Rotary kinetic fluid motors or pumps – With passage in blade – vane – shaft or rotary distributor...
Reexamination Certificate
2002-05-22
2003-12-09
Look, Edward K. (Department: 3745)
Rotary kinetic fluid motors or pumps
With passage in blade, vane, shaft or rotary distributor...
Reexamination Certificate
active
06659714
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a device for a component to be cooled, upstream of which is arranged a baffle-cooling plate capable of being acted upon by a coolant and having a coolant leadthrough. A diversion duct for the coolant is provided, next to the coolant leadthrough, between the baffle-cooling plate and the component to be cooled.
BACKGROUND OF THE INVENTION
In a thermal machine, for example in a gas or steam turbine, the surfaces delimiting a space are subjected to high thermal load by a hot medium, for example a hot gas or steam. With a view to increasing the efficiency of the thermal machine, attempts are made, inter alia, to achieve as high a temperature of the hot medium as possible. On the one hand, therefore, it is of great importance to find suitable materials for the surfaces acted upon by the hot medium, especially materials with sufficient strength at as high temperatures as possible. On the other hand, it is important to cool these surfaces efficiently, so that high temperatures can be applied. In a gas turbine, the coolant necessary for cooling is conventionally extracted as cooling air from a compressor coupled to the turbine. In order to keep the efficiency loss accompanying this cooling-air extraction as low as possible, an intensive search for cooling concepts ensuring as efficient a use of coolant as possible is being conducted.
DE 26 28 807 A1 describes a baffle-cooling system for a turbine moving blade. The turbine moving blade comprises a blade root for fastening to a rotor of the turbine, a blade leaf for flow around by a working medium and a platform for delimiting a duct for the working medium. In the case of a gas turbine, very high temperatures occur in the duct, so that the platform surface exposed to the hot working medium is subjected to high thermal load. For cooling the platform, therefore, a perforated wall element, designated as a baffle-cooling plate, is arranged upstream of the side facing away from the hot working medium. A coolant passes through recesses (coolant leadthroughs) in the baffle-cooling plate and impinges onto that side of the platform which faces away from the working medium. Cooling of the platform is thereby achieved.
A coolable stator group for a gas turbine power plant may be gathered from U.S. Pat. No. 4,642,024. The stator group has an external air seal and also an upstream holder and a downstream holder. The holders support the external air seal with the aid of hook catches over a flow path of a hot working medium. The air seal is thereby divided structurally in three into a downstream and an upstream edge region and a central region arranged between the edge regions. For cooling the external air seal using cooling air, there is, first of all, baffle cooling in the central region. The edge regions, which cannot be acted upon directly by cooling air on account of the holders, are cooled by some of the collected cooling air being led through the holders, in order to allow a baffle cooling of the edge regions. For this purpose, metering holes extend through the holders, in order to guide the cooling air onto the upstream and the downstream edge region for the baffle cooling of the edge regions.
An improved cooling arrangement for guide rings of turbine guide blades in the gas turbine may be gathered from U.S. Pat. No. 5,649,806. A guide ring is arranged as a wall element in a gas turbine between the platforms of two turbine guide blades. The outer surface of the guide ring is exposed to the hot gas and is spaced in the radial direction from the outer ends of the turbine moving blades by a gap. A discharge of heat by convective cooling and by baffle cooling becomes possible through cooling ducts within the guide ring wall exposed to the hot gas.
Furthermore, the guide ring has cooling-air slots specially configured in relation to the outer surface. These are oriented in such a way that the cooling air is led in the direction of flow of the hot gas onto the outer surface with minimal movement exchange between the cooling air and the hot gas. Film cooling of the surface exposed to the hot gas is thereby brought about.
A baffle-cooling device for an aircraft engine component, for example a compressor part of an aircraft engine, may be gathered from EP 0 624 757 A1. The baffle-cooling device comprises a corrugated plate with a multiplicity of wave crests extending parallel to a preferential axis and wave troughs adjacent to these, which in each case have a trapezoidal contour. The wave troughs are provided, here, with baffle-cooling bores. The wave troughs and wave crests form cooling ducts which extend parallel to the preferential axis and are flow-connected to the compressor part. Weblike distributor plates are arranged perpendicularly to the preferential axis, the distributor plates in each case being connected at their upper edge to the perforated corrugated plate and at their lower edge to the compressor outlet tube. By use of the distributor plates, after a baffle cooling of the compressor tube the air is first guided perpendicularly to the preferential axis and is thereafter distributed to the cooling ducts. A feedback or intermixing of already diverted air with the air supplied for baffle cooling is thereby likewise to be prevented.
A baffle-cooling device with a perforated uniaxial corrugated plate of trapezoidal configuration, similar to that in EP 0 624 757 A1, is described in U.S. Pat. No. 5,467,815. Here, the baffle-cooling plate is arranged, spaced, opposite a wall, to be cooled, of a combustion chamber. After a baffle cooling of the wall by means of cooling air, the air passes into regions of the wave crests having an enlarged flow cross section, where the air is led further on along the axis. This does not prevent influence from being exerted on baffle-cooling air from baffle-cooling holes adjacent to one another, since an unimpeded overflow is possible.
SUMMARY OF THE INVENTION
An object of the invention is to create an improved device for a component to be cooled, with a baffle-cooling plate capable of being acted upon by a coolant. In one embodiment, the device is intended to bring about improved baffle cooling for the component to be cooled and to allow a more efficient use of coolant.
This object is achieved, according to one embodiment of the invention, by a device for a component to be cooled, with a baffle-cooling plate capable of being acted upon by a coolant and having a coolant leadthrough. In one embodiment, the baffle-coolant plate can be arranged upstream of the component to be cooled, and a diversion duct for the coolant can be provided, next to the coolant leadthrough, between the baffle-cooling plate and the component to be cooled. Further, the baffle-cooling plate can include a further coolant leadthrough, with the diversion duct including a flow barrier for the coolant between the coolant leadthrough and the further coolant leadthrough.
In baffle cooling, normally, a coolant is guided through a multiplicity of coolant leadthroughs in a panel or plate (baffle-cooling plate) which is adjacent to the surface, to be cooled, of the component to be cooled. Consequently, the coolant impinges in a corresponding multiplicity of coolant jets essentially perpendicularly onto the surface to be cooled. During interaction with a surface to be cooled, the coolant absorbs heat which, as a result of heat transfer, is transmitted from the component subjected to thermal load to the coolant. As a result of this interaction, the coolant is heated up. The cooling efficiency in the case of baffle cooling is higher than, for example, in conventional convection cooling, in which the coolant is led essentially parallel to the component surface to be cooled. Effective cooling of the component is achieved by baffle cooling. The component can thereby be exposed to higher temperatures, since, with the same introduction of heat into the component, the component can be maintained at a lower material temperature, as compared with other cooling methods.
An embodiment of the invention proceeds from the
Look Edward K.
McCoy Kimya N
LandOfFree
Baffle cooling device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Baffle cooling device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Baffle cooling device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3174042