Regenerative ammonia burner and combustion system

Abstract

The present application relates to the field of combustion equipment, disclose a kind of regenerative ammonia combustor and combustion system, wherein, regenerative ammonia combustor includes: regenerative box, inside is provided with regenerative flow passage, regenerative flow passage is filled with regenerator, regenerative box outside is provided with exhaust gas interface and combustion gas interface;Combustion shell, inside is provided with transfer chamber and gas outlet flow passage, transfer chamber is close to the end of gas outlet flow passage and is provided with shunt groove, the end of transfer chamber away from gas outlet flow passage is provided with inlet pipe, inlet pipe extends to shunt groove, multiple premix flow passages are arranged between transfer chamber and gas outlet flow passage in combustion shell, multiple premix flow passages and the side wall between shunt groove are respectively provided with communication hole, gas flow passage is arranged between the side of transfer chamber and the other end of regenerative flow passage in combustion shell;Ignition denitration integrated gun is inserted into gas outlet flow passage, the present application can improve the ignition and combustion stability of ammonia, and reduce the emission of ammonia, nitrogen oxides and other pollutants while recycling flue gas waste heat.

Description

Technical Field

[0001] This invention relates to the field of combustion equipment and discloses a regenerative ammonia burner and combustion system. Background Technology

[0002] Ammonia is considered an important alternative fuel for achieving carbon neutrality globally because its combustion products do not contain carbon dioxide and its storage and transportation technologies are mature. However, ammonia's low calorific value, high ignition energy, low flame propagation speed, narrow flammability limit, and high nitrogen oxide emissions restrict its application and development in the industrial sector. Furthermore, the heat generated by ammonia combustion is not fully utilized, resulting in energy waste. Therefore, there is an urgent need for a burner that can achieve stable and efficient ammonia combustion, improving the utilization rate of the heat generated by ammonia combustion while reducing emissions of pollutants such as nitrogen oxides and residual ammonia. Summary of the Invention

[0003] The purpose of this invention is to provide a regenerative ammonia burner and combustion system to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.

[0004] According to a first aspect of the present invention, a regenerative ammonia burner includes: a heat storage box having a heat storage channel inside, the heat storage channel being filled with a heat storage body, and a three-way reversing valve having a flue gas outlet and a combustion-supporting gas outlet at one end of the outer side of the heat storage box near the heat storage channel; a combustion shell having a transfer chamber and an outlet gas channel separated from each other inside, the outlet gas channel extending away from the transfer chamber to one side of the combustion shell, and a diversion groove being provided at one end of the transfer chamber near the outlet gas channel. An air inlet pipe is provided at the end of the cavity away from the outlet air passage, and the air inlet pipe extends to the diversion groove. Multiple premixed flow channels are arranged inside the combustion shell between the transfer cavity and the outlet air passage. The multiple premixed flow channels are arranged around the diversion groove. A communication hole is provided between the multiple premixed flow channels and the side wall of the diversion groove. The combustion shell is connected to the outside of the heat storage box. An airflow channel is provided inside the combustion shell between one side of the transfer cavity and the other end of the heat storage flow channel. The ignition and denitrification integrated gun is inserted into the outlet air passage.

[0005] This technical solution has at least the following beneficial effects: The regenerative ammonia burner has two working states: combustion and flue gas exhaust. When used as a flue gas exhaust system, the exhaust port is connected to the regenerative flow channel. At this time, an external heating furnace, such as a kiln or casting furnace, is connected from the exhaust flow channel. After the flue gas enters the exhaust flow channel, the ignition and denitrification integrated gun sprays ammonia gas. The ammonia flow rate is adjusted in real time according to the detected nitrogen oxide emission concentration, and the ratio of ammonia to compressed air is controlled to be below the combustible range. The injected ammonia gas undergoes selective non-catalytic reduction with the nitrogen oxides in the flue gas. It mixes as it flows through the premixing channel, further improving the reaction efficiency. Some nitrogen oxides are reduced to nitrogen and water, which together enter the regenerative flow channel from the transfer chamber and airflow channel. After exchanging heat with the heat storage medium in the regenerative flow channel, they are discharged from the exhaust port. At this time, the heat storage medium effectively recovers the heat from the flue gas. When used as a combustion system, a three-way reversing valve switches the connection between the combustion-supporting gas port and the regenerative flow channel. Combustion-supporting gas is supplied from the combustion-supporting gas port and flows through the regenerative flow channel. The hot body is heated by a heat storage medium. When it reaches the transfer chamber from the airflow channel, it becomes a high-temperature combustion-supporting gas. The inlet pipe connects to an external ammonia source. The ammonia supplied through the inlet pipe enters the distribution tank and then the premixing channel through the connecting hole. Inside the transfer chamber, the high-temperature combustion-supporting gas enters the outlet airflow channel from the premixing channel, where it mixes rapidly and evenly with the ammonia. Some of the ammonia is decomposed into hydrogen at high temperature, which also supports combustion. The mixture entering the outlet airflow channel is ignited by the integrated ignition and denitrification gun, resulting in a violent combustion reaction and a large fire. The flame generates high-temperature flue gas, which supplies heat to the interior of the heating furnace. In this way, the waste heat of the combustion flue gas is collected and utilized to heat the heat storage body during the exhaust state. During the combustion state, the combustion-supporting gas flows through the heated heat storage body, which significantly reduces the heat loss of the exhaust flue gas and improves the overall thermal efficiency. At the same time, it can significantly broaden the combustible range of ammonia and reduce the difficulty of ammonia ignition. In addition, the premixed flow channel can enhance the mixing of air and fuel and prolong the residence time, while causing some ammonia to be decomposed at high temperature, which helps to stabilize the ignition and combustion of ammonia.

[0006] According to some embodiments of the present invention, the premixed flow channel extends obliquely from the transfer chamber to the outlet flow channel in a direction offset from the axis of the outlet flow channel.

[0007] According to some embodiments of the present invention, the premixed flow channel includes a narrowing section and a mixing section connected to each other. The inner diameter of the narrowing section gradually decreases along the direction close to the mixing section. The narrowing section is connected to the transfer cavity. The mixing section is provided with a plurality of the connecting holes along its extension direction. The mixing section is connected to the outlet flow channel.

[0008] According to some embodiments of the present invention, the air outlet duct is provided with a contraction section, the inner diameter of which gradually decreases in the direction away from the heat storage box.

[0009] According to some embodiments of the present invention, a cooling sleeve is provided on the outer side of the air intake pipe, an airflow gap is formed between the inner wall of the cooling sleeve and the outer wall of the air intake pipe, the airflow gap is connected to the diversion groove, and one end of the cooling sleeve extends out of the heat storage box and is connected to a cold air pipe.

[0010] According to some embodiments of the present invention, the heat storage channel includes a first heat storage section, a second heat storage section, a denitrification section and a third heat storage section connected in sequence, and the heat storage body includes a phase change heat storage element filled in the first heat storage section, a denitrification catalyst filled in the denitrification section, a first ceramic heat storage element filled in the second heat storage section and a second ceramic heat storage element filled in the third heat storage section.

[0011] According to some embodiments of the present invention, a downwardly extending partition is provided on the top side of the heat storage tank. A first heat storage section is formed between one side of the partition and the heat storage tank, and a second heat storage section, a denitrification section, and a third heat storage section are formed between the other side of the partition and the heat storage tank. A baffle space is formed between the partition and the bottom side of the heat storage tank. A water collection hopper is provided in the baffle space corresponding to the position of the first heat storage section, and an ash collection hopper is provided in the baffle space corresponding to the position of the second heat storage section.

[0012] According to some embodiments of the present invention, a baffle block is connected to the bottom side of the baffle, the two sides of the baffle block are inclined from top to bottom in a direction away from each other, and a filter screen is connected to the bottom side of the baffle block, the filter screen extending downward to the position between the water collection hopper and the ash collection hopper.

[0013] According to some embodiments of the present invention, the heat storage box is further surrounded by a dispersion section located below the first heat storage section, and the heat storage body further includes a dispersion element filled in the dispersion section.

[0014] A combustion system includes a heating furnace, at least two of the above-mentioned regenerative ammonia burners, wherein the exhaust channels of the at least two regenerative ammonia burners are connected to the heating furnace, the exhaust port of one of the regenerative ammonia burners is connected to the regenerative flow channel, and the combustion-supporting port of the other regenerative ammonia burner is connected to the regenerative flow channel.

[0015] This technical solution has at least the following beneficial effects: During operation, at least two regenerative ammonia burners are connected to the heating furnace, switching between combustion and flue gas states respectively. The regenerative ammonia burner connected to the regenerative flow channel via the combustion-supporting gas interface is in combustion state, and this regenerative ammonia burner heats the interior of the heating furnace through the exhaust flow channel. The regenerative ammonia burner connected to the regenerative flow channel via the exhaust gas interface is in flue gas state, and the flue gas inside the heating furnace is output to this regenerative ammonia burner. In this way, the regenerative ammonia burner in the flue gas state collects and utilizes the waste heat of the combustion flue gas to heat the regenerative body before switching to combustion state. The combustion-supporting gas flows through the heated regenerative body, significantly reducing flue gas heat loss and improving overall thermal efficiency. At the same time, it can significantly broaden the combustible range of ammonia and reduce the difficulty of ammonia ignition. In addition, the premixed flow channel can enhance the mixing of air and fuel and prolong the residence time, while causing some ammonia to decompose at high temperature, which helps the stable ignition and combustion of ammonia. Furthermore, the integrated flue gas purification structure design reduces the escape emission of nitrogen oxides and ammonia.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly explained below. Obviously, the described drawings are only a part of the embodiments of the present invention, and not all of them. Those skilled in the art can obtain other design schemes and drawings based on these drawings without creative effort.

[0018] Figure 1 This is a perspective view of the regenerative ammonia burner of the present invention.

[0019] Figure 2 This is a side view of the regenerative ammonia burner of the present invention.

[0020] Figure 3 yes Figure 2 A schematic diagram of the cross-sectional structure at position AA.

[0021] Figure 4 yes Figure 2 A schematic diagram of the cross-sectional structure at the BB position.

[0022] In the attached diagram: 100-heat storage box, 111-first heat storage section, 112-second heat storage section, 113-denitrification section, 114-third heat storage section, 115-dispersion section, 120-partition plate, 130-water collection hopper, 140-ash collection hopper, 150-baffle block, 160-filter screen, 200-combustion shell, 210-transfer chamber, 220-air outlet channel, 230-diversion groove, 240-air inlet pipe, 250-premixing channel, 251-connecting hole, 252-narrowing section, 253-mixing section, 260-airflow channel, 270-cooling jacket, 271-cold air connection pipe, 300-ignition and denitrification integrated gun. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0025] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0026] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0027] In the description of this application, unless otherwise expressly specified and limited, the terms "set up," "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 application based on the specific circumstances.

[0028] In the description of this application, the use of terms such as "one embodiment," "some embodiments," "an example," "some instances," "some embodiments," "illustrative embodiment," "example," "specific example," and "some examples" indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0029] Reference Figures 1 to 3 According to a first aspect of the present invention, a regenerative ammonia burner includes a heat storage box 100, a combustion shell 200, and an integrated ignition and denitrification gun 300. The heat storage box 100 has a heat storage channel inside, which is filled with a heat storage medium. A three-way reversing valve is provided on the outer side of the heat storage box 100 near the heat storage channel, the three-way reversing valve having a flue gas outlet and a combustion-supporting outlet. The combustion shell 200 has a transfer chamber 210 and an outlet gas channel 220 separated from each other inside. The outlet gas channel 220 extends to one side of the combustion shell 200 in a direction away from the transfer chamber 210. A diversion groove 230 is provided at the end of the transfer chamber 210 near the outlet gas channel 220. An inlet pipe 240 passes through the end of the transfer chamber 210 away from the outlet gas channel 220. The combustion shell 200 extends to the diversion channel 230. Multiple premixed channels 250 are arranged within the combustion shell 200 between the transfer chamber 210 and the outlet channel 220. These premixed channels 250 are arranged around the diversion channel 230. A connecting hole 251 is provided between each premixed channel 250 and the side wall of the diversion channel 230. The combustion shell 200 is connected to the outside of the heat storage box 100. An airflow channel 260 is provided within the combustion shell 200 between one side of the transfer chamber 210 and the other end of the heat storage channel. An ignition-denitrification integrated gun 300 is inserted into the outlet channel 220. Naturally, the ignition-denitrification integrated gun 300 has two different functions: it can be used as an igniter in combustion mode, and it can spray ammonia gas for denitrification in exhaust mode.

[0030] As described above, the regenerative ammonia burner has two operating states: combustion and flue gas exhaust. When used in flue gas exhaust mode, the exhaust port is connected to the regenerative flow channel. At this time, the exhaust gas is connected to an external heating furnace, such as a kiln or casting furnace, through the exhaust flow channel 220. After the flue gas enters the exhaust flow channel 220, the ignition and denitrification integrated gun 300 injects ammonia gas. The ammonia flow rate is adjusted in real time according to the detected nitrogen oxide emission concentration, and the ratio of ammonia to compressed air is controlled to be below the combustible range. The injected ammonia gas undergoes selective non-catalytic reduction with the nitrogen oxides in the flue gas. When used, the gas is mixed as it flows through the premixing channel 250 to further improve the reaction efficiency. Some nitrogen oxides are reduced to nitrogen and water, which then enter the heat storage channel from the transfer chamber 210 and the airflow channel 260. After exchanging heat with the heat storage body in the heat storage channel, the gas is discharged from the exhaust port. At this time, the heat storage body effectively recovers the heat from the flue gas. When used in combustion mode, the combustion gas interface is connected to the heat storage channel, and combustion gas is supplied from the combustion gas interface. When the combustion gas flows through the heat storage body, it is heated by the heat storage body and its temperature rises. The gas flows from the airflow channel 260 to the heat storage channel. When the gas reaches the transfer chamber 210, it is a high-temperature combustion-supporting gas. The inlet pipe 240 is used to connect to an external ammonia gas source. The ammonia gas supplied from the inlet pipe 240 enters the distribution tank 230 and then enters the premixing channel 250 through the connecting hole 251. When the high-temperature combustion-supporting gas inside the transfer chamber 210 enters the outlet gas channel 220 from the premixing channel 250, it mixes rapidly and evenly with the ammonia gas. Some of the ammonia gas is decomposed into hydrogen gas at high temperature to support the combustion of ammonia gas. The mixture after entering the outlet gas channel 220 is ignited by the ignition and denitrification integrated gun 300, resulting in a violent combustion reaction. This generates a large flame and high-temperature flue gas, which supplies heat to the interior of the heating furnace. In this way, the waste heat of the combustion flue gas is collected and utilized to heat the heat storage body during the exhaust state. During the combustion state, the combustion-supporting gas flows through the heated heat storage body, which significantly reduces the heat loss of the exhaust flue gas and improves the overall thermal efficiency. At the same time, it can significantly broaden the combustible range of ammonia and reduce the difficulty of ammonia ignition. In addition, the premixed flow channel 250 can enhance the mixing of air and fuel and extend the residence time, while causing some ammonia to be decomposed at high temperature, which helps the stable ignition and combustion of ammonia.

[0031] To further improve the mixing effect of the gas mixture, in this embodiment, the premixing channel 250 extends obliquely from the transfer chamber 210 to the outlet channel 220 in a direction deviating from the axis of the outlet channel 220. The mixed gas passing through the premixing channel 250 enters the outlet channel 220 obliquely in a direction deviating from the axis of the outlet channel 220, forming a swirling flow inside the outlet channel 220, thereby improving the uniformity of the mixed gas. Furthermore, the swirling flow can prolong the residence time of the mixed gas in the outlet channel 220, thereby prolonging the combustion reaction time and helping to stabilize ammonia combustion.

[0032] To improve the effect of ammonia gas located in the diversion tank 230 entering the premixing channel 250 and mixing, in this embodiment, as follows: Figure 4As shown, the premixed flow channel 250 includes a narrowing section 252 and a mixing section 253 connected to each other. The inner diameter of the narrowing section 252 gradually decreases towards the mixing section 253. The narrowing section 252 is connected to the transfer chamber 210. The mixing section 253 is provided with a plurality of connecting holes 251 along its extension direction and is connected to the outlet flow channel 220. Because the inner diameter of the narrowing section 252 gradually decreases towards the mixing section 253, the flow velocity of the combustion-supporting gas increases when it passes through the narrowing section 252. Thus, a large negative pressure suction can be formed in the mixing section 253. Ammonia gas located in the diversion channel 230 enters the mixing section 253 through the plurality of connecting holes 251 connected to the mixing section 253 for mixing. At this time, the ammonia gas is violently mixed with the high-temperature combustion-supporting gas, and some of the ammonia gas is decomposed into hydrogen and nitrogen gas at high temperature. This negative pressure also avoids the risk of explosion caused by high-temperature air entering the ammonia gas pipeline.

[0033] Unconstrained swirling flow can cause the airflow to expand outwards, resulting in incomplete combustion of the outer layer of ammonia and air. Therefore, in this embodiment, the outlet airflow duct 220 is provided with a contraction section, the inner diameter of which gradually decreases in the direction away from the heat storage tank 100. When the ammonia and combustion-supporting gas entering the outlet airflow duct 220 pass through the contraction section with its gradually decreasing inner diameter, the airflow can be further constrained, allowing the outer layer of airflow to return to the high-temperature center for combustion again, thereby improving the combustion rate.

[0034] The intake pipe 240 operates at a high temperature. To ensure its service life, in this embodiment, a cooling sleeve 270 is fitted around the outer side of the intake pipe 240. An airflow gap is formed between the inner wall of the cooling sleeve 270 and the outer wall of the intake pipe 240. The airflow gap is connected to the diversion groove 230. One end of the cooling sleeve 270 extends out of the heat storage box 100 and is connected to a cold air pipe 271. Naturally, a sealing structure such as a sealing ring is provided between the end of the cooling sleeve 270 extending out of the heat storage box 100 and the intake pipe 240 to prevent airflow from escaping outward from this position. In combustion or exhaust mode, the cold air pipe 271 can be connected to an external cold air source. The cold air source supplies cold air into the airflow gap through the cold air pipe 271, which promptly removes the heat from the intake pipe 240 and extends the service life of the intake pipe 240. The cold air after passing through the intake pipe 240 is heated and finally flows into the distribution channel 230, where it enters the premixed flow channel 250 as combustion aid.

[0035] In addition to recovering heat from flue gas, the heat storage channel can also denitrate the flue gas. Specifically, the heat storage channel includes a first heat storage section 111, a second heat storage section 112, a denitrification section 113, and a third heat storage section 114 connected in sequence. The heat storage body includes a phase change heat storage element filled in the first heat storage section 111, a denitrification catalyst filled in the denitrification section 113, a first ceramic heat storage element filled in the second heat storage section 112, and a second ceramic heat storage element filled in the third heat storage section 114. In practical applications, the phase change heat storage element can be an inorganic hydrated salt or paraffin hydrocarbon, etc., with a melting point of 40~50℃, which can undergo solid-liquid phase change or solid-solid phase change when the temperature changes, realizing the rapid absorption or release of a large amount of heat. The first ceramic heat storage element can be a low-temperature ceramic heat storage ball; the denitrification catalyst can be an SCR catalyst ball layer; and the second ceramic heat storage element can be a high-temperature ceramic heat storage ball. In the exhaust state, the high-temperature flue gas first passes through the third heat storage section 114, where the high-temperature ceramic heat storage balls absorb and store the heat of the high-temperature flue gas. After passing through the third heat storage section 114, the flue gas enters the denitrification section 113. Under the catalytic action of the SCR catalytic balls, the nitrogen oxides in the flue gas are reduced to N2 and H2O by the residual ammonia in the flue gas. At the same time, the SCR catalytic balls are also heat-exchanged by the high-temperature flue gas and store some heat. Then the flue gas enters the second heat storage section 112, where the low-temperature ceramic heat storage balls absorb the heat of the flue gas again. Finally, it passes through the phase change heat storage material, where the phase change heat storage material melts and absorbs a large amount of heat from the flue gas, causing the flue gas temperature to drop to 60~70℃ and producing a large amount of condensate. In the combustion state, the combustion-supporting gas first passes through the first heat storage section 111, where it is preheated by the phase change heat storage element. Then it is gradually heated through the second heat storage section 112, the denitrification section 113, and the third heat storage section 114 before finally entering the combustion shell 200.

[0036] As a specific embodiment of forming a first heat storage section 111, a second heat storage section 112, a denitrification section 113, and a third heat storage section 114 within the heat storage tank 100, a downwardly extending partition 120 is provided on the top side of the heat storage tank 100. The first heat storage section 111 is formed between one side of the partition 120 and the heat storage tank 100, and the second heat storage section 112, the denitrification section 113, and the third heat storage section 114 are formed between the other side of the partition 120 and the heat storage tank 100. A baffle space is formed between the partition 120 and the bottom side of the heat storage tank 100. A water collection hopper 130 is provided in the baffle space corresponding to the position of the first heat storage section 111, and an ash collection hopper 140 is provided in the baffle space corresponding to the position of the second heat storage section 112. The flue gas contains dust. After passing through the third heat storage section 114, the denitrification section 113 and the second heat storage section 112, it bypasses the partition 120. At this time, the dust will be thrown into the ash collection hopper 140 below for collection. When passing through the first heat storage section 111, the flue gas temperature drops below the dew point, and the moisture in the flue gas begins to condense and drip into the water collection hopper 130 below for collection.

[0037] To extend the flow path of flue gas around baffle 120, in this embodiment, a baffle block 150 is connected to the bottom side of baffle 120. The two sides of the baffle block 150 are inclined from top to bottom in directions away from each other. A filter screen 160 is connected to the bottom side of the baffle block 150, and the filter screen 160 extends downward to the position between the water collection hopper 130 and the ash collection hopper 140. After passing through the first heat storage section 111, the flue gas is inclined and guided by the top side of the baffle block 150 to form a larger flow around it in the deflection space, thereby increasing the space through which the airflow passes in the deflection space.

[0038] According to some embodiments of the present invention, the heat storage box 100 is further surrounded by a dispersion section 115 located below the first heat storage section 111. The heat storage body also includes a dispersion element filled in the dispersion section 115. The dispersion element can be a metal ball, a porous metal layer, etc., mainly used to increase the spreading area of ​​water droplets falling on the dispersion element, so that the water droplets have more sufficient contact with the flue gas. In the flue gas exhaust state, after the flue gas enters the packing layer, it exchanges heat with the metal packing and the liquid droplets wetted on the surface of the packing. The flue gas temperature drops below the dew point, and the moisture in the flue gas begins to condense. The condensate wets the surface of the dispersion element, increasing the gas-liquid contact area to continue dissolving residual ammonia, NO2, SO2, and SO3 in the flue gas. Finally, it flows to the water hopper under the action of gravity. In the combustion state, the combustion-supporting gas blows the liquid droplets wetted on the surface of the dispersion element down and blows off some of the dissolved ammonia for secondary combustion.

[0039] In summary, the regenerative burner operates under combustion conditions, including the following steps:

[0040] S1. In the regenerative burner in combustion state, the combustion gas enters the regenerator chamber through a three-way valve. It first passes through the first regenerator section 111 and the dispersion section 115 for preliminary preheating. The liquid droplets wetting the surface of the dispersion are blown off, and some of the dissolved ammonia is blown off for secondary combustion and utilization.

[0041] S2. After passing through the dispersion section 115, the combustion-supporting gas enters the baffle space. Under the action of gravity and centrifugal force, it falls and throws the droplets to the water bucket at the bottom of the first heat storage section 111. At the same time, some of the ammonia dissolved in the water bucket is blown off for secondary combustion. When the combustion-supporting gas passes through the filter screen 160, it blows the dust that was periodically filtered by the filter screen in the previous flue gas state in the opposite direction. The blown-off dust falls into the ash hopper under the action of gravity and centrifugal force.

[0042] S3. The combustion gas through the baffle space flows sequentially through the second heat storage section 112, the denitrification section 113 and the third heat storage section 114. After being heated to a temperature 50°C~100°C lower than the kiln exhaust temperature by exchanging heat with each section, it enters the combustion shell 200.

[0043] S4. Ammonia enters the diversion tank 230 through the inlet pipe 240 and mixes rapidly and evenly with the high-temperature combustion-supporting gas in the swirl premixing section. Some of the ammonia is decomposed into H2 and N2 combustion-supporting gas at high temperature.

[0044] S5. The mixed gas exiting the swirl premixing section rotates into the contraction section. The contraction section constrains the swirl to prevent it from expanding outwards and lengthens the residence time of the mixed gas to ensure that ammonia and air are fully mixed and undergo combustion. At this time, the ratio of ammonia to compressed air in the ignition and denitrification integrated gun 300 is within the flammable range. It is ignited by the electric arc spark generated by the igniter to form a small flame. Meanwhile, the mixed gas at the outlet of the gas outlet channel 220 is ignited by the small flame of the ignition and denitrification integrated gun 300, resulting in a violent combustion reaction, producing a large flame and high-temperature flue gas.

[0045] When a regenerative burner operates in flue gas exhaust mode, the following steps are included:

[0046] S1. After the high-temperature flue gas heats the product in the kiln, it enters the outlet flow channel 220 of the regenerative burner in the flue gas exhaust state. The ignition and denitrification integrated gun 300 of the regenerative burner in the flue gas exhaust state adjusts the ammonia flow rate in real time according to the NOx emission concentration detected at the end, and controls the ratio of ammonia and compressed air to be far below the combustible range. The injected ammonia reacts with the nitrogen oxides in the flue gas in the SNCR reaction, and some nitrogen oxides are reduced to N2 and H2O.

[0047] S2. After SNCR denitrification, the flue gas passes through the third heat storage section 114. The high-temperature ceramic heat storage ball absorbs and stores the heat of the high-temperature flue gas. The height of the third heat storage section 114 is designed to control the flue gas temperature at the outlet of the third heat storage section 114 to be about 400℃.

[0048] S3. After passing through the third heat storage section 114, the flue gas enters the denitrification section 113. Under the catalytic action of the SCR catalytic ball, the nitrogen oxides in the flue gas are reduced to N2 and H2O by the residual ammonia in the flue gas. At the same time, the denitrification section 113 is also heat-exchanged by the high-temperature flue gas and stores some heat. The outlet flue gas temperature of the denitrification section 113 is about 180℃.

[0049] S4. After passing through the denitrification section 113, the flue gas enters the low-temperature ceramic regenerator section. After heating the ceramic regenerator, the outlet flue gas temperature drops to about 130°C.

[0050] S5. After passing through the low-temperature ceramic heat storage ball section, the flue gas enters the baffle space. Some of the dust is thrown into the ash hopper under the action of gravity and centrifugal force, while most of the remaining dust is blocked by the filter screen.

[0051] S6. The flue gas after passing through the filter screen 160 flows in the opposite direction to the condensate falling from the upper dispersion section 115. Some of the condensate vaporizes and absorbs heat, causing the flue gas temperature to drop to near the flue gas dew point. At the same time, the remaining condensate dissolves residual ammonia, NO2, SO2, and SO3 in the flue gas, captures trace amounts of dust, and falls into the water hopper. After entering the dispersion section 115, the flue gas exchanges heat with the liquid droplets wetting the surface of the dispersion body. The flue gas temperature drops below the dew point, and the moisture in the flue gas begins to condense. The condensate wets the surface of the packing material, increases the gas-liquid contact area, and continues to dissolve residual ammonia, NO2, SO2, and SO3 in the flue gas. Finally, it flows into the water hopper under the action of gravity.

[0052] S7. The flue gas passing through the dispersion section 115 enters the first heat storage section 111. The phase change heat storage material is an inorganic hydrated salt or paraffin hydrocarbon with a melting point of 40~50℃. The phase change heat storage material melts and absorbs a large amount of heat from the flue gas, causing the flue gas temperature to drop to 60~70℃ and generating a large amount of condensate. The condensate flows into the dispersion section 115 under the action of gravity.

[0053] A combustion system includes a heating furnace, at least two of the above-mentioned regenerative ammonia burners, with the exhaust ducts 220 of the at least two regenerative ammonia burners connected to the heating furnace, the flue gas outlet of one of the regenerative ammonia burners connected to the regenerative flow channel, and the combustion-supporting port of the other regenerative ammonia burner connected to the regenerative flow channel.

[0054] In this combustion system, at least two regenerative ammonia burners are connected to the heating furnace during operation. The combustion and exhaust states are switched by a three-way reversing valve. The regenerative ammonia burner connected to the regenerative flow channel via the combustion gas interface is in combustion mode, and this regenerative ammonia burner heats the interior of the heating furnace through the exhaust flow channel 220. The regenerative ammonia burner connected to the regenerative flow channel via the exhaust flow channel is in exhaust mode, and the flue gas inside the heating furnace is output to this regenerative ammonia burner. In this way, the regenerative ammonia burner in exhaust mode collects and utilizes the waste heat of the combustion flue gas to heat the regenerative body before switching to combustion mode. The combustion gas flows through the heated regenerative body, which significantly reduces the heat loss of the exhaust gas and improves the overall thermal efficiency. At the same time, it can significantly broaden the combustible range of ammonia and reduce the difficulty of ammonia ignition. In addition, the premixing flow channel 250 can enhance the mixing of air and fuel and prolong the residence time, while causing some ammonia to be decomposed at high temperature, which helps the stable ignition and combustion of ammonia.

[0055] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A regenerative ammonia burner, characterized in that: include: A heat storage box (100) has a heat storage channel inside, which is filled with a heat storage body. A three-way reversing valve is provided on the outside of the heat storage box (100) near the heat storage channel. The three-way reversing valve has a smoke exhaust port and a combustion-supporting port. The heat storage channel includes a first heat storage section (111), a second heat storage section (112), a denitrification section (113), and a third heat storage section (114) connected in sequence. The heat storage body includes a phase change heat storage element filled in the first heat storage section (111), a denitrification catalyst filled in the denitrification section (113), a first ceramic heat storage element filled in the second heat storage section (112), and a second ceramic heat storage element filled in the third heat storage section (114). The heat storage box (100) has a downwardly extending partition (120) on its top side. The partition (120) and the heat storage box (100) together form a first heat storage section (111). The partition (120) and the heat storage box (100) together form a second heat storage section (112), a denitrification section (113), and a third heat storage section (114). A baffle space is formed between the partition (120) and the bottom side of the heat storage box (100). A water collection hopper (130) is provided in the baffle space corresponding to the position of the first heat storage section (111). A dust collection hopper (140) is provided in the baffle space corresponding to the position of the second heat storage section (112). The combustion shell (200) has a transfer chamber (210) and an outlet air passage (220) that are separated from each other. The outlet air passage (220) extends to the side of the combustion shell (200) away from the transfer chamber (210). A diversion groove (230) is provided at the end of the transfer chamber (210) near the outlet air passage (220). An intake pipe (240) passes through the end of the transfer chamber (210) away from the outlet air passage (220). The intake pipe (240) extends to the diversion groove (230). Multiple premixed channels (250) are provided between the transfer chamber (210) and the outlet air passage (220). The multiple premixed channels (250) are arranged around the diversion groove (230). A connecting hole (251) is provided between the multiple premixed channels (250) and the side wall of the diversion groove (230). The combustion shell (200) is connected to the outside of the heat storage box (100). An airflow channel (260) is provided inside the combustion shell (200) between one side of the transfer chamber (210) and the other end of the heat storage channel. The ignition and denitrification integrated gun (300) is inserted into the airflow channel (220).

2. A regenerative ammonia burner according to claim 1, characterized in that: The premixed flow channel (250) extends obliquely from the transfer chamber (210) to the outlet flow channel (220) in a direction offset from the axis of the outlet flow channel (220).

3. A regenerative ammonia burner according to claim 1, characterized in that: The premixed flow channel (250) includes a narrowing section (252) and a mixing section (253) connected to each other. The inner diameter of the narrowing section (252) gradually decreases in the direction close to the mixing section (253). The narrowing section (252) is connected to the transfer chamber (210). The mixing section (253) is provided with a plurality of the connecting holes (251) along its extension direction. The mixing section (253) is connected to the outlet flow channel (220).

4. A regenerative ammonia burner according to claim 1, characterized in that: The air outlet duct (220) is provided with a contraction section, the inner diameter of which gradually decreases in the direction away from the heat storage box (100).

5. A regenerative ammonia burner according to claim 1, characterized in that: A cooling sleeve (270) is fitted on the outer side of the air intake pipe (240). An airflow gap is formed between the inner wall of the cooling sleeve (270) and the outer wall of the air intake pipe (240). The airflow gap is connected to the diversion groove (230). One end of the cooling sleeve (270) extends out of the heat storage box (100) and is connected to a cold air pipe (271).

6. A regenerative ammonia burner according to claim 1, characterized in that: The bottom side of the partition (120) is connected to a baffle block (150). The two sides of the baffle block (150) are inclined from top to bottom in a direction away from each other. The bottom side of the baffle block (150) is connected to a filter screen (160). The filter screen (160) extends downward to the position between the water collection hopper (130) and the ash collection hopper (140).

7. A regenerative ammonia burner according to claim 1, characterized in that: The heat storage box (100) is located below the first heat storage section (111) and a dispersion section (115) is also formed therein. The heat storage body also includes a dispersion element filled in the dispersion section (115).

8. A combustion system, characterized in that: It includes a heating furnace, at least two regenerative ammonia burners as described in any one of claims 1 to 7, the outlet air passages (220) of at least two of the regenerative ammonia burners being connected to the heating furnace, the exhaust port of one of the regenerative ammonia burners being connected to the regenerative flow passage, and the combustion-supporting port of the other regenerative ammonia burner being connected to the regenerative flow passage.

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