Catalyst life prediction and evaluation calculation method based on periodic denitrification performance optimization

Abstract

The present invention discloses a catalyst life prediction and evaluation calculation method based on periodic denitration performance optimization, including the following steps: after replacing the catalyst, record it as the initial time, calculate the denitration reactor potential at the initial time according to the NOx and NH3 concentrations in the inlet and outlet flue gas; calculate the actual denitration reactor potential at the initial time by the actual NOx and NH3 concentrations in the inlet and outlet flue gas tested by the performance test at the initial time; after the catalyst has been running for a period of time, perform a performance test, calculate the actual denitration reactor potential at the current time, and calculate the attenuation index of the catalyst chemical performance at the current time in combination with the actual average denitration reactor potential at the initial time to determine whether the catalyst needs to be replaced. The present invention evaluates the catalyst life through denitration performance data, which is of great benefit to improving the operating economy of the denitration system and can provide reliable life prediction management for the in-service replacement of the catalyst.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalyst detection, and in particular relates to a catalyst life prediction and evaluation calculation method based on periodic denitration performance optimization. Background Art

[0002] As the national requirements for nitrogen oxide emission standards for coal-fired power plants become increasingly stringent, most coal-fired power plants must reduce NOx emissions to 50mg / m 3 Below, the NOx concentration at the SCR outlet of the key control area should be reduced to 30mg / m 3 As the NOx emission concentration limit at the SCR outlet is further reduced, the denitration efficiency of the SCR device is further improved, and the efficiency of the denitration system is as high as over 88%, and even over 93% for some units. The requirement for improving the overall efficiency of the denitration system is that the SCR device is equipped with more catalysts. Under ultra-low emission conditions, the SCR device is generally equipped with 2 to 3 layers of catalysts, and 4 layers of catalysts in special cases. Taking a 300MW unit as an example, the volume of each layer of catalyst is generally not less than 100m 3 , arranged in three layers, the volume of catalyst in each boiler is up to 600m 3 Above, and with the increase of unit capacity, the volume of catalyst increases exponentially. After the denitrification catalyst is put into operation, the life of the catalyst continues to decrease due to the influence of chemical life and operating conditions. The life of the catalyst under normal operating conditions is 3 to 5 years. During the entire life cycle of the denitrification catalyst, it is particularly important to master the performance of the denitrification catalyst for the replacement of the catalyst. The laboratory tests currently carried out can effectively evaluate the performance of the catalyst monomer to a certain extent, but in order to consider factors such as on-site flue gas mixing and ash accumulation, it is particularly important to carry out denitrification catalyst performance evaluation based on field tests to improve the reliability of denitrification life management.

[0003] At present, in order to improve the uniformity of the ammonia injection system of the denitrification device, the denitrification system performance is regularly optimized during the normal operation of the denitrification system, and the ammonia escape concentration and efficiency of the denitrification system are tested. The data from regular tests are used to provide effective data support for the life assessment of the denitrification system.

[0004] In order to obtain data such as the operating life of denitrification catalysts, the current mainstream methods use methods such as fitting nitrogen oxide and denitrification efficiency test data or calculating existing catalyst monomer data. However, the measurement results of nitrogen oxide and denitrification efficiency data alone are easily affected by the layout of the measurement system and the data fitting method, which can easily lead to large deviations. In addition, the catalyst monomer test and analysis method is limited by the acquisition of monomers and cannot be analyzed. It is impossible to consider the impact of on-site operating conditions on catalyst life. At present, there is no calculation method for catalyst life prediction and evaluation based on periodic performance optimization.

[0005] Chinese patent document CN107194154A discloses a method for evaluating and calculating an SCR denitration catalyst. First, the SCR denitration catalyst evaluation coefficient is calculated, and a continuous curve of the SCR denitration catalyst evaluation coefficient changing with time is made to analyze the operation of the catalyst, providing data support for the adjustment of the SCR denitration catalyst. However, this calculation method considers the effects of denitration NOx concentration and ammonia slip on the catalyst evaluation coefficient separately, but does not consider the correlation between the two. The reliability of the prediction method of the SCR denitration catalyst evaluation coefficient model needs to be verified.

[0006] Chinese patent document CN111044668A discloses an online prediction method for the catalyst life of an SCR denitration system. According to the actual ammonia-nitrogen molar ratio at the catalyst inlet, the relationship between the denitration efficiency and the catalyst activity is established, and the catalyst deactivation in different regions is taken into account, so that when the overall catalyst life expires, it can determine which layer of catalyst to replace, and accurately evaluate and calculate the catalyst replacement volume. Although the patent takes into account the impact of the denitration efficiency in different regions, it does not consider the impact of ammonia slip at the denitration outlet on the catalyst life, and the predicted denitration catalyst life is less accurate.

[0007] Chinese patent document CN110554135A proposes a method for calculating the replacement volume of SCR denitration catalyst based on activity detection. The present invention detects the activity of each layer of catalyst in the denitration device and calculates the activity attenuation coefficient, so that the whole is connected to the differential pressure measuring elements arranged outside the flue, and can stably and reliably measure the flue gas flow. The equipment installation has low requirements for the straight pipe steady flow section, is not easy to be blocked, and is easy to maintain. However, the activity of each layer of catalyst must be determined by sampling and analyzing the catalysts in each layer in the SCR device. The sampling and analysis must be done when the unit is shut down, and it has certain limitations for guiding the life management of the catalyst.

[0008] Chinese patent document CN110310714A proposes a method for predicting the remaining life of a denitrification catalyst in a coal-fired power plant. The method collects the measured catalyst relative activity data of the coal-fired power plant, determines whether the obtained catalyst relative activity data is equidistant measurement data, processes the obtained catalyst relative activity data to make it equidistant, constructs a catalyst relative activity degradation state space model, and uses the obtained catalyst activity degradation state space model combined with a random filtering algorithm to predict the catalyst remaining activity. However, regular catalyst inspection is required and must be combined with unit maintenance. The prediction model is relatively complex and has low operability.

[0009] Chinese patent document CN109411031A proposes a method for predicting the remaining life of an in-service catalyst based on actual operating conditions. The in-service denitrification catalyst is sampled and tested to measure the current catalyst K 1, collect data such as the average flue gas flow rate V and average coal consumption mass M of the unit in the coal-fired power plant, substitute the collected and repaired data into the formula, calculate the correction coefficient λ, and obtain the deactivation curve of the in-service denitrification catalyst. According to the manufacturer's designed catalyst threshold k y , calculate the remaining life of the catalyst in service t s However, this method only considers the effect of the performance decay of the catalyst itself on the catalyst life, and does not consider the effect of the actual flue gas conditions on the catalyst ash accumulation and deactivation on the catalyst life, which has certain limitations.

[0010] Chinese patent document CN109603517A proposes a method for predicting the life of SCR denitration catalysts in thermal power plants and optimizing replacement strategies, including: establishing a mathematical model based on the deactivation equations of each layer of catalysts, the denitration efficiency equation, the reactor denitration efficiency equation, and the ammonia nitrogen molar ratio equation of the second and third layer catalyst inlets, and predicting the catalyst life according to the mathematical model. However, this method does not consider optimizing the performance of the existing reactor and improving the performance of the existing catalyst, and the accuracy of the prediction is greatly affected by the mathematical model.

[0011] In summary, among the various methods currently disclosed for predicting and evaluating the life of catalysts in denitrification systems, except for some patents that use actual flue gas as a test condition to evaluate catalyst performance, most methods use methods based on catalyst activity detection to evaluate catalyst performance. The calculation process is too complicated, and due to the limitations of the model, model parameters need to be corrected for different types of units. The calculation method for predicting the life of the catalyst is not very applicable. In the existing disclosed patents, there is a lack of methods for predicting the performance life of the catalyst based on periodic denitrification performance optimization and measured data on the performance of the denitrification system. Summary of the invention

[0012] In order to solve the technical problems existing in the prior art, the purpose of the present invention is to provide a catalyst life prediction and evaluation calculation method based on periodic denitration performance optimization.

[0013] In order to achieve the above purpose and the above technical effect, the technical solution adopted by the present invention is:

[0014] The catalyst life prediction and evaluation calculation method based on periodic denitration performance optimization includes the following steps:

[0015] Retrieve the operation data of the initial moment of catalyst operation, record the initial moment after catalyst replacement, calculate the denitration efficiency at the initial moment after catalyst replacement and the denitration reactor potential at the initial moment, calculate the actual denitration efficiency and the actual denitration reactor potential at the initial moment according to the initial test parameters of the performance test at the initial moment, and then obtain the actual average denitration reactor potential at the initial moment. After the catalyst has been running for a period of time, perform regular ammonia injection optimization and adjustment, adjust the ammonia injection grid opening and ammonia injection system control parameters, and improve the uniformity of the ammonia nitrogen molar ratio of the denitration device. Subsequently, perform performance testing and calculate the actual denitration reactor potential at the current moment, thereby calculating the average value of the denitration reactor potential at the current moment and combining the actual average denitration reactor potential at the initial moment to calculate the attenuation index of the catalyst chemical performance at the current moment. Calculate the remaining life of the catalyst according to the threshold of the initial catalyst attenuation index provided by the catalyst manufacturer to determine whether the catalyst needs to be replaced.

[0016] Furthermore, the denitration efficiency at the initial moment and the denitration reactor potential at the initial moment are calculated according to the following steps:

[0017] After the new catalyst is installed, the NOx concentration C in the flue gas at the inlet of the SCR reactor is measured at the initial time. NOx,in,d , NOx concentration in outlet flue gas C NOx,out,d NH in the inlet flue gas 3 Concentration C NH3,in,d and NH in the outlet flue gas 3 Concentration C NH3,out,d And calculate the denitrification efficiency η at the initial moment d and the denitrification reactor potential P at the initial time d , the calculation formula is as follows:

[0018]

[0019] η d ={(C NOx,in,d -C NOx,out,d )*100} / C NOx,in,d .

[0020] Furthermore, the actual denitration efficiency and the actual denitration reactor potential at the initial moment are calculated according to the following steps:

[0021] The actual NOx concentration C in the inlet flue gas at the initial moment of the test NOx,in,0,i , Actual NOx concentration in outlet flue gas C NOx,out,0,i , Actual NH in the inlet flue gas 3 Concentration C NH3,in,0,i and the actual ammonia escape concentration C NH3,out,0,i And calculate the actual denitrification efficiency η at the initial moment 0,iand the actual denitrification reactor potential P at the initial moment 0,i , the calculation formula is as follows:

[0022]

[0023] η o,i ={(C NOx,in,0,i -C NOx,out,0,i )*100} / C NOx,in,0,i

[0024] Among them, i=1,2,..n, n is 2 to 4.

[0025] Further, according to the actual denitrification reactor potential P at the initial moment obtained in step 2) 0,i Calculate the actual average denitrification reactor potential P at the initial time 0 , the calculation formula is as follows:

[0026] P 0 =average(P 0,1 , P 0,2 ,…,P 0,i )

[0027] Among them, i=1,2,..n, n is 2 to 4.

[0028] Furthermore, the actual denitration reactor potential at the current moment is the denitration reactor potential Pτ when the catalyst operation time reaches τ. ,i , calculated according to the following steps:

[0029] When the catalyst operation time reaches time τ, regular optimization and adjustment of ammonia injection is carried out. By optimizing and adjusting the existing ammonia injection grid, the potential of the existing device is improved. Multiple rounds of performance tests are carried out. The test results are based on high load and the denitrification reactor potential Pτ at time τ is obtained. ,i , the calculation formula is as follows:

[0030]

[0031] Among them, C NOx,in,τ,i is the NOx concentration in the flue gas at the inlet of the SCR reactor at time τ; C NOx,out,τ,i is the NOx concentration in the flue gas at the outlet of the SCR reactor at time τ; C NH3,in,τ,i is the NH in the flue gas at the inlet of the SCR reactor at time τ 3 Concentration, C NH3,out,τ,i is the NH in the flue gas at the outlet of the SCR reactor at time τ 3 Concentration; i=1,2,..n, n is 3~6.

[0032] Furthermore, the average value of the denitration reactor potential at the current moment is the denitration reactor potential Pτ when the catalyst operation time reaches τ, and the calculation formula is as follows:

[0033] Pτ=average(Pτ ,1 , Pτ ,2 ,…,Pτ ,i )

[0034] Among them, i=1,2,..n, n is 3 to 6.

[0035] Furthermore, the attenuation index Λτ of the catalyst chemical performance when the catalyst operation time is τ is calculated according to the following formula:

[0036] Λτ=Pτ / P 0

[0037] If Λτ>0.6~0.65, the chemical life of the catalyst has not expired and can be used normally;

[0038] If Λτ≤0.6~0.65, the chemical life of the catalyst has expired and needs to be replaced or regenerated;

[0039] If Λτ≤0.6~0.65, the remaining chemical life L can be calculated by the denitrification reactor potential Pτ, and the calculation formula is as follows:

[0040] L = τ*(P τ -P Λ0 ) / (P 0 -P τ )

[0041] Among them, P Λ0 =Λ max *P 0 , the maximum decay index value of the catalyst chemical performance Λ max =0.6~0.65, which can be selected according to the value recommended by the catalyst manufacturer.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The present invention discloses a catalyst life prediction and evaluation calculation method based on periodic denitration performance optimization, comprising the following steps: after the catalyst is replaced, it is recorded as the initial time, and according to the NOx concentration in the inlet flue gas, the NOx concentration in the outlet flue gas and the NH 3 The concentration is used to calculate the denitrification reactor potential at the initial moment; the actual NOx concentration in the inlet flue gas, the actual NOx concentration in the outlet flue gas and the actual NH 3The concentration is used to calculate the actual denitration reactor potential at the initial moment; after the catalyst has been running for a period of time, regular ammonia injection optimization and adjustment are carried out to adjust the ammonia injection grid opening and the ammonia injection system control parameters to improve the uniformity of the ammonia nitrogen molar ratio of the denitration device, and then a performance test is carried out to calculate the actual denitration reactor potential at the current moment, and the attenuation index of the catalyst chemical performance at the current moment is calculated in combination with the actual denitration reactor potential at the initial moment, and then the attenuation index is used to determine whether the catalyst needs to be replaced. The catalyst life prediction and evaluation calculation method based on regular denitration performance optimization provided by the present invention evaluates the existing catalyst life through the denitration performance data provided by the denitration performance test, and maximizes the denitration system performance through ammonia injection optimization, which is of great benefit to improving the operating economy of the denitration system and can provide reliable life prediction management for the in-service replacement of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the measuring point positions of the present invention;

[0045] Figure 2 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0046] The present invention is described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0047] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0048] like Figure 1-2 As shown, the catalyst life prediction and evaluation calculation method based on periodic denitration performance optimization includes the following steps:

[0049] First, retrieve the operation data of the catalyst at the initial time of operation and calculate the denitration reactor potential P at the initial time after the catalyst is replaced. d , calculate the actual denitrification reactor potential P at the initial moment according to the initial test parameters 0,i , and then the actual average denitrification reactor potential P at the initial moment is obtained 0After the catalyst has been running for a period of time, the NOx concentration distribution in each area is calculated according to the existing measured data of the denitration system performance to adjust the ammonia grid opening and the ammonia injection system control parameters to improve the uniformity of the ammonia nitrogen molar ratio of the denitration device. After the operation is optimized, a performance evaluation test is carried out to obtain the denitration reactor potential Pτ at the current moment. ,i , where i = 1, 2, ..., n, where n represents the number of performance evaluation tests under high load, thereby calculating the average value P of the denitrification reactor potential at the current moment τ , according to P τ and P 0 The attenuation index of the catalyst chemical performance at the current moment is calculated, and the remaining life of the catalyst is calculated according to the threshold of the initial catalyst attenuation index λ provided by the catalyst manufacturer (the threshold of λ is generally selected to be 0.6 to 0.65).

[0050] The calculation formula for the denitrification reactor potential based on the actual denitrification device inlet and outlet NOx concentration and ammonia escape concentration is as follows:

[0051] Denitrification efficiency

[0052] Ammonia nitrogen molar ratio

[0053] Denitrification Reactor Potential

[0054] Among them, C NOx,in To convert to standard state, dry basis, 6% O 2 NOx concentration in the flue gas at the inlet of the SCR reactor under 3 ;

[0055] C NOx,out To convert to standard state, dry basis, 6% O 2 NOx concentration in the flue gas at the outlet of the SCR reactor under 3 ;

[0056] C NH3,out To convert to standard state, dry basis, 6% O 2 NH in the flue gas from the SCR reactor 3 Concentration, i.e. ammonia escape concentration, mg / m 3 ;

[0057] C NH3,in To convert to standard state, dry basis, 6% O 2 NH in the flue gas at the inlet of the SCR reactor 3 Concentration, mg / m 3 ;

[0058] η is denitrification efficiency, %;

[0059] M R is the ammonia nitrogen molar ratio (NH 3 / NOx), %;

[0060] M NO2 NO 2 Molar mass, g / mol;

[0061] M NH3 For NH 3 Molar mass, g / mol.

[0062] The catalyst life prediction and evaluation calculation method based on periodic denitration performance optimization provided by the present invention specifically includes the following steps:

[0063] 1) After the new catalyst is installed, record it as the initial time, and design the NOx concentration C in the flue gas at the inlet of the SCR reactor NOx,in,d , NOx concentration in outlet flue gas C NOx,out,d NH in the inlet flue gas 3 Concentration C NH3,in,d and NH in the outlet flue gas 3 Concentration C NH3,out,d To calculate the denitrification efficiency η at the initial time d and denitrification reactor potential P d , the entrance and exit measuring points are as follows Figure 1 As shown, the calculation formula is as follows:

[0064]

[0065] η d ={(C NOx,in,d -C NOx,out,d )*100} / C NOx,in,d

[0066]

[0067] 2) Actual NOx concentration C in the inlet flue gas measured by the performance test at the initial moment NOx,in,0,i , Actual NOx concentration in outlet flue gas C NOx,out,0,i , Actual NH in the inlet flue gas 3 Concentration C NH3,in,0,i and the actual ammonia escape concentration C NH3,out,0,i To calculate the actual denitrification efficiency η at the initial moment 0,i and the actual denitrification reactor potential P at the initial moment 0,i , the calculation formula is as follows:

[0068]

[0069] η o,i ={(CNOx,in,0,i -C NOx,out,0,i )*100} / C NOx,in,0,i

[0070]

[0071] Wherein, i = 1, 2, .. n, and n is generally preferably 2 to 4;

[0072] 3) According to the actual denitrification reactor potential P at the initial moment obtained in step 2) 0,i Calculate the actual average denitrification reactor potential P at the initial time 0 , the calculation formula is as follows:

[0073] P 0 =average(P 0,1 , P 0,2 ,…,P 0,i )

[0074] Wherein, i = 1, 2, .. n, n is generally 2 to 4;

[0075] 4) When the catalyst operation time reaches τ (unit: h), regular optimization and adjustment of ammonia injection is carried out. By optimizing and adjusting the existing ammonia injection grid, the potential of the existing device is improved, and multiple rounds of performance tests are carried out. The test results are based on high load, and the denitrification reactor potential Pτ at time τ is obtained. ,i , the calculation formula is as follows:

[0076]

[0077] η o,i ={(C NOx,in,τ,i -C NOx,out,τ,i )*100} / C NOx,in,τ,i

[0078]

[0079] Among them, C NOx,in,τ,i is the NOx concentration in the flue gas at the inlet of the SCR reactor at time τ; C NOx,out,τ,i is the NOx concentration in the flue gas at the outlet of the SCR reactor at time τ; C NH3,in,τ,i is the NH in the flue gas at the inlet of the SCR reactor at time τ 3 Concentration, C NH3,out,τ,i is the NH in the flue gas at the outlet of the SCR reactor at time τ 3 Concentration; i = 1, 2, .. n, n is generally 3 to 6;

[0080] 5) The denitrification reactor potential Pτ at time τ obtained according to step 4) ,i The denitration reactor potential Pτ is calculated when the catalyst operation time is τ, and the calculation formula is as follows:

[0081] Pτ=average(Pτ ,1 , Pτ ,2 ,…,Pτ ,i )

[0082] Wherein, i = 1, 2, .. n, n is generally 3 to 6;

[0083] 6) Evaluate whether the existing catalyst has reached its chemical lifespan, and calculate the decay index Λτ of the catalyst chemical performance when the catalyst operation time is τ according to the following formula:

[0084] Λτ=Pτ / P 0

[0085] If Λτ>0.6~0.65, the chemical life of the catalyst has not expired and can be used normally;

[0086] If Λτ≤0.6~0.65, the chemical life of the catalyst has expired and needs to be replaced or regenerated;

[0087] 7) Calculate the remaining chemical life of the catalyst according to the decay index Λτ of the catalyst chemical performance when the catalyst runs for τ:

[0088] If Λτ≤0.6~0.65, the remaining chemical life L can be calculated by the denitrification reactor potential Pτ, and the calculation formula is as follows:

[0089] L = τ*(P τ -P Λ0 ) / (P 0 -P τ )

[0090] Among them, P Λ0 =Λ max *P 0 , the maximum decay index value of the catalyst chemical performance Λ max =0.6~0.65, which can be selected according to the value recommended by the catalyst manufacturer.

[0091] Example 1

[0092] like Figure 1-2 As shown in the figure, the catalyst life prediction and evaluation calculation method based on periodic denitration performance optimization takes the catalyst life prediction and evaluation of the denitration system of a 630MW wall-type hedge combustion boiler as an example, which specifically includes the following steps:

[0093] 1) The design inlet NOx concentration of the denitrification system is 400 mg / m 3 , install three-layer catalyst, and design outlet NOx concentration is 25mg / m 3The ammonia escape concentration is 3.0 μL / L, and the inlet and outlet measurement points are as follows: Figure 1 The maximum attenuation index value of the catalyst provided by the catalyst manufacturer is Λ max =0.65, initial design denitrification device potential P d =3.45;

[0094] 2) After the new catalyst was installed, performance tests ST-01 to ST-03 were carried out. The test results are shown in Table 1. The unit loads all reached the designed rated loads. According to the measured inlet and outlet NOx concentrations and outlet NH 3 Concentration calculation three times initial moment measured denitrification device potential P 0,1 =3.44, P 0,2 =3.47, P 0,3 =3.48, and then calculate the average denitrification device potential P 0 =average(P 0,1 , P 0,2 , P 0,3 )=3.46,P d With P 0 The values ​​are close, so select P 0 =3.46. If the data deviation is large, multiple rounds of testing or verification of the catalyst's design performance parameters should be considered;

[0095] Table 1

[0096]

[0097]

[0098] 3) The catalyst runs for nearly τ1 = 3000h, and an ammonia injection optimization test is carried out according to the on-site arrangement. As shown in Table 2 below, the denitrification reactor potential P before ammonia injection optimization adjustment τ1,T-01 =3.25. After multiple rounds of adjustments, the calibration test T-05~T-07 was carried out under rated load. The three measured denitrification device potentials at time τ1 were: P τ1,T-05 =3.33, P τ1,T-06 =3.30, P τ1,T-07 =3.34, and then calculate the average denitrification device potential P τ1 =average(P τ1,T-05 , P τ1,T-06 , P τ1,T-07 )=3.32, according to the data comparison P τ1 With P τ1,T-01 It can be seen that the potential of the reactor can be improved by about 2% by injecting ammonia at time τ1, and P τ1 =3.32, calculate the attenuation index of the catalyst chemical performance at this time τ1=0.96, predicting the remaining life of the catalyst L τ1 =22950h;

[0099] Table 2

[0100]

[0101] 4) The catalyst runs for nearly τ2 = 18000h, and an ammonia injection optimization test is carried out according to the site arrangement. As shown in Table 3 below, the denitrification reactor potential P before the ammonia injection optimization adjustment τ2,T-01 =2.71. After multiple rounds of adjustments, the calibration test T-06~T-08 was carried out under rated load. The three measured denitrification device potentials at time τ1 were: P τ2,T-06 =2.79, P τ2,T-07 =2.78, P τ2,T-08 =2.74, and then calculate the average denitrification device potential P τ1 =2.77, according to data comparison P τ1 With P τ1,T-01 Compared with the previous results, the potential of the reactor can be improved by about 2% by injecting ammonia at time τ1, and P τ2 =2.77, calculate the attenuation index of the catalyst chemical performance at this time τ1 =0.80, predicting the remaining life of the catalyst L τ2 =10229h;

[0102] Table 3

[0103]

[0104] 5) The catalyst runs for nearly τ3 = 30000h, and an ammonia injection optimization test is carried out according to the site arrangement. As shown in Table 4 below, the denitrification reactor potential P before the ammonia injection optimization adjustment τ3,T-01 =2.14. After multiple rounds of adjustments, the calibration test T-06~T-08 was carried out under rated load. The three measured denitrification device potentials at time τ1 were: P τ1,T-04 =2.19, P 0,T-05 =2.23, P 0,T-06 =2.18, and then calculate the average denitrification device potential P τ1 =2.20, according to the data comparison P τ3 With P τ3,T-01 Compared with the previous results, the potential of the optimized reactor by injecting ammonia at time τ1 was increased by about 3%, and P τ3 =2.20, calculate the attenuation index of the catalyst chemical performance at this time τ3 =0.64, due to Λ τ3 <Λ max , operating value τ3 = 30000h, catalyst regeneration or replacement is required.

[0105] Table 4

[0106]

[0107] The present invention evaluates the life of the existing catalyst through the denitration performance data provided by the denitration performance test, which is of great benefit to improving the operating economy of the denitration system and can provide a reliable life prediction management method for the in-service replacement of the catalyst.

[0108] Parts or structures not specifically described in the present invention may adopt existing technologies or existing products and will not be described in detail here.

[0109] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A catalyst life prediction and evaluation calculation method based on periodic denitration performance optimization, characterized in that: The following steps are involved: Retrieve the operation data of the initial moment of the catalyst operation, record the initial moment after the catalyst is replaced, calculate the denitration efficiency at the initial moment after the catalyst is replaced and the denitration reactor potential at the initial moment, calculate the actual denitration efficiency and the actual denitration reactor potential at the initial moment according to the initial test parameters of the performance test at the initial moment, and then obtain the actual average denitration reactor potential at the initial moment. After the catalyst has been running for a period of time, perform regular ammonia injection optimization adjustment, adjust the ammonia injection grid opening and the ammonia injection system control parameters, and improve the uniformity of the ammonia nitrogen molar ratio of the denitration device. Then perform a performance test to calculate the actual denitration reactor potential at the current moment, thereby calculating the average value of the denitration reactor potential at the current moment and combining the actual average denitration reactor potential at the initial moment to calculate the attenuation index of the catalyst chemical performance at the current moment, calculate the remaining life of the catalyst according to the threshold value of the initial catalyst attenuation index provided by the catalyst manufacturer, and judge whether the catalyst needs to be replaced; After the new catalyst is installed, the NOx concentration C in the flue gas at the inlet of the SCR reactor is measured at the initial time. NOx,in,d , NOx concentration in outlet flue gas C NOx,out,d 、NH3 concentration in inlet flue gas C NH3,in,d and NH3 concentration in outlet flue gas C NH3,out,d And calculate the denitrification efficiency η at the initial moment d and denitrification reactor potential P d , the calculation formula is as follows: the d ={(C NOx,in,d -C NOx,out,d )*100} / C NOx,in,d The actual NOx concentration C in the inlet flue gas at the initial moment of the test NOx,in,0,i , Actual NOx concentration in outlet flue gas C NOx,out,0,i , Actual NH3 concentration in inlet flue gas C NH3,in,0,i and the actual ammonia escape concentration C NH3,out,0,i And calculate the actual denitrification efficiency η at the initial moment 0,i and the actual denitrification reactor potential P at the initial moment 0,i , the calculation formula is as follows: the o,i ={(C NOx,in,0,i -C NOx,out,0,i )*100} / C NOx,in,0,i Wherein, i=1,2,..n, n is 2 to 4; According to the actual denitrification reactor potential P at the initial moment 0,i Calculate the actual average denitrification reactor potential P0 at the initial moment, the calculation formula is as follows: P0=average(P 0,1 ,P 0,2 ,…,P 0,i ) Wherein, i=1,2,..n, n is 2 to 4; When the catalyst operation time reaches time τ, regular optimization and adjustment of ammonia injection is carried out. By optimizing and adjusting the existing ammonia injection grid, the potential of the existing device is improved. Multiple rounds of performance tests are carried out. The test results are based on high load and the denitrification reactor potential Pτ at time τ is obtained. ,i , the calculation formula is as follows: Wherein, i=1,2,..n, n is 3 to 6; According to the denitrification reactor potential Pτ at time τ ,i The denitration reactor potential Pτ is calculated when the catalyst operation time is τ, and the calculation formula is as follows: Pτ=average(Pτ ,1 ,Pτ ,2 ,…,Pτ ,i ) Wherein, i=1,2,..n, n is 3 to 6; To evaluate whether the existing catalyst has reached its chemical lifespan, the attenuation index Λτ of the catalyst chemical performance when the catalyst operating time is τ is calculated according to the following formula: Λτ=Pτ / P0 If Λτ>0.6~0.65, the chemical life of the catalyst has not expired and can be used normally; If Λτ≤0.6~0.65, the chemical life of the catalyst has expired and needs to be replaced or regenerated; The remaining chemical life of the catalyst is calculated based on the attenuation index Λτ of the catalyst chemical performance when the catalyst operating time is τ: If Λτ≤0.6~0.65, the remaining chemical life L is calculated by the denitrification reactor potential Pτ, and the calculation formula is as follows: L=τ*(P τ -P Λ0 ) / (P0-P τ ) Among them, P Λ0 =Λ max *P0, the maximum attenuation index of the catalyst's chemical properties Λ max =0.6~0.65, selected according to the value recommended by the catalyst manufacturer.

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