A parameter control method and control system for enhancing SNCR systems

Abstract

This invention discloses a parameter control method and control system for an enhanced SNCR system, belonging to the field of flue gas denitrification technology in the cement industry. The enhanced SNCR system includes M1 water pumps, M2 spray guns connected in parallel, and a controller for controlling the working status of the water pumps and spray guns; the parameters of the M1 water pumps are identical; the parameter control method includes: S1, acquiring basic parameters; the basic parameters include the pressure H at the lowest flow rate within ±12.5% ​​of the mid-section flow rate variation of the spray gun performance curve. low The pressure H at the highest flow rate within ±12.5% ​​of the mid-section flow rate variation of the spray gun performance curve. high The lower limit of the flow rate variation range of the denitrification agent in the SNCR system, Q low The upper limit of the flow rate variation range of the denitrification agent in the SNCR system, Q high 1. Pump friction s; S2. Basic parameter analysis; S3. Strengthening the SNCR system by controlling the number of pumps N and the number of spray guns n. This ensures the stability of the spray gun operation.

Description

Technical Field

[0001] This invention belongs to the field of flue gas denitrification technology in the cement industry, specifically relating to a parameter control method and control system for an enhanced SNCR system. Background Technology

[0002] Nitrogen oxides (NOx) are harmful pollutants that can easily cause acid rain and other damage. Currently, the cement industry widely uses Selective Non-Catalytic Reduction (SNCR) technology to reduce NOx emissions. SNCR technology has been widely adopted due to its advantages such as simple retrofitting and low investment. However, a serious problem with SNCR systems in the cement industry is its inability to solve the issue of poor atomization.

[0003] The direct cause of poor atomization is that the pressure and flow ratio of the water and air circuits cannot closely approximate the working state of the spray gun's atomization curve. There are three main underlying reasons: First, adjusting the flow rate via a frequency converter causes the pump's operating head to change with the flow rate, resulting in a significant deviation in the spray gun's water circuit pressure. Second, the system resistance changes with the opening of the regulating valve, further deviating the water circuit pressure. Third, the water and air circuit pressures are mismatched, leading to a deviation in the flow ratio between the water and air circuits.

[0004] Researchers are currently working to solve the atomization problem of spray guns. For example, CN111773909A focuses on improving the performance of spray guns. It first groups the spray guns and independently controls the flow rate of each group, ensuring that the resistance loss, working pressure, flow distribution, and atomization state are the same within each group. This results in a consistent atomization state of the sprayed reducing agent, thus improving the SNCR effect. However, CN111773909A still relies on adjusting the pump speed and valve opening to regulate the ammonia flow rate. Therefore, while it can only guarantee that the atomization effect of each spray gun is the same, it cannot guarantee a superior atomization effect.

[0005] CN213032224U divides the SNCR system into multiple completely independent subsystems, each controlling its own spray gun, thereby enhancing the adjustability of the SNCR control system. However, it still relies on adjusting the pump speed and valve opening to regulate the ammonia flow rate, which cannot solve the problem of poor atomization effect.

[0006] Currently, intelligent SNCR systems focus on calculating ammonia usage. For example, CN114067933A uses intelligent calculation to provide information on changes in ammonia usage. However, it still relies on adjusting the pump speed and valve opening, thus failing to solve the problem of poor atomization.

[0007] Therefore, the technical problem that this invention aims to solve is as follows:

[0008] 1) Currently, SNCR systems generally use dual-fluid atomizing spray guns, one for the denitrification agent and the other for compressed air. The flow rate adjustment of the denitrification agent (ammonia, urea, etc.) typically involves methods such as frequency conversion of centrifugal water pumps or changing valve openings. This results in the centrifugal water pump outlet flow rate meeting requirements, but not the pressure stability requirements. The pump's operating head varies significantly, leading to drastic changes in the pump's QH (flow rate-head) curve and large pressure fluctuations in the denitrification agent, failing to stabilize within the ideal performance curve of the spray gun. Using a special type of water pump would significantly increase pump costs. Therefore, there is an urgent need for a method that utilizes ordinary water pumps to solve the problem of significant head variations when adjusting the flow rate using ordinary water pumps.

[0009] 2) Currently, the spray guns account for most of the resistance in the SNCR system, and the number of spray guns is generally fixed. Therefore, the friction of the SNCR system is approximately constant. Since the system resistance is quadratic with the flow rate, the system resistance will change significantly when the flow rate is adjusted. This results in a large fluctuation range in the pressure of the denitrifying agent, which cannot be stabilized in the middle part of the ideal performance curve of the spray gun.

[0010] 3) The atomization effect of a dual-fluid atomizing spray gun requires that the pressures of the compressed air and the denitrifying agent be close, and both be close to the pressure requirements on the ideal performance curve of the spray gun. Generally, the compressed air pressure provided by air compressors in industrial enterprises is stable and can meet the pressure requirements. However, when the flow rate of the denitrifying agent changes, the pressure of the denitrifying agent will deviate significantly from the ideal performance curve of the spray gun.

[0011] 4) The atomization effect of the dual-fluid atomizing spray gun requires the flow rates of compressed air and denitrifying agent to maintain a specific ratio according to the ideal performance curve of the spray gun. However, when the pressure of the denitrifying agent deviates from the pressure of the compressed air, the flow rates of the two change significantly, resulting in a serious deviation in the flow ratio between compressed air and denitrifying agent.

[0012] 5) The atomization effect of the dual-fluid atomizing spray gun is poor because the pressure and flow rate relationship between compressed air and denitrifying agent is unbalanced, resulting in uneven particle size and particle size distribution of the sprayed denitrifying agent atomized particles. This leads to poor denitrification effect, large denitrifying agent consumption, high operating costs, and easy exceedance of nitrogen oxide emissions.

[0013] 6) Current SNCR intelligent systems typically use a control loop of nitrogen oxide emission concentration - denitrification agent dosage - water pump frequency conversion speed regulation. This loop assumes that nitrogen oxide emission concentration is related to the denitrification agent dosage but not to atomization effect. When nitrogen oxide emission concentration is high, the water pump speed is increased to increase the denitrification agent dosage; when nitrogen oxide emission concentration is low, the speed is decreased to reduce the denitrification agent dosage. However, the intelligent system struggles to respond to deteriorating atomization effects. When poor denitrification results in ineffective denitrification, the intelligent system increases the water pump frequency and denitrification agent dosage, further worsening the atomization effect and increasing nitrogen oxide emission concentration. This leads the intelligent control system to continue increasing the water pump frequency and ammonia dosage, creating a vicious cycle within the control loop. Ultimately, nitrogen oxide emission concentrations remain above the limit for an extended period, forcing the company to halt production.

[0014] The best atomization effect can be guaranteed when the spray gun is used in the middle of its ideal performance curve. However, due to the limitations of compressed air and denitrifying agent adjustment, it is difficult to ensure that the flow rates of compressed air and denitrifying agent are both in the middle of the ideal performance curve. Summary of the Invention

[0015] To address the technical problems existing in the prior art, this invention provides a parameter control method and control system for enhancing the SNCR system, thereby achieving stability in the operation of the spray gun within the SNCR system.

[0016] The first objective of this invention is to provide a parameter control method for an enhanced SNCR system, wherein the enhanced SNCR system includes M1 water pumps, M2 spray guns, and a controller for controlling the operating states of the water pumps and spray guns connected in parallel; the parameters of the M1 water pumps are identical; the parameter control method includes:

[0017] S1. Obtain basic parameters; the basic parameters include the pressure H at the lowest flow rate within ±12.5% ​​of the mid-section flow rate variation of the spray gun performance curve. low The pressure H at the highest flow rate within ±12.5% ​​of the mid-section flow rate variation of the spray gun performance curve. high The lower limit of the flow rate variation range of the denitrification agent in the SNCR system, Q low The upper limit of the flow rate variation range of the denitrification agent in the SNCR system, Q high Pump friction s;

[0018] S2. Basic parameter analysis;

[0019] The number of water pumps N that are turned on can be obtained using the following formula:

[0020]

[0021] The number of spray guns, n, that are activated is obtained using the following formula:

[0022] n = denitrification agent dosage Q / the midpoint flow rate q of the spray gun performance curve, rounded up to the nearest integer;

[0023] S3. The SNCR system is enhanced by controlling the number of water pumps N and the number of spray guns n in S2.

[0024] Preferably, the variation in pump operating head within the flow range of the enhanced SNCR system is less than 4m.

[0025] Preferably, the head pressure is 0.04 MPa.

[0026] Preferably, n is not less than 4.

[0027] The second objective of this aspect is to provide a parameter control system for an enhanced SNCR system, the enhanced SNCR system comprising M1 water pumps, M2 spray guns connected in parallel, and a controller for controlling the operating states of the water pumps and spray guns; the parameters of the M1 water pumps are identical; the parameter control system includes:

[0028] Basic parameter acquisition module; the basic parameters include the pressure H at the lowest flow rate within ±12.5% ​​of the mid-section flow rate variation of the spray gun performance curve. low The pressure H at the highest flow rate within ±12.5% ​​of the mid-section flow rate variation of the spray gun performance curve. high The lower limit of the flow rate variation range of the denitrification agent in the SNCR system, Q low The upper limit of the flow rate variation range of the denitrification agent in the SNCR system, Q high Pump friction s;

[0029] Basic parameter analysis module;

[0030] The number of water pumps N that are turned on can be obtained using the following formula:

[0031]

[0032] The number of spray guns, n, that are activated is obtained using the following formula:

[0033] n = denitrification agent dosage Q / the midpoint flow rate q of the spray gun performance curve, rounded up to the nearest integer;

[0034] Control module: The SNCR system is enhanced by controlling the number of water pumps N and the number of spray guns n in the basic parameter analysis module.

[0035] Preferably, the variation in pump operating head within the flow range of the enhanced SNCR system is less than 4m.

[0036] Preferably, the head pressure is 0.04 MPa.

[0037] Preferably, n is not less than 4.

[0038] A third objective of this invention is to provide an information data processing terminal for implementing the parameter control method of the enhanced SNCR system described above.

[0039] A fourth objective of this invention is to provide a computer-readable storage medium including instructions that, when executed on a computer, cause the computer to perform a parameter control method for implementing the enhanced SNCR system described above.

[0040] The advantages and positive effects of this invention are:

[0041] 1) This application can use a common standard water pump combination to achieve a stable pump outlet head (pressure) when the flow rate changes, a smooth QH (flow rate-head) curve of the water pump, and a small pressure fluctuation range of the denitrification agent, which can be stabilized in the middle part of the ideal performance curve of the spray gun.

[0042] 2) After adopting the technical solution of this application, the number of spray guns in the SNCR system varies according to the flow rate of the denitrifying agent, thereby ensuring that the friction of the SNCR system varies according to the flow rate of the denitrifying agent. The pipeline resistance of the SNCR system remains stable when the flow rate changes, reducing the pressure fluctuation range of the denitrifying agent and stabilizing it in the middle part of the ideal performance curve of the spray gun.

[0043] 3) After adopting the technical solution of this application, the pressures of compressed air and denitrification agent are close and both are close to the pressure requirements on the ideal performance curve of the spray gun, and will not deviate from the ideal performance curve of the spray gun.

[0044] 4) After adopting the technical solution of this application, since the pressure of both compressed air and denitrification agent is close to the pressure requirement on the ideal performance curve of the spray gun, the flow ratio between the two also remains stable.

[0045] 5) After adopting the technical solution of this application, the pressure and flow relationship between compressed air and denitrification agent remain stable, resulting in uniform particle size distribution of the sprayed denitrification agent atomized particles, good atomization effect, good denitrification effect, small amount of denitrification agent, and stable and compliant nitrogen oxide emissions.

[0046] 6) After adopting the technical solution of this application, the control logic of the intelligent control system no longer adjusts the flow rate by adjusting the frequency of the water pump, but adjusts the flow rate by adjusting the number of spray guns. This can effectively respond to the deterioration of the atomization effect and avoid the vicious cycle of increasing ammonia water flow and increasing nitrogen oxide emissions caused by poor atomization effect in the control loop, thereby reducing the environmental risks of enterprises.

[0047] 7) After adopting the technical solution of this application, the flow rate of compressed air and the flow rate of denitrification agent are both in the middle part of the ideal performance curve, thereby ensuring the best atomization effect.

[0048] 8) After adopting the technical solution of this application, the amount of denitrification agent used in the SNCR system is reduced, and the operating cost is lower. Attached Figure Description

[0049] Figure 1 It is a waterway flow diagram in traditional technology;

[0050] Figure 2 This is a water flow diagram in an embodiment of the present invention;

[0051] Figure 3 HQ curves for multiple water pumps in operation;

[0052] In the diagram: 1. Denitrification agent container, 2. Water pump, 3. Regulating valve, 4. Flow meter, 5. Pressure measuring device, 6. Spray gun. Detailed Implementation

[0053] To further understand the invention's content, features, and effects, the following embodiments are provided, and detailed descriptions are given below in conjunction with the accompanying drawings:

[0054] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the technical solutions of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] Please see Figures 1 to 3 .

[0056] The SNCR system includes a denitrification agent container 1, a water pump 2, a regulating valve 3, a flow meter 4, a pressure measuring device 5, and a spray gun 6; multiple water pumps 2 are connected in parallel, and multiple spray gun paths are provided. Each spray gun path includes a regulating valve 3, a flow meter 4, a pressure measuring device 5, and a spray gun 6 in sequence.

[0057] A parameter control method for an enhanced SNCR system, the enhanced SNCR system comprising M1 water pumps, M2 spray guns connected in parallel, and a controller for controlling the operating states of the water pumps and spray guns; the parameters of the M1 water pumps are identical; the parameter control method includes:

[0058] S1. Obtain basic parameters; the basic parameters include the pressure H at the lowest flow rate within ±12.5% ​​of the mid-section flow rate variation of the spray gun performance curve. low The pressure H at the highest flow rate within ±12.5% ​​of the mid-section flow rate variation of the spray gun performance curve. high The lower limit of the flow rate variation range of the denitrification agent in the SNCR system, Q low The upper limit of the flow rate variation range of the denitrification agent in the SNCR system, Qhigh Pump friction s;

[0059] S2. Basic parameter analysis;

[0060] The number of water pumps N that are turned on can be obtained using the following formula:

[0061]

[0062] The number of spray guns, n, that are activated is obtained using the following formula:

[0063] n = denitrification agent dosage Q / the midpoint flow rate q of the spray gun performance curve, rounded up to the nearest integer;

[0064] S3. The SNCR system is enhanced by controlling the number of water pumps N and the number of spray guns n in S2.

[0065] In this preferred embodiment:

[0066] 1) The SNCR system uses pumps of the same model operating in parallel;

[0067] 2) The variation in pump head within the operating range of the SNCR system flow rate is less than 4m;

[0068] 3) The number N of pumps operating in the SNCR system is calculated and rounded up.

[0069]

[0070] H low The pressure at the lowest flow rate within ±12.5% ​​of the mid-range flow rate variation of the spray gun performance curve.

[0071] H high The pressure at the highest flow rate within ±12.5% ​​of the mid-range flow rate variation of the spray gun performance curve.

[0072] H low -H high =0.04MPa, which is the pressure at a water head of 4m.

[0073] Q low The lower limit of the flow rate variation range of the denitrification agent in the SNCR system.

[0074] Q high The upper limit of the flow rate variation range of the denitrification agent in the SNCR system.

[0075] The pump friction is determined by the manufacturer or during the production process.

[0076] The number of operating spray guns is determined based on the amount of denitrifying agent required by the system. The calculation method is: number of operating spray guns n = system denitrifying agent amount Q / intermediate flow rate q of the spray gun performance curve, rounded up to the nearest integer.

[0077] The number of spray guns, n, that are in operation should be greater than or equal to 4.

[0078] In the above preferred embodiment, according to the information provided by the spray gun manufacturer, the atomization range is generally within ±12.5% ​​of the flow rate variation in the middle section of the spray gun performance curve. Under this condition, the pressure fluctuation range of the denitrification agent should not exceed 0.4 Bar (approximately 0.04 MPa, equivalent to a water pump head of 4 m).

[0079] The pumps suitable for cement SNCR systems are centrifugal pumps. A typical pump is the CDL1-21 pump from Southern Pump Industry. According to the pump manual, the rated flow rate of a single pump is 1 m3 / h, the rated head is 117 m (1 m head is approximately equal to 0.01 MPa pressure), and the power is 1.1 kW. The head is 124m when the flow rate is 0.4m³ / h; 122m when the flow rate is 0.6m³ / h; 120m when the flow rate is 0.8m³ / h; 110m when the flow rate is 1.2m³ / h; 106m when the flow rate is 1.4m³ / h; 98m when the flow rate is 1.6m³ / h; 87m when the flow rate is 1.8m³ / h; and 75m when the flow rate is 2.0m³ / h. According to the performance curve, the head is approximately 128m when the flow rate is close to 0m³ / h. See Table 1 below.

[0080] Table 1 shows the basic parameters of the water pump.

[0081] Flow rate (m³ / h) Head (m) Pressure (MPa) 0 127 1.27 0.4 124 1.24 0.6 122 1.22 0.8 120 1.20 1 117 1.17 1.2 110 1.10 1.4 106 1.06 1.6 98 0.98 1.8 87 0.87 2.0 75 0.75

[0082] When a single water pump is running, changes in flow rate cause significant pressure variations, easily exceeding 0.04 MPa. Furthermore, the smaller the flow rate, the smaller the pressure change caused by flow rate fluctuations.

[0083] However, when multiple water pumps operate in parallel, the pump head decreases significantly with changes in flow rate. This is based on common knowledge found in Figure 4-8 on page 123 of the textbook for the Water Supply and Drainage Professional Qualification Examination (2020 edition). Figure 3 When multiple pumps are connected in parallel, the sensitivity of the head to changes in flow rate is significantly reduced. Therefore, by increasing the number of pumps operating in parallel, the head variation within the flow rate range can be ensured to be less than 0.04 MPa.

[0084] The principle is as follows: when N identical water pumps are running, the hydraulic characteristic equation is:

[0085] H p (Head) = H b (Head of a single pump when the flow rate is 0) - s(pump friction) * Q(flow rate)2 / N (Number of parallel units) 2 ;

[0086] When the flow rate of the denitrifying agent in the system is at the lower limit of its variation range, H has low =H b -s*Q low 2 / N;

[0087] When the flow rate of the denitrifying agent in the system reaches the upper limit of its variation range, H has... high =H b -s*Q high 2 / N;

[0088] After simplification, we get:

[0089]

[0090] 4) Determine the number of operating spray guns based on the required amount of denitrifying agent in the system. The calculation method is: number of operating spray guns n = system denitrifying agent amount Q / intermediate flow rate q of the spray gun performance curve, rounded up to the nearest integer.

[0091] According to hydraulics, the system resistance H = frictional resistance S * flow rate Q 2 ;

[0092] Since the spray guns are connected in parallel, and since the resistance of the spray gun accounts for most of the resistance of each spray gun pipeline, the frictional resistance S0 of a single spray gun is used to represent the frictional resistance of a single spray gun pipeline.

[0093] ① When using n1 spray guns,

[0094] According to hydraulics, when the flow rate is Q1:

[0095]

[0096] Then we have S1 = S0 / n1 2 H1 = S1 * Q1 2 ;

[0097] The flow rate of each spray gun is q1 = Q1 / n1;

[0098] According to hydraulics, when the flow rate is Q2:

[0099] S1 = S0 / n1 2 H2 = S1 * Q2 2 ;

[0100] The flow rate of each spray gun is q2 = Q2 / n1;

[0101] Therefore: H2 / H1=S1*Q2 2 / (S1*Q12 )=(Q2 / Q1) 2 ;

[0102] q2 / q1=Q2 / n1 / (Q1 / n1)=Q2 / Q1;

[0103] Therefore, as the flow rate changes, the flow rate of a single spray gun and the resistance of the system both change significantly. When the flow rate increases by 1 time, the flow rate of a single spray gun increases to 2 times, and the resistance of a single spray gun can increase to 4 times.

[0104] ② When the number of spray guns n = system denitrification agent dosage Q / intermediate flow rate q of the spray gun performance curve is used, the number of spray guns at the original flow rate Q1 remains n1, and the number of spray guns at the flow rate Q3 becomes n3:

[0105]

[0106]

[0107] Then we have S1 = S0 / n1 2 H1 = S1 * Q1 2 ;

[0108] S3 = S0 / n3 2 H3 = S3 * Q3 2 ;

[0109] Also, n3 = Q3 / q, n1 = Q1 / q;

[0110] H1 = S1 * Q1 2 =S0 / n1 2* (n1*q) 2 =S0*q 2 ;

[0111] H3 = S3 * Q3 2 =S0 / n3 2* (n3*q) 2 =S0*q 2 =H1;

[0112] Therefore, regardless of changes in the total flow rate, the flow rate of a single spray gun and the resistance of the system remain constant.

[0113] 5) The number of spray guns, n, that are in operation should be greater than or equal to 4.

[0114] Since n can only take integer values, the flow rate of a single spray gun may still fluctuate significantly when the value of n is small.

[0115] When n=2, the flow rate Q can be as close as 2.5 times the intermediate flow rate q of the spray gun performance curve, and the actual flow rate of a single spray gun is as close as 1.25 times the intermediate flow rate q of the spray gun performance curve.

[0116] When n=3, the flow rate Q can be as close as 3.5 times the intermediate flow rate q of the spray gun performance curve, and the actual flow rate of a single spray gun is as close as 1.17 times the intermediate flow rate q of the spray gun performance curve.

[0117] When n=4, the flow rate Q can be as close as 4.5 times the intermediate flow rate q of the spray gun performance curve, and the actual flow rate of a single spray gun is as close as 1.125 times the intermediate flow rate q of the spray gun performance curve.

[0118] Therefore, in order to meet the requirement of ±12.5% ​​of the flow rate variation in the middle section of the spray gun performance curve (i.e., 0.875-1.125 times the middle flow rate q of the spray gun performance curve), n should be greater than or equal to 4.

[0119] A parameter control system for an enhanced SNCR system, the enhanced SNCR system comprising M1 water pumps, M2 spray guns connected in parallel, and a controller for controlling the operating states of the water pumps and spray guns; the parameters of the M1 water pumps are identical; the parameter control system includes:

[0120] Basic parameter acquisition module; the basic parameters include the pressure H at the lowest flow rate within ±12.5% ​​of the mid-section flow rate variation of the spray gun performance curve. low The pressure H at the highest flow rate within ±12.5% ​​of the mid-section flow rate variation of the spray gun performance curve. high The lower limit of the flow rate variation range of the denitrification agent in the SNCR system, Q low The upper limit of the flow rate variation range of the denitrification agent in the SNCR system, Q high Pump friction s;

[0121] Basic parameter analysis module;

[0122] The number of water pumps N that are turned on can be obtained using the following formula:

[0123]

[0124] The number of spray guns, n, that are activated is obtained using the following formula:

[0125] n = denitrification agent dosage Q / the midpoint flow rate q of the spray gun performance curve, rounded up to the nearest integer;

[0126] Control module: The SNCR system is enhanced by controlling the number of water pumps N and the number of spray guns n in the basic parameter analysis module.

[0127] In this preferred embodiment:

[0128] 3) The SNCR system uses pumps of the same model operating in parallel;

[0129] 4) The variation in pump operating head within the operating range of the SNCR system is less than 4m;

[0130] 3) The number N of pumps operating in the SNCR system is calculated and rounded up.

[0131]

[0132] H low The pressure at the lowest flow rate within ±12.5% ​​of the mid-range flow rate variation of the spray gun performance curve.

[0133] H high The pressure at the highest flow rate within ±12.5% ​​of the mid-range flow rate variation of the spray gun performance curve.

[0134] H low -H high =0.04MPa, which is the pressure at a water head of 4m.

[0135] Q low The lower limit of the flow rate variation range of the denitrification agent in the SNCR system.

[0136] Q high The upper limit of the flow rate variation range of the denitrification agent in the SNCR system.

[0137] The pump friction is determined by the manufacturer or during the production process.

[0138] The number of operating spray guns is determined based on the amount of denitrifying agent required by the system. The calculation method is: number of operating spray guns n = system denitrifying agent amount Q / intermediate flow rate q of the spray gun performance curve, rounded up to the nearest integer.

[0139] The number of spray guns, n, that are in operation should be greater than or equal to 4.

[0140] Table 2 shows the performance of the CDL1 series water pumps from Nanfang Pump Industry.

[0141]

[0142] For example:

[0143] The SNCR system of a cement plant in Zhejiang Province includes: 4 water pumps, 12 spray guns, each spray gun's ammonia water pipeline has a pressure measuring device and a regulating valve, and the compressed air main pipeline has a pressure measuring device and a regulating valve. The flow rate of the denitrification agent varies from 0.2 to 0.8 m³ / h.

[0144] According to the curve provided by the spray gun manufacturer, within the middle range of approximately ±12.5% ​​of the spray gun performance curve, the pressure fluctuation range of ammonia water is 0.4 Bar (equivalent to 0.04 MPa), and the ammonia water flow rate of a single spray gun is 0.8-1.2 l / min (48-72 l / h). That is, the ideal flow rate range of a single spray gun is 48-72 l / h, and 70 l / h is taken as the basis for calculation.

[0145] The water pump is a CDL1-21 model from Nanfang Pump Industry. According to the pump manual, the rated flow rate of a single pump is 1 m3 / h, the rated head is 117 m (1 m head is approximately equal to 0.01 MPa pressure), and the power is 1.1 kW. The head is 124m when the flow rate is 0.4m³ / h; 122m when the flow rate is 0.6m³ / h; 120m when the flow rate is 0.8m³ / h; 110m when the flow rate is 1.2m³ / h; 106m when the flow rate is 1.4m³ / h; 98m when the flow rate is 1.6m³ / h; 87m when the flow rate is 1.8m³ / h; and 75m when the flow rate is 2.0m³ / h. According to the performance curve, the head is approximately 128m when the flow rate is close to 0m³ / h.

[0146] Therefore, when the ammonia flow rate of the SNCR system is adjusted within the range of 0.2-0.8 m3 / h, using a single water pump for adjustment, the outlet pressure variation range is 1.26-1.20 MPa, with a fluctuation value of 0.06 MPa.

[0147] When four water pumps are connected in parallel for regulation, the flow rate ranges from 0.2 to 0.8 m³ / h, the water pump outlet pressure varies from approximately 1.26 to 1.25 MPa, and the fluctuation value is approximately 0.01 MPa.

[0148] According to the curve provided by the spray gun manufacturer, within approximately ±12.5% ​​of the middle section of the spray gun performance curve, the pressure fluctuation range of ammonia water is 0.3 Bar (equivalent to 0.03 MPa). Therefore, it meets the requirement that the change in pump operating head within the SNCR system's flow operating range be less than 4m.

[0149] In a 72-hour comparative test conducted by the company, under the premise of ensuring the same nitrogen oxide emission concentration below 100 mg / m3 and using a fixed number of 8 spray guns, the average ammonia consumption was approximately 0.85 m3 / h when one water pump was running, and approximately 0.65 m3 / h when four water pumps were running.

[0150] In a 72-hour comparative test conducted by the company, under the premise of ensuring the same ammonia consumption of 0.65 m3 / h and using a fixed number of 8 spray guns, the nitrogen oxide emission concentration was approximately 145 mg / m3 when one water pump was running, and approximately 87 mg / m3 when four water pumps were running.

[0151] In a 72-hour comparative test conducted by the company with four water pumps running and nitrogen oxide emission concentrations below 100 mg / m³, the average ammonia consumption was approximately 0.65 m³ / h when the number of spray guns was fixed at eight. The average ammonia consumption was approximately 0.61 m³ / h when the number of spray guns was calculated by taking the flow rate (l / h) / 70 (l / h) determined by the SNCR system, rounding up, and adjusting periodically.

[0152] When this method was applied to the cement clinker production line, the ammonia consumption was reduced by 0.24 m3 / h compared to when the method was not used, resulting in an annual saving of 1,728 tons of ammonia and a reduction in operating costs of 1.728 million yuan.

[0153] An information data processing terminal is used to implement the parameter control method of the above-mentioned enhanced SNCR system.

[0154] A computer-readable storage medium includes instructions that, when executed on a computer, cause the computer to perform the parameter control method of the enhanced SNCR system described above.

[0155] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented, in whole or in part, as a computer program product, the computer program product includes one or more computer instructions. When the computer program instructions are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0156] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. A method for controlling parameters of a reinforced SNCR system, the reinforced SNCR system comprising M1 water pumps, M2 injection lances, a controller for controlling the working states of the water pumps and the injection lances, which are connected in parallel with each other; characterized in that, The parameters of the M1 water pumps are the same; the parameter control method includes: S1, acquire basic parameters; the basic parameters include pressure H at the lowest flow rate within the range of ±12.5% of the middle section flow rate change of the lance performance curve low , pressure H at the highest flow rate within the range of ±12.5% of the middle section flow rate change of the lance performance curve high , lower limit Q of the flow rate change range of the SNCR system denitration agent low , upper limit Q of the flow rate change range of the SNCR system denitration agent high , water pump friction s; S2. Basic parameter analysis; The number of water pumps N that are turned on can be obtained using the following formula: The number of spray guns, n, that are activated is obtained using the following formula: n = denitrification agent dosage Q / the midpoint flow rate q of the spray gun performance curve, rounded up to the nearest integer; S3. The SNCR system is enhanced by controlling the number of water pumps N and the number of spray guns n in S2.

2. The method of claim 1, wherein the parameters of the intensified SNCR system are controlled by, The variation in pump operating head within the flow range of the enhanced SNCR system is less than 4m.

3. The method of claim 2, wherein the parameters of the intensified SNCR system are controlled by, The head pressure is 0.04 MPa.

4. The parameter control method for enhancing the SNCR system according to claim 1, characterized in that, n is not less than 4.

5. A parameter control system for an enhanced SNCR system, the enhanced SNCR system comprising M1 water pumps, M2 spray guns, and a controller for controlling the operating states of the water pumps and spray guns connected in parallel; characterized in that, The parameters of the M1 water pumps are the same; the parameter control system includes: a base parameter acquisition module; the base parameters include pressure H at the lowest flow rate within a range of ±12.5% of the middle section flow rate of the lance performance curve low pressure H at the highest flow rate within a range of ±12.5% of the middle section flow rate of the lance performance curve high lower limit Q of the flow rate variation range of the SNCR system denitration agent low upper limit Q of the flow rate variation range of the SNCR system denitration agent high water pump friction s; Basic parameter analysis module; The number of water pumps N that are turned on can be obtained using the following formula: The number of spray guns, n, that are activated is obtained using the following formula: n = denitrification agent dosage Q / the midpoint flow rate q of the spray gun performance curve, rounded up to the nearest integer; Control module: The SNCR system is enhanced by controlling the number of water pumps N and the number of spray guns n in the basic parameter analysis module.

6. The parameter control system for the enhanced SNCR system according to claim 5, characterized in that, The variation in pump operating head within the flow range of the enhanced SNCR system is less than 4m.

7. The parameter control system for the enhanced SNCR system according to claim 6, characterized in that, The head pressure is 0.04 MPa.

8. The parameter control system for the enhanced SNCR system according to claim 5, characterized in that, n is not less than 4.

9. An information data processing terminal, characterized in that, A parameter control method for implementing the enhanced SNCR system according to any one of claims 1-4.

10. A computer-readable storage medium, characterized in that, Includes instructions that, when executed on a computer, cause the computer to perform a parameter control method for implementing the enhanced SNCR system according to any one of claims 1-4.

Images