Ammonia combustion system and control method

Abstract

The application discloses an ammonia combustion system and a control method. The ammonia combustion system comprises a furnace, an ammonia gas preparation device, a burner, a denitration device, a temperature detection device and a control device. The ammonia gas preparation device is used for preparing ammonia-containing gas. The burner is arranged in the furnace and used for spraying the ammonia-containing gas into the furnace. The spraying position of the burner is adjustable. The denitration device is arranged in the furnace and used for spraying ammonia-containing solution. The spraying position of the denitration device is adjustable. The temperature detection device is used for obtaining temperature distribution information along a first direction in the furnace. The control device is connected with the temperature detection device, the burner and the denitration device respectively. The control device is used for controlling the spraying position of the burner to spray the ammonia-containing gas into a first target area in a preset nitrogen inhibition temperature interval in the furnace according to the temperature distribution information, and controlling the spraying position of the denitration device to spray the ammonia-containing solution into a second target area in a preset denitration temperature interval in the furnace.

Description

Technical Field

[0001] This application relates to the field of ammonia combustion in power plants, specifically to an ammonia combustion system and control method. Background Technology

[0002] The power industry is actively exploring the application of ammonia as a zero-carbon fuel. However, due to the dynamic temperature range of the ammonia combustion furnace, the combustion state of ammonia is complex and variable, and the interaction mechanism between ammonia, oxygen, and generated nitrogen oxides in the furnace is complex, making it difficult to control nitrogen oxide emissions. Summary of the Invention

[0003] This application provides an ammonia combustion system and control method. By real-time monitoring of the temperature distribution information of the furnace through a temperature detection device, the control device determines the first target area of ​​the preset nitrogen suppression temperature range and the second target area of ​​the preset denitrification temperature range in real time, and adjusts the injection position of the burner and the injection position of the denitrification device in real time to achieve control of the nitrogen oxide concentration in the ammonia combustion system.

[0004] In a first aspect, embodiments of this application provide an ammonia combustion system, comprising: a furnace; an ammonia preparation device for preparing ammonia-containing gas; a burner disposed in the furnace, the burner being used to inject the ammonia-containing gas into the furnace, and the injection position of the burner being adjustable; a denitrification device disposed in the furnace, the denitrification device being used to inject an ammonia-containing solution, and the injection position of the denitrification device being adjustable; a temperature detection device for acquiring temperature distribution information along a first direction within the furnace; and a control device connected to the temperature detection device, the burner, and the denitrification device, the control device being used to control the injection position of the burner according to the temperature distribution information to inject the ammonia-containing gas into a first target area within a preset nitrogen suppression temperature range in the furnace, and to control the injection position of the denitrification device to inject the ammonia-containing solution into a second target area within a preset denitrification temperature range in the furnace.

[0005] In one possible implementation, the ammonia combustion system further includes: a nitrogen oxide concentration monitoring device for acquiring nitrogen oxide concentration data in the furnace; the nitrogen oxide concentration monitoring device is connected to the control device, and the control device compares the nitrogen oxide concentration data with a preset nitrogen oxide concentration threshold to control the start and stop of the denitrification device.

[0006] In one possible implementation, the control device pre-stores a flame center temperature estimation model, and the control device identifies the first target area and the second target area based on the temperature distribution information and the flame center temperature estimation model.

[0007] In one possible implementation, the preset nitrogen suppression temperature range is 900℃-1200℃; and / or the preset denitrification temperature range is 900℃-1100℃.

[0008] In one possible implementation, the ammonia preparation apparatus includes: an ammonia preparation unit for preparing ammonia from ammonia water and outputting a first ammonia stream and a second ammonia stream; an ammonia cracking unit for catalytically cracking the first ammonia stream to generate a first mixed gas, the first mixed gas containing hydrogen; and a mixing unit for mixing the first mixed gas with the second ammonia stream to form the ammonia-containing gas.

[0009] In one possible implementation, the ammonia preparation unit includes: an ammonia water supplier for storing an ammonia-containing solution and outputting a first ammonia-containing solution and a second ammonia-containing solution, the second ammonia-containing solution being input into the denitrification device; an ammonia water vaporizer connected to the ammonia water vaporizer for vaporizing the first ammonia-containing solution to generate a second mixed gas, the second mixed gas containing ammonia and first water vapor; a mixed gas separator connected to the ammonia water vaporizer for separating the ammonia from the second mixed gas; and an ammonia storage unit connected to the mixed gas separator for storing the ammonia and dividing the ammonia into the first ammonia and the second ammonia for output.

[0010] In one possible implementation, the output end of the ammonia storage device is provided with a flow regulating valve, which is used to regulate the flow rates of the first ammonia stream and the second ammonia stream.

[0011] In one possible implementation, the ammonia cracking unit includes: an ammonia heater connected to the ammonia storage tank, the ammonia heater being used to heat the first stream of ammonia at a preset catalytic temperature; and an ammonia fixed-bed reactor connected to the ammonia heater, the ammonia fixed-bed reactor being used to catalytically crack the heated first stream of ammonia through a catalyst to generate a first mixed gas.

[0012] In one possible implementation, the gas separator includes: a first gas separator connected to the ammonia vaporizer, the first gas separator being used to separate a third gas mixture from the second gas mixture, the third gas mixture containing the ammonia and second water vapor; and a second gas separator connected to the first gas separator, the second gas separator being used to separate the ammonia from the third gas mixture.

[0013] Secondly, embodiments of this application provide a method for controlling ammonia combustion, which is applied to the ammonia combustion system provided in the first aspect of this application. The method includes: acquiring temperature distribution information along a first direction within the ammonia combustion region; determining a first target region where the ammonia combustion region is within a preset nitrogen suppression temperature range and a second target region where the ammonia combustion region is within a preset denitrification temperature range; controlling a first injector to inject ammonia-containing gas into the first target region; and controlling a second injector to inject ammonia-containing solution into the second target region.

[0014] The ammonia combustion system and control method provided in this application embodiment, based on the temperature distribution information in the furnace detected by the temperature detection device, are equipped with an adjustable burner injection mechanism and an adjustable denitrification device injection mechanism to achieve independent operation of combustion nitrogen suppression and denitrification, thereby reducing the concentration of nitrogen oxides. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the ammonia combustion system provided in the embodiments of this application; Figure 2 This is a schematic flowchart of the ammonia combustion control method provided in the embodiments of this application.

[0017] Explanation of reference numerals in the attached figures: 1-Ammonia combustion system; 10-Burner; 20-Denitrification device; 30-Ammonia water supplier; 40-Ammonia water vaporizer; 50-First mixed gas separator; 60-Second mixed gas separator; 70-Ammonia storage tank; 80-Ammonia heater; 90-Ammonia fixed bed reactor; 100-Mixing unit; 110-Nitrogen oxide concentration monitoring device; 120-Condenser. Detailed Implementation

[0018] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] The terms "setup" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0020] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different locations and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0021] The power industry is actively exploring applications of ammonia as a zero-carbon fuel, and ammonia water storage exhibits significant comprehensive advantages compared to pure ammonia. Firstly, the atmospheric pressure storage characteristic of ammonia water avoids the high-pressure or low-temperature storage conditions required for liquid ammonia, reducing the risk of explosions and poisoning from leaks, which is crucial for the densely populated power plant environment. Secondly, ammonia water storage does not require expensive high-pressure containers and insulation systems; ordinary stainless steel or PE storage tanks suffice. Furthermore, ammonia water can be decomposed on demand using low-grade waste heat from power plants, improving energy efficiency and allowing for flexible adjustment of the co-firing ratio. The residual water after decomposition can be directly reused in the desulfurization system, forming a closed-loop resource system. However, ammonia combustion inevitably leads to increased nitrogen oxide emissions in the furnace. Moreover, the temperature range of the ammonia combustion furnace is dynamic, and the combustion state is complex and variable. The interaction mechanisms between ammonia, oxygen, and generated nitrogen oxides within the furnace are complex, making it difficult to control nitrogen oxide emissions.

[0022] Firstly, such as Figure 1 As shown in the figure, this application provides an ammonia combustion system 1, including a furnace, an ammonia preparation device, a burner 10, a denitrification device 20, a temperature detection device, and a control device.

[0023] The furnace is the main space for ammonia combustion. Based on the state of ammonia combustion, the furnace can be divided into the main combustion zone and the furnace outlet burnout zone.

[0024] The ammonia preparation unit can produce ammonia-containing gas. This ammonia-containing gas is the main fuel in the furnace. The ammonia-containing gas can be a mixture of ammonia and hydrogen.

[0025] The burner 10 is installed in the main combustion zone of the furnace. The burner 10 injects ammonia-containing gas into the furnace. The injection position of the burner 10 is adjustable. By adjusting the injection position of the burner 10, efficient combustion can be achieved in the furnace under all operating conditions.

[0026] The denitrification device 20 is installed in the combustion zone at the furnace outlet. The denitrification device 20 can spray ammonia-containing solution into the furnace. The denitrification device 20 can be a retractable flute-shaped tube or a nozzle spray gun. The spray position of the denitrification device 20 is adjustable. By adjusting the spray position of the denitrification device 20, efficient denitrification of the furnace can be achieved under all operating conditions.

[0027] Temperature detection devices are installed in the furnace. These devices can collect temperature distribution information along directions of significant temperature variation within the furnace. Alternatively, they can be deployed along the entire longitudinal direction of the furnace to collect temperature distribution information at different heights. The arrangement of the temperature detection devices covers both the main combustion zone and the burnout zone at the furnace outlet. The temperature detection devices can be distributed optical fibers, spaced 3-4 meters apart on the fins of the four water-cooled walls of the furnace. This allows for real-time tracking of temperature shifts caused by load fluctuations and combustion fluctuations.

[0028] The control device is connected to the temperature detection device, burner 10, and denitrification device 20 to receive temperature distribution information, process data, and issue control commands. The injection positions of burner 10 and denitrification device 20 can be independently adjusted by the control device, simultaneously achieving ammonia combustion for nitrogen suppression and denitrification.

[0029] The control device can control the injection position of the burner 10 based on temperature distribution information to inject ammonia-containing gas into the first target area within the preset nitrogen suppression temperature range of the furnace. When the ammonia-containing gas is injected into the furnace within the preset nitrogen suppression temperature range, the hydrogen in the ammonia-containing gas consumes the oxygen in the furnace, reducing the oxygen ion concentration in the combustion zone and thus inhibiting the reaction of ammonia with oxygen to form nitrogen oxides. Within the preset nitrogen suppression temperature range, the ammonia reacts with the nitrogen oxides in the combustion zone, converting them into nitrogen, thereby reducing the concentration of nitrogen oxides in the combustion zone.

[0030] The control device can control the injection position of the denitrification device 20 based on temperature distribution information, so as to inject the ammonia-containing solution into the second target area within the preset denitrification temperature range of the furnace. Under the injection of the denitrification device, the ammonia-containing solution forms tiny droplets. The high-temperature environment within the preset denitrification temperature range causes the ammonia-containing solution to decompose, generating ammonia gas and water vapor. The ammonia gas undergoes a non-selective catalytic reduction reaction with nitrogen oxides in the combustion zone at the furnace outlet, converting the nitrogen oxides into ammonia gas, thereby reducing the concentration of nitrogen oxides in the combustion zone at the furnace outlet and ensuring that the nitrogen oxide concentration in the ammonia combustion system 1 meets the standard. Water vapor does not affect the non-selective catalytic reduction reaction, nor does it cause problems such as furnace corrosion.

[0031] Thus, by installing a temperature detection device inside the furnace to monitor the temperature distribution, and based on the temperature analysis, a first target area within a preset nitrogen suppression temperature range and a second target area within a preset denitrification temperature range are determined. This allows for the control of the injection positions of the burner 10 and the denitrification device, injecting ammonia-containing gas and ammonia-containing solution into the first and second target areas, respectively. Within the preset nitrogen suppression temperature range, the generation of nitrogen oxides is reduced, thereby lowering the initial concentration of nitrogen oxides in the combustion zone at the furnace outlet. Then, within the preset denitrification temperature range, the generated nitrogen oxides are removed, further reducing the nitrogen oxide concentration within the furnace, thus achieving control of the nitrogen oxide concentration in the ammonia combustion system 1.

[0032] In some embodiments, the ammonia combustion system 1 further includes a nitrogen oxide concentration monitoring device 110. The nitrogen oxide concentration monitoring device 110 can continuously collect nitrogen oxide concentration data in the furnace in real time. The nitrogen oxide concentration monitoring device 110 can be installed in the combustion zone at the furnace outlet to collect nitrogen oxide concentration data in the flue gas at the furnace outlet.

[0033] The nitrogen oxide concentration monitoring device 110 is connected to the control device. The control device can receive nitrogen oxide concentration data collected by the nitrogen oxide concentration monitoring device 110. The control device has a preset nitrogen oxide concentration threshold. When the collected nitrogen oxide concentration data is not lower than the preset nitrogen oxide concentration threshold, the control device issues a command to control the denitrification device 20 to inject ammonia-containing solution into the furnace to reduce the nitrogen oxide concentration at the furnace outlet. When the collected nitrogen oxide concentration data is lower than the preset nitrogen oxide concentration threshold, the control device controls the denitrification device 20 to stop injecting ammonia-containing solution into the furnace.

[0034] Thus, by setting up a nitrogen oxide concentration monitoring device 110, the denitrification unit 20 can spray ammonia-containing solution on demand, eliminating the need for continuous spraying, reducing ammonia escape from the solution, lowering ammonia consumption, and reducing the operating cost of the ammonia combustion system 1. Simultaneously, by controlling the spraying of the denitrification unit using real-time nitrogen oxide concentration data collected by the monitoring device 110, the problem of excessive nitrogen oxide concentration generated by ammonia combustion can be solved, ensuring that the nitrogen oxide concentration in the furnace meets the standards.

[0035] In some embodiments, the denitrification device 20 is a retractable flute-shaped tube. When the collected nitrogen oxide concentration data is not lower than a preset nitrogen oxide concentration threshold, the control device issues a command to control the retractable flute-shaped tube to extend into the furnace and spray an ammonia-containing solution into the furnace to reduce the nitrogen oxide concentration at the furnace outlet. When the collected nitrogen oxide concentration data is lower than the preset nitrogen oxide concentration threshold, the control device controls the retractable flute-shaped tube to retract from the furnace, stopping the spraying of the ammonia-containing solution into the furnace.

[0036] Thus, by controlling the extension and retraction of the retractable flute based on the collected nitrogen oxide concentration data, the working time of the retractable flute can be reduced, wear, scaling and corrosion of the retractable flute can be slowed down, and the service life of the retractable flute can be extended.

[0037] In some embodiments, the control device is linked with the nitrogen oxide concentration monitoring device 110 and the temperature detection device. When the nitrogen oxide concentration data received by the control device is not lower than a preset nitrogen oxide concentration threshold, the control device confirms that the combustion zone at the furnace outlet is in a second target region within a preset denitrification temperature range based on the temperature distribution information detected by the temperature detection device. The control device then controls the denitrification device 20 to inject an ammonia-containing solution into the furnace according to the second target region, thereby reducing the nitrogen oxide concentration at the furnace outlet. If the second target region within the preset denitrification temperature range changes, the control device can adjust the injection position of the denitrification device 20 until the nitrogen oxide concentration data in the furnace is lower than the preset nitrogen oxide concentration threshold.

[0038] Thus, based on the temperature detection device, the control device controls the start and stop of the denitrification device 20, which can match the denitrification treatment to the preset denitrification temperature range and improve the effect of reducing nitrogen oxide concentration.

[0039] In some embodiments, the control device pre-stores a flame center temperature estimation model trained on big data. The flame center temperature estimation model uses furnace temperature distribution information as input variables.

[0040] The control device receives temperature distribution information along the first direction within the furnace collected by the temperature detection device and imports this information into the flame center temperature calculation model. Based on the temperature distribution information and the position of the temperature detection device, the flame center temperature calculation model calculates a first target region within a preset nitrogen suppression temperature range and a second target region within a preset denitrification temperature range. The control device then calculates the injection position of the burner 10 based on the first target region and the injection position of the denitrification device 20 based on the second target region.

[0041] Thus, by using a flame center temperature estimation model to calculate the flame center region, the problem of inaccurate judgment of the preset nitrogen suppression temperature range and preset denitrification temperature range under large load fluctuations in the furnace is solved. This adapts to complex operating conditions where flame center shifts due to furnace load fluctuations, fuel changes, and air distribution adjustments, thus broadening the applicability of the ammonia combustion system 1. Furthermore, setting the first and second target regions at the flame center of the preset nitrogen suppression temperature range and preset denitrification temperature range respectively can improve nitrogen suppression and denitrification effects and reduce the concentration of nitrogen oxides in the furnace.

[0042] In some embodiments, the preset nitrogen suppression temperature range is 900℃-1200℃. The control device controls the burner 10 to inject ammonia-containing gas within this temperature range, so that the ammonia-containing gas can be fully combusted. Combustion of ammonia-containing gas within the range of 900℃-1200℃ can suppress the formation of nitrogen oxides, while the combustion of ammonia-containing gas is stable.

[0043] The preset denitrification temperature range is 900℃-1100℃. The control device controls the denitrification unit 20 to inject ammonia-containing solution within this temperature range, where the ammonia solution vaporizes to generate ammonia gas. The ammonia gas undergoes a non-selective catalytic reduction reaction, acting as a reducing agent to consume nitrogen oxides in the furnace, thus achieving denitrification. If the preset denitrification temperature range is below 900℃, the reaction rate of the non-selective catalytic reduction reaction is low, the denitrification efficiency is low, and unreacted ammonia gas will escape. If the preset denitrification temperature range is above 1100℃, the ammonia gas will be oxidized by oxygen in the furnace, generating new nitrogen oxides.

[0044] Thus, by clearly defining the preset nitrogen suppression temperature range and the preset denitrification temperature range, the stability of nitrogen oxide concentration control in the ammonia combustion system 1 can be improved.

[0045] In some embodiments, the ammonia preparation apparatus includes an ammonia preparation unit, an ammonia cracking unit, and a mixing unit 100.

[0046] The ammonia production unit can produce ammonia from ammonia water, and then divide it into a first ammonia stream and a second ammonia stream. The first ammonia stream is used to produce hydrogen, and the second ammonia stream is used as fuel.

[0047] The volume of the first ammonia stream can account for 15%-20% of the total ammonia-containing gas entering burner 10. The volume of the second ammonia stream can account for 80%-85% of the total ammonia-containing gas entering burner 10.

[0048] The first stream of ammonia gas is fed into the ammonia cracking unit. The ammonia cracking unit is filled with a catalyst. The catalyst catalytically cracks the first stream of ammonia gas to produce a first mixed gas. The first mixed gas contains hydrogen gas.

[0049] Thus, producing hydrogen through ammonia cracking can save on hydrogen storage and transportation equipment, and improve the integration and on-site safety of the ammonia combustion system 1. Furthermore, partial ammonia cracking for hydrogen production, compared to full ammonia cracking, can reduce the cracking energy consumption and catalyst loss of the ammonia combustion system 1, thereby controlling its operating costs.

[0050] The mixing unit 100 uniformly mixes the first mixed gas with the second ammonia gas to form an ammonia-containing gas, which is then delivered to the burner 10. The ammonia in the ammonia-containing gas serves as fuel for the burner 10.

[0051] Thus, hydrogen in the ammonia-containing gas acts as a combustion aid for ammonia, solving the problems of difficult ignition and unstable combustion of pure ammonia, and increasing the combustion speed of ammonia. At the same time, hydrogen combustion consumes oxygen in the furnace, creating a weakly reducing atmosphere in the combustion zone. This reduces the direct oxidation of ammonia to nitrogen oxides and reduces the nitrogen oxides already generated in the furnace back to nitrogen, thereby lowering the concentration of nitrogen oxides in ammonia combustion system 1.

[0052] In some embodiments, the ammonia preparation unit includes an ammonia water supplier 30, an ammonia water vaporizer 40, a mixed gas separator, and an ammonia storage tank 70.

[0053] Ammonia water supplier 30 stores ammonia-containing solution. Ammonia water supplier 30 distributes two streams of ammonia-containing solution: a first stream and a second stream. The first stream of ammonia-containing solution is used to prepare ammonia-containing gas. The first stream of ammonia-containing solution is then fed into the denitrification unit 20 as a denitrification feedstock.

[0054] In this way, by supplying ammonia water to the burner 10 and the denitrification device 20 through the ammonia water supplier 30, a unified raw material storage for the ammonia combustion system 1 can be achieved, reducing the duplication of construction of storage tanks and pipelines.

[0055] The ammonia vaporizer 40 is connected to the ammonia supply unit 30. The ammonia vaporizer 40 receives a first ammonia-containing solution. The ammonia vaporizer 40 vaporizes the first ammonia-containing solution to generate a second mixed gas. The second mixed gas contains ammonia gas and first water vapor. The heating medium for the ammonia vaporizer 40 can be high-temperature air drawn from the secondary air box, with a temperature of 300℃-320℃.

[0056] In this way, the energy consumption of the ammonia combustion system 1 can be reduced by using the waste heat of the electric field to vaporize the ammonia water.

[0057] The gas separator is connected to the ammonia vaporizer 40. The second mixed gas generated by the ammonia vaporizer 40 is fed into the gas separator. The gas separator removes water vapor from the second mixed gas and separates out ammonia.

[0058] Thus, by removing water vapor from the second mixture, the problems of water vapor entering the ammonia cracking unit affecting catalyst activity and water vapor entering the burner 10 affecting furnace combustion can be solved.

[0059] The ammonia storage unit 70 is connected to the mixed gas separator. The ammonia storage unit 70 buffers and stabilizes the ammonia obtained from the mixed gas separator, then divides it into a first ammonia stream and a second ammonia stream, and then delivers it to the cracking unit and the mixing unit 100.

[0060] Thus, by stabilizing the pressure of ammonia through the ammonia storage tank 70, the flow rate of ammonia supplied to the ammonia cracking unit and the mixing unit 100 can be stabilized.

[0061] In some embodiments, the output terminal of the ammonia storage tank 70 is provided with a flow regulating valve. The flow regulating valve can regulate the flow rate of the first ammonia stream and the second ammonia stream.

[0062] Thus, by adjusting the flow rates of the two ammonia streams, the flow rates can be adjusted in real time based on the furnace load, flame state, and nitrogen oxide concentration data, adapting to different furnace load and combustion stability requirements. When switching between high and low loads in the furnace, the flow rate of the first ammonia stream can be quickly adjusted to stabilize the flame. In the event of a malfunction in ammonia combustion system 1, the first ammonia stream can be cut off, preventing further hydrogen production through pyrolysis and enhancing the safety of ammonia combustion system 1.

[0063] In some embodiments, the ammonia cracking unit includes an ammonia heater 80 and an ammonia fixed-bed reactor 90.

[0064] The ammonia heater 80 is connected to the ammonia storage tank 70. The first stream of ammonia from the ammonia storage tank 70 is first fed into the ammonia heater 80 and heated to a preset catalytic temperature. The preset catalytic temperature is the activation temperature of the catalyst, and different catalysts have different preset catalytic temperatures. By heating the first stream of ammonia beforehand, the catalytic cracking reaction of the first stream of ammonia can proceed efficiently and stably.

[0065] Ammonia fixed-bed reactor 90 is connected to ammonia heater 80. The first stream of catalytically treated ammonia gas is fed into the catalyst-filled ammonia fixed-bed reactor 90. Under the action of the catalyst, the first stream of ammonia gas undergoes a partial cracking reaction, generating a first mixed gas containing hydrogen. The first mixed gas is then transported to mixing unit 100.

[0066] Thus, by combining the ammonia heater 80 and the ammonia fixed-bed reactor 90, a first mixed gas containing hydrogen can be prepared, solving the problem that ammonia is inherently unstable.

[0067] In some embodiments, the gas separator includes a first gas separator 50 and a second gas separator 60. The second gas mixture generated from the vaporization of the first ammonia-containing solution first enters the first separator to remove most of the first water vapor, resulting in a third gas mixture containing second water vapor. The second water vapor is a small amount of the first water vapor. The third gas mixture then enters the second separator for further removal of the second water vapor, yielding high-purity ammonia.

[0068] Thus, by performing coarse and fine separation on the second mixed gas, the water vapor content is gradually reduced. Compared with single-step separation, two-stage separation can improve the water vapor removal efficiency and solve the problem of pipeline blockage or corrosion caused by water vapor condensation in the ammonia cracking unit and mixing unit 100.

[0069] In some embodiments, a condenser 120 is provided at the input end of the first gas-mixing separator 50. The condenser 120 can condense the first water vapor into a first aqueous solution, which is then separated from the second gas-mixing mixture by the first gas-mixing separator 50.

[0070] Thus, by providing a condenser 120 at the input end of the first gas-mixing separator 50, the efficiency of the first gas-mixing separator 50 in separating the first water vapor can be improved.

[0071] Secondly, such as Figure 2 As shown, this application provides a method for controlling ammonia combustion, which is applied to the ammonia combustion system 1 provided in the first aspect embodiment of this application. The method includes the following steps: S100: Obtain temperature distribution information along the first direction within the ammonia combustion region, and determine the first target region where the ammonia combustion region is within the preset nitrogen suppression temperature range and the second target region where the ammonia combustion region is within the preset denitrification temperature range.

[0072] By acquiring temperature distribution information along the direction of large temperature change in the ammonia combustion zone, and combining this with the location of the temperature analysis information, the first target area of ​​the preset nitrogen suppression temperature range and the second target area of ​​the preset denitrification temperature range can be determined.

[0073] S200: Control the first injector to inject ammonia-containing gas into the first target area, and control the second injector to inject ammonia-containing solution into the second target area.

[0074] By controlling the injection position of the first ammonia-containing gas injector, the ammonia-containing gas can be injected into the first target area. By controlling the injection position of the second ammonia-containing solution injector, the ammonia-containing solution can be injected into the second target area.

[0075] Thus, by identifying the preset nitrogen suppression temperature range and the preset denitrification temperature range through temperature distribution information, and then injecting ammonia-containing gas and ammonia-containing solution into the first target area, the problem of ineffective nitrogen oxide concentration reduction caused by the deviation between the nitrogen suppression combustion temperature range and the denitrification temperature range can be solved. Simultaneously, through real-time monitoring of temperature distribution information, the ammonia combustion system 1 can promptly adjust the injection positions of the first target area, the first injector, and the second injector in response to real-time changes within the furnace, ensuring that the nitrogen oxide concentration in the ammonia combustion system 1 meets the standards.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. An ammonia combustion system, characterized in that, include: Furnace; Ammonia preparation apparatus, used to prepare ammonia-containing gas; A burner is disposed in the furnace chamber, the burner being used to inject the ammonia-containing gas into the furnace chamber, and the injection position of the burner is adjustable; A denitrification device is installed in the furnace, the denitrification device is used to spray an ammonia-containing solution, and the spraying position of the denitrification device is adjustable; A temperature detection device is used to acquire temperature distribution information along a first direction within the furnace. A control device is connected to the temperature detection device, the burner, and the denitrification device, respectively. The control device is used to control the injection position of the burner to inject the ammonia-containing gas into the first target area in the furnace within a preset nitrogen suppression temperature range, based on the temperature distribution information, and to control the injection position of the denitrification device to inject the ammonia-containing solution into the second target area in the furnace within a preset denitrification temperature range.

2. The ammonia combustion system according to claim 1, characterized in that, The ammonia combustion system also includes: A nitrogen oxide concentration monitoring device is used to acquire nitrogen oxide concentration data in the furnace. The nitrogen oxide concentration monitoring device is connected to the control device, which compares the nitrogen oxide concentration data with a preset nitrogen oxide concentration threshold and controls the start and stop of the denitrification device.

3. The ammonia combustion system according to claim 1, characterized in that, The control device has a pre-stored flame center temperature calculation model. Based on the temperature distribution information and the flame center temperature calculation model, the control device identifies the first target area and the second target area.

4. The ammonia combustion system according to claim 1, characterized in that, The preset nitrogen suppression temperature range is 900℃-1200℃; and / or The preset denitrification temperature range is 900℃-1100℃.

5. The ammonia combustion system according to claim 1, characterized in that, The ammonia preparation device includes: The ammonia preparation unit is used to prepare ammonia from ammonia water and output the first and second streams of ammonia. An ammonia cracking unit is used to catalytically crack the first path of ammonia to generate a first mixed gas, the first mixed gas containing hydrogen. A mixing unit is used to mix the first mixed gas with the second ammonia gas to form the ammonia-containing gas.

6. The ammonia combustion system according to claim 5, characterized in that, The ammonia preparation unit includes: An ammonia water supply device is used to store ammonia-containing solution and output a first ammonia-containing solution and a second ammonia-containing solution, the second ammonia-containing solution being input into the denitrification device; An ammonia vaporizer is connected to the ammonia vaporizer, which is used to vaporize the first ammonia-containing solution to generate a second mixed gas, the second mixed gas containing ammonia and first water vapor; A gas separator is connected to the ammonia vaporizer, and the gas separator is used to separate the ammonia from the second gas mixture; An ammonia storage device is connected to the mixed gas separator. The ammonia storage device is used to store the ammonia and divide the ammonia into a first ammonia stream and a second ammonia stream for output.

7. The ammonia combustion system according to claim 6, characterized in that, The output end of the ammonia storage device is equipped with a flow regulating valve, which is used to regulate the flow rates of the first and second ammonia streams.

8. The ammonia combustion system according to claim 5, characterized in that, The ammonia cracking unit includes: An ammonia heater is connected to the ammonia storage tank, and the ammonia heater is used to heat the first ammonia gas at a preset catalytic temperature; An ammonia fixed-bed reactor is connected to the ammonia heater. The ammonia fixed-bed reactor is used to catalytically crack the heated first-pass ammonia and generate a first mixed gas.

9. The ammonia combustion system according to claim 6, characterized in that, The gas-mixture separator includes: A first mixed gas separator is connected to the ammonia vaporizer. The first mixed gas separator is used to separate a third mixed gas from the second mixed gas. The third mixed gas contains the ammonia gas and the second water vapor. A second gas separator is connected to the first gas separator, and the second gas separator is used to separate the ammonia from the third gas mixture.

10. A method for controlling ammonia combustion, characterized in that, The ammonia combustion control method is implemented based on the ammonia combustion system according to any one of claims 2 to 9, and the method includes: Acquire temperature distribution information along the first direction within the ammonia combustion zone, and determine the first target zone where the ammonia combustion zone is within a preset nitrogen suppression temperature range and the second target zone where the ammonia combustion zone is within a preset denitrification temperature range; The first injector is controlled to inject ammonia-containing gas into the first target area, and the second injector is controlled to inject ammonia-containing solution into the second target area.

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