Abstract
Retrofilling transformers with a new liquid has been considered as an option for life extension and/or uprating purposes. The determination of the new total liquid flow rate is of vital importance in assessing the effect of retrofilling on flow and temperature distributions in the winding, especially for ON transformers. This paper presents the determination of flow rate ratios for four liquids—a mineral oil, a GTL oil, a synthetic ester and a natural ester—in ON transformer retrofilling scenarios. Flow rate ratios among different liquids are provided for a simplified condition of linear radiator oil temperature variation. For a more realistic exponential radiator oil temperature variation, the detailed transformer geometric information is needed to estimate the total flow rate. In addition, a hydraulic winding network model is established to prove that “minor pressure losses” due to change of flow directions is indeed minor for ON transformer liquid flow conditions, justifying neglecting the minor losses in the deduction of the total liquid flow rate.
| Original language | English |
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| Title of host publication | International Conference on Dielectric Liquids (ICDL) |
| Publication status | Published - 27 Jun 2019 |
| Event | 2019 IEEE International Conference on Dielectric Liquids - Rome, Italy Duration: 23 Jun 2019 → 27 Jun 2019 |
Conference
| Conference | 2019 IEEE International Conference on Dielectric Liquids |
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| Abbreviated title | IEEE ICDL 2019 |
| Country/Territory | Italy |
| City | Rome |
| Period | 23/06/19 → 27/06/19 |
Keywords
- ester
- flow rate
- GTL
- Mineral oil
- retrofilling
- transformer