. If it is abnormal, make necessary adjustments and treatments to make the generator run in accordance with the specified technical conditions.

(2) The three-phase load current of the generator is unbalanced, and the overloaded one-phase winding will overheat; if the difference between the three-phase current exceeds 10% of the rated current, it is a serious phase current imbalance, and the three-phase current imbalance will produce Negative sequence magnetic field, thereby increasing loss, causing heating of magnetic pole windings and ferrules. The three-phase load should be adjusted so that the current of each phase is as balanced as possible.

(3) The air duct is blocked by dust and poor ventilation, which makes it difficult for the diesel generator to dissipate heat. The dust and grease in the air duct should be removed to make the air duct unobstructed.

(4) The inlet air temperature is too high or the inlet water temperature is too high, and the cooler is blocked. The temperature of the inlet air or water should be lowered to clear the blockage in the cooler. Before the fault is eliminated, the generator load should be limited to reduce the generator temperature.

(5) Bearing too much or too little grease should be added according to the regulations, usually 1/2 to 1/3 of the bearing chamber (the upper limit is taken for the low speed, and the lower limit for the high speed), and should not exceed 70% of the bearing chamber is appropriate.

(6) Bearing wear. If the wear is not serious, the bearing will locally overheat; if the wear is serious, it may cause friction between the stator and the rotor, causing the stator and rotor avoidance to overheat. The bearings should be checked for noise. If friction between the stator and the rotor is found, the machine should be shut down immediately for maintenance or bearing replacement.

It should be noted that sometimes the temperature is too high, and the heat dissipation temperature of the diesel fog cannon generator will also increase. At this time, although there is no heating failure, it is necessary to take timely cooling measures!