Method for controlling desulfurization and denitrification ammonia spraying amount of active coke

Abstract

The invention belongs to the technical field of flue gas desulfurization and denitrification, and particularly relates to a method for controlling the desulfurization and denitrification ammonia injection amount of active coke. The invention provides a method for controlling the ammonia spraying amount of active coke desulfurization and denitrification. The method comprises the following steps: calculating the amount of ammonia adsorbed by active coke discharged from an active coke desulfurization and denitrification reaction tower in a reference period; calculating the content ratio of ammonia in the active coke discharged from the active coke desulfurization and denitrification reaction tower; calculating the total amount of ammonia adsorbed by active coke in the reaction tower; calculating the total amount of ammonia adsorbed by active coke in the reaction tower in the ammonia water flow adjusting period; calculating the adjustment flow of ammonia water according to the difference between the reference period and the total amount of ammonia adsorbed by active coke of the reaction tower in the ammonia water flow adjustment period, and further determining the flow of the adjusted ammonia water. According to the control method for the active coke desulfurization and denitrification ammonia injection amount, the concentration fluctuation of NOx at an outlet is small, and waste of ammonia water is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of flue gas desulfurization and denitrification, and particularly relates to a method for controlling the amount of ammonia sprayed during desulfurization and denitrification of activated coke. Background Art

[0002] It is generally believed that the more ammonia adsorbed on the surface of activated coke, the more favorable it is for NO x Compared with other denitrification technologies, the activated coke denitrification system is huge and can be loaded with thousands or even tens of thousands of tons of activated coke. Ammonia will enter the activated coke bed along with the desulfurized flue gas. As the amount of ammonia adsorbed by the activated coke increases, the denitrification reaction rate increases, achieving NO x The ammonia adsorbed by activated coke will be continuously removed by NO in the flue gas. x The activated coke will also re-absorb the newly injected ammonia after consumption. Since the total amount of ammonia adsorbed by the activated coke bed is large, adjusting the ammonia flow rate in a short time will not have a significant impact on the total amount of ammonia in the activated coke bed. Generally, the adjustment of the ammonia flow rate has an obvious lag in the denitrification reaction. Only when the total amount of accumulated ammonia changes will it affect NO x of removal.

[0003] The existing technologies for controlling the amount of ammonia injected into activated coke are all based on real-time online detection data. The amount of ammonia injected is calculated theoretically, which places high demands on the accuracy and timeliness of the online detection data. Therefore, high-performance detection equipment is required and daily high-standard maintenance is also required. However, the theoretical amount of ammonia injected calculated in actual production is still quite different from the actual amount of ammonia required, because the denitrification effect is also affected by the adsorbed ammonia in the activated coke in the system. If the adsorbed ammonia in the activated coke in the system is small, even if the amount of ammonia injected is adjusted to the maximum value, NOx cannot be achieved in a short time. x The system contains a lot of adsorbed ammonia in the activated coke, so even if the ammonia injection amount is adjusted to 0, NO removal can still be achieved in a short time. x Therefore, the existing technology does not consider the effect of ammonia adsorption on denitrification by the activated coke bed, and requires high accuracy and large error in online detection equipment, resulting in high NO x Large fluctuations in concentration and large amounts of excess ammonia. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problem that the prior art does not consider the effect of ammonia adsorption on denitrification by the activated coke bed, and has high requirements on the accuracy of the online detection equipment, large errors, and the outlet NO x The defects of large concentration fluctuation and excess ammonia water are eliminated, so as to provide a method for controlling the amount of ammonia injection for activated coke desulfurization and denitrification.

[0005] To this end, the present invention provides the following technical solutions.

[0006] The present invention provides a method for controlling the amount of ammonia sprayed during desulfurization and denitrification of activated coke, comprising the following steps:

[0007] (1) Selecting activated coke desulfurization and denitrification reaction tower to stabilize NO emissions x The time period is taken as the reference period, and the ammonia adsorbed by the activated coke discharged from the activated coke desulfurization and denitration reaction tower during the reference period is absorbed by the sulfur-rich flue gas washing water to obtain the ammonia-rich washing water, and the amount of ammonia adsorbed by the activated coke discharged from the activated coke desulfurization and denitration reaction tower during the reference period is calculated according to the discharge flow rate of the sulfur-rich flue gas washing water and the ammonia content in the ammonia-rich washing water;

[0008] The base period is selected from the outlet of the activated coke desulfurization and denitrification reaction tower to emit stable NO x Any time period, and the NO emitted during this time period x If the emission standards are met, there is no limit on the length of this time period;

[0009] The value of the discharge flow rate of the sulfur-rich flue gas scrubbing water is not limited and can be selected according to the common knowledge of different processes in this field;

[0010] (2) calculating the proportion of ammonia content in the activated coke discharged from the activated coke desulfurization and denitrification reaction tower according to the amount of ammonia adsorbed by the activated coke discharged from the activated coke desulfurization and denitrification reaction tower and the circulation rate of the activated coke during the reference period;

[0011] (3) calculating the total amount of ammonia adsorbed by the activated coke in the desulfurization and denitration reaction tower according to the amount of ammonia adsorbed by the activated coke discharged from the desulfurization and denitration reaction tower during the reference period and the proportion of ammonia content in the activated coke discharged from the desulfurization and denitration reaction tower;

[0012] The step (3) refers to obtaining the total amount of ammonia adsorbed by the active coke in the reaction tower according to equation 3 by obtaining the proportion of ammonia content in the active coke discharged from the activated coke desulfurization and denitration reaction tower and the amount of ammonia adsorbed by the active coke discharged from the activated coke desulfurization and denitration reaction tower. It should be noted that the amount of ammonia adsorbed by the active coke discharged from the activated coke desulfurization and denitration reaction tower refers to the adsorbed ammonia contained in the active coke at the bottom of the reaction tower. The total amount of ammonia adsorbed by all active cokes in the reaction tower is calculated according to equation 3, that is, the total amount of ammonia adsorbed by the active coke in the reaction tower. Figure 1 It is a schematic diagram of a reaction tower including a constant ammonia content zone and a variable ammonia content zone, indicating that there are a variable zone and a constant zone in the ammonia content of the activated coke in the reaction tower.

[0013] (4) determining the ammonia flow adjustment period during the desulfurization and denitrification reaction of the activated coke, and calculating the total amount of ammonia adsorbed by the activated coke in the reaction tower during the ammonia flow adjustment period according to the method for calculating the total amount of ammonia adsorbed by the activated coke in the reaction tower during the base period in steps (1) to (3);

[0014] The step (4) means that there is an ammonia flow adjustment period in the activated coke desulfurization and denitrification process, and the ammonia flow adjustment period is determined by those skilled in the art according to the known knowledge. The activated coke desulfurization and denitrification process is compared with the reference period. The total amount of nitrogen adsorbed by the activated coke in the activated coke desulfurization and denitrification reaction tower remains basically unchanged. With reference to the total amount of ammonia adsorbed by the activated coke in the reaction tower in the reference period, the ammonia flow adjustment period is determined using the relational formula 4 to reduce the outlet NO x Fluctuation of emission concentration overcomes the NO caused by the existing technology not considering the effect of total ammonia changes in the activated coke system on denitrification. x The emission fluctuates greatly and the ammonia flow adjustment has the defect of lag.

[0015] (5) Calculating the adjusted flow rate of ammonia water according to the difference between the total amount of ammonia adsorbed by the active coke in the reaction tower during the base period and the ammonia water flow rate adjustment period, and then determining the flow rate of the ammonia water after adjustment.

[0016] In an optional embodiment, the calculation formula for the amount of ammonia adsorbed by the activated coke discharged from the activated coke desulfurization and denitrification reaction tower during the reference period is as follows:

[0017] AC NH =V 水 ×NH 水 ×10 -6 Relation 1

[0018] Among them, AC NH V is the amount of ammonia adsorbed by the activated coke discharged from the activated coke desulfurization and denitrification reaction tower during the reference period; 水 is the discharge flow of sulfur-rich flue gas scrubbing water; NH 水 is the ammonia content in the ammonia-rich washing water. It should be noted that those skilled in the art can determine AC according to the known NH 、V 水 NH 水 Units, for example, AC NH The unit is kg / h, V 水 The unit is kg / h, NH 水 The unit is mg / kg.

[0019] In an optional embodiment, the calculation formula for the proportion of ammonia content in the activated coke discharged from the activated coke desulfurization and denitrification reaction tower is as follows:

[0020]

[0021] Among them, AC NH ' is the percentage of ammonia content in the activated coke discharged from the activated coke desulfurization and denitrification reaction tower; V AC is the circulation speed of the activated coke. It should be noted that those skilled in the art can determine the AC NH '、VAC Units, for example, AC NH The unit of ' is %, V AC The unit is t / h.

[0022] In an optional embodiment, the total amount of ammonia adsorbed by the active coke in the reaction tower is calculated as follows:

[0023] SET NH =10×(C1+0.5×C2)×AC NH '×AC Relation 3

[0024] Among them, SET NH is the total amount of ammonia adsorbed by the active coke in the reaction tower; the reaction tower includes a constant ammonia content zone and a variable ammonia content zone, C1 is the mass ratio of the active coke in the constant ammonia content zone to the total amount of active coke in the reaction tower; C2 is the mass ratio of the active coke in the variable ammonia content zone to the total amount of active coke in the reaction tower; AC is the total amount of active coke in the reaction tower. It should be noted that those skilled in the art can determine SET based on the known NH , AC units, for example, SET NH The unit of is kg, and the unit of AC is t.

[0025] The total amount of the activated coke in the reaction tower is specifically selected according to different processes in the art and is not limited.

[0026] In an optional embodiment, the C1 and C2 are measured by discharging samples before carrying out the desulfurization and denitrification of the activated coke.

[0027] In an optional implementation manner, C1 and C2 satisfy: C1+C2=1.

[0028] In an optional embodiment, in step (5), the calculation formula for adjusting the flow rate of ammonia water is as follows:

[0029]

[0030] Among them, PRA NH is the total amount of ammonia adsorbed by the active coke in the reaction tower during the ammonia flow adjustment period, DIFF is the adjusted flow rate of ammonia; TIME is the ammonia flow adjustment period; k is the mass concentration of ammonia. It should be noted that those skilled in the art can determine PRA based on the known NH ,DIFF,TIME,k units, for example, PRA NH The unit of is kg, the unit of DIFF is kg / h, the unit of TIME is h, and the unit of k is %.

[0031] In an optional embodiment, in step (5), the calculation formula for the flow rate of the adjusted ammonia water is as follows:

[0032] V=V0+DIFF Relationship 5

[0033] Wherein, V is the flow rate of the ammonia water after adjustment; V0 is the flow rate of the ammonia water before adjustment. It should be noted that those skilled in the art can determine the units of V and V0 according to the known knowledge, for example, the unit of V is kg / h, and the unit of V0 is kg / h.

[0034] The technical solution of the present invention has the following advantages:

[0035] 1. The method for controlling the amount of ammonia sprayed in activated coke desulfurization and denitrification provided by the present invention comprises the following steps: (1) selecting an activated coke desulfurization and denitrification reaction tower to stably discharge NO x (1) the time period of the active coke discharged from the activated coke desulfurization and denitrification reaction tower during the reference period is taken as the reference period, and the ammonia adsorbed by the active coke discharged from the activated coke desulfurization and denitrification reaction tower during the reference period is absorbed by the sulfur-rich flue gas washing water to obtain the ammonia-rich washing water. According to the discharge flow rate of the sulfur-rich flue gas washing water and the ammonia content in the ammonia-rich washing water, the amount of ammonia adsorbed by the active coke discharged from the activated coke desulfurization and denitrification reaction tower during the reference period is calculated; (2) according to the amount of ammonia adsorbed by the active coke discharged from the activated coke desulfurization and denitrification reaction tower during the reference period and the circulation speed of the activated coke, the proportion of ammonia content in the active coke discharged from the activated coke desulfurization and denitrification reaction tower is calculated; (3) according to the amount of ammonia adsorbed by the active coke discharged from the activated coke desulfurization and denitrification reaction tower during the reference period and the circulation speed of the activated coke, the proportion of ammonia content in the active coke discharged from the activated coke desulfurization and denitrification reaction tower during the reference period is calculated; (4) determining the ammonia flow adjustment period during the desulfurization and denitration reaction of activated coke, and calculating the total amount of ammonia adsorbed by the activated coke in the reaction tower according to the amount of ammonia adsorbed by the activated coke discharged from the desulfurization and denitration reaction tower and the ammonia content in the activated coke discharged from the desulfurization and denitration reaction tower; (5) calculating the adjusted flow of ammonia according to the difference between the total amount of ammonia adsorbed by the activated coke in the reaction tower during the reference period and the ammonia flow adjustment period, and then determining the flow of the adjusted ammonia. The present invention determines the flow of the adjusted ammonia by detecting the discharge flow of sulfur-rich flue gas washing water and the ammonia content in the washing water, and the detection equipment has low procurement cost, low maintenance workload, and low accuracy requirements for online detection equipment.

[0036] Specifically, the present invention first selects NO x The emission stable period is taken as the reference period, the activated coke discharged in and out of the reference period is heated, and the ammonia adsorbed by the discharged activated coke is absorbed by the sulfur-rich flue gas washing water. The discharge flow rate of the sulfur-rich flue gas washing water and the ammonia content in the ammonia-rich washing water in this reference period are detected by conventional detection equipment. The detection method is simple and the conditions are easy to achieve. The total amount of ammonia adsorbed by the activated coke in the reaction tower during the reference period is calculated; the total amount of ammonia adsorbed in the desulfurization and denitrification reaction of the activated coke can be detected, and then the adjustment flow rate of ammonia water is obtained, which reduces the influence of adsorbed ammonia on denitrification and avoids the outlet NO x Large fluctuations lead to untimely adjustment of the ammonia flow rate and defects such as lag.

[0037] NO in flue gas x The actual values ​​of load and sulfur-rich flue gas fluctuate frequently. The present invention calculates according to the average value of the period more reasonably and accurately than calculating at any time, and also reduces the operating cost. The ammonia flow rate determined by this method can maintain the total ammonia content of the activated coke bed layer, and the outlet NO x The concentration fluctuation range is ±5mg / m 3 Can be reduced to ±3mg / m 3 , reducing errors. It can be seen from this that the method for controlling the amount of ammonia sprayed in desulfurization and denitrification of activated coke provided by the present invention has the following advantages: x The concentration fluctuates slightly and no ammonia waste is caused. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 The changing pattern of active coke ammonia content in the bed is determined through actual measurement during the discharge process. DETAILED DESCRIPTION

[0040] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0041] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0042] In order to solve the problem that the existing activated coke desulfurization and denitrification process does not consider the impact of the total amount of ammonia in the activated coke system on denitrification, resulting in the outlet NO x The concentration fluctuates greatly, resulting in a lag in the adjustment of the ammonia flow rate. The present invention provides the following technical solution.

[0043] The present invention provides a method for controlling the amount of ammonia sprayed during desulfurization and denitrification of activated coke, comprising the following steps:

[0044] (1) As the activated coke desulfurization and denitrification process proceeds, the activated coke desulfurization and denitrification reaction tower is selected to stabilize the emission of NO x The time period is taken as the reference period, and the ammonia adsorbed by the activated coke discharged from the activated coke desulfurization and denitration reaction tower during the reference period is absorbed by the sulfur-rich flue gas washing water to obtain the ammonia-rich washing water, and the ammonia content in the ammonia-rich washing water is obtained through testing; the amount of ammonia adsorbed by the activated coke discharged from the activated coke desulfurization and denitration reaction tower during the reference period is calculated according to the discharge flow rate of the sulfur-rich flue gas washing water and the ammonia content in the ammonia-rich washing water;

[0045] (2) calculating the proportion of ammonia content in the activated coke discharged from the activated coke desulfurization and denitrification reaction tower according to the amount of ammonia adsorbed by the activated coke discharged from the activated coke desulfurization and denitrification reaction tower and the circulation rate of the activated coke during the reference period;

[0046] (3) calculating the total amount of ammonia adsorbed by the activated coke in the desulfurization and denitration reaction tower according to the amount of ammonia adsorbed by the activated coke discharged from the desulfurization and denitration reaction tower during the reference period and the proportion of ammonia content in the activated coke discharged from the desulfurization and denitration reaction tower;

[0047] (4) determining the ammonia flow adjustment period during the activated coke desulfurization and denitrification reaction process, and calculating the total amount of ammonia adsorbed by the activated coke in the reaction tower during the ammonia flow adjustment period according to the method for calculating the total amount of ammonia adsorbed by the activated coke in the reference period in steps (1) to (3); it should be noted that during the activated coke desulfurization and denitrification process, it is necessary to monitor various parameters in the system, and the activated coke desulfurization and denitrification process is a continuous process;

[0048] (5) Calculating the adjusted flow rate of ammonia water based on the difference between the total amount of ammonia adsorbed by the active coke in the reaction tower during the base period and the ammonia water flow adjustment period, and then determining the flow rate of the adjusted ammonia water, that is, the ammonia injection amount in the next ammonia water flow adjustment period after the end of the ammonia water flow adjustment period.

[0049] It should be noted that there is a reference period in a continuous activated coke desulfurization and denitrification process, and the activated coke desulfurization and denitrification process is divided into several ammonia flow adjustment cycles. The ammonia flow adjustment range is determined according to the change of the total amount of ammonia adsorbed by the activated coke in the reaction tower during the ammonia flow adjustment cycle relative to the reference period, and then the ammonia injection amount of the next ammonia flow adjustment cycle is determined, so as to reduce the outlet NO by maintaining the total ammonia in the system constant. x Concentration fluctuation. It should be noted that all ammonia flow rate adjustment periods are based on the reference period; the ammonia flow rate adjustment period is well known in the art and is not specifically limited in the present invention.

[0050] Example 1

[0051] This embodiment provides a method for controlling the amount of ammonia sprayed during desulfurization and denitrification of activated coke, comprising the following steps:

[0052] (1) Selecting activated coke desulfurization and denitrification reaction tower to stabilize NO emissions x The time period is taken as the base period. x The emission meets the standard. The activated coke at the bottom of the sulfur-rich flue gas washing water absorption reaction tower absorbs ammonia to obtain ammonia-rich washing water. The ammonia content NH in the ammonia-rich washing water is obtained through testing. 水 The discharge flow rate of sulfur-rich flue gas washing water V in the base period is 2580 mg / kg. 水 is 1800kg / h. According to equation 1, the amount of ammonia adsorbed by the activated coke discharged from the reaction tower during the reference period is calculated as AC NH It is 4.64kg / h.

[0053] AC NH =V 水 ×NH 水 ×10 -6 Relation 1

[0054] (2) The amount of ammonia adsorbed by the activated coke discharged from the reaction tower during the reference period AC NH The circulation rate of activated coke is 4.64 kg / h. AC is 28t / h. According to equation 2, the ammonia content in the activated coke discharged from the reaction tower is calculated as AC NH ' is 1.66%.

[0055]

[0056] (3) Before the desulfurization and denitrification reaction of activated coke, the change law of the ammonia content of activated coke in the bed layer is determined by actual measurement during the discharge process. Figure 1 The reaction tower includes a constant ammonia content zone and a variable ammonia content zone. Through discharge sampling, it is determined that the mass ratio of the active coke in the constant ammonia content zone to the total amount of active coke in the reaction tower is C1, which is 0.1, and the mass ratio of the active coke in the variable ammonia content zone to the total amount of active coke in the reaction tower is C2, which is 0.9. The total mass AC of the active coke in the reaction tower is 8000t. The total amount of ammonia adsorbed by the active coke in the reaction tower is calculated according to equation 3: NH It is 730kg.

[0057] SET NH =10×(C1+0.5×C2)×AC NH '×AC Relation 3

[0058] (4) Determine that the ammonia flow adjustment cycle for the activated coke desulfurization and denitrification reaction is 1.5 hours, that is, adjust the ammonia flow rate every 1.5 hours, and use the reference period as the reference to detect the various parameters in the activated coke desulfurization and denitrification process in real time. According to step (1), test the amount of ammonia adsorbed by the activated coke discharged from the bottom of the reaction tower within 1.5 hours, and calculate the total amount of ammonia adsorbed by the activated coke in the reaction tower during the ammonia flow adjustment period according to steps (2)-(3). The various parameters are as follows: the discharge flow rate V of the sulfur-rich flue gas scrubbing water 水 The ammonia content in the ammonia-rich washing water is 2100 kg / h. 水 The amount of ammonia adsorbed by the activated coke discharged from the reaction tower is 2550 mg / kg. NH The circulation rate of activated coke is 5.355 kg / h. AC The content of ammonia in the activated coke discharged from the reaction tower is 28t / h, accounting for AC NH ' is 1.9125%, the ratio of active coke in the constant ammonia content region to the total amount of active coke C1 is 0.1, the ratio of active coke in the linear ammonia content region to the total amount of active coke C2 is 0.9, the total amount of active coke in the reaction tower AC is 8000t, the total amount of ammonia adsorbed by active coke in the reaction tower PRA NH It is 841.5kg.

[0059] (5) Based on the difference between the total amount of ammonia adsorbed by the active coke in the reaction tower during the reference period and the total amount of ammonia adsorbed by the active coke in the reaction tower during the ammonia flow adjustment period, the adjusted ammonia flow rate for the next ammonia flow adjustment period is calculated to be -372 kg / h, and the mass concentration of ammonia is 20%.

[0060]

[0061] (6) The adjusted flow rate of ammonia water is -372 kg / h. The flow rate of ammonia water before adjustment is 900 kg / h. The flow rate of ammonia water after adjustment is calculated to be 528 kg / h.

[0062] V=V0+DIFF Relationship 5.

[0063] The calculations in this embodiment are performed according to the units given in this embodiment when using equations 1-5. Those skilled in the art can adjust the coefficients in equations 1-5 according to the unit conversion relationship. x Concentration<±3mg / m 3 .

[0064] Example 2

[0065] This embodiment provides a method for controlling the amount of ammonia sprayed during desulfurization and denitrification of activated coke, comprising the following steps:

[0066] (1) Selecting activated coke desulfurization and denitrification reaction tower to stabilize NO emissions xThe time period is taken as the base period. x The emission meets the standard. The activated coke at the bottom of the sulfur-rich flue gas washing water absorption reaction tower absorbs ammonia to obtain ammonia-rich washing water. The ammonia content NH in the ammonia-rich washing water is obtained through testing. 水 The discharge flow rate of sulfur-rich flue gas washing water V in the base period is 1890 mg / kg. 水 is 1780kg / h. According to equation 1, the amount of ammonia adsorbed by the activated coke discharged from the reaction tower during the reference period is calculated as AC NH 3.3642kg / h;

[0067] (2) The amount of ammonia adsorbed by the activated coke discharged from the reaction tower during the reference period AC NH The circulation rate of activated coke is 3.3642 kg / h. AC is 25t / h. According to equation 2, the ammonia content in the activated coke discharged from the reaction tower is calculated as AC NH ' is 1.346%;

[0068] (3) Before the desulfurization and denitrification reaction of activated coke, the change law of the ammonia content of activated coke in the bed layer is determined by actual measurement during the discharge process. Figure 1 The reaction tower includes a constant ammonia content zone and a variable ammonia content zone. Through discharge sampling, it is determined that the mass ratio of the active coke in the constant ammonia content zone to the total amount of active coke in the reaction tower is C1, which is 0.15, and the mass ratio of the active coke in the variable ammonia content zone to the total amount of active coke in the reaction tower is C2, which is 0.85. The total mass AC of the active coke in the reaction tower is 7000t. According to the relationship 3, the total amount of ammonia adsorbed by the active coke in the reaction tower is calculated as SET. NH 542kg;

[0069] (4) Determine that the ammonia flow adjustment cycle of the activated coke desulfurization and denitrification reaction is 0.5h, that is, adjust the ammonia flow rate every 0.5h, and take the reference period as the reference, and detect various parameters in the activated coke desulfurization and denitrification process in real time. According to step (1), test the amount of ammonia adsorbed by the activated coke discharged from the bottom of the reaction tower within 0.5h, and calculate the total amount of ammonia adsorbed by the activated coke in the reaction tower during the ammonia flow adjustment period according to steps (2)-(3). The parameters are as follows: the discharge flow rate V of the sulfur-rich flue gas scrubbing water 水 The ammonia content in the ammonia-rich washing water is 2150 kg / h. 水 The amount of ammonia adsorbed by the activated coke discharged from the reaction tower is 1730 mg / kg. NH The circulation rate of activated coke is 3.72 kg / h. AC The content of ammonia in the activated coke discharged from the reaction tower is 28t / h, accounting for AC NH' is 1.33%, the ratio of active coke in the constant ammonia content region to the total amount of active coke C1 is 0.15, the ratio of active coke in the linear ammonia content region to the total amount of active coke C2 is 0.85, the total amount of active coke in the reaction tower AC is 7000t, the total amount of ammonia adsorbed by active coke in the reaction tower PRA NH It is 535kg.

[0070] (5) Based on the difference between the total amount of ammonia adsorbed by the active coke in the reaction tower during the reference period and the total amount of ammonia adsorbed by the active coke in the reaction tower during the ammonia flow adjustment period, the adjusted ammonia flow rate in the next ammonia flow adjustment period is calculated according to equation 4 to be 70 kg / h, and the mass concentration of ammonia is 20%.

[0071] (6) The adjusted flow rate of ammonia water is 70 kg / h. The flow rate of ammonia water before adjustment is 600 kg / h. According to equation 5, the flow rate of ammonia water after adjustment is 670 kg / h.

[0072] The NO emitted in this example x Outlet concentration < ±3mg / m 3 .

[0073] Example 3

[0074] This embodiment provides a method for controlling the amount of ammonia sprayed during desulfurization and denitrification of activated coke, comprising the following steps:

[0075] (1) Selecting activated coke desulfurization and denitrification reaction tower to stabilize NO emissions x The time period is taken as the base period. x The emission meets the standard. The activated coke at the bottom of the sulfur-rich flue gas washing water absorption reaction tower absorbs ammonia to obtain ammonia-rich washing water. The ammonia content NH in the ammonia-rich washing water is obtained through testing. 水 The discharge flow rate of sulfur-rich flue gas washing water V in the base period is 1915 mg / kg. 水 is 1810 kg / h. According to equation 1, the amount of ammonia adsorbed by the activated coke discharged from the reaction tower during the reference period is calculated as AC NH 3.466kg / h;

[0076] (2) The amount of ammonia adsorbed by the activated coke discharged from the reaction tower during the reference period AC NH The circulation rate of activated coke is 3.466 kg / h. AC is 25t / h. According to equation 2, the mass proportion of ammonia in the activated coke discharged from the reaction tower is calculated as AC NH ' is 1.386%;

[0077] (3) Before the desulfurization and denitrification reaction of activated coke, the change law of the ammonia content of activated coke in the bed layer is determined by actual measurement during the discharge process. Figure 1The reaction tower includes a constant ammonia content zone and a variable ammonia content zone. Through discharge sampling, it is determined that the mass ratio of the active coke in the constant ammonia content zone to the total amount of active coke in the reaction tower is C1, which is 0.5, and the mass ratio of the active coke in the variable ammonia content zone to the total amount of active coke in the reaction tower is C2, which is 0.5. The total mass AC of the active coke in the reaction tower is 8000t. According to the relationship 3, the total amount of ammonia adsorbed by the active coke in the reaction tower is calculated as SET. NH 831.6kg;

[0078] (4) Determine that the ammonia flow adjustment cycle for the activated coke desulfurization and denitrification reaction is 2 hours, that is, adjust the ammonia flow rate every 2 hours, and use the reference period as the reference to detect various parameters in the activated coke desulfurization and denitrification process in real time. According to step (1), test the amount of ammonia adsorbed by the activated coke discharged from the bottom of the reaction tower within 2 hours, and calculate the total amount of ammonia adsorbed by the activated coke in the reaction tower during the ammonia flow adjustment period according to steps (2)-(3). The parameters are as follows: the discharge flow rate V of the sulfur-rich flue gas scrubbing water 水 The ammonia content in the ammonia-rich washing water is 2140 kg / h. 水 The amount of ammonia adsorbed by the activated coke discharged from the reaction tower is 1710 mg / kg. NH The circulation rate of activated coke is 3.66 kg / h. AC The content of ammonia in the activated coke discharged from the reaction tower is 28t / h, accounting for AC NH ' is 1.307%, the ratio of active coke in the constant ammonia content region to the total amount of active coke C1 is 0.5, the ratio of active coke in the linear ammonia content region to the total amount of active coke C2 is 0.5, the total amount of active coke in the reaction tower AC is 8000t, the total amount of ammonia adsorbed by active coke in the reaction tower PRA NH It is 784.2kg.

[0079] (5) Based on the difference between the total amount of ammonia adsorbed by the active coke in the reaction tower during the reference period and the total amount of ammonia adsorbed by the active coke in the reaction tower during the ammonia flow adjustment period, the adjusted ammonia flow rate in the next ammonia flow adjustment period is calculated according to equation 4 to be 119 kg / h, and the mass concentration of ammonia is 20%.

[0080] (6) The adjusted flow rate of ammonia water is 119 kg / h, the original flow rate of ammonia water is 350 kg / h, and the adjusted flow rate of ammonia water is 469 kg / h according to equation 5.

[0081] The NO emitted in this example x Outlet concentration < ±3mg / m 3 .

[0082] Example 4

[0083] This embodiment provides a method for controlling the amount of ammonia sprayed during desulfurization and denitrification of activated coke, comprising the following steps:

[0084] (1) Selecting activated coke desulfurization and denitrification reaction tower to stabilize NO emissions x The time period is taken as the base period. x The emission meets the standard. The activated coke at the bottom of the sulfur-rich flue gas washing water absorption reaction tower absorbs ammonia to obtain ammonia-rich washing water. The ammonia content NH in the ammonia-rich washing water is obtained through testing. 水 The discharge flow rate of sulfur-rich flue gas washing water V in the base period is 3200 mg / kg. 水 is 2510 kg / h. According to equation 1, the amount of ammonia adsorbed by the activated coke discharged from the reaction tower during the reference period is calculated as AC NH 8.03kg / h;

[0085] (2) The amount of ammonia adsorbed by the activated coke discharged from the reaction tower during the reference period is AC NH 8.03kg / h, the circulation rate of activated coke V AC is 30t / h. According to equation 2, the mass proportion of ammonia in the activated coke discharged from the reaction tower is calculated as AC NH ' is 2.677%;

[0086] (3) Before the desulfurization and denitrification reaction of activated coke, the change law of the ammonia content of activated coke in the bed layer is determined by actual measurement during the discharge process. Figure 1 The reaction tower includes a constant ammonia content zone and a variable ammonia content zone. Through discharge sampling, it is determined that the mass ratio of the active coke in the constant ammonia content zone to the total amount of active coke in the reaction tower is C1, which is 0.1, and the mass ratio of the active coke in the variable ammonia content zone to the total amount of active coke in the reaction tower is C2, which is 0.9. The total mass AC of the active coke in the reaction tower is 13000t. The total amount of ammonia adsorbed by the active coke in the reaction tower is calculated according to the relationship 3: NH It is 1914kg.

[0087] (4) Determine that the ammonia flow adjustment cycle for the activated coke desulfurization and denitrification reaction is 2 hours, that is, adjust the ammonia flow rate every 2 hours, and use the reference period as the reference to detect various parameters in the activated coke desulfurization and denitrification process in real time. According to step (1), test the amount of ammonia adsorbed by the activated coke discharged from the bottom of the reaction tower within 2 hours, and calculate the total amount of ammonia adsorbed by the activated coke in the reaction tower during the ammonia flow adjustment period according to steps (2)-(3). The parameters are as follows: the discharge flow rate V of the sulfur-rich flue gas scrubbing water 水 The ammonia content in the ammonia-rich washing water is 3850 kg / h. 水 The amount of ammonia adsorbed by the activated coke discharged from the reaction tower is 1930 mg / kg. NH The circulation rate of activated coke is 7.43 kg / h. AC The content of ammonia in the activated coke discharged from the reaction tower is 28t / h, accounting for AC NH' is 2.6536%, the ratio of active coke in the constant ammonia content region to the total amount of active coke C1 is 0.1, the ratio of active coke in the linear ammonia content region to the total amount of active coke C2 is 0.9, the total amount of active coke in the reaction tower AC is 13000t, the total amount of ammonia adsorbed by active coke in the reaction tower PRA NH It is 1897kg.

[0088] (5) Based on the difference between the total amount of ammonia adsorbed by the active coke in the reaction tower during the reference period and the total amount of ammonia adsorbed by the active coke in the reaction tower during the ammonia flow adjustment period, the adjusted ammonia flow rate in the next ammonia flow adjustment period is calculated according to equation 4 to be 42 kg / h, and the mass concentration of ammonia is 20%.

[0089] (6) The adjusted flow rate of ammonia water is 42 kg / h. The flow rate of ammonia water before adjustment is 850 kg / h. According to equation 5, the flow rate of ammonia water after adjustment is 892 kg / h.

[0090] The NO emitted in this example x Outlet concentration < ±3mg / m 3 .

[0091] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention.

Claims

1. A method for controlling the amount of ammonia sprayed for desulfurization and denitrification of activated coke, characterized in that: The steps include: (1) Selecting activated coke desulfurization and denitrification reaction tower to stabilize NO emissions x The time period is taken as the reference period, and the ammonia adsorbed by the activated coke discharged from the activated coke desulfurization and denitration reaction tower during the reference period is absorbed by the sulfur-rich flue gas washing water to obtain the ammonia-rich washing water, and the amount of ammonia adsorbed by the activated coke discharged from the activated coke desulfurization and denitration reaction tower during the reference period is calculated according to the discharge flow rate of the sulfur-rich flue gas washing water and the ammonia content in the ammonia-rich washing water; (2) calculating the proportion of ammonia content in the activated coke discharged from the activated coke desulfurization and denitrification reaction tower according to the amount of ammonia adsorbed by the activated coke discharged from the activated coke desulfurization and denitrification reaction tower and the circulation rate of the activated coke during the reference period; (3) calculating the total amount of ammonia adsorbed by the activated coke in the desulfurization and denitration reaction tower according to the amount of ammonia adsorbed by the activated coke discharged from the desulfurization and denitration reaction tower during the reference period and the proportion of ammonia content in the activated coke discharged from the desulfurization and denitration reaction tower; (4) determining the ammonia flow adjustment period during the desulfurization and denitrification reaction of the activated coke, and calculating the total amount of ammonia adsorbed by the activated coke in the reaction tower during the ammonia flow adjustment period according to the method for calculating the total amount of ammonia adsorbed by the activated coke in the reaction tower during the base period in steps (1) to (3); (5) Calculating the adjusted flow rate of ammonia water according to the difference between the total amount of ammonia adsorbed by the active coke in the reaction tower during the base period and the ammonia water flow rate adjustment period, and then determining the flow rate of the ammonia water after adjustment.

2. The control method according to claim 1, characterized in that: The calculation formula for the amount of ammonia adsorbed by the activated coke discharged from the activated coke desulfurization and denitrification reaction tower during the reference period is as follows: AC NH =V 水 ×NH 水 ×10 -6 Relation 1 Among them, AC NH V is the amount of ammonia adsorbed by the activated coke discharged from the activated coke desulfurization and denitrification reaction tower during the reference period; 水 is the discharge flow of sulfur-rich flue gas scrubbing water; NH 水 is the ammonia content in the ammonia-rich wash water.

3. The control method according to claim 1, characterized in that: In the step (2), the calculation formula for the proportion of ammonia content in the activated coke discharged from the activated coke desulfurization and denitrification reaction tower is as follows: Among them, AC NH ' is the percentage of ammonia content in the activated coke discharged from the activated coke desulfurization and denitrification reaction tower; V AC is the circulation speed of the active coke.

4. The control method according to claim 1, characterized in that: In the step (3), the total amount of ammonia adsorbed by the active coke in the reaction tower is calculated as follows: SET NH =10×(C1+0.5×C2)×AC NH ′×AC Relation 3 Among them, SET NH is the total amount of ammonia adsorbed by the active coke in the reaction tower; the reaction tower comprises a constant ammonia content zone and a variable ammonia content zone, C1 is the mass proportion of the active coke in the constant ammonia content zone to the total amount of active coke in the reaction tower; C2 is the mass proportion of the active coke in the variable ammonia content zone to the total amount of active coke in the reaction tower; AC is the total amount of active coke in the reaction tower.

5. The control method according to claim 4, characterized in that: Before carrying out the desulfurization and denitrification of the activated coke, the C1 and C2 are measured by discharging samples.

6. The control method according to claim 4 or 5, characterized in that: The C1 and C2 satisfy: C1+C2=1.

7. The control method according to claim 1, characterized in that: In the step (5), the calculation formula for adjusting the flow rate of ammonia water is as follows: Among them, PRA NH is the total amount of ammonia adsorbed by the active coke in the reaction tower during the ammonia flow adjustment period; DIFF is the adjusted flow rate of ammonia; TIME is the ammonia flow adjustment period; and k is the mass concentration of ammonia.

8. The control method according to claim 7, characterized in that: In the step (5), the calculation formula of the flow rate of the adjusted ammonia water is as follows: V=V0+DIFF Relationship 5 Wherein, V is the flow rate of ammonia water after adjustment; V0 is the flow rate of ammonia water before adjustment.

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