Water cooling wall for ultrahigh parameter boiler

Abstract

The invention discloses a water cooling wall for an ultrahigh-parameter boiler, which relates to the technical field of power station boilers and comprises a low-temperature area membrane type wall tube panel assembly, a high-temperature area membrane type wall tube panel assembly and a material transition area positioned between the low-temperature area membrane type wall tube panel assembly and the high-temperature area membrane type wall tube panel assembly, the top of the high-temperature area membrane type wall tube panel assembly is a tube panel outlet area, and the material grade of the low-temperature area membrane type wall tube panel assembly is lower than that of the high-temperature area membrane type wall tube panel assembly; the low-temperature area membrane type wall tube panel assembly comprises a plurality of low-temperature area membrane type wall tube panels which are arranged in parallel; the high-temperature area membrane type wall tube panel assembly comprises a plurality of high-temperature area membrane type wall tube panels arranged side by side and a temperature monitoring system. The design is reasonable, and the field installation heat treatment problem of high-grade materials can be reduced. And meanwhile, the overall stress level of the tube panel is effectively reduced, and the tube panel is prevented from being cracked. The requirement for improving parameter and efficiency of the boiler is met, and the method adapts to the current operation mode of a thermal power generating unit.

Description

Technical Field

[0001] The present invention relates to the technical field of power station boilers, and more specifically to the technical field of water-cooled walls for ultra-high parameter boilers. Background Art

[0002] The parameters of ultra-supercritical boilers of current large-scale power station units are constantly improving, and the design parameters of water-cooled walls are also further improved. The current water-cooled walls are made of conventional carbon steel and low-alloy steel materials (such as 20G, 12Cr1MoVG, etc.), which cannot meet the safety requirements of high parameters for materials. It is necessary to use higher-grade materials (such as SA213T91 or T92 materials) to manufacture water-cooled walls. According to the current conventional technical solution, simply upgrading the materials requires adding a heat treatment process after welding. Heat treatment under on-site installation conditions is difficult and the quality is difficult to guarantee. If the materials at the on-site splicing position are replaced with materials that do not require post-weld heat treatment, the thermal stress will increase due to the different expansion rates of the materials, increasing the risk of cracking after operation. It is even more difficult to cope with the current situation where thermal power units frequently participate in peak regulation. The membrane water-cooled wall has become a bottleneck problem for the improvement of parameters of today's power generation units.

[0003] The main direction to improve unit efficiency is to improve unit parameters. Mature and reliable membrane walls made of low-grade materials cannot meet the strength requirements of water-cooled walls of high-parameter boilers. Due to the nature of the material itself, membrane walls made of high-grade materials have a higher overall stress level and are more prone to cracking and other damage during operation. At the same time, they are more difficult to install. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned technical problems. The present invention provides a water-cooled wall for ultra-high parameter boilers. By proposing a water-cooled wall arrangement and a matching temperature monitoring system, the problem of heat treatment of high-grade materials during on-site installation can be avoided, and the temperature distribution of the tube screen can be effectively controlled to reduce the overall stress level of the tube screen, thereby avoiding the occurrence of tube screen cracking. It not only meets the needs of improving boiler parameters and efficiency, but also adapts to the current operating mode of thermal power units. In this way, the bottleneck problem of water-cooled walls of thermal power boilers with higher parameters is broken through, and while improving the efficiency of the unit, it is also more adapted to the operating characteristics of current thermal power units.

[0005] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0006] The present invention provides a water-cooled wall for an ultra-high parameter boiler, comprising a low-temperature region membrane wall tube panel assembly, a high-temperature region membrane wall tube panel assembly, and a material transition zone between the low-temperature region membrane wall tube panel assembly and the high-temperature region membrane wall tube panel assembly, wherein the top of the high-temperature region membrane wall tube panel assembly is a tube panel outlet area, a monitoring system is provided in the tube panel outlet area, the bottom of the low-temperature region membrane wall tube panel assembly is a tube panel inlet area, a regulating device is provided in the tube panel inlet area, and the material grade of the low-temperature region membrane wall tube panel assembly is lower than that of the high-temperature region membrane wall tube panel assembly;

[0007] The low-temperature region membrane-wall tube-screen assembly includes a plurality of low-temperature region membrane-wall tube-screens arranged in parallel; the high-temperature region membrane-wall tube-screen assembly includes a plurality of high-temperature region membrane-wall tube-screens arranged in parallel.

[0008] Specifically, the water-cooled wall of this scheme is a membrane wall tube screen. The membrane wall tube screen in the low temperature area is compared with the membrane wall tube screen in the high temperature area. The membrane wall tube screen in the high temperature area uses higher grade materials, and there is a material transition between the membrane wall tube screen in the high temperature area and the membrane wall tube screen in the low temperature area. The number of material types and the number of screens in the scheme are determined according to the furnace type and actual parameters.

[0009] Due to performance limitations, low-grade materials cannot meet the safety requirements of 630℃ ultra-high parameter boiler water-cooled walls. This type of water-cooled wall can improve the membrane wall material while ensuring safety. The water-cooled wall material proposed in the present invention is flexible in selection, and can be combined according to different parameters. With the heat-free treatment and anti-cracking structure, it can meet the needs of boilers with higher parameters such as 650℃ and 700℃.

[0010] In one embodiment, the material transition zone adopts a staggered material interface.

[0011] Specifically, the material transition zone adopts a staggered material interface (see Figure 2 ) to make the regional material stress uniform; at the same time, a low stress structure is used for transition (attached Figure 3 ) to reduce the thermal stress caused by the expansion difference at the interface of dissimilar steels.

[0012] In one embodiment, two adjacent low-temperature zone membrane wall tube panels are assembled by welding.

[0013] Specifically, the membrane wall tube screen components in the low temperature area are welded and assembled in a conventional manner without the need for heat treatment.

[0014] In one embodiment, there is a construction site panel assembly joint between two adjacent high temperature area membrane wall tube panels, the two adjacent high temperature area membrane wall tube panels are connected by a composite flexible structure, and the fin flat steel between the two adjacent high temperature area membrane wall tube panels is not welded.

[0015] Specifically, the joints of the membrane wall tube screens in each high-temperature area are connected by a composite flexible structure (see Appendix Figure 4 ), the fin flat steel between the two screens is not welded.

[0016] In one embodiment, a plurality of distributed tie bolt structures are arranged at equal intervals from top to bottom between two adjacent high-temperature region membrane wall tube panels.

[0017] Specifically, multiple distributed tie bolt structures are used for local reinforcement to increase the integrity of the water-cooled wall (see Appendix Figure 6 ).

[0018] In one embodiment, a header docked with the high-temperature region membrane wall tube panel assembly is provided on the top of the high-temperature region membrane wall tube panel assembly, and multiple anti-cracks for reducing end stress are provided at the docking point between the top of the high-temperature region membrane wall tube panel and the header.

[0019] Specifically, in order to improve boiler efficiency, the drum boiler gradually developed into a tubular boiler to increase the heat transfer area. The boiler water flows from the drum through the downcomer into the box below, and is distributed to each tube bundle by the box. The water in these tube bundles continuously absorbs heat energy, gathers in the box above, and then flows back into the drum. The upper and lower boxes are called headers or headers.

[0020] In the high temperature area, the membrane wall tube screen assembly and the header are connected to add multiple anti-crack points (attached Figure 5 ) to reduce the stress level at the ends of the membrane wall tube screen assemblies in high temperature areas.

[0021] In one embodiment, a plurality of temperature measurement points are provided in the tube panel outlet area.

[0022] Specifically, sufficient temperature measurement points are arranged in the tube panel outlet area, and operation adjustments are guided by the real-time temperature feedback system to improve heat load deviation and reduce the overall stress of the tube panel.

[0023] In one embodiment, the low-temperature region membrane wall tube panel and the high-temperature region membrane wall tube panel both include a plurality of tubes arranged in parallel and fins arranged between two adjacent tubes, and the fins are integrally formed with the tubes.

[0024] Specifically, the membrane water-cooled wall refers to a water-cooled wall composed of airtight tube panels welded together by flat steel and pipes. The membrane water-cooled wall can ensure that the furnace has good tightness, and for negative pressure boilers, it can significantly reduce the furnace air leakage coefficient and improve the combustion conditions in the furnace. It can increase the effective radiation heating area, thereby saving steel consumption.

[0025] In one embodiment, the material of the membrane wall tube panel assembly in the low temperature area is 12Cr1 MoVG material.

[0026] In one embodiment, the material of the high temperature area membrane wall tube panel assembly is T91 material.

[0027] Specifically, in all areas involving on-site welding, embedded parts are set up in advance to avoid on-site heat treatment.

[0028] The beneficial effects of the present invention are as follows:

[0029] 1. The present invention proposes a water-cooled wall arrangement to reduce the heat treatment problem of high-grade materials during on-site installation. At the same time, it effectively reduces the overall stress level of the tube screen and avoids the occurrence of tube screen cracking. It not only meets the needs of improving boiler parameters and efficiency, but also adapts to the current operating mode of thermal power units.

[0030] 2. Due to performance limitations, low-grade materials cannot meet the safety requirements of 630℃ ultra-high parameter boiler water-cooled walls. This type of water-cooled wall can improve the membrane wall material while ensuring safety. The water-cooled wall material proposed in the present invention is flexible in selection, and can be combined according to different parameters. With the heat-free treatment and anti-cracking structure, it can meet the needs of boilers with higher parameters such as 650℃ and 700℃.

[0031] 3. Arrange sufficient temperature measurement points in the tube panel outlet area, guide operation adjustments based on the real-time temperature feedback system, improve heat load deviation, and reduce the overall stress of the tube panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 It is a schematic diagram of the structure of the present invention;

[0034] Figure 2 It is a structural schematic diagram of the material transition zone;

[0035] Figure 3 yes Figure 1 A partial enlarged schematic diagram of the middle part;

[0036] Figure 4 It is a schematic diagram of the structure of the connection of the membrane wall tube screen assembly in the high temperature area;

[0037] Figure 5 yes Figure 1 A partial enlarged schematic diagram of the top;

[0038] Figure 6It is a structural schematic diagram of a distributed bolt structure;

[0039] Figure 7 It is the control schematic diagram of the monitoring system and regulating device;

[0040] Figure numerals: 1-membrane wall tube screen assembly in low temperature area, 2-membrane wall tube screen assembly in high temperature area, 3-material transition zone, 4-screen assembly joints on construction site, 5-anti-crack, 6-distributed bolt structure, 7-collector box, 8-monitoring system, 9-adjustment device. DETAILED DESCRIPTION

[0041] In order to make the technical problems, technical solutions and technical effects of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In addition, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0044] In the description of the embodiments of the present invention, it should be noted that the terms "inside", "outside", "upper", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0045] Example 1

[0046] like Figures 1 to 6As shown, this embodiment provides a water-cooled wall for an ultra-high parameter boiler, comprising a low-temperature region membrane wall tube panel assembly 1, a high-temperature region membrane wall tube panel assembly 2, and a material transition zone 3 between the low-temperature region membrane wall tube panel assembly 1 and the high-temperature region membrane wall tube panel assembly 2, the top of the high-temperature region membrane wall tube panel assembly 2 is a tube panel outlet area, a monitoring system 8 is provided in the tube panel outlet area, the bottom of the low-temperature region membrane wall tube panel assembly 1 is a tube panel inlet area, a regulating device 9 is provided in the tube panel inlet area, and the material grade of the low-temperature region membrane wall tube panel assembly 1 is lower than that of the high-temperature region membrane wall tube panel assembly 2;

[0047] The low-temperature region membrane-wall tube-panel assembly 1 includes a plurality of low-temperature region membrane-wall tube-panels arranged in parallel; the high-temperature region membrane-wall tube-panel assembly 2 includes a plurality of high-temperature region membrane-wall tube-panels arranged in parallel.

[0048] Specifically, the water-cooled wall of this scheme is a membrane wall tube screen. The membrane wall tube screen in the low temperature area is compared with the membrane wall tube screen in the high temperature area. The membrane wall tube screen in the high temperature area uses higher grade materials, and there is a material transition between the membrane wall tube screen in the high temperature area and the membrane wall tube screen in the low temperature area. The number of material types and the number of screens in the scheme are determined according to the furnace type and actual parameters.

[0049] Due to performance limitations, low-grade materials cannot meet the safety requirements of 630℃ ultra-high parameter boiler water-cooled walls. This type of water-cooled wall can improve the membrane wall material while ensuring safety. The water-cooled wall material proposed in the present invention is flexible in selection, and can be combined according to different parameters. With the heat-free treatment and anti-cracking structure, it can meet the needs of boilers with higher parameters such as 650℃ and 700℃.

[0050] Example 2

[0051] like Figures 1 to 7 As shown, this embodiment provides a water-cooled wall for an ultra-high parameter boiler, comprising a low-temperature region membrane wall tube panel assembly 1, a high-temperature region membrane wall tube panel assembly 2, a material transition zone 3 between the low-temperature region membrane wall tube panel assembly 1 and the high-temperature region membrane wall tube panel assembly 2, the top of the high-temperature region membrane wall tube panel assembly 2 is a tube panel outlet area 8, and the material grade of the low-temperature region membrane wall tube panel assembly 1 is lower than that of the high-temperature region membrane wall tube panel assembly 2;

[0052] The low-temperature region membrane-wall tube-panel assembly 1 includes a plurality of low-temperature region membrane-wall tube-panels arranged in parallel; the high-temperature region membrane-wall tube-panel assembly 2 includes a plurality of high-temperature region membrane-wall tube-panels arranged in parallel.

[0053] The material transition zone 3 adopts a staggered material interface.

[0054] Specifically, the material transition zone 3 adopts a staggered material interface (attached Figure 2) to make the regional material stress uniform; at the same time, a low stress structure is used for transition (attached Figure 3 ) to reduce the thermal stress caused by the expansion difference at the interface of dissimilar steels.

[0055] The membrane wall tube screens of two adjacent low-temperature areas are assembled by welding.

[0056] Specifically, the low temperature region membrane wall tube panel assembly 1 is welded and assembled in a conventional manner without the need for heat treatment.

[0057] Example 3

[0058] This embodiment is further optimized on the basis of embodiment 2, specifically:

[0059] There is a construction site panel assembly joint 4 between two adjacent high temperature area membrane wall tube panels, the two adjacent high temperature area membrane wall tube panels are connected by a composite flexible structure, and the fin flat steel between the two adjacent high temperature area membrane wall tube panels is not welded.

[0060] Specifically, the joints 4 of the membrane wall tube panels in each high temperature area are connected by a composite flexible structure (see Appendix Figure 4 ), the fin flat steel between the two screens is not welded.

[0061] Example 4

[0062] This embodiment is further optimized on the basis of embodiment 3, specifically:

[0063] A plurality of distributed tie bolt structures 6 are arranged at equal intervals from top to bottom between two adjacent high-temperature zone membrane wall tube panels.

[0064] Specifically, multiple distributed tie bolt structures 6 are used for local reinforcement to increase the integrity of the water-cooled wall (see Appendix Figure 6 ).

[0065] Example 5

[0066] This embodiment is further optimized on the basis of embodiment 4, specifically:

[0067] A header 7 is provided on the top of the high temperature area membrane wall tube panel assembly 2 and is connected to the high temperature area membrane wall tube panel assembly 2. A plurality of anti-crack 5 for reducing end stress are provided at the joint between the top of the high temperature area membrane wall tube panel and the header 7.

[0068] Specifically, in order to improve boiler efficiency, the drum boiler gradually develops into a tubular boiler to increase the heat transfer area. The boiler water flows from the drum through the downcomer into the box below, and is distributed to each tube bundle by the box. The water in these tube bundles continuously absorbs heat energy, gathers in the box above, and then flows back into the drum. The upper and lower boxes are called headers 7 or headers.

[0069] At the joint between the membrane wall tube panel assembly 2 and the header 7 in the high temperature area, multiple anti-crack 5 are added (attached Figure 5 ) to reduce the stress level at the end of the membrane wall tube panel assembly 2 in the high temperature area.

[0070] Example 6

[0071] This embodiment is further optimized on the basis of embodiment 4, specifically:

[0072] The monitoring system 8 is provided with a plurality of temperature measuring points. The monitoring system 8 and the regulating device 9 constitute a temperature monitoring system of the water-cooled wall, which can adjust the temperature distribution of the water-cooled wall in real time and reduce the temperature difference of the membrane wall.

[0073] Specifically, sufficient temperature measurement points are arranged in the outlet area of ​​the tube panel, and the operation adjustment is guided by the real-time temperature feedback system. Adjustments are made manually or automatically according to the preset logic through the adjustment device to improve the heat load deviation and reduce the overall stress of the tube panel. See the attached Figure 7 .

[0074] The low-temperature region membrane wall tube panel and the high-temperature region membrane wall tube panel both include a plurality of tubes arranged in parallel and fins arranged between two adjacent tubes, and the fins are integrally formed with the tubes.

[0075] Specifically, the membrane water-cooled wall refers to a water-cooled wall composed of airtight tube panels welded together by flat steel and pipes. The membrane water-cooled wall can ensure that the furnace has good tightness, and for negative pressure boilers, it can significantly reduce the furnace air leakage coefficient and improve the combustion conditions in the furnace. It can increase the effective radiation heating area, thereby saving steel consumption.

[0076] The material of the membrane wall tube panel assembly 1 in the low temperature area is 12Cr1 MoVG material.

[0077] The material of the membrane wall tube panel assembly 2 in the high temperature area is T91 material.

[0078] In addition, embedded parts are set in advance in all areas involving on-site welding to avoid on-site heat treatment.

Claims

1. A water-cooled wall for an ultra-high parameter boiler, characterized in that: The invention comprises a low-temperature region membrane-wall tube-panel assembly (1), a high-temperature region membrane-wall tube-panel assembly (2), and a material transition zone (3) located between the low-temperature region membrane-wall tube-panel assembly (1) and the high-temperature region membrane-wall tube-panel assembly (2); the top of the high-temperature region membrane-wall tube-panel assembly (2) is a tube-panel outlet area, and a monitoring system (8) is provided in the tube-panel outlet area; the bottom of the low-temperature region membrane-wall tube-panel assembly (1) is a tube-panel inlet area, and a regulating device (9) is provided in the tube-panel inlet area; the material grade of the low-temperature region membrane-wall tube-panel assembly (1) is lower than that of the high-temperature region membrane-wall tube-panel assembly (2); The low-temperature region membrane-wall tube-screen assembly (1) comprises a plurality of low-temperature region membrane-wall tube-screens arranged in parallel; the high-temperature region membrane-wall tube-screen assembly (2) comprises a plurality of high-temperature region membrane-wall tube-screens arranged in parallel.

2. The water-cooled wall for an ultra-high parameter boiler according to claim 1, characterized in that: The material transition zone (3) adopts a staggered material interface.

3. The water-cooled wall for an ultra-high parameter boiler according to claim 1, characterized in that: Two adjacent low-temperature zone membrane wall tube panels are assembled by welding.

4. The water-cooled wall for an ultra-high parameter boiler according to claim 1, characterized in that: There is a construction site panel assembly joint (4) between two adjacent high temperature area membrane wall tube panels, the two adjacent high temperature area membrane wall tube panels are connected by a composite flexible structure, and the fin flat steel between the two adjacent high temperature area membrane wall tube panels is not welded.

5. The water-cooled wall for an ultra-high parameter boiler according to claim 4, characterized in that: A plurality of distributed tie bolt structures (6) are arranged at equal intervals from top to bottom between two adjacent high-temperature region membrane wall tube panels.

6. The water-cooled wall for an ultra-high parameter boiler according to claim 1, characterized in that: A header (7) connected to the high-temperature region membrane wall tube panel assembly (2) is provided at the top of the high-temperature region membrane wall tube panel assembly (2), and a plurality of anti-crack (5) for reducing end stress is provided at the joint between the top of the high-temperature region membrane wall tube panel and the header (7).

7. The water-cooled wall for an ultra-high parameter boiler according to claim 1, characterized in that: The monitoring system (8) is provided with a plurality of temperature measurement points. The monitoring system (8) and the regulating device (9) constitute a water-cooled wall temperature monitoring system, which can regulate the water-cooled wall temperature distribution in real time and reduce the membrane wall temperature difference.

8. The water-cooled wall for an ultra-high parameter boiler according to claim 1, characterized in that: The low-temperature region membrane-wall tube panel and the high-temperature region membrane-wall tube panel both include a plurality of tubes arranged in parallel and fins arranged between two adjacent tubes, and the fins are integrally formed with the tubes.

9. The water-cooled wall for an ultra-high parameter boiler according to claim 1, characterized in that: The material of the low temperature area membrane wall tube panel assembly (1) is 12Cr1 MoVG material.

10. The water-cooled wall for an ultra-high parameter boiler according to claim 1, characterized in that: The material of the high temperature area membrane wall tube panel assembly (2) is T91 material.

Images