Ultralow-nitrogen fan-shaped flame heat accumulating type alternative combustion burner and control method thereof

Abstract

The invention discloses an ultralow-nitrogen fan-shaped flame heat accumulating type alternate combustion burner and a control method thereof. A burner block is arranged on the lower side of a body, a combustion channel is arranged in the burner block and communicated with a gas inlet and smoke exhaust channel, a central gas pipe with a control valve is arranged, and a central gas nozzle is arranged at the front end of the central gas pipe and communicated with the combustion channel; a first gas pipe and a second gas pipe are further arranged; a plurality of fuel outlet holes are formed in the burner block around the combustion channel and are communicated with a first gas pipe and a second gas pipe respectively, and a first gas pipe control valve and a second gas pipe control valve are arranged on the first gas pipe and the second gas pipe respectively; and the control device is electrically connected with the three gas pipe control valves respectively to control the on-off of the three gas pipe control valves. According to the burner, multiple combined combustion modes are formed through combustible gas of the center gas nozzle, the first set of gas nozzles and the second set of gas nozzles, alternate combustion is formed between the first set of gas nozzles and the second set of gas nozzles on the same burner, and the concentration of NOX generated by combustion is greatly reduced so that the NOX emission standard can be met.

Description

Technical Field

[0001] This invention relates to the field of industrial heating furnace technology, specifically to an ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner and its control method. Background Technology

[0002] Considering stringent environmental requirements and heating efficiency, industrial furnaces for heating workpieces are increasingly adopting regenerative combustion, also known as regenerative combustion industrial furnaces. Regenerative combustion industrial furnaces recover heat from flue gas through a heat storage medium in the flue. During reversal, the high-temperature heat storage medium heats the cold combustion air, enabling the combustion air to be heated from room temperature in a short time, thus utilizing the heat energy in the flue gas. Simultaneously, the hot flue gas after combustion in the furnace is exhausted through another regenerative burner, storing the sensible heat of the high-temperature flue gas in the heat storage medium of another regenerative burner. The two regenerative burners operate in alternating states of heat storage (the heat storage medium recovers heat from the flue gas) and heat release (the heat storage medium uses its heat to heat the combustion gas). In other words, the paired A-group and B-group burners in the regenerative combustion industrial furnace burn alternately, thereby achieving energy savings.

[0003] With increasingly stringent environmental protection requirements, the nitrogen oxide emission standards for regenerative combustion industrial furnaces are becoming more stringent. Therefore, existing technologies using dual-gas pipelines and multi-point combustion cannot significantly reduce NOx concentration in flue gas to meet NOx emission standards through desalination combustion. For example, CN120062625A discloses a "low-NOx combustion device for a heating furnace," which describes its technical solution as follows: "A low-NOx combustion device for a heating furnace includes a burner body. A combustion channel is provided at the upper part of the burner body. A primary combustion tube and a continuous lamp are provided inside the combustion channel. A secondary combustion tube and a secondary combustion tube burner are provided circumferentially on the outer side of the combustion channel. The secondary combustion tube burner is provided with inner and outer ring nozzles. The primary combustion tube is provided with nozzles facing the inner wall of the combustion channel." An extended primary burner tube is provided at one end of the primary burner tube near the inner wall of the combustion chamber, and the primary burner tube and the secondary burner tube are located on the same horizontal plane. The primary burner tube has a primary burner hole facing the inner edge of the end of the combustion chamber. The axial angle between the outer ring nozzle and the secondary burner tube is b1, the axial angle between the inner ring nozzle and the secondary burner tube is b2, and the angle between the conical outer wall of the combustion chamber and the secondary burner tube is c, where b2 > c > b1. A flue gas flow hole is horizontally provided on the side wall of the combustion chamber, connecting the injection area of ​​the secondary burner tube and the injection area of ​​the primary burner hole. The technical effect is that it makes full use of multi-point combustion to disperse the original concentrated combustion, providing conditions for adjusting the flame temperature. Through staged combustion and a special combustion chamber structure, flue gas recirculation combustion is realized, effectively controlling the combustion temperature, thereby effectively reducing the generation of thermal nitrogen oxides and making it easier for the flue gas emissions of small natural draft heating furnaces to meet standards. By using a special nozzle angle, the flame combustion space can be effectively controlled to adapt to small natural draft heating furnaces with a small furnace chamber, thus avoiding the phenomenon of flame burning tubes.

[0004] However, although this type of low-NOx combustion device can have its two sets of burners burning alternately, the primary combustion tube (primary burner tube) and the secondary combustion tube (secondary combustion tube burner) set on the same burner cannot form alternating combustion, and cannot truly achieve desalinated oxygen and low-NOx combustion. The concentration of NOx produced by combustion is relatively high, making it difficult to meet NOx emission standards. In addition, the use of a continuous lamp for ignition has slightly lower reliability, and the continuous lamp itself may go out, posing serious safety hazards. Furthermore, the uniformity of furnace temperature also needs to be improved. Summary of the Invention

[0005] To address the shortcomings of the existing technologies, the technical problem this invention aims to solve is: how to provide an ultra-low NOx fan-shaped flame regenerative alternating combustion burner, enabling multiple gas inlet pipes on the same burner to form alternating combustion, truly achieving desalinated oxygen and low NOx combustion, and significantly reducing the concentration of NOx produced during combustion to meet NOx emission standards; the second objective is to provide a combustion control method for industrial furnaces, enabling multiple gas inlet pipes on the same burner to form alternating combustion, significantly reducing the concentration of NOx produced during combustion to meet NOx emission standards.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: An ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner includes a body, wherein the body... The lower part is a burner brick, which has a combustion channel inside. The upper part of the body has an air intake and exhaust channel that is connected to the combustion channel. A heat storage body is installed in the air intake and exhaust channel. An ignition device is used to ignite the gas in the combustion channel. The feature is that a central gas pipe is provided, the front end of which is a central gas nozzle that is connected to the combustion channel. A central gas pipe control valve is provided on the central gas pipe. It is also equipped with a first gas pipe and a second gas pipe. On the burner brick, multiple fuel outlet holes are arranged around the combustion channel, dividing the fuel outlet holes into two groups. The first group is fully connected to the first gas pipe to form a first group of gas nozzles; the second group is fully connected to the second gas pipe to form a second group of gas nozzles. A first gas pipe control valve is installed on the first gas pipe, and a second gas pipe control valve is installed on the second gas pipe. It also includes a control device, which is electrically connected to the central gas pipe control valve, the first gas pipe control valve, and the second gas pipe control valve, respectively, and controls their on / off state by sending control signals.

[0007] Thus, the burner of the present invention forms multiple combined combustion modes through the combustible gas from the central gas nozzle, the first group of gas nozzles and the second group of gas nozzles. Moreover, the first group of gas nozzles and the second group of gas nozzles on the same burner form alternating combustion, forming true oxygen-depleted and low-nitrogen combustion, which significantly reduces the concentration of NOx produced by combustion to meet NOx emission standards.

[0008] Furthermore, the fuel outlet is arranged around the combustion channel in a concentric circle structure.

[0009] Furthermore, the first and second sets of gas nozzles are positioned to the left and right, or above and below, the central gas nozzle. These nozzles are located on opposite sides of the combustion channel diameter or its extension. This arrangement, with the first and second sets of nozzles positioned on only one side of the burner, facilitates true oxygen-depleted, low-NOx combustion, significantly reducing the NOx concentration produced during combustion to meet NOx emission standards.

[0010] Furthermore, the first gas pipe includes two parallel gas branch pipes, a first gas branch pipe and a second gas branch pipe, each equipped with a control valve to control the on / off state of the gas branch pipes. The second gas pipe includes two parallel gas branch pipes, a third gas branch pipe and a fourth gas branch pipe, each equipped with a control valve. This invention, with its first and second gas pipes each having two fuel branch pipes for separate control, allows for more diverse gas supply methods, facilitates accurate metering of the gas volume entering the pipeline, provides more precise control, and facilitates alternating combustion.

[0011] Furthermore, after the two gas branch pipes (one and two) merge, they are connected to or form a first gas pipe, which is then connected to the corresponding fuel outlet; after the two gas branch pipes (three and four) merge, they are connected to or form a second gas pipe, which is then connected to the corresponding fuel outlet.

[0012] Furthermore, the incomplete combustion region of the first set of gas nozzles and the incomplete combustion region of the second set of gas nozzles are both fan-shaped regions.

[0013] The incomplete combustion regions of the first group of nozzles and the second group of nozzles are both fan-shaped regions no larger than 240º. A regenerative combustion furnace includes a pair of burners arranged in a specific configuration, characterized in that the burners are as described above.

[0014] A control method for an ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner, characterized by the following steps: 1) In the low-temperature stage of the combustion furnace used with burners, where there is no ignition, the control device... When the central gas pipe control valve is opened, fuel is introduced, and combustion air is introduced from the intake and exhaust channels. The fuel and air mix around the central gas nozzle and are ignited by the ignition device. 2) After ignition, open the first gas pipe control valve and the second gas pipe control valve to open the first gas pipe and the second gas pipe. The central gas pipe, the first gas pipe and the second gas pipe are used to input fuel. The central gas nozzle, the first group of gas nozzles and the second group of gas nozzles are all ignited and burned to heat the furnace. Assuming the combustion furnace requires 1 unit of fuel, then the distribution coefficient of the fuel supplied through the three gas pipes is... As shown below, the central gas pipe is a, the first gas pipe is b, and the second gas pipe is c. Then a + b + c = 1, and a, b, and c are all values ​​greater than zero and less than 1. 3) After heating to the first set temperature, the central gas pipe and the first gas pipe, or the central gas pipe and the second gas pipe, are used for alternating combustion through the control device; then the fuel distribution coefficients of the three gas pipes are a for the central gas pipe, b for the first gas pipe, and c for the second gas pipe. When only the central gas pipe and the first gas pipe are supplied with gas for combustion, then a+b=1; when only the central gas pipe and the second gas pipe are supplied with gas for combustion, then a+c=1. 4) After heating to the second set temperature, the central gas pipe is shut off by the control device to stop the fuel input. The first gas pipe and the second gas pipe are used to alternately input fuel, and the first set of gas nozzles and the second set of gas nozzles are used to alternate combustion. In this situation, when gas is supplied to the first gas pipe for combustion, b=1, or b is a set value that is less than 1 and greater than zero; when gas is supplied to the second gas pipe for combustion, c=1, or c is a set value that is less than 1 and greater than zero.

[0015] Furthermore, the first gas pipe is equipped with two parallel gas branch pipes, namely a first gas branch pipe and a second gas branch pipe, and the second gas pipe is equipped with two parallel gas branch pipes, namely a third gas branch pipe and a fourth gas branch pipe. Let the fuel distribution coefficient of the first gas branch pipe be b1, the distribution coefficient of the second gas branch pipe be b2, the distribution coefficient of the third gas branch pipe be c1, and the distribution coefficient of the fourth gas branch pipe be c2. When fuel is simultaneously supplied and burned by the central gas pipe, the first gas branch pipe, and the third gas branch pipe, then a + b1 + c1 = 1; or when fuel is simultaneously supplied and burned by the central gas pipe, the second gas branch pipe, and the fourth gas branch pipe. When a + b2 + c2 = 1, then a + b2 = 1; or when the central gas pipe and the gas branch pipe simultaneously supply fuel for combustion, then a + b2 = 1; or when the central gas pipe and the gas branch pipe simultaneously supply fuel for combustion, then a + c2 = 1; or when only the two gas branch pipes and the gas branch pipe of the first gas pipe simultaneously supply fuel for combustion, then b1 + b2 = 1; or when only the gas branch pipes and the gas branch pipe of the second gas pipe simultaneously supply fuel for combustion, then c1 + c2 = 1; b1, b2, c1, and c2 are all set values ​​that are less than 1 and greater than zero.

[0016] In summary, the beneficial effects of the present invention are as follows: 1. The ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner of the present invention has a central gas nozzle on the burner, and a first group of gas nozzles and a second group of gas nozzles are respectively arranged on both sides of the central gas nozzle. In the low temperature stage, the combustible gas in the central gas nozzle is ignited by an ignition device, and it can burn together with the combustible gases in the first group of gas nozzles and the second group of gas nozzles to heat the furnace. After the temperature rises to a first set temperature, the combustible gas in the central gas nozzle can burn separately with the combustible gas in the first group of gas nozzles, or the combustible gas in the central gas nozzle can burn separately with the combustible gas in the second group of gas nozzles, forming alternating combustion between the first group of gas nozzles and the second group of gas nozzles. After the temperature rises to a second set temperature, the input of combustible gas in the central gas nozzle stops, and the combustible gas in the first group of gas nozzles or the combustible gas in the second group of gas nozzles burns separately, forming alternating combustion between the first group of gas nozzles and the second group of gas nozzles.

[0017] Tests have shown that this alternating combustion mode of the present invention can achieve ultra-low nitrogen oxide emissions. Current local NOx emission standards have a minimum of 100 mg / L, but the alternating combustion mode of the present invention can reduce NOx emissions to below 50 mg / L, demonstrating excellent NOx reduction effects.

[0018] 2. In this invention, under the control of a reversing valve and other control devices, the combustible gas from the central gas nozzle burns together with the combustible gases from the first group of gas nozzles and the second group of gas nozzles, or burns alternately, forming true oxygen-depleted and low-nitrogen combustion, which significantly reduces the concentration of NOx produced by combustion to meet NOx emission standards.

[0019] 3. The combustion control method of the industrial furnace of the present invention enables multiple gas inlet pipes set on the same burner to form alternating combustion, thereby greatly reducing the NOx concentration generated by combustion to meet the NOx emission standards.

[0020] 4. The central gas pipeline of the present invention, with its central gas nozzle at the front end, in conjunction with an ignition device, can be safely and reliably ignited at low temperatures. The flame of the central gas nozzle can also ignite the fuel from the first set of gas nozzles in the first gas pipeline and the fuel from the second set of gas nozzles in the second gas pipeline in a timely and effective manner, ensuring that the gas can be safely and reliably ignited and improving the reliability and safety of combustion in industrial furnaces.

[0021] 5. The industrial furnace of the present invention can improve the uniformity of furnace temperature. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of the ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner structure of the present invention; Figure 2 yes Figure 1Sectional view along AA; Figure 3 yes Figure 1 View along direction B; Figure 4 This is a schematic diagram of the structure of the second embodiment of the present invention; Figure 5 A schematic diagram of the incomplete combustion zone formed by the combustion of the first set of nozzles; Figure 6 This is a schematic diagram of the incomplete combustion zone formed by the combustion of the second set of nozzles.

[0023] 1—Body, 2—Burner brick, 3—Combustion channel, 4—Intake and exhaust channel, 5—Heat storage body, 6—Blowbox, 7—Central gas pipe, 8—Central gas nozzle, 9—Central gas pipe control valve, 10—Ignition device, 11—Flame monitoring device, 14—First gas pipe, 15—First group of gas nozzles, 16—First gas pipe control valve, 17—Second gas pipe, 18—Second group of gas nozzles, 19—Second gas pipe control valve, 20—Control device, 21—Fuel outlet, 100—Incomplete combustion area of ​​the first group of nozzles, 101—Incomplete combustion area of ​​the second group of nozzles, 141—Gas branch pipe 1, 142—Gas branch pipe 2, 143—Gas branch pipe 1 control valve, 144—Gas branch pipe 2 control valve, 145—Gas branch pipe 3, 146—Gas branch pipe 4, 147—Gas branch pipe 3 control valve, 148—Gas branch pipe 4 control valve. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0025] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product is in use. They are only for the convenience of describing the 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 the invention. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In addition, the terms "horizontal," "vertical," etc., do not indicate that the component is required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] Example: like Figure 1 , 2 As shown in Figure 3, the ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner of the present invention includes a body 1, a burner brick 2 on the lower side of the body 1, a combustion channel 3 inside the burner brick 2, and an air intake and exhaust channel 4 on the upper part of the body 1, within which a heat storage body 5 is installed. The air intake and exhaust channel 4 serves as the inlet channel for combustion air and the outlet channel for flue gas in the regenerative alternating combustion, and it is connected to the combustion channel 3. The end of the combustion channel 3 facing the furnace is usually shaped like a funnel to facilitate the formation of a flat flame combustion state on the surface of the burner brick 2 after combustion. Some industrial furnaces have a bellows 6 installed at the upper end of the air intake and exhaust channel 4, through which combustion air enters the air intake and exhaust channel 4. The above is prior art and will not be further described here.

[0027] The ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner of the present invention is provided with a central gas pipe 7, the front end of which is a central gas nozzle 8 connected to a combustion channel 3. The fuel input from the central gas pipe 7 is mixed with the combustion air introduced from the intake and exhaust channels 4 in the combustion channel 3. The ignition device 10 ignites the gas in the combustion channel 3. Its front end extends into the combustion channel 3, close to the central gas nozzle 8. Under the action of the ignition spark of the ignition device 10, the combustible gas is ignited in time. A central gas pipe control valve 9 is provided on the central gas pipe 7. The central gas pipe control valve 9 is electrically connected to a control device 20. Under the control of the control device 20, the on / off (open or close) of the central gas pipe control valve 9 and the opening degree are controlled to control the volume of combustible gas passing through the central gas pipe 7 to meet the requirements of the combustion process. The central gas nozzle 8 is usually located in the middle of the burner brick 2. A flame monitoring device 11 is installed in the combustion channel 3 or near the central gas nozzle 8 to monitor whether the fuel sprayed from the central gas nozzle 8 is ignited, that is, whether there is a flame in the combustion channel 3.

[0028] A first gas pipe 14 and a second gas pipe 17 are also provided. On the burner brick 2, multiple fuel outlet holes 21 are arranged around the combustion channel 3. These fuel outlet holes 21 are divided into two groups. The first group is fully connected to the first gas pipe 14 to form the first group of gas nozzles 15. The second group is fully connected to the second gas pipe 17 to form the second group of gas nozzles 18. The first group of gas nozzles 15 and the second group of gas nozzles 18 are respectively located on both sides of the diameter or the diameter extension line of the combustion channel 3. The fuel input into the first gas pipe 14 is sprayed out through the first group of gas nozzles 15 (sprayed out through the multiple fuel outlet holes 21). A first gas pipe control valve 16 is provided on the first gas pipe 14. The first gas pipe control valve 16 is electrically connected to the control device 20. Under the control of the control device 20, the opening or closing of the first gas pipe control valve 16 and the opening degree are controlled to control the volume of combustible gas passing through the first gas pipe 14 to meet the requirements of the combustion process. The fuel input through the second gas pipe 17 is ejected from the second set of gas nozzles 18. A second gas pipe control valve 19 is installed on the second gas pipe 17. The second gas pipe control valve 19 is electrically connected to the control device 20. Under the control of the control device 20, the opening or closing of the second gas pipe control valve 19 and the degree of opening are controlled to control the volume of combustible gas passing through the second gas pipe 19 and meet the requirements of the combustion process.

[0029] The number of the first group of gas nozzles 15 and the second group of gas nozzles 18 is determined according to process requirements, such as 2, 3, 4, 5, 6, 7, 8, etc. They are usually arranged around the combustion channel 3, and the figure shows a concentric circle structure. The distance between them and the combustion channel 3 should first take into account the need for reliable ignition of fuel. The fuel sprayed from the first group of gas nozzles 15 and the second group of gas nozzles 18 should be ignited by the flame formed after the fuel in the central gas nozzle 8 is ignited.

[0030] The ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner of the present invention has a central gas nozzle 8 on the burner (burner brick 2), and a first group of gas nozzles 15 and a second group of gas nozzles 18 on both sides of the central gas nozzle 8. During the low-temperature stage, the combustible gas in the central gas nozzle 8 is ignited by an ignition device, which in turn ignites the fuel ejected from the first group of gas nozzles 15 and the second group of gas nozzles 18. During this stage, the fuel from the central gas nozzle 8 and the first and second groups of gas nozzles 15 and 18 burn together to heat the furnace. After the temperature rises to a first set temperature, the control device 20 activates, and the central gas nozzle... The combustible gas of 8 can be burned separately with the fuel of the first set of gas nozzles 15, or the combustible gas of the central gas nozzle 8 and the combustible fuel of the second set of gas nozzles 18, thus forming alternating combustion between the first set of gas nozzles 15 and the second set of gas nozzles 18; after the temperature rises to the second set temperature, the control device 20 is activated, the fuel input of the central gas pipe 7 is stopped, and fuel is introduced through the first gas pipe 14 or the second gas pipe 17, so that the first set of gas nozzles 15 or the second set of gas nozzles 18 burns alone, forming alternating combustion between the first set of gas nozzles 15 and the second set of gas nozzles 18.

[0031] For ease of control and accurate metering of fuel, the first gas pipe 14 includes two parallel gas branch pipes 141 and 142. Correspondingly, a gas branch pipe control valve 143 and a gas branch pipe control valve 144 are respectively installed on the gas branch pipes 141 and 142 to control the on / off state of the gas branch pipes 141 and 142. The two gas branch pipes 141 and 142 merge and then enter the first gas pipe 14, or form the first gas pipe 14 and then enter the corresponding fuel outlet 21. In this way, fuel with different flow rates (volumes) can be input into the gas branch pipes 141 and 142, which facilitates the further realization of the alternating combustion of the present invention. The second gas pipe 17 includes two parallel gas branch pipes 145 and 146. Correspondingly, gas branch pipe control valves 147 and 148 are respectively installed on the gas branch pipes 145 and 146 to control the on / off state of the gas branch pipes 145 and 146. The two gas branch pipes 145 and 146 merge and then enter the second gas pipe 17, or form the second gas pipe 17 and then enter the corresponding fuel outlet 21. In this way, fuel with different flow rates (volumes) can be input into the gas branch pipes 145 and 146, which facilitates the further realization of the alternating combustion of the present invention. Accordingly, the first gas pipe control valve 16 may be a control valve that is set separately on the first gas pipe 14, or it may refer to the gas branch control valve 143 and the gas branch control valve 144; the second gas pipe control valve 19 may be a control valve that is set separately on the second gas pipe 17, or it may refer to the gas branch control valve 147 and the gas branch control valve 148.

[0032] The control device 20 of the present invention is electrically connected to components such as the central gas pipe control valve 9, the first gas pipe control valve 16, the second gas pipe control valve 19, the gas branch pipe control valve 143, the gas branch pipe control valve 144, the gas branch pipe control valve 147, the gas branch pipe control valve 148, and the flame monitoring device 11. It is controlled by sending control signals. This can be achieved using existing technology and will not be further described here.

[0033] like Figure 3 , 4As shown, the first group of gas nozzles 15 and the second group of gas nozzles 18 of the present invention correspond to the fuel outlet holes 21 provided on the burner brick 2, and each nozzle of the first group of gas nozzles 15 and the second group of gas nozzles 18 corresponds to a fuel outlet hole 21. The fuel input from the first gas pipe 14 and the second gas pipe 17 is ejected from the fuel outlet hole 21. The first group of gas nozzles 15 and the second group of gas nozzles 18 can be arranged on the left and right sides or the upper and lower sides of the central gas nozzle 8, and are arranged circumferentially around the central gas nozzle 8. The first group of gas nozzles 15 and the second group of gas nozzles 18 are respectively located on both sides of the diameter or the extension line of the diameter of the combustion channel 3, that is, each is arranged on one side.

[0034] like Figure 5 , 6 As shown, when the first and second groups of gas nozzles of this invention burn alternately, the incomplete combustion area 100 generated by the combustion of the first group of gas nozzles and the incomplete combustion area 101 generated by the combustion of the second group of gas nozzles are both fan-shaped areas, as shown in the figure. The first and second groups of nozzles are located on the left and right sides of the figure, respectively. The air supply of the flat flame burner of this invention enters the outlet of the combustion channel 3 through the air intake and exhaust channel 4, adheres to the furnace wall, and diffuses 360° inside the furnace. The air supply volume is basically constant. The incomplete combustion area 100 of the first group of nozzles and the incomplete combustion area 101 generated by the combustion of the second group of gas nozzles are fan-shaped areas no larger than 240º, and are usually fan-shaped areas below 180º.

[0035] When the combustion is switched to the first set of gas nozzles on the left, the first gas pipe control valve 16 of the first gas pipe 14 opens, supplying 100% (i.e., the total amount 1) of fuel (such as natural gas) to the left side. However, the amount of air flowing into the gas supply area is only <50%, resulting in an oxygen-deficient state on the left side and forming an incomplete combustion flame area. The flame temperature of the incomplete combustion is relatively low, and the NOx generation is very low. At this time, the unburned air in the area on the right side of the burner mixes with the furnace gas with an oxygen content of only about 3%, forming a low-oxygen state. The maximum oxygen content = (21% (air oxygen content) + furnace gas oxygen content) / 2. Taking a furnace gas oxygen content of 3% as an example, the oxygen content of the low-oxygen gas in the furnace is only about 12%, far lower than the 21% oxygen content of the combustion air. According to the HTAC theory of high-temperature air combustion technology, fuel can be completely burned in a low-oxygen environment with an oxygen content of only 3%. Low-oxygen combustion inhibits the formation of thermal NOx, resulting in extremely low NOx emissions. The excess fuel gas on the left side is mixed with the low-oxygen furnace gas in the furnace and burned completely before being discharged by the regenerative burner in the flue gas extraction state.

[0036] Similarly, when the combustion is switched to the second set of nozzles on the right, similar to the isolated combustion on the left, an incomplete combustion zone is formed. The right-side zone is in an oxygen-deficient state, forming an incomplete combustion flame zone. The flame temperature of the incomplete combustion is relatively low, resulting in very low NOx formation. According to the High Temperature Air Combustion (HTAC) theory, fuel can burn completely in a low-oxygen environment with an oxygen content of only 3%. Low-oxygen combustion inhibits the formation of thermal NOx, resulting in extremely low NOx emissions.

[0037] This invention creatively utilizes the air distribution characteristics of a flat flame burner to divide the fuel supply of the same burner into a first pipe and a second pipe, supplying fuel from both sides. Through alternating combustion at nozzles independently set on both sides, low-oxygen combustion suppresses the formation of thermal NOx, resulting in extremely low NOx emissions and achieving low nitrogen emissions in the furnace gas. In addition, alternating combustion makes the energy supply more uniform and the furnace temperature more uniform.

[0038] A regenerative combustion furnace includes a plurality of burners arranged in pairs, characterized in that the burners are as described above.

[0039] The control method for the ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner of the present invention is typically set within a control device 20 through a control program. The control device 20 controls the operation of the entire burner (combustion furnace), including the central gas pipe control valve 9, the first gas pipe control valve 16, and the second gas pipe control valve 19, to achieve the objective of the present invention. It includes the following steps: 1. In the low-temperature stage when the combustion furnace used with the burner is not ignited, the central gas pipe control valve 9 is opened by the control device 20 to introduce fuel. Combustion air is introduced from the intake and exhaust channels 4. The fuel and air mix around the central gas nozzle 8 and are ignited by the ignition device 10. 2. After ignition, the first gas pipe control valve 16 and the second gas pipe control valve 19 are opened by the control device 20, so that the first gas pipe 14 and the second gas pipe 17 are opened, so that the central gas pipe 7, the first gas pipe 14 and the second gas pipe 17 are fed together, and the central gas nozzle 8, the first group of gas nozzles 15 and the second group of gas nozzles 18 are all ignited and burned to heat the furnace. Assuming that the combustion furnace requires 1 unit of fuel during this heating phase, The fuel distribution coefficients for the three gas pipes are as follows: a for the central gas pipe 7, b for the first gas pipe 14, and c for the second gas pipe 17. Therefore, a + b + c = 1, where a, b, and c are all values ​​greater than zero and less than 1. b and c can be equal or different. Considering the safety of combustion ignition, since the fuel in the central gas pipe 7 is used to ignite the fuel in the nozzles of the first and second gas pipes 14, a is usually not less than 0.3. If a is 0.3, then b and c can be equal, at 0.35. Of course, b and c can also be different and unequal, such as b being 0.3 and c being 0.4. If a is 0.4, then b and c can be equal, at 0.3. Of course, b and c can also be different and unequal, such as b being 0.28 and c being 0.32. 3. After heating to the first set temperature, such as 800℃-1000℃, the control device 20 can use the central gas pipe 7 and the first gas pipe 14 to simultaneously input fuel for combustion, or the central gas pipe 7 and the second gas pipe 17 to simultaneously input fuel for combustion in an alternating combustion mode; then the distribution of fuel entering the three gas pipes is as follows: central gas pipe 7 is a, first gas pipe 14 is b, and second gas pipe 17 is c, where a, b, and c are all values ​​greater than zero and less than 1; When only the central gas pipe 7 and the first gas pipe 14 are supplied with gas for combustion, then a+b=1. If a is 0.3, then b is 0.7; or if a is 0.4, then b is 0.6, etc. When the combustion alternates between the central gas pipe 7 and the second gas pipe 17, then a+c=1. If a is 0.3, then c is 0.7; or if a is 0.4, then c is 0.6, etc. In this situation, the central gas pipe 7 is continuously supplied with fuel for combustion, the first gas pipe 14 and the second gas pipe 17 are supplied with fuel alternately, and the first set of gas nozzles 15 and the second set of gas nozzles 18 on both sides of the central gas nozzle 8 are alternately supplied with fuel for combustion. 4. After heating to the second set temperature, such as 1000℃ or above, the central gas pipe 7 is closed by the control device 20 to stop the fuel input. The first gas pipe 14 and the second gas pipe 17 alternately input fuel, and the first group of gas nozzles 15 and the second group of gas nozzles 18 alternately burn fuel. During this stage, the furnace temperature is relatively high, usually in the later stage of heating or the furnace insulation stage. The fuel input through the first gas pipe 14 and the second gas pipe 17 can be automatically ignited and burned, basically without the need for the flame of the central gas nozzle 8 to ignite it. In this situation, when gas is introduced into the first gas pipe 14 for combustion, b=1. Of course, if the heating process considers reducing the amount of fuel input during this stage, b is a set value that is less than 1 and greater than zero. When gas is introduced into the second gas pipe 17 for combustion, c=1. Of course, if the heating process considers reducing the amount of fuel input during this stage, c is a set value that is less than 1 and greater than zero.

[0040] Thus, the ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner of the present invention can produce a variety of alternating combustion states. In addition to the A and B burners burning in turn for regenerative combustion, a variety of alternating combustion states can also be formed inside the same burner.

[0041] Two parallel gas branch pipes 141 and 142 are installed in the first gas pipe 14, and two parallel gas branch pipes 145 and 146 are installed in the second gas pipe 17. By introducing fuel at different flow rates (volumes) into the gas branch pipes 141, 142, 145, and 146, and assuming the fuel distribution coefficients for gas branch pipes 141, 142, 145, and 146 are b1, b2, c1, and c2 respectively, various combined fuel delivery methods can be achieved. b1, b2, c1, and c2 are all values ​​greater than zero and less than 1. At different combustion stages, corresponding control valves are opened according to process requirements to obtain various combined alternating combustion methods. When the central gas pipe 7, gas branch pipe 141, and gas branch pipe 145 simultaneously deliver fuel for combustion, a+b 1+c1=1; or when the central gas pipe 7, gas branch pipe 142, and gas branch pipe 146 simultaneously supply fuel for combustion, then a+b2+c2=1; or when the central gas pipe 7 and gas branch pipe 142 simultaneously supply fuel for combustion, then a+b2=1; or when the central gas pipe 7 and gas branch pipe 146 simultaneously supply fuel for combustion, then a+c2=1; or when only the two gas branch pipes 141 and 142 of the first gas pipe 14 simultaneously supply fuel for combustion, then b1+b2=1; or when only the gas branch pipes 145 and 146 of the second gas pipe 17 simultaneously supply fuel for combustion, then c1+c2=1, etc. Alternating combustion can be achieved through various combinations, and the amount of fuel supplied is very accurate, facilitating metering and automatic control; b1, b2, c1, and c2 are all set values ​​less than 1 and greater than zero, specifically determined by the combustion process of the combustion furnace.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described with reference to preferred embodiments, those skilled in the art should understand that various changes in form and detail can be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. An ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner, comprising a body (1), wherein the body (1) The lower side is a burner brick (2), and a combustion channel (3) is provided inside the burner brick (2). An air intake and exhaust channel (4) is provided on the upper part of the body (1) and is connected to the combustion channel (3). A heat storage body (5) is provided inside the air intake and exhaust channel (4). An ignition device (10) is used to ignite the gas in the combustion channel (3); characterized in that, A central gas pipe (7) is provided, with a central gas nozzle (8) at its front end connected to the combustion channel (3). A central gas pipe control valve (9) is provided on the central gas pipe (7). A first gas pipe (14) and a second gas pipe (17) are also provided. On the burner brick (2), multiple fuel outlet holes (21) are arranged around the combustion channel (3), dividing the fuel outlet holes (21) into two groups. The first group is fully connected to the first gas pipe (14) to form the first group of gas nozzles (15); the second group is fully connected to the second gas pipe (17) to form the second group of gas nozzles (18). A first gas pipe control valve (16) is set on the first gas pipe (14), and a second gas pipe control valve (19) is set on the second gas pipe (17). It also includes a control device (20), which is electrically connected to the central gas pipe control valve (9), the first gas pipe control valve (16), and the second gas pipe control valve (19) respectively, and controls their on / off state by sending control signals.

2. The ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner according to claim 1, characterized in that, The fuel outlet (21) is arranged around the combustion channel (3) and has a concentric circle structure.

3. The ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner according to claim 1 or 2, characterized in that, The first group of gas nozzles (15) and the second group of gas nozzles (18) are located on the left and right sides, or the upper and lower sides of the central gas nozzle (8). The first group of gas nozzles (15) and the second group of gas nozzles (18) are located on both sides of the diameter or the extension line of the combustion channel (3).

4. The ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner according to any one of claims 1-3, characterized in that, The first gas pipe (14) includes two parallel gas branch pipes (141) and gas branch pipe (142), with gas branch pipe (141) and gas branch pipe (142) respectively equipped with gas branch pipe (143) and gas branch pipe (144) to control the on / off state of gas branch pipe (141) and gas branch pipe (142); the second gas pipe (17) includes two parallel gas branch pipes (145) and gas branch pipe (146), with gas branch pipe (145) and gas branch pipe (146) respectively equipped with gas branch pipe (147) and gas branch pipe (148).

5. The ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner according to claim 4, characterized in that, Two gas branch pipes (141) and two gas branch pipes (142) merge and are connected to or form a first gas pipe (14), and then connected to the corresponding fuel outlet (20); two gas branch pipes (145) and two gas branch pipes (146) merge and are connected to or form a second gas pipe (17), and then connected to the corresponding fuel outlet (21).

6. The ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner according to any one of claims 1-3, characterized in that, The incomplete combustion area (100) of the first group of gas nozzles (15) and the incomplete combustion area (101) of the second group of gas nozzles (16) are both fan-shaped areas no larger than 240º.

7. A regenerative combustion furnace, comprising a plurality of burners arranged in pairs, characterized in that, The burner is as described in any one of claims 1-6.

8. A control method for an ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner, characterized in that... Includes the following steps, 1) During the low-temperature stage when the combustion furnace used with the burner is not ignited, the control device (20) is activated. Fuel is introduced by opening the central gas pipe control valve (9), and combustion air is introduced from the intake and exhaust passage (4). The fuel and air mix around the central gas nozzle (8) and are ignited by the ignition device (10). After ignition, open the first gas pipe control valve (16) and the second gas pipe control valve (19) to allow... The first gas pipe (14) and the second gas pipe (17) are opened, and the central gas pipe (7), the first gas pipe (14) and the second gas pipe (17) are fed together with fuel. The central gas nozzle (8), the first group of gas nozzles (15) and the second group of gas nozzles (18) are all ignited and burned to heat the furnace. Assuming the combustion furnace requires 1 unit of fuel, the fuel distribution coefficients from the three gas pipes are as follows: (Center) If gas pipe (7) is a, first gas pipe (14) is b, and second gas pipe (17) is c, then a+b+c=1, and a, b, and c are all values ​​greater than zero and less than 1. After heating to the first set temperature, the central gas pipe (7) is used by the control device (20) to... The first gas pipe (14), or the central gas pipe (7) and the second gas pipe (17) are alternately burned; then the distribution coefficient of the fuel introduced into the three gas pipes is a for the central gas pipe (7), b for the first gas pipe (14), and c for the second gas pipe (17); When only the central gas pipe (7) and the first gas pipe (14) are supplied with gas for combustion, then a+b=1; when only the central gas pipe (7) and the second gas pipe (17) are supplied with gas for combustion, then a+c=1. 4) After heating to the second set temperature, the central gas pipe (7) is closed by the control device (20) to stop the fuel input. The first gas pipe (14) and the second gas pipe (17) are used to alternately input fuel, and the first set of gas nozzles (15) and the second set of gas nozzles (18) are used to alternate combustion. In this situation, when the first gas pipe (14) is supplied with gas for combustion, b=1, or b is a set value that is less than 1 and greater than zero; when the second gas pipe (17) is supplied with gas for combustion, c=1, or c is a set value that is less than 1 and greater than zero.

9. The control method for the ultra-low nitrogen fan-shaped flame regenerative alternating combustion burner according to claim 8, characterized in that, Two parallel gas branch pipes (141 and 142) are installed in the first gas pipe (14), and two parallel gas branch pipes (145 and 146) are installed in the second gas pipe (17). Let the fuel distribution coefficient of the gas branch pipe (141) be b1, the distribution coefficient of the gas branch pipe (142) be b2, the distribution coefficient of the gas branch pipe (145) be c1, and the distribution coefficient of the gas branch pipe (146) be c2. When the central gas pipe (7), the gas branch pipe (141) and the gas branch pipe (145) simultaneously supply fuel for combustion, then a+b1+c1=1; or the central gas pipe (7), the gas branch pipe (142) and the gas branch pipe (146) (146) When fuel is supplied and burned simultaneously, a+b2+c2=1; or when fuel is supplied and burned simultaneously through the central gas pipe (7) and the gas branch pipe (142), a+b2=1; or when fuel is supplied and burned simultaneously through the central gas pipe (7) and the gas branch pipe (146), a+c2=1; or when fuel is supplied and burned simultaneously through the two gas branch pipes (141) and the gas branch pipe (142) of the first gas pipe (14), b1+b2=1; or when fuel is supplied and burned simultaneously through the gas branch pipe (145) and the gas branch pipe (146) of the second gas pipe (17), c1+c2=1; b1, b2, c1, and c2 are all set values ​​that are less than 1 and greater than zero.

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