Scenario
Hydro power plant with 3 GSU transformers
Nameplate data of the transformer:
Manufacturer: xxx
Year: 1965
Power [MVA]: 80
Voltage [KV]: 220
Oil mass [Kg]: 35.000
Oil type: naphthenic blended
Solution
Selective deplarization treatment (Chedcos) in order to remove the corrosive sulfur compounds and dehalogenation treatments (CDP Process®) in order to remove the PCBs from the oil and the transformers. the tratments were performed on-site and on-load (transformer in service and fully load during the treatment).
Before the treatment |
After the treatment |
|
| PCB* [mg/Kg] | 96 | 26 |
| TCS (total corrosive sulfur) DBDS Eq. [mg/Kg] | 64 | < 10 |
| CCD | Corrosivw | NOT Corrosive |
| DBTP [mg/Kg] | 16 | 14 |
| TAN [mg KOH/g] | 0,194 | 0 |
| TgD | 0,03737 | 0,05144 |
*The agreed guarantee was PCBs < 50 [mg/Kg]
