Browse Prior Art Database

Turbine Nozzle Cast Trailing Edge Impingement Cavity

IP.com Disclosure Number: IPCOM000201688D
Original Publication Date: 2010-Nov-18
Included in the Prior Art Database: 2010-Nov-18
Document File: 9 page(s) / 928K

Publishing Venue

Siemens

Related People

Juergen Carstens: CONTACT

Abstract

Internal cooling passages have long been used in industrial and aero gas turbines nozzle and blade aerofoils. They give thinner walled sections and improve the heat transfer of the components. The thin walls are achieved by casting the aerofoil sections with an internal core. The trailing edge of hot gas path components is a difficult area to cool due to the difficulty in providing a path for cooling air to this region. Typically cooling has been from impingement of air onto the inner platform surface. However, due to the thickness of platform section this is not always totally successful. Ineffective or insufficient supply of cooling can lead to the components overheating and cause premature failure of components, which in turn causes damage to other turbine components and costly unplanned maintenance. Currently to optimize the use of cooling air further, holes are manufactured through the platform surface in order to allow flow of cooling air from a high pressure (cool) area to a lower pressure (hotter) area. Sometimes these holes are fanned to “spread” the cooling air further over the surfaces.

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Turbine Nozzle Cast Trailing Edge Impingement Cavity

Idea: Paul Headland, GB-Lincoln; Tont Davis, GB-Lincoln; Paul Jenkinson, GB-Lincoln; Charlotte

                                              nozzle and blade mponents. The thin e of hot gas path for cooling air to this surface. However, tive or insufficient ilure of
nts, which in turn causes damage to other turbine components and costly unplanned
ctured through the area to a lower
g air further over the

     cast passages in ssage gives a ally when this is
f the passages. The

platform surface and rm of a nozzle where hich are part of the

Figure 3. It runs llow for inter

destals can be seen in figure 4 below. These could be a mixture of full pedestals and
the two surfaces.

a number of single mum use of the air.

                                             webs can be used ate several discrete pockets in the cavity. The walls can be at an angle to guide the air iment is shown in

               ssages can be manufactured using an EDM (Electrical Discharge Machining) process to form the holes, shown in Figure 8 is a two hole layout but this can be a single or multiple holes. The air will be ejected form the EDM slot via a number of holes or slots as shown in Figure 5.

The cast cavity concept can be applied to the nozzle outer platform trailing edge or the inner platform of a turbine blade.

The proposed novel solution improves the cooling air efficiency and reduces the temperatures of the hot metal, which results in a reduction in total cooling air requirements. Furthermore, the engine efficiency will be improved. Through increased component life and reduced service/repair costs, the over all costs can be reduced.

© SIEMENS AG 2010 file: 2010J18897.doc page: 1

Poole, GB-Lincoln

Internal cooling passages have long been used in industrial and aero gas turbines aerofoils. They give thinner walled sections and improve the heat transfer of the co walls are achieved by casting the aerofoil sections with an internal core. The trailing edg path components is a difficult area to cool due to the difficulty in providing a
region. Typically cooling has been from impingement of air onto the inner platform
due to the thickness of platform section this is not always totally successful. Ineffec supply of cooling can lead to the components overheating and cause premature fa compone
maintenance. Currently to optimize the use of cooling air further, holes are manufa platform surface in order to allow flow of cooling air from a high pressure (cool) pressure (hotter) area. Sometimes these holes are fanned to "spread" the coolin surfaces.

The idea to solve these problems is to combine the use of impingement cooling and the trailing edge of the nozzle/blade. The use of impingement cooling and a cast pa significant improvement in the heat transfer properties at the trailing edge, especi combined with dimples/pimples and walls/webs to increase the surface area o solution also uses holes or slots in the platfo...