water in oil Archives - Sea Marconi https://seamarconi.com/it/tag/acqua-in-olio/ Sustainable solutions for life cycle management (LCM) of electrical transformers with insulating oils Fri, 19 Apr 2024 08:14:27 +0000 en-US hourly 1 https://wordpress.org/?v=7.0.1 Spain 2020/21 Drying of transformer oil and paper https://seamarconi.com/en/portfolio_item/spain-202021-drying-of-transformer-oil-and-paper/ Tue, 20 Apr 2021 10:18:42 +0000 https://seamarconi.com/it/?post_type=portfolio&p=114415 The post <strong>Spain 2020/21</strong> Drying of transformer oil and paper appeared first on Sea Marconi.

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Scenario

3 single-phase transformers installed in a thermoelectric power plant in southern Spain

Technical characteristics of the transformer:

Manufacturer .: xxx
Year: 1977
Power [MVA]: 216
Voltage [KV]: 220/22
Mass of oil [Kg]: 15,650 each.

Problem

Periodic analyzes of the oil showed a condition of hydration of the cellulosic insulation. The estimated water content in solid insulation is between 3 and 4% by weight, a typical condition for equipment with more than 30 years of service.

Solution

Sea Marconi performed the following activity:

Dehydration or drying of transformer (paper/oil)

The process was carried out with the transformer on-load under charge.

Detail of the phases of the intervention

  • Hydraulic connection of treatment equipment with temporary out of service transformer
  • Execution of the dehydration process with the transformer on-load
  • Disconnection of equipment with transformer on-load

 

Criteria for stopping treatment

  • Water in oil <10 mg / kg at t> 40 ° C
  • Breakdown voltage> 70 kV
  • Extracted water <250 ml / 24h

Treatment details

The process was carried out with the transformer on-load.
The temperature of the oil in the tank (top oil) was kept constantly above 70 ° C through the use of an auxiliary heating equipment.
Simultaneously the oil was recirculated through a vacuum dehydration equipment. Overall, about 15 liters of water were extracted from each device.

Duration of the intervention: 6 weeks (2 for each transformer)

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]]> Drying papers and transformer France 2008 https://seamarconi.com/en/portfolio_item/drying-papers-and-transformer-france-2008/ Fri, 31 May 2013 14:52:22 +0000 http://www.bioenpro.com/wordpress01/?post_type=portfolio&p=4209 The post Drying papers and transformer <strong>France 2008</strong> appeared first on Sea Marconi.

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Scenario

Hydro power plant

Nameplate data of transformer:

Transformer: power transformer
Year: 1948
Power [MVA]: 33
Voltage [KV]: 225
Oil mass [Kg]: 74.000 

Solution Sea Marconi

Solution: Dehydration treatment performed on-load (transformer fully load during the treatment)

Before the treatment

After the treatment

After 6 months
Oil temp. [°C] 15 63 35
Dissolved water [mg/Kg] IEC 60814 28 8 14
Saturation pecentage 62% 3% 13,94%
Water inside the paper using the equilibrium curve > 10% (*) 3,9%
Insulating condition IEC 60422 Extremely wet (*) Moderately wet
Breakdown voltagea [KV] IEC 60156 39,8 > 75 > 75

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