Ammonia-doped combustion boiler system

Abstract

This invention discloses a wide-proportion ammonia-blended combustion boiler system. The system includes a boiler system and a feedwater system. A main flue economizer is located in the main flue. A first-stage bypass economizer and a second-stage bypass economizer are both located in the bypass flue. One feedwater pump is connected to a high-pressure heater assembly via a first control valve, and the other feedwater pump is connected to the high-pressure heater assembly via a second control valve and the second-stage bypass economizer. The high-pressure heater assembly is connected to the main flue economizer via a pipeline. One path of the main flue economizer is connected to the boiler's water-cooled wall via a third control valve, and the other path of the main flue economizer is connected to the boiler's water-cooled wall via a fourth control valve and the first-stage bypass economizer. According to this invention, the wide-proportion ammonia-blended combustion boiler system can effectively absorb and utilize the heat in the flue gas generated after ammonia blending, and can effectively achieve the goal of efficient heat utilization within a wide range of ammonia blending ratios.

Description

Technical Field

[0001] This invention relates to the field of coal-fired power generation technology, and in particular to a boiler system with a wide range of ammonia blending capabilities. Background Technology

[0002] Wide-proportion ammonia blending combustion technology for coal-fired boilers is an important technological path for the coal-fired power industry to achieve a clean and low-carbon transformation under the "dual carbon" goal. Traditional coal-fired boilers use pulverized coal as the sole fuel, emitting large amounts of CO2 during combustion, making it difficult to meet the rigid constraints of national carbon peaking and carbon neutrality requirements. Ammonia, as a zero-carbon fuel, has advantages such as convenient storage and transportation, high energy density, and flexible coupling with renewable energy systems such as wind and solar power, making it one of the important carriers for achieving a low-carbon energy transformation. Blending ammonia with coal in boilers provides a flexible and feasible solution for the low-carbon transformation of coal-fired power plants.

[0003] Ammonia, as a hydrogen-rich fuel, exhibits significantly different thermodynamic characteristics compared to pure coal-fired design conditions. During combustion, ammonia undergoes a complete oxidation reaction, generating a large amount of water vapor. Taking ammonia-blended combustion at a 30% ratio as an example, compared to pure coal conditions, the flue gas volume can increase by 3.3%, and the water content in the flue gas can increase by up to 123.3%, resulting in a significant increase in exhaust heat loss. To achieve deep utilization of waste heat, it is necessary to prevent condensation and corrosion on heating surfaces. Furthermore, the increase in total flue gas volume and water vapor content leads to a corresponding increase in the heat exchange capacity of convective heating surfaces, thereby disrupting the original heat exchange balance.

[0004] Currently, most coal-fired boilers using ammonia blending are limited to modifications that involve local structural optimization or fine-tuning of operating parameters, making it difficult to achieve the goal of efficient heat utilization within a wide range of ammonia blending ratios. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one object of the present invention is to provide a wide-proportion ammonia-blended combustion boiler system, which can effectively absorb and utilize the heat in the flue gas generated after ammonia blending, and can effectively achieve the goal of efficient heat utilization within a wide range of ammonia blending ratios.

[0006] According to an embodiment of the present invention, a wide-proportion ammonia-blending combustion boiler system includes: a boiler system having a flue, the flue including a main flue and a bypass flue, the inlet end of the bypass flue being provided with a flue gas damper adapted to rotate for distributing the flue gas flow rates of the main flue and the bypass flue; and a feedwater system including: a feedwater pump, a first-stage bypass economizer, a second-stage bypass economizer, a high-pressure heater assembly, and a main flue economizer, the main flue economizer being located in the main flue, and both the first-stage bypass economizer and the second-stage bypass economizer... Located in the bypass flue and in the direction of flue gas flow, the first-stage bypass economizer is located upstream of the second-stage bypass economizer. One path of the feedwater pump is connected to the high-pressure heater assembly through a first control valve, and the other path of the feedwater pump is connected to the high-pressure heater assembly through a second control valve and the second-stage bypass economizer. The high-pressure heater assembly is connected to the main flue economizer through a pipeline. One path of the main flue economizer is connected to the boiler's water-cooled wall through a third control valve, and the other path of the main flue economizer is connected to the boiler's water-cooled wall through a fourth control valve and the first-stage bypass economizer.

[0007] According to an embodiment of the present invention, the wide-proportion ammonia-blended combustion boiler system, by adding a bypass flue in the flue at the tail of the boiler, and sequentially arranging a first-stage bypass economizer and a second-stage bypass economizer in the bypass flue, as well as the setting of the feedwater system, can better absorb and utilize the heat in the flue gas generated after ammonia blending, and can better achieve the goal of efficient heat utilization within a wide range of ammonia blending ratios.

[0008] In addition, the wide-proportion ammonia-blending combustion boiler system according to the present invention may also have the following additional technical features: In some embodiments of the present invention, the high-pressure heater assembly includes: a first high-pressure heater, a second high-pressure heater, and a third high-pressure heater, wherein the second high-pressure heater is disposed between the first high-pressure heater and the main flue economizer, and the third high-pressure heater is located between the second high-pressure heater and the main flue economizer.

[0009] In some embodiments of the present invention, the water supply system further includes: a third-stage bypass economizer located in the bypass flue; one path of the first high-pressure heater is connected to the second high-pressure heater via a fifth control valve; and the other path of the first high-pressure heater is connected to the second high-pressure heater via a sixth control valve and the third-stage bypass economizer.

[0010] In some embodiments of the present invention, the third-stage bypass economizer is located between the first-stage bypass economizer and the second-stage bypass economizer.

[0011] In some embodiments of the present invention, the water supply system further includes: a fourth-stage bypass economizer located in the bypass flue; one path of the second high-pressure heater being connected to the third high-pressure heater via a seventh control valve; and the other path of the second high-pressure heater being connected to the third high-pressure heater via an eighth control valve and the fourth-stage bypass economizer.

[0012] In some embodiments of the present invention, the third-stage bypass economizer is located between the first-stage bypass economizer and the second-stage bypass economizer, and the fourth-stage bypass economizer is located between the first-stage bypass economizer and the third-stage bypass economizer.

[0013] In some embodiments of the present invention, the main flue is provided with at least one.

[0014] In some embodiments of the present invention, two main flues are provided, and the bypass flue is located between the two main flues.

[0015] In some embodiments of the present invention, the wide-proportion ammonia-blended combustion boiler system further includes: a main flue low-temperature reheater, wherein the main flue low-temperature reheater is disposed in the main flue and is located upstream of the economizer of the main flue in the flue gas flow direction.

[0016] In some embodiments of the present invention, the wide-proportion ammonia-blended combustion boiler system further includes a condensate system, which includes a condenser, a condensate pump, a condensing low-pressure economizer, and a multi-stage low-pressure heater. The condenser is connected to the condensate pump, one path of the condensate pump is connected to the multi-stage low-pressure heater through a ninth control valve, and the other path of the condensate pump is connected to the multi-stage low-pressure heater through a tenth control valve and the condensing low-pressure economizer. The multi-stage low-pressure heater is connected to the feedwater pump, wherein the condensing low-pressure economizer is located at the exhaust port of the flue.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 These are schematic diagrams of the water supply system in some embodiments.

[0019] Figure 2 These are cross-sectional views of flues in some embodiments.

[0020] Figure 3 These are cross-sectional views of flues in some embodiments.

[0021] Figure 4 These are schematic diagrams of the condensate system in some embodiments.

[0022] Figure label: 11. Main flue; 12. Bypass flue; 13. Flue gas damper; 21. First-stage bypass economizer; 22. Second-stage bypass economizer; 23. Third-stage bypass economizer; 24. Fourth-stage bypass economizer; 31. First high-pressure heater; 32. Second high-pressure heater; 33. Third high-pressure heater; 41. Economizer for main flue gas duct; 42. Feed water pump; 43. Water-cooled wall; 44. Low-temperature reheater for main flue gas duct; 51. First control valve; 52. Second control valve; 53. Third control valve; 54. Fourth control valve; 55. Fifth control valve; 56. Sixth control valve; 57. Seventh control valve; 58. Eighth control valve; 59. Ninth control valve; 60. Tenth control valve; 61. Condenser; 62. Condensate pump; 63. Condensing low-pressure economizer; 64. Multistage low-pressure heater. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] The following is for reference. Figures 1-4 A wide-proportion ammonia-blended combustion boiler system according to an embodiment of the present invention is described.

[0027] like Figure 1 and Figure 2 As shown, the wide-proportion ammonia-blended combustion boiler system according to an embodiment of the present invention includes a boiler system and a feedwater system. The boiler system has a flue, which includes a main flue 11 and a bypass flue 12. A flue gas damper 13 is provided at the inlet end of the bypass flue 12. The flue gas damper 13 is adapted to rotate to distribute the flue gas flow between the main flue 11 and the bypass flue 12. The feedwater system includes: a feedwater pump 42, a first-stage bypass economizer 21, a second-stage bypass economizer 22, a high-pressure heater assembly, and a main flue economizer 41. The main flue economizer 41 is located in the main flue 11, and the first-stage bypass economizer 21 and the second-stage bypass economizer 22 are both located in the bypass section. In flue 12, and in the direction of flue gas flow, the first-stage bypass economizer 21 is located upstream of the second-stage bypass economizer 22. One path of the feedwater pump 42 is connected to the high-pressure heater assembly through the first control valve 51, and the other path of the feedwater pump 42 is connected to the high-pressure heater assembly through the second control valve 52 and the second-stage bypass economizer 22. The high-pressure heater assembly is connected to the main flue economizer 41 through a pipeline. One path of the main flue economizer 41 is connected to the boiler water-cooled wall 43 through the third control valve 53, and the other path of the main flue economizer 41 is connected to the boiler water-cooled wall 43 through the fourth control valve 54 and the first-stage bypass economizer 21.

[0028] In other words, a bypass flue 12 can be added to the flue at the tail end of the boiler. A first-stage bypass economizer 21 and a second-stage bypass economizer 22 are arranged sequentially in the bypass flue 12. Each bypass economizer is equipped with a pipeline and valves. Specifically, the second-stage bypass economizer 22 is connected to the feed water pump 42 through a pipeline, and a second control valve 52 is installed on the pipeline to control the amount of water entering the second-stage bypass economizer 22. The first-stage bypass economizer 21 is connected to the main flue economizer 41 through a pipeline, and a fourth control valve 54 is installed on the pipeline to control the amount of water entering the first-stage bypass economizer 21. In addition, the first control valve 51 and the third control valve 53 are also used to control the amount of water, which will not be elaborated here.

[0029] Furthermore, when the amount of ammonia added is small, or when no ammonia is added, the flue gas damper 13 can close the bypass flue 12, and the high-pressure feedwater from the feedwater pump 42 can be directly sent to the water-cooled wall 43 after being heated by the high-pressure heater assembly and the main flue economizer 41.

[0030] As the ammonia dosage gradually increases, the flue gas damper 13 can be gradually opened, thereby gradually increasing the amount of flue gas entering the bypass flue 12. Simultaneously, the openings of the second control valve 52 and the fourth control valve 54 can be gradually increased, while the openings of the first control valve 51 and the third control valve 53 can be gradually decreased. Thus, the high-pressure feedwater from the feedwater pump 42 can be heated by the second-stage bypass economizer 22 and then sent to the high-pressure heater assembly. After being heated by the high-pressure heater assembly, it is sent to the main flue economizer 41. The feedwater enters the first-stage bypass economizer 21 from the outlet of the main flue economizer 41, is heated by the first-stage bypass economizer 21, and then sent to the water-cooled wall 43. Similarly, when the ammonia dosage gradually decreases, the opposite operation can be performed, for example, gradually closing the flue gas damper 13 and gradually decreasing the openings of the second control valve 52 and the fourth control valve 54, while gradually increasing the openings of the first control valve 51 and the third control valve 53. This will not be elaborated further here.

[0031] According to the present invention, the wide-proportion ammonia-blended combustion boiler system can better absorb and utilize the heat in the flue gas generated after ammonia blending by adding a bypass flue 12 in the flue at the tail of the boiler, arranging a first-stage bypass economizer 21 and a second-stage bypass economizer 22 in sequence in the bypass flue 12, and setting up a feedwater system, thereby achieving the goal of efficient heat utilization within a wide range of ammonia blending ratios.

[0032] In some embodiments of the present invention, such as Figure 1 As shown, the water supply system also includes: a first high-pressure heater 31, a second high-pressure heater 32 and a third high-pressure heater 33. The second high-pressure heater 32 is located between the first high-pressure heater 31 and the main flue economizer 41, and the third high-pressure heater 33 is located between the second high-pressure heater 32 and the main flue economizer 41.

[0033] In other words, after the first high-pressure heater 31 heats the feedwater, the second high-pressure heater 32 and the third heater can also heat the feedwater again. The three high-pressure heaters can effectively match the extraction of steam at different pressure levels from the turbine, allowing the feedwater temperature to gradually and steadily increase, reducing heat exchange losses and improving the unit's cycle thermal efficiency. Furthermore, it is understood that this application may also include a fourth high-pressure heater, a fifth high-pressure heater, etc., and this application does not impose any restrictions on this.

[0034] In some embodiments of the present invention, such as Figure 1 and Figure 2As shown, the water supply system also includes: a third-stage bypass economizer 23, which is located in the bypass flue 12; one path of the first high-pressure heater 31 is connected to the second high-pressure heater 32 through the fifth control valve 55; and the other path of the first high-pressure heater 31 is connected to the second high-pressure heater 32 through the sixth control valve 56 and the third-stage bypass economizer 23.

[0035] In other words, as the ammonia dosage gradually increases, the flue gas damper 13 can be gradually opened, thereby gradually increasing the amount of flue gas entering the bypass flue 12. At the same time, the opening of the second control valve 52, the fourth control valve 54, and the sixth control valve 56 can be gradually increased, while the opening of the first control valve 51, the third control valve 53, and the fifth control valve 55 can be gradually decreased. As a result, the high-pressure feedwater from the feedwater pump 42 can be heated by the second-stage bypass economizer 22 and then sent to the first high-pressure heater 31. After being heated by the first high-pressure heater 31, it is sent to the third-stage bypass economizer 23. After being heated by the third-stage bypass economizer 23, it is sent to the second high-pressure heater 32. After being heated by the second high-pressure heater 32, it is sent to the main flue economizer 41. The feedwater enters the first-stage bypass economizer 21 from the outlet of the main flue economizer 41, and after being heated by the first-stage bypass economizer 21, it is sent to the water-cooled wall 43. Similarly, when the amount of ammonia added gradually decreases, the opposite operation described above can be adopted. For example, gradually close the flue gas damper 13, and gradually reduce the opening of the second control valve 52, the fourth control valve 54 and the sixth control valve 56, while gradually increasing the opening of the first control valve 51, the third control valve 53 and the fifth control valve 55. This will not be elaborated here.

[0036] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, the third-stage bypass economizer 23 is located between the first-stage bypass economizer 21 and the second-stage bypass economizer 22.

[0037] In other words, when the flue gas enters the bypass flue 12, it can pass through the first-stage bypass economizer 21, the third-stage bypass economizer 23, and the second-stage bypass economizer 22 in sequence. That is, the heat carried in the flue gas is relatively high when passing through the first-stage bypass economizer 21 and relatively low when passing through the second-stage bypass economizer 22. Thus, through the above-mentioned water supply system settings and the sequential setting of the first-stage bypass economizer 21, the third-stage bypass economizer 23, and the second-stage bypass economizer 22, the waste heat in the flue gas can be better utilized, thereby better achieving the goal of efficient heat utilization within a wide range of ammonia doping ratios.

[0038] In some embodiments of the present invention, such as Figure 1 and Figure 2As shown, the water supply system also includes a fourth-stage bypass economizer 24, which is located in the bypass flue 12. One path of the second high-pressure heater 32 is connected to the third high-pressure heater 33 through the seventh control valve 57, and the other path of the second high-pressure heater 32 is connected to the third high-pressure heater 33 through the eighth control valve 58 and the fourth-stage bypass economizer 24.

[0039] In other words, as the ammonia dosage gradually increases, the flue gas damper 13 can be gradually opened, thereby gradually increasing the amount of flue gas entering the bypass flue duct 12. Simultaneously, the opening degrees of the second control valve 52, fourth control valve 54, sixth control valve 56, and eighth control valve 58 can be gradually increased, while the opening degrees of the first control valve 51, third control valve 53, fifth control valve 55, and seventh control valve 57 can be gradually decreased. Therefore, the high-pressure feedwater from the feedwater pump 42 can be heated by the second-stage bypass economizer 22 and then sent to the first high-pressure heater 31. After being heated by the high-pressure heater 31, the fuel is fed into the third-stage bypass economizer 23. After being heated by the third-stage bypass economizer 23, the fuel is fed into the second high-pressure heater 32. After being heated by the second high-pressure heater 32, the fuel is fed into the fourth-stage bypass economizer 24. After being heated by the fourth-stage bypass economizer 24, the fuel is fed into the third high-pressure heater 33. After being heated by the third high-pressure heater 33, the fuel is fed into the main flue economizer 41. Feedwater enters the first-stage bypass economizer 21 from the outlet of the main flue economizer 41. After being heated by the first-stage bypass economizer 21, the feedwater is fed into the water-cooled wall 43. Similarly, when the ammonia dosage gradually decreases, the opposite operation can be performed. For example, the flue gas damper 13 can be gradually closed, and the openings of the second control valve 52, the fourth control valve 54, and the sixth control valve 56 can be gradually reduced, while the openings of the first control valve 51, the third control valve 53, and the fifth control valve 55 can be gradually increased. This will not be elaborated here.

[0040] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, the third-stage bypass economizer 23 is located between the first-stage bypass economizer 21 and the second-stage bypass economizer 22, and the fourth-stage bypass economizer 24 is located between the first-stage bypass economizer 21 and the third-stage bypass economizer 23.

[0041] In other words, after the flue gas enters the bypass flue 12, it can pass through the first-stage bypass economizer 21, the fourth-stage bypass economizer 24, the third-stage bypass economizer 23, and the second-stage bypass economizer 22 in sequence. That is, the heat carried in the flue gas is relatively high when passing through the first-stage bypass economizer 21 and relatively low when passing through the second-stage bypass economizer 22. Thus, through the above-mentioned water supply system settings and the sequential setting of the first-stage bypass economizer 21, the fourth-stage bypass economizer 24, the third-stage bypass economizer 23, and the second-stage bypass economizer 22, the waste heat in the flue gas can be better utilized, thereby better achieving the goal of efficient heat utilization within a wide range of ammonia blending ratios.

[0042] In some embodiments of the present invention, at least one main flue 11 is provided, and when two main flues 11 are provided, the bypass flue 12 is located between the two main flues 11.

[0043] like Figure 2 As shown, there can be one main flue 11 and one bypass flue 12. The main flue 11 and the bypass flue 12 are arranged side by side, and a flue gas baffle 13 is installed at the inlet of the bypass flue 12.

[0044] like Figure 3 As shown, two main flues 11 can be provided, and one bypass flue 12 is provided. The bypass flue 12 is located between the two main flues 11. The two main flues 11 can better achieve the diversion of flue gas, which is conducive to making the flue gas distribution more uniform and improving the heat exchange efficiency. The bypass flue 12 arranged in the middle can better coordinate and regulate the two main flues 11, so as to flexibly distribute the flue gas flow with the two main flues 11.

[0045] In some embodiments of the present invention, such as Figure 1 As shown, the wide-proportion ammonia-blended combustion boiler system also includes: a main flue low-temperature reheater 44, which is located in the main flue 11 and is upstream of the economizer 41 in the flue gas flow direction.

[0046] In some embodiments of the present invention, such as Figure 4 As shown, the wide-proportion ammonia-blended combustion boiler system also includes a condensate system, which includes: a condenser 61, a condensate pump 62, a condensing low-pressure economizer 63, and a multi-stage low-pressure heater 64. The condenser 61 is connected to the condensate pump 62. One path of the condensate pump 62 is connected to the multi-stage low-pressure heater 64 through the ninth control valve 59, and the other path of the condensate pump 62 is connected to the multi-stage low-pressure heater 64 through the tenth control valve 60 and the condensing low-pressure economizer 63. The multi-stage low-pressure heater 64 is connected to the feedwater pump 42. The condensing low-pressure economizer 63 is located at the exhaust port of the flue.

[0047] In other words, when the amount of ammonia added increases, the ninth control valve 59 gradually decreases and the tenth control valve 60 gradually opens. The condensate pump 62 can increase the flow rate toward the condensing low-pressure economizer 63, thereby better reducing the flue gas temperature and condensing and cooling the water vapor in the flue gas, releasing the latent heat of vaporization of water in the flue gas.

[0048] For example, a condensing low-pressure economizer 63 can be added after the air preheater in the flue gas duct at the tail of the boiler. The condensing low-pressure economizer 63 adopts a partition structure as a whole. Corrosion-resistant ceramics can be arranged on the heat exchange surface on the flue gas side, and drainage holes are arranged at the bottom to make full use of the sensible heat of the boiler exhaust gas and the latent heat of moisture in the flue gas.

[0049] Other configurations and operations of the wide-proportion ammonia-blending combustion boiler system according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0050] In the description of this specification, references to terms such as "some embodiments," "optionally," "furthermore," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0051] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A wide-scale ammonia-doped combustion boiler system, characterized by, include: The boiler system has a flue, which includes a main flue (11) and a bypass flue (12). The inlet end of the bypass flue (12) is provided with a flue gas damper (13), which is adapted to rotate to distribute the flue gas flow of the main flue (11) and the bypass flue (12). The water supply system includes: a water pump (42), a first-stage bypass economizer (21), a second-stage bypass economizer (22), a high-pressure heater assembly, and a main flue economizer (41). The main flue economizer (41) is located in the main flue (11). The first-stage bypass economizer (21) and the second-stage bypass economizer (22) are both located in the bypass flue (12), and in the direction of flue gas flow, the first-stage bypass economizer (21) is located upstream of the second-stage bypass economizer (22). One path of the feedwater pump (42) is connected to the high-pressure heater assembly through the first control valve (51), and the other path of the feedwater pump (42) is connected to the high-pressure heater assembly through the second control valve (52) and the second-stage bypass economizer (22). The high-pressure heater assembly is connected to the main flue economizer (41) through a pipeline. One path of the main flue economizer (41) is connected to the boiler water-cooled wall (43) through the third control valve (53), and the other path of the main flue economizer (41) is connected to the boiler water-cooled wall (43) through the fourth control valve (54) and the first-stage bypass economizer (21).

2. The wide-proportion ammonia-blending combustion boiler system according to claim 1, characterized in that, The high-pressure heater assembly includes a first high-pressure heater (31), a second high-pressure heater (32), and a third high-pressure heater (33). The second high-pressure heater (32) is disposed between the first high-pressure heater (31) and the main flue economizer (41), and the third high-pressure heater (33) is located between the second high-pressure heater (32) and the main flue economizer (41).

3. The wide-proportion ammonia-blending combustion boiler system according to claim 2, characterized in that, The water supply system further includes: a third-stage bypass economizer (23), which is located in the bypass flue (12). One path of the first high-pressure heater (31) is connected to the second high-pressure heater (32) through a fifth control valve (55), and the other path of the first high-pressure heater (31) is connected to the second high-pressure heater (32) through a sixth control valve (56) and the third-stage bypass economizer (23).

4. The wide-proportion ammonia-blending combustion boiler system according to claim 3, characterized in that, The third-stage bypass economizer (23) is located between the first-stage bypass economizer (21) and the second-stage bypass economizer (22).

5. The wide-proportion ammonia-blending combustion boiler system according to claim 3, characterized in that, The water supply system further includes: a fourth-stage bypass economizer (24), which is located in the bypass flue (12); one path of the second high-pressure heater (32) is connected to the third high-pressure heater (33) through a seventh control valve (57); and the other path of the second high-pressure heater (32) is connected to the third high-pressure heater (33) through an eighth control valve (58) and the fourth-stage bypass economizer (24).

6. The wide-proportion ammonia-blending combustion boiler system according to claim 5, characterized in that, The third-stage bypass economizer (23) is located between the first-stage bypass economizer (21) and the second-stage bypass economizer (22), and the fourth-stage bypass economizer (24) is located between the first-stage bypass economizer (21) and the third-stage bypass economizer (23).

7. The wide-proportion ammonia-blending combustion boiler system according to claim 1, characterized in that, The main flue (11) is provided with at least one.

8. The wide-proportion ammonia-blending combustion boiler system according to claim 7, characterized in that, There are two main flues (11), and the bypass flue (12) is located between the two main flues (11).

9. The wide-proportion ammonia-blending combustion boiler system according to claim 1, characterized in that, Also includes: The main flue low-temperature reheater (44) is located in the main flue (11) and is located upstream of the main flue economizer (41) in the flue gas flow direction.

10. The wide-proportion ammonia-blending combustion boiler system according to claim 1, characterized in that, It also includes a condensate system, which comprises: a condenser (61), a condensate pump (62), a condensing low-pressure economizer (63), and a multi-stage low-pressure heater (64). The condenser (61) is connected to the condensate pump (62). One path of the condensate pump (62) is connected to the multi-stage low-pressure heater (64) through a ninth control valve (59), and the other path of the condensate pump (62) is connected to the multi-stage low-pressure heater (64) through a tenth control valve (60) and the condensing low-pressure economizer (63). The multi-stage low-pressure heater (64) is connected to the feedwater pump (42). The condensing low-pressure economizer (63) is installed at the exhaust port of the flue.

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