Vacuum Transformer Oil Purification System is used to remove water, gas and impurities for improving the electrical resistance of oil and the paper insulation, but also to a certain extent, improve the physical and chemical properties of oil.
Power distribution transformers are mostly installed in the open air environment, insulating oil (transformer oil) by external impurities, and air contact and the equipment itself running a higher temperature, the quality of the oil gradually deteriorated. After the deformation of the insulating oil (transformer oil) will not play the proper insulation, cooling effect. In order to prevent the safe operation caused by deterioration of oil quality is affected, the normal operation of the regular distribution of oil samples for analysis, and according to the analysis of the oil for the corresponding treatment. The inspection cycle for chemical monitoring of the distribution of oil is specified for at least 3 years. Conventional inspection items include acid value, water-soluble acid, flash point, breakdown voltage, appearance.
It should be noted that if the Transformer Oil Purification System is often loaded with a relatively high load, the number of tests should be increased on the basis of the specified test cycle. If the tested items are significantly close to the limits of the control, the number of tests should be increased. The quality of the running oil varies greatly depending on the degree of aging and the presence of impurities, and is usually not a test item alone as a basis for evaluating the state of the oil. Which should be based on the determination of several major characteristics of a comprehensive analysis of indicators.
1. Acid value
The ultra-limit is greater than 0.1 mgKOH / g. There are four possible reasons for exceeding the limit: overload operation; consumption of antioxidants; fill the wrong oil; oil contamination. The following values are taken for the acid value exceeding the limit: the cause of the investigation, the number of tests, the amount of the antioxidant to be measured and the appropriate addition, and the regeneration of the transformer oil. If the economy is reasonable,
2. Water-soluble acid value
Its super limit is less than 4.2. There are two possible reasons for exceeding the limit: oil aging; oil contamination. The following measures can be taken to increase the number of tests and compare the acid value with the acid value. The oil regeneration treatment, if the economy is reasonable to do oil change treatment.
3. Breakdown voltage
Its super limit is less than 20KV. There are two possible reasons for exceeding the limit: the water content in the oil is too large; the oil is contaminated with impurity particles. The following measures can be taken for the breakdown voltage beyond the limit: to identify the cause, vacuum filtration treatment, plate and frame pressure oil filter processing or replacement of new oil.
4. Flash point
The super limit is less than 130 ° C. Or 5 ° C lower than the previous test value. There are two possible reasons for exceeding the limit: the device has a local overheating fault; If the flash point exceeds the limit value, the following measures can be taken: to identify the cause, to eliminate the fault; to vacuum degassing machine, or oil change treatment.
If the appearance of visual oil is opaque, there are visible impurities or suspended solids. Or oil is too deep, the oil appearance is abnormal. Appearance may be due to abnormal: oil contains water, fiber, carbon black and other solids. The following measures should be taken for oil with unusual appearance:
If the oil is blurred, turbid white, indicating that the oil contains water, should check the water content. If it is found that the oil contains carbon particles, black color, and even coke smell, there may be an internal arc or partial discharge failure, should be combined with other tests, investigate the cause, troubleshooting. If the oil color is dark, and the color of the oil has changed significantly, it should be noted that the aging of the oil is accelerated, can be combined with oil acid value test analysis, or strengthen the transformer oil operating temperature monitoring.