ISSN Online: 2377-424X
ISBN Print: 978-1-56700-421-2
International Heat Transfer Conference 15
Numerical Study of on Cooling Performance for Multi-holes Steam Jet in the Internal Channel of a Hollow Turbine Blade
Résumé
Advanced cooling technology, which is one of the major thermal protection methods of turbine blade, can
improve turbine inlet temperature significantly. Using closed internal steam cooling for turbine blade can
reduce compressor air consumption, decrease mixing loss caused by cooling air entering the mainstream
passage. In contrast to air, superheated steam has higher specific heat and better cooling capacity, and thus it
can yield higher cooling performance. A numerical study was performed in this paper to investigate the flow
and heat transfer of steam jet impingement cooling. First, referring to experiment results of previous single
air jet impingement, steam impingement cooling of single jet hole was numerically simulated. The influence
of jet diameter, the nozzle-to-surface distance on the heat transfer characteristics was obtained. Following, a
new cooling structure which used steam jet impingement cooling at a turbine guide vane was purposed.
Numerical calculated was performed to study its cooling performance, compared with that of the test blade
of five internal cooling smooth channels. The results show that steam jet impingement cooling can achieve
impressive cooling effectiveness at the whole surface of the blade. Thus it can replace film cooling, simplify
vane cooling structure, and enhance turbine efficiency.