GB2267329A - Thermal insulation structure - Google Patents
Thermal insulation structure Download PDFInfo
- Publication number
- GB2267329A GB2267329A GB9210308A GB9210308A GB2267329A GB 2267329 A GB2267329 A GB 2267329A GB 9210308 A GB9210308 A GB 9210308A GB 9210308 A GB9210308 A GB 9210308A GB 2267329 A GB2267329 A GB 2267329A
- Authority
- GB
- United Kingdom
- Prior art keywords
- thermal insulation
- insulation structure
- skins
- skin
- blankets
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000009413 insulation Methods 0.000 title claims abstract description 19
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 16
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 8
- 239000012528 membrane Substances 0.000 claims abstract description 7
- 239000005030 aluminium foil Substances 0.000 claims abstract description 4
- 239000011810 insulating material Substances 0.000 claims description 8
- 239000011888 foil Substances 0.000 claims description 5
- 230000004888 barrier function Effects 0.000 abstract description 3
- 239000007789 gas Substances 0.000 description 9
- 239000000567 combustion gas Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 239000012774 insulation material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
- F01D25/08—Cooling; Heating; Heat-insulation
- F01D25/14—Casings modified therefor
- F01D25/145—Thermally insulated casings
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
- F02C7/00—Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
- F02C7/24—Heat or noise insulation
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L59/00—Thermal insulation in general
- F16L59/02—Shape or form of insulating materials, with or without coverings integral with the insulating materials
- F16L59/026—Mattresses, mats, blankets or the like
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L59/00—Thermal insulation in general
- F16L59/08—Means for preventing radiation, e.g. with metal foil
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Thermal Insulation (AREA)
Abstract
Insulating blankets 30 are inserted between a turbine casing 28 and a platform 26 of a nozzle guide vane 24. The insulation blankets 30 comprise an aluminium foil skin 32 which encapsulates silica fibres 31. The abutting surfaces 33 of the blankets 30 are reflective and have undulations therein which define an air gap 34 between the surfaces 33. The air gap acts as an additional thermal barrier and the surfaces 33 reflect any radiant heat to improve the thermal insulation effectiveness of the blankets 30. In an alternative embodiment (see Fig 3) a single insulating blanket (30) having an internal heat reflecting membrane <IMAGE>
Description
THERMAL INSULATION STRUCTURE
The present invention relates to a thermal insulation structure particularly but not exclusively for insulating a hot gas stream of a gas turbine engine from adjacent structure.
There are a number of different areas in gas turbine engines in which it is necessary to insulate the surrounding structures from the effects of the hot gas stream. This is particularly the case in the turbine and exhaust regions of the engine.
Turbine casings are insulated from the hot turbine gases by inserting insulation material between the turbine casing and the vane platforms and rotor segments. Soft silica fibres are used which have been found to erode through turbine gas leaks which leads to deterioration of their insulating capabilities.
It is known to encapsulate fibrous insulating materials such as silica fibres in an outer skin of stainless steel. The stainless steel casing prevents erosion of the fibrous insulating material and also prevents the fibres which are porous from absorbing unburned fuel.
The present invention seeks to provide a structure which has improved thermal insulating capabilities.
According to one aspect of the present invention a thermal insulation structure comprises an at least one skin capable of withstanding heat, the at least one skin defining a chamber which encloses a fibrous insulating material, there being provided an at least one reflective membrane within the chamber which acts as a heat shield to reflect radiant heat.
The reflective membrane may be made from a metallic foil. Preferably a plurality of skins are arranged in abutting relationship, the abutting surfaces of each skin being reflective to act as a heat shield and reflect radiant heat.
According to a further aspect of the present invention a thermal insulating structure comprises a plurality of skins which are capable of withstanding heat, each skin defining a chamber which encloses a fibrous insulating material, the skins being arranged in abutting relationship so that the abutting surface of each skin is reflective to act as a heat shield and reflect radiant heat.
Preferably the abutting surfaces of the skins have undulations therein to provide an air gap between the surfaces which acts as an additional thermal barrier. The skins are preferably made from aluminium foil of the order of 0.0254mm thick. The fibrous insulating material is preferably made from silica fibres.
The present invention will now be described with reference to the accompanying drawings in which;
Figure 1 is a schematic view of a gas turbine engine incorporating a heat insulating structure in accordance with the present invention.
Figure 2 is an enlarged view of part of the turbine section of the engine shown in figure 1 incorporating a heat insulating structure in accordance with one embodiment of the present invention.
Figure 3 is a cross-sectional view of a heat insulating structure in accordance with a second embodiment of the present invention.
Referring to figure 1 a gas turbine engine generally indicated at 10 comprises a fan 12, a compressor 14, combustion equipment 16 and a turbine 18 in axial flow series. The engine 10 operates in conventional manner so that the air is compressed by the fan 12 and compressor 14 before being mixed with fuel and the mixture combusted in the combustion equipment 16. The hot combustion gases then expand through the turbine 18, which drives the fan 12 and the compressor 14 before exhausting through the exhaust nozzle 20.
The hot combustion gases are directed by nozzle guide vanes 24 onto rows of turbine blades 22 which rotate and extract energy from the hot combustion gases. The continuous flow of gas to which the turbine 18 is exposed may have an entry temperature of between 850 and 1700 C.
The nozzle guide vanes 24 are located in turbine casing 28 so that they can expand under these severe temperatures.
Heat transfer to the turbine casing 28 is limited by the inclusion of insulating blankets 30 between platform 26 of the nozzle guide vanes 24 and the turbine casing 28.
The insulation blanket 30 is a soft silica fibre material 31 which is encapsulated in a thin foil skin 32.
In the embodiment of the present invention shown in figure 2 two blankets 30 are inserted between the nozzle platform 26 and the turbine casing 28. The surfaces 33 of the skin 32 which abut one another are corrugated or cross corrugated to achieve an air gap 34 between the blankets 30. The corrugations in the surfaces 33 also absorb distortions arising from differential expansion and assembly. The air gap 34 and the surfaces 33 act as an additional thermal barrier further insulating the platform 26 of the nozzle guide vane 24 from the turbine casing 28.
The surfaces 33 are reflective and act as a heat shield to reflect any radiant heat.
If the cavity between the platform 26 of the nozzle guide 24 and the turbine casing 28 are narrow then a single insulating blanket 30 is used (figure 3). The soft silica fibres 31 are encapsulated in a thin foil skin 32 which is provided with an internal foil membrane 35. The internal membrane 35 acts as a heat shield to reflect any radiant heat.
In the preferred embodiment of the present invention the skin 32 is an aluminium foil of the order of 0.0254mm thick. The thin section of the skin 32 allows it to be deformed to the contours of the cavity during assembly.
The silica fibre material 31 completely fill the skins 32 so that the blankets 30 maintain their shape and to eliminate any hot air convection currents within the skins 32.
The blankets 30 in accordance with the present invention improve the effectiveness of the thermal insulation which allows the turbine casing 28 to be made from materials which are less heat resistant than the nickel based alloys presently used.
It will be appreciated by one skilled in the art that although the insulation blankets 30 have been described for use between the platform 26 of a nozzle guide vane 24 and the turbine casing 28 that they could be used between rotor segments and the turbine casing 28 or in other sections of the engine 10 such as the exhaust nozzle 20.
Claims (10)
1. A thermal insulation structure comprising an at least one skin capable of withstanding heat, the at least one skin defining a chamber which encloses a fibrous insulating material, there being provided an at least one reflective membrane within the chamber which acts as a heat shield to reflect radiant heat.
2. A thermal insulation structure as claimed in claim 1 in which the reflective membrane is made from a metallic foil.
3. A thermal insulation structure as claimed in claim 1 or claim 2 in which a plurality of skins are arranged in abutting relationship, the abutting surfaces of each skin being reflective to act as a heat shield to reflect radiant heat.
4. A thermal insulation structure comprising a plurality of skins which are capable of withstanding heat, each skin defining a chamber which encloses a fibrous insulating material, the skins being arranged in abutting relationship so that the abutting surface of each skin is reflective to act as a heat shield to reflect radiant heat.
5. A thermal insulation structure as claimed in claim 3 or claim 4 in which the abutting surfaces of the skins have undulations therein to define an air gap between the surfaces.
6. A thermal insulation structure as claimed in any preceding claim in which the skins are made from aluminium foil.
7. A thermal insulation structure as claimed in any preceding claim in which the skins are of the order of 0.0254mm thick.
8. A thermal insulation structure as claimed in any preceding claim in which the fibrous insulating material is made from silica fibres.
9. A thermal insulation structure as hereinbefore described with reference to and as shown in figures 1 and 2.
10. A thermal insulation structure as hereinbefore described with reference to and as shown in figures 1 and 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9210308A GB2267329A (en) | 1992-05-14 | 1992-05-14 | Thermal insulation structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9210308A GB2267329A (en) | 1992-05-14 | 1992-05-14 | Thermal insulation structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9210308D0 GB9210308D0 (en) | 1992-07-01 |
| GB2267329A true GB2267329A (en) | 1993-12-01 |
Family
ID=10715465
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9210308A Withdrawn GB2267329A (en) | 1992-05-14 | 1992-05-14 | Thermal insulation structure |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2267329A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7654239B2 (en) * | 2001-12-20 | 2010-02-02 | American Diesel & Gas, Inc. | Fuel saving combustion engine insulation method and system |
| EP2570620A1 (en) * | 2011-09-15 | 2013-03-20 | Siemens Aktiengesellschaft | Thermal insulation for a turbine housing |
| FR3072999A1 (en) * | 2017-10-31 | 2019-05-03 | Safran Aircraft Engines | THERMAL SCREEN FOR TURBOMACHINE AND METHOD OF MANUFACTURE |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1300390A (en) * | 1969-08-12 | 1972-12-20 | Atomic Energy Authority Uk | Improvements in or relating to thermal insulation |
| GB2121159A (en) * | 1982-05-25 | 1983-12-14 | Bbc Brown Boveri & Cie | A heat insulating device |
| EP0184415A1 (en) * | 1984-12-04 | 1986-06-11 | Nippon Sanso Kabushiki Kaisha | Evacuated heat insulation unit |
| US5030518A (en) * | 1987-12-09 | 1991-07-09 | Messerschmitt-Boelkow-Blohm Gmbh | Multi-layer thermal insulation, especially for spacecraft |
-
1992
- 1992-05-14 GB GB9210308A patent/GB2267329A/en not_active Withdrawn
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1300390A (en) * | 1969-08-12 | 1972-12-20 | Atomic Energy Authority Uk | Improvements in or relating to thermal insulation |
| GB2121159A (en) * | 1982-05-25 | 1983-12-14 | Bbc Brown Boveri & Cie | A heat insulating device |
| EP0184415A1 (en) * | 1984-12-04 | 1986-06-11 | Nippon Sanso Kabushiki Kaisha | Evacuated heat insulation unit |
| US5030518A (en) * | 1987-12-09 | 1991-07-09 | Messerschmitt-Boelkow-Blohm Gmbh | Multi-layer thermal insulation, especially for spacecraft |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7654239B2 (en) * | 2001-12-20 | 2010-02-02 | American Diesel & Gas, Inc. | Fuel saving combustion engine insulation method and system |
| EP2570620A1 (en) * | 2011-09-15 | 2013-03-20 | Siemens Aktiengesellschaft | Thermal insulation for a turbine housing |
| FR3072999A1 (en) * | 2017-10-31 | 2019-05-03 | Safran Aircraft Engines | THERMAL SCREEN FOR TURBOMACHINE AND METHOD OF MANUFACTURE |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9210308D0 (en) | 1992-07-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1407193B1 (en) | Coolable segment for a turbomachinery and combustion turbine | |
| RU2310795C2 (en) | Gas turbine with combustion chamber made of composite material | |
| US5027604A (en) | Hot gas overheat protection device for gas turbine engines | |
| US5598697A (en) | Double wall construction for a gas turbine combustion chamber | |
| EP0471437B1 (en) | Gas turbine engine combustor | |
| JP4167394B2 (en) | Combustor and steam cooling method thereof | |
| US5012645A (en) | Combustor liner construction for gas turbine engine | |
| GB2220711A (en) | Stator assembly for a gas turbine engine | |
| US5749229A (en) | Thermal spreading combustor liner | |
| US5899660A (en) | Gas turbine engine casing | |
| US5104286A (en) | Recirculation seal for a gas turbine exhaust diffuser | |
| US6135715A (en) | Tip insulated airfoil | |
| GB2239679A (en) | Self-cooling joint connection for abutting segments in a gas turbine engine | |
| US5662457A (en) | Heat insulation assembly | |
| GB2317005A (en) | Combustion chamber | |
| US20100272953A1 (en) | Cooled hybrid structure for gas turbine engine and method for the fabrication thereof | |
| GB2104965A (en) | Multiple-impingement cooled structure | |
| GB2450405A (en) | Gas turbine nozzle with differently cooled vanes | |
| US5176495A (en) | Thermal shielding apparatus or radiositor for a gas turbine engine | |
| CA2366184A1 (en) | Gas turbine blade/vane and gas turbine | |
| US20100068069A1 (en) | Turbine Blade | |
| US5085038A (en) | Gas turbine engine | |
| US4300349A (en) | Gas turbine with heat-insulating lining | |
| EP0522795B1 (en) | Heat shield | |
| GB2267329A (en) | Thermal insulation structure |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |