Boiler water wall system with anti-cracking and heat shielding dual response characteristics and thermal power generating unit

Abstract

The application discloses a boiler water cooling wall system and a thermal power generating unit with anti-cracking and heat-shielding double-response characteristics, which comprises an outer layer water cooling wall with an outer layer tube bundle and fins and an inner layer water cooling wall with an inner layer tube bundle. The outer layer tube bundle is arranged side by side along the circumference of the boiler water cooling wall, and fins are arranged between at least two adjacent outer layer tube bundles. The inner layer water cooling wall is arranged on the inner side of the space surrounded by the outer layer water cooling wall, the inner layer tube bundle and the fins are oppositely arranged along the thickness direction of the boiler water cooling wall, and the flow area of the inner layer tube bundle is smaller than that of the outer layer tube bundle. The inner layer water cooling wall shields the radiation heat of the furnace, protects the fins of the outer layer water cooling wall and reduces the temperature of the fins. The diameter of the inner layer tube bundle of the inner layer water cooling wall is smaller than that of the outer layer tube bundle, so that the inner layer water cooling wall adopts a high mass flow rate and the outer layer water cooling wall adopts a low mass flow rate, sufficient cooling capacity is provided for the pipeline, the heat absorption deviation between the pipelines of the water cooling wall is adjusted, and the safety of the boiler water cooling wall is protected.

Description

Technical Field

[0001] This invention relates to the technical field of power generation technology, and in particular to a boiler water-cooled wall system and thermal power unit with anti-tear-splitting heat-shielding dual-response characteristics. Background Technology

[0002] Currently, the proportion of new energy power generation continues to increase, and thermal power units need to undertake the task of frequent and deep peak shaving. This makes rapid load change of thermal power units the norm, causing the temperature inside the boiler furnace to rise and fall sharply, which significantly aggravates the thermal shock borne by the boiler water-cooled wall.

[0003] When the furnace temperature of a boiler rises or falls rapidly, the flow rate of the working medium in different pipes of the boiler water-cooled wall changes drastically. This causes significant thermal stress on the pipe walls and fins of the boiler water-cooled wall, frequently leading to cracking of the boiler water-cooled wall. Summary of the Invention

[0004] In view of this, the present invention provides a boiler water-cooled wall system with anti-tear-and heat-shielding dual-response characteristics to alleviate the problem of boiler water-cooled wall tearing.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A boiler water-cooled wall system with anti-tear-and heat-shielding dual-response characteristics includes: an outer water-cooled wall, the outer water-cooled wall including an outer tube bundle and fins, the outer tube bundle being a channel extending along the height direction of the boiler water-cooled wall, the outer tube bundle being arranged side by side along the circumference of the boiler water-cooled wall, and the fins being disposed between at least two adjacent outer tube bundles.

[0007] The inner water-cooled wall is disposed inside the space enclosed by the outer water-cooled wall, and the inner water-cooled wall includes an inner tube bundle, which is a channel extending along the height direction, and the inner tube bundle is arranged circumferentially along the boiler water-cooled wall. The inner tube bundle and the fins are arranged opposite to each other along the thickness direction of the boiler water-cooled wall.

[0008] The flow area of ​​the inner tube bundle is smaller than that of the outer tube bundle.

[0009] Preferably, in the above-mentioned anti-tear-resistant heat-shielding dual-response boiler water-cooled wall system, the projection of the inner tube bundle along the thickness direction onto the opposing fins can at least cover a portion of the fins.

[0010] Preferably, in the above-mentioned anti-tear-stripping heat-shielding dual-response boiler water-cooled wall system, the first end of the inner tube bundle along the height direction is connected to the inner water-cooled wall inlet header, and the second end of the inner tube bundle along the height direction is connected to the inner water-cooled wall outlet header.

[0011] Along the height direction of the boiler water-cooled wall, the inlet header of the inner water-cooled wall is arranged lower than the outlet header of the inner water-cooled wall.

[0012] Preferably, in the above-mentioned anti-tear-stripping heat-shielding dual-response boiler water-cooled wall system, the first end of the inner tube bundle passes through the outer side of the outer water-cooled wall and is connected to the inlet header of the inner water-cooled wall.

[0013] The outer water-cooled wall has a bent structure at the position opposite to the first end of the inner tube bundle, and it bends towards the outside of the outer water-cooled wall.

[0014] Preferably, in the above-mentioned anti-tear-stripping heat-shielding dual-response boiler water-cooled wall system, a throttling short pipe is provided between the inner tube bundle and the inner water-cooled wall inlet header;

[0015] The throttling short tubes correspond one-to-one with the inner tube bundles.

[0016] Preferably, in the above-mentioned anti-tear-stripping heat-shielding dual-response boiler water-cooled wall system, the first end of the outer tube bundle along the height direction is connected to the inlet header of the outer water-cooled wall, and the second end of the outer tube bundle along the height direction is connected to the outlet header of the outer water-cooled wall.

[0017] Along the height direction of the boiler water-cooled wall, the inlet header of the outer water-cooled wall is arranged lower than the outlet header of the outer water-cooled wall.

[0018] Preferably, the above-mentioned anti-tear-stripping heat-shielding dual-response boiler water-cooled wall system further includes: a water supply pipeline, wherein the inner water-cooled wall inlet header is connected to the water supply pipeline through a first water-cooled wall inlet connecting pipeline;

[0019] The external water-cooled wall inlet header is connected to the water supply pipeline through the second water-cooled wall inlet connecting pipe;

[0020] The first water-cooled wall inlet connection pipe and the second water-cooled wall inlet connection pipe are connected.

[0021] Preferably, in the above-mentioned anti-tear-stripping heat-shielding dual-response boiler water-cooled wall system, at least one of a regulating valve and a feedwater flow meter is provided on the first water-cooled wall inlet connecting pipe and / or the second water-cooled wall inlet connecting pipe.

[0022] The regulating valve is used to regulate the flow rate in the pipeline, and the water flow meter is used to detect the flow rate in the pipeline.

[0023] Preferably, in the above-mentioned anti-tear-resistant heat-shielding dual-response boiler water-cooled wall system, the inner water-cooled wall outlet header and the outer water-cooled wall outlet header are connected to the gas-liquid separator.

[0024] A thermal power unit includes a boiler water-cooled wall, wherein the boiler water-cooled wall is a boiler water-cooled wall system with anti-tear-splitting heat-shielding dual-response characteristics as described in any of the above claims.

[0025] This invention discloses a boiler water-cooled wall system with anti-tear-prone heat-shielding dual-response characteristics. It adopts a heat-shielding dual-response system design with an inner water-cooled wall and an outer water-cooled wall. The inner water-cooled wall effectively protects the fins of the outer water-cooled wall and reduces their temperature by shielding the furnace radiant heat. Furthermore, the diameter of the inner tube bundle of the inner water-cooled wall is smaller than that of the outer tube bundle, allowing the inner water-cooled wall to use a high-mass flow rate while the outer water-cooled wall uses a low-mass flow rate. This provides sufficient cooling capacity for the pipes while better adapting to the heat absorption deviations between the pipes of the water-cooled wall during rapid load changes in thermal power units, thereby maximizing the safety of the boiler water-cooled wall. This system can further improve the load change rate of thermal power units based on existing technology. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 Numerical simulation diagram of temperature distribution of boiler water-cooled wall tubes under different flow fluctuations in the existing technology;

[0028] Figure 2 This is a front view of the anti-tear-stripping heat-shielding dual-response boiler water-cooled wall system disclosed in an embodiment of the present invention;

[0029] Figure 3 for Figure 2 A partial sectional view of AA;

[0030] Figure 4 This is a diagram showing the dimensional relationship between the inner and outer water-cooled walls as disclosed in an embodiment of the present invention.

[0031] Figure 5 for Figure 2 A partial left view at point B in the middle.

[0032] in,

[0033] 1-Outer water-cooled wall, 11-Outer tube bundle, 12-Fin, 2-Inner water-cooled wall, 21-Inner tube bundle, 31-Water supply pipeline, 32-First water-cooled wall inlet connection pipeline, 33-Second water-cooled wall inlet connection pipeline, 34-Water supply flow meter, 35-Regulating valve, 36-Water-cooled wall outlet connection pipeline, 41-Inner water-cooled wall inlet header, 42-Inner water-cooled wall outlet header, 43-Throttling short pipe, 51-Outer water-cooled wall inlet header, 52-Outer water-cooled wall outlet header, 6-Steam-water separator. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0036] Currently, the proportion of new energy power generation continues to increase, and thermal power units need to undertake the task of frequent and deep peak shaving, making rapid load change of thermal power units the norm. This causes the temperature inside the boiler furnace to rise and fall sharply, which significantly aggravates the thermal shock experienced by the boiler water-cooled walls.

[0037] Current boiler water-cooled walls consist of pipes and fins connecting the pipes. The working fluid flows through the pipes, and the fins dissipate heat from the working fluid within the pipes. When the boiler furnace temperature rises and falls rapidly, the flow rate of the working fluid in different pipes of the boiler water-cooled wall changes drastically, resulting in significant thermal stress on both the pipe walls and fins. Currently, traditional membrane water-cooled wall designs have poor adaptability to rapid dynamic conditions, frequently leading to water-cooled wall cracking during actual operation. This cracking is most common in the fins, but some cases involve pipes bursting due to overheating.

[0038] like Figure 1 As shown, the temperature distribution of the pipes in the water-cooled wall of a 660MW boiler was calculated through numerical simulation, and the results were obtained. Figure 1 The attached diagram is shown. From Figure 1 It can be seen that under different flow rate fluctuations, the highest temperature of the boiler water-cooled wall tubes occurs in the inter-tube fin section, that is, the fin tip temperature is the highest. Under flow rate fluctuations, the fin tip temperature fluctuation can reach more than 80℃, which also proves that the water-cooled wall tube fins are the weakest link in the safety of the water-cooled wall.

[0039] To reduce the problem of cracking in boiler water-cooled walls, this application discloses a crack-resistant, heat-shielding, dual-response boiler water-cooled wall system. It adopts a dual-response system design with an inner water-cooled wall and an outer water-cooled wall. The inner water-cooled wall effectively protects the fins of the outer water-cooled wall by shielding the radiant heat from the furnace, reducing the fin temperature. Furthermore, the inner water-cooled wall uses a high-mass flow rate while the outer water-cooled wall uses a low-mass flow rate, providing sufficient cooling capacity for the pipes while better adapting to heat absorption deviations between the pipes in the water-cooled wall during rapid load changes in thermal power units. This maximizes the safety of the boiler water-cooled wall and can further improve the load change rate of thermal power units based on existing technology.

[0040] The structure of the boiler water-cooled wall system with anti-tear-splitting heat-shielding dual-response characteristics according to an embodiment of this application will be described below with reference to the accompanying drawings.

[0041] like Figure 2 and Figure 3 As shown, the anti-tear-resistant, heat-shielding, dual-response boiler water-cooled wall system includes an outer water-cooled wall 1 and an inner water-cooled wall 2. The outer water-cooled wall 1 includes an outer tube bundle 11 and fins 12. The inner water-cooled wall 2 includes an inner tube bundle 21.

[0042] The outer tube bundle 11 is a channel extending along the height direction of the boiler water-cooled wall. The outer tube bundle 11 is arranged side-by-side along the circumference of the boiler water-cooled wall. It should be noted that the height direction in this text can be... Figure 2 The vertical direction, the circumferential direction is Figure 3 Zhou Xiang in the middle.

[0043] The outer tube bundle 11 can consist of multiple tubes connected in parallel and distributed circumferentially along the boiler water-cooled wall. The number of outer tube bundles 11 can be set according to different needs. Figure 3 The example only illustrates one number of outer tube bundles 11, but does not constitute a limitation on the number of outer tube bundles 11.

[0044] At least two adjacent outer tube bundles 11 are provided with fins 12. Optionally, the fins 12 connect adjacent outer tube bundles 11 and surround an outer water-cooled wall 1. In some embodiments, the outer water-cooled wall 1 may be a rectangular structure or a cylindrical structure. The outer tube bundles 11 may be circular tube channels or rectangular tube channels.

[0045] The inner water-cooled wall 2 is located inside the space enclosed by the outer water-cooled wall 1, thus making the boiler wall double-layered. The inner tube bundle 21 of the inner water-cooled wall 2 is a channel that runs through the height of the boiler water-cooled wall, and the inner tube bundle 21 is arranged side by side along the circumference of the boiler water-cooled wall. In this way, the inner tube bundle 21 forms an inner water-cooled wall 2 with the same shape as the outer water-cooled wall 1. For example, if the outer water-cooled wall 1 is a rectangular structure, the inner water-cooled wall 2 can also be a rectangular structure. Of course, the shapes of the outer water-cooled wall 1 and the inner water-cooled wall 2 can also be different. For example, the outer water-cooled wall 1 is a rectangular structure, and the inner water-cooled wall 2 is a cylindrical structure.

[0046] In some embodiments, the inner tube bundle 21 and the fins 12 are arranged opposite each other along the thickness direction. This can be understood as follows: when both the outer water-cooled wall 1 and the inner water-cooled wall 2 are rectangular structures, the inner tube bundle 21 is arranged along the length and width directions of the boiler, and the inner tube bundle 21 is arranged opposite each other along the thickness direction of the boiler. That is, the inner tube bundle 21 arranged side by side along the length direction and the fins 12 arranged along the length direction are arranged opposite each other along the thickness direction; the inner tube bundle 21 arranged side by side along the width direction and the fins 12 arranged along the width direction are arranged opposite each other along the thickness direction.

[0047] It should be noted that the boiler water-cooled wall of this application includes an outer water-cooled wall 1 and an inner water-cooled wall 2, so that the boiler water-cooled wall forms a double-layer structure. The inner tube bundle 21 of the inner water-cooled wall 2 and the fins 12 of the outer water-cooled wall have a corresponding relationship. That is, the fins 12 of the outer water-cooled wall 1 are "shielded" by the inner tube bundle 21 of the inner water-cooled wall 2, thereby reducing the radiative heat release of the flue gas in the furnace to the fins 12 of the outer water-cooled wall 1, that is, realizing the "heat shielding" design.

[0048] In this embodiment, there is a gap between the inner tube bundle 21 and the fin 12 along the thickness direction. The size of the gap is not limited, and there may also be gaps between the inner tube bundles 21, that is, adjacent inner tube bundles 21 do not contact each other, so as to reduce heat transfer between adjacent inner tube bundles 21. Optionally, the inner tube bundle 21 can be suspended in the boiler.

[0049] In some embodiments, the inner tube bundle 21 is arranged in a one-to-one correspondence with the fin 12. Optionally, the projection of the inner tube bundle 21 along the thickness direction onto the opposite fin 12 can at least cover a portion of the fin 12, thereby improving the shielding effect of the inner tube bundle 21 on the fin 12.

[0050] It should be understood that: when the boiler has a rectangular structure, if the fin 12 is the fin 12 on the side wall along the length direction of the boiler, then the dimension of the fin 12 along the length direction is greater than the dimension of the inner tube bundle 21 opposite to the fin 12 along the thickness direction along the length direction; if the fin 12 is the fin 12 on the side wall along the width direction of the boiler, then the dimension of the fin 12 along the width direction is greater than the dimension of the inner tube bundle 21 opposite to the fin 12 along the thickness direction along the width direction.

[0051] In some cases, the projection of the inner tube bundle 21 along the thickness direction onto the opposite fin 12 can at least cover a portion of the fin 12, provided that the size of the inner tube bundle 21 is larger than the size of the fin 12.

[0052] like Figure 4 As shown, in this embodiment, the dimension L1 of the inner tube bundle 21 along the first direction is greater than the dimension L2 of the fin 12 opposite to it along the thickness direction along the second direction. It should be understood that the first direction can be the length direction or the width direction, and in the scenario where the boiler water-cooled wall is a cylindrical structure, the first direction can also be radial.

[0053] In this embodiment, the size of the inner tube bundle 21 is larger than the size of the fin 12, so that the projection of the inner tube bundle 21 along the thickness direction on the opposite fin 12 can at least cover a part of the fin 12, thereby improving the shielding effect of the inner tube bundle 21 on the fin 12.

[0054] In some embodiments, the flow area of ​​the inner tube bundle 21 is smaller than the flow area of ​​the outer tube bundle 11. It should be understood that there are multiple inner tube bundles 21 and multiple outer tube bundles 11 in this document. The flow area of ​​all inner tube bundles 21 can be the same, and the flow area of ​​all outer tube bundles 11 can also be the same. The flow area of ​​the inner tube bundle 21 is smaller than the flow area of ​​the outer tube bundle 11.

[0055] In some embodiments, the flow area of ​​the inner tube bundle 21 is smaller than that of the outer tube bundle 11, which can be achieved by setting the diameter of the inner tube bundle 21 to be smaller than that of the outer tube bundle 11.

[0056] The outer tube bundle 11 of the outer water-cooled wall 1 of the boiler uses a large tube diameter, which results in a low working fluid velocity within the outer tube bundle 11, i.e., a low mass flow velocity (typically below 1200 kg / (m³)). 2The low mass flow rate design of the water-cooled wall provides a positive response characteristic similar to that of a steam drum boiler. The principle is that when the working fluid within the water-cooled wall has a low mass flow rate, the proportion of frictional resistance in the total resistance becomes very small, while the proportion of gravity pressure drop is relatively large. This allows the flow distribution of the working fluid within the water-cooled wall pipes to automatically adapt to the heat load distribution; that is, the flow rate of the working fluid in pipes with high heat load increases accordingly, while the flow rate in pipes with low heat load decreases accordingly. Therefore, with a constant total flow rate, the phenomenon of excessively high outlet temperatures caused by localized heat absorption in the water-cooled wall pipes is effectively suppressed. This significantly reduces the thermal deviation of the water-cooled wall, resulting in a more uniform outlet temperature for each pipe in the water-cooled wall, effectively preventing fin cracking caused by excessive temperature differences and localized overheating between pipes, thus ensuring the safe operation of the boiler.

[0057] Choosing a smaller tube diameter for the inner water-cooled wall 2 results in a higher working fluid velocity within the inner tube bundle 21, meaning the inner tube bundle 21 is designed for high-quality flow. This high-quality flow allows the inner tube bundle 21 to achieve excellent cooling performance, which is beneficial for protecting the water-cooled wall tubes.

[0058] In this embodiment, the inner water-cooled wall 2 and the outer water-cooled wall 1 are designed with different mass flow rates, so that the water-cooled wall exhibits "dual-response" flow characteristics. In addition, the inner water-cooled wall 2 and the outer water-cooled wall 1 are designed with different mass flow rates, so that the total mass flow rate of the boiler water-cooled wall does not exceed the general design value, and will not cause the problem of excessive resistance of the boiler water-cooled wall system leading to increased power consumption of the feedwater pump.

[0059] See also Figure 2 As shown, the boiler water-cooled wall system with anti-tear-and-shield heat-shielding dual-response characteristics in this embodiment further includes: an inner water-cooled wall inlet header 41, an inner water-cooled wall outlet header 42, an outer water-cooled wall inlet header 51, and an outer water-cooled wall outlet header 52.

[0060] The inner tube bundle 21 has its first end along the height direction connected to the inner water-cooled wall inlet header 41, and its second end along the height direction connected to the inner water-cooled wall outlet header 42. Optionally, the connection between the inner tube bundle 21 and the inner water-cooled wall inlet header 41, and between the inner tube bundle 21 and the inner water-cooled wall outlet header 42, can be achieved through an adapter or by direct connection.

[0061] In some embodiments, along the height direction of the boiler water-cooled wall, the inner water-cooled wall inlet header 41 is arranged lower than the inner water-cooled wall outlet header 42. This allows the cooling working fluid to enter the inner tube bundle 21 from below the boiler water-cooled wall, exchange heat with the boiler furnace, become gaseous, and exit from above the boiler water-cooled wall. This method increases the heat exchange path of the working fluid and reduces its dynamics, achieving circulation solely through the fluid's own flow, thus reducing costs.

[0062] Combination Figure 5 As shown, the first end of the inner tube bundle 21 passes through the outer side of the outer water-cooled wall 1 and is connected to the inlet header 41 of the inner water-cooled wall. The position in the outer water-cooled wall 1 opposite to the first end of the inner tube bundle 21 is a bent structure and bends towards the outer side of the outer water-cooled wall 1.

[0063] In this way, the inner tube bundle 21 can be connected to the inner water-cooled wall inlet header 41 on the outer side of the outer water-cooled wall 1.

[0064] Figure 2 As shown, a throttling pipe 43 is provided between the inner tube bundle 21 and the inlet header 41 of the inner water-cooled wall. Optionally, the throttling pipe 43 is provided in a one-to-one correspondence with the inner tube bundle 21.

[0065] A throttling short pipe 43 is installed at the inlet of the inner tube bundle 21 to adjust the flow rate of each inner tube bundle 21 and reduce the thermal deviation between each inner tube bundle 21.

[0066] It should be noted that the throttling size of the throttling short tube 43 in this article can be set according to the length and diameter of the throttling short tube 43, and is determined during the processing of the throttling short tube 43.

[0067] In this embodiment, the first end of the outer tube bundle 11 along the height direction is connected to the outer water-cooled wall inlet header 51, and the second end of the outer tube bundle 11 along the height direction is connected to the outer water-cooled wall outlet header 52. Optionally, the connection between the outer tube bundle 11 and the outer water-cooled wall inlet header 51, and between the outer tube bundle 11 and the outer water-cooled wall outlet header 52, can be achieved by using an adapter or by direct connection.

[0068] In some embodiments, along the height direction of the boiler water-cooled wall, the outer water-cooled wall inlet header 51 is arranged lower than the outer water-cooled wall outlet header 52. This allows the cooling working fluid to enter the outer tube bundle 11 from below the boiler water-cooled wall, exchange heat with the boiler furnace, become gaseous, and exit from above the boiler water-cooled wall. This method increases the heat exchange path of the working fluid and reduces its dynamics, achieving circulation solely through the fluid's own flow, thus reducing costs.

[0069] Figure 2 In this embodiment, the boiler water-cooled wall system with anti-tear-and-shield heat-shielding dual-response characteristics further includes: a water supply pipe 31, a first water-cooled wall inlet connection pipe 32, a second water-cooled wall inlet connection pipe 33, a water supply flow meter 34, a regulating valve 35, and a water-cooled wall outlet connection pipe 36.

[0070] The inner water-cooled wall inlet header 41 is connected to the water supply pipeline 31 through the first water-cooled wall inlet connecting pipe 32; the outer water-cooled wall inlet header 51 is connected to the water supply pipeline 31 through the second water-cooled wall inlet connecting pipe 33.

[0071] The inner water-cooled wall inlet header 41 and the outer water-cooled wall inlet header 51 are respectively connected to the water supply pipeline 31 to provide working fluid to the inner tube bundle 21 and the outer tube bundle 11. It should be noted that the working fluid in this article can be water.

[0072] In some embodiments, the first water-cooled wall inlet connection pipe 32 and the second water-cooled wall inlet connection pipe 33 are connected, so that the outlet of the water supply pipe 31 has two parallel pipes.

[0073] Optionally, the first water-cooled wall inlet connecting pipe 32 and the second water-cooled wall inlet connecting pipe 33 can be a single pipe, which simplifies the structure and reduces costs.

[0074] At least one of a regulating valve 35 and a water flow meter 34 is provided on the first water-cooled wall inlet connecting pipe 32 and / or the second water-cooled wall inlet connecting pipe 33.

[0075] The regulating valve 35 is used to regulate the flow rate of the pipeline, and the water flow meter 34 is used to detect the flow rate of the pipeline.

[0076] By setting the regulating valve 35 and the water flow meter 34, the water flow rate distributed to the outer water-cooled wall inlet header 51 and the inner water-cooled wall inlet header 41 can be adjusted, thereby ensuring that the mass flow rate of the working fluid in the outer water-cooled wall 1 and the inner water-cooled wall 2 is within the design value range.

[0077] One end of the outer tube bundle 11 of the outer water-cooled wall 1 along the height direction is connected to the outer water-cooled wall outlet header 52, and one end of the inner tube bundle 21 of the inner water-cooled wall 2 along the height direction is connected to the inner water-cooled wall outlet header 42. Both the inner water-cooled wall outlet header 42 and the outer water-cooled wall outlet header 52 are connected to the water-cooled wall outlet connecting pipe 36. The water-cooled wall outlet connecting pipe 36 consists of multiple connecting pipes, which eventually converge and connect to the steam-water separator 6.

[0078] During the boiler operation, the boiler feedwater (working fluid) first enters the inner water-cooled wall inlet header 41 through the feedwater pipeline 31, then through the first water-cooled wall inlet connecting pipeline 32, and then through the second water-cooled wall inlet connecting pipeline 33 into the outer water-cooled wall inlet header 51. The feedwater flow rate distributed to the outer water-cooled wall inlet header 51 and the inner water-cooled wall inlet header 41 can be adjusted by the regulating valve 35, thereby ensuring that the mass flow rate of the working fluid in the outer water-cooled wall 1 and the inner water-cooled wall 2 is within the design value range.

[0079] The working fluid in the outer water-cooled wall 1 and the inner water-cooled wall 2 is heated by the high-temperature flue gas in the furnace and rises vertically. It enters the outer water-cooled wall outlet header 52 and the inner water-cooled wall outlet header 42 respectively, and is finally combined in the steam-water separator 6 through multiple water-cooled wall outlet connecting pipes 36. After steam-water separation, it goes to the boiler superheater system for further heating.

[0080] During the rapid load change of thermal power units, the flue gas temperature in the furnace rises and falls sharply, and the drastic change in the flow rate of the working medium in the pipes of the boiler water-cooled wall causes large heat absorption and flow deviations in the boiler water-cooled wall. Traditionally designed boiler water-cooled walls often suffer from problems such as cracking of fins due to excessively high temperature or tube rupture due to overheating of pipes.

[0081] The anti-tear-prone, heat-shielding, dual-response boiler water-cooled wall system of this embodiment employs a double-layer design. The high-mass flow rate design of the inner water-cooled wall 2 can adapt to high-temperature operating conditions, and the inner tube bundle 21 of the inner water-cooled wall 2 has no intermediate fins, thus eliminating the tearing problem. The low-mass flow rate design of the outer water-cooled wall 1 has a positive response characteristic that can adapt to thermal deviation issues. At the same time, the fins 12 of the outer water-cooled wall 1 are shielded by the inner tube bundle 21 of the inner water-cooled wall 2, greatly reducing the heat absorption of the fins 12, thereby effectively preventing the tearing problem of the fins 12. Therefore, the anti-tear-prone, heat-shielding, dual-response boiler water-cooled wall system of this invention is more suitable for boilers operating under rapid load changes.

[0082] Furthermore, this application also discloses a thermal power unit, including a boiler water-cooled wall, wherein the boiler water-cooled wall is the anti-tear-blocking heat-shielding dual-response boiler water-cooled wall system disclosed in the above embodiments. Therefore, the thermal power unit with the anti-tear-blocking heat-shielding dual-response boiler water-cooled wall system also has all the above-mentioned technical effects, which will not be elaborated here.

[0083] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0084] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A boiler water-cooled wall system with anti-tear-and-shield heat-shielding dual-response characteristics, characterized in that, include: The outer water-cooled wall (1) includes an outer tube bundle (11) and fins (12). The outer tube bundle (11) is a channel that runs through the height of the boiler water-cooled wall. The outer tube bundle (11) is arranged side by side along the circumference of the boiler water-cooled wall. The fins (12) are provided between at least two adjacent outer tube bundles (11). The inner water-cooled wall (2) is located inside the space enclosed by the outer water-cooled wall (1), and the inner water-cooled wall (2) includes an inner tube bundle (21). The inner tube bundle (21) is a channel that runs through the height direction, and the inner tube bundle (21) is arranged side by side along the circumference of the boiler water-cooled wall. The inner tube bundle (21) and the fins (12) are arranged opposite to each other along the thickness direction of the boiler water-cooled wall. The flow area of ​​the inner tube bundle (21) is smaller than the flow area of ​​the outer tube bundle (11).

2. The boiler water-cooled wall system with anti-tear-and-shield heat-shielding dual-response characteristics according to claim 1, characterized in that, The projection of the inner tube bundle (21) along the thickness direction onto the opposite fin (12) can at least cover a portion of the fin (12).

3. The boiler water-cooled wall system with anti-tear-and-shield heat-shielding dual-response characteristics according to claim 1, characterized in that, The inner tube bundle (21) is connected to the inner water-cooled wall inlet header (41) at its first end along the height direction, and the inner tube bundle (21) is connected to the inner water-cooled wall outlet header (42) at its second end along the height direction. Along the height direction of the boiler water-cooled wall, the inlet header (41) of the inner water-cooled wall is arranged lower than the outlet header (42) of the inner water-cooled wall.

4. The boiler water-cooled wall system with anti-tear-and-shield heat-shielding dual-response characteristics according to claim 3, characterized in that, The first end of the inner tube bundle (21) passes through the outer side of the outer water-cooled wall (1) and is connected to the inlet header (41) of the inner water-cooled wall. The outer water-cooled wall (1) is bent at the position opposite to the first end of the inner tube bundle (21), and bends toward the outside of the outer water-cooled wall (1).

5. The boiler water-cooled wall system with anti-tear-splitting heat-shielding dual-response characteristics according to claim 3 or 4, characterized in that, A throttling pipe (43) is provided between the inner tube bundle (21) and the inlet header (41) of the inner water-cooled wall. The throttling short tube (43) corresponds one-to-one with the inner tube bundle (21).

6. The boiler water-cooled wall system with anti-tear-splitting heat-shielding dual-response characteristics according to claim 3 or 4, characterized in that, The outer tube bundle (11) is connected to the inlet header (51) of the outer water-cooled wall at its first end along the height direction, and the outer tube bundle (11) is connected to the outlet header (52) of the outer water-cooled wall at its second end along the height direction. Along the height direction of the boiler water-cooled wall, the outer water-cooled wall inlet header (51) is arranged lower than the outer water-cooled wall outlet header (52).

7. The boiler water-cooled wall system with anti-tear-and-shield heat-shielding dual-response characteristics according to claim 6, characterized in that, Also includes: Water supply pipeline (31), the inner water-cooled wall inlet header (41) is connected to the water supply pipeline (31) through the first water-cooled wall inlet connecting pipeline (32); The external water-cooled wall inlet header (51) is connected to the water supply pipeline (31) through the second water-cooled wall inlet connecting pipe (33); The first water-cooled wall inlet connecting pipe (32) and the second water-cooled wall inlet connecting pipe (33) are connected.

8. The boiler water-cooled wall system with anti-tear-and-shield heat-shielding dual-response characteristics according to claim 7, characterized in that, At least one of a regulating valve (35) and a water flow meter (34) is provided on the first water-cooled wall inlet connecting pipe (32) and / or the second water-cooled wall inlet connecting pipe (33); The regulating valve (35) is used to regulate the flow rate of the pipeline, and the water flow meter (34) is used to detect the flow rate of the pipeline.

9. The boiler water-cooled wall system with anti-tear-and-shield heat-shielding dual-response characteristics according to claim 6, characterized in that, The inner water-cooled wall outlet header (42) and the outer water-cooled wall outlet header (52) are connected to the gas-liquid separator (6).

10. A thermal power unit, comprising a boiler water-cooled wall, characterized in that, The boiler water-cooled wall is a boiler water-cooled wall system with anti-tear-stripping heat-shielding dual-response characteristics as described in any one of claims 1 to 9.

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