A heating system for SCR denitrification in steel rolling heating furnace

Abstract

The present invention provides a heating system for SCR denitrification of a steel rolling heating furnace, which belongs to the technical field of flue gas denitrification. The heating system for SCR denitrification of a steel rolling heating furnace comprises a smoke inlet channel, an air preheater, a smoke distribution device, a static mixer and a denitrification reactor connected in sequence. A temperature regulating pipe is further provided between the smoke inlet channel and the smoke distribution device. A first mass flow controller and a spray box are sequentially provided on the temperature regulating pipe along the flow direction of the smoke. The liquid inlet of the spray box has a fourth mass flow controller. A second mass flow controller is further provided on the smoke inlet channel, and the second mass flow controller is located between the smoke inlet of the temperature regulating pipe and the smoke inlet of the air preheater. The smoke temperature at the smoke inlet of the smoke inlet channel is greater than the smoke temperature at the smoke outlet of the temperature regulating pipe, and the smoke temperature at the smoke outlet of the temperature regulating pipe is greater than the smoke outlet temperature of the air preheater.

Description

Technical Field

[0001] The invention belongs to the technical field of flue gas denitration, and in particular relates to a heating system for SCR denitration of a steel rolling heating furnace. Background Art

[0002] In order to protect the environment, steel rolling heating furnaces that use natural gas or coke oven gas as fuel need to denitrify the flue gas produced. In the existing short-process steel industry, the flue gas emission process of the steel rolling heating furnace is as follows: the heating furnace produces high-temperature flue gas (500~700℃), which first passes through the air preheater. The principle of the air preheater is to use high-temperature flue gas to preheat the air. While the air is heated, the flue gas is cooled (100~200℃). Finally, the flue gas flowing out of the air preheater is further cooled through the waste heat boiler before being discharged. The process of denitrification of the flue gas during the emission process is basically designed on the flue between the air preheater and the waste heat boiler, but the operating temperature of the existing mature denitrification catalyst is basically above 200℃. The temperature of the flue gas flowing out after passing through the air preheater is lower than the operating temperature of the denitrification catalyst, which makes the denitrification efficiency of the flue gas low and cannot ensure that the flue gas emissions meet the standards. Summary of the invention

[0003] The embodiment of the present invention provides a heating system for SCR denitrification of a steel rolling heating furnace, aiming to solve the technical problem that the temperature of the existing flue gas after cooling by an air preheater is lower than the operating temperature of the denitrification catalyst, the denitrification efficiency of the flue gas is low, and the flue gas emission cannot be guaranteed to meet the standards.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: to provide a heating system for SCR denitration of a steel rolling heating furnace, comprising a smoke inlet channel, an air preheater, a smoke distribution device, a static mixer and a denitration reactor connected in sequence, a temperature regulating pipeline is also provided between the smoke inlet channel and the smoke distribution device, a first mass flow controller and a spray box are sequentially provided on the temperature regulating pipeline along the flow direction of the smoke, the spray box is used to atomize the reducing agent, the liquid inlet of the spray box has a fourth mass flow controller, a second mass flow controller is also provided on the smoke inlet channel, and the second mass flow controller is located between the temperature regulating pipeline and the air preheater;

[0005] Among them, after the flue gas passes through the first mass flow controller and the second mass flow controller, the flue gas flow entering the temperature control pipe and the air preheater can be measured respectively, and the fourth mass flow controller adjusts the amount of reducing agent according to the amount of flue gas passing through the first mass flow controller.

[0006] In a possible implementation, the air preheater has an air inlet and an air outlet, an air branch pipe connecting the air inlet and the air outlet is provided outside the air preheater, and a third mass flow controller is provided at the air branch pipe and the air inlet;

[0007] The two third mass flow controllers are used to adjust the amount of cold air entering the air preheater so that the flue gas temperature at the smoke outlet of the air preheater is within a preset range.

[0008] In a possible implementation, the heating system for SCR denitrification in a steel rolling heating furnace also includes a control system, and the first mass flow controller, the second mass flow controller, the third mass flow controller and the fourth mass flow controller are all communicatively connected to the control system.

[0009] In a possible implementation, the preset range is 100°C to 200°C.

[0010] In one possible implementation, the spray box includes a box body, a liquid supply pipe connected to the box body, an injection body arranged between the liquid supply pipe and the box body, and an atomizing nozzle connected to the injection body and extending into the box body, the box body has an inlet and an outlet connected to the temperature control pipe, and the fourth mass flow controller is arranged on the liquid supply pipe.

[0011] In a possible implementation, the smoke distribution device includes a disc and a plurality of smoke outlet pipes arranged at one axial end of the disc, the interior of the disc is provided with a accommodating cavity, and the outer periphery is provided with two smoke inlets, one of the smoke inlets is connected to the smoke outlet side of the temperature control pipe, and the other smoke inlet is connected to the smoke outlet side of the air preheater, the axial direction of the smoke outlet pipe forms an acute angle with the axial direction of the disc, and the plurality of smoke outlet pipes are evenly distributed around the axis of the disc.

[0012] In a possible implementation, an adjusting tube is further connected between the smoke outlet pipe and the disc, and the adjusting tube includes a corrugated tube located on an outer layer, a rubber tube located on an inner layer, and a supporting wire arranged between the corrugated tube and the rubber tube, wherein both ends of the supporting wire are respectively connected to the disc and the smoke outlet pipe, and the adjusting tube is used to adjust the smoke outlet direction of the smoke outlet pipe.

[0013] In a possible implementation, the static mixer includes a main body and a plurality of casings sleeved on the main body, the plurality of casings are spaced apart along the axial direction of the main body, the main body has a plurality of mixing chambers therein, the plurality of mixing chambers are spaced apart along the axial direction of the main body, and correspond one-to-one to the plurality of casings, the mixing chamber located at the head end is connected to the flue gas distribution device, the mixing chamber located at the end is connected to the denitrification reactor, second through holes connected to the casings are provided on opposite sides of each mixing chamber, and each casing is provided with two bifurcated tubes connected to adjacent mixing chambers, and the two bifurcated tubes are arranged opposite to each other.

[0014] In a possible implementation, the temperature of the smoke flowing out of the smoke outlet of the temperature-adjusting pipe is 450° C. to 600° C.

[0015] In a possible implementation, the temperature of the smoke flowing out of the smoke outlet of the static mixer is 200° C. to 250° C.

[0016] The scheme shown in the embodiment of the present application is compared with the prior art. The temperature of the flue gas in the steel rolling heating furnace after it flows out is 500~700℃. At this time, a part of the flue gas in the smoke inlet channel enters the temperature regulating pipe, and the other part enters the air preheater. The first mass flow controller calculates the amount of flue gas entering the temperature regulating pipe to obtain a first flue gas value, and the second mass flow controller calculates the amount of flue gas entering the air preheater to obtain a second flue gas amount. The fourth mass flow controller adjusts the amount of reducing agent introduced into the spray box according to the first flue gas value. When the flue gas passes through the spray box, due to the high temperature of the flue gas, the reducing agent in the spray box evaporates and mixes in this part of the flue gas. The flue gas entering the air preheater heats the cold air in the air preheater when passing through the air preheater. Finally, the flue gas at the smoke outlet of the air preheater and the smoke at the smoke outlet of the temperature regulating pipe are mixed in the flue gas mixer, and after mixing in the static mixer, the temperature of the flue gas meets the operating temperature of the denitration catalyst, and then enters the denitration reactor for normal denitration treatment and then is discharged. The temperature-raising system for SCR denitration in a steel-rolling heating furnace of the present invention can adjust the temperature through a temperature-adjusting pipe when the temperature of the flue gas at the smoke outlet of the air preheater is insufficient, thereby ensuring that the temperature of the flue gas meets the operating temperature of the denitration catalyst and improving the denitration efficiency of the flue gas; by configuring a spray box at the temperature-adjusting pipe, the high temperature of the flue gas can be used to directly evaporate the denitration reducing agent liquid, without the need to configure an ammonia evaporation process, thereby reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the main structure of a heating system for SCR denitration in a steel rolling heating furnace provided by an embodiment of the present invention;

[0018] Figure 2A schematic cross-sectional structure diagram of a static mixer used in an embodiment of the present invention;

[0019] Figure 3 A schematic cross-sectional view of a smoke distribution device used in an embodiment of the present invention;

[0020] Figure 4 This is a control principle diagram of the control system used in an embodiment of the present invention.

[0021] Description of reference numerals:

[0022] 10-smoke inlet channel; 11-second mass flow controller;

[0023] 20-air preheater; 21-air inlet; 22-air outlet; 23-air distribution duct; 24-third mass flow controller;

[0024] 30-smoke distribution device; 31-disc; 32-smoke outlet pipe; 33-adjusting pipe; 331-corrugated pipe; 332-rubber pipe; 333-support wire;

[0025] 40-static mixer; 41-main body; 42-housing; 43-mixing chamber; 44-bifurcated pipe;

[0026] 50- denitration reactor;

[0027] 60-temperature regulating pipe; 61-first mass flow controller; 62-spray box; 621-box; 622-liquid supply pipe; 623-spray body; 624-atomizing nozzle; 63-fourth mass flow controller;

[0028] 70-Control system. DETAILED DESCRIPTION

[0029] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] In the claims, description and the above-mentioned drawings of the present invention, unless otherwise clearly defined, the use of terms such as "first", "second" or "third" etc. are for distinguishing different objects rather than for describing a specific order.

[0031] Unless otherwise explicitly defined, the directional words in the claims, specification and the above-mentioned drawings of the present invention, such as the use of terms such as "upper", "lower", "top", "bottom", "front", "back", "inner", "outer", "center", "lateral", "longitudinal", "horizontal", "vertical", "left", "right", "clockwise", "counterclockwise", "high", "low", etc., indicating directions or positional relationships are based on the directions and positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the specific protection scope of the present invention.

[0032] In the claims, specification and the above drawings of the present invention, unless otherwise clearly defined, if the term "fixed connection" or "fixed connection" is used, it should be understood in a broad sense, that is, any connection method without a displacement relationship and relative rotation relationship between the two, that is to say, including non-detachable fixed connection, detachable fixed connection, integrated connection and fixed connection through other devices or elements.

[0033] In the claims, description and drawings of the present invention, if the terms "include", "have" and their variations are used, they are intended to mean "including but not limited to".

[0034] Please also read Figures 1 to 4 , the temperature-raising system for SCR denitration of a steel-rolling heating furnace provided by the present invention is now described. The temperature-raising system for SCR denitration of a steel-rolling heating furnace comprises a smoke inlet channel 10, an air preheater 20, a smoke distribution device 30, a static mixer 40 and a denitration reactor 50 connected in sequence, a temperature-adjusting pipe 60 is also provided between the smoke inlet channel 10 and the smoke distribution device 30, a first mass flow controller 61 and a spray box 62 are sequentially provided on the temperature-adjusting pipe 60 along the flow direction of the smoke, the spray box 62 is used to atomize the reducing agent, and the liquid inlet of the spray box 62 has a fourth mass flow controller 63, a second mass flow controller 11 is also provided on the smoke inlet channel 10, and the second mass flow controller 11 is located between the smoke inlet of the temperature-adjusting pipe 60 and the smoke inlet of the air preheater 20;

[0035] Among them, after the flue gas passes through the first mass flow controller 61 and the second mass flow controller 11, the flue gas flow rates entering the temperature control pipe 60 and the air preheater 20 can be measured respectively. The fourth mass flow controller 63 adjusts the amount of reducing agent through the amount of flue gas passing through the first mass flow controller 61. The flue gas temperature at the smoke inlet of the smoke inlet channel 10 is greater than the smoke temperature at the smoke outlet of the temperature control pipe 62, and the smoke temperature at the smoke outlet of the temperature control pipe 62 is greater than the smoke outlet temperature of the air preheater 20.

[0036] In a specific implementation, the temperature of the smoke flowing out of the smoke outlet of the temperature-adjusting pipe 60 is 450°C to 600°C; the temperature of the smoke flowing out of the smoke outlet of the static mixer 40 is 200°C to 250°C.

[0037] The heating system for SCR denitrification in a steel rolling heating furnace provided in this embodiment is compared with the prior art. The temperature of the flue gas in the steel rolling heating furnace after it flows out is 500-700°C. At this time, a part of the flue gas in the smoke inlet channel 10 enters the temperature regulating pipe 60, and the other part enters the air preheater 20. The first mass flow controller 61 calculates the amount of flue gas entering the temperature regulating pipe 60 to obtain a first flue gas value. The second mass flow controller 11 calculates the amount of flue gas entering the air preheater 20 to obtain a second flue gas amount. The fourth mass flow controller adjusts the amount of flue gas entering the spray box 62 according to the first flue gas value. The amount of the original agent, when the flue gas passes through the spray box 62, due to the high temperature of the flue gas, the reducing agent in the spray box 62 evaporates and mixes in the flue gas, and the flue gas entering the air preheater 20 heats the cold air in the air preheater 20 when passing through the air preheater 20, and finally the flue gas at the smoke outlet of the air preheater 20 and the smoke outlet of the temperature control pipe 60 are mixed in the flue gas mixer, and after mixing through the static mixer 40, the temperature of the flue gas meets the operating temperature of the denitration catalyst, and then enters the denitration reactor 50 for normal denitration treatment and discharge. The heating system for SCR denitration of the steel rolling heating furnace of the present invention can be used for temperature adjustment through the temperature control pipe 60 when the flue gas temperature at the smoke outlet of the air preheater 20 is insufficient, so as to ensure that the temperature of the flue gas meets the operating temperature of the denitration catalyst and improve the denitration efficiency of the flue gas; by configuring the spray box 62 at the temperature control pipe 60, the high temperature of the flue gas can be used to directly evaporate the denitration reducing agent liquid, without the need to configure an ammonia evaporation process, thereby reducing production costs.

[0038] In some embodiments, a specific implementation of the air preheater 20 can be as follows: Figure 1 See the structure shown. Figure 1 The air preheater 20 has an air inlet 21 and an air outlet 22. An air branch pipe 23 connecting the air inlet 21 and the air outlet 22 is provided outside the air preheater 20. A third mass flow controller 24 is provided at the air branch pipe 23 and the air inlet 21.

[0039] The two third mass flow controllers 24 are used to adjust the amount of cold air entering the air preheater 20 so that the flue gas temperature at the smoke outlet of the air preheater is within a preset range.

[0040] It should be noted that the preset range is 100°C~200°C.

[0041] The second mass flow controller 11 identifies the amount of flue gas entering the air preheater 20, and then adjusts the flow rate of cold air in the air preheater 20 according to the flue gas amount, so that the temperature at the smoke outlet of the air preheater 20 is within a preset range, thereby ensuring that the flue gas flowing out of the air preheater 20 and the flue gas flowing out of the temperature control pipe 60 can just meet the operating temperature of the denitrification catalyst after mixing, thereby improving the denitrification efficiency of the flue gas.

[0042] In some embodiments, an improved implementation of the above-mentioned heating system for SCR denitrification in a steel rolling heating furnace can be implemented as follows: Figure 4 See the structure shown. Figure 4 The heating system for SCR denitrification of steel rolling heating furnace also includes a control system 70, and the first mass flow controller 61, the second mass flow controller 11, the third mass flow controller 24 and the fourth mass flow controller 63 are all connected to the control system 70. The first mass flow controller 61, the second mass flow controller 11, the third mass flow controller 24 and the fourth mass flow controller 63 can be automatically adjusted by the control system 70. The staff only needs to set the respective proportional relationship in the control system 70 in advance, and the control system 70 can be adjusted in real time during operation, which is more convenient to use and simpler to operate.

[0043] It should be noted that the control system 70 can be a computer, a PLC system commonly used in factories, etc. The specific control process is exemplified as follows:

[0044] For example, the amount of flue gas in the temperature control pipe 60 needs to maintain a 2:1 ratio with the amount of reducing agent sprayed into the box body 621, and the amount of flue gas entering the air preheater 20 needs to maintain a 1:1 ratio with the amount of cold air passing through the air preheater 20; since the amount of flue gas generated by the heating furnace fluctuates in real time and is not constant, the amount of flue gas passing through the first mass flow controller 61 and the amount passing through the second mass flow controller 11 will fluctuate. The first mass flow controller 61 and the second mass flow controller 11 will transmit the amount of flue gas passing through to the control system 70 in real time. The control system 70 adjusts the third mass flow controller 24 and the fourth mass flow controller 63 according to the received numerical values, thereby ensuring that the amount of reducing agent entering the box body 621 and the amount of flue gas entering the temperature control pipe 60 maintain the above-mentioned proportional relationship, and similarly, ensuring that the amount of cold air and the amount of flue gas entering the air preheater 20 maintain the above-mentioned proportional relationship.

[0045] In some embodiments, a specific implementation of the spray box 62 can be as follows: Figure 1 See the structure shown. Figure 1The spray box 62 includes a box body 621, a liquid supply pipe 622 connected to the box body 621, an injection body 623 arranged between the liquid supply pipe 622 and the box body 621, and an atomizing nozzle 624 connected to the injection body 623 and extending into the box body 621. The box body 621 has an inlet and an outlet connected to the temperature control pipe 60, and a fourth mass flow controller 63 is arranged on the liquid supply pipe 622.

[0046] The injection body 623 is also connected to a compressed air pipe, which sprays the reducing agent provided by the liquid supply pipe 622 into the box body 621 through compressed air, so that the reducing agent is dispersed in the box body 621, thereby ensuring that the reducing agent can quickly evaporate and mix into the flue gas when the flue gas passes through, which can improve the evaporation efficiency of the reducing agent, shorten the residence time of the flue gas, and has little effect on the temperature of the flue gas, thereby ensuring the heating effect of the flue gas at the smoke outlet of the temperature control pipe 60 on the smoke outlet of the air preheater 20.

[0047] In some implementations, a specific implementation of the smoke distribution device 30 may be as follows: Figure 3 See the structure shown. Figure 3 The smoke distribution device 30 includes a disc 31 and a plurality of smoke outlet pipes 32 arranged at one axial end of the disc 31. The disc 31 is provided with a containing cavity inside and two smoke inlets are arranged on the outer circumference. One smoke inlet is connected to the smoke outlet side of the temperature regulating pipe 60, and the other smoke inlet is connected to the smoke outlet side of the air preheater 20. The axial direction of the smoke outlet pipe 32 forms an acute angle with the axial direction of the disc 31, and the plurality of smoke outlet pipes 32 are evenly distributed around the axis of the disc 31. The smoke at the outlet of the temperature regulating pipe 60 and the air preheater 20 enters the disc 31 through the two smoke inlets, and is evenly distributed to the plurality of smoke outlet pipes 32 to flow out, so that the smoke can be evenly distributed, which is convenient for subsequent mixing in the static mixer 40.

[0048] In some embodiments, an improved implementation of the above-mentioned smoke distribution device 30 can be adopted as follows Figure 3 See the structure shown. Figure 3 An adjusting tube 33 is also connected between the smoke outlet pipe 32 and the disc 31. The adjusting tube 33 includes a corrugated tube 331 located at the outer layer, a rubber tube 332 located at the inner layer, and a supporting wire 333 arranged between the corrugated tube 331 and the rubber tube 332. The two ends of the supporting wire 333 are respectively connected to the disc 31 and the smoke outlet pipe 32. The adjusting tube 33 is used to adjust the smoke outlet direction of the smoke outlet pipe 32. The supporting wire 333 in the adjusting tube 33 has a certain flexibility. By bending the adjusting tube 33, the smoke outlet direction of the smoke outlet pipe 32 can be changed to avoid the smoke from multiple smoke outlet pipes 32 from colliding with each other, which is conducive to subsequent mixing.

[0049] In some embodiments, a specific implementation of the static mixer 40 can be as follows: Figure 2 See the structure shown. Figure 2The static mixer 40 includes a main body 41 and a plurality of casings 42 sleeved on the main body 41, the plurality of casings 42 are spaced apart along the axial direction of the main body 41, the main body 41 has a plurality of mixing chambers 43 therein, the plurality of mixing chambers 43 are spaced apart along the axial direction of the main body 41, and correspond one to one with the plurality of casings 42, the mixing chamber 43 at the head end is connected with the flue gas distribution device 30, the mixing chamber 43 at the end end is connected with the denitration reactor 50, second through holes connected with the casing 42 are provided on opposite sides of each mixing chamber 43, and each casing 42 is provided with two bifurcated pipes 44 connected with adjacent mixing chambers 43, and the two bifurcated pipes 44 are arranged opposite to each other. The flue gas flowing out of the flue gas distribution device 30 enters the mixing chamber 43 at the head end of the main pipe 41, and flows out from the second through holes on both sides of the mixing chamber 43 into the casing 42, and then flows from the casing 42 into the next mixing chamber 43. The above process is repeated to realize that the flue gas continuously enters different mixing chambers 43 during its flow, which is beneficial to the full mixing of the flue gas and ensures that the temperature of the flue gas for subsequent denitrification is uniform.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A heating system for SCR denitrification in a steel rolling heating furnace, characterized in that: It comprises a smoke inlet channel, an air preheater, a smoke distribution device, a static mixer and a denitration reactor connected in sequence, a temperature regulating pipe is further provided between the smoke inlet channel and the smoke distribution device, a first mass flow controller and a spray box are sequentially provided on the temperature regulating pipe along the flow direction of the smoke, the spray box is used to atomize the reducing agent, the liquid inlet of the spray box has a fourth mass flow controller, a second mass flow controller is further provided on the smoke inlet channel, and the second mass flow controller is located between the smoke inlet of the temperature regulating pipe and the smoke inlet of the air preheater; Wherein, after the flue gas passes through the first mass flow controller and the second mass flow controller, the flue gas flow rates entering the temperature regulating pipe and the air preheater can be measured respectively, the fourth mass flow controller adjusts the amount of the reducing agent according to the amount of flue gas passing through the first mass flow controller, the flue gas temperature at the smoke inlet of the smoke inlet channel is greater than the flue gas temperature at the smoke outlet of the temperature regulating pipe, and the flue gas temperature at the smoke outlet of the temperature regulating pipe is greater than the smoke outlet temperature of the air preheater; The smoke distribution device comprises a disc and a plurality of smoke outlet pipes arranged at one axial end of the disc, a containing cavity is arranged inside the disc, and two smoke inlets are arranged on the outer circumference, one of the smoke inlets is connected to the smoke outlet side of the temperature regulating pipe, and the other of the smoke inlets is connected to the smoke outlet side of the air preheater, the axial direction of the smoke outlet pipe forms an acute angle with the axial direction of the disc, and the plurality of smoke outlet pipes are evenly distributed around the axis of the disc; An adjusting tube is also connected between the smoke outlet pipe and the disc, and the adjusting tube includes a corrugated tube located at the outer layer, a rubber tube located at the inner layer, and a supporting wire arranged between the corrugated tube and the rubber tube, and the two ends of the supporting wire are respectively connected to the disc and the smoke outlet pipe, and the adjusting tube is used to adjust the smoke outlet direction of the smoke outlet pipe; The air preheater has an air inlet and an air outlet, and an air branch pipe connecting the air inlet and the air outlet is provided outside the air preheater, and a third mass flow controller is provided at the air branch pipe and the air inlet; The two third mass flow controllers are used to adjust the amount of cold air entering the air preheater so that the smoke temperature at the smoke outlet of the air preheater is within a preset range; The static mixer includes a main body and a plurality of casings sleeved on the main body, wherein the plurality of casings are spaced apart along the axial direction of the main body, and the main body is provided with a plurality of mixing chambers, wherein the plurality of mixing chambers are spaced apart along the axial direction of the main body and correspond one to one with the plurality of casings, wherein the mixing chamber at the head end is connected with the flue gas distribution device, and the mixing chamber at the tail end is connected with the denitration reactor, and second through holes connected with the casings are provided on opposite sides of each mixing chamber, and each casing is provided with two bifurcated tubes connected with adjacent mixing chambers, and the two bifurcated tubes are arranged opposite to each other.

2. The heating system for SCR denitrification of a steel rolling heating furnace according to claim 1, characterized in that: The heating system for SCR denitrification in a steel rolling heating furnace also includes a control system, and the first mass flow controller, the second mass flow controller, the third mass flow controller and the fourth mass flow controller are all communicatively connected to the control system.

3. The heating system for SCR denitrification of a steel rolling heating furnace according to claim 1, characterized in that: The preset range is 100°C to 200°C.

4. The heating system for SCR denitrification in a steel rolling heating furnace according to claim 1, characterized in that: The spray box includes a box body, a liquid supply pipe connected to the box body, an injection body arranged between the liquid supply pipe and the box body, and an atomizing nozzle connected to the injection body and extending into the box body. The box body has an inlet and an outlet connected to the temperature control pipe, and the fourth mass flow controller is arranged on the liquid supply pipe.

5. The heating system for SCR denitrification of a steel rolling heating furnace according to claim 1, characterized in that: The temperature of the flue gas flowing out of the smoke outlet of the temperature regulating pipe is 450°C to 600°C.

6. The heating system for SCR denitrification in a steel rolling heating furnace according to claim 1, characterized in that: The temperature of the flue gas flowing out of the smoke outlet of the static mixer is 200°C to 250°C.

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