W-shaped flame boiler combustion system

Abstract

According to the W-shaped flame boiler combustion system, a plurality of combustors are arranged on the front wall face and the rear wall face of a boiler respectively, a coal mill is connected with a plurality of pulverized coal pipeline main pipes, and the other end of each pulverized coal pipeline main pipe is connected with a plurality of pulverized coal pipeline branch pipes through a pulverized coal distributor. And the other end of each pulverized coal pipeline branch pipe is connected with a burner. One coal mill is connected with a plurality of pulverized coal pipeline main pipes, and the pulverized coal distributors are arranged, so that pulverized coal is uniformly distributed in the pulverized coal pipeline main pipes and the pulverized coal pipeline branch pipes, and each combustor can obtain stable and appropriate pulverized coal supply. And meanwhile, the multiple combustors are uniformly distributed on the wall surface of the boiler, so that the pulverized coal can be more uniformly distributed in the hearth space of the boiler. By reasonably arranging the coal mills, the pulverized coal pipelines and the combustors, the uniformity of flames in the boiler can be improved on the premise that few coal mills operate, the combustion stability of the boiler is enhanced, and normal operation of the boiler under different load conditions is facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of boiler combustion, and particularly relates to a W-shaped flame boiler combustion system. Background Art

[0002] The W-shaped flame boiler has significant advantages in the field of pulverized coal air flow combustion by virtue of its unique arched furnace and double U-shaped flame structure. On the one hand, this structure effectively prolongs the residence time of the pulverized coal air flow in the furnace, providing more time conditions for the full combustion of pulverized coal; on the other hand, it can significantly increase the flue gas temperature at the flame root, which is extremely beneficial for the combustion of low-volatile pulverized coal. Therefore, the W-shaped flame boiler is widely used in anthracite combustion scenarios.

[0003] However, during the actual operation of the W-shaped flame boiler, especially during low-load operation, some problems have emerged. Its pulverized coal pipelines adopt an arrangement method where each pulverized coal pipeline corresponds to a burner. Affected by the layout characteristics of the burners in the furnace, the flame fullness in the furnace is poor, resulting in uneven distribution of the furnace heat load, and further causing a large deviation in the heat absorption of the water wall tubes, posing a risk of water wall cracking.

[0004] Taking a unit equipped with six coal mills as an example, when the unit load is low, due to the large width of the W-shaped flame boiler furnace, to ensure the flame fullness in the furnace, at least 4 coal mills need to be put into operation. However, the coal mills have large power and low output under this condition, which not only causes high energy consumption of the coal mills but also makes the system operation unstable.

[0005] To solve the above problems, the existing patent CN217928742U provides a solution, which relates to a tangentially fired combustion system with fewer coal mills. The system includes three coal mills 01 and four burners 03 arranged at the four corners of the boiler furnace. Each coal mill 01 is connected to four pulverized coal pipelines 02. Each burner 03 is composed of a housing 04, three pulverized coal nozzle compartments 06 formed by longitudinally arranging six partitions 05, and four secondary air nozzle compartments 07. And on both longitudinal sides of each pulverized coal nozzle compartment 06 are secondary air nozzle compartments 07, and the secondary air nozzle compartments are provided with secondary air inlets 08 and secondary air nozzles 09. Each pulverized coal nozzle compartment 06 is provided with a primary air duct 010, and the primary air duct 010 includes a pulverized coal pipeline connection 011, a pulverized coal equalizing pipe 012 with a tee structure, and two pulverized coal concentrators. The outlet of the pulverized coal pipeline connection 011 is connected to the inlet end of the pulverized coal equalizing pipe 012.

[0006] The above-mentioned existing patents mainly focus on the problem of the matching between three coal mills and four burners. By dividing the primary air generated by each coal mill into four pulverized coal pipes for output, and then allowing one of the pulverized coal pipes output by each coal mill to converge with each other and enter a burner, the problem of the mismatch in the number of coal mills and burners is solved. However, when the boiler is operating at low load, it is impossible to further reduce the number of coal mills, and the layout of the burners and coal mills cannot be flexibly changed. Summary of the Invention

[0007] The purpose of the present invention is to provide a combustion system for a W-shaped flame boiler, which can improve the uniformity of the flame in the furnace under the premise of operating fewer coal mills by reasonably arranging the coal mills, pulverized coal pipelines and burners.

[0008] To solve the above technical problems, the present invention provides a combustion system for a W-shaped flame boiler, including at least one coal mill, several main pulverized coal pipelines, several branch pulverized coal pipelines, several burners and a boiler, and further including a pulverized coal distributor;

[0009] One of the coal mills is respectively connected to one end of a plurality of the main pulverized coal pipelines, the other ends of each of the main pulverized coal pipelines are connected to one side of the pulverized coal distributor, the other side of the pulverized coal distributor is respectively connected to one end of a plurality of the branch pulverized coal pipelines, and the other ends of each of the branch pulverized coal pipelines are connected to one of the burners;

[0010] A plurality of the burners are evenly arranged on the wall surface of the boiler.

[0011] Optionally, in the above-mentioned combustion system for a W-shaped flame boiler, it further includes at least one of a resistance adjustment device, an expansion compensation device and a wind speed measurement device;

[0012] At least one of the resistance adjustment device, the expansion compensation device and the wind speed measurement device is connected in series on each of the branch pulverized coal pipelines.

[0013] Optionally, in the above-mentioned combustion system for a W-shaped flame boiler, it further includes valves, and the valves are connected in series on each of the branch pulverized coal pipelines and are close to the burners.

[0014] Optionally, in the above-mentioned combustion system for a W-shaped flame boiler, the valves are solenoid valves;

[0015] The combustion system for a W-shaped flame boiler further includes a control unit, and the control unit is respectively connected to the wind speed measurement device and the valves, and is used to control the opening and closing of the valves according to the measurement value of the wind speed measurement device.

[0016] Optionally, in the above-mentioned combustion system for a W-shaped flame boiler, the adjustment range of the resistance adjustment device is 0-100%;

[0017] And / or, the wind speed measurement range of the wind speed measurement device is 10m / s - 40m / s;

[0018] And / or, the powder quantity deviation of the pulverized coal distributor for each pulverized coal pipeline branch is 0 - 100%.

[0019] Optionally, in the above W - type flame boiler combustion system, the number of the coal mills is multiple;

[0020] And / or, the number of the main pulverized coal pipelines of each coal mill is 2 - 8;

[0021] And / or, the number of the pulverized coal pipeline branches connected to each main pulverized coal pipeline is 2 - 4;

[0022] And / or, 4 - 20 groups of the burners are arranged on each side wall of the boiler, and each group of the burners is two.

[0023] Optionally, in the above W - type flame boiler combustion system, the coal mill is a steel ball mill or a medium - speed mill;

[0024] And / or, the burner adopts a direct - current or swirling combustion mode.

[0025] Optionally, in the above W - type flame boiler combustion system, the sizes of all the main pulverized coal pipelines are the same.

[0026] Optionally, in the above W - type flame boiler combustion system, the pulverized coal pipeline branch is a pipeline with an equal cross - section, and the flow area of the pulverized coal pipeline branch is 1 / 4 - 1 / 2 times of the area of the main pulverized coal pipeline.

[0027] Optionally, in the above W - type flame boiler combustion system, multiple burners are respectively arranged on the front and rear wall surfaces of the boiler.

[0028] The present invention provides a W - type flame boiler combustion system, and its beneficial effects are as follows:

[0029] The design of connecting one coal mill to multiple main pulverized coal pipelines ensures that pulverized coal can be transported to each main pulverized coal pipeline with a stable and uniform flow rate. The setting of the pulverized coal distributor further guarantees the uniform distribution of pulverized coal in multiple pulverized coal pipeline branches, so that each burner can obtain a stable and appropriate amount of pulverized coal supply. During operation, the burner can continuously and stably burn, avoiding combustion interruption or fluctuation caused by uneven pulverized coal supply, enhancing the stability of the boiler combustion process, and being beneficial to the normal operation of the boiler under different load conditions. At the same time, the layout of multiple burners on the front and rear wall surfaces of the boiler enables pulverized coal to be more evenly distributed in the boiler furnace space. By reasonably arranging the coal mill, pulverized coal pipelines and burners, the uniformity of the flame in the furnace can be improved on the premise of operating fewer coal mills. Brief Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0031] Figure 1 It is a schematic structural diagram of a tangentially fired system with fewer coal mills in the prior art;

[0032] Figure 2 is Figure 1 the front view of a single burner in;

[0033] Figures 3 - 4 It is a schematic structural diagram of a W-shaped flame boiler combustion system provided by an embodiment of the present invention;

[0034] Figure 5 It is a schematic structural diagram of a pulverized coal pipeline provided by an embodiment of the present invention.

[0035] In Figures 1 - 2 :

[0036] 01 - Coal mill; 02 - Pulverized coal pipeline; 03 - Burner; 04 - Housing; 05 - Partition; 06 - Pulverized coal nozzle compartment; 07 - Secondary air nozzle compartment; 08 - Secondary air interface; 09 - Secondary air nozzle; 010 - Primary air duct; 011 - Pulverized coal pipeline connection; 012 - Pulverized coal equalizing pipe.

[0037] In Figures 3 - 5 :

[0038] 100 - Coal mill;

[0039] 210 - Main pulverized coal pipeline; 220 - Pulverized coal pipeline branch; 230 - Pulverized coal distributor;

[0040] 300 - Burner;

[0041] 400 - Boiler;

[0042] 510 - Resistance adjustment device; 520 - Expansion compensation device; 530 - Air velocity measurement device; 540 - Valve. Detailed Embodiments

[0043] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where 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 by referring to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0044] The core of the present invention is to provide a combustion system for a W-shaped flame boiler. By reasonably arranging the coal mills, coal powder pipelines, and burners, the uniformity of the flame in the furnace can be improved on the premise of operating fewer coal mills.

[0045] In order to enable those skilled in the art to better understand the technical solutions provided by the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0046] Specifically, please refer to Figures 3 - 5 A combustion system for a W-shaped flame boiler provided by the present invention includes at least one coal mill 100, a plurality of main coal powder pipelines 210, a plurality of branch coal powder pipelines 220, a plurality of burners 300, a boiler 400, and a coal powder distributor 230.

[0047] One coal mill 100 is respectively connected to one end of a plurality of main coal powder pipelines 210. The other end of each main coal powder pipeline 210 is connected to one side of the coal powder distributor 230. The other side of the coal powder distributor 230 is respectively connected to one end of a plurality of branch coal powder pipelines 220. The other end of each branch coal powder pipeline 220 is connected to a burner 300.

[0048] A plurality of burners 300 are evenly arranged on the wall surface of the boiler 400, so that the coal powder can be more evenly distributed in the furnace space of the boiler 400, increasing the contact area and mixing degree between the coal powder and air. This evenly distributed combustion method helps to improve the combustion efficiency of the coal powder, enables the chemical energy in the fuel to be more fully converted into heat energy, reduces the generation of incomplete combustion products such as carbon monoxide and hydrocarbons, and improves the overall energy utilization efficiency of the boiler.

[0049] A combustion system for a W-shaped flame boiler provided by the present invention arranges a plurality of burners 300 on the front and rear wall surfaces of the boiler 400 respectively. One coal mill 100 is respectively connected to a plurality of main coal powder pipelines 210. The other end of each main coal powder pipeline 210 is connected to a plurality of branch coal powder pipelines 220 through the coal powder distributor 230. The other end of each branch coal powder pipeline 220 is respectively connected to a burner 300.

[0050] The design of connecting a coal mill 100 to multiple main pulverized coal pipelines 210 ensures that pulverized coal can be transported to each main pulverized coal pipeline 210 with a stable and uniform flow rate. The setting of the pulverized coal distributor 230 further guarantees the uniform distribution of pulverized coal in multiple pulverized coal pipeline branches 220, so that each burner 300 can obtain a stable and appropriate supply of pulverized coal. During operation, the burner 300 can continuously and stably burn, avoiding combustion interruption or fluctuations caused by uneven pulverized coal supply, enhancing the stability of the combustion process of the boiler 400, and being conducive to the normal operation of the boiler 400 under different load conditions. At the same time, the uniform layout of multiple burners 300 on the wall of the boiler 400 enables the pulverized coal to be more evenly distributed in the furnace space of the boiler 400. By reasonably arranging the coal mill 100, pulverized coal pipelines and burners 300, the uniformity of the flame in the furnace can be improved on the premise of operating fewer coal mills 100, reducing the power consumption of the coal mill and enhancing the operating stability of the coal mill.

[0051] In a specific embodiment, the solution further includes at least one of a resistance adjusting device 510, an expansion compensation device 520, and a wind speed measuring device 530.

[0052] At least one of the resistance adjusting device 510, the expansion compensation device 520, and the wind speed measuring device 530 is connected in series to each pulverized coal pipeline branch 220.

[0053] It should be noted that during the boiler combustion process, a certain amount of air needs to be sent into the boiler furnace to support the combustion of fuel. The pulverized coal distributor 230 can evenly distribute the pulverized coal to each burner 300, making the amount of pulverized coal in each burner 300 consistent, thereby ensuring the uniformity and stability of combustion.

[0054] The resistance adjusting device 510 can control the flow rate of air in the channel where the pulverized coal pipeline branch 220 is located by changing its own resistance. Appropriate resistance adjustment helps to form a good aerodynamic condition, enabling the fuel and air to be fully mixed. Good mixing can make the combustion reaction more complete and improve the combustion efficiency. Specifically, the adjustment range of the resistance adjusting device 510 is 0 - 100%.

[0055] During the operation of the boiler, components such as the heating surface and pipelines will expand due to the increase in temperature and contract when the temperature decreases. The expansion compensation device 520 can provide a certain free expansion and contraction space, thereby relieving the stress generated by thermal expansion and contraction. The expansion compensation device 520 can also ensure that pipelines, equipment, etc. in the boiler system can still maintain normal connection and sealing under the condition of thermal expansion and contraction, and maintain the normal operation of the system. The expansion compensation device 520 can perform three-dimensional compensation. For example, expansion compensation devices such as bellows expansion joints, sleeve compensators, and non-metallic compensators.

[0056] The wind speed measuring device 530 can monitor the air flow velocity entering the boiler furnace in real time, providing an accurate basis for controlling the air volume in the combustion process. By adjusting the wind speed, it ensures an appropriate amount of air required for fuel combustion, avoiding incomplete combustion caused by insufficient air or a decrease in combustion temperature caused by excessive air, thereby improving the combustion efficiency. In a boiler system with multiple burners, the wind speed measuring device 530 can monitor the wind speed of each burner 300, ensuring that each burner 300 can obtain a uniform air supply. This helps to achieve combustion uniformity, prevent local overheating or underheating of combustion, and improve the stability and overall efficiency of combustion. Specifically, the wind speed measurement range of the wind speed measuring device 530 is 10 - 40 m / s.

[0057] The pulverized coal distributor 230 can distribute the pulverized coal amount in each branch pipe 220 of the pulverized coal pipeline. The pulverized coal amount deviation in each pulverized coal pipeline is 0 - 100%. It can flexibly adjust the pulverized coal supply amount of each burner 300 according to the actual combustion demand, further improving the combustion efficiency of the pulverized coal.

[0058] A coal mill 100 is connected to multiple main pipes 210 of the pulverized coal pipeline. The pulverized coal distributor 230 evenly distributes the pulverized coal into each branch pipe 220 of the pulverized coal pipeline. The design with a pulverized coal amount deviation of 0 - 100% in each powder pipe enables each burner 300 to obtain a stable, appropriate and flexibly adjustable pulverized coal supply. During operation, the burner 300 can continuously and stably burn, avoiding combustion interruption or fluctuation caused by uneven pulverized coal supply, enhancing the stability of the combustion process of the boiler 400, and being beneficial to the normal operation of the boiler under different load conditions.

[0059] This solution also includes a valve 540. The valve 540 is connected in series on each branch pipe 220 of the pulverized coal pipeline and is close to the burner 300. For example, Figure 5 As shown, the channel flow rate in each branch pipe 220 of the pulverized coal pipeline is controlled by the valve 540.

[0060] Furthermore, a control unit can be additionally set to control each component. Specifically, the valve 540 is a solenoid valve. The W-type flame boiler combustion system also includes a control unit. The control unit is respectively connected to the wind speed measuring device 530 and the valve 540, and is used to control the opening and closing of the valve 540 according to the measurement value of the wind speed measuring device 530.

[0061] The control unit accurately adjusts the pulverized coal flow rate in each branch pipe 220 of the pulverized coal pipeline by controlling the opening and closing degree of the valve 540 according to the combustion condition and load demand. When the load changes, it realizes rapid and accurate adjustment of the pulverized coal supply, ensures the combustion efficiency and stability, and avoids problems such as incomplete combustion caused by untimely or excessive pulverized coal supply.

[0062] On the basis of the above specific embodiments, the number of coal mills 100 is multiple, specifically 2 - 8 units. The number of main pulverized coal pipelines 210 of each coal mill 100 is 2 - 8. Each pulverized coal pipeline branch 220 is correspondingly connected to a burner 300. 4 - 20 groups of burners 300 are arranged on each side wall of the boiler 400, and each group of burners 300 is 2 - 4 units.

[0063] Specifically, according to the actual working condition load of the boiler, the number of each component can be adaptively selected.

[0064] As Figure 4 and Figure 5 shown, the number of coal mills 100 is two, and the number of burners 300 is eight. Two main pulverized coal pipelines 210 are arranged at the outlet of each coal mill 100. Two pulverized coal pipeline branches 220 are connected to each main pulverized coal pipeline 210. The flow area of each pulverized coal pipeline branch 220 is 1 / 2 of that of the main pulverized coal pipeline 210. 4 groups of burners 300 are arranged on the front and rear walls of the boiler respectively, and the number of each group of burners 300 is 2. The pulverized coal pipeline branches 220 are connected to each single burner 300 one by one.

[0065] Through a reasonable layout of the coal mill 100, pulverized coal pipelines and burners 300, the uniformity of the flame in the furnace can be improved on the premise of operating fewer coal mills 100, the power consumption of the coal mill 100 can be reduced, and the operating stability of the coal mill can be improved.

[0066] In the specific embodiment, the coal mill 100 is a ball mill or a medium - speed mill. The characteristics of the ball mill are simple structure, reliable operation and strong adaptability, especially suitable for hard coal types. While the medium - speed mill is famous for high efficiency, energy saving and compactness, which meets the requirements of modern high - efficiency boilers.

[0067] In the specific embodiment, the sizes of the main pulverized coal pipelines 210 are the same. Of course, the diameters of the pulverized coal pipeline branches 220 can also be designed to be the same. So as to more conveniently adjust the flow rate of each pulverized coal pipeline branch 220.

[0068] In the specific embodiment, the pulverized coal pipeline branch 220 is a pipeline with a constant cross - section, and the flow area of the pulverized coal pipeline branch 220 is 1 / 4 - 1 / 2 times that of the main pulverized coal pipeline 210.

[0069] Multiple burners 300 are respectively arranged on the front and rear walls of the boiler 400. It should be noted that in order to more clearly show the relationship between the burners 300 and each pulverized coal pipeline and coal mill 100, Figure 3 and Figure 4The shown boiler 400 is a front and rear wall expansion view, and all the burners 300 shown in the figure are respectively located on the front and rear walls of the boiler 400. A main pulverized coal pipeline 210 is divided into several pulverized coal pipeline branches 220 through a pulverized coal distributor 230 and respectively enter the burners 300 distributed at different positions in the boiler furnace. Each burner 300 is connected to the water wall of the boiler, with multiple burner nozzles opened and evenly arranged on the furnace, and each pulverized coal pipeline is arranged outside the boiler.

[0070] Through the separation of the pulverized coal pipeline and the grouped arrangement of the burners, the present invention improves the uniform distribution of the burners put into operation in the boiler during low-load operation, ensures the uniformity of the internal heat load of the furnace during low-load operation, and solves problems such as overheating of the boiler heating surface caused by uneven heat load. At the same time, thanks to the improvement of the internal heat load uniformity of the furnace, the boiler can reduce the number of coal mills running under low load, and the running load of a single coal mill is increased. While reducing the power consumption of the coal mill, the reliability of the coal mill operation is improved.

[0071] In the description of the present application, it should be understood that for the orientation description, such as the orientation or positional relationship indicated by up, down, front, rear, left, right, etc. is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying 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 to the present application.

[0072] As shown in the present application and the claims, unless the context clearly indicates an exception, words such as "a", "an", "one", and / or "the" are not specifically singular and may also include plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements. The element defined by the statement "comprising one..." does not exclude the existence of another same element in the process, method, commodity or device including the element.

[0073] Among them, in the description of the embodiments of the present application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B; the "and / or" in this article is only a description of the association relationship of the associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0074] In the description of the present application, unless otherwise clearly defined, words such as setting, installing, and connecting should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present application in combination with the specific content of the technical solution.

[0075] In this specification, the various embodiments are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts among the various embodiments can be referred to each other.

[0076] Specific examples are used herein to illustrate the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A W-shaped flame boiler combustion system, comprising at least one coal mill (100), a plurality of main pulverized coal pipelines (210), a plurality of pulverized coal pipeline branches (220), a plurality of burners (300) and a boiler (400), characterized in that, It also includes a pulverized coal distributor (230); One of the coal mills (100) is respectively connected to one end of a plurality of main pulverized coal pipelines (210). The other end of each main pulverized coal pipeline (210) is connected to one side of the pulverized coal distributor (230). The other side of the pulverized coal distributor (230) is respectively connected to one end of a plurality of branch pulverized coal pipelines (220). The other end of each branch pulverized coal pipeline (220) is connected to one burner (300); A plurality of the burners (300) are evenly arranged on the wall surface of the boiler (400).

2. The W-shaped flame boiler combustion system according to claim 1, characterized in that, It also includes at least one of a resistance adjusting device (510), an expansion compensation device (520) and a wind speed measuring device (530); At least one of the resistance adjusting device (510), the expansion compensation device (520) and the wind speed measuring device (530) is connected in series on each branch pulverized coal pipeline (220).

3. The W-type flame boiler combustion system according to claim 2, characterized in that, It also includes a valve (540). The valve (540) is connected in series on each branch pulverized coal pipeline (220) and is close to the burner (300).

4. The W-type flame boiler combustion system according to claim 3, characterized in that, The valve (540) is a solenoid valve; The W-type flame boiler combustion system also includes a control unit. The control unit is respectively connected to the wind speed measuring device (530) and the valve (540), and is used to control the opening and closing of the valve (540) according to the measured value of the wind speed measuring device (530).

5. The W-shaped flame boiler combustion system according to claim 2, characterized in that, The adjustment range of the resistance adjusting device (510) is 0 - 100%; And / or, the wind speed measurement range of the wind speed measuring device (530) is 10 m / s - 40 m / s; And / or, the powder quantity deviation of the pulverized coal distributor (230) for each branch pulverized coal pipeline (220) is 0 - 100%.

6. The W-shaped flame boiler combustion system according to claim 1, wherein, The number of the coal mills (100) is multiple; And / or, the number of main pulverized coal pipelines (210) for each coal mill (100) is 2 - 8; And / or, the number of branch pulverized coal pipelines (220) connected to each main pulverized coal pipeline (210) is 2 - 4; And / or, 4 - 20 groups of the burners (300) are arranged on each side wall of the boiler (400), and each group of the burners (300) has two.

7. The W-shaped flame boiler combustion system according to claim 1, characterized in that, The coal mill (100) is a steel ball mill or a medium-speed mill; And / or, the burner (300) adopts a direct current or swirl combustion mode.

8. The W-type flame boiler combustion system according to claim 1, wherein, The sizes of all the main pulverized coal pipelines (210) are the same.

9. The W-type flame boiler combustion system according to claim 1, wherein, The branch pulverized coal pipeline (220) is a pipeline with a constant cross-section. The flow area of the branch pulverized coal pipeline (220) is 1 / 4 - 1 / 2 times the area of the main pulverized coal pipeline (210).

10. The W-type flame boiler combustion system according to claim 1, characterized in that, A plurality of the burners (300) are respectively arranged on the front and rear wall surfaces of the boiler (400).

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