Desulfurization system method for treating low-purity gypsum product of power plant

Abstract

A method of a desulfurization system for treating low-purity gypsum products of a power plant comprises the following steps: investigating and comparing a plurality of groups of desulfurization systems, and determining the desulfurization system with low-purity gypsum products caused by poor reaction effect in an absorption tower; analyzing the reason for poor reaction effect in the absorption tower, and performing multi-stage disassembly analysis on the reason according to the reaction process in the reaction tower to form a plurality of disassembly reasons; sampling, investigating and confirming the disassembly reason formed in each reaction process, analyzing the influence effect of each disassembly reason on the reflection in the absorption tower, and screening out main influence factors; a correction strategy and a correction target are made according to the main factors, and effect detection is carried out after the correction strategy is implemented. According to the method, the desulfurization system with low gypsum product purity caused by poor reaction effect in the absorption tower can be accurately determined, various reasons in the absorption tower are disassembled and analyzed, the reason of poor reaction in the absorption tower can be accurately found, and the problem of low gypsum product purity caused by poor reaction effect in the absorption tower is solved.

Description

Technical Field

[0001] The invention relates to the technical field of power plant desulfurization, and in particular to a method for treating a desulfurization system of a power plant with low purity of gypsum products. Background Art

[0002] During the operation of the desulfurization system, all indicators in the gypsum should be strictly controlled to ensure that the purity of the gypsum is qualified. The purity of gypsum has a great impact on the system. If it is too low, it will affect the activity of the limestone slurry and the density of the slurry in the absorption tower, which will be manifested in the increase of limestone consumption in the system, the increase of power consumption of the slurry circulation pump, and the difficulty of gypsum dehydration, which will eventually increase equipment wear, resulting in reduced efficiency and increased failure rate of the desulfurization system. The poor reaction effect in the absorption tower is an important reason for the low purity of the gypsum product in the power plant. It is necessary to accurately analyze the reasons for the poor reaction effect in the absorption tower in order to reasonably propose methods to control the desulfurization system with low purity of gypsum products. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To achieve the above object, the present invention proposes a method for treating a desulfurization system of a power plant with low purity of gypsum products, comprising the following steps:

[0005] S1. Investigate and compare multiple desulfurization systems to identify the desulfurization system with low gypsum product purity due to poor reaction effect in the absorption tower;

[0006] S2. Analyze the reasons for the poor reaction effect in the absorption tower, and conduct multi-stage disassembly analysis of the reasons according to the reaction process in the reaction tower to form multiple disassembly reasons;

[0007] S3. Sampling and investigation are conducted to confirm the disassembly reasons formed in each reaction process, and the influence of each disassembly reason on the reaction in the absorption tower is analyzed to screen out the main influencing factors;

[0008] S4. Formulate corrective measures and corrective targets for major factors, and test the effectiveness of corrective measures after implementation.

[0009] The present invention can accurately determine the desulfurization system in which the purity of the gypsum product is low due to the poor reaction effect in the absorption tower, and split and analyze the various reasons in the absorption tower, so as to accurately find the cause of the poor reaction in the absorption tower, so as to make targeted corrections and solve the problem of low purity of the gypsum product due to the poor reaction effect in the absorption tower.

[0010] Optionally, the S1 includes:

[0011] S11. Through investigation and comparison of multiple desulfurization systems in the power plant, the desulfurization system with low gypsum product purity was identified;

[0012] S12. Conduct multiple batches of random inspections and analysis on the gypsum products in the desulfurization system with low purity, and classify and analyze the reasons for the low gypsum purity of different batches of gypsum products to verify that the low purity of the gypsum products in the desulfurization system is caused by the poor reaction effect of the absorption tower.

[0013] Furthermore, in S12, in order to eliminate the influence of factors outside the reaction tower on the concentration of gypsum products, the system inlet SO of the desulfurization system with low gypsum purity is 2 Multiple batches of random inspections were conducted to analyze the concentration exceeding the standard, the inlet dust concentration exceeding the standard, and the chemical instrument failure, and the reasons for the low gypsum purity of different batches of gypsum products were classified and analyzed, and the reasons for the S12 step were classified and counted simultaneously to verify that the low purity of the gypsum product of the desulfurization system is caused by the poor reaction effect of the absorption tower.

[0014] Further, in S2, when the cause is analyzed by multi-stage disassembly according to the reaction process in the reaction tower, the reaction process in the reaction tower includes a dissolution process, an absorption process, an oxidation process, a crystallization process and wastewater discharge, and the disassembly cause corresponding to each process is as follows:

[0015] Dissolution process, the cause disassembly and analysis process includes: unqualified limestone slurry fineness, unqualified limestone slurry density;

[0016] During the absorption process, the reasons for the disassembly and analysis process include: low pH value of the slurry in the absorption tower, insufficient liquid-gas ratio in the desulfurization system, and poor spraying effect of the slurry circulation pump;

[0017] The reasons for the oxidation process include: insufficient oxidation air volume, high pH value of the absorption tower slurry;

[0018] The crystallization process, the cause disassembly and analysis process includes: the density of the absorber slurry is low;

[0019] Wastewater discharge, the cause analysis process includes: insufficient wastewater treatment volume and insufficient sludge discharge volume.

[0020] Furthermore, in S3, according to the disassembly reasons formed in step S2, sampling investigation is conducted on the disassembly reasons of the dissolution process, including sampling investigation on the density and fineness of the limestone slurry. The sampling standard for investigation is: the concentration of the limestone slurry is controlled at 1200-1300 kg / m 3 ; The fineness of limestone must ensure that the screening rate of 250 mesh sieve is greater than 95%.

[0021] Furthermore, in said S3, according to the disassembly reasons formed in step S2, the disassembly reasons of the absorption process are investigated, including sampling investigation of the pH value of the absorption tower slurry, the liquid-gas ratio of the desulfurization system, and statistical analysis of the spraying effect of the slurry circulation pump, wherein:

[0022] The sampling standard for the pH value survey of the absorber slurry is: the pH value of the absorber slurry is not less than 5.0;

[0023] The sampling standard for the liquid-gas ratio survey of the desulfurization system is: the liquid-gas ratio of the limestone-gypsum desulfurization method is not less than 15L / m 3 ;

[0024] The statistical analysis of the spraying effect of the slurry circulation pump includes: comparing the operating parameters of the slurry circulation pump with the parameters during the system trial operation, and by changing the operating current of the circulation pump, statistically analyzing the situation in which the outlet pressure decreases as the operating current of the circulation pump increases, and conducting on-site investigation and confirmation based on the statistical results.

[0025] Furthermore, in said S3, according to the disassembly reasons formed in step S2, sampling investigation is conducted on the disassembly reasons of the oxidation process, including sampling investigation on the pH value of the absorption tower slurry and statistical analysis on the oxidation air volume, wherein:

[0026] The sampling survey standards for the pH value of the absorber slurry include: the pH value of the absorber slurry is not higher than 5.8 and must not fluctuate violently, and the pH value and the unit load meet a linear relationship;

[0027] The statistical analysis of the oxidation air volume includes statistical calculation of the oxidation air volume and the inlet flue gas volume of the desulfurization system for several consecutive months to obtain the ratio of the actual value to the theoretical value of the oxidation air volume. The ratio of the actual value to the theoretical value of the amount of oxygen required for the oxidation reaction is not less than 2.5.

[0028] Furthermore, in said S3, according to the disassembly reasons formed in step S2, sampling investigation is conducted on the disassembly reasons of the crystallization process, including sampling investigation on the density of the absorber slurry. The sampling investigation standard for the pH value of the absorber slurry is: the density of the absorber slurry is controlled at 1100-1160 kg / m 3 between.

[0029] Furthermore, in S3, based on the dismantling reasons formed in step S2, a sampling survey is conducted on the dismantling reasons for wastewater discharge, including a sampling survey on the wastewater treatment volume and the sludge discharge volume. The survey standard is: the weekly operation time of the wastewater pump shall not be less than 14 hours, and the weekly sludge discharge amount shall not be less than 9 trucks / week.

[0030] Furthermore, in S4, the corrective measures and corrective targets for different main influencing factors are formulated as follows:

[0031] When the pH value of the absorption tower does not meet the requirements,

[0032] Corrective measures: Maintain the pH value of the slurry between 5.0 and 5.8, and try to keep it linearly related to the unit load to avoid sudden changes in pH value;

[0033] Correction target: pH value qualification rate is not less than 95%, and pH value and load meet the basic linear relationship;

[0034] When the circulation pump spray atomization effect is poor,

[0035] Corrective measures: Reduce the operating time of the problematic slurry circulation pump, and give priority to starting other slurry circulation pumps when the outlet SO2 does not exceed the standard;

[0036] Correction target: The operation time of the problematic slurry circulation pump is reduced by more than 50% compared with that before implementation;

[0037] When the wastewater treatment volume and sludge discharge volume are insufficient,

[0038] Corrective measures: Treat wastewater as required, up to 14 hours per week, and discharge sludge as required, up to 9 truckloads per week;

[0039] Corrective target: Wastewater treatment time and sludge discharge compliance rate shall not be less than 90%.

[0040] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0042] Figure 1 A schematic diagram of the steps of a method for treating a desulfurization system of a power plant with low purity of gypsum products according to the present invention;

[0043] Figure 2 It is a schematic diagram of a limestone slurry density analysis line according to an embodiment of a method for treating a desulfurization system of a power plant with low purity of gypsum products according to the present invention;

[0044] Figure 3 It is a schematic diagram of a limestone fineness analysis line according to an embodiment of a method for treating a desulfurization system of a power plant with low purity of gypsum products according to the present invention;

[0045] Figure 4 It is a schematic diagram of a pH value adjustment range broken line according to an embodiment of a method for treating a desulfurization system of a power plant with low purity of gypsum products of the present invention;

[0046] Figure 5 It is a schematic diagram of the relationship between pH value and load according to an embodiment of a method for treating a desulfurization system of a power plant with low purity of gypsum products of the present invention;

[0047] Figure 6It is a schematic diagram of the liquid-gas ratio of a desulfurization system according to an embodiment of a method for treating a desulfurization system of a power plant with low purity of gypsum products according to the present invention;

[0048] Figure 7 It is a schematic diagram of the current and pressure change of the circulating pump according to an embodiment of a method for treating a desulfurization system of a power plant with low purity of gypsum products of the present invention;

[0049] Figure 8 It is a schematic diagram of the oxidation air volume of the desulfurization system according to an embodiment of a method for treating a desulfurization system of a power plant with low purity of gypsum products of the present invention;

[0050] Fig. 9 It is a statistical schematic diagram of wastewater treatment time according to an embodiment of a method for treating a desulfurization system of a power plant with low purity of gypsum products according to the present invention;

[0051] Fig.10 It is a statistical diagram of sludge discharge quantity according to an embodiment of a method for treating a desulfurization system of a power plant with low purity of gypsum products according to the present invention; DETAILED DESCRIPTION

[0052] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0053] The present invention provides a method for treating a desulfurization system of a power plant with low purity of gypsum products. Figures 1 to 10 Elaborate in detail.

[0054] A method for treating a desulfurization system of a power plant with low purity of gypsum products, comprising the following steps:

[0055] S1. Investigate and compare multiple desulfurization systems to identify the desulfurization system with low gypsum product purity due to poor reaction effect in the absorption tower;

[0056] S2. Analyze the reasons for the poor reaction effect in the absorption tower, and conduct multi-stage disassembly analysis of the reasons according to the reaction process in the reaction tower to form multiple disassembly reasons;

[0057] S3. Sampling and investigation are conducted to confirm the disassembly reasons formed in each reaction process, and the influence of each disassembly reason on the reaction in the absorption tower is analyzed to screen out the main influencing factors;

[0058] S4. Formulate corrective measures and corrective targets for major factors, and test the effectiveness of corrective measures after implementation.

[0059] The present invention can accurately determine the desulfurization system in which the purity of the gypsum product is low due to the poor reaction effect in the absorption tower, and split and analyze the various reasons in the absorption tower, so as to accurately find the cause of the poor reaction in the absorption tower, so as to make targeted corrections and solve the problem of low purity of the gypsum product due to the poor reaction effect in the absorption tower.

[0060] In some embodiments, the S1 includes:

[0061] S11. Through investigation and comparison of multiple desulfurization systems in the power plant, the desulfurization system with low gypsum product purity was identified;

[0062] S12. Conduct multiple batches of random inspections and analysis on the gypsum products in the desulfurization system with low purity, and classify and analyze the reasons for the low gypsum purity of different batches of gypsum products to verify that the low purity of the gypsum products in the desulfurization system is caused by the poor reaction effect of the absorption tower.

[0063] In some embodiments, in S12, in order to eliminate the influence of factors outside the reaction tower on the concentration of the gypsum product, the system inlet SO of the desulfurization system with low gypsum purity is 2 Multiple batches of random inspections were conducted to analyze the concentration exceeding the standard, the inlet dust concentration exceeding the standard, and the chemical instrument failure, and the reasons for the low gypsum purity of different batches of gypsum products were classified and analyzed, and the reasons for the S12 step were classified and counted simultaneously to verify that the low purity of the gypsum product of the desulfurization system is caused by the poor reaction effect of the absorption tower.

[0064] In some embodiments, in S2, when the cause is analyzed by multi-stage disassembly according to the reaction process in the reaction tower, the reaction process in the reaction tower includes a dissolution process, an absorption process, an oxidation process, a crystallization process, and wastewater discharge, and the disassembly cause corresponding to each process is as follows:

[0065] Dissolution process, the cause disassembly and analysis process includes: unqualified limestone slurry fineness, unqualified limestone slurry density;

[0066] During the absorption process, the reasons for the disassembly and analysis process include: low pH value of the slurry in the absorption tower, insufficient liquid-gas ratio in the desulfurization system, and poor spraying effect of the slurry circulation pump;

[0067] The reasons for the oxidation process include: insufficient oxidation air volume, high pH value of the absorption tower slurry;

[0068] The crystallization process, the cause disassembly and analysis process includes: the density of the absorber slurry is low;

[0069] Wastewater discharge, the cause analysis process includes: insufficient wastewater treatment volume and insufficient sludge discharge volume.

[0070] In some embodiments, in S3, according to the disassembly reasons formed in step S2, sampling investigation is conducted on the disassembly reasons of the dissolution process, including sampling investigation on the density and fineness of the limestone slurry. The sampling standard for the investigation is: the concentration of the limestone slurry is controlled at 1200-1300 kg / m 3 ; The fineness of limestone must ensure that the screening rate of 250 mesh sieve is greater than 95%.

[0071] In some embodiments, in said S3, according to the disassembly reasons formed in step S2, the disassembly reasons of the absorption process are investigated, including sampling investigation of the pH value of the absorption tower slurry, the liquid-gas ratio of the desulfurization system, and statistical analysis of the spraying effect of the slurry circulation pump, wherein:

[0072] The sampling standard for the pH value survey of the absorber slurry is: the pH value of the absorber slurry is not less than 5.0;

[0073] The sampling standard for the liquid-gas ratio survey of the desulfurization system is: the liquid-gas ratio of the limestone-gypsum desulfurization method is not less than 15L / m 3 ;

[0074] The statistical analysis of the spraying effect of the slurry circulation pump includes: comparing the operating parameters of the slurry circulation pump with the parameters during the system trial operation, and by changing the operating current of the circulation pump, statistically analyzing the situation in which the outlet pressure decreases as the operating current of the circulation pump increases, and conducting on-site investigation and confirmation based on the statistical results.

[0075] In some embodiments, in said S3, according to the disassembly reasons formed in step S2, sampling investigation is conducted on the disassembly reasons of the oxidation process, including sampling investigation on the pH value of the absorption tower slurry and statistical analysis on the oxidation air volume, wherein:

[0076] The sampling survey standards for the pH value of the absorber slurry include: the pH value of the absorber slurry is not higher than 5.8 and must not fluctuate violently, and the pH value and the unit load meet a linear relationship;

[0077] The statistical analysis of the oxidation air volume includes statistical calculation of the oxidation air volume and the inlet flue gas volume of the desulfurization system for several consecutive months to obtain the ratio of the actual value to the theoretical value of the oxidation air volume. The ratio of the actual value to the theoretical value of the amount of oxygen required for the oxidation reaction is not less than 2.5.

[0078] In some embodiments, in S3, according to the disassembly reasons formed in step S2, sampling investigation is conducted on the disassembly reasons of the crystallization process, including sampling investigation on the density of the absorber slurry. The sampling investigation standard for the pH value of the absorber slurry is: the density of the absorber slurry is controlled at 1100-1160 kg / m 3 between.

[0079] In some embodiments, in S3, based on the disassembly reasons formed in step S2, a sampling survey is conducted on the disassembly reasons for wastewater discharge, including a sampling survey on the wastewater treatment volume and the sludge discharge volume. The survey standard is: the weekly wastewater pump operation time shall not be less than 14 hours, and the weekly sludge discharge amount shall not be less than 9 trucks / week.

[0080] In some embodiments, in S4, corrective measures and corrective targets for different major influencing factors are formulated as follows:

[0081] When the pH value of the absorption tower does not meet the requirements,

[0082] Corrective measures: Maintain the pH value of the slurry between 5.0 and 5.8, and try to keep it linearly related to the unit load to avoid sudden changes in pH value;

[0083] Correction target: pH value qualification rate is not less than 95%, and pH value and load meet the basic linear relationship;

[0084] When the circulation pump spray atomization effect is poor,

[0085] Corrective measures: Reduce the operating time of the problematic slurry circulation pump, and give priority to starting other slurry circulation pumps when the outlet SO2 does not exceed the standard;

[0086] Correction target: The operation time of the problematic slurry circulation pump is reduced by more than 50% compared with that before implementation;

[0087] When the wastewater treatment volume and sludge discharge volume are insufficient,

[0088] Corrective measures: Treat wastewater as required, up to 14 hours per week, and discharge sludge as required, up to 9 truckloads per week;

[0089] Corrective target: Wastewater treatment time and sludge discharge compliance rate shall not be less than 90%.

[0090] After the correction is completed, the power consumption of the circulating pump, limestone consumption and gypsum purity of the corrected unit are investigated and compared to determine whether the correction target has been achieved. If not, correction must be performed again according to the above steps.

[0091] In one embodiment, specific data is provided to supplement the explanation of the verification process in step S3.

[0092] (1) The limestone slurry sampling data is as follows:

[0093]

[0094] Form a line chart such as Figure 2 and Figure 3As shown, the average density of limestone slurry is 1241.3kg / m3; the qualified rate is 90%; the average 250-mesh screening rate of limestone slurry is 96.81%; the qualified rate is 100%, which means that the density and fineness of limestone slurry are not the main influencing factors.

[0095] (2) The data of pH value and unit load in the absorption tower are as follows:

[0096] frequency Load(MW) pH frequency Load(MW) pH 1 500 5.21 11 550 5.62 2 550 5.35 12 350 5.92 3 450 5.86 13 500 4.91 4 350 5.33 14 400 5.39 5 550 5.03 15 450 5.44 6 400 4.95 16 500 5.18 7 350 5.32 17 400 4.89 8 450 5.44 18 450 5.21 9 500 5.84 19 350 5.47 10 400 5.27 20 550 5.38

[0097] Form a line graph of pH value adjustment range as follows Figure 4 As shown in the figure, it can be seen that the pH value of the absorption tower fluctuates greatly, and the qualified rate of pH value in the sampling point is 70%, which does not meet the requirements;

[0098] The relationship between pH value and unit load is shown in the figure below: Figure 5 As shown, the linearity between pH value and unit load in actual operation is very poor and does not meet the operation adjustment requirements;

[0099] In other words, it can be determined that the pH value of the absorption tower not meeting the requirements is the main influencing factor causing the low purity of the gypsum product.

[0100] (3) Statistics on the liquid-gas ratio of the desulfurization system. During the statistics, the flow rate of the slurry circulation pump was 11260m 3 / h, the statistical data is as follows:

[0101] date Unit load Flue gas flow Number of circulation pumps Liquid-gas ratio July 8 405MW 1335 3 25.3 July 19 301MW 1197 2 18.8 August 5 503MW 1706 3 19.8 August 18 449MW 1467 3 22.8 September 3 587MW 1782 4 25.3 September 22 498MW 1720 3 19.6 October 10 305MW 1206 3 28.0 October 28 352MW 1284 3 26.3 November 7 452MW 1385 3 24.3 November 23 497MW 1686 4 26.7

[0102] The liquid-gas ratio line graph of the desulfurization system is formed as follows: Figure 6 As shown in the chart, it can be seen that the system liquid-gas ratio is significantly higher than the standard value of 15 (the liquid-gas ratio of limestone-gypsum desulfurization is not less than 15L / m 3 ), the liquid-gas ratio meets the operating requirements, that is, insufficient liquid-gas ratio is not the main influencing factor causing the low purity of gypsum products.

[0103] (4) Statistics on the spraying effect of the slurry circulation pump are as follows:

[0104]

[0105] The changes in the circulating pump current and pressure are tabulated and observed to form a table such as Figure 7 The circulation pump current and pressure change diagram is shown.

[0106] Depend on Figure 6We can see that the current and pressure of the #4A slurry circulation pump have changed significantly compared with the system debugging, indicating that the spray atomization effect of the #4A slurry circulation pump has decreased. From the above data, we can confirm that the spray atomization effect of the #4A slurry circulation pump has decreased. That is, the poor spray atomization effect of the circulation pump is the main factor causing the low purity of the gypsum product.

[0107] (5) Statistical analysis of the oxidation air volume is carried out, and the statistical data are as follows:

[0108] date Inlet SO2 Flue gas flow Oxidation air volume Practical / Theoretical July 8 2310 1335 24435 4.75 July 19 2714 1197 24513 4.53 August 5 2625 1706 24482 3.28 August 18 1318 1467 24461 7.60 September 3 1720 1782 24594 4.81 September 22 1875 1720 24715 4.59 October 10 2629 1206 24613 4.66 October 28 1735 1284 24559 6.61 November 7 2018 1385 24631 5.29 November 23 2310 1686 24435 3.76

[0109] The desulfurization system oxidation air volume line chart is formed as follows: Figure 8 As shown in the figure, it can be seen that the oxidation air volume of the desulfurization system is significantly higher than the theoretical value by 2.5 times, and the oxidation air volume load is within the standard of the regulations. In other words, insufficient oxidation air volume is not the main factor causing the low purity of gypsum products.

[0110] (6) A statistical survey was conducted on the slurry density in the absorber during the operation of the dehydration system. The statistical data are shown in the following table:

[0111] date Density (kg / m3) in conclusion date Density (kg / m3) in conclusion July 8 1121 qualified September 22 1120 qualified July 19 1126 qualified October 10 1131 qualified August 5 1118 qualified October 28 1123 qualified August 18 1120 qualified November 7 1114 qualified September 3 1125 qualified November 23 1128 qualified

[0112] The statistical data show that the gypsum cyclone meets the requirements of the regulations in terms of operation mode. In other words, the low density of the absorption tower slurry is not the main factor causing the low purity of the gypsum product.

[0113] (7) The wastewater treatment volume and sludge discharge volume were investigated and analyzed. The survey data are as follows:

[0114] Wastewater treatment(h) Mud removal (car) Wastewater treatment(h) Mud removal (car) Week 1 11.3 5 Week 6 13.0 7 Week 2 13.7 7 Week 7 14.5 6.5 Week 3 11.7 5.5 Week 8 10.5 6 Week 4 12.5 6 Week 9 11.7 9 Week 5 9.7 6.5 Week 10 12.3 8

[0115] Generate a radar icon to analyze wastewater treatment conditions such as Fig. 9 and Fig.10 As shown in the figure, it can be seen intuitively from the statistical chart that the wastewater treatment time and sludge discharge volume do not meet the standards, which affects the gypsum quality of the desulfurization system and reduces the purity of the gypsum. In other words, insufficient wastewater treatment volume and sludge discharge volume are the main factors affecting the low purity of gypsum products.

[0116] That is, after the analysis in step S3, the main factors causing the low purity of the gypsum product include: the pH value of the absorption tower does not meet the requirements; the spray atomization effect of the circulating pump is poor; and the wastewater treatment volume and sludge discharge volume are insufficient.

[0117] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0118] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0119] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0120] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0121] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0122] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for treating a desulfurization system of a power plant with low purity of gypsum products, characterized in that: The following steps are involved: S1. Investigate and compare multiple desulfurization systems to identify the desulfurization system with low gypsum product purity due to poor reaction effect in the absorption tower; S2. Analyze the reasons for the poor reaction effect in the absorption tower, and conduct multi-stage disassembly analysis of the reasons according to the reaction process in the reaction tower to form multiple disassembly reasons; S3. Sampling and investigation are conducted to confirm the disassembly reasons formed in each reaction process, and the influence of each disassembly reason on the reaction in the absorption tower is analyzed to screen out the main influencing factors; S4. Formulate corrective measures and corrective targets for major factors, and test the effectiveness of corrective measures after implementation.

2. A method for treating a desulfurization system of a power plant with low purity of gypsum products as claimed in claim 1, characterized in that: The S1 includes: S11. Through investigation and comparison of multiple desulfurization systems in the power plant, the desulfurization system with low gypsum product purity was identified; S12. Conduct multiple batches of random inspections and analysis on the gypsum products in the desulfurization system with low purity, and classify and analyze the reasons for the low gypsum purity of different batches of gypsum products to verify that the low purity of the gypsum products in the desulfurization system is caused by the poor reaction effect of the absorption tower.

3. A method for treating a desulfurization system of a power plant with low purity of gypsum products as claimed in claim 2, characterized in that: In the S12, in order to eliminate the influence of factors outside the reaction tower on the concentration of the gypsum product, multiple batches of random inspections and analyses are conducted on the excessive SO2 concentration at the system inlet, the excessive dust concentration at the inlet, and the chemical instrument failure of the desulfurization system with low gypsum purity. The reasons for the low gypsum purity of gypsum products in different batches are classified and analyzed, and the reasons are classified and counted synchronously with the reasons in step S12 to verify that the low purity of the gypsum product in the desulfurization system is caused by the poor reaction effect of the absorption tower.

4. A method for treating a desulfurization system of a power plant with low purity of gypsum products as claimed in claim 1, characterized in that: In S2, when the cause is analyzed in multiple stages according to the reaction process in the reaction tower, the reaction process in the reaction tower includes a dissolution process, an absorption process, an oxidation process, a crystallization process, and wastewater discharge, and the disassembly cause corresponding to each process is as follows: Dissolution process, the cause disassembly and analysis process includes: unqualified limestone slurry fineness, unqualified limestone slurry density; During the absorption process, the reasons for the disassembly and analysis process include: low pH value of the slurry in the absorption tower, insufficient liquid-gas ratio in the desulfurization system, and poor spraying effect of the slurry circulation pump; The reasons for the oxidation process include: insufficient oxidation air volume, high pH value of the absorption tower slurry; The crystallization process, the cause disassembly and analysis process includes: the density of the absorber slurry is low; Wastewater discharge, the cause analysis process includes: insufficient wastewater treatment volume and insufficient sludge discharge volume.

5. A method for treating a desulfurization system of a power plant with low purity of gypsum products as claimed in claim 4, characterized in that: In S3, according to the disassembly reasons formed in step S2, sampling investigation is conducted on the disassembly reasons of the dissolution process, including sampling investigation on the density and fineness of the limestone slurry. The sampling standard for investigation is: the concentration of the limestone slurry is controlled at 1200-1300kg / m 3 ; The fineness of limestone must ensure that the screening rate of 250 mesh sieve is greater than 95%.

6. A method for treating a desulfurization system of a power plant with low purity of gypsum products as claimed in claim 4, characterized in that: In said S3, according to the disassembly reasons formed in step S2, the disassembly reasons of the absorption process are investigated, including sampling investigation of the pH value of the absorption tower slurry, the liquid-gas ratio of the desulfurization system, and statistical analysis of the spraying effect of the slurry circulation pump, wherein: The sampling standard for the pH value survey of the absorber slurry is: the pH value of the absorber slurry is not less than 5.0; The sampling standard for the liquid-gas ratio survey of the desulfurization system is: the liquid-gas ratio of the limestone-gypsum desulfurization method is not less than 15L / m 3 ; The statistical analysis of the spraying effect of the slurry circulation pump includes: comparing the operating parameters of the slurry circulation pump with the parameters during the system trial operation, and by changing the operating current of the circulation pump, statistically analyzing the situation in which the outlet pressure decreases as the operating current of the circulation pump increases, and conducting on-site investigation and confirmation based on the statistical results.

7. A method for treating a desulfurization system of a power plant with low purity of gypsum products as claimed in claim 4, characterized in that: In said S3, according to the disassembly reasons formed in step S2, sampling investigation is conducted on the disassembly reasons of the oxidation process, including sampling investigation on the pH value of the absorption tower slurry and statistical analysis on the oxidation air volume, wherein: The sampling survey standards for the pH value of the absorber slurry include: the pH value of the absorber slurry is not higher than 5.8 and must not fluctuate violently, and the pH value and the unit load meet a linear relationship; The statistical analysis of the oxidation air volume includes statistical calculation of the oxidation air volume and the inlet flue gas volume of the desulfurization system for several consecutive months to obtain the ratio of the actual value to the theoretical value of the oxidation air volume. The ratio of the actual value to the theoretical value of the amount of oxygen required for the oxidation reaction is not less than 2.

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8. A method for treating a desulfurization system of a power plant with low purity of gypsum products as claimed in claim 4, characterized in that: In S3, according to the disassembly reasons formed in step S2, sampling investigation is conducted on the disassembly reasons of the crystallization process, including sampling investigation on the density of the absorber slurry. The sampling investigation standard for the pH value of the absorber slurry is: the density of the absorber slurry is controlled at 1100-1160 kg / m 3 between.

9. A method for treating a desulfurization system of a power plant with low purity of gypsum products as claimed in claim 4, characterized in that: In S3, based on the dismantling reasons formed in step S2, a sampling survey is conducted on the dismantling reasons for wastewater discharge, including a sampling survey on the wastewater treatment volume and the sludge discharge volume. The survey standard is: the weekly wastewater pump operation time shall not be less than 14 hours, and the weekly sludge discharge amount shall not be less than 9 trucks / week.

10. A method for treating a desulfurization system of a power plant with low purity of gypsum products as claimed in claim 1, characterized in that: In S4, the corrective measures and corrective targets for different major influencing factors are formulated as follows: When the pH value of the absorption tower does not meet the requirements, Corrective measures: Maintain the pH value of the slurry between 5.0 and 5.8, and try to keep it linearly related to the unit load to avoid sudden changes in pH value; Correction target: pH value qualification rate is not less than 95%, and pH value and load meet the basic linear relationship; When the circulation pump spray atomization effect is poor, Corrective measures: Reduce the operating time of the problematic slurry circulation pump, and give priority to starting other slurry circulation pumps when the outlet SO2 does not exceed the standard; Correction target: The operation time of the problematic slurry circulation pump is reduced by more than 50% compared with that before implementation; When the wastewater treatment volume and sludge discharge volume are insufficient, Corrective measures: Treat wastewater as required, up to 14 hours per week, and discharge sludge as required, up to 9 truckloads per week; Corrective target: Wastewater treatment time and sludge discharge compliance rate shall not be less than 90%.

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