Synergistic heating desulfurization and denitrification system and method for flue gas of heating furnace

Abstract

The invention discloses a heating furnace flue gas synergistic heating desulfurization and denitrification system and method.The system comprises an air-smoke desulfurization and denitrification mechanism, an air-smoke heat exchanger, an air-smoke denitrification structure and an air-smoke desulfurization structure, a first air-smoke heat absorption pipeline of the air-smoke heat exchanger is connected to the upstream of the air-smoke denitrification structure, and a second air-smoke heat absorption pipeline of the air-smoke heat exchanger is connected to the downstream of the air-smoke denitrification structure; a first air-smoke heat release pipeline of the air-smoke heat exchanger is connected to the downstream of the air-smoke denitration structure; the soot desulfurization and denitrification mechanism comprises a soot heat exchanger, a soot denitrification structure and a soot desulfurization structure, a first soot heat absorption pipeline of the soot heat exchanger is connected to the upstream of the soot denitrification structure, and a first soot heat release pipeline of the soot heat exchanger is connected to the downstream of the soot denitrification structure; a second soot heat absorption pipeline of the air-coal heat exchanger is connected to the upstream of the soot heat exchanger, and a second air-smoke heat release pipeline of the air-coal heat exchanger is connected to the downstream of the air-smoke heat exchanger. According to the invention, the heat of the empty smoke and the soot smoke can be fully utilized, and the temperature of the soot smoke is balanced by utilizing the empty smoke, so that the energy consumption is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas treatment, and in particular to a system and method for coordinated heating, desulfurization and denitrification of flue gas from a heating furnace. Background Art

[0002] At present, the desulfurization and denitrification processes used in steel rolling heating furnaces in the domestic steel industry are mainly divided into dry desulfurization and SCR denitrification. Among them, dry desulfurization includes calcium-based fixed bed dry desulfurization, SDS dry desulfurization and calcium-based high-efficiency active dry desulfurization. Denitrification uses hot air furnace heating and catalyst denitrification.

[0003] The flue gas of the heating furnace is divided into coal smoke flue gas and air smoke flue gas. In the prior art, the coal smoke flue gas and air smoke flue gas of the heating furnace are generally treated and discharged separately. Among them, the process of dry desulfurization and denitrification is as follows: the flue gas drawn from the coal smoke system or air smoke system of the heating furnace enters the dry desulfurization system. The desulfurization injection point is selected on the flue before the desulfurization reactor. The SO2 in the flue gas in the reactor reacts with the dry desulfurizer to be removed. The flue gas after desulfurization enters the bag filter. The solid products generated by desulfurization and the smoke dust in the flue gas are efficiently captured by the bag filter. The flue gas after desulfurization and dust removal is heated through the primary heat exchanger and the secondary heat exchanger and then enters the SCR denitrification system. The flue gas is fully mixed with the ammonia generated by the ammonia evaporator at the inlet of the SCR reactor through the ammonia spray grid. The NOx in the flue gas undergoes a reduction reaction under the action of the catalyst and is converted into nitrogen and water, thereby achieving the purpose of removing NOx. The purified flue gas is discharged through the chimney by the induced draft fan. Summary of the invention

[0004] Although the prior art also adopts a combination of heat exchanger and hot blast furnace to increase temperature and denitrify in combination with dry desulfurization to jointly treat the coal smoke and air smoke of the heating furnace, the inventors of the present invention found that the prior art still has the following technical problems when jointly treating the coal smoke and air smoke of the heating furnace: 1. It is impossible to balance the desulfurization and denitrification temperatures of the coal smoke and air smoke; 2. It is impossible to fully utilize the temperature of the flue gas itself, resulting in energy waste; 3. The hot blast furnace needs to provide a large amount of supplementary hot flue gas, and it is also necessary to remove SO2 in the supplementary hot flue gas; 4. It is unable to adapt to the working condition where the temperature of the air smoke in the oriented silicon steel heating furnace is too high.

[0005] The purpose of the present invention is to provide a system and method for coordinated heating desulfurization and denitrification of flue gas from a heating furnace, so as to solve the technical problems that the desulfurization and denitrification temperatures of the coal smoke and air smoke from the heating furnace cannot be reduced and the temperature of the flue gas itself cannot be fully utilized, resulting in energy waste.

[0006] The above-mentioned purpose of the present invention can be achieved by adopting the following technical solutions:

[0007] The present invention provides a heating furnace flue gas coordinated heating desulfurization and denitrification system, comprising: an air smoke desulfurization and denitrification mechanism, comprising an air smoke heat exchanger, an air smoke denitrification structure and an air smoke desulfurization structure, the air smoke heat exchanger having a first air smoke heat absorption pipeline and a first air smoke heat release pipeline capable of heat exchange, the first air smoke heat absorption pipeline is connected to the upstream of the air smoke denitrification structure, and the first air smoke heat release pipeline is connected to the downstream of the air smoke denitrification structure; a coal smoke desulfurization and denitrification mechanism, comprising a coal smoke heat exchanger, a coal smoke denitrification structure and a coal smoke desulfurization structure, the coal smoke heat exchanger having a first coal smoke heat absorption pipeline and a first coal smoke heat release pipeline capable of heat exchange, The first coal smoke heat absorption pipeline is connected to the upstream of the coal smoke denitrification structure, and the first coal smoke heat release pipeline is connected to the downstream of the coal smoke denitrification structure; the air-coal heat exchanger has a second coal smoke heat absorption pipeline and a second air-smoke heat release pipeline that can perform heat exchange, the second coal smoke heat absorption pipeline is connected to the upstream of the coal smoke heat exchanger, and the second air-smoke heat release pipeline is connected to the downstream of the air-smoke heat exchanger, the air-smoke desulfurization structure is connected to the downstream of the second air-smoke heat release pipeline or the upstream of the first air-smoke heat absorption pipeline, and the coal smoke desulfurization structure is connected to the upstream of the second coal smoke heat absorption pipeline or the downstream of the first coal smoke heat release pipeline.

[0008] In an embodiment of the present invention, the heating furnace flue gas coordinated heating desulfurization and denitrification system also includes a heat supplement mechanism, which includes a coal smoke heat supplement structure and an air smoke heat supplement structure. The coal smoke heat supplement structure is connected to the upstream of the coal smoke denitrification structure and can supplement heat for the air smoke before denitrification. The air smoke heat supplement structure is connected to the upstream of the air smoke denitrification structure and can supplement heat for the air smoke before denitrification.

[0009] In an embodiment of the present invention, the heat supplement mechanism also includes a hot blast furnace, which is used to provide heat supplement flue gas; the coal smoke heat supplement structure has a coal smoke heat supplement pipeline capable of heat exchange and a first heat supplement flue gas heat release pipeline, and the coal smoke heat supplement pipeline is connected between the first coal smoke heat absorption pipeline and the coal smoke denitrification structure; the air smoke heat supplement structure is provided with a mixed heat exchange pipeline, and the mixed heat exchange pipeline is connected between the first air smoke heat absorption pipeline and the air smoke denitrification structure; the hot blast furnace, the first heat supplement flue gas heat release pipeline and the mixed heat exchange pipeline are connected in sequence along the conveying direction of the heat supplement flue gas.

[0010] In the embodiment of the present invention, the air-smoke desulfurization structure and the coal smoke desulfurization structure are both dry desulfurization structures, and the air-smoke denitrification structure and the coal smoke denitrification structure are both SCR denitrification structures.

[0011] In an embodiment of the present invention, the air smoke desulfurization and denitrification mechanism is connected upstream to the air smoke system of the oriented silicon steel heating furnace; the coal smoke desulfurization and denitrification mechanism is connected upstream to the coal smoke system of the oriented silicon steel heating furnace.

[0012] In an embodiment of the present invention, the air smoke desulfurization and denitrification mechanism also includes an air smoke dust removal structure, which is connected to the downstream of the air smoke desulfurization structure; the coal smoke desulfurization and denitrification mechanism also includes a coal smoke dust removal structure, which is connected to the downstream of the coal smoke desulfurization structure.

[0013] In the implementation manner of the present invention, an air smoke induced draft fan is connected downstream of the air smoke desulfurization and denitrification mechanism; and a coal smoke induced draft fan is connected downstream of the coal smoke desulfurization and denitrification mechanism.

[0014] The present invention also provides a method for coordinated heating desulfurization and denitrification of flue gas from a heating furnace, which adopts the above-mentioned coordinated heating desulfurization and denitrification system for flue gas from a heating furnace; the method comprises the following steps: performing heat exchange between the first air smoke before denitrification and the second air smoke after denitrification, so that the first air smoke is heated to obtain the third air smoke, and the second air smoke is cooled to obtain the fourth air smoke; performing heat exchange between the first coal smoke before denitrification and the fourth air smoke, so that the first coal smoke is heated to obtain the second coal smoke, and the fourth air smoke is cooled to obtain the fifth air smoke; the second coal smoke is heated to obtain the denitrification gas; the denitrification gas is heated to obtain the third coal smoke, and the denitrification gas is cooled to obtain the fourth coal smoke; the denitrification gas is heated to obtain the fifth coal smoke; the denitrification gas is heated to obtain the fifth coal smoke. The third coal smoke gas after heat exchange is carried out to heat the second coal smoke gas to obtain the fourth coal smoke gas, and the third coal smoke gas is cooled to obtain the fifth coal smoke gas; wherein, the first air smoke gas is the air smoke gas drawn out from the air smoke system, and the fifth air smoke gas is desulfurized to obtain the sixth air smoke gas; or the air smoke gas drawn out from the air smoke system is desulfurized to obtain the first air smoke gas; wherein, the first coal smoke gas is the coal smoke gas drawn out from the coal smoke system, and the fifth coal smoke gas is desulfurized to obtain the sixth coal smoke gas; or the coal smoke gas drawn out from the coal smoke system is desulfurized to obtain the first coal smoke gas.

[0015] In an embodiment of the present invention, the method further includes the following steps: performing heat exchange on the fourth coal smoke and the first supplementary heat flue gas, so that the fourth coal smoke is heated up to obtain a seventh coal smoke, and the first supplementary heat flue gas is cooled down to obtain a second supplementary heat flue gas; and denitrifying the seventh coal smoke to obtain the third coal smoke.

[0016] In an embodiment of the present invention, the method further includes the following steps: exchanging heat between the third air flue gas and the second heat supplementary flue gas to heat the third air flue gas to obtain the seventh air flue gas; and denitrifying the seventh air flue gas to obtain the second air flue gas.

[0017] In an embodiment of the present invention, the seventh coal smoke flue gas and the seventh air smoke flue gas have the same temperature.

[0018] In an embodiment of the present invention, the method also includes the following steps: dust removal on the sixth air flue gas after denitrification and desulfurization; or dust removal on the first air flue gas after desulfurization before heat exchange between the first air flue gas and the second air flue gas; dust removal on the sixth coal smoke gas after denitrification and desulfurization; or dust removal on the first coal smoke gas after desulfurization before heat exchange between the first coal smoke gas and the fourth air flue gas.

[0019] The characteristics and advantages of the present invention are:

[0020] The heating furnace flue gas coordinated heating desulfurization and denitrification system and method of the present invention realizes the self-heat exchange of air flue gas in its desulfurization and denitrification process by setting an air-to-smoke heat exchanger, realizes the self-heat exchange of coal flue gas in its desulfurization and denitrification process by setting a coal-to-smoke heat exchanger, and realizes the heat exchange between air flue gas and coal flue gas by setting an air-to-coal heat exchanger, thereby realizing full utilization of the heat of air flue gas and coal flue gas, and using air flue gas to balance the temperature of coal flue gas, thereby reducing energy consumption. In addition, when the temperature fluctuations of coal flue gas and air flue gas introduced into the heating furnace flue gas coordinated heating desulfurization and denitrification system occur, the temperature of coal flue gas and air flue gas before denitrification and before desulfurization and dust removal can be adjusted through heat exchange, thereby ensuring the stable operation of the heating furnace flue gas coordinated heating desulfurization and denitrification system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a connection diagram of a heating furnace flue gas coordinated heating desulfurization and denitrification system in one embodiment of the present invention.

[0023] Figure 2 It is a schematic diagram of the operation of the heating furnace flue gas coordinated heating desulfurization and denitrification system in one embodiment of the present invention.

[0024] Figure 3 It is a connection diagram of a heating furnace flue gas coordinated heating desulfurization and denitrification system in another embodiment of the present invention.

[0025] Figure 4 It is a schematic diagram of the operation of a heating furnace flue gas coordinated heating desulfurization and denitrification system in another embodiment of the present invention.

[0026] In the figure:

[0027] 11. Air-smoke heat exchanger; 111. First air-smoke heat absorption pipeline; 112. First air-smoke heat release pipeline; 12. Air-smoke denitrification structure; 13. Air-smoke desulfurization structure; 14. Air-smoke dust removal structure;

[0028] 21. Soot heat exchanger; 211. First soot heat absorption pipeline; 212. First soot heat release pipeline; 22. Soot denitrification structure; 23. Soot desulfurization structure; 24. Soot dust removal structure;

[0029] 3. Air-coal heat exchanger; 31. Second coal smoke heat absorption pipeline; 32. Second air-smoke heat release pipeline;

[0030] 4. Heat supplement mechanism; 41. Hot air furnace; 42. Soot heat supplement structure; 43. Air smoke heat supplement structure;

[0031] 5. Air smoke exhaust fan;

[0032] 6. Coal smoke induced draft fan;

[0033] 7. Chimney for empty smoke emission;

[0034] 8. Chimneys for emission of coal smoke;

[0035] 100. Coal smoke system; 200. Air smoke system. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Implementation Method 1

[0038] like Figure 1 and Figure 3As shown, the present invention provides a heating furnace flue gas coordinated heating desulfurization and denitrification system, including: an air smoke desulfurization and denitrification mechanism, including an air smoke heat exchanger 11, an air smoke denitrification structure 12 and an air smoke desulfurization structure 13, the air smoke heat exchanger 11 has a first air smoke heat absorption pipeline 111 and a first air smoke heat release pipeline 112 capable of heat exchange, the first air smoke heat absorption pipeline 111 is connected to the upstream of the air smoke denitrification structure 12, and the first air smoke heat release pipeline 112 is connected to the downstream of the air smoke denitrification structure 12; a coal smoke desulfurization and denitrification mechanism, including a coal smoke heat exchanger 21, a coal smoke denitrification structure 22 and a coal smoke desulfurization structure 23, the coal smoke heat exchanger 21 has a first coal smoke heat absorption pipeline 211 and a first air smoke heat release pipeline 112 capable of heat exchange The soot heat release pipeline 212, the first soot heat absorption pipeline 211 is connected to the upstream of the soot denitration structure 22, and the first soot heat release pipeline 212 is connected to the downstream of the soot denitration structure 22; the air-coal heat exchanger 3 has a second soot heat absorption pipeline 31 and a second air-smoke heat release pipeline 32 capable of heat exchange, the second soot heat absorption pipeline 31 is connected to the upstream of the soot heat exchanger 21, the second air-smoke heat release pipeline 32 is connected to the downstream of the air-smoke heat exchanger 11, the air-smoke desulfurization structure 13 is connected to the downstream of the second air-smoke heat release pipeline 32 or the upstream of the first air-smoke heat absorption pipeline 111, and the soot desulfurization structure 23 is connected to the upstream of the second soot heat absorption pipeline 31 or the downstream of the first soot heat release pipeline 212.

[0039] The heating furnace flue gas coordinated heating desulfurization and denitrification system of the present invention realizes the self-heat exchange of air flue gas in its desulfurization and denitrification process by setting an air flue gas heat exchanger 11, realizes the self-heat exchange of coal flue gas in its desulfurization and denitrification process by setting a coal flue gas heat exchanger 21, and realizes the heat exchange between air flue gas and coal flue gas by setting an air-coal heat exchanger 3, thereby realizing the full utilization of the heat of air flue gas and coal flue gas, and using air flue gas to balance the temperature of coal flue gas, thereby reducing energy consumption. In addition, when the temperature fluctuations of coal flue gas and air flue gas introduced into the heating furnace flue gas coordinated heating desulfurization and denitrification system occur, the temperature of coal flue gas and air flue gas before denitrification and before desulfurization and dust removal can be adjusted through heat exchange, thereby ensuring the stable operation of the heating furnace flue gas coordinated heating desulfurization and denitrification system.

[0040] Since the air smoke system 200 of the oriented silicon steel heating furnace has a relatively high air smoke temperature, the heating furnace flue gas coordinated heating desulfurization and denitrification system of the present invention is particularly suitable for oriented silicon steel heating furnaces, and can make full use of the heat of the air smoke by using the air-coal heat exchanger 3 and the air-smoke heat exchanger 11, and can also avoid the air smoke temperature after denitration being too high to damage the downstream processing equipment of the air smoke denitration structure 12. Specifically, Figure 1 and Figure 3 As shown, the air smoke system 200 of the oriented silicon steel heating furnace is connected upstream of the smoke desulfurization and denitrification mechanism; the coal smoke desulfurization and denitrification mechanism is connected upstream of the coal smoke system 100 of the oriented silicon steel heating furnace.

[0041] Of course, the heating furnace flue gas coordinated heating desulfurization and denitrification system of the present invention can also be applied to other heating furnaces and can also produce the above-mentioned beneficial effects.

[0042] Specifically, Figure 1 and Figure 3 As shown, the air smoke desulfurization structure 13 and the coal smoke desulfurization structure 23 are both dry desulfurization structures, and the air smoke denitration structure 12 and the coal smoke denitration structure 22 are both SCR denitration structures. The air smoke desulfurization and denitration mechanism also includes an air smoke dust removal structure 14, which is connected to the downstream of the air smoke desulfurization structure 13; the coal smoke desulfurization and denitration mechanism also includes a coal smoke dust removal structure 24, which is connected to the downstream of the coal smoke desulfurization structure 23. The air smoke desulfurization and denitration mechanism is connected to an air smoke induced draft fan 5 downstream; the coal smoke desulfurization and denitration mechanism is connected to a coal smoke induced draft fan 6 downstream. The output end of the air smoke induced draft fan 5 is connected to an air smoke emission chimney 7, and the output end of the coal smoke induced draft fan 6 is connected to a coal smoke emission chimney 8.

[0043] Among them, the air smoke dust removal structure 14 and the coal smoke dust removal structure 24 both include but are not limited to the use of bag dust collectors. The flue gas is fully mixed with the ammonia generated by the ammonia evaporator at the inlet of the SCR reactor of the SCR denitrification structure through the ammonia spray grid, and the NOx in the flue gas undergoes a reduction reaction under the action of the catalyst to convert into nitrogen and water, thereby achieving the purpose of removing NOx. The desulfurization injection point is selected to be set on the flue in front of the desulfurization reactor of the dry desulfurization structure. In the desulfurization reactor, SO2 in the flue gas reacts with the dry desulfurizer and is removed. The flue gas after desulfurization enters the bag dust collector, and the solid products generated by desulfurization are efficiently captured by the bag dust collector together with the smoke in the flue gas. The air smoke after denitrification and desulfurization and dust removal is discharged through the air smoke exhaust chimney by the air smoke induced draft fan; the coal smoke after denitrification and desulfurization and dust removal is discharged through the coal smoke exhaust chimney by the coal smoke induced draft fan.

[0044] like Figure 2 and Figure 4 As shown, the heating furnace flue gas coordinated heating desulfurization and denitrification system of the present invention is in the stable operation stage: the air-to-gas heat exchanger 11 is used to perform heat exchange on the first air-to-gas before denitrification and the second air-to-gas after denitrification, so that the first air-to-gas is heated to obtain the third air-to-gas, and the second air-to-gas is cooled to obtain the fourth air-to-gas; the air-to-coal heat exchanger 3 is used to perform heat exchange on the first coal-to-gas before denitrification and the fourth air-to-gas, so that the first coal-to-gas is heated to obtain the second coal-to-gas, and the fourth air-to-gas is cooled to obtain the fifth air-to-gas; the coal-to-gas heat exchanger 21 is used to perform heat exchange on the second coal-to-gas and the third coal-to-gas after denitrification, so that the second coal-to-gas is heated to obtain the fourth coal-to-gas, and the third coal-to-gas is cooled to obtain the fifth coal-to-gas.

[0045] like Figure 1 and Figure 3As shown, the positions of the air smoke desulfurization structure 13 for desulfurizing air smoke and the coal smoke desulfurization structure 23 for desulfurizing coal smoke can be set according to the temperature of the air smoke and the temperature of the coal smoke at different nodes, that is, when the temperature meets the requirements, it is preferred that the temperature does not exceed 200°C. The air smoke desulfurization structure 13 can be set upstream of the air smoke denitrification structure 12 to desulfurize the air smoke before the air smoke is denitrified, or it can be set downstream of the air smoke denitrification structure 12 to desulfurize the air smoke after the air smoke is denitrified; the coal smoke desulfurization structure 23 can be set upstream of the coal smoke denitrification structure 22 to desulfurize the coal smoke before the coal smoke is denitrified, or it can be set downstream of the coal smoke denitrification structure 22 to desulfurize the coal smoke after the coal smoke is denitrified. Of course, in order to more effectively utilize the heat of air smoke and coal smoke and avoid heat loss during the desulfurization process, as Figure 1 As shown, the air smoke desulfurization structure 13 is preferably arranged downstream of the air smoke denitrification structure 12 , and the coal smoke desulfurization structure 23 is arranged downstream of the coal smoke denitrification structure 22 .

[0046] like Figure 1 and Figure 2 As shown, in some embodiments of the present invention, the first air flue gas is the air flue gas led out of the air flue system 200, that is, the input end of the first air flue heat absorption pipeline 111 is connected to the air flue system 200; the air flue desulfurization structure 13 is connected to the downstream of the second air flue heat release pipeline 32, and the fifth air flue gas after heat release and temperature reduction in the second air flue heat release pipeline 32 is desulfurized to obtain the sixth air flue gas. Furthermore, the sixth air flue gas after denitration and desulfurization is dusted by the air flue dust removal structure 14.

[0047] In some other embodiments of the present invention, the air-to-gas desulfurization structure 13 is connected to the upstream of the first air-to-gas heat absorption pipeline 111, and the input end of the air-to-gas desulfurization structure 13 is connected to the air-to-gas system 200, that is, the air-to-gas flue gas drawn out of the air-to-gas system 200 is first desulfurized by the air-to-gas desulfurization structure 13 to obtain the first air-to-gas flue gas. Before the first air-to-gas flue gas is heat-exchanged with the second air-to-gas flue gas, the air-to-gas dust removal structure 14 is used to remove dust from the first air-to-gas flue gas after desulfurization.

[0048] like Figure 1 and Figure 2 As shown, in some embodiments of the present invention, the first coal smoke is the coal smoke from the coal smoke system 100, that is, the input end of the second coal smoke heat absorption pipeline 31 is connected to the coal smoke system 100; the coal smoke desulfurization structure 23 is connected to the downstream of the first coal smoke heat release pipeline 212, and the fifth coal smoke is desulfurized after heat release and cooling in the first coal smoke heat release pipeline 212 to obtain the sixth coal smoke. Furthermore, the coal smoke dust removal structure 24 removes dust from the sixth air smoke after denitration and desulfurization.

[0049] like Figure 3 and Figure 4 As shown, in some other embodiments of the present invention, the soot desulfurization structure 23 is connected to the upstream of the second soot heat absorption pipeline 31, and the input end of the soot desulfurization structure 23 is connected to the soot system 100, that is, the soot flue gas drawn out of the soot system 100 is first desulfurized by the soot desulfurization structure 23 to obtain the first soot flue gas. Before the first soot flue gas is heat-exchanged with the fourth air flue gas, the desulfurized first soot flue gas is dust-removed by the soot dust removal structure 24. Before the first air flue gas is heat-exchanged with the second air flue gas, the desulfurized first air flue gas is dust-removed by the air flue dust removal structure 14.

[0050] like Figure 1 and Figure 3 As shown, in an embodiment of the present invention, the heating furnace flue gas coordinated heating desulfurization and denitrification system also includes a heat supplement mechanism 4, which includes a coal smoke heat supplement structure 42 and an air smoke heat supplement structure 43. The coal smoke heat supplement structure 42 is connected to the upstream of the coal smoke denitrification structure 22 and can supplement heat for the coal smoke flue gas before denitrification. The air smoke heat supplement structure 43 is connected to the upstream of the air smoke denitrification structure 12 and can supplement heat for the air smoke flue gas before denitrification. By setting up the heat supplement mechanism 4, in the initial operation stage of the whole system, that is, before the air smoke and coal smoke start to denitrify and cannot exchange heat with the air smoke and coal smoke after denitrification, the coal smoke heat supplement structure 42 can be used to supplement heat for the coal smoke, and the air smoke heat supplement structure 43 can be used to supplement heat for the air smoke; in addition, in the stable operation stage, when the self-heat exchange of the air smoke and the self-heat exchange of the coal smoke and the heat exchange between the air smoke and the coal smoke cannot meet the demand, the coal smoke heat supplement structure 42 can be used to supplement heat for the coal smoke, and the air smoke heat supplement structure 43 can be used to supplement heat for the air smoke.

[0051] In a specific embodiment of the present invention, Figure 2 As shown, the temperature of the first air flue gas drawn out by the air flue system 200 is 200°C. In the stable operation stage, the first air flue gas absorbs heat through the first air flue heat absorption pipeline 111 and heats up to the third air flue gas with a temperature of 250°C. The third air flue gas is heated up to the seventh air flue gas with a temperature of 280°C through the air flue heat supplementation structure 43. The seventh air flue gas is denitrated by the air flue denitration structure 12 to obtain the second air flue gas with a substantially constant temperature. The second air flue gas is cooled down to the fourth air flue gas with a temperature of 230°C through the first air flue heat release pipeline 112. The fourth air flue gas is cooled down to the fifth air flue gas with a temperature of 200°C through the second air flue heat release pipeline 32. Then, the fifth air flue gas enters the air flue desulfurization structure 13 for desulfurization. After the desulfurization, the air flue gas is cooled down to 190°C and enters the air flue dust removal structure 14 for dust removal.

[0052] In the initial operation stage, since the second air smoke is not introduced into the first air smoke heat release pipeline 112, the first air smoke cannot absorb heat and heat up through the first air smoke heat absorption pipeline 111. Therefore, the first air smoke is directly heated up by the air smoke heat supplement structure 43 to be heated to the seventh air smoke with a temperature of 280°C, until the second air smoke generated by the seventh air smoke being treated by the air smoke denitrification structure 12 can be stably introduced into the first air smoke heat release pipeline 112.

[0053] like Figure 2 As shown, the temperature of the first soot flue gas drawn out by the soot system 100 is 150°C. In the stable operation stage, the first soot flue gas absorbs heat through the second soot heat absorption pipeline 31 and is heated to become the second soot flue gas with a temperature of 180°C, the second soot flue gas absorbs heat through the first soot heat absorption pipeline 211 and is heated to become the fourth soot flue gas with a temperature of 250°C, the fourth soot flue gas is heated to become the seventh soot flue gas with a temperature of 280°C through the soot supplementary heat structure 42, the seventh soot flue gas is denitrated through the soot denitration structure 22 to obtain the third soot flue gas with a substantially constant temperature, the third soot flue gas is deheated through the first soot heat release pipeline 212 and is cooled to become the fifth soot flue gas with a temperature of 210°C, the fifth air flue gas enters the soot desulfurization structure 23 for desulfurization, and the soot flue gas after desulfurization is cooled to 200°C and enters the soot dust removal structure 24 for dust removal.

[0054] In the initial operation stage, since the fourth air smoke is not introduced into the second air smoke heat release pipeline 32, the first coal smoke cannot absorb heat and heat up through the second coal smoke heat absorption pipeline 31, and the third coal smoke is not introduced into the first coal smoke heat release pipeline 212, so the second coal smoke cannot absorb heat and heat up through the first coal smoke heat absorption pipeline 211. Therefore, the first coal smoke is directly heated by the coal smoke heat supplement structure 42 to be heated to the seventh coal smoke with a temperature of 280°C, until the third coal smoke generated by the seventh coal smoke treated by the coal smoke denitrification structure 22 can be stably introduced into the first coal smoke heat release pipeline 212, and the fourth air smoke generated by the second air smoke generated by the air smoke denitrification structure 12 after heat release through the first air smoke heat release pipeline 112 can be stably introduced into the second air smoke heat release pipeline 32.

[0055] Therefore, the present invention can make use of the cooperation of the air-smoke heat exchanger 11, the coal-smoke heat exchanger 21, the air-coal heat exchanger 3 and the supplementary heat mechanism 4 to make the temperature of the air-smoke flue gas entering the air-smoke denitration structure 12 and the coal-smoke flue gas entering the coal-smoke denitration structure 22 equal, so that the same catalyst can be used for denitration treatment, and the temperature of the air-smoke flue gas entering the air-smoke desulfurization structure 13 and the coal-smoke flue gas entering the coal-smoke desulfurization structure 23 can be equal, so that the desulfurization treatment is carried out at the same temperature, which is convenient for the operation and management of the entire system. In addition, compared with the prior art, since the present invention realizes the full utilization of the heat of the air-smoke flue gas and the coal-smoke flue gas themselves, the supplementary heat demand of the supplementary heat mechanism 4 can be reduced to the maximum extent.

[0056] like Figure 1 and Figure 2 As shown, in the embodiment of the present invention, the heat supplement mechanism 4 also includes a hot blast furnace 41, which is used to provide heat supplement flue gas, so that the heat supplement flue gas is used to exchange heat with air flue gas and coal smoke, so that the air smoke and coal smoke absorb heat and heat up. The coal smoke heat supplement structure 42 has a coal smoke heat supplement pipeline and a first heat supplement flue gas heat release pipeline that can perform heat exchange. The coal smoke heat supplement pipeline is connected between the first coal smoke heat absorption pipeline 211 and the coal smoke denitration structure 22, and the first heat supplement flue gas heat release pipeline is connected to the flue of the hot blast furnace 41. The air-smoke heat supplement structure 43 has a mixed heat exchange pipeline that can mix the heat supplement flue gas with the air-smoke flue gas for heat exchange. The mixed heat exchange pipeline is connected between the first air-smoke heat absorption pipeline 111 and the air-smoke denitration structure 12 and is connected to the flue of the hot blast furnace 41, so that the heat supplement flue gas can be mixed with the air-smoke flue gas and then discharged after denitration, desulfurization and dust removal treatment, thereby ensuring that the heat supplement flue gas can also be stably discharged up to standard. In addition, in order to fully utilize the heat of the heat supplement flue gas and further reduce energy consumption, the hot blast furnace 41, the first heat supplement flue gas heat release pipeline and the mixed heat exchange pipeline are connected in sequence along the conveying direction of the heat supplement flue gas, thereby realizing the gradient heat exchange of the heat supplement flue gas. In this embodiment, the air-smoke heat exchanger 11, the coal smoke heat exchanger 21, the air-coal heat exchanger 3 and the coal smoke heat supplement structure 42 are all plate heat exchangers.

[0057] Implementation Method 2

[0058] The present invention also provides a method for coordinated heating desulfurization and denitrification of flue gas from a heating furnace, which adopts a coordinated heating desulfurization and denitrification system for flue gas from a heating furnace. The specific structure, working principle and beneficial effects of the coordinated heating desulfurization and denitrification system for flue gas from a heating furnace in this embodiment are the same as those of the coordinated heating desulfurization and denitrification system for flue gas from a heating furnace in the first embodiment, which will not be repeated here. And because the principle of solving the problem by the method of the present invention is similar to that of the coordinated heating desulfurization and denitrification system for flue gas from a heating furnace in the first embodiment, the implementation of the method of the present invention can refer to the implementation of the coordinated heating desulfurization and denitrification system for flue gas from a heating furnace in the first embodiment, and the repeated parts will not be repeated.

[0059] Combination Figures 1 to 4As shown, the method for coordinated heating desulfurization and denitrification of flue gas from a heating furnace of the present invention comprises the following steps: heat exchanging the first air smoke before denitration with the second air smoke after denitration, so that the first air smoke is heated to obtain the third air smoke, and the second air smoke is cooled to obtain the fourth air smoke; heat exchanging the first coal smoke before denitration with the fourth air smoke, so that the first coal smoke is heated to obtain the second coal smoke, and the fourth air smoke is cooled to obtain the fifth air smoke; heat exchanging the second coal smoke with the third coal smoke after denitration, so that the first coal smoke is heated to obtain the second coal smoke, and the fourth air smoke is cooled to obtain the fifth air smoke; The second coal smoke flue gas is heated to obtain the fourth coal smoke flue gas, and the third coal smoke flue gas is cooled to obtain the fifth coal smoke flue gas; wherein, the first air smoke flue gas is the air smoke flue gas drawn out from the air smoke system 200, and the fifth air smoke flue gas is desulfurized to obtain the sixth air smoke flue gas; or the air smoke flue gas drawn out from the air smoke system 200 is desulfurized to obtain the first air smoke flue gas; wherein, the first coal smoke flue gas is the coal smoke flue gas drawn out from the coal smoke system 100, and the fifth coal smoke flue gas is desulfurized to obtain the sixth coal smoke flue gas; or the coal smoke flue gas drawn out from the coal smoke system 100 is desulfurized to obtain the first coal smoke gas.

[0060] In an embodiment of the present invention, the method also includes the following steps: exchanging heat between the fourth coal smoke and the first supplementary heat flue gas, so that the fourth coal smoke is heated to obtain the seventh coal smoke, and the first supplementary heat flue gas is cooled to obtain the second supplementary heat flue gas; and denitrifying the seventh coal smoke to obtain the third coal smoke.

[0061] In an embodiment of the present invention, the method further comprises the following steps: exchanging heat between the third air flue gas and the second heat supplementary flue gas to heat the third air flue gas to obtain the seventh air flue gas; and denitrifying the seventh air flue gas to obtain the second air flue gas.

[0062] In the embodiment of the present invention, the temperature of the seventh coal smoke is equal to that of the seventh air smoke. In this embodiment, the heat exchange method of the third air smoke and the second supplementary heat smoke is mixed heat exchange, that is, the temperature of the smoke after the mixed heat exchange of the third air smoke and the second supplementary heat smoke is equal to that of the seventh coal smoke.

[0063] In an embodiment of the present invention, the method also includes the following steps: dusting the sixth air flue gas after denitrification and desulfurization; or dusting the first air flue gas after desulfurization before the first air flue gas is heat exchanged with the second air flue gas; dusting the sixth coal smoke gas after denitrification and desulfurization; or dusting the first coal smoke gas after desulfurization before the first coal smoke gas is heat exchanged with the fourth air flue gas.

[0064] The above are only several embodiments of the present invention. Those skilled in the art may make various changes or modifications to the embodiments of the present invention based on the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A heating furnace flue gas coordinated heating desulfurization and denitrification system, characterized in that: include: An air smoke desulfurization and denitrification mechanism comprises an air smoke heat exchanger, an air smoke denitrification structure and an air smoke desulfurization structure, wherein the air smoke heat exchanger has a first air smoke heat absorption pipeline and a first air smoke heat release pipeline capable of heat exchange, wherein the first air smoke heat absorption pipeline is connected to the upstream of the air smoke denitrification structure, and the first air smoke heat release pipeline is connected to the downstream of the air smoke denitrification structure; A soot desulfurization and denitration mechanism, comprising a soot heat exchanger, a soot denitration structure and a soot desulfurization structure, wherein the soot heat exchanger has a first soot heat absorption pipeline and a first soot heat release pipeline capable of heat exchange, wherein the first soot heat absorption pipeline is connected to the upstream of the soot denitration structure, and the first soot heat release pipeline is connected to the downstream of the soot denitration structure; The air-coal heat exchanger has a second coal smoke heat absorption pipeline and a second air-smoke heat release pipeline capable of heat exchange, wherein the second coal smoke heat absorption pipeline is connected to the upstream of the coal smoke heat exchanger, and the second air-smoke heat release pipeline is connected to the downstream of the air-smoke heat exchanger, the air-smoke desulfurization structure is connected to the downstream of the second air-smoke heat release pipeline or the upstream of the first air-smoke heat absorption pipeline, and the coal smoke desulfurization structure is connected to the upstream of the second coal smoke heat absorption pipeline or the downstream of the first coal smoke heat release pipeline.

2. The heating furnace flue gas coordinated heating desulfurization and denitrification system according to claim 1, characterized in that: The heating furnace flue gas coordinated heating desulfurization and denitrification system also includes a heat supplement mechanism, which includes a coal smoke heat supplement structure and an air smoke heat supplement structure. The coal smoke heat supplement structure is connected to the upstream of the coal smoke denitrification structure and can supplement heat for the air smoke before denitrification. The air smoke heat supplement structure is connected to the upstream of the air smoke denitrification structure and can supplement heat for the air smoke before denitrification.

3. The heating furnace flue gas coordinated heating desulfurization and denitrification system according to claim 2, characterized in that: The heat supplement mechanism also includes a hot blast furnace, which is used to provide heat supplement flue gas; the coal smoke heat supplement structure has a coal smoke heat supplement pipeline capable of heat exchange and a first heat supplement flue gas heat release pipeline, and the coal smoke heat supplement pipeline is connected between the first coal smoke heat absorption pipeline and the coal smoke denitrification structure; the air smoke heat supplement structure is provided with a mixed heat exchange pipeline, and the mixed heat exchange pipeline is connected between the first air smoke heat absorption pipeline and the air smoke denitrification structure; the hot blast furnace, the first heat supplement flue gas heat release pipeline and the mixed heat exchange pipeline are connected in sequence along the conveying direction of the heat supplement flue gas.

4. The heating furnace flue gas coordinated heating desulfurization and denitrification system according to any one of claims 1 to 3, characterized in that: The air-smoke desulfurization structure and the coal smoke desulfurization structure are both dry desulfurization structures, and the air-smoke denitrification structure and the coal smoke denitrification structure are both SCR denitrification structures.

5. The heating furnace flue gas coordinated heating desulfurization and denitrification system according to any one of claims 1 to 3, characterized in that: The air smoke desulfurization and denitrification mechanism is connected upstream to the air smoke system of the oriented silicon steel heating furnace; the coal smoke desulfurization and denitrification mechanism is connected upstream to the coal smoke system of the oriented silicon steel heating furnace.

6. The heating furnace flue gas coordinated heating desulfurization and denitrification system according to any one of claims 1 to 3, characterized in that: The air smoke desulfurization and denitrification mechanism further includes an air smoke dust removal structure, which is connected to the downstream of the air smoke desulfurization structure; the coal smoke desulfurization and denitrification mechanism further includes a coal smoke dust removal structure, which is connected to the downstream of the coal smoke desulfurization structure.

7. The heating furnace flue gas coordinated heating desulfurization and denitrification system according to any one of claims 1 to 3, characterized in that: An air smoke induced draft fan is connected to the downstream of the air smoke desulfurization and denitrification mechanism; and a coal smoke induced draft fan is connected to the downstream of the coal smoke desulfurization and denitrification mechanism.

8. A method for desulfurization and denitrification of flue gas from a heating furnace by coordinated heating, characterized in that: A heating furnace flue gas coordinated heating desulfurization and denitrification system according to any one of claims 1 to 7 is used; the method comprises the following steps: Performing heat exchange between the first air flue gas before denitration and the second air flue gas after denitration, so that the first air flue gas is heated to obtain the third air flue gas, and the second air flue gas is cooled to obtain the fourth air flue gas; wherein the first air flue gas is the air flue gas drawn out of the air flue system or the air flue gas after desulfurization; Performing heat exchange between the first coal smoke before denitration and the fourth air smoke, so that the first coal smoke is heated up to obtain the second coal smoke, and the fourth air smoke is cooled down to obtain the fifth air smoke; The second soot gas is heat exchanged with the third soot gas after denitration, so that the second soot gas is heated to obtain the fourth soot gas, and the third soot gas is cooled to obtain the fifth soot gas; Wherein, the first air flue gas is the air flue gas led out of the air flue system, and the sixth air flue gas is obtained by desulfurization of the fifth air flue gas; or the first air flue gas is obtained by desulfurization of the air flue gas led out of the air flue system; The first coal smoke is the coal smoke drawn out from the coal smoke system, and the fifth coal smoke is desulfurized to obtain the sixth coal smoke; or the coal smoke drawn out from the coal smoke system is desulfurized to obtain the first coal smoke.

9. The method for coordinated heating desulfurization and denitrification of flue gas from a heating furnace according to claim 8, characterized in that: The method further comprises the following steps: The fourth coal smoke and the first supplementary heat flue gas are heat exchanged to increase the temperature of the fourth coal smoke to obtain the seventh coal smoke and the first supplementary heat flue gas is cooled to obtain the second supplementary heat flue gas; The seventh coal smoke is subjected to denitrification treatment to obtain the third coal smoke.

10. The method for coordinated heating and desulfurization and denitrification of flue gas from a heating furnace according to claim 9, characterized in that: The method further comprises the following steps: exchanging heat between the third air flue gas and the second supplementary heat flue gas, so that the third air flue gas is heated to obtain seventh air flue gas; The seventh air flue gas is subjected to denitration treatment to obtain the second air flue gas.

11. The method for coordinated heating desulfurization and denitrification of flue gas from a heating furnace according to claim 10, characterized in that: The seventh coal smoke flue gas and the seventh air smoke flue gas have the same temperature.

12. The method for coordinated heating desulfurization and denitrification of flue gas from a heating furnace according to claim 10, characterized in that: The method further comprises the following steps: Dust removal is performed on the sixth air flue gas after denitration and desulfurization; or dust removal is performed on the first air flue gas after desulfurization before heat exchange between the first air flue gas and the second air flue gas; The sixth coal smoke after denitration and desulfurization is subjected to dust removal; or the first coal smoke after desulfurization is subjected to dust removal before the first coal smoke is heat-exchanged with the fourth air smoke.

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