A tangentially fired liquid slagging boiler

Abstract

The embodiment of the present application provides a tangentially-fired liquid slagging boiler, which comprises a boiler body and a burner, the boiler body is internally provided with a hearth and a molten slag combustion chamber, the molten slag combustion chamber has an inlet and an outlet, the outlet of the molten slag combustion chamber is communicated with the hearth, the molten slag combustion chamber is multiple, the multiple molten slag combustion chambers are surrounded at the outer circumferential side of the hearth, and the center line of the outlet of each molten slag combustion chamber is a tangent of an imaginary tangent circle, the burner is connected with the boiler body so that the outlet of the burner is communicated with the inlet of the molten slag combustion chamber. The tangentially-fired liquid slagging boiler has the advantages that slagging and fouling of the heating surface are not prone to occur in the boiler body, and the ash content of flue gas is low.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of combustion boiler, in particular to a tangentially fired liquid slagging boiler. BACKGROUND

[0002] The liquid slagging boiler is a boiler that the slag generated after the fuel is burned is melted into liquid state at high temperature in the slag melting chamber and discharged from the furnace.

[0003] In the related art, the slag melting chamber and the burner of the liquid slagging boiler are arranged vertically, in other words, the slag melting chamber is arranged directly below the burner, and the whole of the burner and the slag melting chamber is arranged horizontally side by side with the furnace cavity of the boiler body, and the outlet of the burner is communicated with the slag melting chamber and the furnace cavity. The liquid slagging boiler with such arrangement structure has the problems of insufficient combustion, more ash in the flame and flue gas, resulting in slagging and fouling of the heating surface in the boiler body, and the flue gas passage of the heating surface is blocked due to the large amount of ash in the flue gas. SUMMARY

[0004] The present application aims to at least solve one of the technical problems in the related art. To this end, the embodiments of the present application provide a tangentially fired liquid slagging boiler, which has the advantages of less slagging and fouling of the heating surface in the boiler body, and low ash content in the flue gas.

[0005] The tangentially fired liquid slagging boiler according to the embodiments of the present application comprises:

[0006] A boiler body, the boiler body is provided with a furnace and a slag melting combustion chamber, the slag melting combustion chamber has an inlet and an outlet, the outlet of the slag melting combustion chamber is communicated with the furnace, and the slag melting combustion chamber is multiple, the multiple slag melting combustion chambers are arranged around the outer periphery of the furnace, and the center line of the outlet of each slag melting combustion chamber is a tangent of an imaginary tangent circle.

[0007] A burner, the burner is connected with the boiler body so that the outlet of the burner is communicated with the inlet of the slag melting combustion chamber.

[0008] In the tangentially-fired liquid slagging boiler of the embodiment of the present application, the coal, especially the high-alkali coal, is ignited and burned in the burner, and then enters the molten slag combustion chamber, where the coal is burned in the liquid slag film combustion mode, and in the molten slag combustion chamber, the alkali metal and the liquid ash slag perform a series of physicochemical reactions to achieve the solidification and capture of a certain proportion of the alkali metal, thereby greatly reducing the alkali metal content and the ash content in the high-temperature flame, and then the coal flame passes through the molten slag combustion chamber and enters the furnace for tangentially-fired combustion, and is burned out in the furnace. Since the coal flame needs to pass through the molten slag combustion chamber, the capture effect of the molten slag combustion chamber can better act on the coal, thereby effectively removing the ash components of the coal, and the unburned coal particles and combustible gases and other components discharged from the molten slag combustion chamber are rotated and intensified in the furnace in a tangential manner to make the coal fully burn out, so that the boiler body is less likely to have slagging and heating surface fouling, and the ash content of the flue gas is low.

[0009] In some embodiments, the furnace extends in an up-down direction, the furnace is respectively provided with the molten slag combustion chamber extending in a first direction on both sides of the furnace in the first direction, the first direction is orthogonal to the up-down direction, the furnace is respectively provided with the molten slag combustion chamber extending in a second direction on both sides of the furnace in the second direction, the second direction is orthogonal to the first direction and the up-down direction, the outlet and the inlet of the molten slag combustion chamber are located on the same straight line, and the opening direction of the outlet of the molten slag combustion chamber and the opening direction of the inlet are opposite; and / or

[0010] The burner is a cyclone burner.

[0011] In some embodiments, the furnace includes a lower furnace and an upper furnace, the lower furnace is in communication with the upper furnace and located below the upper furnace, the outlet of the molten slag combustion chamber is in communication with the lower furnace, the boiler body has a recess, the recess surrounds the boiler body around a central axis of the boiler body, and the recess is located at the communication position of the lower furnace and the upper furnace.

[0012] In some embodiments, the tangentially-fired liquid slagging boiler further includes a slag capturing device, the slag capturing device is connected to the boiler body and arranged at the outlet of the molten slag combustion chamber.

[0013] In some embodiments, the slag capturing device includes a slag capturing pipe bundle, the slag capturing pipe bundle includes a plurality of parallel and spaced slag capturing pipes, and the slag capturing pipes contain a cooling medium.

[0014] In some embodiments, the extension direction of the slag capturing pipe bundle and the up-down direction have an inclination angle, and the inclination angle is less than 30°.

[0015] In some embodiments, the tangentially-fired liquid slagging boiler further comprises a liquid slag pocket and a water tank, the liquid slag pocket having an inlet and an outlet, the liquid slag pocket being connected to the boiler body so that the molten slag combustion chamber is in communication with the inlet of the liquid slag pocket, one end of the slag catcher being arranged on the inner circumferential surface of the liquid slag pocket, and the outlet of the liquid slag pocket being in communication with the water tank.

[0016] In some embodiments, the tangentially-fired liquid slagging boiler further comprises a slag extractor, the slag extractor being connected to the water tank to extract slag particles in the water tank.

[0017] In some embodiments, the bottom of the boiler body has a dry slag pocket, the internal space of the dry slag pocket being in communication with the furnace.

[0018] In some embodiments, the tangentially-fired liquid slagging boiler further comprises a sootblower and / or an overfire air device, the boiler body comprising a membrane water wall, the membrane water wall surrounding the furnace, and the membrane water wall being provided with a first opening and / or a second opening in communication with the furnace.

[0019] The sootblower comprises a steam nozzle, a steam pipe and an extension mechanism, the extension mechanism being arranged on the outer wall surface of the membrane water wall, the extension mechanism being provided with the steam nozzle, and the extension mechanism driving the steam nozzle to enter or exit the furnace through the first opening, the steam nozzle being in communication with the steam pipe.

[0020] The overfire air device is arranged on the outer wall surface of the membrane water wall, and the air outlet of the overfire air device is arranged in the second opening. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a structural schematic diagram of a tangentially-fired liquid slagging boiler according to an embodiment of the present application;

[0022] Figure 2 is Figure 1 a schematic diagram of the arrangement of a molten slag combustion chamber.

[0023] REFERENCE NUMERALS:

[0024] 1. boiler body; 101. furnace; 1011. lower furnace; 1012. upper furnace; 102. molten slag combustion chamber; 103. recess; 104. dry slag pocket; 105. flue gas passage; 2. burner; 3. slag catcher; 4. liquid slag pocket; 5. water tank; 6. slag extractor; 7. sootblower; 8. overfire air device; 9. screen heating surface; 901. front screen superheater; 902. rear screen superheater; 903. high-temperature superheater; 904. high-temperature reheater; 905. low-temperature reheater; 11. economizer; 12. air preheater; 13. slag well. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0026] Please refer to the following Figure 1 -Attached Figure 2 A liquid slagging boiler using a tangentially fired method according to an embodiment of the present invention is described.

[0027] like Figures 1-2 As shown, the liquid slag discharge boiler with tangential combustion mode according to the embodiment of the present invention includes a boiler body 1 and a burner 2.

[0028] A furnace 101 and a slag combustion chamber 102 are provided in the boiler body 1. The slag combustion chamber 102 has an inlet and an outlet. The outlet of the slag combustion chamber 102 is connected to the furnace 101. The coal ignites and burns in the cyclone burner 2 and the slag combustion chamber 102, and most of the ash components are removed under the capture effect of the slag combustion chamber 102. The coal flame with most of the ash components removed enters the furnace 101 through the outlet of the slag combustion chamber, and then the coal powder is burned in the furnace 101.

[0029] There are multiple slag combustion chambers 102, which surround the outer periphery of the furnace 101, and the center line of the outlet of each slag combustion chamber 102 is a tangent to the same imaginary tangent circle. Figure 2 As shown, the dotted line in the figure is an imaginary tangent circle and a tangent of the imaginary tangent circle. The projection axis of the center of the imaginary tangent circle on the cross section of the furnace is parallel to or coincides with the center line of the cross section of the furnace 101. In other words, the center of the imaginary tangent circle can be on the center line of the furnace 101, or it can have a certain deviation distance from the center line of the furnace 101. The front, rear, left and right sides of the furnace 101 are each provided with a slag combustion chamber 102. The opening direction of the outlet of the slag combustion chamber 102 is all toward the furnace 101. The coal flames discharged from the four slag combustion chambers 102 move along the tangent direction of the imaginary tangent circle, and then converge in the furnace 101 and rotate and rise along the circumference of the imaginary tangent circle to burn. During the rotating combustion, the coal powder is evenly mixed, flames of different temperatures support each other and strong mixing occurs between the flames, so that the coal particles and the combustible components in the flue gas are fully burned. Preferably, the temperature of the outlet of the slag combustion chamber 102 is 1500℃~1600℃.

[0030] The combustor 2 is connected with the boiler body 1 so that the outlet of the combustor 2 is communicated with the inlet of the slag burning chamber 102. The combustor 2 ignites and burns the coal, and the coal flame has sufficient jet rigidity by the power field characteristics of the combustor 2, so that the coal flame can pass through the slag burning chamber and be injected into the furnace 101.

[0031] In the related art, the slag chamber and the combustor of the liquid slag discharge boiler are vertically arranged, in other words, the slag chamber is arranged directly below the combustor, and the combustor and the slag chamber are arranged side by side with the furnace cavity of the boiler body in the horizontal direction, and the outlet of the combustor is communicated with the slag chamber and the furnace cavity. The pulverized coal is ignited in the combustor and then moves downward into the slag chamber, stays in the slag chamber for a short time to separate the ash and slag, and then moves upward and turns into the furnace cavity to burn out, thereby generating heat.

[0032] However, the inventors have found that the conventional liquid slag discharge boiler in the related art has the problems of slagging and heating surface fouling when high-alkali coal is burned, and the flue gas passage between the boiler water wall and the screen heating surface is blocked due to the high concentration of alkali metals and ash and other components in the flue gas. In order to avoid the problems of slagging and heating surface fouling of the boiler caused by the ash of high-alkali coal, and even the heat exchange barrier and flue blockage that harm the normal operation of the boiler, the boiler body and the flue gas passage need to be cleaned regularly to maintain the normal operation of the boiler.

[0033] The inventors have found through in-depth research that the liquid slag discharge boiler and the solid slag discharge tangentially fired pulverized coal boiler in the related art both have the problem of insufficient adaptability when burning high-alkali coal, including the defects of the short distance between the heating surface of the conventional liquid slag discharge boiler and the high-temperature flue gas, insufficient alkali metal capture ability, weak anti-fouling ability of the furnace, insufficient air staging, and low burnout rate. The conventional solid slag discharge tangentially fired pulverized coal boiler also has the problems of insufficient alkali metal capture ability, high ash content in the flue gas, slagging in the furnace and the heating surface, heating surface fouling, and flue gas passage blockage, which harm the safe operation of the boiler. The reason is that these two types of boilers are not fully designed according to the coal quality characteristics of high-alkali coal, and cannot fully meet the needs of safe, clean and efficient combustion of high-alkali coal.

[0034] To this end, the inventor proposes a tangentially-fired liquid slagging boiler, in which high-alkali coal is first combusted in a slag melting chamber after being ignited by a burner, and the alkali metal is solidified and captured to intercept most of the ash components in the form of liquid slag outside the furnace, and the coal flame with low ash content penetrates the slag melting chamber into the furnace for tangentially-fired combustion and is combusted in the furnace.

[0035] It should be noted that high-alkali coal refers to coal with an alkali metal proportion greater than 4%, which has problems such as low ash melting point, strong slagging and fouling, and easy ash blocking in the tail flue, which seriously endanger the safe operation of the boiler. Therefore, the liquid slagging boiler and the conventional solid slagging boiler in the related art have serious problems of slagging, heating surface fouling, and flue gas passage blocking when burning high-alkali coal, and even cause the boiler in the related art to have operational safety hazards. The tangentially-fired liquid slagging boiler of the embodiment of the present application can fully capture and discharge the alkali metal and ash components in the early stage of combustion, and therefore is not prone to slagging, heating surface fouling, and flue gas passage blocking when burning high-alkali coal. The tangentially-fired liquid slagging boiler of the embodiment of the present application is suitable for not only high-alkali coal with an alkali metal proportion greater than 4%, but also ordinary coal with an alkali metal proportion less than 2%.

[0036] In addition, the tangentially-fired liquid slagging boiler of the embodiment of the present application has the advantage of being easy to manufacture. The solid slagging boiler in the related art can be modified to obtain the tangentially-fired liquid slagging boiler of the embodiment of the present application. Specifically, a plurality of slag melting chambers are arranged around the pulverized coal boiler, and the slag melting chambers are communicated with the furnace of the solid slagging boiler, so that the solid slagging boiler in the related art can be modified to the tangentially-fired liquid slagging boiler of the embodiment of the present application. Thus, the alkali metal is first captured and solidified through the physicochemical reaction at high temperature of the mineral, and then the ash content in the flue gas in the later stage of the furnace is greatly reduced through the ash capture and discharge of the slag melting chamber, and the high-temperature flue gas is sufficiently cooled through the high-furnace design of the solid slagging boiler, and the dry slag condensed in the later stage is discharged from the furnace through the dry slagging method.

[0037] In some embodiments, the furnace 101 extends in the up-down direction, and the furnace 101 is in the first direction (eg Figure 2 The left and right directions shown in FIG. 1 are respectively provided with slag combustion chambers 102 extending in a first direction, the first direction being orthogonal to the up and down directions, and the furnace 101 is provided with a slag combustion chamber 102 extending in a second direction (as shown in FIG. Figure 2 A slag combustion chamber 102 extending along the second direction is provided on both sides of the front-to-back direction (as shown), the second direction is orthogonal to the first direction and the up-down direction, the outlet and inlet of the slag combustion chamber 102 are located on the same straight line, and the opening direction of the outlet of the slag combustion chamber 102 is opposite to the opening direction of the inlet.

[0038] like Figure 2 As shown, slag combustion chambers 102 are provided on the front, rear, left and right sides of the furnace 101, wherein the front slag combustion chamber 102 and the rear slag combustion chamber 102 extend in the front-to-back direction, the front slag combustion chamber 102 has an inlet at the front end and an outlet at the rear end, the rear slag combustion chamber 102 has an inlet at the rear end and an outlet at the front end, the center line of the outlet of the front slag combustion chamber 102 is located to the right of the center of the imaginary tangent circle, and the rear slag combustion chamber 102 has an inlet at the rear end and an outlet at the front end. The centerline of the outlet of burner 2 is located to the left of the center of the imaginary tangential circle. The left slag combustion chamber 102 and the right slag combustion chamber 102 extend in the left-right direction. The left slag combustion chamber 102 has an inlet on the left and an outlet on the right, while the right slag combustion chamber 102 has an inlet on the right and an outlet on the left. The centerline of the outlet of the left slag combustion chamber 102 is located in front of the imaginary tangential circle, while the centerline of the outlet of the right slag combustion chamber 102 is located in the rear of the imaginary tangential circle. The coal flame discharged from burner 2 moves along the extension direction of the slag combustion chamber 102 connected to burner 2, enters the furnace 101 after passing through the slag combustion chamber 102, and then rotates clockwise along the circumference of the imaginary tangential circle.

[0039] The distance between the outlet of the front slag combustion chamber 102 and the outlet of the rear slag combustion chamber 102 is preferably 2m-4m, and the distance between the outlet of the left slag combustion chamber 102 and the outlet of the right slag combustion chamber 102 is preferably 2m-4m, so as to ensure that there is a combustion space for sufficient combustion in the furnace 101, and meet the time for sufficient combustion of coal powder and a relatively stable temperature environment.

[0040] Since the coal combustion flame discharged by the burner needs to pass through the slag burning chamber along the extension direction of the slag burning chamber before entering the hearth, the gas flame and the coal particles have a long residence time and a long moving path in the slag burning chamber, which is beneficial to the capture and solidification of alkali metals in the liquid slag burning environment. The alkali metal and ash capture effect of the slag burning chamber can fully act on the coal combustion flame, so that most of the alkali metals and ash components in the high-alkali coal form liquid slag and are discharged, effectively reducing the content of alkali metals and ash entering the hearth. When the pulverized coal is high-alkali coal, more than 50% of the alkali metals in the high-alkali coal are captured in the slag burning chamber, and then form liquid slag and are discharged, thereby reducing the content of alkali metals entering the hearth and avoiding the situation of slagging, heating surface fouling and flue gas passage blockage.

[0041] It can be understood that the slag burning chamber is not limited to one layer in the up-down direction. In other embodiments, the slag burning chamber is provided with multiple layers in the up-down direction, and each layer has four slag burning chambers located at the front side, the rear side, the left side and the right side of the hearth.

[0042] It can be understood that the extension direction of the slag burning chamber is not limited to being orthogonal to the up-down direction. In other embodiments, due to construction or installation reasons, the extension direction of the slag burning chamber has a small included angle with the horizontal direction, and at this time the imaginary tangent circle has a small included angle with the horizontal direction.

[0043] In some embodiments, the burner 2 is a cyclone burner.

[0044] Compared with other structures of the burner, the cyclone burner can generate a stronger liquid slag film burning environment in the slag burning chamber, which can improve the capture effect of the slag burning chamber on the ash components and alkali metals, and on the other hand, can modify the ash during coal combustion into coal ash with lower fouling tendency.

[0045] In some embodiments, the hearth 101 includes a lower hearth 1011 and an upper hearth 1012, the lower hearth 1011 is in communication with the upper hearth 1012 and is located below the upper hearth 1012, the outlet of the slag burning chamber 102 is in communication with the lower hearth 1011, the boiler body 1 has a recess 103, the recess 103 surrounds the boiler body 1 along the central axis of the boiler body 1 for one turn, and the recess 103 is located at the communication position of the lower hearth 1011 and the upper hearth 1012.

[0046] As Figure 1 and Figure 2As shown, the front side, rear side, left side and right side of the lower furnace 1011 are provided with slag burning chambers 102, and the temperature in the lower furnace 1011 is 1400-1700℃. The flames and unburned coal powder discharged from the four slag burning chambers rotate and mix in the lower furnace and are combusted, so that the coal powder is substantially combusted in the lower furnace, and the heat generated by the combustion of the coal powder moves upward and is fully exchanged in the upper furnace.

[0047] The recess 103 is annular on the boiler body 1, and forms a contraction opening at the position where the lower furnace 1011 and the upper furnace 1012 are communicated. The flame, unburned coal particles and ash produced by combustion near the wall surface of the boiler body 1 are pressed by the recess in the lower furnace or pushed to the center of the furnace, so that the situation of slagging and fouling of the heating surface in the upper furnace is greatly reduced, and the water-cooled wall in the upper furnace is also avoided from being impacted by the flame.

[0048] The height of the upper furnace 1012 is higher than that of the lower furnace 1011, and the top of the upper furnace 1012 is provided with a plurality of levels of screen heating surfaces. The higher space of the upper furnace 1012 enables the heat generated by the combustion of the coal powder to be reduced to 800-900℃ when moving to the bottom of the screen heating surface, so that the screen heating surface is avoided from being slagged and fouled, and the flue gas passage is also avoided from being blocked.

[0049] It can be understood that, in other embodiments, the boiler body can also not have the recess, and the boiler body is a straight cylinder extending in the up-down direction.

[0050] In some embodiments, the tangentially fired liquid slagging boiler of the embodiment of the present application further comprises a slag catching device 3 connected to the boiler body 1 and arranged at the outlet of the slag burning chamber 102.

[0051] The slag catching device plays a role of catching the flame and coal powder about to be discharged from the slag burning chamber, so that more impurities of the coal powder remain in the slag burning chamber and are then collected by the liquid slag hopper.

[0052] In some embodiments, the slag catching device 3 comprises a slag catching pipe bundle, which comprises a plurality of parallel and spaced slag catching pipes, and the slag catching pipes contain cooling medium inside.

[0053] As shown in FIG. 2, the slag catching pipe bundle is arranged at the outlet of the slag burning chamber 102. Figure 1As shown, the slag catching pipe bundle is arranged at the outlet of the slag burning chamber and extends in the up-down direction, and the size of the interval space between adjacent slag catching pipes is preferably 1-3 times the pipe diameter of the slag catching pipe. The slag catching pipe is internally provided with circulating cooling water to maintain the temperature of the outer circumferential surface of the slag catching pipe, and the flame and coal powder in the slag burning chamber pass through the gaps between the plurality of slag catching pipes into the lower hearth. When the flame and coal powder pass through the slag catching pipe bundle, on the one hand, the slag catching pipe itself plays a role in intercepting impurities, and on the other hand, the outer circumferential surface of the slag catching pipe also plays a role in adsorption due to the low temperature, so that the impurities are attached to the slag catching pipe and slide along the extension direction of the slag catching pipe.

[0054] It can be understood that the structure of the slag catching device is not limited to including a plurality of parallel and spaced slag catching pipes. In other embodiments, a plurality of slag catching pipes are arranged in the form of the side line of a polygon at the outlet of the slag burning chamber. For example, the slag catching device includes three slag catching pipes arranged in a triangle, and the center line of the triangle coincides with the center line of the outlet of the slag burning chamber.

[0055] In some embodiments, the extension direction of the slag catching pipe bundle has an inclination angle with the up-down direction, and the inclination angle is less than 30°.

[0056] As shown in Figure 1 the slag catching pipe bundle at the outlet of the left slag burning chamber 102 extends from top to bottom and is inclined to the right, the slag catching pipe bundle at the outlet of the right slag burning chamber 102 extends from top to bottom and is inclined to the left, and similarly, the slag catching pipe bundle at the outlet of the front slag burning chamber 102 extends from top to bottom and is inclined backward, and the slag catching pipe bundle at the outlet of the rear slag burning chamber 102 extends from top to bottom and is inclined forward.

[0057] The inclination angle less than 30° enables the impurities attached to the slag catching pipe to slide by itself, and at the same time, ensures the contact area of the slag catching pipe bundle with the flame and coal powder, thereby ensuring the effect of trapping impurities.

[0058] In some embodiments, the tangentially fired liquid slag discharge boiler of the present embodiment further comprises a liquid slag bucket 4 and a water tank 5. The liquid slag bucket 4 has an inlet and an outlet, and the liquid slag bucket 4 is connected to the boiler body 1 so that the slag burning chamber 102 communicates with the inlet of the liquid slag bucket 4. One end of the slag catching device 3 is arranged on the inner circumferential surface of the liquid slag bucket 4, and the outlet of the liquid slag bucket 4 communicates with the water tank 5.

[0059] As shown in Figure 1 and Figure 2 each slag burning chamber 102 is respectively provided with a liquid slag bucket 4, the cross-sectional area of the liquid slag bucket 4 gradually decreases in the direction from top to bottom, the lower end of the slag catching device 3 is arranged on the inner circumferential surface of the liquid slag bucket 4, the outlet of the liquid slag bucket 4 is arranged at the bottom of the liquid slag bucket 4, and the outlet of the liquid slag bucket 4 communicates with the water tank 5 through a slag well 13.

[0060] The coal combustion flame discharged from the slag combustion chamber will produce liquid ash slag containing alkali metal in a molten state during combustion, which is collected by the liquid slag bucket and discharged into the water tank through the slag well. The impurities captured by the slag catcher will also fall into the slag bucket and be discharged into the water tank. The water tank contains granulation water, and the liquid ash slag and alkali metal melt are rapidly cooled to form small solid slag particles for subsequent processing.

[0061] In some embodiments, the tangentially fired liquid slag discharge boiler of the present embodiment further comprises a slag conveyor 6 connected to the water tank 5 to remove the slag particles in the water tank 5.

[0062] As shown in Figure 1 The slag conveyor 6 extends horizontally and is connected to the water tank 5 corresponding to the two slag combustion chambers 102 in the extension direction. Thus, the slag particles in the water tank 5 corresponding to the two slag combustion chambers 102 are removed by the slag conveyor 6 for unified processing.

[0063] It can be understood that in other embodiments, the tangentially fired liquid slag discharge boiler can also not be provided with a slag conveyor, and the slag particles in the water tank can be removed by manual or other means.

[0064] In some embodiments, the bottom of the boiler body 1 has a dry slag bucket 104, and the internal space of the dry slag bucket 104 is in communication with the hearth 101.

[0065] As shown in Figure 1 The bottom of the lower hearth 1011 is in communication with the internal space of the dry slag bucket 104, the cross section of the dry slag bucket 104 gradually decreases from top to bottom, and the bottom of the dry slag bucket 104 is provided with an outlet, and the outlet of the dry slag bucket 104 is arranged towards the slag conveyor 6.

[0066] The unburned coal powder discharged from the slag combustion chamber into the lower hearth will produce some slag particles and ash particles condensed into solid particles during combustion. The solid particle slag and ash particles are collected by the dry slag bucket and discharged onto the slag conveyor, so that the solid particle slag and ash particles are uniformly transported and processed with the slag particles removed from the water tank.

[0067] In some embodiments, the tangentially fired liquid slag discharge boiler of the present embodiment further comprises a soot blower 7 and / or a combustion air device 8. The boiler body 1 comprises a membrane water wall surrounding the hearth 101, and the membrane water wall is provided with a first opening and / or a second opening in communication with the hearth 101.

[0068] The soot blower 7 comprises a steam nozzle, a steam pipe and an extension mechanism. The extension mechanism is arranged on the outer wall surface of the membrane water wall, and the extension mechanism is provided with the steam nozzle. The extension mechanism drives the steam nozzle to enter or exit the hearth 101 through the first opening, and the steam nozzle is in communication with the steam pipe.

[0069] The burnout air device 8 is arranged on the outer wall surface of the membrane water wall, and the air outlet of the burnout air device 8 is arranged in the second opening.

[0070] As shown in Figure 1 The membrane water wall surrounds one circle in the up-down direction to form the upper furnace 1012 to exchange heat with the heat generated by burning coal, and the membrane water wall is provided with the first opening and the second opening which communicate with the furnace 101.

[0071] As shown in Figure 1 The membrane water wall surrounds one circle in the up-down direction to form the upper furnace 1012 to exchange heat with the heat generated by burning coal, and the membrane water wall is provided with the first opening and the second opening which communicate with the furnace 101.

[0072] As shown in Figure 1 The membrane water wall surrounds one circle in the up-down direction to form the upper furnace 1012 to exchange heat with the heat generated by burning coal, and the membrane water wall is provided with the first opening and the second opening which communicate with the furnace 101.

[0073] It can be understood that, in other embodiments, the tangentially fired liquid slagging boiler can also not have the soot blower and the burnout air device, or not have the soot blower or not have the burnout air device.

[0074] In some embodiments, the tangentially fired liquid slagging boiler of the embodiment of the present application further comprises a screen heating surface 9, the screen heating surface 9 is connected with the boiler body 1, the boiler body 1 further comprises a flue gas passage 105, the top of the furnace 101 communicates with the flue gas passage 105, and the screen heating surface 9 is arranged in the top of the furnace 101 and / or the flue gas passage 105.

[0075] As shown in Figure 1As shown, the screen-type heating surface 9 includes a front screen superheater 901, a rear screen superheater 902, a high-temperature superheater 903, a high-temperature reheater 904 and a low-temperature reheater 905. The front screen superheater 901, the rear screen superheater 902, the high-temperature superheater 903 and the high-temperature reheater 904 are arranged on the top of the upper furnace 1012 and arranged in sequence from left to right. The low-temperature reheater 905 is arranged in the flue gas channel 105.

[0076] The boiler body 1 includes a front wall and a rear wall. The upper furnace 1012 is provided with a first tube-plate heat exchange surface close to the front wall and a second tube-plate heat exchange surface close to the rear wall. The front screen superheater 901 is suspended at the top of the upper furnace 1012 and close to the first tube-plate heat exchange surface. The rear screen superheater 902 is suspended at the top of the upper furnace 1012 and close to the second tube-plate heat exchange surface. The high-temperature superheater 903 is used to continue heating the superheated steam that has not reached the rated temperature after being heated in sequence by the furnace 101, the front screen superheater 901 and the rear screen superheater 902 to the rated main steam temperature. The high-temperature reheater 904 is used to heat the turbine exhaust steam heated by the low-temperature reheater 905 to the rated reheat steam temperature.

[0077] In some embodiments, the liquid slag discharge boiler with a tangential combustion method in an embodiment of the present invention also includes an economizer 11 and an air preheater 12. The economizer 11 and the air preheater 12 are respectively connected to the boiler body 1, and at least parts of the economizer 11 and the air preheater 12 are located in the flue gas channel 105.

[0078] like Figure 1 As shown, the economizer 11 is located upstream of the air preheater 12 in the flue gas channel 105. The economizer and the air preheater are both used to recover the waste heat of the flue gas discharged from the flue gas channel 105.

[0079] In the description of the present invention, it should be understood that the terms "up", "down", "left", "right", "horizontal", "top", "bottom", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 on the present invention.

[0080] Furthermore, the terms "first" and "second" are used solely to distinguish components or directions and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features being referred to. Therefore, features defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0081] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connecting", "fixed", "fixedly connected", "connection", "fixedly connected", "connected", "fixed", and the like should be construed broadly, for example, can be fixed connection, can be detachable connection, or integral; can be mechanical connection, can be electrical connection or communication with each other; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0082] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the first feature is higher than the second feature in horizontal height. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0083] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the specification and the features of different embodiments or examples without contradiction.

[0084] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and cannot be construed as limiting the present application, and the changes, modifications, replacements and variations of the above embodiments made by those skilled in the art are within the scope of the present application.

Claims

1. A tangentially fired liquid slag removal boiler, characterized in that: include: A boiler body (1), wherein a furnace (101) and a slag combustion chamber (102) are provided in the boiler body (1), the slag combustion chamber (102) having an inlet and an outlet, the outlet of the slag combustion chamber (102) being in communication with the furnace (101), the slag combustion chamber (102) being multiple, the multiple slag combustion chambers (102) surrounding the outer periphery of the furnace (101), and the center line of the outlet of each slag combustion chamber (102) being a tangent to the same imaginary tangent circle; A burner (2), the burner (2) being connected to the boiler body (1) so that the outlet of the burner (2) is in communication with the inlet of the slag combustion chamber (102), the burner (2) being a cyclone burner, the coal being ignited and burned in the cyclone burner (2) and the slag combustion chamber (102), and most of the ash components being removed under the capture action of the slag combustion chamber (102); A soot blower (7) and an overburning air device (8), wherein the boiler body (1) comprises a membrane water-cooled wall, the membrane water-cooled wall surrounds the furnace (101), and the membrane water-cooled wall is provided with a first opening and / or a second opening connected to the furnace (101); the soot blower (7) comprises a steam nozzle, a steam pipe and a telescopic mechanism, the telescopic mechanism is provided on the outer wall surface of the membrane water-cooled wall, the telescopic mechanism is provided with the steam nozzle, and the telescopic mechanism drives the steam nozzle to enter or exit the furnace (101) through the first opening, and the steam nozzle is connected to the steam pipe; the overburning air device (8) is provided on the outer wall surface of the membrane water-cooled wall, and the air outlet of the overburning air device (8) is provided in the second opening; After the coal is ignited by the burner, it is first ignited and burned in the slag combustion chamber in a liquid slag film environment, and the alkali metal is solidified and captured through physical and chemical reactions, so that most of the ash components are intercepted outside the furnace in the form of liquid slag. The coal flame with a low ash content discharged by the burner needs to pass through the slag combustion chamber along the extension direction of the slag combustion chamber before it can enter the furnace for tangential combustion and burn out in the furnace. The temperature of the outlet of the slag combustion chamber (102) is 1500°C to 1600°C. The furnace (101) comprises a lower furnace (1011) and an upper furnace (1012), wherein the lower furnace (1011) is connected to the upper furnace (1012) and is located below the upper furnace (1012), and the outlet of the slag combustion chamber (102) is connected to the lower furnace (1011), the height of the upper furnace (1012) is higher than that of the lower furnace (1011), and a multi-stage screen-type heating surface is provided on the top of the upper furnace (1012). The higher space of the upper furnace (1012) enables the heat generated by the combustion of pulverized coal to be reduced to 800°C-900°C when it moves to the bottom of the screen-type heating surface.

2. The tangentially fired liquid slag removal boiler according to claim 1, characterized in that: The furnace (101) extends in an up-down direction, and the furnace (101) is provided with the slag combustion chamber (102) extending in the first direction on both sides thereof, the first direction being orthogonal to the up-down direction, and the furnace (101) is provided with the slag combustion chamber (102) extending in the second direction on both sides thereof, the second direction being orthogonal to the first direction and the up-down direction, the outlet and inlet of the slag combustion chamber (102) are located on the same straight line, and the opening direction of the outlet of the slag combustion chamber (102) is opposite to the opening direction of the inlet.

3. The tangentially fired liquid slag removal boiler according to claim 2, characterized in that: The boiler body (1) has a recessed portion (103), which surrounds the boiler body (1) around the central axis of the boiler body (1) and is located at a communication position between the lower furnace (1011) and the upper furnace (1012).

4. The tangentially fired liquid slag removal boiler according to claim 1, characterized in that: It also includes a slag catching device (3), which is connected to the boiler body (1) and is arranged at the outlet of the slag combustion chamber (102).

5. The tangentially fired liquid slag removal boiler according to claim 4, characterized in that: The slag catching device (3) comprises a slag catching tube bundle, wherein the slag catching tube bundle comprises a plurality of slag catching tubes arranged in parallel and at intervals, wherein the slag catching tubes contain a cooling medium.

6. The tangentially fired liquid slag removal boiler according to claim 5, characterized in that: An inclination angle is formed between the extending direction of the slag catching tube bundle and the up-down direction, and the inclination angle is less than 30°.

7. The tangentially fired liquid slag removal boiler according to claim 4, characterized in that: The boiler also includes a liquid slag hopper (4) and a water tank (5). The liquid slag hopper (4) has an inlet and an outlet. The liquid slag hopper (4) is connected to the boiler body (1) so that the slag combustion chamber (102) is connected to the inlet of the liquid slag hopper (4). One end of the slag catching device (3) is arranged on the inner peripheral surface of the liquid slag hopper (4), and the outlet of the liquid slag hopper (4) is connected to the water tank (5).

8. The tangentially fired liquid slag removal boiler according to claim 7, characterized in that: It also includes a slag scooping machine (6), which is connected to the water tank (5) to scoop out slag particles in the water tank (5).

9. The tangentially fired liquid slag removal boiler according to claim 1, characterized in that: The bottom of the boiler body (1) is provided with a dry slag hopper (104), and the internal space of the dry slag hopper (104) is communicated with the furnace (101).

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