STEAM DEVICE

• US 20110280717A1
• Filed: 05/26/2011
• Published: 11/17/2011
• Est. Priority Date: 11/27/2008
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Suzuki, Yusuke, Saito, Kazuhiro, Inomata, Asako, Nakatani, Yuujiro, Inukai, Takao, Iwai, Shogo, WADA, Kunihiko, Suga, Takeo, Yamashita, Katsuya, Ishiwata, Yutaka
• Granted Patent: US 8,393,861 B2
• Time in Patent Office: Days
• US Class Current: 415/200
• CPC Class Codes: C23C 28/322 only coatings of metal elements only
• CPC Class Codes: C23C 28/324 with at least one metal matrix material layer comprising a mixture of at least two metals or metal phases or a metal-matrix material with hard embedded particles, e.g. WC-Me
• CPC Class Codes: C23C 28/345 with at least one oxide layer
• CPC Class Codes: C23C 28/3455 with a refractory ceramic layer, e.g. refractory metal oxide, ZrO2, rare earth oxides or a thermal barrier system comprising at least one refractory oxide layer
• CPC Class Codes: C23C 28/42 characterized by the composition of the alternating layers
• CPC Class Codes: C23C 30/00 Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process C23C26/00, C23C28/00 take precedence
• CPC Class Codes: F01D 25/007 Preventing corrosion
• CPC Class Codes: F05D 2220/31 in steam turbines
• CPC Class Codes: F05D 2230/90 Coating; Surface treatment
• CPC Class Codes: F05D 2300/504 Reflective properties

Abstract

In one embodiment, a steam device includes a high-temperature member and a low-temperature member. One surface of the high-temperature member is exposed to high-temperature steam, and the other surface is cooled by cooling steam having a temperature lower than the high-temperature steam. The low-temperature member is disposed to face the high-temperature member with a passage for the cooling steam therebetween and is formed of a material having a heat resistance lower than that of the high-temperature member. The steam device has at least one high-reflectance film selected from a first high-reflectance film, which is formed on the surface of the high-temperature member which is exposed to the high-temperature steam and has a higher reflectance with respect to infrared rays than the high-temperature member, and a second high-reflectance film, which is formed on the surface of the low-temperature member facing the high-temperature member and has a higher reflectance with respect to infrared rays than the low-temperature member.

Claims

1. A steam device, comprising:

a first member one side of which is exposed to high-temperature steam and the other side of which is cooled by low-temperature steam having a temperature lower than that of the high-temperature steam; and

a second member which is disposed to face the first member with a passage for the low temperature steam between them and is formed of a material having a heat resistance lower than that of the first member;

at least one of;

a first high-reflectance film which is formed on the surface of the first member exposed to the high-temperature steam and which has a reflectance with respect to infrared rays higher than the first member, and

a second high-reflectance film which is formed on the surface of the second member facing the first member and which has a reflectance with respect to infrared rays higher than the second member.

3. A steam device according to claim 1, further comprising:

a low-emissivity film which is formed on the surface of the first member cooled by the low-temperature steam and which has emissivity lower than the first member.

4. The steam device according to claim 1,

wherein the first and second high-reflectance films have a structure that a low refractive index material layer and a high refractive index material layer, which has a refractive index higher than that of the low refractive index material layer, are laminated.

6. The steam device according to claim 4,

wherein the low refractive index material layer and the high refractive index material layer are formed of a dielectric oxide containing at least one selected from aluminum oxide (Al₂O₃), silicon oxide (SiO₂), gallium oxide (Ga₂O₃), magnesium oxide (MgO), samarium oxide (Sm₂O₃) yttrium oxide (Y₂O₃), zirconium oxide (ZrO₂), nickel oxide (NiO), hafnium oxide (HfO₂), cerium oxide (Ce₂O₃), chromium oxide (Cr₂O₃), niobium oxide (Nb₂O₅), tantalum oxide (Ta₂O₅), tungsten oxide (WO₃), titanium dioxide (TiO₂) and zinc oxide (ZnO), and the low refractive index material layer has a refractive index lower than that of the high refractive index material layer.

7. The steam device according to claim 1,

wherein the first and second high-reflectance films have a structure that a plurality of particles, which have at least two types of dielectric oxide layers having a different refractive index laminated on the surfaces of oxide particles, are bonded by a substance formed of an inorganic or organic material.

9. The steam device according to claim 1,

wherein a film having a thermal conductivity of 5 W/mK or less is laminated on at least one of the first high-reflectance film and the second high-reflectance film.

11. The steam device according to claim 1,

wherein the first and second high-reflectance films are formed of a dense layer having a porosity of 30 or less which has an oxide containing silicon oxide as matrix and contains 20 to 80 vol % of a filler formed of particles of an oxide different from the matrix.

13. The steam device according to claim 11,

wherein the filler has as a main component at least one oxide selected from aluminum oxide (Al₂O₃), zirconium oxide (ZrO₂) and titanium oxide (TiO₂).

14. The steam device according to claim 1,

wherein the first and second high-reflectance films are formed of a dense layer having a porosity of 3% or less which has an oxide containing silicon oxide as matrix and contains 10 to 80 vol % of a filler formed of metal particles.

16. The steam device according to claim 14,

wherein the filler has as a main component at least one selected from aluminum, silver, platinum and gold.

17. The steam device according to claim 11,

wherein the dense layer has emissivity of 0.3 or less or reflectance of 0.7 or more with respect to infrared rays having a wavelength of 2.7 microns.

18. The steam device according to claim 11,

wherein a heat-insulating ceramics layer which has a thermal conductivity lower than that of the dense layer is formed as a lower layer of the dense layer.

19. The steam device according to claim 18,

wherein the heat-insulating ceramics layer has a porosity of 5% to 50%.

20. The steam device according to claim 18,

wherein the heat-insulating ceramics layer is formed of any of zirconium oxide, cerium oxide, hafnium oxide, yttrium oxide, and boride.

21. The steam device according to claim 1,

wherein the first member is a high temperature sleeve of a steam inlet pipe of a steam turbine, and the second member is an inlet pipe casing which surrounds the periphery of the high temperature sleeve.

22. The steam device according to according to claim 1,

wherein the first member is a component member of a nozzle box portion which guides inlet steam of the steam turbine to the turbine portion, and the second member is a turbine rotor which is opposed to a component member of the nozzle box portion.

23. The steam device according to claim 1,

wherein the first member is an inner casing which fixes a nozzle diaphragm of the steam turbine, and the second member is an outer casing which is on the outside of the inner casing.

24. The steam device according to claim 1,

wherein the first or second high-reflectance film is formed on the surface of a heat resistant tile, and the heat resistant tile is fixed to the first or second member.

2. A steam device, comprising:

a first member one side of which is exposed to high-temperature steam and the other side of which is cooled by low-temperature steam having a temperature lower than that of the high-temperature steam;

a second member which is disposed to face the first member with a passage for the low temperature steam between them and is formed of a material having a heat resistance lower than that of the first member; and

a low-emissivity film which is formed on the surface of the first member cooled by the low-temperature steam and which has emissivity lower than the first member.

5. The steam device according to claim 2,

wherein the low-emissivity film has a structure that a low refractive index material layer and a high refractive index material layer, which has a refractive index higher than that of the low refractive index material layer, are laminated.

8. The steam device according to claim 2,

wherein the low-emissivity film has a structure that a plurality of particles, which have at least two types of dielectric oxide layers having a different refractive index laminated on the surfaces of oxide particles, are bonded by a substance formed of an inorganic or organic material.

10. The steam device according to claim 2,

wherein a film having a thermal conductivity of 5 W/mK or less is laminated on the low-emissivity film.

12. The steam device according to claim 2,

wherein the low-emissivity film is formed of a dense layer having a porosity of 3% or less which has an oxide containing silicon oxide as matrix and contains 20 to 80 vol % of a filler formed of particles of an oxide different from the matrix.

15. The steam device according to claim 2,

wherein the low-emissivity film is formed of a dense layer having a porosity of 3% or less which has an oxide containing silicon oxide as matrix and contains 10 to 80 vol % of a filler formed of metal particles.

25. The steam device according to claim 2,

wherein the low-emissivity film is formed on the surface of the heat resistant tile, and the heat resistant tile is fixed to the first member.

26. The steam device according to claim 12,

wherein the filler has as a main component at least one oxide selected from aluminum oxide (Al₂O₃), zirconium dioxide (ZrO₂), and titanium dioxide (TiO₂).

27. The steam device according to claim 15,

wherein the filler has as a main component at least one selected from aluminum, silver, platinum and gold.

28. The steam device according to claim 12,

wherein the dense layer has emissivity of 0.3 or less or reflectance of 0.7 or more with respect to infrared rays having a wavelength of 2.7 microns.

29. The steam device according to claim 12,

wherein a heat-insulating ceramics layer having a thermal conductivity lower than that of the dense layer is formed as a lower layer of the dense layer.

30. The steam device according to claim 29,

wherein the heat-insulating ceramics layer has a porosity of 5% to 50%.