Test apparatus and method for high basicity coal pollutant emission control

Abstract

This invention discloses an experimental apparatus and method for controlling pollutant emissions from high-alkali coal. The experimental apparatus includes: a boiler comprising a furnace and a flue, the interior of which is divided into an ignition zone, a main combustion zone, a reburning zone, and a burnout zone along its height; a fuel pretreatment device having a first outlet, a second outlet, and a first inlet, the first outlet being connected to the main combustion zone; a pre-combustion device including a first fan and a pre-combustion chamber, the inlet of the first fan being adapted to be connected to outside air, the outlet of the first fan being connected to the pre-combustion chamber, the second outlet being connected to the pre-combustion chamber, and the outlet of the pre-combustion chamber being connected to the reburning zone; a primary fan, the outlet of which is connected to the first inlet via a first air inlet pipe; and a secondary fan, the outlet of which is connected to the main combustion zone via a second air inlet pipe. The experimental apparatus for controlling pollutant emissions from high-alkali coal according to this invention effectively improves the combustion environment inside the furnace, achieving low-NOx and high-efficiency combustion.

Description

Technical Field

[0001] This invention relates to the field of fuel combustion testing technology, and in particular to a testing apparatus and method for controlling pollutant emissions from high-alkali coal. Background Technology

[0002] Currently, coal-fired boilers mainly employ staged air combustion and deep staged air combustion to reduce NOx emission concentrations within the furnace. Specifically, in the NOx reduction zone space between the main combustion zone and the burnout zone, the oxygen concentration rapidly decreases to below 5% or even close to zero. The resulting strong reducing atmosphere reduces the NOx generated in the main combustion zone into nitrogen, lowering the NOx concentration at the reduction zone outlet to a low level. However, because a large amount of unburned reducing gaseous nitrogen-containing intermediates and incompletely released coke nitrogen remain at the reduction zone outlet, the combustion atmosphere transitions from an oxygen-deficient reducing atmosphere to an oxygen-rich oxidizing atmosphere as burnout air is injected. These residual nitrogen compounds are oxidized again under the oxidizing atmosphere of the burnout zone, regenerating NOx, resulting in a significant increase in the final NOx emission concentration at the burnout zone outlet. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention provides an experimental device for controlling pollutant emissions from high-alkali coal. This device can effectively improve the combustion environment inside the furnace, achieve low-NOx and high-efficiency combustion, reduce the content of nitrogen oxides in flue gas, and reduce pollutant emissions.

[0004] This invention also proposes a method for controlling the emission of pollutants from high-alkali coal.

[0005] According to a first aspect of the present invention, a test apparatus for controlling pollutant emissions from high-alkali coal includes: a boiler comprising a furnace and a flue, wherein the interior of the furnace is divided into an ignition zone, a main combustion zone, a reburning zone, and a burnout zone from bottom to top along its height, and the inlet end of the flue is connected to the outlet end of the burnout zone; a fuel pretreatment device for grinding high-alkali coal fuel into pulverized coal, the fuel pretreatment device having a first outlet, a second outlet, and a first inlet, the first outlet being connected to the main combustion zone and used to supply the pulverized coal to the main combustion zone; and a pre-combustion device comprising: A first blower and a pre-combustion chamber are provided. The inlet of the first blower is adapted to be connected to the outside air, and the outlet of the first blower is connected to the pre-combustion chamber to provide combustion air to the pre-combustion chamber. The second outlet is connected to the pre-combustion chamber to provide pulverized coal to the pre-combustion chamber. The air outlet of the pre-combustion chamber is connected to the re-combustion zone. A primary air blower is provided, with its outlet connected to the first inlet through a first air inlet pipe to provide primary air to the fuel pretreatment device. A secondary air blower is provided, with its outlet connected to the main combustion zone through a second air inlet pipe to provide secondary air to the main combustion zone.

[0006] The experimental apparatus for controlling pollutant emissions from high-alkali coal according to the present invention, by setting up a fuel pretreatment device and a pre-combustion device, can further and effectively improve the combustion environment inside the furnace, achieve low-NOx and high-efficiency combustion, thereby reducing the content of nitrogen oxides in flue gas and reducing pollutant emissions, thus improving the overall environmental friendliness and operational reliability of the apparatus.

[0007] According to some embodiments of the present invention, the pre-combustion device further includes a mixing chamber connected between the first fan and the pre-combustion chamber, and the test device further includes a first branch pipe and a second fan, wherein the mixing chamber is connected to the flue through the first branch pipe, and the second fan is connected in series on the first branch pipe.

[0008] According to some embodiments of the present invention, the test apparatus further includes an SCR denitrification device, which is arranged inside the flue.

[0009] According to some embodiments of the present invention, the test apparatus further includes: an air preheater, which is arranged in the flue and connected to the outlet end of the SCR denitrification device, and the air preheater is connected in series on the first air inlet pipe and the second air inlet pipe for heating the primary air and the secondary air.

[0010] According to some embodiments of the present invention, the test apparatus further includes: a dust removal device, a desulfurization device, a third fan, and a chimney. The dust removal device is connected to the flue and is arranged downstream of the air preheater along the flue gas flow direction. The desulfurization device is connected to the outlet end of the dust removal device. The chimney is connected to the outlet end of the desulfurization device. The third fan is connected between the desulfurization device and the chimney.

[0011] According to some embodiments of the present invention, the desulfurization device is a semi-dry desulfurization device.

[0012] According to some embodiments of the present invention, the furnace further includes: a first sidewall and a second sidewall arranged opposite to each other in a front-rear direction; the test device further includes: a swirl burner, the swirl burner being arranged on the sidewall of the main combustion zone and connected to the first outlet through a first air outlet pipe, the number of the swirl burners being multiple, the multiple swirl burners being spaced apart in a vertical direction and arranged opposite to each other on the first sidewall and the second sidewall; a first direct current burner, the first direct current burner being arranged on the sidewall of the main combustion zone and connected to the first outlet through a second air outlet pipe, and arranged below the swirl burner, the number of the first direct current burners being multiple, the multiple first direct current burners being spaced apart in a vertical direction and arranged opposite to each other on the first sidewall and the second sidewall; a control valve, the control valve being connected to the first air outlet pipe and / or the second air outlet pipe, for controlling the fuel pretreatment device to be switchably connected to the first direct current burner and / or connected to the swirl burner.

[0013] According to some embodiments of the present invention, the test apparatus further includes: a second DC burner, the second DC burner being arranged on the side wall of the reburning zone and connected to the air outlet of the pre-combustion chamber through a third air outlet pipe, the number of the second DC burners being multiple, the multiple second DC burners being arranged at intervals along the vertical direction and arranged opposite to each other on the first side wall and the second side wall.

[0014] According to a second aspect of the present invention, a method for controlling pollutant emissions from high-alkali coal combustion is used in a test apparatus for controlling pollutant emissions from high-alkali coal combustion according to a first aspect of the present invention. The method includes: heating the primary air to a first preset value, and conveying the heated primary air to the fuel pretreatment device to send a portion of the ground coal powder in the fuel pretreatment device into the main combustion zone, and another portion of the coal powder to the pre-combustion chamber; heating the secondary air to a second preset value, and directly conveying the heated secondary air to the main combustion zone; extracting high-temperature flue gas reaching a third preset value from the flue and outside air, mixing the high-temperature flue gas and the air, and conveying the mixture to the pre-combustion chamber to pre-combust the coal powder in the pre-combustion chamber to generate gaseous fuel; and conveying the gaseous fuel to the re-combustion zone.

[0015] According to the method for controlling pollutant emissions from high-alkali coal combustion of the present invention, by sending a portion of the ground coal powder in the fuel pretreatment device into the main combustion zone and another portion of the coal powder to the pre-combustion chamber for pre-combustion before being sent into the re-combustion zone, the content of nitrogen oxides in the flue gas generated by combustion in the furnace can be further reduced, thereby improving the environmental friendliness and operational reliability of the overall device.

[0016] According to some embodiments of the present invention, the method further includes: an SCR denitrification device performing denitrification treatment on the flue gas discharged from the combustion zone; the denitrified flue gas exchanging heat with primary air and secondary air; the heat-exchanged flue gas being dust-removed by a dust removal device; the dust-removed flue gas undergoing semi-dry desulfurization by a desulfurization device; and the desulfurized flue gas being discharged through a chimney.

[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] Figure 1 This is a schematic diagram of an experimental apparatus for controlling high-alkali coal pollutant emissions according to an embodiment of the present invention.

[0019] Figure label: 100. Test apparatus; 10. Boiler; 11. Furnace; 111. Ignition Zone; 112. Main Combustion Zone; 113. Reburning Zone; 114. Burnout Zone; 12. Flue; 20. Fuel pretreatment unit; 30. Pre-combustion device; 31. First blower; 32. Pre-combustion chamber; 33. Mixing chamber; 40. Primary air fan; 50. Secondary air fan; 61. First branch pipe; 62. Second fan; 71. SCR denitrification unit; 72. Air preheater; 73. Dust removal unit; 74. Desulfurization unit; 75. Third fan; 76. Chimney; 81. Swirl burner; 82. First DC burner; 83. Second DC burner. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below, examples of which are illustrated 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 intended to explain the present invention, and should not be construed as limiting the present invention.

[0021] The following is for reference. Figure 1 An experimental apparatus 100 for controlling high-alkali coal pollutant emissions according to an embodiment of the first aspect of the present invention is described.

[0022] like Figure 1 As shown, the experimental apparatus 100 for controlling high-alkali coal pollutant emissions according to a first aspect embodiment of the present invention includes: a boiler 10, a fuel pretreatment device 20, a pre-combustion device 30, a primary air fan 40, and a secondary air fan 50.

[0023] The boiler 10 includes a furnace 11 and a flue 12. The interior of the furnace 11 is divided into an ignition zone 111, a main combustion zone 112, a reburning zone 113 and a burnout zone 114 along its height direction from bottom to top. The inlet end of the flue 12 is connected to the outlet end of the burnout zone 114.

[0024] Specifically, the ignition zone 111 is located at the bottom of the furnace 11 and is mainly used to achieve initial ignition and stable combustion of the fuel, providing a stable ignition source for subsequent main combustion and ensuring reliable combustion start-up. The main combustion zone 112 is located above the ignition zone 111 and is the main area for fuel combustion and heat release. It burns under oxygen-deficient or staged air distribution conditions and suppresses NO3- in the fuel. x The main combustion zone 112 is located above the main combustion zone 112, where a reducing atmosphere is created by injecting reburning fuel, thus reducing the NO generated in the main combustion zone 112. x The area is reduced to N2, further reducing nitrogen oxide emissions; the burnout zone 114 is located at the top of the furnace 11, where burnout air needs to be introduced to provide sufficient oxygen for incompletely burned products, ensuring that combustibles are fully burned, improving combustion efficiency, and reducing the carbon content of fly ash.

[0025] The fuel pretreatment device 20 is used to grind high-alkali coal fuel into pulverized coal. The fuel pretreatment device 20 has a first outlet, a second outlet, and a first inlet. The first outlet is connected to the main combustion zone 112 and is used to supply pulverized coal to the main combustion zone 112. The pre-combustion device 30 includes a first blower 31 and a pre-combustion chamber 32. The inlet end of the first blower 31 is adapted to be connected to the outside air. The outlet end of the first blower 31 is connected to the pre-combustion chamber 32 and is used to supply combustion air to the pre-combustion chamber 32. The second outlet is connected to the pre-combustion chamber 32 and is used to supply pulverized coal to the pre-combustion chamber 32. The outlet of the pre-combustion chamber 32 is connected to the re-combustion zone 113. The outlet of the primary air blower 40 is connected to the first inlet through a first air inlet pipe and is used to supply primary air to the fuel pretreatment device 20. The outlet of the secondary air blower 50 is connected to the main combustion zone 112 through a second air inlet pipe and is used to supply secondary air to the main combustion zone 112.

[0026] Understandably, the fuel pretreatment device 20 is mainly used to grind high-alkali coal fuel into coal powder. Part of the ground coal powder is directly sent to the main combustion zone 112 for combustion through primary air, and part of it is sent to the pre-combustion chamber 32 through the second outlet of primary air for pre-combustion to generate incomplete combustion products. Then the incomplete combustion products are sent to the re-combustion zone 113 for combustion.

[0027] The pulverized coal entering the main combustion zone 112 is ground, which improves the combustion stability of the fuel, thereby preventing the formation of localized high-temperature zones and suppressing the formation of thermal NOx. Meanwhile, the fuel entering the recombustion zone 113 is gaseous fuel. Gaseous fuels burn more stably than pulverized coal, and because they are incomplete combustion products, when transported to the recombustion zone 113, they will react with the NOx generated in the main combustion zone 112. x A reduction reaction occurs, further enhancing air quality classification and further reducing NOx emissions.

[0028] It should be noted that the fuel pretreatment device 20 can also dynamically change the grinding degree of pulverized coal according to the fluctuation of the actual load of the boiler 10, so as to adapt to the combustion requirements under different loads, stabilize the combustion characteristics, and ensure that the boiler 10 maintains a high-efficiency combustion state in each load segment.

[0029] The experimental device 100 for controlling pollutant emissions from high-alkali coal according to the present invention, by setting up a fuel pretreatment device 20 and a pre-combustion device 30, can further effectively improve the combustion environment inside the furnace, achieve low-NOx and high-efficiency combustion, thereby reducing the content of nitrogen oxides in flue gas and reducing pollutant emissions, thus improving the overall environmental protection and operational reliability of the device.

[0030] According to some embodiments of the present invention, such as Figure 1As shown, the pre-combustion device 30 also includes a mixing chamber 33, which is connected between the first blower 31 and the pre-combustion chamber 32. The test device 100 also includes a first branch pipe 61 and a second blower 62. The mixing chamber 33 is connected to the flue 12 through the first branch pipe 61, and the second blower 62 is connected in series with the first branch pipe 61. Specifically, when the boiler 10 is working, the second blower 62 draws high-temperature flue gas from the flue 12 and delivers it to the mixing chamber 33. Then, in the mixing chamber 33, it mixes with the air from the first blower 31 and delivers it to the pre-combustion chamber 32, providing combustion-supporting gas and a large amount of heat for the pre-combustion in the pre-combustion chamber 32. This not only improves the stability of pulverized coal pre-combustion but also reduces the ignition energy consumption of the pre-combustion chamber 32. In addition, the extraction of high-temperature flue gas from the flue 12 can also reasonably control the overall temperature in the furnace 11 and adjust the air supply temperature of the pre-combustion device 30, thereby flexibly responding to the changing load requirements of the boiler 10. In addition, the mixing chamber 33 can reduce the temperature of the gas entering the furnace 11, thereby reducing the overall temperature of the entire furnace 11 and reducing the generation of thermal NOx.

[0031] It should be noted that the amount of flue gas extracted by the second fan 62 is controlled by the load of the boiler 10, etc.

[0032] According to some embodiments of the present invention, such as Figure 1 As shown, the test apparatus 100 also includes an SCR denitrification device 71, which is arranged inside the flue 12. The SCR denitrification device 71 is mainly used to denitrify the flue gas generated in the furnace 11, in order to further reduce the content of nitrogen oxides in the flue gas.

[0033] According to some embodiments of the present invention, such as Figure 1 As shown, the test apparatus 100 also includes an air preheater 72, which is arranged inside the flue 12 and connected to the outlet end of the SCR denitrification device 71. The air preheater 72 is connected in series with the first and second air inlet pipes to heat the primary and secondary air. It can be understood that the flue gas after denitrification by the SCR denitrification device 71 enters the air preheater 72 to heat the primary and secondary air, thus further improving the energy utilization rate of the flue gas.

[0034] According to some embodiments of the present invention, such as Figure 1As shown, the test apparatus 100 also includes: a dust removal device 73, a desulfurization device 74, a third fan 75, and a chimney 76. The dust removal device 73 is connected to the flue duct 12 and is arranged downstream of the air preheater 72 along the flue gas flow direction. The desulfurization device 74 is connected to the outlet end of the dust removal device 73, and the chimney 76 is connected to the outlet end of the desulfurization device 74. The third fan 75 is connected between the desulfurization device 74 and the chimney 76. It can be understood that after the flue gas is discharged from the air preheater 72, it passes through the dust removal device 73 and the desulfurization device 74 in sequence, and is then transported to the chimney 76 by the third fan 75 for discharge. The dust removal device 73 is mainly used to remove particulate matter from the flue gas, and the desulfurization device 74 is mainly used to remove sulfides from the flue gas.

[0035] In addition, in this embodiment, the desulfurization device 74 is arranged downstream of the dust removal device 73, which can remove most of the dust in the flue gas in advance, avoid dust covering the active sites of the desulfurizing agent, thereby improving the desulfurization efficiency and the utilization rate of the desulfurizing agent. At the same time, it can also reduce the accumulation of ash, blockage and wear inside the desulfurization device 74, thereby extending the service life of the equipment.

[0036] According to some embodiments of the present invention, the desulfurization device 74 is a semi-dry desulfurization device 74. That is, this embodiment achieves flue gas desulfurization through a semi-dry method. Specifically, semi-dry desulfurization involves atomizing and injecting an alkaline slurry (such as lime slurry) into the flue gas. Simultaneously, the gas and liquid phases react in contact, and the heat from the flue gas completely evaporates and dries the slurry, ultimately forming dry desulfurization ash and eliminating wastewater discharge. Since the final product of semi-dry desulfurization is a dry powder and there is no wastewater discharge, using semi-dry desulfurization allows the flue gas to meet ultra-low emission requirements.

[0037] According to some embodiments of the present invention, such as Figure 1 As shown, the furnace 11 further includes: a first sidewall and a second sidewall arranged opposite to each other in the front-rear direction. The test device 100 further includes: a swirl burner 81, a first direct-flow burner 82, and a control valve. The swirl burner 81 is arranged on the sidewall of the main combustion zone and is connected to the first outlet through a first air outlet pipe. There are multiple swirl burners 81, which are arranged at intervals in the vertical direction and opposite to each other on the first and second sidewalls. The first direct-flow burner 82 is arranged on the sidewall of the main combustion zone and is connected to the first outlet through a second air outlet pipe, and is arranged below the swirl burner 81. There are multiple first direct-flow burners 82, which are arranged at intervals in the vertical direction and opposite to each other on the first and second sidewalls. The control valve is connected to the first air outlet pipe and / or the second air outlet pipe and is used to control the fuel pretreatment device 20 to be switchably connected to the first direct-flow burner 82 and / or connected to the swirl burner 81.

[0038] It is understood that in this embodiment, the main combustion zone 112 can be injected and stably combusted solely by the first direct-flow burner 82, or solely by the swirl burner 81, or both by the first direct-flow burner 82 and the swirl burner 81. When only the first direct-flow burner 82 is used for injection and stable combustion, it is a counter-current combustion between the front and rear walls; when both the first direct-flow burner 82 and the swirl burner 81 are used for injection and stable combustion, it is a tangential combustion at the four corners.

[0039] That is, the control valve can be used to control the combustion mode of the main combustion zone 112, allowing the combustion mode to be switched according to fuel characteristics and operating conditions, thereby improving the adaptability of the boiler 10. In addition, the multi-layer burner configuration can also facilitate the adaptation to scenarios involving the blending of multiple fuels.

[0040] According to some embodiments of the present invention, such as Figure 1 As shown, the experimental apparatus 100 further includes a second DC burner 83, which is arranged on the side wall of the reburning zone 113 and connected to the air outlet of the pre-combustion chamber 32 via a third air outlet pipe. Multiple second DC burners 83 are arranged at intervals along the vertical direction and opposite to each other on the first and second side walls. The arrangement of multiple second DC burners 83 allows for the uniform injection of reburning fuel into the reburning zone 113, thereby enhancing the uniformity of the reducing atmosphere distribution and further improving denitrification efficiency and optimizing the furnace temperature field.

[0041] According to a second aspect of the present invention, a method for controlling pollutant emissions from high-alkali coal combustion is used in a test apparatus 100 for controlling pollutant emissions from high-alkali coal combustion according to a first aspect of the present invention. The method includes: heating primary air to a first preset value, and then conveying the heated primary air to a fuel pretreatment device 20 to send a portion of the ground coal powder in the fuel pretreatment device 20 into the main combustion zone 112, and another portion of the coal powder to a pre-combustion chamber 32; heating secondary air to a second preset value, and then directly conveying the heated secondary air to the main combustion zone 112; extracting high-temperature flue gas reaching a third preset value from the flue duct 12 and outside air, mixing the high-temperature flue gas and air, and then conveying the mixture to the pre-combustion chamber 32 to pre-combust the coal powder and generate gaseous fuel; and then conveying the gaseous fuel to a re-combustion zone 113.

[0042] Optionally, the first preset value is 250℃-300℃; the second preset value is 300℃-350℃; and the third preset value is 950℃-1000℃.

[0043] For example, when boiler 10 is running, primary air is first drawn by primary air fan 40 and preheated to 250°C-300°C in air preheater 72. The preheated primary air is then sent to fuel pretreatment device 20, where ground coal powder is fed into main combustion zone 112 for combustion. Secondary air is then drawn by secondary air fan 50 and preheated to 300°C-350°C in air preheater 72. The preheated secondary air is then directly sent into main combustion zone 112. 2. Internal combustion: The first fan 31 draws external air into the mixing box. Then, when the flue gas in the furnace 11 enters the flue 12, the second fan 62 draws the high-temperature flue gas in the flue 12, which reaches 950℃-1000℃, into the mixing box to mix with the external air. The mixed gas is then introduced into the pre-combustion chamber 32 to assist in the combustion of pulverized coal to generate gaseous fuel. The gaseous fuel is an incomplete combustion product. The incomplete combustion product is then sent to the re-combustion zone 113 for combustion.

[0044] According to the method for controlling pollutant emissions from high-alkali coal combustion of the present invention, by sending a portion of the ground coal powder in the fuel pretreatment device 20 into the main combustion zone 112, and another portion of the coal powder to the pre-combustion chamber 32 for pre-combustion and then to the re-combustion zone 113, the content of nitrogen oxides in the flue gas generated by combustion in the furnace can be further reduced, thereby improving the environmental friendliness and operational reliability of the overall device.

[0045] According to some embodiments of the present invention, the method further includes: the SCR denitrification device 71 performing denitrification treatment on the flue gas discharged from the combustion zone 114; the denitrified flue gas exchanging heat with primary air and secondary air; the heat-exchanged flue gas being dust-removed by the dust removal device 73; the dust-removed flue gas being semi-dry desulfurized by the desulfurization device 74; and the desulfurized flue gas being discharged through the chimney 76.

[0046] Specifically, after the flue gas is treated in the burnout zone 114, it enters the flue 12 and first undergoes denitrification treatment by the SCR denitrification device 71. Then, the heat of the flue gas is used to heat the primary air and secondary air to achieve high utilization of the flue gas heat. After heat exchange, the flue gas is then treated by the dust removal device 73 and the desulfurization device 74 in sequence before being discharged through the chimney 76.

[0047] It should be noted that the flue gas discharged from the combustion zone 114 has already suppressed some NOx formation due to the use of air staging and fuel staging. Therefore, when the SCR denitrification device 71 denitrifies the flue gas discharged from the combustion zone 114, its denitrification efficiency can reach more than 80%. At the same time, since the desulfurization device 74 uses semi-dry desulfurization, the desulfurization efficiency reaches more than 90%. This greatly improves the pollutant removal efficiency, thereby achieving ultra-low emissions of pollutants.

[0048] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" 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 this invention and 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 this invention.

[0049] 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 technical features indicated. 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.

[0050] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication 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.

[0051] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," 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 present 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0052] 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. An experimental device (100) for controlling pollutant emissions from high-alkali coal, characterized in that, include: Boiler (10), the boiler (10) includes: furnace (11) and flue (12), the interior of the furnace (11) is divided into an ignition zone (111), a main combustion zone (112), a reburning zone (113) and a burnout zone (114) from bottom to top along its height direction, and the inlet end of the flue (12) is connected to the outlet end of the burnout zone (114); A fuel pretreatment device (20) is used to grind high-alkali coal fuel into coal powder. The fuel pretreatment device (20) has a first outlet, a second outlet and a first inlet. The first outlet is connected to the main combustion zone (112) and is used to supply the coal powder to the main combustion zone (112). A pre-combustion device (30) includes: a first fan (31) and a pre-combustion chamber (32). The inlet end of the first fan (31) is adapted to be connected to the outside air. The outlet end of the first fan (31) is connected to the pre-combustion chamber (32) for providing combustion air to the pre-combustion chamber (32). The second outlet is connected to the pre-combustion chamber (32) for providing the pulverized coal to the pre-combustion chamber (32). The air outlet of the pre-combustion chamber (32) is connected to the re-combustion zone (113). A primary air fan (40) has its outlet connected to the first inlet via a first air inlet pipe, and is used to provide primary air to the fuel pretreatment device (20). A secondary air fan (50) is provided, the air outlet of which is connected to the main combustion zone (112) through a second air inlet pipe, for providing secondary air to the main combustion zone (112).

2. The experimental apparatus (100) for controlling pollutant emissions from high-alkali coal according to claim 1, characterized in that, The pre-combustion device (30) further includes a mixing chamber (33), which is connected between the first fan (31) and the pre-combustion chamber (32). The test device (100) further includes: a first branch pipe (61) and a second fan (62), wherein the mixing chamber (33) is connected to the flue (12) through the first branch pipe (61), and the second fan (62) is connected in series on the first branch pipe (61).

3. The experimental apparatus (100) for controlling high-alkali coal pollutant emissions according to claim 1, characterized in that, Also includes: SCR denitrification device (71), which is arranged in the flue (12).

4. The experimental apparatus (100) for controlling high-alkali coal pollutant emissions according to claim 3, characterized in that, Also includes: An air preheater (72) is arranged in the flue (12) and connected to the outlet end of the SCR denitrification device (71). The air preheater (72) is connected in series on the first air inlet pipe and the second air inlet pipe to heat the primary air and the secondary air.

5. The experimental apparatus (100) for controlling high-alkali coal pollutant emissions according to claim 4, characterized in that, Also includes: The system includes a dust removal device (73), a desulfurization device (74), a third fan (75), and a chimney (76). The dust removal device (73) is connected to the flue (12) and is arranged downstream of the air preheater (72) along the flue gas flow direction. The desulfurization device (74) is connected to the outlet end of the dust removal device (73). The chimney (76) is connected to the outlet end of the desulfurization device (74). The third fan (75) is connected between the desulfurization device (74) and the chimney (76).

6. The experimental apparatus (100) for controlling high-alkali coal pollutant emissions according to claim 5, characterized in that, The desulfurization device (74) is a semi-dry desulfurization device (74).

7. The experimental apparatus (100) for controlling pollutant emissions from high-alkali coal according to claim 1, characterized in that, The furnace (11) further includes: a first sidewall and a second sidewall arranged opposite each other in the front-rear direction, and the test device (100) further includes: A swirl burner (81) is arranged on the side wall of the main combustion zone and connected to the first outlet through a first air outlet pipe. There are multiple swirl burners (81), which are arranged at intervals along the vertical direction and opposite to each other on the first side wall and the second side wall. The first DC burner (82) is arranged on the side wall of the main combustion zone and connected to the first outlet through the second air outlet pipe. It is arranged below the swirl burner (81). There are multiple first DC burners (82). Multiple first DC burners (82) are arranged at intervals along the vertical direction and are arranged opposite to each other on the first side wall and the second side wall. A control valve, connected to the first air outlet pipe and / or the second air outlet pipe, is used to control the fuel pretreatment device (20) to be switchably connected to the first DC burner (82) and / or to the swirl burner (81).

8. The experimental apparatus (100) for controlling high-alkali coal pollutant emissions according to claim 7, characterized in that, It also includes: a second DC burner (83), which is arranged on the side wall of the reburning zone (113) and connected to the air outlet of the pre-combustion chamber (32) through a third air outlet pipe. There are multiple second DC burners (83), which are arranged at intervals along the vertical direction and are arranged opposite to each other on the first side wall and the second side wall.

9. A method for controlling pollutant emissions from the combustion of high-alkali coal, used in the experimental apparatus (100) for controlling pollutant emissions from the combustion of high-alkali coal according to any one of claims 1-8, characterized in that, The method includes: The primary air is heated to a first preset value, and the heated primary air is sent to the fuel pretreatment device (20) to send part of the pulverized coal ground in the fuel pretreatment device (20) into the main combustion zone (112), and the other part of the pulverized coal is sent to the pre-combustion chamber (32). The secondary air is heated to a second preset value, and the heated secondary air is directly delivered to the main combustion zone (112); High-temperature flue gas reaching the third preset value and outside air are extracted from the flue (12), and the high-temperature flue gas and the air are mixed and transported to the pre-combustion chamber (32) so that the pulverized coal is pre-combusted in the pre-combustion chamber (32) to generate gaseous fuel; The gaseous fuel is delivered to the reburning zone (113).

10. The method for controlling pollutant emissions from high-alkali coal combustion according to claim 9, characterized in that, The method further includes: The SCR denitrification device (71) performs denitrification treatment on the flue gas discharged from the combustion zone (114); The denitrified flue gas exchanges heat with primary and secondary air; The flue gas after heat exchange is dusted by a dust removal device (73); The flue gas after dust removal is desulfurized by a semi-dry desulfurization device (74), and the desulfurized flue gas is discharged through a chimney (76).

Images