Is the transformer leaking oil? Don't panic, let's talk about what kind of oil it is first

Oil immersed transformers are inevitably prone to insulation oil leakage problems. Traditional transformer insulation oil is mineral oil, which is toxic and difficult to degrade. Once leaked, it can cause significant environmental and economic losses. So if it is a plant insulated oil transformer, what are the hazards of leakage and how should it be handled? Today we will talk about the causes, hazards, and treatment methods of transformer insulation oil leakage.

Reasons for insulation oil leakage

(1) Quality issues with the materials themselves (such as air holes in the internal welds of transformers, cracks and sand holes in the oil storage tank, etc.)

(2) Material damage (corrosion damage to pipelines, decreased strength of materials due to fatigue, aging, stress concentration, etc.)

(3) External force damage (damage to structures using oil equipment such as barbaric construction, natural disasters, vehicle collisions, etc.)

(4) Internal pressure damage (such as fuel tank cracking due to severe cold and imbalanced internal and external pressure; long-term operation of the fuel tank generates a large amount of heat inside, causing the tank to expand, deform, and rupture.)

(5) Sealing failure (unreasonable sealing design, poor manufacturing quality, incorrect installation, aging, corrosion, wear of sealing components, etc.)

(6) Human factors (poor management, negligence, illegal operations, etc.)

The hazards of insulation oil leakage

1. The hazards of mineral oil leakage

The biodegradation rate of mineral insulating oil generally does not exceed 30%, while the biodegradation rate of organic silicone oil is less than about 10%. The list of carcinogens published by the International Agency for Research on Cancer (IARC) of the World Health Organization includes untreated or lightly treated mineral oil in Group 1 of the list of carcinogens, and mineral oil, highly refined, in Group 3 of the list of carcinogens.

When mineral oil pollution exceeds a certain limit, it will be absorbed by certain components in food raw materials and enriched in plant bodies. Plants may also be contaminated by mineral oils such as asphalt and lubricating oil that drip onto the ground during the drying process. Mineral oil contains many harmful substances to living organisms, such as heavy metals, aromatic hydrocarbons, and long-chain alkanes, which can cause harm to living organisms. It is difficult for various organisms to decompose mineral oil, resulting in the accumulation of toxic mineral oil in the organism, which ultimately reaches the human body through the food chain. Once long-term intake of foods with excessive mineral oil content or containing mineral oil can cause significant obstacles to the human digestive system, such as vomiting, diarrhea, and coma caused by long-term consumption of large amounts of food contaminated with mineral oil. More seriously, ingestion of industrial mineral oil by the human body can result in acute and chronic poisoning, damaging various cells in the body and ultimately causing damage to the nervous system. In addition, it can also damage the human respiratory system, reducing the number of red blood cells in the blood and leading to respiratory failure.

2. The hazards of plant insulation oil leakage

The main raw materials selected for plant insulating oil are natural oil crops such as soybeans, rapeseed, sunflower seeds, cottonseeds, and camellia seeds, which are originally used for consumption and are therefore environmentally friendly, non-toxic, and almost harmless to living organisms. At the same time, it contains abundant unsaturated fatty acids such as oleic acid, linoleic acid, and linolenic acid. These unsaturated fatty acids are prone to losing hydrogen atoms and producing free radicals, with poor oxidation stability. They can degrade on their own in natural environments, and their molecular chains gradually break to form low chain organic compounds that are easily decomposed. The research results indicate that plant insulating oil can be almost completely biodegraded, with a short-term degradation rate of over 97%. It can be seen that plant insulating oil has a high biodegradation rate, minimal impact on the environment, and is a renewable resource that meets the requirements of current social development. However, compared to mineral oil, vegetable oil has a higher acid value and viscosity. Therefore, theoretically, leaked vegetable oil may cause corrosion to mechanical components. However, in practice, the acid value of vegetable insulating oil is extremely low and the acidity is not strong. The situation of equipment corrosion caused by leakage can be almost ignored.

Response measures for insulation oil leakage

1. Response measures for mineral insulation oil leakage

When mineral insulating oil leaks from soil, personnel in the contaminated area should be quickly evacuated to a safe zone and isolated, with strict restrictions on entry and exit. Cut off the fire source. It is recommended that emergency responders wear self-contained positive pressure respirators and firefighting protective clothing. Cut off the leakage source as much as possible. Prevent entry into restricted spaces such as sewers and drainage ditches. Minor leakage: Absorb with sand, vermiculite, or other inert materials. Or burn it on site while ensuring safety. Massive leakage: constructing embankments or digging pits for containment; Cover with foam to reduce steam disaster. Transfer to a tanker or dedicated collector using an explosion-proof pump, and recycle or transport to a waste disposal site for disposal.

If it is on the water surface, the first step in cleaning up mineral insulation oil leaks is to cut off the pollution source and prevent the floating oil area from continuing to expand. The second step is to remove oil pollution from the sea surface through some physical methods, such as using a suction machine to absorb oil, using a water grid and skimmer to scrape oil, using an oil absorbing felt to adsorb crude oil and recycle it. The third step is to spray chemical oil dispersants, which promote the decomposition or sedimentation of mineral oil through chemical reactions, forming tiny spherical objects that can dissipate in water. But the disadvantage of using chemical reagents is that they may cause secondary pollution and can only be used to clean a small amount of oil stains.

It should be noted that when dealing with mineral insulation oil leaks, protective measures should be taken, such as wearing respiratory protection, chemical safety goggles, anti-static work clothes, and benzene resistant gloves. Open flames are strictly prohibited at the work site, and long-term repeated contact should be avoided.

2. Response measures for plant insulation oil leakage

When insulation oil droplets are found in electrical equipment, due to the probability of igniting the oil, the power should be immediately turned off and the oil supply source should be cut off. However, due to the non-toxic and harmless nature of vegetable oil to the environment, its high flash point, good fire resistance, and ability to degrade on its own, there is no need to overly worry about poisoning and combustion risks.

When there is a slight leakage of plant insulation oil, it can be cleaned with an oil absorbing cloth and cleaning agent.

When plant insulating oil leaks into water, although it is non-toxic, long-term coverage of the oil on the liquid surface may lead to deterioration of water quality. It is necessary to use isolation tape to surround the leaking surface and use a water pump to remove the oil layer from the liquid surface. Cleaning agents can also be used to remove plant insulating oil from water.

When plant insulating oil leaks into the soil, it can quickly biodegrade on its own. Because soil serves as an absorbent, it provides favorable conditions for natural biodegradation. Meanwhile, biodegradable catalysts can also be used to accelerate the degradation rate.