Original scientific paper
CFD SIMULATION OF PRESSURE LOSS IN HVDC TRANSFORMER WINDING
Ralf Wittmaack
; Siemens AG, Nürnberg, Germany
Abstract
At Siemens the in-house CFD code UniFlow is used to analyse fluid flow and heat transfer in oilimmersed
and dry-type transformers, as well as transformer components like windings, cores, tank walls,
and radiators. It can be employed to perform steady state as well as transient analyses. This paper
describes its physical models and numerical solution methods.
Moreover, it presents an application to a valve winding of a HVDC transformer, cooled by mineral
oil. This study is aimed at finding the flow induced pressure loss in the winding and the static ring
assembly below and above the winding. The investigation includes isothermal runs with different inlet
velocity and a conjugate heat transfer run with a conductor representation.
In the isothermal simulations a steady state is established and the pressure loss is an almost
linear function of the inlet velocity. In the run involving heat transfer, the high buoyancy forces hamper the
development of a steady state and the possibility to calculate a flow induced pressure loss.
Keywords
Thermal design; CFD; pressure loss; physical models; numerical methods
Hrčak ID:
199246
URI
Publication date:
15.8.2017.
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