TRANSFORMER OIL RECOVERY PLANTS OF URTM SERIES
Purpose
These plants are intended for recovery (removal of ageing products) of mineral-based transformer oils and restoring the following parameters:
- acidity number (KOH/g);
- dielectric loss angle tangent tg δ;
- color.
Restoring these parameters enables one extending service life of oils because, due to regulatory requirements, oil should be either exchanged or reconditioned if during transformers’ operation these parameters have exceeded the normative ones.
Plants also ensure preparation of stability additive (ionol solution) for introduction to transformer oil.
If plant is provided with thermo-vacuum treatment unit, used oils undergo drying and outgassing process.
Application
Plants are used in repair of power transformers and reactors with voltage up to 1150 kV inclusively, and for recondition of transformer oils and also at mineral oil facilities in view of further regeneration.
Components
Transformer oil recovery plants consist of oil reconditioning unit, oil filtration unit, stability additive introduction unit (ionol) and sorbent reactivation unit. The plant includes oil pumps, compressed air-blowers, check valves, fluid meters and other components that ensure the relevant control and operation of the plant in different modes. The performance of the plant is governed from its control cabinet.
The oil reconditioning unit is designed to improve oil parameters up to indices shown in the Para. 2 of the Table.
The oil filtration unit is designed for heating and cleaning the oil from mechanical impurities to the following parameters:
- contents of mechanical impurities is not more than 10 g/t due to GOST 6370, cleanliness class is at least 9 due to GOST 17216.
The stability additive introduction unit (ionol) ensures preparation and introduction of stability additive to transformer oil.
The sorbent reactivation unit ensures rehabilitation of sorbents after their saturation with ageing products of transformer oil.
Design features
Plants are designed as a metal container- module provided with operator’s work- area and furnished with all relevant equipment; the module is a weather-proof structure heated in cold seasons.
Sorbent is reconditioned in adsorbers, and ageing products are extracted from transformer oil, with no need to evacuate the sorbent, thus keeping the environment free from pollution with oily stuff.
Oil heater of indirect heating type partitioned in two (20+20) kW sections, thus allowing to set a required temperature regime, whereby one section performs in base mode, while another section provides oil temperature variation within a task specified range.
Protection and automation system provides automatic deactivation of oil-heater in case if oil flow is suspending or getting overheated, which is followed with alarm signal.
Plants are provided with a three-stage filtration system.
The control panel enables regime-selection and provides control of a performance-mode selected.
Oil regeneration and sorbent reactivation processes can be governed either manually (setting parameters and tracking the process by operator attendance) or automatically (by processor controlled maintenance of parameters preselected by the operator). Sorbents are prepared specifically so as to ensure several hundred reactivation cycles.
By its design the plants are manufactured in the following model series:
- URTM – 1х2-I U1;
- URTM – 2х2–I U1;
- URTM – 3х2–I U1;
- URTM – 2х2-BV–I U1;
- URTM – 3х2-BV–I U1,
where:
- URTM is transformer oil recovery plant;
- 1х2 is two lines with one adsorber each;
- 2х2 is two lines with two adsorbers each;
- 3х2 is two lines with three adsorbers each;
- BV is built-in thermo-vacuum (outgassing) treatment unit;
- I is built-in stabilizer additive introduction unit;
- U1 is climatic category.
Operating conditions and certification
Plants are manufactured in compliance with Specifications of JSC «PDTB «ELEKTROTECHMONTAZH» TU U 34.04624312.018-98.
Plants have certificates of conformity in certification system «UkrSEPRO» of Ukraine and certifies in accordance with «Technical Regulations on Safety of Machines and Equipment» approved by Decree No. 753 dated 15.09.2009 of the Government of the Russian Federation.
Plants are manufactured due to Quality Insurance System in compliance with ISO 9002.
Type of climatic category: U1, per GOST 15150-69.
Location on open site or under shelter.
Average service life is minimum 10 years, and the warranty period is 12 months.
Maintenance staff consists of two operators.
Ecological safety is according to GOST 12.1.005-88.
Fireproof safety is according to GOST 12.1.004-91.
Electrical safety is according to GOST 12.2.007.0-75.
Plants characteristics
Technical plants characteristics are represented in the following Table:
Table 1
| Name of parameter | Value | Notes |
|---|---|---|
| 1. Unit Capacity, not less than: | ||
| a) in oil pumping regime, m3/hr | 4 | |
| b) 1) in oil outgassing and drying regime, m3/hr | 1,2 | |
| c) in oil reconditioning regime, l/cycle | 6000 2) | |
| 2. Post - treatment oil parameters: | ||
| a) acidity number as per GOST 5985, КОН/g, not more than | 0,01 | |
| b) dielectric loss angle tangent (tg δ) as per GOST 6581, % at 90°С, not more than | 0,5 | |
| c) 1) moisture contents as per GOST 7822, % (g/t), not more than | 0,001 (10) | |
| d) content of mechanical impurities as per GOST 6370, g/t, not more than | 10 | |
| e) content of stabilizer additive (ionol), %, not less than | 0,3 | |
| f) cleanliness class as per GOST 17216, at least | 9 | |
| g) 1) breakthrough voltage as per GOST 6581,kV, not less than | 70 | |
| 3. Oil loss during regeneration, %, not more than | 0,5 | |
| 4. Quantity of adsorbents (adsorbents А and В), pcs. | 2÷63) | |
| 5. Amount of sorbent load in adsorber, kg | 300÷350 | |
| 6. Number of sorbent reactivation cycles, pcs., ,more than | 400 | |
| 7. Duration of sorbent reactivation with cooling, hours, not more than | 6+12=18 | |
| 8. Oil temperature, °С: | ||
| a) in oil pumping regime | 20÷85 | |
| b) 1) in oil outgassing and drying regime | 40÷50 | |
| c) in oil reconditioning regime | 65÷75 | |
| 9. Nominal filtration fineness size, mcm | 50/20/5 | three stages |
| 10. Filtration index (β-coefficient), not less than | 400 | |
| 11. Output pressure, MPa, not less than | 0,2 | |
| 12. Nominal power of oil heater, kW | 40 | |
| 13. Three- phase 50 Hz power supply voltage, V | 380 ± 10% | |
| 14. Maximum consumption power, kW | 65 | |
| 15. Installed capacity, kW | 75÷1053) | |
| 16. Overall dimensions, m, not more than: | ||
| a) length | 4,0÷5,83) | |
| b) width | 2,23 | |
| c) height | 2,12 | |
| 17. Weight, kg, not more than | 4400÷69003) |
NOTES:
1) This parameter is provided in case of availability of thermo- vacuum processing unit.
2) Value of oil per cycle depends on characteristics of original oil. The Table represents amount of reconditioned oil before the parameters indicated in Paragraph 2 of the Table with following parameters of original oil: acidity number not more 0,1 KOH/g, dielectric loss angle tangent tgδ at 90°C not more than 5%.
3) Value of this parameter depends on a model.
Brief description of operation
The plant can be operated in several regimes:
- oil repumping;
- oil reconditioning;
- oil outgassing and drying (provided if plant is completed with a thermo-vacuum treatment unit);
- preparation of stability additive solution (ionol solution) for input to transformer oil.
Used oil is delivered to the input of oil filtering unit where it is heated up to temperature of its further service regime either up to 20 ÷ 85°C (at repumping mode) or to 65÷ 75°C (at regeneration mode).
While in regeneration mode, oil (heated up to 65 ÷75°C) is delivered, for example, to the oil recondition unit (adsorber A). At the same time, at the oil recondition unit (adsorber B) sorbents may undergo rehabilitation using the sorbent-reactivation unit. Transformer oil refined from ageing products is delivered from adsorber A to input of oil filtering unit to undergo the filtration up to achievement the parameters indicated in Para. 2, Subpara. c), f) of the Table.
The sorbent material undergoes recovery without need of being evacuated from adsorber, through thermal treatment and subsequent cooling by air blower that is the part of the plant.
Operation
Plants according to their operation mode are manufactured with manual and automatic operation.
In manual operation, operator can set and hold on all routine operation-regime settings and parameters by handling all relevant knobs, arms, levers, valves etc, the set mode parameter control is carried out using instruments.
Pumps, fans and other electro-technical equipment are actuated by switch buttons and controls on the control cabinet.
If a plant is manufactured with automatic operation, operator is free to select any desirable operating mode by aid of a multi-functional controller.
Plant performance in a selected mode is supervised due to a pre-programmed sequence, whereby all parameters required for proper plant functioning are maintained.
Actual information is displayed on a touchscreen panel simultaneously with online visualization on integrated action logic chart.
In case of deviations from specified settings or on completion of plant operation, relevant messages appear on the operator’s panel, along with sonic duplication by alarm signalization.
Automatic operation system provides an ability to transfer the plant into manual operation mode, whereby operator can change settings displayed on the control panel by pressing the actuator in the scheme, thus shifting it to manual operation mode.
