Ammonia Control Methods and Devices

Abstract

This disclosure provides an ammonia quantity control method and apparatus. The method includes: acquiring current boiler parameters of the coal-fired boiler; collecting nitrogen oxide parameters at the denitrification inlet of the denitrification system as a first nitrogen oxide parameter; collecting nitrogen oxide parameters at the denitrification outlet of the denitrification system as a second nitrogen oxide parameter; collecting nitrogen oxide parameters at the total exhaust outlet of the denitrification system as a third nitrogen oxide parameter; determining the current required ammonia quantity for the denitrification system based on at least one of the current boiler parameters, the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter; and injecting ammonia into the denitrification system according to the current required ammonia quantity. In this way, the ammonia injection quantity calculated by combining different parameters is obviously more accurate, improving the ammonia injection precision of the denitrification system and achieving automation, accuracy, reliability, and robustness of ammonia injection in the denitrification system.

Description

Technical Field

[0001] This disclosure relates to the field of industrial flue gas denitrification control, and in particular to the field of ammonia control technology. Background Technology

[0002] Currently, environmental protection requirements are becoming increasingly stringent, with higher standards for the quality of flue gas emitted by power plants and other factories. The concentration of nitrogen oxides (NOx) in the flue gas from coal-fired boilers and other industrial equipment must meet certain conditions before emissions can proceed; otherwise, air quality will be affected, causing environmental pollution. To reduce the concentration of NOx to a certain level, ammonia injection is required through a denitrification system. Specifically, after NOx and ammonia enter the denitrification system, they are converted into nitrogen and water under the action of a catalyst, thereby reducing the concentration of NOx. However, if this ammonia injection process is performed manually, it can result in either excessive or insufficient injection. Excessive injection can cause blockage of the air preheater in power plant boilers, while insufficient injection (insufficient NOx removal) will lead to failure to meet environmental standards. Therefore, automatic control with high precision, reliability, and robustness is required. Thus, how to accurately control the amount of ammonia injected has become an urgent problem to be solved. Summary of the Invention

[0003] This disclosure provides a method and apparatus for controlling ammonia levels.

[0004] According to a first aspect of this disclosure, a method for controlling ammonia levels is provided. The method includes:

[0005] Obtain the current boiler parameters of the coal-fired boiler;

[0006] The nitrogen oxide parameters at the denitrification inlet of the denitrification system are collected as the first nitrogen oxide parameter;

[0007] The nitrogen oxide parameters at the denitrification outlet of the denitrification system are collected as a second nitrogen oxide parameter;

[0008] The nitrogen oxide parameters of the total exhaust port of the denitrification system are collected as the third nitrogen oxide parameter;

[0009] The required ammonia amount for the denitrification system is determined based on at least one of the current boiler parameters, the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter.

[0010] Ammonia is injected into the denitrification system according to the current required ammonia amount.

[0011] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein determining the current required ammonia amount for the denitrification system based on at least one of the current boiler parameters, the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter includes:

[0012] Based on the current boiler parameters, determine the corresponding first target ammonia quantity;

[0013] Calculate the second target ammonia quantity based on the current boiler parameters, the first nitrogen oxide parameter, and the second nitrogen oxide parameter;

[0014] Calculate the third target ammonia quantity based on the current boiler parameters and the second nitrogen oxide parameters;

[0015] Calculate the fourth target ammonia amount based on the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter;

[0016] The first target ammonia amount, the second target ammonia amount, the third target ammonia amount, and the fourth target ammonia amount are weighted and summed to obtain the sum of ammonia amounts;

[0017] The sum of the ammonia amounts is compared with a preset minimum ammonia amount;

[0018] If the sum of the ammonia amounts is greater than or equal to the preset minimum ammonia amount, then the sum of the ammonia amounts is determined as the current ammonia amount required by the denitrification system;

[0019] If the sum of the ammonia amounts is less than the preset minimum ammonia amount, then the preset minimum ammonia amount is determined as the current ammonia amount required by the denitrification system.

[0020] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein determining the corresponding first target ammonia quantity based on the current boiler parameters includes:

[0021] Obtain historical boiler parameters;

[0022] Calculate the boiler parameter difference between the current boiler parameters and the historical boiler parameters;

[0023] The first target ammonia quantity is calculated based on the difference in the boiler parameters.

[0024] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein the current boiler parameters include the current furnace air volume of the boiler; the calculation of the second target ammonia quantity based on the current boiler parameters, the first nitrogen oxide parameter, and the second nitrogen oxide parameter includes:

[0025] Obtain the nitrogen oxide setpoint at the total exhaust port and the nitrogen oxide setpoint at the denitrification outlet;

[0026] Obtain the actual ammonia injection rate of the denitrification system;

[0027] Determine the start and stop times of the coal mill;

[0028] The second target ammonia quantity is calculated based on the current furnace air volume, the first nitrogen oxide parameter, the second nitrogen oxide parameter, the nitrogen oxide setpoint of the total exhaust port, the nitrogen oxide setpoint of the denitrification outlet, the actual ammonia injection quantity, and the start-up and shutdown times.

[0029] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein calculating the second target ammonia quantity based on the current furnace air volume, the first nitrogen oxide parameter, the second nitrogen oxide parameter, the nitrogen oxide setpoint of the total exhaust port, the nitrogen oxide setpoint of the denitrification outlet, the actual ammonia injection quantity, and the start-up / shutdown time includes:

[0030] Calculate the first preset ammonia amount based on the first nitrogen oxide parameter, the nitrogen oxide set value at the denitrification outlet, and the current furnace air volume;

[0031] The second preset ammonia quantity is calculated based on the second nitrogen oxide parameter, the nitrogen oxide set value at the denitrification outlet, and the current furnace air volume;

[0032] Determine the third preset ammonia quantity corresponding to the start / stop time;

[0033] Obtain historical theoretical ammonia injection volume;

[0034] The difference between the historical theoretical ammonia injection amount and the current actual ammonia injection amount is calculated and used as the fourth preset ammonia amount;

[0035] The first preset ammonia amount, the second preset ammonia amount, the third preset ammonia amount, and the fourth preset ammonia amount are weighted and summed to obtain the second target ammonia amount.

[0036] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein calculating the second preset ammonia quantity based on the second nitrogen oxide parameter, the nitrogen oxide setpoint at the denitrification outlet, and the current furnace air volume includes:

[0037] Every preset time interval, it is determined whether the second nitrogen oxide parameter is greater than the nitrogen oxide set value at the denitrification outlet;

[0038] If the second nitrogen oxide parameter is greater than the nitrogen oxide set value at the denitrification outlet and the second nitrogen oxide parameter continues to increase within the first preset time period, then the second preset ammonia amount is calculated based on the second nitrogen oxide parameter, the nitrogen oxide set value at the denitrification outlet, and the current furnace air volume.

[0039] or

[0040] Every preset time interval, it is determined whether the second nitrogen oxide parameter is less than the nitrogen oxide set value at the denitrification outlet;

[0041] If the second nitrogen oxide parameter is less than the nitrogen oxide set value at the denitrification outlet and the second nitrogen oxide parameter continues to decrease within the second preset time period, then the second preset ammonia quantity is calculated based on the second nitrogen oxide parameter, the nitrogen oxide set value at the denitrification outlet, and the current furnace air volume.

[0042] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein the current boiler parameters include the current furnace air volume, and the calculation of the third target ammonia quantity based on the current boiler parameters and the second nitrogen oxide parameter includes:

[0043] The nitrogen oxide setting value at the denitrification outlet is calculated based on the second nitrogen oxide parameter, the third nitrogen oxide parameter, and the nitrogen oxide setting value at the total exhaust port.

[0044] The third target ammonia quantity is calculated based on the second nitrogen oxide parameter, the nitrogen oxide setpoint at the denitrification outlet, and the current furnace air volume.

[0045] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein calculating the fourth target ammonia amount based on the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter includes:

[0046] Calculate the difference between the second nitrogen oxide parameter and the first preset nitrogen oxide parameter;

[0047] Determine whether the difference is greater than a preset nitrogen oxide threshold;

[0048] If the second nitrogen oxide parameter continues to increase within a third preset time period and the difference is greater than the preset nitrogen oxide threshold, then the first preset specified ammonia amount is increased.

[0049] The first preset ammonia amount is determined as the fourth target ammonia amount.

[0050] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein calculating the fourth target ammonia amount based on the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter includes:

[0051] Collect the current oxygen level at the main exhaust port;

[0052] Determine whether the current oxygen level is normal;

[0053] If the current oxygen level is normal, the total exhaust port of the denitrification system is not backflushed, and the third nitrogen oxide parameter is higher than the second preset nitrogen oxide parameter, then increase the second preset ammonia level.

[0054] The second preset ammonia amount is determined as the fourth target ammonia amount.

[0055] According to a second aspect of this disclosure, an ammonia quantity control device is provided. The device is suitable for a denitrification system, wherein a coal-fired boiler is connected upstream of the denitrification system. The coal-fired boiler is used to burn pulverized coal to generate flue gas and to introduce the flue gas into the denitrification system. The denitrification system is used to denitrify the flue gas. A coal mill is connected upstream of the coal-fired boiler to grind coal lumps into pulverized coal and to supply the pulverized coal to the coal-fired boiler. The device includes:

[0056] The acquisition module is used to acquire the current boiler parameters of the coal-fired boiler;

[0057] The first acquisition module is used to acquire the nitrogen oxide parameters at the denitrification inlet of the denitrification system as the first nitrogen oxide parameter;

[0058] The second acquisition module is used to acquire the nitrogen oxide parameters at the denitrification outlet of the denitrification system as the second nitrogen oxide parameters;

[0059] The third acquisition module is used to acquire the nitrogen oxide parameters of the total exhaust port of the denitrification system as the third nitrogen oxide parameter;

[0060] The determination module is used to determine the current ammonia amount required by the denitrification system based on at least one of the current boiler parameters, the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter;

[0061] The ammonia injection module is used to inject ammonia into the denitrification system according to the currently required ammonia amount.

[0062] According to a third aspect of this disclosure, an electronic device is provided. The electronic device includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the program to implement the method described above.

[0063] According to a fourth aspect of this disclosure, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the method according to a first aspect of this disclosure.

[0064] In this disclosure, by acquiring the current boiler parameters of the coal-fired boiler, the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter of the denitrification system, at least one of these parameters can be used for reasonable calculation. This allows for the accurate calculation of the current ammonia quantity required by the denitrification system by integrating multiple different parameters of the denitrification system and related equipment. Then, ammonia is automatically injected into the denitrification system according to the current required ammonia quantity. This avoids the need for manual calculation of the ammonia injection quantity, and the ammonia injection quantity calculated by integrating different parameters is obviously more accurate, improving the ammonia injection precision of the denitrification system and achieving automation, accuracy, reliability, and robustness of ammonia injection in the denitrification system.

[0065] It should be understood that the description in the Summary of the Invention is not intended to limit the key or essential features of the embodiments of this disclosure, nor is it intended to restrict the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0066] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. The drawings are provided for a better understanding of the invention and are not intended to limit the scope of this disclosure. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein:

[0067] Figure 1 A schematic diagram illustrating the connection relationship of a denitrification system according to an embodiment of the present disclosure is shown.

[0068] Figure 2 A flowchart of an ammonia quantity control method according to an embodiment of the present disclosure is shown;

[0069] Figure 3 A block diagram of an ammonia quantity control device according to an embodiment of the present disclosure is shown;

[0070] Figure 4 A block diagram of an exemplary electronic device capable of implementing embodiments of the present disclosure is shown. Detailed Implementation

[0071] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0072] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0073] Figure 2 A flowchart of an ammonia quantity control method 200 according to an embodiment of the present disclosure is shown. Method 200 is applicable to a denitrification system, the function of which is to: after ammonia injection, ensure that nitrogen oxides and ammonia are thoroughly mixed, and then, under the action of a catalyst, generate nitrogen gas and water, with the connection relationship as follows... Figure 1 As shown, a coal-fired boiler is connected upstream of the denitrification system. The coal-fired boiler is used to burn pulverized coal to generate flue gas, which is then introduced into the denitrification system. The denitrification system is used to denitrify the flue gas. A coal mill is connected upstream of the coal-fired boiler. The coal mill is used to grind coal lumps into pulverized coal and supply the pulverized coal to the coal-fired boiler. The method further includes:

[0074] Step 210: Obtain the current boiler parameters of the coal-fired boiler;

[0075] Current boiler parameters include, but are not limited to, the oxygen quantity, air volume, coal feed rate, and start / stop of the coal mill in coal-fired boilers.

[0076] Step 220: Collect the nitrogen oxide parameters (e.g., NOx concentration) at the denitrification inlet of the denitrification system as the first nitrogen oxide parameter; Figure 1 As shown, the denitrification inlet is the inlet of the catalyst layer in the denitrification system, which is used to allow flue gas and injected ammonia to enter the catalyst layer so that nitrogen oxides and ammonia in the flue gas can react under the action of the catalyst; the denitrification outlet is the outlet of the catalyst layer in the denitrification system, which is used to discharge the gas, liquid and unreacted residual nitrogen oxides or ammonia after the reaction; the total exhaust port is equivalent to the chimney outlet of the denitrification system, which is used to discharge the gas in the denitrification system at the end.

[0077] Step 230: Collect the nitrogen oxide parameters at the denitrification outlet of the denitrification system as the second nitrogen oxide parameter;

[0078] Step 240: Collect the nitrogen oxide parameters of the total exhaust port of the denitrification system as the third nitrogen oxide parameter;

[0079] Step 250: Determine the current required ammonia amount (such as ammonia concentration or mass) for the denitrification system based on at least one of the current boiler parameters, the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter.

[0080] Step 260: Inject ammonia into the denitrification system according to the currently required ammonia amount.

[0081] By acquiring the current boiler parameters of the coal-fired boiler, and the first, second, and third nitrogen oxide parameters of the denitrification system, at least one of these parameters can be used for reasonable calculation. This allows for the accurate calculation of the current ammonia requirement of the denitrification system by integrating multiple different parameters of the denitrification system and related equipment. Then, ammonia is automatically injected into the denitrification system according to the current required ammonia amount. This avoids the need for manual calculation of the ammonia injection amount, and the ammonia injection amount calculated by integrating different parameters is obviously more accurate, improving the ammonia injection precision of the denitrification system and achieving automation, accuracy, reliability, and robustness of ammonia injection in the denitrification system.

[0082] In some embodiments, determining the current required ammonia amount for the denitrification system based on at least one of the current boiler parameters, the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter includes:

[0083] Based on the current boiler parameters, determine the corresponding first target ammonia quantity;

[0084] Calculate the second target ammonia quantity based on the current boiler parameters, the first nitrogen oxide parameter, and the second nitrogen oxide parameter;

[0085] Calculate the third target ammonia quantity based on the current boiler parameters and the second nitrogen oxide parameters;

[0086] Calculate the fourth target ammonia amount based on the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter;

[0087] The first target ammonia amount, the second target ammonia amount, the third target ammonia amount, and the fourth target ammonia amount are weighted and summed to obtain the sum of ammonia amounts;

[0088] The sum of the ammonia amounts is compared with a preset minimum ammonia amount;

[0089] If the sum of the ammonia amounts is greater than or equal to the preset minimum ammonia amount, then the sum of the ammonia amounts is determined as the current ammonia amount required by the denitrification system;

[0090] If the sum of the ammonia amounts is less than the preset minimum ammonia amount, then the preset minimum ammonia amount is determined as the current ammonia amount required by the denitrification system.

[0091] After calculating the first, second, third, and fourth target ammonia amounts, the system automatically performs a weighted sum of these amounts to obtain the total ammonia amount. This sum is then compared to a preset minimum ammonia amount. If the sum is greater than or equal to the preset minimum ammonia amount, it indicates that the sum is appropriate, and the sum is determined as the current ammonia amount required by the denitrification system. If the sum is less than the preset minimum ammonia amount, it indicates that using the sum as the current required ammonia amount is inappropriate, potentially leading to insufficient ammonia injection in the denitrification system and failure to meet environmental standards. Therefore, the preset minimum ammonia amount can be automatically determined as the current ammonia amount required by the denitrification system, ensuring that the ammonia injection amount is both sufficient and appropriate.

[0092] In some embodiments, determining the corresponding first target ammonia quantity based on the current boiler parameters includes:

[0093] Obtain historical boiler parameters; these historical boiler parameters can be boiler parameters at a certain historical moment or the average value of boiler parameters over a certain historical period.

[0094] Calculate the boiler parameter difference between the current boiler parameters and the historical boiler parameters;

[0095] The first target ammonia quantity is calculated based on the difference in the boiler parameters.

[0096] By calculating the difference between the current boiler parameters and the historical boiler parameters, the first target ammonia quantity can be automatically calculated based on this difference, thereby accurately calculating the first target ammonia quantity through the change in boiler parameters.

[0097] For example: if the coal feed rate of the coal boiler decreases by more than 9 kg compared to the previous 20 seconds, then the ammonia feed rate will increase by 20 kg within 10 seconds, and then decrease by 0.1 kg per second until it reaches 0.

[0098] formula:

[0099] If the coal feed rate decreases and is more than 9% lower than the data from 20 seconds ago...

[0100] The ammonia amount is increased by 20 kg over a 10-second delay, and then decreased by 0.1 kg per second until it reaches 0.

[0101] In some embodiments, the current boiler parameters include the current furnace air volume of the boiler; calculating the second target ammonia quantity based on the current boiler parameters, the first nitrogen oxide parameter, and the second nitrogen oxide parameter includes:

[0102] Obtain the nitrogen oxide setpoint at the total exhaust port and the nitrogen oxide setpoint at the denitrification outlet;

[0103] Obtain the actual ammonia injection rate of the denitrification system;

[0104] Determine the start and stop times of the coal mill;

[0105] The second target ammonia quantity is calculated based on the current furnace air volume, the first nitrogen oxide parameter, the second nitrogen oxide parameter, the nitrogen oxide setpoint of the total exhaust port, the nitrogen oxide setpoint of the denitrification outlet, the actual ammonia injection quantity, and the start-up and shutdown times.

[0106] By acquiring the nitrogen oxide setpoint at the total exhaust port, the nitrogen oxide setpoint at the denitrification outlet, the actual ammonia injection rate of the denitrification system, and the start-up and shutdown times of the coal mill, the second target ammonia quantity can be accurately calculated by combining these data with the current furnace air volume, the first nitrogen oxide parameter, and the second nitrogen oxide parameter, thereby improving the accuracy of the second target ammonia quantity.

[0107] In some embodiments, calculating the second target ammonia quantity based on the current furnace air volume, the first nitrogen oxide parameter, the second nitrogen oxide parameter, the nitrogen oxide setpoint of the total exhaust port, the nitrogen oxide setpoint of the denitrification outlet, the actual ammonia injection quantity, and the start-up / shutdown time includes:

[0108] Calculate the first preset ammonia amount based on the first nitrogen oxide parameter, the nitrogen oxide set value at the denitrification outlet, and the current furnace air volume;

[0109] For example: First preset ammonia quantity (mass of ammonia) = (inlet NOx concentration - outlet NOx concentration set value) * total furnace air volume * conversion factor. This conversion factor is the conversion factor between the concentration of nitrogen oxides (NOx) and the mass of ammonia, used to characterize the relationship between the concentration of nitrogen oxides and the mass of ammonia. The conversion factor = (17 / 46) / 0.283 / 1000 / 1.293.

[0110] The second preset ammonia quantity is calculated based on the second nitrogen oxide parameter, the nitrogen oxide set value at the denitrification outlet, and the current furnace air volume;

[0111] The second preset ammonia quantity = ∑(outlet NOx concentration - outlet NOx concentration setpoint) × total furnace air volume × (17 ÷ 46) ÷ 0.283 ÷ 1000 ÷ 1.293. This second preset ammonia quantity is accumulated once every preset time period. This outlet is the denitrification outlet.

[0112] Determine the third preset ammonia quantity corresponding to the start / stop time;

[0113] When the coal mill starts, coal is added to the coal boiler, which increases the concentration of nitrogen oxides. Therefore, after the coal mill starts, the third preset amount of ammonia needs to be added to the denitrification system after a 2-minute delay. When the coal mill stops, there is no coal in the coal mill and very little coal in the coal boiler, but the air volume in the coal boiler is still relatively high, causing the mixing of coal and air to become uneven. As a result, the concentration of nitrogen oxides also increases. Therefore, after the coal mill stops, the third preset amount of ammonia needs to be added to the denitrification system after a 2-minute delay.

[0114] Obtain historical theoretical ammonia injection volume;

[0115] The difference between the historical theoretical ammonia injection amount and the current actual ammonia injection amount is calculated and used as the fourth preset ammonia amount;

[0116] The historical theoretical ammonia injection volume can be the theoretical ammonia injection volume during the process of manually estimating the ammonia injection volume (i.e., non-automatic calculation of the ammonia injection volume).

[0117] Using the difference between the historical theoretical ammonia injection amount and the current actual ammonia injection amount as the fourth preset ammonia amount ensures that the theoretical ammonia injection amount tracks the actual ammonia injection amount, and ensures that the calculated theoretical ammonia injection amount can track the actual required ammonia amount in real time, that is, ensures that the theoretical ammonia injection amount can meet the actual ammonia requirement.

[0118] The first preset ammonia amount, the second preset ammonia amount, the third preset ammonia amount, and the fourth preset ammonia amount are weighted and summed to obtain the second target ammonia amount.

[0119] By combining different parameters to calculate the first, second, third, and fourth preset ammonia amounts, the four ammonia amounts can be automatically weighted and summed to obtain the accurate second target ammonia amount.

[0120] In some embodiments, calculating the second preset ammonia quantity based on the second nitrogen oxide parameter, the nitrogen oxide setpoint at the denitrification outlet, and the current furnace air volume includes:

[0121] Every preset time interval, it is determined whether the second nitrogen oxide parameter is greater than the nitrogen oxide set value at the denitrification outlet;

[0122] If the second nitrogen oxide parameter is greater than the nitrogen oxide set value at the denitrification outlet and the second nitrogen oxide parameter continues to increase within the first preset time period, then the second preset ammonia quantity is calculated based on the second nitrogen oxide parameter, the nitrogen oxide set value at the denitrification outlet, and the current furnace air volume.

[0123] If the second nitrogen oxide parameter is greater than the nitrogen oxide setting value at the denitrification outlet and continues to increase at preset time intervals, it indicates that the nitrogen oxide parameter at the denitrification outlet is too high and has not yet met the environmental protection standards, and the amount of ammonia injected is too small. Therefore, the second preset ammonia amount can be accurately calculated by combining the nitrogen oxide setting value at the denitrification outlet and the current furnace air volume, so that the nitrogen oxide parameter requirements at the denitrification outlet are fully considered when injecting ammonia.

[0124] or

[0125] In some embodiments, calculating the second preset ammonia quantity based on the second nitrogen oxide parameter, the nitrogen oxide setpoint at the denitrification outlet, and the current furnace air volume includes:

[0126] Every preset time interval, it is determined whether the second nitrogen oxide parameter is less than the nitrogen oxide set value at the denitrification outlet;

[0127] If the second nitrogen oxide parameter is less than the nitrogen oxide set value at the denitrification outlet and the second nitrogen oxide parameter continues to decrease within the second preset time period, then the second preset ammonia quantity is calculated based on the second nitrogen oxide parameter, the nitrogen oxide set value at the denitrification outlet, and the current furnace air volume.

[0128] If the second nitrogen oxide parameter is less than the nitrogen oxide setting value at the denitrification outlet and continues to decrease at preset time intervals, it indicates that the nitrogen oxide parameter at the denitrification outlet is too low and too much ammonia is being injected. Too much ammonia injection may cause blockage of the boiler air preheater. Therefore, the second preset ammonia amount can be accurately calculated by combining the second nitrogen oxide parameter, the nitrogen oxide setting value at the denitrification outlet, and the current furnace air volume, so that the nitrogen oxide parameter requirements at the denitrification outlet are fully considered when injecting ammonia.

[0129] In some embodiments, the current boiler parameters include the current furnace air volume, and the calculation of the third target ammonia quantity based on the current boiler parameters and the second nitrogen oxide parameter includes:

[0130] The nitrogen oxide setting value at the denitrification outlet is calculated based on the second nitrogen oxide parameter, the third nitrogen oxide parameter, and the nitrogen oxide setting value at the total exhaust port.

[0131] The third target ammonia quantity is calculated based on the second nitrogen oxide parameter, the nitrogen oxide setpoint at the denitrification outlet, and the current furnace airflow. The denitrification system may have multiple denitrification outlets, such as... Figure 2 The diagram shows denitrification outlet A and denitrification outlet B.

[0132] Based on the second nitrogen oxide parameter, the third nitrogen oxide parameter, and the nitrogen oxide setting value of the total exhaust port, the nitrogen oxide setting value of the denitrification outlet can be accurately calculated. Then, based on the second nitrogen oxide parameter, the nitrogen oxide setting value of the denitrification outlet, and the current furnace air volume, the third target ammonia quantity can be accurately calculated.

[0133] The setpoint for nitrogen oxides at the denitrification outlet = ((Average NOx concentration at the denitrification outlet over a recent period - Average NOx concentration at the total exhaust outlet over a recent period + Setpoint for nitrogen oxides at the total exhaust outlet) + (Average NOx concentration at the denitrification outlet over a recent period - Average NOx concentration at the total exhaust outlet over a recent period + Setpoint for nitrogen oxides at the total exhaust outlet)) / 2.

[0134] The NOx concentration at the A / B denitrification outlet in the most recent period is the second nitrogen oxide parameter; the nitrogen oxide setpoint at the total exhaust port is the nitrogen oxide setpoint at the total exhaust port.

[0135] The third target ammonia quantity = (NOx concentration at the denitrification outlet - NOx concentration setpoint at the denitrification outlet) * total furnace air volume * conversion factor. Conversion factor = (17 ÷ 46) ÷ 0.283 ÷ 1000 ÷ 1.293.

[0136] In some embodiments, calculating the fourth target ammonia content based on the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter includes:

[0137] Calculate the difference between the second nitrogen oxide parameter and the first preset nitrogen oxide parameter;

[0138] Determine whether the difference is greater than a preset nitrogen oxide threshold;

[0139] If the second nitrogen oxide parameter continues to increase within a third preset time period and the difference is greater than the preset nitrogen oxide threshold, then the first preset specified ammonia amount is increased.

[0140] The first preset ammonia amount is determined as the fourth target ammonia amount.

[0141] If the second nitrogen oxide parameter continues to increase within the third preset time period and the difference is greater than the preset nitrogen oxide threshold, it indicates that the nitrogen oxide concentration at the denitrification outlet continues to increase and is always greater than the set value. Therefore, it is necessary to increase the amount of ammonia to reduce the concentration of nitrogen oxides. Thus, the first preset specified ammonia amount can be increased, and the first preset specified ammonia amount is automatically determined as the fourth target ammonia amount.

[0142] In some embodiments, calculating the fourth target ammonia content based on the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter includes:

[0143] Collect the current oxygen level at the main exhaust port;

[0144] Determine whether the current oxygen level is normal;

[0145] If the current oxygen level is normal, the total exhaust port of the denitrification system is not backflushed, and the third nitrogen oxide parameter is higher than the second preset nitrogen oxide parameter, then increase the second preset ammonia level.

[0146] Under normal circumstances, the residual gas in the main exhaust port needs to be sucked out and disposed of. However, to avoid blockage of the main exhaust port, it is necessary to backflush the main exhaust port periodically. In addition, the gas discharged from the main exhaust port contains some oxygen. When the denitrification system is working normally, the oxygen level in the main exhaust port is also normal. Therefore, in order to ensure the accuracy of the ammonia level, the ammonia level needs to be determined again when the main exhaust port is not backflushed and the current oxygen level is normal. Specifically, if the third nitrogen oxide parameter is higher than the second preset nitrogen oxide parameter at this time, it means that the nitrogen oxide concentration in the main exhaust port of the denitrification system is too high. Therefore, it is necessary to increase the second preset ammonia level and automatically determine the second preset ammonia level as the fourth target ammonia level.

[0147] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this disclosure is not limited to the described order of actions, because according to this disclosure, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this disclosure.

[0148] The above is an introduction to the method embodiments. The following describes the solution described in this disclosure further through device embodiments.

[0149] Figure 3 A block diagram of an ammonia quantity control device 300 according to an embodiment of the present disclosure is shown. Figure 3 As shown, the device 300 includes:

[0150] The acquisition module 310 is used to acquire the current boiler parameters of the coal-fired boiler;

[0151] The first acquisition module 320 is used to acquire the nitrogen oxide parameters at the denitrification inlet of the denitrification system as the first nitrogen oxide parameter;

[0152] The second acquisition module 330 is used to acquire the nitrogen oxide parameters at the denitrification outlet of the denitrification system as the second nitrogen oxide parameters;

[0153] The third acquisition module 340 is used to acquire the nitrogen oxide parameters of the total exhaust port of the denitrification system as the third nitrogen oxide parameter;

[0154] The determining module 350 is used to determine the current required ammonia amount of the denitrification system based on at least one of the current boiler parameters, the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter;

[0155] The ammonia injection module 360 ​​is used to inject ammonia into the denitrification system according to the currently required ammonia amount.

[0156] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the described module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0157] According to embodiments of the present disclosure, the present disclosure also provides an electronic device and a non-transitory computer-readable storage medium storing computer instructions.

[0158] Figure 4 A schematic block diagram of an electronic device 800 that can be used to implement embodiments of the present disclosure is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0159] Device 800 includes a computing unit 801, which can perform various appropriate actions and processes based on a computer program stored in read-only memory (ROM) 802 or a computer program loaded from storage unit 808 into random access memory (RAM) 803. RAM 803 may also store various programs and data required for the operation of device 800. The computing unit 801, ROM 802, and RAM 803 are interconnected via bus 804. Input / output (I / O) interface 805 is also connected to bus 804.

[0160] Multiple components in device 800 are connected to I / O interface 805, including: input unit 806, such as keyboard, mouse, etc.; output unit 807, such as various types of monitors, speakers, etc.; storage unit 808, such as disk, optical disk, etc.; and communication unit 809, such as network card, modem, wireless transceiver, etc. Communication unit 809 allows device 800 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0161] The computing unit 801 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 801 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 801 performs the various methods and processes described above, such as method 100. For example, in some embodiments, method 100 may be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 808. In some embodiments, part or all of the computer program may be loaded and / or installed on device 800 via ROM 802 and / or communication unit 809. When the computer program is loaded into RAM 803 and executed by the computing unit 801, one or more steps of method 100 described above may be performed. Alternatively, in other embodiments, the computing unit 801 may be configured to perform method 100 by any other suitable means (e.g., by means of firmware).

[0162] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0163] The program code used to implement the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0164] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0165] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0166] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as a data server), or computing systems that include middleware components (e.g., an application server), or computing systems that include frontend components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with embodiments of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., a communication network). Examples of communication networks include local area networks (LANs), wide area networks (WANs), and the Internet.

[0167] Computing systems can include clients and servers. Clients and servers are generally located far apart and typically interact via communication networks. Client-server relationships are created by computer programs running on the respective computers and having a client-server relationship with each other. Servers can be cloud servers, servers in distributed systems, or servers incorporating blockchain technology.

[0168] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this is not limited herein.

[0169] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method for controlling ammonia levels, characterized in that, The method is applicable to a denitrification system, wherein a coal-fired boiler is connected upstream of the denitrification system. The coal-fired boiler is used to burn pulverized coal to generate flue gas and introduce the flue gas into the denitrification system. The denitrification system is used to denitrify the flue gas. A coal mill is connected upstream of the coal-fired boiler. The coal mill is used to grind coal lumps into pulverized coal and supply the pulverized coal to the coal-fired boiler. The method further includes: Obtain the current boiler parameters of the coal-fired boiler; The nitrogen oxide parameters at the denitrification inlet of the denitrification system are collected as the first nitrogen oxide parameter; The nitrogen oxide parameters at the denitrification outlet of the denitrification system are collected as a second nitrogen oxide parameter; The nitrogen oxide parameters of the total exhaust port of the denitrification system are collected as the third nitrogen oxide parameter; The required ammonia amount for the denitrification system is determined based on at least one of the current boiler parameters, the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter. Ammonia is injected into the denitrification system according to the currently required ammonia amount; Determining the current required ammonia amount for the denitrification system based on at least one of the current boiler parameters, the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter includes: Based on the current boiler parameters, determine the corresponding first target ammonia quantity; Calculate the second target ammonia quantity based on the current boiler parameters, the first nitrogen oxide parameter, and the second nitrogen oxide parameter; Calculate the third target ammonia quantity based on the current boiler parameters and the second nitrogen oxide parameters; Calculate the fourth target ammonia amount based on the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter; The first target ammonia amount, the second target ammonia amount, the third target ammonia amount, and the fourth target ammonia amount are weighted and summed to obtain the sum of ammonia amounts; The sum of the ammonia amounts is compared with a preset minimum ammonia amount; If the sum of the ammonia amounts is greater than or equal to the preset minimum ammonia amount, then the sum of the ammonia amounts is determined as the current ammonia amount required by the denitrification system; If the sum of the ammonia amounts is less than the preset minimum ammonia amount, then the preset minimum ammonia amount is determined as the current ammonia amount required by the denitrification system.

2. The method as described in claim 1, characterized in that, The step of determining the corresponding first target ammonia quantity based on the current boiler parameters includes: Obtain historical boiler parameters; Calculate the boiler parameter difference between the current boiler parameters and the historical boiler parameters; The first target ammonia quantity is calculated based on the difference in the boiler parameters.

3. The method as described in claim 1, characterized in that, The current boiler parameters include the current furnace air volume of the boiler; The step of calculating the second target ammonia quantity based on the current boiler parameters, the first nitrogen oxide parameter, and the second nitrogen oxide parameter includes: Obtain the nitrogen oxide setpoint at the total exhaust port and the nitrogen oxide setpoint at the denitrification outlet; Obtain the actual ammonia injection rate of the denitrification system; Determine the start and stop times of the coal mill; The second target ammonia quantity is calculated based on the current furnace air volume, the first nitrogen oxide parameter, the second nitrogen oxide parameter, the nitrogen oxide setpoint of the total exhaust port, the nitrogen oxide setpoint of the denitrification outlet, the actual ammonia injection quantity, and the start-up and shutdown times.

4. The method as described in claim 3, characterized in that, The calculation of the second target ammonia quantity based on the current furnace air volume, the first nitrogen oxide parameter, the second nitrogen oxide parameter, the nitrogen oxide setpoint of the total exhaust port, the nitrogen oxide setpoint of the denitrification outlet, the actual ammonia injection quantity, and the start-up and shutdown times includes: Calculate the first preset ammonia amount based on the first nitrogen oxide parameter, the nitrogen oxide set value at the denitrification outlet, and the current furnace air volume; The second preset ammonia quantity is calculated based on the second nitrogen oxide parameter, the nitrogen oxide set value at the denitrification outlet, and the current furnace air volume; Determine the third preset ammonia quantity corresponding to the start / stop time; Obtain historical theoretical ammonia injection volume; The difference between the historical theoretical ammonia injection amount and the current actual ammonia injection amount is calculated and used as the fourth preset ammonia amount; The first preset ammonia amount, the second preset ammonia amount, the third preset ammonia amount, and the fourth preset ammonia amount are weighted and summed to obtain the second target ammonia amount.

5. The method as described in claim 4, characterized in that, The step of calculating the second preset ammonia quantity based on the second nitrogen oxide parameter, the nitrogen oxide setpoint at the denitrification outlet, and the current furnace air volume includes: Every preset time interval, it is determined whether the second nitrogen oxide parameter is greater than the nitrogen oxide set value at the denitrification outlet; If the second nitrogen oxide parameter is greater than the nitrogen oxide set value at the denitrification outlet and the second nitrogen oxide parameter continues to increase within the first preset time period, then the second preset ammonia amount is calculated based on the second nitrogen oxide parameter, the nitrogen oxide set value at the denitrification outlet, and the current furnace air volume. or Every preset time interval, it is determined whether the second nitrogen oxide parameter is less than the nitrogen oxide set value at the denitrification outlet; If the second nitrogen oxide parameter is less than the nitrogen oxide set value at the denitrification outlet and the second nitrogen oxide parameter continues to decrease within the second preset time period, then the second preset ammonia quantity is calculated based on the second nitrogen oxide parameter, the nitrogen oxide set value at the denitrification outlet, and the current furnace air volume.

6. The method as described in claim 1, characterized in that, The current boiler parameters include the current furnace air volume. The calculation of the third target ammonia quantity based on the current boiler parameters and the second nitrogen oxide parameter includes: The nitrogen oxide setting value at the denitrification outlet is calculated based on the second nitrogen oxide parameter, the third nitrogen oxide parameter, and the nitrogen oxide setting value at the total exhaust port. The third target ammonia quantity is calculated based on the second nitrogen oxide parameter, the nitrogen oxide setpoint at the denitrification outlet, and the current furnace air volume.

7. The method as described in claim 1, characterized in that, The step of calculating the fourth target ammonia content based on the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter includes: Calculate the difference between the second nitrogen oxide parameter and the first preset nitrogen oxide parameter; Determine whether the difference is greater than a preset nitrogen oxide threshold; If the second nitrogen oxide parameter continues to increase within a third preset time period and the difference is greater than the preset nitrogen oxide threshold, then the first preset specified ammonia amount is increased. The first preset ammonia amount is determined as the fourth target ammonia amount.

8. The method as described in claim 1, characterized in that, The step of calculating the fourth target ammonia content based on the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter includes: Collect the current oxygen level at the main exhaust port; Determine whether the current oxygen level is normal; If the current oxygen level is normal, the total exhaust port of the denitrification system is not backflushed, and the third nitrogen oxide parameter is higher than the second preset nitrogen oxide parameter, then the second preset ammonia level is increased. The second preset ammonia amount is determined as the fourth target ammonia amount.

9. An ammonia quantity control device, characterized in that, The device is suitable for a denitrification system, wherein a coal-fired boiler is connected upstream of the denitrification system. The coal-fired boiler is used to burn pulverized coal to generate flue gas and introduce the flue gas into the denitrification system. The denitrification system is used to denitrify the flue gas. A coal mill is connected upstream of the coal-fired boiler. The coal mill is used to grind coal lumps into pulverized coal and supply the pulverized coal to the coal-fired boiler. The device includes: The acquisition module is used to acquire the current boiler parameters of the coal-fired boiler; The first acquisition module is used to acquire the nitrogen oxide parameters at the denitrification inlet of the denitrification system as the first nitrogen oxide parameter; The second acquisition module is used to acquire the nitrogen oxide parameters at the denitrification outlet of the denitrification system as the second nitrogen oxide parameters; The third acquisition module is used to acquire the nitrogen oxide parameters of the total exhaust port of the denitrification system as the third nitrogen oxide parameter; The determination module is used to determine the current ammonia amount required by the denitrification system based on at least one of the current boiler parameters, the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter; The ammonia injection module is used to inject ammonia into the denitrification system according to the currently required ammonia amount; The determining module is specifically used for: Based on the current boiler parameters, determine the corresponding first target ammonia quantity; Calculate the second target ammonia quantity based on the current boiler parameters, the first nitrogen oxide parameter, and the second nitrogen oxide parameter; Calculate the third target ammonia quantity based on the current boiler parameters and the second nitrogen oxide parameters; Calculate the fourth target ammonia amount based on the first nitrogen oxide parameter, the second nitrogen oxide parameter, and the third nitrogen oxide parameter; The first target ammonia amount, the second target ammonia amount, the third target ammonia amount, and the fourth target ammonia amount are weighted and summed to obtain the sum of ammonia amounts; The sum of the ammonia amounts is compared with a preset minimum ammonia amount; If the sum of the ammonia amounts is greater than or equal to the preset minimum ammonia amount, then the sum of the ammonia amounts is determined as the current ammonia amount required by the denitrification system; If the sum of the ammonia amounts is less than the preset minimum ammonia amount, then the preset minimum ammonia amount is determined as the current ammonia amount required by the denitrification system.

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