TRAFOSEAL
TRAFOSEAL: Technical Specifications
What Is a TRAFOSEAL ?
The TRAFOSEAL represents a new art of the hermetization of power oil-immersed transformers by means of a natural physical phenomenon so-called thermal stratification layer in the oil which is spontaneously created as a "interface" between the hot oil (the main tank oil inventory) and the cold oil (the conservator oil inventory).
FIG.1 Schematical lay-out of TRAFOSEAL II
The thermal stratification layer is generally situated in the TRAFOSEAL tank , which bottom part is hydraulicaly connected to the bottom part of the conservator and its upper part is interconnected with the oil invetory of the main tank.
The thermal stratification layer - behaves itself as a horizontal and a very thin and virtually undestructible membrane which divides the hot oil in the upper part of the TRAFOSEAL tank and the cold oil in its bottom part (See Fig. 1) and avoids very effectively the free mixing of cold, gas and water contaminated oil from the conservator, with the hot oil from the main tank which is protected against external contamination that way.
Under normal operational conditions the temperature of the oil inventory of the power transformer steadily varies and consequently varies the oil volume in the main tank.
By the temperature increase is the oil from the main tankforced into upper part of the TRAFOSEAL tank, the thermal stratification layer moves downward and the cold oil from the bottom part of the TRAFOSEAL tank is consequently forced in the conservator.
On the other hand by the decrease of the transformer temperature, the oil volume in the main tank decreases, the hot oil from the upper part of TRAFOSEAL tank flows back into the main tank, the stratification layer moves upward and the bottom part of the TRAFOSEAL tank is filled with the cold oil from the conservator .
For more detailed insight into the dynamic behaviour of the TRAFOSEAL II, See Dynamic Animation.
For quantitative verification of the TRAFOSEAL II function See article:
- The quantitative verification of the TRAFOSEAL II [PDF]
- and/or
Beurteilung des Hermetisierung mit TRAFOSEAL [PDF]
For basic comparison of present hermetizations methods of power transformers See Comparison of hermetization methods of power transformers [PDF]
For a more detailed explanation of a long-term stabilisation of the stratification layer in the TRAFOSEAL tank, the transformer protection etc. See: US Patent No.: 7,122,075 B2.
For detailed design and the real lay-out of the TRAFOSEAL II
See The Infrared verification
( http://www.ars-altmann.com/pubdoc/infrared_verification.pdf )