Excellent Insulation and Cooling of Power Transformer Oil 25#&45# Brand Transformer Oil Specification

Transcription

1 Excellent Insulation and Cooling of Power Transformer Oil 25#&45# Brand Transformer Oil Specification 1

2 1. Description The chemical composition of transformer oil is made up of moderate low viscosity and low pour point naphthenic base oil in high quality antioxidants. the electrical system of the basic protection materials, in the oil-immersed power transformer, reactor, mutual inductor, switch and other oil filled electrical equipment, as the insulation and cooling effect, heat fast, good oxidation stability, high electrical performance. Excellent electrical insulation: Breakdown voltage of the transformer oil measured at least once a year. Main function is to provide electric insulation performance, has very low electrical conductivity and high voltage resistance ability. Reduce the power loss of the equipment. Effectively prevent the high voltage field discharge phenomenon. Control the specific gravity of transformer oil, 20 density is not more than 895 kg/m³ High Cooling Effect: what is the oil used in power transformer? viscosity is appropriate, the cooling effect. By means of cold and heat convection, circulating reflux can transmit timely heat, avoid the power transformer 2

3 overtemperature. Provide effective cooling heat conduction speed, and transitivity. Pour point can be lower than to -40, low temperature performance is good, without any admixture. Strong Antioxidant: high dielectric strength, low dielectric loss factor, good thermal stability and oxidation stability, can prevent the production of acid and oxides. The corrosive sulfur in the transformer oil tends to zero. Because the power transformers is mainly composed of copper wire, iron core insulation and cellulose, etc. The determination of interfacial recogniton transformer oil, the trend of make reliable judgment. Has good oxidation corrosion resistance, and greatly prolong the service life of electrical equipment. 25# & 45# is different types of transformer oil,minimum temperatures below -10, higher than -25 region with 25 #. The minimum temperature below -25, higher than -45 area with 45#. Standard (IEC 296ⅡA & GB ) 2. Performance Requirements 2.1 Appearance At the bottom of the limpid transparent, without suspended matter and sediment, color is usually yellow. 3

4 2.2 Density Related to the composition of oil density. For transformer oil, control its density in some meaning also control the existence of water in the oil amount, especially to prevent power transformer work in cold area, during the winter months could temporarily, don't appear ice phenomenon has more practical significance. If too much water in the transformer oil, when air temperature is low and ice crystals on the electrode, when temperatures rise, attached to the electrode of ice crystal melting increased electrical conductivity, thus appeared the risk of discharge. So the transformer oil density control, general requirements in 20 density is not greater than 895 kg/m after, keep large gap with the density of water. 2.3 Kinematic Viscosity Besides acting as insulation transformer oil, to play the role of a heat dissipation. Therefore, requirements of oil viscosity, appropriate viscosity is too small job security is reduced, affect heat transfer viscosity is too large. Especially in cold area, low temperature oil viscosity too high, 4

5 can not affect the circulation convection and heat transfer ability, can make the normal operation of equipment, or stops running after, to start safely smoothly when enabled. 2.4 Pour Point Pour point (or condensation point) to a certain extent, reflects the low temperature of power transformer oil. According to the climatic conditions, transformer oil by solidifying point and 10, 25, 45 three grades, with pour point in practical measurement. Usually low condensation point of the oil can replace high condensation point, not the opposite. General provisions, transformer oil condensation point should be lower than the lowest temperatures using Flash Point Flash point is to ensure safety in the process of transformer oil in storage and use an indicator, at the same time, the flash point of running oil project supervision is necessary. Low flash point said oil volatile combustible gases, the combustible gas is often the result of electrical equipment of local overheating caused by arc discharge transformer oil warm solution at high temperature. 5

6 Through the determination of flash point can be found that equipment failure in time. At the same time, the new filling the equipment and repair process after the transformer oil, determination of flash point can prevent or discover whether entering the light distillate oil, so as to guarantee safe operation of the equipment. 2.6 Acid Value & Water Soluble Alkali Oil contained in the acid will increase the electrical conductivity of the oil, reduce oil insulation performance. When running at high temperature (80 above) still can make solid fiber insulation aging and cause corrosion, shorten the service life of the equipment. Oil acid value reflects the aging situation of oil, transformer oil in the primary stage of oxidation is easily in low molecular organic acids, such as formic acid, acetic acid, etc. Because these acid soluble good, when the increase of water-soluble acid content (PH value of lower), oil containing water, will accelerate the aging of oil products and corrosion of metal. To strengthen the supervision of the acid value, to take timely correct maintenance measures are very important. 6

7 2.7 Oxidation Stability Oxidation stability is an important indicator of transformer oil. Power transformer is continuous long-term operation equipment, and cannot be easily outage maintenance. Transformer oil change not only influence the power supply of time, but also consume large amounts of transformer oil, so the requirement of transformer oil and durable longer (general requirements and durable more than 15 years). Electric field under the action of metamorphism is slow for a long time, which requires good oxidation stability. Transformer oil is generally work under 60-80, the long-term contact with air, such as iron and copper metal, lead to oil oxidation, produce water, Low molecular acid and high molecular polymer. Not only destroys the electrical properties of oil, and cause corrosion, shorten the service life of equipment. Antioxidant capacity of transformer oil and its refined depth, generally after moderate fine add antioxidant oil oxidation stability is good. Oxidation stability to guarantee project, measured at least once a year. 7

8 2.8 Breakdown Voltage Breakdown voltage test transformer oil is tolerance limit an indicator of electrical stress is very important. Judging transformer oil water cut and other suspended matter pollution degree. Before the injection equipment, oil dry and filter degree of inspection. Run, oil breakdown voltage is reduced, is one of the power transformer work dangerous signal. In order to ensure the project breakdown voltage, measuring at least once a year. User before use, must be filtered and determination again 2.9 Dielectric Loss Factor Dielectric loss factor, also called of dielectric loss Angle, said under the effect of electric field, Electrolyte polarization and electrolyte conductance, caused by the loss of electric power. Pure hydrocarbon for non polar compounds, under the effect of electric field does not occur or rarely inversion. 8

9 But impurity components, such as gelatin and acids for polarity, under the effect of electric field, the change with power line direction and inversion. This inversion consumed part of the electric energy transformed into heat. Not only loss of electric energy, and increase the temperature of the power transformer, reducing the working ability of the power transformer, power transformer accelerated aging and deterioration. Dielectric loss factor to determine the size of the degree of oil degradation or contamination is very sensitive. Usually new polarity impurity content in the oil, the dielectric loss factor are also small. But when oil degradation or mixed with other impurities, with polar impurities in the oil or the increase of the content of colloid material dielectric loss factor will also increase Interfacial Tension Determination of interfacial tension between oil and water, is to check the oil due to aging, is contained in a simple and effective method of soluble polar impurities. Interfacial tension of oil in the early stage of ageing, change is 9

10 quite quickly. Aging medium, and its change rate also gradually reduced, while generated sludge significantly increased. This method can also be used to generate the trend of oil sludge make reliable judgment Moisture Moisture is one of the important reasons of power transformer insulation aging. Increase of water content in insulating material of transformer oil, directly led to the decrease of the insulation performance, and would lead to oil aging, affect the reliability of the equipment operation and service life. To strict supervision, water is essential to ensure the safe operation of the equipment of a pilot project. Generally at 20, the ability of transformer oil dissolved water for about 40 mu L/L, through industrial dewatering device can make the water content of transformer oil dropped below 1040 mu L/L. Generally, the higher the voltage of power equipment for oil water content is lower. 10

11 The water also can promote the organic acid corrosion of copper, iron and other metals, produced by saponification, worsen oil dielectric loss factor, increase the absorption of moisture, oil, and plays a role of catalytic oxidation of oil. Are thought to be affected with damp be affected with damp oil than dry oil aging speed to increase 2-4 times, so for a long time people in transformer oil, the presence of water to give great attention. Users before use must be repeated filtration dehydration to electrical properties after all qualified, can join the electrical equipment Analysis Capability & Aniline Point & Than Dispersion Analysis of transformer oil gas, it is to point to oil under high electric field intensity, due to the instantaneous discharge or fringe discharge, result in dehydrogenation of oil products. Emergence of hydrogen and can be absorbed by the product itself, not in oil form bubbles, the device electrical performance or burst damage oil, this is inspiratory of transformer oil (gas). For the large capacity of the fully sealed type transformer is 11

12 especially important. The performance of transformer oil absorption or exhalation hydrogen and its composition. Under high electric field intensity, aromatic and unsaturated hydrocarbon tends to absorb hydrogen and alkanes tend to hydrogen evolution, naphthenic is basic don't suck. To balance the tendency, absorption should contain a certain amount of aromatic hydrocarbons in transformer oil, especially the single ring, double ring aromatics. In ehv transformer oil standard specifies the requirements analysis, and no such request in the ordinary transformer oil. Aniline point and dispersion is associated with the hydrocarbon composition of oil, can indirectly reflect the ability analysis of oil gas and dissolved. Ideal components of transformer oil is naphthene, single or double ring aromatics and isomerization alkane. Alone in terms of analysis, are best, aromatic hydrocarbons, olefins, cycloparafin hydrocarbon. 12

13 3. Specifications & selection principle 3.1 Standard Specifications International general there are four main transformer oil specification. International electrotechnical commission (IEC) used in transformer, circuit breaker, unused mineral insulating oil specification: IEC American society for testing and materials (ASTM) used in the electric installation of mineral insulating oil specifications: ASTM D3487. The British standard: BS148. German standard: DIN 57370/0370. Other countries and transformer manufacturers, also made the respective electrical insulating oil specification. Ordinary transformer oil reference: IEC (Ⅱ A) According to the characteristics and oil naphthenic base, paraffin base crude oil resources, according to the pour point and 10, 25, 45 three grades; Ultra-high voltage transformer oil (500 KV and above), with 13

14 reference to: ASTMD3487 (Type Ⅱ) & petrochemical industry standard: SH According to the pour point and some points of 25# and 45# two grades, and coagulation are mainly composed of naphthenic base crude oil production. 3.2 Selection Principle Generally by the use of electrical equipment area, climate condition, the voltage level to choose transformer oil. In order to ensure the winter outdoor transformer can be put into operation at any time, with the provisions of solidifying point is not higher than the local minimum temperature of transformer oil. Lowest temperature below 10, higher than 25, with 25 # transformer oil, Minimum temperature below 25 higher than 45 - region, with 45 # transformer oil. Low condensation point of the oil can replace high solidifying point, not the opposite. Standard "In the operation of the transformer oil quality standards" also stipulates, add a drop of outdoor switch oil 14

15 solidifying point: the temperature is not lower than -5, oil solidifying point is not higher than The temperature is not lower than -20, oil solidifying point is not higher than- 25. The temperature below -20, oil solidifying point is not higher than -45. In the 330 KV voltage level, choose EHV transformer oil. 330 KV and below the oil filled electrical equipment, using the ordinary transformer oil. 4. Quality Performance & Use Transformer oil belongs to inhibit formulations transformer oil. Transformer oil production with naphthene base transformer oil is given priority to, complementary with intermediate base oil. Main processing process of distillation, solvent dewaxing, furfural refining, hydrofining, clay refining, etc. Different combination. Main varieties are 25# & 45# normal transformer oil. 4.1 Summary Naphthenic base type 25#, 45# transformer oil is made from moderate low viscosity and low pour point naphthenic base oil 15

16 to join quality antioxidants modulation of transformer oil. Has good heat transfer quickly, oxidation stability, electrical performance, etc. Reliable product performance, production under strict quality control procedures, product resources are fixed. 4.2 Quality Grade Naphthenic base type 25#, 45 # transformer oil conform to IEC 296 (1982) ⅡA specifications and standards. 4.3 Scope Of Application Naphthenic base type25#, 45 # transformer oil, the medium of electrical insulation used for transformer, circuit breakers and other electrical equipment. 4.4 Characteristics Excellent electrical insulation properties, which can effectively prevent the high voltage field discharge. High dielectric strength, low dielectric loss factor, good thermal stability and oxidation stability, can prevent the production of acid and oxides, prolong the service life of equipment. Provide effective cooling heat conduction speed, and transitivity. 16

17 Low temperature performance is good, without any admixture, pour point can be lower than to 40. Environment friendly, does not contain any PCBS. 4.5 Storage and Protection Transformer oil is very vulnerable to moisture, all kinds of solid particles, fibers, such as sulfide pollution. Transformer oil, it is very important to keep dry and clean. Storage containers must be dedicated, and try to place indoors or the climate controlled environment. 4.6 Packaging Iron drum packaging. Specification: 200 L & 185 kg/barrels(oil weight: 170 kilograms, Barrel weight: 15 kg) High barrels: 1000 mm, Diameter: 650 mm. 17

18 5. Data Parameter Item Quality Standard Typical Data Test Method Brand 25# 45# 25# 45# Appearance Transparent, Without Suspended Matter and Mechanical Impurities Density (20) ( kg/m³) Visual GB/T1884 GB/T1885 Kinematic Viscosity(m m2 /s) / GB/T / 1800 / 1500 Pour Point ( ) -22 < GB/T3535 Condensation Point ( ) -45 <-45 GB/T501 Flash Point(Open) ( ) GB/T261 Acid Value (mg KOH/g) GB/T264 Corrosive Sulfur Non-Corrosive SH/T0304 Oxidation Stability Acid value After Oxidation (mg KOH/g) After Oxidation Precipitation (%) SH/T0206 Water-soluble acid or alkali No No No GB/T259 Breakdown Voltage (2.5 mm) Delivery Of Interval ( KV) Dielectric Loss Factor (90 ) GB/T GB/T5654

19 Interfacial Tension (Mn/m) GB/T6541 Moisture ( mg/kg) Report SH/T Credentials 6.1 (IQNet) Management Excellence Award 6.2 Occupational Health and Safety Certification 19

20 6.3 Environmental Management Certification 20

21 6.4 (BUREAU VERITAS) ISO9000 Certification 21