Method for determining ammonium bisulfate production in coal-fired power plants and method for determining deposition risk in air preheaters

Abstract

The application provides a method for determining ammonium bisulfate yield in a coal-fired power plant and a method for determining deposition risk of ammonium bisulfate in an air preheater. The method for determining ammonium bisulfate yield comprises: obtaining SO3 content and denitration flue gas volume of denitration outlet flue gas of a denitration reactor corresponding to the air preheater of the target coal-fired power plant, and then determining equivalent over-ammonia content of the denitration outlet of the air preheater corresponding to the denitration reactor and distribution proportion of over-ammonia in the denitration outlet flue gas; obtaining a generation rate calculation model of ammonium bisulfate, determining the generation rate of ammonium bisulfate, and then determining the generation amount of ammonium bisulfate. The method for determining deposition risk of ammonium bisulfate in the air preheater comprises: determining the generation amount of ammonium bisulfate by using the method for determining ammonium bisulfate yield; obtaining an initial formation temperature calculation model of ammonium bisulfate, determining the initial formation temperature of ammonium bisulfate; and obtaining an air preheater internal ammonium bisulfate deposition risk value calculation model, and determining the air preheater internal ammonium bisulfate deposition risk value.

Description

Technical Field

[0001] The invention relates to a method for determining the output of ammonium bisulfate in a coal-fired power plant and a method for determining the deposition risk of ammonium bisulfate in an air preheater of a coal-fired power plant. Background Art

[0002] Coal-fired power plants commonly use selective catalytic reduction (SCR) technology for flue gas denitrification. While removing NOx from the flue gas, it also produces byproducts: ammonium sulfate (AB) and ammonium bisulfate (ABS). ABS is highly viscous and corrosive, and when heated to the appropriate temperature, it can easily cause ash blockage in downstream denitrification equipment. The melting point of ammonium bisulfate is 147°C, which means it will condense on the cold side of the air preheater, causing blockage and an increase in the operating pressure differential.

[0003] The generation and production of ammonium bisulfate are closely related to factors such as flue gas temperature, ammonia escape content in flue gas, and SO3 content in flue gas. However, the following problems exist in the actual measurement points of coal-fired power plants, making it impossible to measure, monitor, and evaluate the generation and deposition of ammonium bisulfate: (1) Real-time monitoring of flue gas SO3 concentration is difficult; (2) Ammonia escape online instruments are generally inaccurate in measurement and the installation location is not representative; (3) The specific quantitative relationship between ammonium bisulfate and the above factors is unclear. Therefore, establishing a method to quantitatively determine the amount of ammonium bisulfate produced by coal-fired power plants will help to grasp the generation of ammonium bisulfate in coal-fired power plants under different operating conditions in real time, thereby guiding the safe and stable operation of the units. Summary of the Invention

[0004] The present invention aims to provide a method for quantitatively determining the production of ammonium bisulfate in a coal-fired power plant. Another object of the present invention is to provide a method for predicting the risk of ammonium bisulfate deposition in an air preheater of a coal-fired power plant.

[0005] In order to achieve the above objectives, the present invention provides the following four technical solutions.

[0006] In a first aspect, the present invention provides a method for determining the output of ammonium bisulfate in a coal-fired power plant, wherein the method comprises:

[0007] Obtain the SO3 content and denitrification flue gas volume in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant;

[0008] Combined with the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, determine the converted overspray ammonia content at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant and the distribution ratio of the overspray ammonia in the denitrification outlet flue gas;

[0009] Obtain a calculation model for the generation rate of ammonium bisulfate, which is a calculation model for the generation rate of ammonium bisulfate with respect to the flue gas temperature at the air preheater outlet, the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the SO3 content in the flue gas at the denitrification outlet; determine the generation rate of ammonium bisulfate in the air preheater of the target coal-fired power plant based on the calculation model for the generation rate of ammonium bisulfate, in combination with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet;

[0010] Based on the generation rate of ammonium bisulfate in the air preheater of the target coal-fired power plant, combined with the denitrification flue gas volume of the corresponding denitrification reactor of the air preheater of the target coal-fired power plant, the SO3 content in the flue gas at the denitrification outlet, the converted overspray ammonia content at the denitrification outlet and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, the generation amount of ammonium bisulfate in the air preheater of the target coal-fired power plant is determined.

[0011] In a second aspect, the present invention provides a method for determining the risk of ammonium bisulfate deposition in an air preheater of a coal-fired power plant, wherein the method comprises:

[0012] The amount of ammonium bisulfate generated in the air preheater of the target coal-fired power plant is determined using the above-mentioned method for determining the ammonium bisulfate production of the coal-fired power plant;

[0013] Obtaining a calculation model for the initial formation temperature of ammonium bisulfate, which is a calculation model for the initial formation temperature of ammonium bisulfate with respect to the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the SO3 content in the flue gas at the denitrification outlet; determining the initial formation temperature of ammonium bisulfate in the air preheater of the target coal-fired power plant based on the calculation model for the initial formation temperature of ammonium bisulfate in combination with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet;

[0014] A calculation model for the risk value of ammonium bisulfate deposition in the air preheater is obtained, which is a calculation model for the risk value of ammonium bisulfate deposition in the air preheater with respect to the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, the SO3 content in the flue gas at the denitrification outlet, the initial formation temperature of ammonium bisulfate, the flue gas temperature at the air preheater outlet, and the metal wall temperature at the cold end of the air preheater. Based on the calculation model for the risk of ammonium bisulfate deposition in the air preheater, combined with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the initial formation temperature of ammonium bisulfate in the air preheater, the risk value of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant is determined.

[0015] In a third aspect, the present invention provides a system for determining the production of ammonium bisulfate in a coal-fired power plant, wherein the system comprises:

[0016] The first module is used to obtain the SO3 content and denitrification flue gas volume in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant;

[0017] The second module is used to determine the overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater of the target coal-fired power plant and the distribution ratio of the overspray ammonia in the flue gas at the denitration outlet, based on the denitration flue gas volume of the denitration reactor corresponding to the air preheater of the target coal-fired power plant;

[0018] The third module is used to obtain a calculation model for the generation rate of ammonium bisulfate, which is a calculation model for the generation rate of ammonium bisulfate with respect to the flue gas temperature at the air preheater outlet, the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the SO3 content in the flue gas at the denitrification outlet. The generation rate of ammonium bisulfate in the air preheater of the target coal-fired power plant is determined based on the calculation model for the generation rate of ammonium bisulfate, in combination with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet.

[0019] The fourth module is used to determine the generation amount of ammonium bisulfate in the air preheater of the target coal-fired power plant based on the generation rate of ammonium bisulfate in the air preheater of the target coal-fired power plant, the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the SO3 content in the flue gas at the denitrification outlet, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet.

[0020] In a fourth aspect, the present invention provides a system for determining the risk of ammonium bisulfate deposition in an air preheater of a coal-fired power plant, wherein the system comprises:

[0021] The above-mentioned coal-fired power plant ammonium bisulfate production determination system, and

[0022] Module 5: A calculation model for obtaining the initial formation temperature of ammonium bisulfate, which is a calculation model for the initial formation temperature of ammonium bisulfate with respect to the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the SO3 content in the flue gas at the denitrification outlet; based on the calculation model for the initial formation temperature of ammonium bisulfate, combined with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, the initial formation temperature of ammonium bisulfate in the air preheater of the target coal-fired power plant is determined;

[0023] Module 6: used to obtain the calculation model of the risk value of ammonium bisulfate deposition in the air preheater. The model is a calculation model for the risk value of ammonium bisulfate deposition in the air preheater regarding the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, the SO3 content in the flue gas at the denitrification outlet, the initial formation temperature of ammonium bisulfate, the flue gas temperature at the air preheater outlet and the metal wall temperature at the cold end of the air preheater. Based on the calculation model of the risk of ammonium bisulfate deposition in the air preheater, combined with the SO3 content in the flue gas at the denitrification outlet of the corresponding denitrification reactor of the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet and the initial formation temperature of ammonium bisulfate in the air preheater, the risk value of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant is determined.

[0024] Compared with the existing technology, the present invention can determine the production of ammonium bisulfate during the combustion process of a coal-fired boiler and the risk of ammonium bisulfate deposition in the air preheater, and guide the safe operation of the denitrification and ammonia injection of the coal-fired unit and the air preheater. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Based on research and analysis of real-time operating parameters of coal-fired power plants, coal quality testing data from power plants, and methods specified in relevant standards, the inventors proposed the present method for determining ammonium bisulfate production in coal-fired power plants and the risk of ammonium bisulfate deposition in air preheaters. Based on the real-time SO₃ content in the flue gas, the inventors determined the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, the ammonia escape value, the initial temperature and production of ammonium bisulfate, and the risk of ammonium bisulfate deposition in the air preheater. These calculations provide a detailed understanding of ammonium bisulfate generation and deposition downstream of denitrification in coal-fired power plants, thereby guiding the safe operation of coal-fired power plant equipment, particularly air preheaters.

[0027] An embodiment of the present invention provides a method for determining the production of ammonium bisulfate in a coal-fired power plant, wherein the method comprises:

[0028] Step S1: Obtaining the SO3 content and denitrification flue gas volume in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant;

[0029] Step S2: Determine the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater of the target coal-fired power plant and the distribution ratio of the overspray ammonia in the denitration outlet flue gas based on the denitration flue gas volume of the denitration reactor corresponding to the air preheater of the target coal-fired power plant;

[0030] Step S3: Obtaining a calculation model for the generation rate of ammonium bisulfate, which is a calculation model for the generation rate of ammonium bisulfate with respect to the flue gas temperature at the air preheater outlet, the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the SO3 content in the flue gas at the denitrification outlet; determining the generation rate of ammonium bisulfate in the air preheater of the target coal-fired power plant based on the calculation model for the generation rate of ammonium bisulfate in combination with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet;

[0031] Step S4: Based on the generation rate of ammonium bisulfate in the air preheater of the target coal-fired power plant, combined with the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the SO3 content in the denitrification outlet flue gas, the denitrification outlet converted overspray ammonia content and the distribution ratio of overspray ammonia in the denitrification outlet flue gas, the generation amount of ammonium bisulfate in the air preheater of the target coal-fired power plant is determined.

[0032] Furthermore, in step S1, obtaining the SO3 content in the flue gas at the denitration outlet of the denitration reactor corresponding to the air preheater of the target coal-fired power plant includes:

[0033] Step S11: obtaining the amount of flue gas generated by the combustion of coal in the target coal-fired power plant boiler and the SO2 content in the flue gas generated by the combustion of coal in the target coal-fired power plant boiler before SO2 is converted into SO3;

[0034] Step S12: Obtain a calculation model for the conversion rate of SO2 to SO3 during the coal-fired combustion oxidation process, which is a calculation model for the conversion rate of SO2 to SO3 during the coal-fired combustion oxidation process with respect to the SO2 content; determine the conversion rate of SO2 to SO3 during the coal-fired combustion oxidation process in the target coal-fired power plant boiler based on the calculation model for the conversion rate of SO2 to SO3 during the coal-fired combustion oxidation process combined with the SO2 content in the flue gas generated by the coal-fired combustion in the target coal-fired power plant boiler before the conversion of SO2 to SO3 occurs; determine the SO3 content in the flue gas generated by the coal-fired combustion in the target coal-fired power plant boiler and the SO2 content in the flue gas generated by the coal-fired combustion in the target coal-fired power plant boiler based on the conversion rate of SO2 to SO3 during the coal-fired combustion oxidation process in the target coal-fired power plant boiler combined with the SO2 content in the flue gas generated by the coal-fired combustion in the target coal-fired power plant boiler before the conversion of SO2 to SO3 occurs;

[0035] Step S13: obtaining a calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process, which is a calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process with respect to the denitrification inlet flue gas temperature, denitrification catalyst composition parameters, denitrification catalyst activity coefficient, SO2 content in the flue gas generated by coal combustion, denitrification flue gas volume, and total geometric surface area of ​​the denitrification catalyst; determining the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant based on the calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process in combination with the SO2 content in the flue gas generated by coal combustion in the boiler of the target coal-fired power plant and the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant; determining the SO3 content generated during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant based on the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant in combination with the SO2 content in the flue gas generated by coal combustion in the boiler of the target coal-fired power plant;

[0036] Step S14: Based on the SO3 content in the flue gas generated by the coal combustion in the boiler of the target coal-fired power plant and the SO3 content generated during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, determine the SO3 content in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant.

[0037] Furthermore, in step S11, obtaining the amount of flue gas generated by the target coal-fired power plant boiler and the SO2 content in the flue gas generated by the target coal-fired power plant boiler before SO2 is converted to SO3 includes:

[0038] Step S111: Acquire coal quality data of the target coal-fired power plant boiler and real-time operating parameters of the target coal-fired power plant boiler;

[0039] Step S112: Based on the coal quality data of the target coal-fired power plant boiler and the real-time operating parameters of the target coal-fired power plant boiler, determine the standard dry flue gas volume generated by the combustion of the coal in the target coal-fired power plant boiler as the flue gas volume generated by the combustion of the coal in the target coal-fired power plant boiler;

[0040] Step S113: Based on the standard dry flue gas volume generated by the target coal-fired power plant boiler, the coal quality data of the target coal-fired power plant boiler, and the real-time operating parameters of the target coal-fired power plant boiler, determine the SO2 content in the standard dry flue gas generated by the target coal-fired power plant boiler before SO2 to SO3 conversion occurs, as the SO2 content in the flue gas generated by the target coal-fired power plant boiler before SO2 to SO3 conversion occurs;

[0041] In step S112, the standard dry flue gas volume generated by the combustion of coal in the target coal-fired power plant boiler can be determined by the following formula:

[0042] in,

[0043]

[0044] V0=0.0889×(C ar +0.375×S ar )+0.265×H ar -0.0333×O ar

[0045] Where C ar is the as-received carbon content of the coal, in %, and can be obtained from the daily coal quality tests of power plants; H ar The unit is % and the data can be obtained from the daily coal quality test of the power plant; N ar is the basic nitrogen received from coal combustion, unit: %, data can be obtained from the daily coal quality test of the power plant; S ar The total sulfur content of the coal as received, in %, can be obtained from the daily coal quality test of the power plant; ar is the base oxygen received by coal combustion, unit %, the data can be obtained from the daily coal quality test of the power plant; m is the coal combustion amount, unit t / h, which can be obtained from the DCS real-time data of the unit dial; V0 is the theoretical air volume, unit m 3 / kg; is the standard dry flue gas volume coefficient, unit: m 3 / kg; Q0 is the standard dry flue gas volume generated by coal combustion (i.e. the flue gas volume generated by coal combustion), unit: m 3 / h (standard state, dry basis, 6% oxygen content); The oxygen content at the denitrification inlet, in %, can be obtained from the DCS real-time data on the unit panel. The average value can be taken when there are multiple measurement points.

[0046] In step S113, the SO2 content in the standard dry flue gas generated by the coal combustion in the target coal-fired power plant boiler before the conversion of SO2 to SO3 occurs can be determined by the following formula:

[0047]

[0048] Where S ar The total sulfur content of the coal as received, in %, can be obtained from the daily coal quality test of the power plant; ar is the basic oxygen received by coal combustion, unit %, the data can be obtained from the daily coal quality test of the power plant; m is the coal combustion amount, unit t / h, which can be obtained from the DCS real-time data of the unit dial; Q0 is the flue gas volume generated by coal combustion, unit m 3 / h; The oxygen content at the denitrification inlet, in %, can be obtained from the DCS real-time data on the unit panel. The average value can be taken when there are multiple measurement points. It is the SO2 content in the standard dry flue gas produced by coal combustion before SO2 is converted to SO3 (i.e. the SO2 content in the flue gas produced by coal combustion), in mg / m 3 (Standard state, dry basis, 6% oxygen content).

[0049] Furthermore, in step S12, the calculation model of the conversion rate of SO2 to SO3 in the coal combustion oxidation process with respect to the SO2 content is:

[0050]

[0051] Where η 燃烧 is the conversion rate of SO2 to SO3 during coal combustion and oxidation, unit: %; The SO2 content in the flue gas produced by coal combustion before SO2 is converted to SO3, in mg / m 3 ; A is a coefficient, which can be determined by data fitting. In a specific embodiment, A is 1.73662.

[0052] Furthermore, in step S12, the SO3 content in the flue gas generated by the coal combustion in the target coal-fired power plant boiler is determined by the following formula:

[0053]

[0054] Where, The SO3 content in the flue gas produced by coal combustion, unit: mg / m 3 ; The SO2 content in the flue gas produced by coal combustion before SO2 is converted to SO3, in mg / m 3 ;η 燃烧 It is the conversion rate of SO2 to SO3 during the combustion and oxidation process of coal, unit is %.

[0055] Furthermore, in step S12, the SO2 content in the flue gas generated by the coal combustion in the target coal-fired power plant boiler is determined by the following formula:

[0056]

[0057] Where, The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ; The SO2 content in the flue gas produced by coal combustion before SO2 is converted to SO3, in mg / m 3 ;η 燃烧 It is the conversion rate of SO2 to SO3 during the combustion and oxidation process of coal, unit is %.

[0058] Furthermore, in step S13, the calculation model for the conversion rate of SO2 to SO3 during the denitration catalytic oxidation process is:

[0059]

[0060] Where η 脱硝 is the conversion rate of SO2 to SO3 during the denitration catalytic oxidation process of the air preheater corresponding to the denitration reactor, unit %; Q1 is the denitration flue gas volume of the air preheater corresponding to the denitration reactor, unit m 3 / h;T 脱硝入口 The flue gas temperature at the denitration inlet of the denitration reactor corresponding to the air preheater, in °C, can be obtained from the real-time operation data of the DCS dial; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ; S is the total geometric surface area of ​​the denitration catalyst in the denitration reactor corresponding to the air preheater, unit m 2 , which can be obtained from the performance data provided by the catalyst supplier or the test data of the power plant; f(t) is the activity coefficient of the denitration catalyst in the air preheater corresponding to the denitration reactor, which changes with the use hours. The unit is dimensionless and can be obtained from the activity coefficient change curve provided by the catalyst supplier or the activity coefficient obtained from the actual test of the power plant; C k is the content of the kth active component in the denitration catalyst of the air preheater corresponding to the denitration reactor, in %, which can be obtained from the performance data provided by the catalyst supplier or the test data of the power plant; K is the total number of active components of the denitration catalyst of the air preheater corresponding to the denitration reactor, in dimensionless units, which can be obtained from the performance data provided by the catalyst supplier or the test data of the power plant; B1, B2, B3, B4, B5, D k is the coefficient, which can be determined by data fitting;

[0061] In a specific embodiment, B1, B2, B3, B4, and B5 are respectively -0.79943, 0.00227, -1.30068, -0.00299, and 0.80849;

[0062] In a specific embodiment, the active components of the denitration catalyst are V2O5, WO3, and MoO3, the coefficient corresponding to the content of V2O5 is 0.02062, the coefficient corresponding to the content of WO3 is 0.00627, and the coefficient corresponding to the content of MoO3 is -0.00942.

[0063] Furthermore, in step S13, the SO3 generated during the denitration catalytic oxidation process of the denitration reactor corresponding to the air preheater of the target coal-fired power plant is determined by the following formula:

[0064]

[0065] Where, The SO3 content generated during the denitration catalytic oxidation process in the denitration reactor corresponding to the air preheater, in mg / m 3 ; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ;η 脱硝 It is the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater, unit: %.

[0066] Furthermore, in step S14, the SO3 content in the flue gas at the denitration outlet of the denitration reactor corresponding to the air preheater of the target coal-fired power plant is determined by the following formula:

[0067]

[0068]

[0069] Where, The SO3 content generated during the denitration catalytic oxidation process in the denitration reactor corresponding to the air preheater, in mg / m 3 ; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ; The SO3 content in the flue gas at the denitration outlet of the air preheater corresponding to the denitration reactor, in mg / m 3 ; It is the SO3 content in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater, in ppm.

[0070] Furthermore, the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant is obtained by the following method:

[0071] Based on the flue gas volume generated by coal combustion in the target coal-fired power plant boiler, determine the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant;

[0072] Among them, the denitrification flue gas volume of the air preheater corresponding to the denitrification reactor of the target coal-fired power plant can be determined by the following formula:

[0073]

[0074] Where Q i is the denitrification flue gas volume of the denitrification reactor corresponding to the i-th air preheater, unit: m 3 / h; Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; Q0 is the amount of flue gas generated by coal combustion, unit: m 3 / h; ΔP iis the operating pressure difference between the i-th air preheater and the denitrification reactor, in Pa, which can be obtained from the unit panel DCS real-time data / h; ΔP1 is the operating pressure difference between the target air preheater and the denitrification reactor, in Pa, which can be obtained from the unit panel DCS real-time data; n is the total number of air preheaters (i.e. the total number of denitrification reactors), in Pa;

[0075] For example, when the total number of air preheaters in a coal-fired power plant (i.e., the total number of denitrification reactors) is 1, Q1 = Q0

[0076] For example, when the total number of air preheaters in a coal-fired power plant (i.e. the total number of denitrification reactors) is 2,

[0077] Furthermore, the converted overspray ammonia content at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant is determined by the following formula:

[0078]

[0079] Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; The oxygen content at the denitrification inlet, in %, can be obtained from the DCS real-time data on the unit panel. The average value can be taken when there are multiple measurement points. The NOx concentration at the denitration inlet of the air preheater corresponding to the denitration reactor, in mg / m 3 (standard state, dry basis, 6% oxygen content), which can be derived from the DCS real-time data on the unit panel, and the average value can be taken when multiple measurement points are used; The NOx concentration at the denitration outlet of the air preheater corresponding to the denitration reactor, in mg / m 3 (standard state, dry basis, 6% oxygen content), can be derived from the unit panel DCS real-time data, and the average value can be taken when multiple measurement points are used; The ammonia supply flow rate of the air preheater corresponding to the denitrification reactor, in kg / h, can be obtained from the DCS real-time data on the unit panel; It is the converted overspray ammonia content at the denitrification outlet of the denitrification reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2).

[0080] Furthermore, the distribution ratio of the oversprayed ammonia of the air preheater corresponding to the denitrification reactor of the target coal-fired power plant in the denitrification outlet flue gas is determined by the following formula:

[0081]

[0082] Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; The ammonium ion content in the fly ash at the denitrification outlet of the denitrification reactor corresponding to the air preheater, in mg / kg; is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); m is the coal consumption, in t / h, which can be obtained from the real-time DCS data of the unit panel; A ar is the basic ash content of the coal, unit is %; K 脱硝烟气 It is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless.

[0083] Furthermore, the calculation model for the generation rate of ammonium bisulfate is:

[0084]

[0085] Where, K is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; 空预器出口 is the flue gas temperature at the air preheater outlet, in °C, which can be obtained from the DCS real-time data of the unit panel. The average value can be taken when there are multiple measurement points. ABS is the generation rate of ammonium bisulfate, and the unit is dimensionless; E1, E2, E3, and E4 are coefficients that can be determined by data fitting;

[0086] In a specific embodiment, E1, E2, E3, and E4 are 89.7985, -0.353, 5.233, and 9.491, respectively.

[0087] Furthermore, the amount of ammonium bisulfate generated in the air preheater of the target coal-fired power plant is determined by the following formula:

[0088]

[0089] Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; K is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; P is the SO3 content in the denitrification outlet flue gas of the air preheater corresponding to the denitrification reactor, unit: ppm; ABS is the generation rate of ammonium bisulfate, unit is dimensionless; m ABS It is the amount of ammonium bisulfate produced, in kg / h.

[0090] An embodiment of the present invention provides a method for determining the risk of ammonium bisulfate deposition in an air preheater of a coal-fired power plant, wherein the method comprises:

[0091] Step A1: Obtain the SO3 content and denitrification flue gas volume in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant;

[0092] Step A2: Based on the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, determine the converted overspray ammonia content at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant and the distribution ratio of the overspray ammonia in the denitrification outlet flue gas;

[0093] Step A3: Obtaining a calculation model for the generation rate of ammonium bisulfate, which is a calculation model for the generation rate of ammonium bisulfate with respect to the flue gas temperature at the air preheater outlet, the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the SO3 content in the flue gas at the denitrification outlet; determining the generation rate of ammonium bisulfate in the air preheater of the target coal-fired power plant based on the calculation model for the generation rate of ammonium bisulfate in combination with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet;

[0094] Step A4: Determine the amount of ammonium bisulfate generated in the air preheater of the target coal-fired power plant based on the ammonium bisulfate generation rate in the air preheater of the target coal-fired power plant, the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the SO3 content in the flue gas at the denitrification outlet, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of the overspray ammonia in the flue gas at the denitrification outlet;

[0095] Step A5: Obtaining a calculation model for the initial formation temperature of ammonium bisulfate, which is a calculation model for the initial formation temperature of ammonium bisulfate with respect to the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the SO3 content in the flue gas at the denitrification outlet; determining the initial formation temperature of ammonium bisulfate in the air preheater of the target coal-fired power plant based on the calculation model for the initial formation temperature of ammonium bisulfate in combination with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet;

[0096] Step A6: Obtain a calculation model for the risk value of ammonium bisulfate deposition in the air preheater, which is a calculation model for the risk value of ammonium bisulfate deposition in the air preheater with respect to the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, the SO3 content in the flue gas at the denitrification outlet, the initial formation temperature of ammonium bisulfate, the flue gas temperature at the air preheater outlet, and the metal wall temperature at the cold end of the air preheater; based on the calculation model for the risk value of ammonium bisulfate deposition in the air preheater and in combination with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the initial formation temperature of ammonium bisulfate in the air preheater, determine the risk value of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant.

[0097] Furthermore, in step A1, obtaining the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant includes:

[0098] Step A11: Obtaining the amount of flue gas generated by coal combustion in the target coal-fired power plant boiler and the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler before SO2 is converted into SO3;

[0099] Step A12: Obtain a calculation model for the conversion rate of SO2 to SO3 during coal combustion and oxidation, which is a calculation model for the conversion rate of SO2 to SO3 during coal combustion and oxidation with respect to the SO2 content; determine the conversion rate of SO2 to SO3 during coal combustion and oxidation in the target coal-fired power plant boiler based on the calculation model for the conversion rate of SO2 to SO3 during coal combustion and oxidation, combined with the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler before the conversion of SO2 to SO3 occurs; determine the SO3 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler and the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler based on the conversion rate of SO2 to SO3 during coal combustion and oxidation in the target coal-fired power plant boiler, combined with the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler before the conversion of SO2 to SO3 occurs;

[0100] Step A13: Obtain a calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process, which is a calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process with respect to the denitrification inlet flue gas temperature, denitrification catalyst composition parameters, denitrification catalyst activity coefficient, SO2 content in the flue gas generated by coal combustion, denitrification flue gas volume, and total geometric surface area of ​​the denitrification catalyst; based on the calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process, combined with the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler and the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, determine the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant; based on the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, combined with the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler, determine the SO3 content generated during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant;

[0101] Step A14: Based on the SO3 content in the flue gas generated by the coal combustion in the boiler of the target coal-fired power plant and the SO3 content generated during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, determine the SO3 content in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant.

[0102] Furthermore, in step A11, obtaining the amount of flue gas generated by the target coal-fired power plant boiler and the SO2 content in the flue gas generated by the target coal-fired power plant boiler before SO2 is converted to SO3 includes:

[0103] Step A111: Obtaining coal quality data of the target coal-fired power plant boiler and real-time operating parameters of the target coal-fired power plant boiler;

[0104] Step A112: Based on the coal quality data of the target coal-fired power plant boiler and the real-time operating parameters of the target coal-fired power plant boiler, determine the standard dry flue gas volume generated by the combustion of the coal in the target coal-fired power plant boiler as the flue gas volume generated by the combustion of the coal in the target coal-fired power plant boiler;

[0105] Step A113: Based on the standard dry flue gas volume generated by the target coal-fired power plant boiler, the coal quality data of the target coal-fired power plant boiler, and the real-time operating parameters of the target coal-fired power plant boiler, determine the SO2 content in the standard dry flue gas generated by the target coal-fired power plant boiler before SO2 is converted to SO3, as the SO2 content in the flue gas generated by the target coal-fired power plant boiler before SO2 is converted to SO3;

[0106] In step A112, the standard dry flue gas volume generated by the coal combustion in the target coal-fired power plant boiler can be determined by the following formula:

[0107] in,

[0108]

[0109] V0=0.0889×(C ar +0.375×S ar )+0.265×H ar -0.0333×O ar

[0110] Where C ar is the as-received carbon content of the coal, in %, and can be obtained from the daily coal quality tests of power plants; H ar The unit is % and the data can be obtained from the daily coal quality test of the power plant; N ar is the basic nitrogen received from coal combustion, unit: %, data can be obtained from the daily coal quality test of the power plant; S ar The total sulfur content of the coal as received, in %, can be obtained from the daily coal quality test of the power plant; ar is the base oxygen received by coal combustion, unit %, the data can be obtained from the daily coal quality test of the power plant; m is the coal combustion amount, unit t / h, which can be obtained from the DCS real-time data of the unit dial; V0 is the theoretical air volume, unit m 3 / kg; is the standard dry flue gas volume coefficient, unit: m 3 / kg; Q0 is the standard dry flue gas volume generated by coal combustion (i.e. the flue gas volume generated by coal combustion), unit: m 3 / h (standard state, dry basis, 6% oxygen content); The oxygen content at the denitrification inlet, in %, can be obtained from the DCS real-time data on the unit panel. The average value can be taken when there are multiple measurement points.

[0111] In step A113, the SO2 content in the standard dry flue gas generated by the coal combustion in the target coal-fired power plant boiler before the conversion of SO2 to SO3 occurs can be determined by the following formula:

[0112]

[0113] Where S ar The total sulfur content of the coal as received, in %, can be obtained from the daily coal quality test of the power plant; ar is the basic oxygen received by coal combustion, unit %, the data can be obtained from the daily coal quality test of the power plant; m is the coal combustion amount, unit t / h, which can be obtained from the DCS real-time data of the unit dial; Q0 is the flue gas volume generated by coal combustion, unit m 3 / h; The oxygen content at the denitrification inlet, in %, can be obtained from the DCS real-time data on the unit panel. The average value can be taken when there are multiple measurement points. It is the SO2 content in the standard dry flue gas produced by coal combustion before SO2 is converted to SO3 (i.e. the SO2 content in the flue gas produced by coal combustion), in mg / m 3 (Standard state, dry basis, 6% oxygen content).

[0114] Furthermore, in step A12, the calculation model of the conversion rate of SO2 to SO3 in the coal combustion oxidation process with respect to the SO2 content is:

[0115]

[0116] Where η 燃烧 is the conversion rate of SO2 to SO3 during coal combustion and oxidation, unit: %; The SO2 content in the flue gas produced by coal combustion before SO2 is converted to SO3, in mg / m 3 ; A is a coefficient, which can be determined by data fitting. In a specific embodiment, A is 1.73662.

[0117] Furthermore, in step A12, the SO3 content in the flue gas generated by the coal combustion in the target coal-fired power plant boiler is determined by the following formula:

[0118]

[0119] Where, The SO3 content in the flue gas produced by coal combustion, unit: mg / m 3 ; The SO2 content in the flue gas produced by coal combustion before SO2 is converted to SO3, in mg / m 3 ;η 燃烧 It is the conversion rate of SO2 to SO3 during the combustion and oxidation process of coal, unit is %.

[0120] Furthermore, in step A12, the SO2 content in the flue gas generated by the coal combustion in the target coal-fired power plant boiler is determined by the following formula:

[0121]

[0122] Where, The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ; The SO2 content in the flue gas produced by coal combustion before SO2 is converted to SO3, in mg / m 3 ;η 燃烧 It is the conversion rate of SO2 to SO3 during the combustion and oxidation process of coal, unit is %.

[0123] Furthermore, in step A13, the calculation model for the conversion rate of SO2 to SO3 during the denitration catalytic oxidation process is:

[0124]

[0125] Where η 脱硝 is the conversion rate of SO2 to SO3 during the denitration catalytic oxidation process of the air preheater corresponding to the denitration reactor, unit %; Q1 is the denitration flue gas volume of the air preheater corresponding to the denitration reactor, unit m 3 / h;T 脱硝入口 The flue gas temperature at the denitration inlet of the denitration reactor corresponding to the air preheater, in °C, can be obtained from the real-time operating data of the DCS dial; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ; S is the total geometric surface area of ​​the denitration catalyst in the denitration reactor corresponding to the air preheater, unit m 2 , which can be obtained from the performance data provided by the catalyst supplier or the test data of the power plant; f(t) is the activity coefficient of the denitration catalyst in the air preheater corresponding to the denitration reactor, which changes with the use hours. The unit is dimensionless and can be obtained from the activity coefficient change curve provided by the catalyst supplier or the activity coefficient obtained from the actual test of the power plant; C k is the content of the kth active component in the denitration catalyst of the air preheater corresponding to the denitration reactor, in %, which can be obtained from the performance data provided by the catalyst supplier or the test data of the power plant; K is the total number of active components of the denitration catalyst of the air preheater corresponding to the denitration reactor, in dimensionless units, which can be obtained from the performance data provided by the catalyst supplier or the test data of the power plant; B1, B2, B3, B4, B5, D k is the coefficient, which can be determined by data fitting;

[0126] In a specific embodiment, B1, B2, B3, B4, and B5 are respectively -0.79943, 0.00227, -1.30068, -0.00299, and 0.80849;

[0127] In a specific embodiment, the active components of the denitration catalyst are V2O5, WO3, and MoO3, the coefficient corresponding to the content of V2O5 is 0.02062, the coefficient corresponding to the content of WO3 is 0.00627, and the coefficient corresponding to the content of MoO3 is -0.00942.

[0128] Furthermore, in step S13, the SO3 generated during the denitration catalytic oxidation process of the denitration reactor corresponding to the air preheater of the target coal-fired power plant is determined by the following formula:

[0129]

[0130] Where, The SO3 content generated during the denitration catalytic oxidation process in the denitration reactor corresponding to the air preheater, in mg / m 3 ; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ;η 脱硝 It is the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater, unit: %.

[0131] Furthermore, in step A14, the SO3 content in the flue gas at the denitration outlet of the denitration reactor corresponding to the air preheater of the target coal-fired power plant is determined by the following formula:

[0132]

[0133]

[0134] Where, The SO3 content generated during the denitration catalytic oxidation process in the denitration reactor corresponding to the air preheater, in mg / m 3 ; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ; The SO3 content in the flue gas at the denitration outlet of the air preheater corresponding to the denitration reactor, in mg / m 3 ; It is the SO3 content in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater, in ppm.

[0135] Furthermore, the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant is obtained by the following method:

[0136] Based on the flue gas volume generated by coal combustion in the target coal-fired power plant boiler, determine the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant;

[0137] Among them, the denitrification flue gas volume of the air preheater corresponding to the denitrification reactor of the target coal-fired power plant can be determined by the following formula:

[0138]

[0139] Where Q i is the denitrification flue gas volume of the denitrification reactor corresponding to the i-th air preheater, unit: m 3 / h; Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; Q0 is the amount of flue gas generated by coal combustion, unit: m 3 / h; ΔP iis the operating pressure difference between the i-th air preheater and the denitrification reactor, in Pa, which can be obtained from the unit panel DCS real-time data / h; ΔP1 is the operating pressure difference between the target air preheater and the denitrification reactor, in Pa, which can be obtained from the unit panel DCS real-time data; n is the total number of air preheaters (i.e. the total number of denitrification reactors), in Pa;

[0140] For example, when the total number of air preheaters in a coal-fired power plant (i.e., the total number of denitrification reactors) is 1, Q1 = Q0

[0141] For example, when the total number of air preheaters in a coal-fired power plant (i.e. the total number of denitrification reactors) is 2,

[0142] Furthermore, the converted overspray ammonia content at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant is determined by the following formula:

[0143]

[0144] Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; The oxygen content at the denitrification inlet, in %, can be obtained from the DCS real-time data on the unit panel. The average value can be taken when there are multiple measurement points. The NOx concentration at the denitration inlet of the air preheater corresponding to the denitration reactor, in mg / m 3 (standard state, dry basis, 6% oxygen content), which can be derived from the DCS real-time data on the unit panel, and the average value can be taken when multiple measurement points are used; The NOx concentration at the denitration outlet of the air preheater corresponding to the denitration reactor, in mg / m 3 (standard state, dry basis, 6% oxygen content), which can be derived from the DCS real-time data on the unit panel, and the average value can be taken when multiple measurement points are used; The ammonia supply flow rate of the air preheater corresponding to the denitrification reactor, in kg / h, can be obtained from the DCS real-time data on the unit panel; It is the converted overspray ammonia content at the denitrification outlet of the denitrification reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2).

[0145] Furthermore, the distribution ratio of the oversprayed ammonia of the air preheater corresponding to the denitrification reactor of the target coal-fired power plant in the denitrification outlet flue gas is determined by the following formula:

[0146]

[0147] Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; The ammonium ion content in the fly ash at the denitrification outlet of the denitrification reactor corresponding to the air preheater, in mg / kg; is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); m is the coal consumption, in t / h, which can be obtained from the real-time DCS data of the unit panel; A ar is the basic ash content of the coal, unit is %; K 脱硝烟气 It is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless.

[0148] Furthermore, the calculation model for the generation rate of ammonium bisulfate is:

[0149]

[0150] Where, K is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; 空预器出口 is the flue gas temperature at the air preheater outlet, in °C, which can be obtained from the DCS real-time data of the unit panel. The average value can be taken when there are multiple measurement points. ABS is the generation rate of ammonium bisulfate, and the unit is dimensionless; E1, E2, E3, and E4 are coefficients that can be determined by data fitting;

[0151] In a specific embodiment, E1, E2, E3, and E4 are 89.7985, -0.353, 5.233, and 9.491, respectively.

[0152] Furthermore, the amount of ammonium bisulfate generated in the air preheater of the target coal-fired power plant is determined by the following formula:

[0153]

[0154] Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; K is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; P is the SO3 content in the denitrification outlet flue gas of the air preheater corresponding to the denitrification reactor, unit: ppm; ABS is the generation rate of ammonium bisulfate, unit is dimensionless; m ABS It is the amount of ammonium bisulfate produced, in kg / h.

[0155] Furthermore, the calculation model for the initial formation temperature of ammonium bisulfate is:

[0156]

[0157] Where, K is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; IFT is the initial formation temperature of ammonium bisulfate, in °C; F1, F2, and F3 are coefficients that can be determined by data fitting;

[0158] In a specific embodiment, F1, F2, and F3 are 194.157, 11.479, and 0.221, respectively.

[0159] Furthermore, the risk value calculation model for ammonium bisulfate deposition in the air preheater is:

[0160]

[0161] Where, K is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; IFT is the initial formation temperature of ammonium bisulfate, unit is °C; T 空预器冷端 T is the metal wall temperature at the cold end of the air preheater, in °C; 空预器出口 is the flue gas temperature at the air preheater outlet, unit: °C; P b is the risk value of ammonium bisulfate deposition in the air preheater, in %; G1 and G2 are coefficients, which can be determined by data fitting;

[0162] In a specific embodiment, G1 and G2 are 0.221 and -1.254 respectively.

[0163] Furthermore, the method further comprises:

[0164] Step A7: Based on the risk value of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant, perform a risk assessment of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant;

[0165] Further:

[0166] When the risk value of ammonium bisulfate deposition in the air preheater is less than 60%, it is considered that the amount of ammonium bisulfate generated in the air preheater has no deposition risk to the air preheater, that is, it will not significantly cause blockage of the air preheater and increase in pressure difference;

[0167] When the risk value of ammonium bisulfate deposition in the air preheater is 60%-80%, it is considered that the amount of ammonium bisulfate generated in the air preheater poses a deposition risk to the air preheater. The larger the value, the greater the deposition risk. The soot blowing frequency of the air preheater should be appropriately increased to avoid continuous deposition and clogging of the air preheater by ammonium bisulfate.

[0168] When the risk value of ammonium bisulfate deposition in the air preheater is greater than 80%, it is considered that the amount of ammonium bisulfate generated in the air preheater poses a significant deposition risk to the air preheater. The larger the value, the greater the deposition risk. While increasing the injection frequency of the air preheater and ensuring that the NOx emission concentration does not exceed the standard, the amount of ammonia sprayed for denitrification should be reduced in a timely manner, or an optimization adjustment test of ammonia spraying for denitrification should be carried out to reduce ineffective overspray of ammonia.

[0169] An embodiment of the present invention provides a system for determining the production of ammonium bisulfate in a coal-fired power plant. The system can implement the method for determining the production of ammonium bisulfate in a coal-fired power plant provided in the above embodiment. The system includes:

[0170] The first module 21 is used to obtain the SO3 content and denitrification flue gas volume in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant;

[0171] The second module 22 is used to determine the denitrification outlet converted overspray ammonia content and the distribution ratio of the overspray ammonia in the denitrification outlet flue gas based on the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant;

[0172] The third module 23 is used to obtain a calculation model for the generation rate of ammonium bisulfate, which is a calculation model for the generation rate of ammonium bisulfate with respect to the flue gas temperature at the air preheater outlet, the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the SO3 content in the flue gas at the denitrification outlet; based on the calculation model for the generation rate of ammonium bisulfate, the generation rate of ammonium bisulfate in the air preheater of the target coal-fired power plant is determined in combination with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet;

[0173] The fourth module 24 is used to determine the generation amount of ammonium bisulfate in the air preheater of the target coal-fired power plant based on the generation rate of ammonium bisulfate in the air preheater of the target coal-fired power plant, the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the SO3 content in the denitrification outlet flue gas, the denitrification outlet converted overspray ammonia content and the distribution ratio of overspray ammonia in the denitrification outlet flue gas.

[0174] Furthermore, the first module 21 includes:

[0175] The first submodule 211 is used to obtain the amount of flue gas generated by coal combustion in the target coal-fired power plant boiler and the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler before SO2 is converted into SO3;

[0176] The second submodule 212 is used to obtain a calculation model for the conversion rate of SO2 to SO3 during the coal-fired combustion oxidation process, which is a calculation model for the conversion rate of SO2 to SO3 in the coal-fired combustion oxidation process with respect to the SO2 content; based on the calculation model for the conversion rate of SO2 to SO3 during the coal-fired combustion oxidation process and the SO2 content in the flue gas generated by the coal-fired combustion in the target coal-fired power plant boiler before the conversion of SO2 to SO3 occurs, the conversion rate of SO2 to SO3 during the coal-fired combustion oxidation process of the target coal-fired power plant boiler is determined; based on the conversion rate of SO2 to SO3 during the coal-fired combustion oxidation process of the target coal-fired power plant boiler and the SO2 content in the flue gas generated by the coal-fired combustion in the target coal-fired power plant boiler before the conversion of SO2 to SO3 occurs, the SO3 content in the flue gas generated by the coal-fired combustion in the target coal-fired power plant boiler and the SO2 content in the flue gas generated by the coal-fired combustion in the target coal-fired power plant boiler are determined;

[0177] The third submodule 213 is used to obtain a calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process, which is a calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process with respect to the denitrification inlet flue gas temperature, denitrification catalyst composition parameters, denitrification catalyst activity coefficient, SO2 content in the flue gas generated by coal combustion, denitrification flue gas volume, and total geometric surface area of ​​the denitrification catalyst; based on the calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process, combined with the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler and the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant is determined; based on the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, combined with the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler, the SO3 content generated during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant is determined;

[0178] The fourth submodule 214 is used to determine the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant based on the SO3 content in the flue gas generated by the coal combustion in the boiler of the target coal-fired power plant and the SO3 content generated during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant.

[0179] Furthermore, the first submodule 211 includes:

[0180] Basic data acquisition unit 2111: used to obtain coal quality data of target coal-fired power plant boiler and real-time operating parameters of target coal-fired power plant boiler;

[0181] Flue gas volume determination submodule 2112: used to determine the standard dry flue gas volume generated by the combustion of coal in the target coal-fired power plant boiler based on the coal quality data of the target coal-fired power plant boiler and the real-time operating parameters of the target coal-fired power plant boiler, as the flue gas volume generated by the combustion of coal in the target coal-fired power plant boiler;

[0182] Coal combustion flue gas parameter determination submodule 2113: for determining, based on the standard dry flue gas volume generated by coal combustion in the target coal-fired power plant boiler, the coal quality data of the target coal-fired power plant boiler, and the real-time operating parameters of the target coal-fired power plant boiler, the SO2 content in the standard dry flue gas generated by coal combustion in the target coal-fired power plant boiler before SO2 to SO3 conversion occurs, as the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler before SO2 to SO3 conversion occurs;

[0183] The standard dry flue gas volume generated by the combustion of coal in the target coal-fired power plant boiler can be determined by the following formula:

[0184] in,

[0185]

[0186] V0=0.0889×(C ar +0.375×S ar )+0.265×H ar -0.0333×O ar

[0187] Where C ar is the as-received carbon content of the coal, in %, and can be obtained from the daily coal quality tests of power plants; H ar The unit is % and the data can be obtained from the daily coal quality test of the power plant; N ar is the basic nitrogen received from coal combustion, unit: %, data can be obtained from the daily coal quality test of the power plant; S ar The total sulfur content of the coal as received, in %, can be obtained from the daily coal quality test of the power plant; ar is the base oxygen received by coal combustion, unit %, the data can be obtained from the daily coal quality test of the power plant; m is the coal combustion amount, unit t / h, which can be obtained from the DCS real-time data of the unit dial; V0 is the theoretical air volume, unit m 3 / kg; is the standard dry flue gas volume coefficient, unit: m 3 / kg; Q0 is the standard dry flue gas volume generated by coal combustion (i.e. the flue gas volume generated by coal combustion), unit: m 3 / h (standard state, dry basis, 6% oxygen content); The oxygen content at the denitrification inlet, in %, can be obtained from the DCS real-time data on the unit panel. The average value can be taken when there are multiple measurement points.

[0188] The SO2 content in the standard dry flue gas generated by the combustion of coal in the target coal-fired power plant boiler before the conversion of SO2 to SO3 occurs can be determined by the following formula:

[0189]

[0190] Where S ar The total sulfur content of the coal as received, in %, can be obtained from the daily coal quality test of the power plant; ar is the basic oxygen received by coal combustion, unit %, the data can be obtained from the daily coal quality test of the power plant; m is the coal combustion amount, unit t / h, which can be obtained from the DCS real-time data of the unit dial; Q0 is the flue gas volume generated by coal combustion, unit m 3 / h; The oxygen content at the denitrification inlet, in %, can be obtained from the DCS real-time data on the unit panel. The average value can be taken when there are multiple measurement points. It is the SO2 content in the standard dry flue gas produced by coal combustion before SO2 is converted to SO3 (i.e. the SO2 content in the flue gas produced by coal combustion), in mg / m 3 (Standard state, dry basis, 6% oxygen content).

[0191] Furthermore, the calculation model of the conversion rate of SO2 to SO3 in the coal combustion oxidation process with respect to SO2 content is:

[0192]

[0193] Where η 燃烧 is the conversion rate of SO2 to SO3 during coal combustion and oxidation, unit: %; The SO2 content in the flue gas produced by coal combustion before SO2 is converted to SO3, in mg / m 3 ; A is a coefficient, which can be determined by data fitting. In a specific embodiment, A is 1.73662.

[0194] Furthermore, the SO3 content in the flue gas generated by the coal combustion in the target coal-fired power plant boiler is determined by the following formula:

[0195]

[0196] Where, The SO3 content in the flue gas produced by coal combustion, unit: mg / m 3 ; The SO2 content in the flue gas produced by coal combustion before SO2 is converted to SO3, in mg / m 3 ;η 燃烧 It is the conversion rate of SO2 to SO3 during the combustion and oxidation process of coal, unit is %.

[0197] Furthermore, the SO2 content in the flue gas generated by the coal combustion in the target coal-fired power plant boiler is determined by the following formula:

[0198]

[0199] Where, The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ; The SO2 content in the flue gas produced by coal combustion before SO2 is converted to SO3, in mg / m 3 ;η 燃烧 It is the conversion rate of SO2 to SO3 during the combustion and oxidation process of coal, unit is %.

[0200] Furthermore, the calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process is:

[0201]

[0202] Where η 脱硝 is the conversion rate of SO2 to SO3 during the denitration catalytic oxidation process of the air preheater corresponding to the denitration reactor, unit %; Q1 is the denitration flue gas volume of the air preheater corresponding to the denitration reactor, unit m 3 / h;T 脱硝入口 The flue gas temperature at the denitration inlet of the denitration reactor corresponding to the air preheater, in °C, can be obtained from the real-time operating data of the DCS dial; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ; S is the total geometric surface area of ​​the denitration catalyst in the denitration reactor corresponding to the air preheater, unit m 2 , which can be obtained from the performance data provided by the catalyst supplier or the test data of the power plant; f(t) is the activity coefficient of the denitration catalyst in the air preheater corresponding to the denitration reactor, which changes with the use hours. The unit is dimensionless and can be obtained from the activity coefficient change curve provided by the catalyst supplier or the activity coefficient obtained from the actual test of the power plant; C k is the content of the kth active component in the denitration catalyst of the air preheater corresponding to the denitration reactor, in %, which can be obtained from the performance data provided by the catalyst supplier or the test data of the power plant; K is the total number of active components of the denitration catalyst of the air preheater corresponding to the denitration reactor, in dimensionless units, which can be obtained from the performance data provided by the catalyst supplier or the test data of the power plant; B1, B2, B3, B4, B5, Dk is the coefficient, which can be determined by data fitting;

[0203] In a specific embodiment, B1, B2, B3, B4, and B5 are respectively -0.79943, 0.00227, -1.30068, -0.00299, and 0.80849;

[0204] In a specific embodiment, the active components of the denitration catalyst are V2O5, WO3, and MoO3, the coefficient corresponding to the content of V2O5 is 0.02062, the coefficient corresponding to the content of WO3 is 0.00627, and the coefficient corresponding to the content of MoO3 is -0.00942.

[0205] Furthermore, the SO3 generated during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant is determined by the following formula:

[0206]

[0207] Where, The SO3 content generated during the denitration catalytic oxidation process in the denitration reactor corresponding to the air preheater, in mg / m 3 ; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ;η 脱硝 It is the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater, unit: %.

[0208] Furthermore, the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant is determined by the following formula:

[0209]

[0210]

[0211] Where, The SO3 content generated during the denitration catalytic oxidation process in the denitration reactor corresponding to the air preheater, in mg / m 3 ; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ; The SO3 content in the flue gas at the denitration outlet of the air preheater corresponding to the denitration reactor, in mg / m 3 ; It is the SO3 content in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater, in ppm.

[0212] Furthermore, the first module 21 includes:

[0213] The fifth submodule 215 is configured to determine the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant based on the flue gas volume generated by the coal combustion in the boiler of the target coal-fired power plant;

[0214] Among them, the denitrification flue gas volume of the air preheater corresponding to the denitrification reactor of the target coal-fired power plant can be determined by the following formula:

[0215]

[0216] Where Q i is the denitrification flue gas volume of the denitrification reactor corresponding to the i-th air preheater, unit: m 3 / h; Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; Q0 is the amount of flue gas generated by coal combustion, unit: m 3 / h; ΔP i is the operating pressure difference between the i-th air preheater and the denitrification reactor, in Pa, which can be obtained from the unit panel DCS real-time data / h; ΔP1 is the operating pressure difference between the target air preheater and the denitrification reactor, in Pa, which can be obtained from the unit panel DCS real-time data; n is the total number of air preheaters (i.e. the total number of denitrification reactors), in Pa;

[0217] For example, when the total number of air preheaters in a coal-fired power plant (i.e., the total number of denitrification reactors) is 1, Q1 = Q0

[0218] For example, when the total number of air preheaters in a coal-fired power plant (i.e. the total number of denitrification reactors) is 2,

[0219] Furthermore, the converted overspray ammonia content at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant is determined by the following formula:

[0220]

[0221] Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; The oxygen content at the denitrification inlet, in %, can be obtained from the DCS real-time data on the unit panel. The average value can be taken when there are multiple measurement points. The NOx concentration at the denitration inlet of the air preheater corresponding to the denitration reactor, in mg / m 3 (standard state, dry basis, 6% oxygen content), which can be derived from the DCS real-time data on the unit panel, and the average value can be taken when multiple measurement points are used; The NOx concentration at the denitration outlet of the air preheater corresponding to the denitration reactor, in mg / m 3(standard state, dry basis, 6% oxygen content), which can be derived from the DCS real-time data on the unit panel, and the average value can be taken when multiple measurement points are used; The ammonia supply flow rate of the air preheater corresponding to the denitrification reactor, in kg / h, can be obtained from the DCS real-time data on the unit panel; It is the converted overspray ammonia content at the denitrification outlet of the denitrification reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2).

[0222] Furthermore, the distribution ratio of the oversprayed ammonia of the air preheater corresponding to the denitrification reactor of the target coal-fired power plant in the denitrification outlet flue gas is determined by the following formula:

[0223]

[0224] Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; The ammonium ion content in the fly ash at the denitrification outlet of the denitrification reactor corresponding to the air preheater, in mg / kg; is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); m is the coal consumption, in t / h, which can be obtained from the real-time DCS data of the unit panel; A ar is the basic ash content of the coal, unit is %; K 脱硝烟气 It is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless.

[0225] Furthermore, the calculation model for the generation rate of ammonium bisulfate is:

[0226]

[0227] Where, K is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; 空预器出口 is the flue gas temperature at the air preheater outlet, in °C, which can be obtained from the DCS real-time data of the unit panel. The average value can be taken when there are multiple measurement points. ABS is the generation rate of ammonium bisulfate, and the unit is dimensionless; E1, E2, E3, and E4 are coefficients that can be determined by data fitting;

[0228] In a specific embodiment, E1, E2, E3, and E4 are 89.7985, -0.353, 5.233, and 9.491, respectively.

[0229] Furthermore, the amount of ammonium bisulfate generated in the air preheater of the target coal-fired power plant is determined by the following formula:

[0230]

[0231] Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; K is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; P is the SO3 content in the denitrification outlet flue gas of the air preheater corresponding to the denitrification reactor, unit: ppm; ABS is the generation rate of ammonium bisulfate, unit is dimensionless; m ABS It is the amount of ammonium bisulfate produced, in kg / h.

[0232] An embodiment of the present invention provides a system for determining the risk of ammonium bisulfate deposition in an air preheater of a coal-fired power plant. The system can implement the above-mentioned method for determining the risk of ammonium bisulfate deposition in an air preheater of a coal-fired power plant. The system includes:

[0233] The system for determining the output of ammonium bisulfate in a coal-fired power plant provided in the above embodiment (for details, please refer to the above embodiment of the system for determining the output of ammonium bisulfate in a coal-fired power plant, which will not be described in detail again), and

[0234] Fifth Module 25: A calculation model for obtaining the initial formation temperature of ammonium bisulfate, which is a calculation model for the initial formation temperature of ammonium bisulfate with respect to the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the SO3 content in the flue gas at the denitrification outlet; based on the calculation model for the initial formation temperature of ammonium bisulfate, combined with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, the initial formation temperature of ammonium bisulfate in the air preheater of the target coal-fired power plant is determined;

[0235] Module 6 26: A calculation model for the risk value of ammonium bisulfate deposition in the air preheater, which is a calculation model for the risk value of ammonium bisulfate deposition in the air preheater with respect to the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, the SO3 content in the flue gas at the denitrification outlet, the initial formation temperature of ammonium bisulfate, the flue gas temperature at the air preheater outlet, and the metal wall temperature at the cold end of the air preheater; based on the calculation model for the risk of ammonium bisulfate deposition in the air preheater, combined with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the initial formation temperature of ammonium bisulfate in the air preheater, the risk value of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant is determined.

[0236] Furthermore, the calculation model for the initial formation temperature of ammonium bisulfate is:

[0237]

[0238] Where, K is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; IFT is the initial formation temperature of ammonium bisulfate, in °C; F1, F2, and F3 are coefficients that can be determined by data fitting;

[0239] In a specific embodiment, F1, F2, and F3 are 194.157, 11.479, and 0.221, respectively.

[0240] Furthermore, the risk value calculation model for ammonium bisulfate deposition in the air preheater is:

[0241]

[0242] Where, K is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; IFT is the initial formation temperature of ammonium bisulfate, unit is °C; T 空预器冷端 T is the metal wall temperature at the cold end of the air preheater, in °C; 空预器出口 is the flue gas temperature at the air preheater outlet, unit: °C; P bis the risk value of ammonium bisulfate deposition in the air preheater, in %; G1 and G2 are coefficients, which can be determined by data fitting;

[0243] In a specific embodiment, G1 and G2 are 0.221 and -1.254 respectively.

[0244] Furthermore, the system further comprises:

[0245] Module 7 27: used to conduct risk assessment of ammonium bisulfate deposition in the air preheater of a target coal-fired power plant based on the risk value of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant;

[0246] Furthermore, the seventh module 27 is used to:

[0247] When the risk value of ammonium bisulfate deposition in the air preheater is less than 60%, it is considered that the amount of ammonium bisulfate generated in the air preheater has no deposition risk to the air preheater, that is, it will not significantly cause blockage of the air preheater and increase in pressure difference;

[0248] When the risk value of ammonium bisulfate deposition in the air preheater is 60%-80%, it is considered that the amount of ammonium bisulfate generated in the air preheater poses a deposition risk to the air preheater. The larger the value, the greater the deposition risk. The soot blowing frequency of the air preheater should be appropriately increased to avoid continuous deposition and clogging of the air preheater by ammonium bisulfate.

[0249] When the risk value of ammonium bisulfate deposition in the air preheater is greater than 80%, it is considered that the amount of ammonium bisulfate generated in the air preheater poses a significant deposition risk to the air preheater. The larger the value, the greater the deposition risk. While increasing the injection frequency of the air preheater and ensuring that the NOx emission concentration does not exceed the standard, the amount of ammonia sprayed for denitrification should be reduced in a timely manner, or an optimization adjustment test of ammonia spraying for denitrification should be carried out to reduce ineffective overspray of ammonia.

[0250] Example 1

[0251] This example uses a 660MW coal-fired power plant boiler unit as an example. The unit's denitration system includes a denitration reactor and an air preheater. The SO3 content in the unit's denitration outlet flue gas, the amount of oversprayed ammonia and its distribution in the denitration outlet flue gas, the ammonium bisulfate production, and the risk of ammonium bisulfate deposition in the air preheater are shown in Tables 1, 2, and 3, respectively. Specifically, this example determines the ammonium bisulfate production and the risk of ammonium bisulfate deposition in the air preheater using the following methods:

[0252] 1. Obtain the SO3 content and denitrification flue gas volume in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant; specifically including:

[0253] 1.1. Obtain the coal quality data and real-time operating parameters of the target coal-fired power plant boiler; then determine the standard dry flue gas volume generated by the target coal-fired power plant boiler as the flue gas volume generated by the target coal-fired power plant boiler, and determine the SO2 content in the standard dry flue gas generated by the target coal-fired power plant boiler before SO2 to SO3 conversion occurs as the SO2 content in the flue gas generated by the target coal-fired power plant boiler before SO2 to SO3 conversion occurs using the following formula:

[0254] in,

[0255]

[0256] V0=0.0889×(C ar +0.375×S ar )+0.265×H ar -0.0333×O ar

[0257]

[0258] Where C ar is the carbon content of the coal as received, in %; H ar The unit of hydrogen received from coal combustion is %; N ar is the basic nitrogen received from coal combustion, unit: %; S ar The total sulfur content of the coal as received, in %, can be obtained from the daily coal quality test of the power plant; ar is the basic oxygen received by coal combustion, unit is %; m is the amount of coal combustion, unit is t / h; V0 is the theoretical air volume, unit is m 3 / kg; is the standard dry flue gas volume coefficient, unit: m 3 / kg; Q0 is the standard dry flue gas volume generated by coal combustion (i.e. the flue gas volume generated by coal combustion), unit: m 3 / h (standard state, dry basis, 6% oxygen content); is the oxygen content at the denitrification inlet, unit: %; It is the SO2 content in the standard dry flue gas produced by coal combustion before SO2 is converted to SO3 (i.e. the SO2 content in the flue gas produced by coal combustion), in mg / m 3 (Standard state, dry basis, 6% oxygen content).

[0259] 1.2. Determine the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant using the following formula:

[0260] Q1=Q0

[0261] Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m3 / h; Q0 is the amount of flue gas generated by coal combustion, unit: m 3 / h;

[0262] 1.3. Obtain a calculation model for the conversion rate of SO2 to SO3 during the combustion and oxidation process of coal, and determine the conversion rate of SO2 to SO3 during the combustion and oxidation process of coal in the target coal-fired power plant boiler:

[0263]

[0264] Where η 燃烧 is the conversion rate of SO2 to SO3 during coal combustion and oxidation, unit: %; The SO2 content in the flue gas produced by coal combustion before SO2 is converted to SO3, in mg / m 3 ;

[0265] Then, the SO3 content in the flue gas generated by the coal combustion in the target coal-fired power plant boiler and the SO2 content in the flue gas generated by the coal combustion in the target coal-fired power plant boiler are determined by the following formula:

[0266]

[0267]

[0268] Where, The SO3 content in the flue gas produced by coal combustion, unit: mg / m 3 ; The SO2 content in the flue gas produced by coal combustion before SO2 is converted to SO3, in mg / m 3 ;η 燃烧 is the conversion rate of SO2 to SO3 during coal combustion and oxidation, unit: %; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 .

[0269] 1.4. Obtain a calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process, and determine the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant:

[0270]

[0271] Where η 脱硝 is the conversion rate of SO2 to SO3 during the denitration catalytic oxidation process of the air preheater corresponding to the denitration reactor, unit %; Q1 is the denitration flue gas volume of the air preheater corresponding to the denitration reactor, unit m 3 / h;T 脱硝入口 The flue gas temperature at the denitration inlet of the denitration reactor corresponding to the air preheater, unit: °C; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ; S is the total geometric surface area of ​​the denitration catalyst in the denitration reactor corresponding to the air preheater, unit m 2 ; f(t) is the activity coefficient of the denitration catalyst in the air preheater corresponding to the denitration reactor, which changes with the use hours, and the unit is dimensionless; C k is the content of the kth active component in the denitration catalyst of the denitration reactor corresponding to the air preheater, in %; K is the total number of active components of the denitration catalyst of the denitration reactor corresponding to the air preheater, in dimensionless units; is the content of V2O5 active component in the denitration catalyst, unit: %; is the content of MoO3 active component in the denitration catalyst, unit: %; is the content of WO3 active component in the denitration catalyst, unit: %;

[0272] Then, the SO3 content generated during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant is determined by the following formula:

[0273]

[0274] Where, The SO3 content generated during the denitration catalytic oxidation process in the denitration reactor corresponding to the air preheater, in mg / m 3 ; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ;η 脱硝 It is the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater, unit: %.

[0275] 1.5. Determine the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant using the following formula:

[0276]

[0277]

[0278] Where, The SO3 content generated during the denitration catalytic oxidation process in the denitration reactor corresponding to the air preheater, in mg / m 3 ; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ; The SO3 content in the flue gas at the denitration outlet of the air preheater corresponding to the denitration reactor, in mg / m 3 ; It is the SO3 content in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater, in ppm.

[0279] 2. Determine the converted overspray ammonia content at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant and the distribution ratio of the overspray ammonia in the flue gas at the denitrification outlet using the following formula:

[0280]

[0281]

[0282] Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; is the oxygen content at the denitrification inlet, unit: %; The NOx concentration at the denitration inlet of the air preheater corresponding to the denitration reactor, in mg / m 3 (standard state, dry basis, 6% oxygen content); The NOx concentration at the denitration outlet of the air preheater corresponding to the denitration reactor, in mg / m 3 (standard state, dry basis, 6% oxygen content); is the ammonia supply flow rate of the air preheater corresponding to the denitrification reactor, unit: kg / h; The converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); is the ammonium ion content in the denitrification outlet fly ash of the denitrification reactor corresponding to the air preheater, in mg / kg; m is the coal consumption, in t / h; A ar is the basic ash content of the coal, unit is %; K 脱硝烟气 It is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless.

[0283] 3. Obtain the calculation model for the generation rate of ammonium bisulfate and determine the generation rate of ammonium bisulfate in the air preheater of the target coal-fired power plant:

[0284]

[0285] Where, K is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; 空预器出口 is the flue gas temperature at the air preheater outlet, unit: °C; P ABS is the generation rate of ammonium bisulfate, and the unit is dimensionless.

[0286] 4. Determine the amount of ammonium bisulfate generated in the air preheater of the target coal-fired power plant using the following formula:

[0287]

[0288] Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; K is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; P is the SO3 content in the denitrification outlet flue gas of the air preheater corresponding to the denitrification reactor, unit: ppm; ABS is the generation rate of ammonium bisulfate, unit is dimensionless; m ABS It is the amount of ammonium bisulfate produced, in kg / h.

[0289] 5. Obtain the calculation model of the initial formation temperature of ammonium bisulfate and determine the initial formation temperature of ammonium bisulfate in the air preheater of the target coal-fired power plant:

[0290]

[0291] Where, K is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; IFT is the initial formation temperature of ammonium bisulfate, unit is ℃.

[0292] 6. Obtain the calculation model for the risk value of ammonium bisulfate deposition in the air preheater and determine the risk value of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant:

[0293]

[0294] Where, K is the converted overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater, in ppm (standard state, dry basis, 6% O2); 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; IFT is the initial formation temperature of ammonium bisulfate, unit is °C; T 空预器冷端 T is the metal wall temperature at the cold end of the air preheater, in °C; 空预器出口is the flue gas temperature at the air preheater outlet, unit: °C; P b It is the risk value of ammonium bisulfate deposition in the air preheater, unit: %.

[0295] 7. Based on the risk value of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant, conduct a risk assessment of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant;

[0296] When the risk value of ammonium bisulfate deposition in the air preheater is less than 60%, it is considered that the amount of ammonium bisulfate generated in the air preheater has no deposition risk to the air preheater, that is, it will not significantly cause blockage of the air preheater and increase in pressure difference;

[0297] When the risk value of ammonium bisulfate deposition in the air preheater is 60%-80%, it is considered that the amount of ammonium bisulfate generated in the air preheater poses a deposition risk to the air preheater. The larger the value, the greater the deposition risk. The soot blowing frequency of the air preheater should be appropriately increased to avoid continuous deposition and clogging of the air preheater by ammonium bisulfate.

[0298] When the risk value of ammonium bisulfate deposition in the air preheater is greater than 80%, it is considered that the amount of ammonium bisulfate generated in the air preheater poses a significant deposition risk to the air preheater. The larger the value, the greater the deposition risk. While increasing the injection frequency of the air preheater and ensuring that the NOx emission concentration does not exceed the standard, the amount of ammonia sprayed for denitrification should be reduced in a timely manner, or an optimization adjustment test of ammonia spraying for denitrification should be carried out to reduce ineffective overspray of ammonia.

[0299] Table 1

[0300]

[0301] Table 2

[0302]

[0303] Table 3

[0304] project Data Source unit Numerical <![CDATA[Cold-end metal wall temperature T of the air preheater 空预器冷端 > Dial DCS real-time data (average value) ℃ 142.2 <![CDATA[Flue gas temperature T at the outlet of the air preheater 空预器出口 > Dial DCS real-time data (average value) ℃ 143.4 <![CDATA[Production rate P of ammonium bisulfate ABS > Calculated value / 0.68 <![CDATA[The production amount m of ammonium bisulfate ABS > Calculated value kg / h 38.64 <![CDATA[Initial formation temperature T of ammonium bisulfate IFT > Calculated value ℃ 213.53 <![CDATA[Risk value P of ammonium bisulfate deposition in air preheater b > Calculated value ％ 52.04

[0305] The above describes preferred embodiments of the present invention. Many features and advantages of these embodiments are apparent from this detailed description, and thus the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, the embodiments of the present invention are not intended to be limited to the exact construction and operation illustrated and described, but are intended to cover all suitable modifications and equivalents that fall within the scope thereof.

Claims

1. A method for determining the output of ammonium bisulfate in a coal-fired power plant, wherein: The method includes: Obtain the SO3 content and denitrification flue gas volume in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant; Combined with the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, determine the converted overspray ammonia content at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant and the distribution ratio of the overspray ammonia in the denitrification outlet flue gas; Obtain a calculation model for the generation rate of ammonium bisulfate, which is a calculation model for the generation rate of ammonium bisulfate with respect to the flue gas temperature at the air preheater outlet, the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the SO3 content in the flue gas at the denitrification outlet; determine the generation rate of ammonium bisulfate in the air preheater of the target coal-fired power plant based on the calculation model for the generation rate of ammonium bisulfate, in combination with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet; Based on the generation rate of ammonium bisulfate in the air preheater of the target coal-fired power plant, combined with the denitrification flue gas volume of the corresponding denitrification reactor of the air preheater of the target coal-fired power plant, the SO3 content in the flue gas at the denitrification outlet, the converted overspray ammonia content at the denitrification outlet and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, the generation amount of ammonium bisulfate in the air preheater of the target coal-fired power plant is determined.

2. The method according to claim 1, wherein Obtaining the SO3 content in the flue gas from the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant includes: Obtaining the amount of flue gas generated by coal combustion in the target coal-fired power plant boiler and the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler before SO2 is converted to SO3; Obtain a calculation model for the conversion rate of SO2 to SO3 during coal-fired combustion and oxidation, which is a calculation model for the conversion rate of SO2 to SO3 during coal-fired combustion and oxidation with respect to the SO2 content; determine the conversion rate of SO2 to SO3 during coal-fired combustion and oxidation in the target coal-fired power plant boiler based on the calculation model for the conversion rate of SO2 to SO3 during coal-fired combustion and oxidation, combined with the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler before the SO2 to SO3 conversion occurs; determine the SO3 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler and the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler based on the conversion rate of SO2 to SO3 during coal-fired combustion and oxidation in the target coal-fired power plant boiler, combined with the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler before the SO2 to SO3 conversion occurs; Obtain a calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process, which is a calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process with respect to the denitrification inlet flue gas temperature, denitrification catalyst composition parameters, denitrification catalyst activity coefficient, SO2 content in the flue gas generated by coal combustion, denitrification flue gas volume and total geometric surface area of ​​the denitrification catalyst; based on the calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process, combined with the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler and the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, determine the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant; based on the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, combined with the SO2 content in the flue gas generated by coal combustion in the target coal-fired power plant boiler, determine the SO3 content generated during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant; Based on the SO3 content in the flue gas generated by coal combustion in the boiler of the target coal-fired power plant and the SO3 content generated during the denitrification catalytic oxidation process of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the SO3 content in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant is determined.

3. The method according to claim 2, wherein: The calculation model of the conversion rate of SO2 to SO3 in the process of coal combustion oxidation with respect to SO2 content is: Where η 燃烧 is the conversion rate of SO2 to SO3 during coal combustion and oxidation, unit: %; The SO2 content in the flue gas produced by coal combustion before SO2 is converted to SO3, in mg / m 3 ; A is the coefficient.

4. The method according to claim 2, wherein: The calculation model for the conversion rate of SO2 to SO3 during the denitrification catalytic oxidation process is: Where η 脱硝 is the conversion rate of SO2 to SO3 during the denitration catalytic oxidation process of the air preheater corresponding to the denitration reactor, unit %; Q1 is the denitration flue gas volume of the air preheater corresponding to the denitration reactor, unit m 3 / h;T 脱硝入口 The flue gas temperature at the denitration inlet of the denitration reactor corresponding to the air preheater, unit: °C; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 ; S is the total geometric surface area of ​​the denitration catalyst in the denitration reactor corresponding to the air preheater, unit m 2 ; f(t) is the activity coefficient of the denitration catalyst in the air preheater corresponding to the denitration reactor, which changes with the use hours, and the unit is dimensionless; C k is the content of the kth active component in the denitration catalyst of the air preheater corresponding to the denitration reactor, unit %; K is the total number of active components of the denitration catalyst of the air preheater corresponding to the denitration reactor, unit dimensionless; B1, B2, B3, B4, B5, D k is the coefficient.

5. The method according to claim 1, wherein The SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor of the target coal-fired power plant is determined by the following formula: Where, The SO3 content generated during the denitration catalytic oxidation process in the denitration reactor corresponding to the air preheater, in mg / m 3 ; The SO2 content in the flue gas produced by coal combustion, unit: mg / m 3 m denitrification outlet SO3 is the SO3 content in the denitrification outlet flue gas of the air preheater corresponding denitrification reactor, unit: mg / m 3 ; C denitrification outlet SO3 is the SO3 content in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater, unit: ppm.

6. The method according to claim 1, wherein The denitrification flue gas volume of the air preheater corresponding to the denitrification reactor of the target coal-fired power plant is obtained by the following method: Based on the flue gas volume generated by coal combustion in the boiler of the target coal-fired power plant, the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant is determined.

7. The method according to claim 6, wherein: The denitrification flue gas volume of the target coal-fired power plant air preheater corresponding to the denitrification reactor is determined by the following formula: Where Q i is the denitrification flue gas volume of the denitrification reactor corresponding to the i-th air preheater, unit: m 3 / h; Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; Q0 is the amount of flue gas generated by coal combustion, unit: m 3 / h; ΔP i is the operating pressure difference between the i-th air preheater and the denitrification reactor, in Pa; ΔP1 is the operating pressure difference between the target air preheater and the denitrification reactor, in Pa; n is the total number of air preheaters, in Pa.

8. The method according to claim 1, wherein The converted overspray ammonia content at the denitrification outlet of the air preheater corresponding to the denitrification reactor of the target coal-fired power plant is determined by the following formula: Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; is the oxygen content at the denitrification inlet, unit: %; The NOx concentration at the denitration inlet of the air preheater corresponding to the denitration reactor, in mg / m 3 ; The NOx concentration at the denitration outlet of the air preheater corresponding to the denitration reactor, in mg / m 3 ; is the ammonia supply flow rate of the air preheater corresponding to the denitrification reactor, unit: kg / h; It is the converted overspray ammonia content at the denitrification outlet of the denitrification reactor corresponding to the air preheater, in ppm.

9. The method according to claim 1, wherein The distribution ratio of the oversprayed ammonia in the denitrification outlet flue gas of the air preheater corresponding to the denitrification reactor of the target coal-fired power plant is determined by the following formula: Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; The ammonium ion content in the fly ash at the denitrification outlet of the denitrification reactor corresponding to the air preheater, in mg / kg; is the converted overspray ammonia content at the denitration outlet of the air preheater corresponding to the denitration reactor, in ppm; m is the coal consumption, in t / h; A ar is the basic ash content of the coal, unit is %; K 脱硝烟气 It is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless.

10. The method according to claim 1, wherein The calculation model for the generation rate of ammonium bisulfate is: Where, K is the converted overspray ammonia content at the denitration outlet of the air preheater corresponding to the denitration reactor, in ppm; 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; 空预器出口 is the flue gas temperature at the air preheater outlet, unit: °C; P ABS is the generation rate of ammonium bisulfate, the unit is dimensionless; E1, E2, E3, E4 are coefficients.

11. The method according to claim 1, wherein The amount of ammonium bisulfate generated in the air preheater of the target coal-fired power plant is determined by the following formula: Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; K is the converted overspray ammonia content at the denitration outlet of the air preheater corresponding to the denitration reactor, in ppm; 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; P is the SO3 content in the denitrification outlet flue gas of the air preheater corresponding to the denitrification reactor, unit: ppm; ABS is the generation rate of ammonium bisulfate, unit is dimensionless; m ABS It is the amount of ammonium bisulfate produced, in kg / h.

12. A method for determining the risk of ammonium bisulfate deposition in an air preheater of a coal-fired power plant, wherein: The method includes: Determining the amount of ammonium bisulfate generated in the air preheater of a target coal-fired power plant using the method for determining the ammonium bisulfate output of a coal-fired power plant according to any one of claims 1 to 11; Obtaining a calculation model for the initial formation temperature of ammonium bisulfate, which is a calculation model for the initial formation temperature of ammonium bisulfate with respect to the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the SO3 content in the flue gas at the denitrification outlet; determining the initial formation temperature of ammonium bisulfate in the air preheater of the target coal-fired power plant based on the calculation model for the initial formation temperature of ammonium bisulfate in combination with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet; A calculation model for the risk value of ammonium bisulfate deposition in the air preheater is obtained, which is a calculation model for the risk value of ammonium bisulfate deposition in the air preheater with respect to the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, the SO3 content in the flue gas at the denitrification outlet, the initial formation temperature of ammonium bisulfate, the flue gas temperature at the air preheater outlet, and the metal wall temperature at the cold end of the air preheater. Based on the calculation model for the risk of ammonium bisulfate deposition in the air preheater, combined with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the initial formation temperature of ammonium bisulfate in the air preheater, the risk value of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant is determined.

13. The method according to claim 12, wherein: The calculation model for the initial formation temperature of ammonium bisulfate is: Where, K is the converted overspray ammonia content at the denitration outlet of the air preheater corresponding to the denitration reactor, in ppm; 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; IFT is the initial formation temperature of ammonium bisulfate, unit is °C; F1, F2, F3 are coefficients.

14. The method according to claim 12, wherein: The calculation model for the risk value of ammonium bisulfate deposition in the air preheater is: Where, K is the converted overspray ammonia content at the denitration outlet of the air preheater corresponding to the denitration reactor, in ppm; 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; IFT is the initial formation temperature of ammonium bisulfate, unit is °C; T 空预器冷端 T is the metal wall temperature at the cold end of the air preheater, in °C; 空预器出口 is the flue gas temperature at the air preheater outlet, unit: °C; P b is the risk value of ammonium bisulfate deposition in the air preheater, unit: %; G1 and G2 are coefficients.

15. The method according to claim 14, wherein The method further comprises: Based on the risk value of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant, the risk assessment of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant is carried out; When the risk value of ammonium bisulfate deposition in the air preheater is less than 60%, the amount of ammonium bisulfate generated in the air preheater poses no deposition risk to the air preheater; When the risk value of ammonium bisulfate deposition in the air preheater is 60%-80%, the amount of ammonium bisulfate generated in the air preheater poses a deposition risk to the air preheater; When the risk value of ammonium bisulfate deposition in the air preheater is greater than 80%, the amount of ammonium bisulfate generated in the air preheater poses a significant deposition risk to the air preheater.

16. A system for determining the production of ammonium bisulfate in a coal-fired power plant, wherein: The system includes: The first module is used to obtain the SO3 content and denitrification flue gas volume in the denitrification outlet flue gas of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant; The second module is used to determine the overspray ammonia content at the denitration outlet of the denitration reactor corresponding to the air preheater of the target coal-fired power plant and the distribution ratio of the overspray ammonia in the flue gas at the denitration outlet, based on the denitration flue gas volume of the denitration reactor corresponding to the air preheater of the target coal-fired power plant; The third module is used to obtain a calculation model for the generation rate of ammonium bisulfate, which is a calculation model for the generation rate of ammonium bisulfate with respect to the flue gas temperature at the air preheater outlet, the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the SO3 content in the flue gas at the denitrification outlet. The generation rate of ammonium bisulfate in the air preheater of the target coal-fired power plant is determined based on the calculation model for the generation rate of ammonium bisulfate, in combination with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet. The fourth module is used to determine the generation amount of ammonium bisulfate in the air preheater of the target coal-fired power plant based on the generation rate of ammonium bisulfate in the air preheater of the target coal-fired power plant, the denitrification flue gas volume of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the SO3 content in the flue gas at the denitrification outlet, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet.

17. The system according to claim 16, wherein: The distribution ratio of the oversprayed ammonia in the denitrification outlet flue gas of the air preheater corresponding to the denitrification reactor of the target coal-fired power plant is determined by the following formula: Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; The ammonium ion content in the fly ash at the denitrification outlet of the denitrification reactor corresponding to the air preheater, in mg / kg; is the converted overspray ammonia content at the denitration outlet of the air preheater corresponding to the denitration reactor, in ppm; m is the coal consumption, in t / h; A ar is the basic ash content of the coal, unit is %; K 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; The calculation model for the generation rate of ammonium bisulfate is: Where, K is the converted overspray ammonia content at the denitration outlet of the air preheater corresponding to the denitration reactor, in ppm; 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; 空预器出口 is the flue gas temperature at the air preheater outlet, unit: °C; P ABS is the generation rate of ammonium bisulfate, unit is dimensionless; E1, E2, E3, E4, are coefficients; The amount of ammonium bisulfate generated in the air preheater of the target coal-fired power plant is determined by the following formula: Where Q1 is the denitrification flue gas volume of the target air preheater corresponding to the denitrification reactor, unit: m 3 / h; K is the converted overspray ammonia content at the denitration outlet of the air preheater corresponding to the denitration reactor, in ppm; 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; P is the SO3 content in the denitrification outlet flue gas of the air preheater corresponding to the denitrification reactor, unit: ppm; ABS is the generation rate of ammonium bisulfate, unit is dimensionless; m ABS It is the amount of ammonium bisulfate produced, in kg / h.

18. A system for determining the risk of ammonium bisulfate deposition in an air preheater of a coal-fired power plant, wherein: The system includes: The system for determining the ammonium bisulfate output of a coal-fired power plant according to claim 16 or 17, and Module 5: A calculation model for obtaining the initial formation temperature of ammonium bisulfate, which is a calculation model for the initial formation temperature of ammonium bisulfate with respect to the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, and the SO3 content in the flue gas at the denitrification outlet; based on the calculation model for the initial formation temperature of ammonium bisulfate, combined with the SO3 content in the flue gas at the denitrification outlet of the denitrification reactor corresponding to the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, and the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, the initial formation temperature of ammonium bisulfate in the air preheater of the target coal-fired power plant is determined; Module 6: used to obtain the calculation model of the risk value of ammonium bisulfate deposition in the air preheater. The model is a calculation model for the risk value of ammonium bisulfate deposition in the air preheater regarding the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet, the SO3 content in the flue gas at the denitrification outlet, the initial formation temperature of ammonium bisulfate, the flue gas temperature at the air preheater outlet and the metal wall temperature at the cold end of the air preheater. Based on the calculation model of the risk of ammonium bisulfate deposition in the air preheater, combined with the SO3 content in the flue gas at the denitrification outlet of the corresponding denitrification reactor of the air preheater of the target coal-fired power plant, the converted overspray ammonia content at the denitrification outlet, the distribution ratio of overspray ammonia in the flue gas at the denitrification outlet and the initial formation temperature of ammonium bisulfate in the air preheater, the risk value of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant is determined.

19. The system according to claim 18, wherein: The calculation model for the initial formation temperature of ammonium bisulfate is: Where, K is the converted overspray ammonia content at the denitration outlet of the air preheater corresponding to the denitration reactor, in ppm; 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; IFT is the initial formation temperature of ammonium bisulfate, unit is °C; F1, F2, F3 are coefficients; The calculation model for the risk value of ammonium bisulfate deposition in the air preheater is: Where, K is the converted overspray ammonia content at the denitration outlet of the air preheater corresponding to the denitration reactor, in ppm; 脱硝烟气 is the distribution ratio of oversprayed ammonia in the flue gas at the denitrification outlet, and the unit is dimensionless; T is the SO3 content in the flue gas at the denitrification outlet of the air preheater corresponding to the denitrification reactor, in ppm; IFT is the initial formation temperature of ammonium bisulfate, unit is °C; T 空预器冷端 T is the metal wall temperature at the cold end of the air preheater, in °C; 空预器出口 is the flue gas temperature at the air preheater outlet, unit: °C; P b is the risk value of ammonium bisulfate deposition in the air preheater, unit: %; G1 and G2 are coefficients.

20. The system of claim 19, wherein: The system further comprises: The seventh module is used to evaluate the risk of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant based on the risk value of ammonium bisulfate deposition in the air preheater of the target coal-fired power plant; When the risk value of ammonium bisulfate deposition in the air preheater is less than 60%, the amount of ammonium bisulfate generated in the air preheater poses no deposition risk to the air preheater; When the risk value of ammonium bisulfate deposition in the air preheater is 60%-80%, the amount of ammonium bisulfate generated in the air preheater poses a deposition risk to the air preheater; When the risk value of ammonium bisulfate deposition in the air preheater is greater than 80%, the amount of ammonium bisulfate generated in the air preheater poses a significant deposition risk to the air preheater.

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