CN105032154A

CN105032154A - Ammonia desulphurization absorbent product S<4+> oxidation system and optimal regulation and control method

Info

Publication number: CN105032154A
Application number: CN201510464978.8A
Authority: CN
Inventors: 贾勇; 陈�光; 戴波; 吴胜华; 盛广宏
Original assignee: Anhui University of Technology AHUT
Current assignee: Anhui University of Technology AHUT
Priority date: 2015-07-29
Filing date: 2015-07-29
Publication date: 2015-11-11
Anticipated expiration: 2035-07-29
Also published as: CN105032154B

Abstract

The invention discloses an ammonia method desulfurization absorption product + tetravalent sulfur oxidation system and an optimization control method thereof, belonging to the technical field of air pollution control. In the present invention, at first the model parameters in the ammonia desulfurization system are determined; input the above model parameters, and set an initial pH value, oxidizing air quantity Q and S ⁴⁺ and S ⁶⁺ initial concentrations , using the oxidation rate model of +4-valent sulfur to calculate the oxidation rate of +4-valent sulfur in the slurry pool ; The calculated +4-valent sulfur oxidation rate bring in test, and if not, adjust and The value of is recalculated until established, and compare the obtained oxidation rate with the set value in the project, and adjust the pH value in the model, the amount of oxidizing air Q, and The value of , so that the oxidation rate of +4 valent sulfur can meet the engineering requirements. The oxidation rate model in the invention can provide theoretical guidance for the design and operation of the ammonia desulfurization absorption product+quaternary sulfur oxidation system, thereby improving the stability and economy of the ammonia desulfurization technology.

Description

Ammonia desulfurization absorption product + 4-valent sulfur oxidation system and its optimization control method

技术领域technical field

本发明属于大气污染治理技术领域，更具体地说，涉及一种氨法脱硫吸收产物+4价硫氧化系统及其优化调控方法。The invention belongs to the technical field of air pollution control, and more specifically relates to an ammonia method desulfurization absorption product + tetravalent sulfur oxidation system and an optimization control method thereof.

背景技术Background technique

二氧化硫(SO₂)是目前在我国危害仅次于颗粒物的主要大气污染物，但它同时也是一种资源。随着国家新标准的出台，二氧化硫排放指标是400mg/Nm³，这对于很多老的使用燃煤锅炉厂家来说选择一种经济的，处理效果好的尾气处理工艺，是生产厂家最紧迫的任务。Sulfur dioxide (SO ₂ ) is the main air pollutant second only to particulate matter in China, but it is also a resource. With the promulgation of the new national standard, the sulfur dioxide emission index is 400mg/Nm ³ , which is the most urgent task for many old coal-fired boiler manufacturers to choose an economical and effective tail gas treatment process. .

目前主导的石灰石-石膏法脱硫工艺，由于脱硫装置投资较大，中小热电厂难于承受，且运行成本较高，脱硫副产物石膏采用抛弃法或填埋法处理，容易造成二次污染，同时脱硫过程中产生的大量二氧化碳是一种温室气体，从而限制了该法的应用。与钙法脱硫工艺相比，氨法脱硫是以化学反应活性较高的氨(NH₃)为脱硫剂吸收烟气中的SO₂，系统动力消耗低，在高效脱除SO₂的同时，还能实现硫资源的回收，且无废水和废渣的排放，符合我国发展循环经济、创建节约型社会的政策需求，因此其成为解决SO₂直接排放造成大气严重污染的有效途径，且氨法脱硫在我国大中型燃煤烟气脱硫项目上逐步得到了广泛应用，发展前景良好。但氨法脱硫的副产品是(NH₄)₂SO₃和NH₄HSO₃，在空气中受热容易分解，直接利用价值不大，需进一步氧化成硫酸铵进行回收利用。氨法脱硫喷淋塔是氨法脱硫系统的核心，现有技术中通常采用直接向喷淋塔内通入空气，以使(NH₄)₂SO₃和NH₄HSO₃能够氧化为稳定的+6价硫(NH₄)₂SO₄，在对+4价硫(NH₄)₂SO₃和NH₄HSO₃进行氧化处理时，涉及的主要反应如下：The current dominant limestone-gypsum desulfurization process, due to the large investment in desulfurization equipment, is difficult for small and medium-sized thermal power plants to bear, and the operating cost is high. The large amount of carbon dioxide produced in the environment is a greenhouse gas, which limits the application of this method. Compared with the calcium desulfurization process, the ammonia desulfurization process uses ammonia (NH ₃ ) with high chemical reactivity as a desulfurizer to absorb SO ₂ in the flue gas. The power consumption of the system is low. While removing SO ₂ efficiently, it also It can realize the recovery of sulfur resources without the discharge of waste water and waste residue, which is in line with the policy needs of China's development of circular economy and creation of a conservation _- minded society. Therefore, it has become an effective way to solve the serious air pollution caused by direct SO2 emissions, and ammonia desulfurization is It has gradually been widely used in large and medium-sized coal-fired flue gas desulfurization projects in China, and has a good development prospect. However, the by-products of ammonia desulfurization are (NH ₄ ) ₂ SO ₃ and NH ₄ HSO ₃ , which are easily decomposed when heated in the air, and have little value for direct use. They need to be further oxidized into ammonium sulfate for recycling. The ammonia desulfurization spray tower is the core of the ammonia desulfurization system. In the prior art, the air is usually directly fed into the spray tower so that (NH ₄ ) ₂ SO ₃ and NH ₄ HSO ₃ can be oxidized into stable + When hexavalent sulfur (NH ₄ ) ₂ SO ₄ is oxidized to +quaternary sulfur (NH ₄ ) ₂ SO ₃ and NH ₄ HSO ₃ , the main reactions involved are as follows:

因此，如何高效、低能耗地将+4价硫氧化成为+6价硫是实现氨法脱硫稳定、经济运行的基础，从而吸引了众多研究者和工程技术人员的关注。Therefore, how to oxidize +4-valent sulfur to +6-valent sulfur efficiently and with low energy consumption is the basis for realizing stable and economical operation of ammonia desulfurization, which has attracted the attention of many researchers and engineers.

氨法脱硫吸收产物+4价硫的氧化主要受浆液pH值、+4价硫浓度、+6价硫浓度、氧化空气量和温度等诸多条件的影响。迄今为止，对氨法脱硫吸收产物+4价硫氧化的研究主要集中在亚硫酸铵氧化动力学方面，比较典型的主要有：ZhouJH等(ChemicalEngineeringScience，2000，55(23):5637-5641)向搅拌反应器中溶液的上方通入一定浓度的O₂，O₂扩散进入溶液与亚硫酸铵发生氧化反应，研究结果表明亚硫酸铵的氧化速率对氧浓度呈1级，在亚硫酸根浓度低于临界浓度时对其呈-1级，在亚硫酸根浓度高于临界浓度时对其呈0.2级。ZhaoB等(ChemicalEngineeringScience，2005，60(3):863-868)建立单气泡反应装置对亚硫酸铵的氧化过程进行了实验研究，结果显示，亚硫酸铵的氧化速率在亚硫酸根浓度低于临界浓度时对其呈1级，在亚硫酸根浓度高于临界浓度时对其呈0级，亚硫酸铵的氧化速率随溶液pH值的增加而增大，当pH值在6～9时，pH值对氧化速率的影响呈线性规律。尽管学者们在亚硫酸铵氧化研究方面取得了一些有益的结果，但由于和的氧化速率不能分别单独测得，以往的研究中未对氨法脱硫吸收产物+4价硫中占多数的的氧化进行区分，且实验中pH值的控制与实际氨法脱硫工程中相差较大，忽略了酸/碱调pH值造成离子强度变化的影响，氨法脱硫吸收产物+4价硫的氧化过程机理并未得到合理的诠释。The oxidation of +4-valent sulfur in ammonia desulfurization absorption product is mainly affected by many conditions such as slurry pH value, +4-valent sulfur concentration, +6-valent sulfur concentration, oxidation air volume and temperature. So far, the research on ammonia desulfurization absorption product + 4-valent sulfur oxidation mainly focuses on the oxidation kinetics of ammonium sulfite, and the typical ones mainly include: ZhouJH et al. A certain concentration of O ₂ is introduced above the solution in the stirred reactor, and O ₂ diffuses into the solution and undergoes an oxidation reaction with ammonium sulfite. When the critical concentration is -1, it is 0.2 when the sulfite concentration is higher than the critical concentration. (Chemical Engineering Science, 2005, 60 (3): 863-868) such as ZhaoB (ChemicalEngineeringScience, 2005, 60 (3): 863-868) set up the single-bubble reaction device and carried out experimental research to the oxidation process of ammonium sulfite. When the sulfite concentration is higher than the critical concentration, it is grade 1, and when the concentration of sulfite is higher than the critical concentration, it is grade 0. The oxidation rate of ammonium sulfite increases with the increase of the pH value of the solution. When the pH value is between 6 and 9, the pH The effect of the value on the oxidation rate is linear. Although scholars have achieved some beneficial results in the study of ammonium sulfite oxidation, due to and Oxidation rate of the ammonia desulfurization absorption product + 4-valent sulfur which accounts for the majority cannot be measured separately. In addition, the control of the pH value in the experiment is quite different from that in the actual ammonia desulfurization project, ignoring the influence of acid/alkali adjustment of pH value caused by the change of ionic strength, the oxidation process of ammonia desulfurization absorption product + 4-valent sulfur The mechanism has not been properly explained.

在实际工程中，氨法脱硫吸收产物+4价硫往往在喷淋吸收塔底部的浆液池内被鼓入的空气氧化成为稳定的硫酸铵，其浆液池可近似看作是连续流全混釜鼓泡反应器，喷淋塔底部浆液池内浆液的温度一般在323.15K左右，+4价硫的氧化与浆液pH值、浆液中总硫浓度、氧化空气量和浆液在浆液池内的停留时间等因素有关。氧化率是衡量+4价硫氧化效果的主要指标，目前工程中主要依赖于经验控制氨法脱硫吸收产物+4价硫氧化的工艺条件，容易造成能源浪费或者+4价硫氧化率偏低，且不能维持浆液槽内的+4价硫氧化率的稳定，进而导致系统运行不稳定、硫酸铵副产品收得率低等问题。In actual engineering, the ammonia desulfurization absorption product + 4-valent sulfur is often oxidized into stable ammonium sulfate by the blown air in the slurry tank at the bottom of the spray absorption tower, and the slurry tank can be approximately regarded as a continuous flow fully mixed tank Bubble reactor, the temperature of the slurry in the slurry tank at the bottom of the spray tower is generally around 323.15K, and the oxidation of +4 valent sulfur is related to factors such as the pH value of the slurry, the total sulfur concentration in the slurry, the amount of oxidizing air, and the residence time of the slurry in the slurry tank. . Oxidation rate is the main index to measure the effect of +4-valent sulfur oxidation. At present, the project mainly relies on experience to control the process conditions of ammonia-based desulfurization absorption product +4-valent sulfur oxidation, which may easily cause energy waste or low +4-valent sulfur oxidation rate. Moreover, it cannot maintain the stability of the +4-valent sulfur oxidation rate in the slurry tank, which leads to problems such as unstable system operation and low yield of ammonium sulfate by-products.

因此，研究出一种能实现氨法脱硫吸收产物+4价硫高效、稳定氧化，且能够用于真实工程实践的系统，以及能够用于直接指导优化该氧化系统的设计和运行的模型就具有重要的理论意义和工程应用价值。Therefore, it is of great significance to develop a system that can realize the efficient and stable oxidation of ammonia desulfurization absorption product + 4-valent sulfur, and can be used in real engineering practice, as well as a model that can be used to directly guide and optimize the design and operation of the oxidation system. Important theoretical significance and engineering application value.

发明内容Contents of the invention

1.发明要解决的技术问题1. The technical problem to be solved by the invention

本发明的目的在于克服目前工程中所使用的氨法脱硫喷淋塔不能实现脱硫吸收产物+4价硫稳定、高效氧化，且其氧化工艺条件的控制主要依赖于经验，容易造成能源浪费、系统运行不稳定和硫酸铵副产品收率低的不足，提供了一种氨法脱硫吸收产物+4价硫氧化系统及其优化调控方法。通过使用本发明中+4价硫的氧化率模型，能够用于直接指导本发明中氨法脱硫吸收产物+4价硫氧化系统的优化设计和运行，从而可以使氨法脱硫吸收产物+4价硫的氧化率满足工业要求。The purpose of the present invention is to overcome the fact that the ammonia-based desulfurization spray tower used in current projects cannot achieve stable and efficient oxidation of desulfurization absorption products + 4-valent sulfur, and the control of its oxidation process conditions mainly depends on experience, which is likely to cause energy waste and system failure. Due to the shortcomings of unstable operation and low yield of ammonium sulfate by-products, an ammonia-based desulfurization absorption product + 4-valent sulfur oxidation system and its optimal regulation method are provided. By using the oxidation rate model of +4 valent sulfur in the present invention, it can be used to directly guide the optimal design and operation of the ammonia desulfurization absorption product + 4 valent sulfur oxidation system in the present invention, so that the ammonia desulfurization absorption product + 4 valent The oxidation rate of sulfur meets industrial requirements.

2.技术方案2. Technical solution

为达到上述目的，本发明提供的技术方案为：In order to achieve the above object, the technical scheme provided by the invention is:

其一，本发明的一种氨法脱硫吸收产物+4价硫氧化系统，包括喷淋塔本体，该喷淋塔本体内部自上而下依次包括除雾区、喷淋区和浆液池，其中，在所述的喷淋塔本体的顶部设有净烟气出口，在净烟气出口下方的除雾区设有除雾器，该除雾器与喷淋塔外部的工艺水箱相连；在所述的喷淋区的上部设有喷淋管，且在喷淋区下部对应的塔体一侧设有烟气进口；在所述的浆液池的底部设有空气分布器，该空气分布器的空气进口管道与氧化风机相连；在浆液池对应的塔体一侧通过采出管道与浆液采出泵相连，且该浆液池通过循环管道与喷淋管的进水口相连，在循环管道上还设有循环泵，与循环泵的进口连通的循环管道还与氨水进口管相连。First, an ammonia-based desulfurization absorption product + 4-valent sulfur oxidation system of the present invention includes a spray tower body, and the interior of the spray tower body includes a demisting area, a spraying area, and a slurry tank sequentially from top to bottom, wherein , the top of the spray tower body is provided with a clean flue gas outlet, and the demister area below the clean flue gas outlet is provided with a demister, which is connected to the process water tank outside the spray tower; The upper part of the spraying area is provided with a spraying pipe, and a flue gas inlet is provided on the side of the tower body corresponding to the lower part of the spraying area; an air distributor is provided at the bottom of the slurry tank, and the air distributor The air inlet pipe is connected to the oxidation fan; on the side of the tower body corresponding to the slurry tank, it is connected to the slurry production pump through the production pipeline, and the slurry tank is connected to the water inlet of the spray pipe through the circulation pipeline. There is a circulation pump, and the circulation pipeline connected with the inlet of the circulation pump is also connected with the ammonia water inlet pipe.

更进一步地，在与烟气进口和净烟气出口相连的管道上分别设有烟气在线监测系统。Furthermore, an online flue gas monitoring system is respectively installed on the pipes connected to the flue gas inlet and the net flue gas outlet.

更进一步地，在所述的浆液池内以及与循环泵出口相连的循环管道上均设有pH计。Furthermore, a pH meter is provided in the slurry pool and on the circulation pipeline connected to the outlet of the circulation pump.

其二，本发明的氨法脱硫吸收产物+4价硫氧化系统的优化调控方法，其步骤为：Its two, the optimization control method of the ammonia desulfurization absorption product+quaternary sulfur oxidation system of the present invention, its steps are:

步骤一、确定如下模型参数：氨法脱硫系统喷淋塔的D_R、G、F、Q，以及喷淋塔底部浆液池内浆液的pH、C_S、V、t_r、μ_L和σ_L；Step 1. Determine the following model parameters: D _R , G, F, Q, and the pH, C _S , V, t _r , μ _L and σ _L of the slurry in the slurry pool at the bottom of the spray tower;

其中，D_R为氨法脱硫系统喷淋塔的直径，通过测量直接获得，单位为m；G为由烟气进口进入喷淋塔内的待处理烟气的烟气流率，通过烟气在线监测系统测得，单位为m³·s^-1；和分别为喷淋塔烟气进口和净烟气出口烟气中SO₂的浓度，由烟气在线监测系统测得，单位为mg·m^-3；F为喷淋塔内的液气比，为系统运行的设定值，单位为L·m^-3；Q为喷淋塔浆液池内的氧化空气量，其值为理论空气量Q₀的1～4倍，单位为m³·s^-1；pH为浆液池内浆液的pH值；C_S为浆液池内浆液的总硫浓度，为+4价硫浓度和+6价硫浓度之和，其单位为mol·L^-1；V为浆液池内浆液的体积，通过调整浆液池内浆液的停留时间t_r进行控制，V＝60t_rL_in，单位为m³，该式中的L_in为通过喷淋管流进浆液池的浆液流率，单位为m³·s^-1，通过L_in＝F×G/1000m³·s^-1计算得到；浆液的粘度μ_L和表面张力σ_L分别利用粘度计和表面张力仪测得，其单位分别为Pa·s和N·m^-1；Among them, D _R is the diameter of the spray tower of the ammonia desulfurization system, which is directly obtained by measurement, and the unit is m; Measured by the monitoring system, the unit is m ³ ·s ^-1 ; and are the concentrations of SO ₂ in the flue gas at the flue gas inlet and the net flue gas outlet of the spray tower, measured by the flue gas online monitoring system, and the unit is mg m ^-3 ; F is the liquid-gas ratio in the spray tower, which is The set value of the system operation, the unit is L m ^-3 ; Q is the amount of oxidation air in the slurry pool of the spray tower, which is 1 to 4 times the theoretical air amount Q ₀ , and the unit is m ³ ·s ^-1 ; pH is the pH value of the slurry in the slurry tank; C _S is the total sulfur concentration of the slurry in the slurry tank, which is the +4-valent sulfur concentration and +6 valent sulfur concentration sum, its unit is mol·L ^-1 ; V is the volume of the slurry in the slurry tank, controlled by adjusting the residence time t _r of the slurry in the slurry tank, V=60t _r L _in , the unit is m ³ , the L in the formula _in is the flow rate of the slurry flowing into the slurry tank through the spray pipe, the unit is m ³ ·s ^-1 , calculated by L _in =F×G/1000m ³ ·s ^-1 ; the viscosity of the slurry μ _L and the surface tension σ _L is measured by viscometer and surface tension meter respectively, and its units are Pa·s and N·m ^-1 respectively;

步骤二、输入步骤一中的模型参数，并设定一初始pH值、氧化空气量Q以及C_S中+4价硫和+6价硫的初始浓度且满足利用+4价硫的氧化率模型计算浆液池内+4价硫的氧化率 Step 2, input the model parameters in step 1, and set an initial pH value, the amount of oxidizing air Q, and the initial concentrations of +4-valent _sulfur and +6-valent sulfur in CS and satisfied Calculating the Oxidation Rate of +4-valent Sulfur in the Slurry Tank Using the Oxidation Rate Model of +4-valent Sulfur

步骤三、将步骤二中计算得到的+4价硫的氧化率带入下式进行检验：Step 3, the oxidation rate of +4 valent sulfur calculated in step 2 Enter the following formula for inspection:

$| | \frac{{r r}_{((I I V V))} V V}{{M m}_{{SO SO}_{22}}} - - \frac{{C C}_{{S S}^{66 + +}}}{{C C}_{s the s}} | | \leq \leq 0.001 0.001$

若计算得到的+4价硫的氧化率不满足上式，返回至步骤二中调整和的值，若 $r_{(I V)} V / M_{{SO}_{2}} < C_{S^{6 +}} / C_{S},$ 则增大并减小若 $r_{(I V)} V / M_{{SO}_{2}} > C_{S^{6 +}} / C_{S},$ 则减小并增大重新计算r_(IV)V直至上式成立，最后输出和+4价硫的氧化率 If the calculated oxidation rate of +4-valent sulfur If the above formula is not satisfied, return to step 2 for adjustment and value, if $r_{(I V)} V / m_{{SO}_{2}} < C_{S^{6 +}} / C_{S},$ increase and reduce like $r_{(I V)} V / m_{{SO}_{2}} > C_{S^{6 +}} / C_{S},$ then decrease and increase Recalculate r _(IV) V until the above formula is established, and finally output and the oxidation rate of +4-valent sulfur

步骤四、将步骤三中输出的+4价硫氧化率与实际工程中的目标设定值进行比较，若模型计算值低于目标设定值，则返回至步骤二中按如下方法调整参数pH、Q和C_S中的一个或多个，并重新进行计算，直到步骤三中输出的+4价硫氧化率满足工程要求：Step 4, the +4 valent sulfur oxidation rate output in step 3 Compared with the target set value in the actual project, if the model calculated value Lower than the target setting value, then return to step two to adjust one or more of the parameters pH, Q and C _S as follows, and recalculate until the +4-valent sulfur oxidation rate output in step three Meet engineering requirements:

降低浆液池内浆液的pH，步长为0.1；增大氧化空气量Q，步长为0.5；降低浆液池内浆液的总硫浓度C_S，步长为0.1，C_S的降低通过增大由浆液采出泵采出的浆液流率L_out来实现。Decrease the pH of the slurry in the slurry tank with a step size of 0.1; increase the amount of oxidizing air Q with a step size of 0.5; reduce the total _sulfur concentration _CS of the slurry in the slurry tank with a step size of 0.1. It is realized by the slurry flow rate L _out produced by the pump.

更进一步地，步骤二中浆液池内+4价硫的氧化率按以下模型进行计算：Furthermore, the oxidation rate of +4 valent sulfur in the slurry tank in step 2 is calculated according to the following model:

$η η = = {r r}_{((I I V V))} V V / / {M m}_{{SO SO}_{22}} - - - - - - ((11)),,$

式(1)中的为喷淋塔喷淋区吸收的SO₂的摩尔流率，单位为mol·s^-1，其通过式(2)进行计算：In formula (1) is the molar flow rate of SO ₂ absorbed in the spray zone of the spray tower, the unit is mol·s ^-1 , which is calculated by formula (2):

${M m}_{{SO SO}_{22}} = = G G \times \times (({C C}_{{SO SO}_{22},, i i n no} - - {C C}_{{SO SO}_{22},, o o u u t t})) / / ((10001000 \times \times 6464)) - - - - - - ((22)),,$

式(1)中的r_(IV)为浆液池内+4价硫的氧化速率，单位为mol·L^-1·min^-1，其按式(3)进行计算：r _(IV) in formula (1) is the oxidation rate of +4-valent sulfur in the slurry tank, the unit is mol L ^-1 min ^-1 , which is calculated according to formula (3):

${r r}_{((I I V V))} = = {C C}_{{O o}_{22}}^{* *} / / ((\frac{11}{{k k}_{L L} a a} + + \frac{11}{{k k}_{00} exp exp ((\frac{- - 2.8 2.8 \times \times 1010^{44}}{R R T T}))} \cdot &Center Dot; \frac{11}{1010^{- - 0.39 0.39 p p H h - - 1.14 1.14}} \cdot \cdot \frac{11}{{C C}_{{SO SO}_{33}^{22 - -}}^{- - 0.5 0.5}} \cdot &Center Dot; \frac{11}{- - 44 {C C}_{{S S}^{66 + +}} + + 99})) - - - - - - ((33)),,$

式(3)中，k₀为频率因子，其值为1.44×10⁴；R为理想气体常数，为8.31J·mol^-1·K^-1；T为喷淋塔内温度，单位为K；为浆液池内气液界面处氧的平衡浓度，单位为mol·L^-1，其通过式(4)进行计算：In formula (3), k ₀ is the frequency factor, and its value is 1.44×10 ⁴ ; R is the ideal gas constant, which is 8.31J·mol ^-1 ·K ^-1 ; T is the temperature inside the spray tower, and the unit is K; is the equilibrium concentration of oxygen at the gas-liquid interface in the slurry pool, in mol·L ^-1 , which is calculated by formula (4):

${C C}_{{O o}_{22}}^{* *} = = {Hp HP}_{{O o}_{22}}^{* *} - - - - - - ((44)),,$

式(4)中，为浆液池内气液界面处O₂的平衡分压，单位为Pa；H为O₂在浆液池内浆液中的溶解度系数，单位为mol·m^-3·Pa^-1，H按式(5)进行计算：In formula (4), is the equilibrium partial pressure of O ₂ at the gas-liquid interface in the slurry tank, in Pa; H is the solubility coefficient of O ₂ in the slurry in the slurry tank, in mol·m ^-3 ·Pa ^-1 , and H is calculated according to formula (5) calculate:

$l l o o g g ((\frac{{H h}^{00}}{H h})) = = {h h}_{11} {I I}_{11} + + {h h}_{22} {I I}_{22} + + ... ... + + {h h}_{i i} {I I}_{i i} + + ... ... - - - - - - ((55)),,$

式(5)中，H⁰为O₂在水中的溶解度系数；h_i为浆液池内电解质引起的O₂溶解度降低系数，单位为m³·kion^-1；I_i液池内电解质中各离子的离子强度，单位为kion·m^-3，h_i和I_i分别通过式(6)和式(7)进行计算：In formula (5), H ⁰ is the solubility coefficient of O ₂ in water; h _i is the solubility reduction coefficient of O ₂ caused by the electrolyte in the slurry pool, and the unit is m ³ ·kion ^-1 ; I _i is the ion of each ion in the electrolyte in the liquid pool Intensity, the unit is kion m ^-3 , h _i and I _i are calculated by formula (6) and formula (7):

h_i＝h⁺+h^-+h_G(6)，h _i =h ⁺ +h ^- +h _G (6),

${I I}_{i i} = = \frac{11}{22} {ΣC ΣC}_{i i} {Z Z}_{i i}^{22} - - - - - - ((77)),,$

式(6)中，h⁺、h^-、h_G分别为该电解质正、负离子及被溶解的氧气引起的数值；式(7)中C_i为浆液池内电解质的各离子的浓度，Z_i为各离子的价数；在氨法脱硫工艺中控制的pH值范围内，浆液中H₂SO₃和NH₃·H₂O的浓度低，可以忽略不计，浆液中的电解质是指NH₄HSO₃、(NH₄)₂SO₃和(NH₄)₂SO₄；In formula (6), h ⁺ , h ^- , h _G are values caused by positive and negative ions of the electrolyte and dissolved oxygen respectively; in formula (7), C _i is the concentration of each ion in the electrolyte in the slurry pool, and _Zi is The valence of each ion; within the pH range controlled in the ammonia desulfurization process, the concentrations of H ₂ SO ₃ and NH ₃ ·H ₂ O in the slurry are low and negligible, and the electrolyte in the slurry refers to NH ₄ HSO ₃ , (NH ₄ ) ₂ SO ₃ and (NH ₄ ) ₂ SO ₄ ;

式(3)中，k_L为氧气在液相中的传质系数，单位为m·s^-1，其按式(8)进行计算：In formula (3), k _L is the mass transfer coefficient of oxygen in the liquid phase, the unit is m·s ^-1 , which is calculated according to formula (8):

${k k}_{L L} = = 0.5 0.5 {g g}^{55 / / 88} {D D.}_{{O o}_{22}}^{11 / / 22} {ρ ρ}_{L L}^{33 / / 88} {σ σ}_{L L}^{- - 33 / / 88} {d d}_{v v s the s}^{11 / / 22} - - - - - - ((88)),,$

式(8)中，ρ_L为浆液池内浆液的密度，单位为kg·m^-3，其通过式(9)计算得到：In the formula (8), ρ _L is the density of the slurry in the slurry tank, the unit is kg·m ^-3 , which is calculated by the formula (9):

${ρ ρ}_{L L} = = ((9999 {δ δ}_{11} {C C}_{{S S}^{44 + +}} + + 116116 {δ δ}_{22} {C C}_{{S S}^{44 + +}} + + 132132 {C C}_{{S S}^{66 + +}})) / / 10001000 - - - - - - ((99)),,$

式(9)中，δ₁和δ₂分别为和的分布系数，其中：In formula (9), δ ₁ and δ ₂ are respectively and The distribution coefficient of , where:

${δ δ}_{11} = = \frac{{K K}_{a a 11} [[{H h}^{+ +}]]}{{[[{H h}^{+ +}]]}^{22} + + {K K}_{a a 11} [[{H h}^{+ +}]] + + {K K}_{a a 11} {K K}_{a a 22}} - - - - - - ((1010)),,$

${δ δ}_{22} = = \frac{{K K}_{a a 11} {K K}_{a a 22}}{{[[{H h}^{+ +}]]}^{22} + + {K K}_{a a 11} [[{H h}^{+ +}]] + + {K K}_{a a 11} {K K}_{a a 22}} - - - - - - ((1111)),,$

式(10)和(11)中，K_a1和K_a2分别为平衡反应和的反应平衡常数；[H⁺]为浆液池(501)内浆液中氢离子的活性浓度，通过pH值计算得到；In formulas (10) and (11), K _a1 and K _a2 are equilibrium reactions respectively and [H ⁺ ] is the active concentration of hydrogen ions in the slurry in the slurry pool (501), calculated by the pH value;

式(8)中和d_vs分别为氧在浆液池液相中的扩散系数和浆液池液相中气泡的平均直径，其单位分别为m²·s^-1和m，和d_vs分别按式(12)、(13)进行计算：In formula (8) and d _vs are the diffusion coefficient of oxygen in the liquid phase of the slurry pool and the average diameter of bubbles in the liquid phase of the slurry pool, and their units are m ² ·s ^-1 and m, respectively, and d _vs are calculated according to equations (12) and (13) respectively:

${D D.}_{{O o}_{22}} = = \frac{7.4 7.4 \times \times 1010^{- - 1212} {(({αM αM}_{B B}))}^{0.5 0.5} T T}{{μ μ}_{L L} {V V}_{A A}^{0.6 0.6}} - - - - - - ((1212)),,$

${d d}_{v v s the s} = = 2626 {D D.}_{R R} {((\frac{{gD gD}_{R R}^{22}}{{σ σ}_{L L}}))}^{- - 0.5 0.5} {((\frac{{gD gD}_{R R}^{33} {ρ ρ}_{L L}^{22}}{{μ μ}_{L L}^{22}}))}^{- - 0.12 0.12} {((\frac{{u u}_{O o G G}}{\sqrt{{gD gD}_{R R}}}))}^{- - 0.12 0.12} - - - - - - ((1313)),,$

式(12)中，α为浆液池内浆液中溶剂的缔合因子，值为2.6；M_B为浆液池内浆液中溶剂的摩尔质量，单位为g·mol^-1；V_A为氧分子的扩散体积，单位为cm³·mol^-1；In formula (12), α is the association factor of the solvent in the slurry in the slurry pool, with a value of 2.6; _M _B is the molar mass of the solvent in the slurry in the slurry pool, and the unit is g mol ⁻¹ ; VA is the diffusion volume of oxygen molecules , the unit is cm ³ ·mol ^-1 ;

式(13)中，u_OG为浆液池内氧化空气的表观气速，单位为m·s^-1，其按式(14)进行计算：In formula (13), u _OG is the superficial gas velocity of the oxidizing air in the slurry tank, the unit is m s ^-1 , which is calculated according to formula (14):

${u u}_{O o G G} = = Q Q / / (({πD πD}_{R R}^{22} / / 44)) - - - - - - ((1414)),,$

式(3)中，a为气液接触界面面积，单位为m²·m^-3，按式(15)进行计算：In formula (3), a is the gas-liquid contact interface area in m ² ·m ^-3 , calculated according to formula (15):

$a a = = \frac{66 {ϵ ϵ}_{G G}}{{d d}_{V V S S}} - - - - - - ((1515)),,$

式(15)中，浆液池内液相中的气含率ε_G按下式进行计算：In formula (15), the gas holdup ε _G in the liquid phase in the slurry pool is calculated as follows:

$\frac{{ϵ ϵ}_{G G}}{{((11 - - {ϵ ϵ}_{G G}))}^{44}} = = 0.25 0.25 \times \times ((\frac{{u u}_{O o G G} {μ μ}_{L L}}{{σ σ}_{L L}})) {((\frac{{ρ ρ}_{L L} {σ σ}_{L L}^{33}}{{gμ gμ}_{L L}^{44}}))}^{77 / / 24 twenty four} - - - - - - ((1616)),,$

式(3)中，的浓度按下式进行计算：In formula (3), concentration Calculate as follows:

${C C}_{{SO SO}_{33}^{22 - -}} = = {δ δ}_{22} {C C}_{{S S}^{44 + +}} - - - - - - ((1717)),,$

联立式(1)～(17)即计算出浆液池内+4价硫的氧化率 Simultaneous formulas (1) to (17) calculate the oxidation rate of +4-valent sulfur in the slurry tank

更进一步地，步骤四中调整参数pH、Q、C_S的参数范围要求如下：浆液池内浆液的pH为5.0～6.0，C_s为1.9～2.3mol/L，实际氧化空气量Q与理论氧化空气量Q₀之比m的范围为1～4。Furthermore, the parameter range requirements for adjusting the parameters pH, Q, and CS in step 4 are as follows: the pH of the slurry in the slurry tank is _{5.0-6.0, the C s} _is 1.9-2.3 mol/L, the actual amount of oxidizing air Q is the same as the theoretical amount of oxidizing air The ratio m of the quantity Q ₀ ranges from 1 to 4.

氨法脱硫吸收产物+4价硫的氧化在喷淋塔底部浆液池内进行，稳定运行条件下浆液池可近似看作连续流全混鼓泡反应器，另外，+4价硫的氧化率主要与pH值、总硫浓度、氧化空气量及浆液在浆液池内的停留时间等因素有关。基于上述特点，本发明结合+4价硫氧化速率方程，建立浆液池内+4价硫氧化的数学模型。The oxidation of the ammonia desulfurization absorption product +4-valent sulfur is carried out in the slurry tank at the bottom of the spray tower. Under stable operating conditions, the slurry tank can be approximately regarded as a continuous flow fully mixed bubbling reactor. In addition, the oxidation rate of +4-valent sulfur is mainly related to It is related to factors such as pH value, total sulfur concentration, amount of oxidizing air and residence time of slurry in the slurry tank. Based on the above characteristics, the present invention combines the +4-valent sulfur oxidation rate equation to establish a mathematical model for +4-valent sulfur oxidation in the slurry tank.

本发明中浆液池内+4价硫的氧化率公式的推导过程如下：The oxidation rate formula of +4 valent sulfur in the slurry tank in the present invention The derivation process is as follows:

稳态条件下，可将图1中的氨法脱硫喷淋塔内的浆液池简化为如图2所示的模型，流进和流出浆液池的浆液存在如下平衡关系：Under steady-state conditions, the slurry tank in the ammonia desulfurization spray tower in Figure 1 can be simplified to the model shown in Figure 2, and the slurry flowing into and out of the slurry tank has the following equilibrium relationship:

L_in＝L_out+L_re(18)，L _in = L _out + L _re (18),

式(1)中，L_in为由喷淋管进入浆液池的浆液流率，L_out为通过浆液采出泵排出浆液池的浆液流率，L_re为通过循环泵由浆液池抽出的浆液流率，其单位均为m³·s^-1；其中，L_in＝F×G/1000m³·s^-1，为了维持浆液池内浆液浓度的恒定，使部分浆液排出浆液池并进行后续结晶处理，排出浆液池的这部分浆液的流率可按式(19)进行计算：In formula (1), L _in is the slurry flow rate entering the slurry tank from the spray pipe, L _out is the slurry flow rate discharged from the slurry tank through the slurry extraction pump, and L _re is the slurry flow drawn from the slurry tank through the circulating pump rate, the unit of which is m ³ ·s ^-1 ; among them, Lin = F×G/1000m ³ ·s ^-1 , _in order to maintain a constant concentration of the slurry in the slurry pool, part of the slurry is discharged from the slurry pool for subsequent crystallization treatment, The flow rate of this part of the slurry discharged from the slurry pool can be calculated according to formula (19):

${L L}_{o o u u t t} (({C C}_{{S S}^{44 + +}} + + {C C}_{{S S}^{66 + +}})) = = {M m}_{{SO SO}_{22}} - - - - - - ((1919)),,$

浆液池内各离子浓度随时间的变化速率可表达为：The change rate of each ion concentration in the slurry pool with time can be expressed as:

$\frac{{dC c}_{i i}}{d d t t} = = (({N N}_{i i} + + {r r}_{r r e e a a c c t t})) / / V V - - - - - - ((2020)),,$

式(20)中，N_i为浆液池进、出口浆液中离子的摩尔流率，单位为mol·min^-1，其可通过式(21)进行计算：In formula (20), N _i is the molar flow rate of ions in the slurry at the inlet and outlet of the slurry tank, and the unit is mol·min ^-1 , which can be calculated by formula (21):

N_i＝L_inC_i,in-L_reC_i,re-L_outC_i,out(21)，N _i =L _in C _i,in -L _re C _i,re -L _out C _i,out (21),

式(21)中C_i,in、C_i,re和C_i,out分别为由喷淋管进入浆液池的、通过循环泵由浆液池抽出的、通过浆液采出泵排出浆液池的浆液中的离子浓度；结合式(20)、(21)，浆液池内+4价硫和+6价硫离子浓度随时间的变化速率分别为：In formula (21), C _i,in , C _i,re and C _i,out are respectively the slurry in the slurry that enters the slurry tank from the spray pipe, is extracted from the slurry tank through the circulating pump, and is discharged from the slurry tank through the slurry extraction pump. ion concentration; combined with formula (20), (21), the rate of change of +4 valent sulfur and +6 valent sulfur ion concentration with time in the slurry tank is respectively:

$\frac{d d (({C C}_{{SO SO}_{33}^{22 - -}} + + {C C}_{{HSO HSO}_{33}^{- -}} + + {C C}_{{H h}_{22} {SO SO}_{33}}))}{d d t t} = = (({N N}_{{SO SO}_{33}^{22 - -}} + + {N N}_{{HSO HSO}_{33}^{- -}} + + {N N}_{{H h}_{22} {SO SO}_{33}} - - {r r}_{r r e e a a c c t t})) / / V V - - - - - - ((22 twenty two)),,$

$\frac{{dC c}_{{SO SO}_{44}^{22 - -}}}{d d t t} = = (({N N}_{{SO SO}_{44}^{22 - -}} + + {r r}_{r r e e a a c c t t})) / / V V - - - - - - ((23 twenty three)),,$

在喷淋区，SO₂被吸收进入液相并形成+4价硫(H₂SO₃、和)，SO₂吸收量为喷淋区形成的+4价硫进入浆液池内并部分被氧化成为+6价硫。氨法脱硫+4价硫氧化过程中，+4价硫浓度减少的速率等于+6价硫浓度增加的速率，且稳态条件下浆液池内浆液离子浓度保持恒定，因此，式(22)、(23)中+4价硫和+6价硫离子浓度随时间的变化速率均为0，即：则有：In the spray zone, SO ₂ is absorbed into the liquid phase and forms +4-valent sulfur (H ₂ SO ₃ , and ), the SO ₂ absorption is The +4-valent sulfur formed in the spray area enters the slurry tank and is partially oxidized to +6-valent sulfur. In the process of ammonia desulfurization + 4-valent sulfur oxidation, the rate of decrease of +4-valent sulfur concentration is equal to the rate of increase of +6-valent sulfur concentration, and the concentration of slurry ions in the slurry pool remains constant under steady-state conditions. Therefore, equations (22), ( In 23), the rate of change of the concentration of +4-valent sulfur and +6-valent sulfur ion with time is 0, that is: then:

若+4价硫的氧化率为η，则： If the oxidation rate of +4 valent sulfur is η, then:

式(22)～(24)中，r_react为浆液池内+6价硫的生成速率，单位为mol·min^-1，其可根据下式进行计算：In formulas (22)-(24), r _react is the generation rate of +6-valent sulfur in the slurry tank, in mol·min ^-1 , which can be calculated according to the following formula:

r_react＝r_(IV)V(26)；r _react = r _(IV) V(26);

将式(25)、(26)代入式(24)，即可得+4价硫的氧化率： Substituting formulas (25) and (26) into formula (24), the oxidation rate of +4-valent sulfur can be obtained:

本发明中浆液池内浆液的密度计算公式推导如下：The density calculation formula of the slurry in the slurry tank in the present invention The derivation is as follows:

氨法脱硫过程中，SO₂溶解进入液相并发生如下离子平衡：During the ammonia desulfurization process, SO2 dissolves into the liquid phase and the ion balance occurs as follows _:

浆液中+4价硫中H₂SO₃,和的分布系数δ₀、δ₁和δ₂可分别表述为：+4 valent sulfur in slurry H ₂ SO ₃ , and The distribution coefficients δ ₀ , δ ₁ and δ ₂ of can be expressed as:

${δ δ}_{00} = = \frac{[[{H h}_{22} {SO SO}_{33}]]}{[[{H h}_{22} {SO SO}_{33}]] + + [[{HSO HSO}_{33}^{- -}]] + + [[{SO SO}_{33}^{22 - -}]]} - - - - - - ((3030)),,$

${δ δ}_{11} = = \frac{[[{HSO HSO}_{33}^{- -}]]}{[[{H h}_{22} {SO SO}_{33}]] + + [[{HSO HSO}_{33}^{- -}]] + + [[{SO SO}_{33}^{22 - -}]]} - - - - - - ((3131)),,$

${δ δ}_{22} = = \frac{[[{SO SO}_{33}^{22 - -}]]}{[[{H h}_{22} {SO SO}_{33}]] + + [[{HSO HSO}_{33}^{- -}]] + + [[{SO SO}_{33}^{22 - -}]]} - - - - - - ((3232)),,$

结合式(27)～(29)，和的浓度可分别表述为:Combined formula (27)～(29), and concentrations can be expressed as:

$\frac{[[{H h}^{+ +}]] [[{HSO HSO}_{33}^{- -}]]}{[[{H h}_{22} {SO SO}_{33}]]} = = {K K}_{a a 11} &DoubleRightArrow; &DoubleRightArrow; [[{HSO HSO}_{33}^{- -}]] = = \frac{{K K}_{a a 11} [[{H h}_{22} {SO SO}_{33}]]}{[[{H h}^{+ +}]]} - - - - - - ((3333)),,$

$\frac{[[{H h}^{+ +}]] [[{SO SO}_{33}^{22 - -}]]}{[[{HSO HSO}_{33}^{22 - -}]]} = = {K K}_{a a 22} &DoubleRightArrow; &DoubleRightArrow; [[{SO SO}_{33}^{22 - -}]] = = \frac{{K K}_{a a 22} [[{HSO HSO}_{33}^{- -}]]}{[[{H h}^{+ +}]]} - - - - - - ((3434)),,$

结合式(30)～(34)，H₂SO₃、和的分布系数δ₀、δ₁和δ₂可分别化为：Combining formulas (30) to (34), H ₂ SO ₃ , and The distribution coefficients δ ₀ , δ ₁ and δ ₂ of can be transformed into:

${δ δ}_{00} = = \frac{{[[{H h}^{+ +}]]}^{22}}{{[[{H h}^{+ +}]]}^{22} + + {K K}_{a a 11} [[{H h}^{+ +}]] + + {K K}_{a a 11} {K K}_{a a 22}} - - - - - - ((3535)),,$

${δ δ}_{11} = = \frac{{K K}_{a a 11} [[{H h}^{+ +}]]}{{[[{H h}^{+ +}]]}^{22} + + {K K}_{a a 11} [[{H h}^{+ +}]] + + {K K}_{a a 11} {K K}_{a a 22}} - - - - - - ((3636)),,$

${δ δ}_{22} = = \frac{{K K}_{a a 11} {K K}_{a a 22}}{{[[{H h}^{+ +}]]}^{22} + + {K K}_{a a 11} [[{H h}^{+ +}]] + + {K K}_{a a 11} {K K}_{a a 22}} - - - - - - ((3737)),,$

从式(35)～(37)中可以看出，H₂SO₃,和的分布系数δ₀、δ₁和δ₂为pH值的函数。而由式(35)可知，在pH为5.0～6.0的范围内，H₂SO₃的分布系数δ₀数值很小，可以忽略。浆液中的浓度为δ₁ 的浓度为δ₂ 溶液中主要是NH₄HSO₃、(NH₄)₂SO₃和(NH₄)₂SO₄，因此，浆液的密度ρ_L可近似按下式进行计算：From formulas (35) to (37), it can be seen that H ₂ SO ₃ , and The distribution coefficients δ ₀ , δ ₁ and δ ₂ are functions of pH. However, it can be known from formula (35) that within the pH range of 5.0-6.0, the distribution coefficient δ ₀ of H ₂ SO ₃ is very small and can be ignored. Serum middle The concentration is δ ₁ The concentration is δ ₂ The solution mainly contains NH ₄ HSO ₃ , (NH ₄ ) ₂ SO ₃ and (NH ₄ ) ₂ SO ₄ , therefore, the density ρ _L of the slurry can be calculated approximately as follows:

${ρ ρ}_{L L} = = ((9999 {δ δ}_{11} {C C}_{{S S}^{44 + +}} + + 116116 {δ δ}_{22} {C C}_{{S S}^{44 + +}} + + 132132 {C C}_{{S S}^{66 + +}})) / / 1000. 1000.$

本发明中的各模型参数如表一所示。Each model parameter in the present invention is as shown in Table 1.

表1本发明的模型参数说明Table 1 Model parameter description of the present invention

3.有益效果3. Beneficial effects

采用本发明提供的技术方案，与现有技术相比，具有如下显著效果：Compared with the prior art, the technical solution provided by the invention has the following remarkable effects:

(1)本发明的氨法脱硫吸收产物+4价硫氧化系统，待处理烟气进入喷淋塔后，在喷淋区与通过喷淋管喷淋而下的喷淋液逆流接触后落入浆液池内，在浆液池底部设置的空气分布器能够使浆液与氧气充分接触，促进+4价硫的氧化。本发明中在浆液池对应的塔体一侧通过采出管道与浆液采出泵相连，从而可以使浆液不断从浆液池排出，有利于维持浆液池内的离子浓度，保证浆液池内+4价硫氧化的稳定和高效进行；本发明中的浆液池通过循环管道与喷淋管的进水口相连，在循环管道上还设有循环泵，与循环泵的进口连通的循环管道还与氨水进口管相连，从而可以使浆液循环使用，有利于节约资源，且通过氨水进口管不断注入新鲜氨水，有利于调节进入喷淋管内喷淋液的pH，保证了喷淋液吸收SO₂的能力。(1) In the ammonia desulfurization absorption product + tetravalent sulfur oxidation system of the present invention, after the flue gas to be treated enters the spray tower, it falls into the In the slurry tank, the air distributor installed at the bottom of the slurry tank can make the slurry fully contact with oxygen and promote the oxidation of +4 valent sulfur. In the present invention, the side of the tower body corresponding to the slurry pool is connected to the slurry extraction pump through the extraction pipeline, so that the slurry can be continuously discharged from the slurry pool, which is beneficial to maintaining the ion concentration in the slurry pool and ensuring the oxidation of +4-valent sulfur in the slurry pool stable and efficient; the slurry pool in the present invention is connected to the water inlet of the spray pipe through a circulation pipeline, and a circulation pump is also arranged on the circulation pipeline, and the circulation pipeline connected with the inlet of the circulation pump is also connected with the ammonia water inlet pipe, Therefore, the slurry can be recycled, which is beneficial to save resources, and the continuous injection of fresh ammonia water through the ammonia water inlet pipe is conducive to adjusting the pH of the spray liquid entering the spray pipe, ensuring the ability of the spray liquid to absorb SO ₂ .

(2)本发明的氨法脱硫吸收产物+4价硫氧化系统的优化调控方法，是基于氨法脱硫吸收产物+4价硫氧化工艺的特点，建立数学模型对工程实践中喷淋塔浆液池内+4价的氧化过程进行数值模拟，采用该模型能够计算不同工艺条件下+4价硫的氧化率，通过模型计算值与设定值之间的检验公式对计算结果进行对比检验，并结合工程实际来调节氧化槽内+4价硫氧化的Cs、pH和Q等工艺参数，使+4价硫的氧化率能够满足工程要求，从而能够指导氨法脱硫吸收产物+4价硫氧化系统的设计和运行，有利于氨法脱硫吸收产物+4价硫氧化系统的优化。(2) The optimal regulation and control method of the ammonia desulfurization absorption product+quaternary sulfur oxidation system of the present invention is based on the characteristics of the ammonia desulfurization absorption product+quaternary sulfur oxidation process, and establishes a mathematical model for the spray tower slurry tank in engineering practice The oxidation process of +4 valence is numerically simulated. This model can be used to calculate the oxidation rate of +4 valent sulfur under different process conditions. The calculation results are compared and tested by the test formula between the model calculated value and the set value, and combined with the project Actually adjust the process parameters such as Cs, pH and Q of +4 valent sulfur oxidation in the oxidation tank, so that the oxidation rate of +4 valent sulfur can meet the engineering requirements, so as to guide the design of the ammonia desulfurization absorption product + 4 valent sulfur oxidation system And operation, which is conducive to the optimization of ammonia desulfurization absorption product + 4-valent sulfur oxidation system.

(3)本发明的氨法脱硫吸收产物+4价硫氧化系统的优化调控方法，其模型计算值与工程测量值间的误差小于5％，模型能够较为准确的模拟氨法脱硫吸收产物+4价硫的氧化过程，从而使氨法脱硫吸收产物+4价硫氧化系统的设计和运行更加可靠，提高了氨法脱硫系统运行的稳定性和经济性。(3) The optimization control method of the ammonia desulfurization absorption product+quaternary sulfur oxidation system of the present invention, the error between the model calculation value and the engineering measurement value is less than 5%, and the model can more accurately simulate the ammonia desulfurization absorption product+4 The oxidation process of valent sulfur makes the design and operation of ammonia desulfurization absorption product + 4 valent sulfur oxidation system more reliable, and improves the stability and economy of ammonia desulfurization system operation.

附图说明Description of drawings

图1为本发明的氨法脱硫吸收产物+4价硫氧化系统的结构示意图；Fig. 1 is the structural representation of the ammonia desulfurization absorption product+quaternary sulfur oxidation system of the present invention;

图2为本发明中喷淋塔内浆液池模型的示意图；Fig. 2 is the schematic diagram of the slurry pond model in the spray tower among the present invention;

图3为本发明中的模型计算框图；Fig. 3 is a model calculation block diagram among the present invention;

图4为+4价硫氧化率的实测值与本发明中的模型计算值的对比图。Fig. 4 is a comparison chart of the measured value of +4-valent sulfur oxidation rate and the calculated value of the model in the present invention.

图中的标号说明：Explanation of the symbols in the figure:

1、氧化风机；2、空气分布器；3、浆液采出泵；4、循环泵；5、喷淋塔本体；501、浆液池；502、喷淋区；503、烟气进口；504、喷淋管；505、除雾器；506、净烟气出口；6、氨水进口管；7、取样口。1. Oxidation fan; 2. Air distributor; 3. Serum extraction pump; 4. Circulation pump; 5. Spray tower body; 501. Serum tank; 502. Spray area; Shower pipe; 505, mist eliminator; 506, net flue gas outlet; 6, ammonia water inlet pipe; 7, sampling port.

具体实施方式Detailed ways

为进一步了解本发明的内容，现结合附图和实施例对本发明作详细描述。In order to further understand the content of the present invention, the present invention will be described in detail in conjunction with the accompanying drawings and embodiments.

实施例1Example 1

如图1所示，本实施例的一种氨法脱硫吸收产物+4价硫氧化系统，包括喷淋塔本体5，该喷淋塔本体5内部自上而下依次包括除雾区、喷淋区502和浆液池501，其中，在喷淋塔本体5的顶部设有净烟气出口506，在净烟气出口506下方的除雾区设有除雾器505，该除雾器505与喷淋塔外部的工艺水箱相连。在喷淋区502的上部设有喷淋管504，且在喷淋区502下部对应的塔体一侧设有烟气进口503，在与烟气进口503和净烟气出口506相连的管道上均设有烟气在线监测系统。在浆液池501的底部设有空气分布器2，该空气分布器2的空气进口管道与氧化风机1相连；在浆液池501对应的塔体一侧通过采出管道与浆液采出泵3相连，且该浆液池501通过循环管道与喷淋管504的进水口相连。在循环管道上还设有循环泵4，在该循环管道上靠近循环浆液出口的一端设有取样口7，且与循环泵4的进口连通的循环管道还与氨水进口管6相连。在浆液池501内以及与该循环泵4出口连通的循环管道上均设有pH计，从而可以实时测量浆液池内浆液和通入氨水调节后进入喷淋管的喷淋液的pH值。As shown in Figure 1, an ammonia-based desulfurization absorption product + 4-valent sulfur oxidation system in this embodiment includes a spray tower body 5, and the interior of the spray tower body 5 sequentially includes a demisting area, a spray Area 502 and slurry tank 501, wherein, the top of the spray tower body 5 is provided with a net flue gas outlet 506, and the mist removal area below the net flue gas outlet 506 is provided with a mist eliminator 505, which is connected with the spray The process water tank outside the shower tower is connected. A spray pipe 504 is provided on the upper part of the spray area 502, and a flue gas inlet 503 is provided on the side of the tower body corresponding to the lower part of the spray area 502, and a pipe connected to the flue gas inlet 503 and the net flue gas outlet 506 All are equipped with online flue gas monitoring system. An air distributor 2 is arranged at the bottom of the slurry pool 501, and the air inlet pipe of the air distributor 2 is connected with the oxidation blower 1; the side of the tower body corresponding to the slurry pool 501 is connected with the slurry extraction pump 3 through a production pipeline, And the slurry pool 501 is connected with the water inlet of the spray pipe 504 through a circulation pipeline. A circulation pump 4 is also provided on the circulation pipeline, and a sampling port 7 is provided on the circulation pipeline near the outlet of the circulating slurry, and the circulation pipeline connected with the inlet of the circulation pump 4 is also connected with the ammonia water inlet pipe 6 . A pH meter is provided in the slurry tank 501 and on the circulating pipeline connected with the outlet of the circulating pump 4, so that the pH value of the slurry in the slurry tank and the spray liquid entering the spray pipe after being adjusted by feeding ammonia water can be measured in real time.

本实施例中，待处理烟气通过喷淋塔本体5上的烟气进口503进入喷淋塔后折转向上，在喷淋区502与由喷淋管504喷淋而下的浆液逆流接触，大大提高了对烟气中SO₂的脱除效果。在喷淋区SO₂溶解进入液相并与喷淋液中吸收剂反应生成+4价硫(NH₄)₂SO₃和NH₄HSO₃，脱除了SO₂的烟气继续向上进行水洗处理和除雾器505的除雾处理，最终得到的净烟气通过塔顶的净烟气出口506排出，而吸收了SO₂的浆液则落入喷淋塔底部的浆液池501内。通过浆液池501底部的空气分布器2持续不断地向浆液池501内通入氧气，以将+4价硫(NH₄)₂SO₃和NH₄HSO₃氧化成稳定的+6价硫(NH₄)₂SO₄。在运行过程中，一方面通过浆液采出泵3不断使浆液池501内的部分浆液由浆液出口排出，进行后续的结晶处理，从而可以维持浆液池501内离子浓度的恒定，使浆液池501内+4价硫(NH₄)₂SO₃和NH₄HSO₃的氧化率能够维持恒定。另一方面通过循环泵4抽取浆液池501内的浆液送至喷淋管504进行循环利用，从而可以节约资源。在与循环泵4进口连通的循环管路还与氨水进口管6相连，从而可以不断向喷淋液中补充氨水以保持喷淋液对SO₂的吸收能力，可以通过测量的浆液池501内浆液的pH来调节氨水进口管6中氨水的补充量，以使补充氨水后喷淋液的pH满足要求。In this embodiment, the flue gas to be treated enters the spray tower through the flue gas inlet 503 on the spray tower body 5 and then turns upward, and in the spray area 502, it contacts the slurry sprayed down by the spray pipe 504 countercurrently. Greatly improved the removal effect of SO ₂ in the flue gas. In the spray area, SO ₂ dissolves into the liquid phase and reacts with the absorbent in the spray liquid to generate +quaternary sulfur (NH ₄ ) ₂ SO ₃ and NH ₄ HSO ₃ , and the flue gas from which SO ₂ has been removed continues to be washed upwards and treated with water. In the demisting process of the mist eliminator 505, the net flue gas finally obtained is discharged through the net flue gas outlet 506 at the top of the tower, and the slurry that has absorbed SO ₂ falls into the slurry pool 501 at the bottom of the spray tower. Through the air distributor 2 at the bottom of the slurry pool 501, oxygen is continuously introduced into the slurry pool 501 to oxidize +4-valent sulfur (NH ₄ ) ₂ SO ₃ and NH ₄ HSO ₃ into stable +6-valent sulfur (NH ₄ ) ₂ SO ₄ . During operation, on the one hand, the part of the slurry in the slurry pool 501 is continuously discharged from the slurry outlet by the slurry extraction pump 3, and the subsequent crystallization treatment is carried out, so that the ion concentration in the slurry pool 501 can be maintained constant, and the slurry pool 501 The oxidation rate of +quaternary sulfur (NH ₄ ) ₂ SO ₃ and NH ₄ HSO ₃ can be kept constant. On the other hand, the slurry in the slurry pool 501 is pumped by the circulation pump 4 and sent to the spray pipe 504 for recycling, thereby saving resources. The circulation pipeline connected with the inlet of the circulation pump 4 is also connected with the ammonia water inlet pipe 6, so that the ammonia water can be constantly replenished in the spray liquid to keep the spray liquid to SO _The absorption capacity can be measured by the slurry in the slurry pool 501 pH to adjust the supplementary amount of ammoniacal liquor in the ammoniacal liquor inlet pipe 6, so that the pH of the spray liquid after supplementing the ammoniacal liquor meets the requirements.

如图3所示，本实施例的氨法脱硫吸收产物+4价硫氧化系统的优化调控方法，其具体步骤为：As shown in Figure 3, the optimization and control method of the ammonia desulfurization absorption product + tetravalent sulfur oxidation system in this embodiment, the specific steps are:

步骤一、确定如下模型参数：氨法脱硫系统喷淋塔的D_R、G、F、Q，以及喷淋塔底部浆液池501内浆液的pH、C_S、V、t_r、μ_L和σ_L。Step 1. Determine the following model parameters: D _R , G, F, Q, and the pH, C _S , V, t _r , μ _L and σ _L of the slurry in the slurry pool 501 at the bottom of the spray tower.

其中，D_R为氨法脱硫系统喷淋塔的直径，通过测量直接获得，单位为m；G为由烟气进口503进入喷淋塔内的待处理烟气的烟气流率，通过烟气在线监测系统测得，单位为m³·s^-1；和分别为喷淋塔烟气进口503和净烟气出口506烟气中SO₂的浓度，由烟气在线监测系统测得，单位为mg·m^-3；F为喷淋塔内的液气比，为系统运行的设定值，单位为L·m^-3；Q为喷淋塔浆液池501内的氧化空气量，其值为理论空气量Q₀的1～4倍，其中，理论氧化空气量单位为m³·s^-1；pH为浆液池501内浆液的pH值；C_S为浆液池501内浆液的总硫浓度，为+4价硫浓度和+6价硫浓度之和，其单位为mol·L^-1；V为浆液池501内浆液的体积，通过调整浆液池501内浆液的停留时间t_r进行控制，V＝60t_rL_in，单位为m³，该式中的L_in为通过喷淋管504流进浆液池501的浆液流率，单位为m³·s^-1，通过L_in＝F×G/1000m³·s^-1进行计算；浆液的粘度μ_L和表面张力σ_L分别利用粘度计和表面张力仪测得，其单位分别为Pa·s和N·m^-1；Among them, D _R is the diameter of the spray tower of the ammonia desulfurization system, which is directly obtained by measurement, and the unit is m; Measured by the online monitoring system, the unit is m ³ ·s ^-1 ; and are the concentration of SO ₂ in the flue gas at the flue gas inlet 503 of the spray tower and the flue gas at the net flue gas outlet 506, measured by the flue gas online monitoring system, and the unit is mg m ^-3 ; F is the liquid-gas ratio in the spray tower , is the setting value of the system operation, the unit is L·m ^-3 ; Q is the amount of oxidizing air in the slurry pool 501 of the spray tower, and its value is 1 to 4 times of the theoretical air amount Q ₀ , where the theoretical oxidizing air quantity The unit is m ³ ·s ^-1 ; pH is the pH value of the slurry in the slurry tank 501; C _S is the total sulfur concentration of the slurry in the slurry tank 501, which is the concentration of +4-valent sulfur and +6 valent sulfur concentration The sum, whose unit is mol·L ^-1 ; V is the volume of the slurry in the slurry pool 501, which is controlled by adjusting the residence time t _r of the slurry in the slurry pool 501, V=60t _r L _in , the unit is m ³ , the In the formula, L _in is the flow rate of the slurry flowing into the slurry tank 501 through the spray pipe 504, and the unit is m ³ ·s ^-1 , calculated by _Lin = F×G/1000m ³ ·s ^-1 ; the viscosity of the slurry μ _L and surface tension σ _L were measured by viscometer and surface tension meter respectively, and the units are Pa·s and N·m ^-1 respectively;

本实施例中，D_R为8.6m，t_r为17.62min，G为116.9m³·s^-1，为1556mg·m^-3，为37mg·m^-3，F为3.5L·m^-3，C_s为2.2mol·L^-1，pH为5.2，Q为0.16m³·s^-1，μ_L为0.5494Pa·s，表面张力σ_L为67.77N·m^-1，根据V＝60t_rL_in可计算出浆液池501内浆液体积V为432.55m³。In this example, D _R is 8.6m, t _r is 17.62min, G is 116.9m ³ ·s ^-1 , is 1556mg·m ^-3 , is 37mg·m ^-3 , F is 3.5L·m ^-3 , C _s is 2.2mol·L ^-1 , pH is 5.2, Q is 0.16m ³ ·s ^-1 , _μL is 0.5494Pa·s, surface tension σ _L is _67.77N ·m ^-1 , according to V=60t _r Lin it can be calculated that the volume V of the slurry in the slurry pool 501 is 432.55m ³ .

步骤二、输入步骤一中的模型参数，并设定C_S中+4价硫和+6价硫的初始浓度且满足本实施例中利用+4价硫的氧化率模型计算浆液池501内+4价硫的氧化率该+4价硫的氧化率模型具体如下：Step 2: Input the model parameters in Step 1, and set the initial concentrations of +4-valent _sulfur and +6-valent sulfur in CS and satisfied In this example Calculating the oxidation rate of +4-valent sulfur in the slurry pool 501 by using the oxidation rate model of +4-valent sulfur The oxidation rate model of the +4-valent sulfur is as follows:

式(1)中的为喷淋塔喷淋区502吸收的SO₂的摩尔流率，单位为mol·s^-1，其通过式(2)进行计算：In formula (1) is the molar flow rate of SO2 absorbed by the spray zone 502 of the spray tower, and the unit is mol·s ⁻¹ , which is calculated by formula ( ₂ ):

式(1)中的r_(IV)为浆液池501内+4价硫的氧化速率，单位为mol·L^-1·min^-1，其按式(3)进行计算：r _(IV) in the formula (1) is the oxidation rate of +4-valent sulfur in the slurry tank 501, the unit is mol L ^-1 min ^-1 , which is calculated according to the formula (3):

${r r}_{((I I V V))} = = {C C}_{{O o}_{22}}^{* *} / / ((\frac{11}{{k k}_{L L} a a} + + \frac{11}{{k k}_{00} exp exp ((\frac{- - 2.8 2.8 \times \times 1010^{44}}{R R T T}))} \cdot \cdot \frac{11}{1010^{- - 0.39 0.39 p p H h - - 1.14 1.14}} \cdot &Center Dot; \frac{11}{{C C}_{{SO SO}_{33}^{22 - -}}^{- - 0.5 0.5}} \cdot \cdot \frac{11}{- - 44 {C C}_{{S S}^{66 + +}} + + 99})) - - - - - - ((33)),,$

式(3)中，k₀为频率因子，其值为1.44×10⁴；R为理想气体常数，为8.31J·mol^-1·K^-1；T为喷淋塔内温度，为323.15K；为浆液池501内气液界面处氧的平衡浓度，单位为mol·L^-1，其通过式(4)进行计算：In formula (3), k ₀ is the frequency factor, and its value is 1.44×10 ⁴ ; R is the ideal gas constant, which is 8.31J·mol ^-1 ·K ^-1 ; T is the temperature inside the spray tower, which is 323.15K; is the equilibrium concentration of oxygen at the gas-liquid interface in the slurry tank 501, the unit is mol·L ^-1 , which is calculated by formula (4):

${C C}_{{O o}_{22}}^{* *} = = {Hp HP}_{{O o}_{22}}^{* *} - - - - - - ((44)),,$

式(4)中，为浆液池501内气液界面处O₂的平衡分压，单位为Pa，本实施例中为2.13×10⁴Pa；H为O₂在浆液池501内浆液中的溶解度系数，单位为mol·m^-3·Pa^-1，H按式(5)进行计算：In formula (4), Be the equilibrium partial pressure of O at the gas _- liquid interface place in the slurry pool 501, the unit is Pa, in the present embodiment is 2.13×10 ⁴ Pa; H is the solubility coefficient of O ₂ in the slurry in the slurry tank 501, and the unit is mol·m ^-3 ·Pa ^-1 , and H is calculated according to formula (5):

式(5)中，H⁰为O₂在水中的溶解度系数，其值为9.45×10^-6mol·m^-3·Pa^-1；h_i为浆液池501内电解质引起的O₂溶解度降低系数，单位为m³·kion^-1；I_i为浆液池501内电解质中各离子的离子强度，单位为kion·m^-3。在氨法脱硫工艺中控制的pH值范围内，浆液中H₂SO₃和NH₃·H₂O的浓度低，可以忽略不计，浆液中的电解质是指NH₄HSO₃、(NH₄)₂SO₃和(NH₄)₂SO₄；h_i和I_i分别通过式(6)和式(7)进行计算：In formula (5), H ⁰ is the solubility coefficient of O ₂ in water, and its value is 9.45×10 ^-6 mol·m ^-3 ·Pa ^-1 ; h _i is the solubility reduction coefficient of O ₂ caused by the electrolyte in the slurry pool 501 , the unit is m ³ ·kion ^-1 ; I _i is the ionic strength of each ion in the electrolyte in the slurry pool 501 , the unit is kion·m ^-3 . Within the pH range controlled in the ammonia desulfurization process, the concentration of H ₂ SO ₃ and NH ₃ ·H ₂ O in the slurry is low and negligible, and the electrolyte in the slurry refers to NH ₄ HSO ₃ , (NH ₄ ) ₂ SO ₃ and (NH ₄ ) ₂ SO ₄ ; h _i and I _i are calculated by formula (6) and formula (7):

h_i＝h⁺+h^-+h_G(6)，h _i =h ⁺ +h ^- +h _G (6),

式(6)中，浆液池501内电解质NH₄HSO₃、(NH₄)₂SO₃和(NH₄)₂SO₄中正、负离子及被溶解的氧气引起的数值h⁺、h^-和h_G如表2所示，式(7)中C_i为浆液池501内电解质中各离子的浓度，Z_i为各离子的价数。In formula (6), the values h ⁺ , h ^- and h _G caused by positive and negative ions and dissolved oxygen in the electrolyte NH ₄ HSO ₃ , (NH ₄ ) ₂ SO ₃ and (NH ₄ ) ₂ SO ₄ in the slurry tank 501 As shown in Table 2, C _i in the formula (7) is the concentration of each ion in the electrolyte in the slurry tank 501 , and Z _i is the valence of each ion.

表2实施例1公式(6)中各离子的比例常数(h⁺,h^-andh_G)The proportionality constant (h ⁺ , h ^- andh _G ) of each ion in the formula (6) of the embodiment 1 of table 2

式(9)中，δ₁和δ₂分别为和的分布系数，其中，In formula (9), δ ₁ and δ ₂ are respectively and The distribution coefficient of , where,

式(10)和(11)中，K_a1和K_a2分别为平衡反应和的反应平衡常数，其中，lgK_a1＝853/T-4.74，lgK_a2＝621.9/T-9.278；[H⁺]为浆液池(501)内浆液中氢离子的活性浓度，通过pH值计算得到。In formulas (10) and (11), K _a1 and K _a2 are equilibrium reactions respectively and The reaction equilibrium constant, wherein, lgK _a1 =853/T-4.74, lgK _a2 =621.9/T-9.278; [H ⁺ ] is the active concentration of hydrogen ions in the slurry in the slurry pool (501), calculated by pH value.

式(12)中，α为浆液池内浆液中溶剂的缔合因子，值为2.6；M_B为浆液池内浆液中溶剂的摩尔质量，单位为g·mol^-1，本实施例中M_B为18g·mol^-1；V_A为氧分子的扩散体积，单位为cm³·mol^-1，本实施例中为16.6cm³·mol^-1。In the formula (12), α is the association factor of the solvent in the slurry in the slurry tank, and its value is 2.6; M _B is the molar mass of the solvent in the slurry in the slurry tank, and the unit is g mol ^-1 , and M _B in this embodiment is 18g ·mol ⁻¹ ; V _A is the diffusion volume of oxygen molecules, the unit is cm ³ ·mol ⁻¹ , which is 16.6 cm ³ ·mol ⁻¹ in this embodiment.

$a a = = \frac{66 {ϵ ϵ}_{G G}}{{d d}_{V V S S}} - - - - - - ((1515)),,$

将各参数代入式(1)～(17)，联立式(1)～(17)计算出浆液池501内+4价硫的氧化率为1.1597。Substituting each parameter into formulas (1)-(17), the simultaneous formulas (1)-(17) calculate the oxidation rate of +4-valent sulfur in the slurry pool 501 is 1.1597.

步骤三、将步骤二中计算得到的+4价硫的氧化率和带入如下判别式进行检验，判别式不成立：Step 3, the oxidation rate of +4 valent sulfur calculated in step 2 and Bring in the following discriminant for testing, and the discriminant does not hold:

$| | \frac{{r r}_{((I I V V))} V V}{{M m}_{{SO SO}_{22}}} - - \frac{{C C}_{{S S}^{66 + +}}}{{C C}_{s the s}} | | \leq \leq 0.001 0.001,,$

返回至步骤二中调整和的值，若则增大并减小若则减小并增大重新计算r_(IV)V直至上式成立，最后输出+4价硫的氧化率为96％。Return to step 2 to adjust and value, if increase and reduce like then decrease and increase Recalculate r _(IV) V until the above formula is established, and finally output the oxidation rate of +4-valent sulfur 96%.

步骤四、将步骤三中输出的+4价硫氧化率与实际工程中的目标设定值进行比较，若模型计算值低于目标设定值，则返回至步骤二中按如下方法调整参数pH、Q和C_S中的一个或多个，并重新进行计算，直到步骤三中输出的+4价硫氧化率满足工程要求：降低浆液池501内浆液的pH，步长为0.1；增大氧化空气量Q，步长为0.5；降低浆液池501内浆液的总硫浓度C_S，步长为0.1，C_S的降低通过增大由浆液采出泵3采出的浆液流率L_out来实现。其中，在调整以上各工艺参数时，应在以下调整范围内进行调整：浆液池501内浆液的pH为5.0～6.0，C_s为1.9～2.3mol/L，实际氧化空气量Q与理论氧化空气量Q₀之比m的范围为1～4。本实施例中，工程中要求+4价硫的氧化率不低于98％，保持第一步其它参数不变，调节pH为5.0，继续执行第二步和第三步，计算得到+4价硫的氧化率为98.16％。Step 4, the +4 valent sulfur oxidation rate output in step 3 Compared with the target set value in the actual project, if the model calculated value Lower than the target setting value, then return to step two to adjust one or more of the parameters pH, Q and C _S as follows, and recalculate until the +4-valent sulfur oxidation rate output in step three Meet the engineering requirements: reduce the pH of the slurry in the slurry tank 501 with a step size of 0.1; increase the amount of oxidizing air Q with a step size of 0.5; reduce the total sulfur concentration C _S of the slurry in the slurry tank 501 with a step size of 0.1, C _S The reduction of is achieved by increasing the slurry flow rate L _out produced by the slurry production pump 3 . Among them, when adjusting the above process parameters, it should be adjusted within the following adjustment range: the pH of the slurry in the slurry tank 501 is 5.0-6.0, the C _s is 1.9-2.3mol/L, the actual amount of oxidizing air Q and the theoretical amount of oxidizing air The ratio m of the quantity Q ₀ ranges from 1 to 4. In this example, it is required in the project that the oxidation rate of +4 valent sulfur is not lower than 98%. Keep the other parameters of the first step unchanged, adjust the pH to 5.0, continue to execute the second and third steps, and calculate the +4 valence The oxidation rate of sulfur is 98.16%.

在使用本发明中的氧化率模型来指导实际工程中氧化系统的设计和运行时，先根据实际工程中喷淋塔脱硫系统的固有属性，如喷淋塔直径D_R、进入喷淋塔内的待处理烟气的烟气流率G和喷淋塔烟气进口503烟气中SO₂的浓度等，并结合工程中对氨法脱硫吸收产物+4价硫氧化率的目标设定值，先给定一初始pH值、氧化空气量Q以及C_S中+4价硫和+6价硫的初始浓度将以上初始值代入本发明中的氧化率模型来计算氧化率的数值，并将计算得到的氧化率数值与设定的初始值代入中进行检验，若该判别式不成立，则返回步骤二中调整C_S中和的值，直至上述判别式成立，输出此时的氧化率数值/C_S，并将其与工程中的目标设定值进行比较，若其不满足目标设定值，则通过浆液池内浆液的pH值、氧化空气量Q和C_S中的一个或多个，并重新计算，直至输出的氧化率满足工程中的目标设定值。When using the oxidation rate model in the present invention to guide the design and operation of the oxidation system in the actual project, firstly, according to the inherent attributes of the spray tower desulfurization system in the actual project, such as the diameter of the spray tower _DR , the amount of water entering the spray tower _The flue gas flow rate G of the flue gas to be treated and the concentration of SO2 in the flue gas at the flue gas inlet 503 of the spray tower etc., combined with the target setting value of the +4-valent sulfur oxidation rate of the ammonia desulfurization absorption product in the project, an initial pH value, the amount of oxidizing air Q and the +4-valent sulfur and +6-valent sulfur in C _S are given. The initial concentration Substitute the above initial values into the oxidation rate model in the present invention to calculate the oxidation rate value, and the calculated oxidation rate Initial value and setting value substitution In the test, if the discriminant is not established, then return to step 2 to adjust C _S and value until the above discriminant formula is established, output the value of the oxidation rate at this time /C _S , and compare it with the target setting value in the project, if it does not meet the target setting value, one or more of the pH value of the slurry in the slurry tank, the amount of oxidizing air Q and C _S , And recalculate until the output oxidation rate meets the target setting value in the project.

值得说明的是，发明人(贾勇，环境科学学报，2014，34(8)：1～7)于2010年公开了一篇关于氨法脱硫工艺S(IV)氧化动力学模型研究的文献，在上述文献中发明人基于氨法烟气脱硫工艺的特点，在间歇式鼓泡反应装置中对副产物+4价硫的氧化动力学过程进行了实验研究，研究中结合不同条件下的气含率、液相氧传质系数方程，仅从理论上推导出了+4价硫氧化速率的表达式，但该+4价硫氧化速率的表达式并不能用于指导真实工程实践的运行，即不能通过该氧化速率的表达式来指导优化氨法脱硫吸收产物+4价硫氧化系统的设计和运行，这也造成了困扰发明人较长时间的难题。而本发明中的氨法脱硫吸收产物+4价硫的氧化率模型是发明人继续通过大量的实践研究，结合实际工程中氨法脱硫吸收产物+4价硫氧化系统的真实情况研究出来的，本发明中的+4价硫的氧化率模型，能够直接用于指导真实工程中氨法脱硫吸收产物+4价硫氧化系统的设计和运行，使氨法脱硫喷淋塔浆液池(连续流鼓泡氧化反应器)内+4价硫的氧化率能够满足工程要求。It is worth noting that the inventor (Jia Yong, Journal of Environmental Science, 2014, 34(8): 1-7) published a document on the study of the oxidation kinetic model of S(IV) in the ammonia desulfurization process in 2010. In the above literature, based on the characteristics of the ammonia-based flue gas desulfurization process, the inventor conducted an experimental study on the oxidation kinetics of the by-product + 4-valent sulfur in a batch-type bubbling reaction device. rate, liquid-phase oxygen mass transfer coefficient equation, only theoretically deduced the expression of the +4-valent sulfur oxidation rate, but the expression of the +4-valent sulfur oxidation rate cannot be used to guide the operation of real engineering practice, namely The expression of the oxidation rate cannot be used to guide the optimization of the design and operation of the ammonia desulfurization absorption product + 4-valent sulfur oxidation system, which has also caused problems that have plagued the inventors for a long time. The oxidation rate model of the ammonia desulfurization absorption product+quaternary sulfur oxidation rate model in the present invention is researched by the inventor through a large number of practical researches, combined with the real situation of the ammonia desulfurization absorption product+quaternary sulfur oxidation system in actual projects. The oxidation rate model of +4 valent sulfur among the present invention can be directly used in the design and the operation of guiding ammonia desulfurization absorption product+4 valent sulfur oxidation system in the real project, make ammonia desulfurization spray tower slurry pool (continuous flow drum The oxidation rate of +4-valent sulfur in the bubble oxidation reactor) can meet the engineering requirements.

实施例2：Example 2:

本实施例的一种氨法脱硫吸收产物+4价硫氧化系统同实施例1。An ammonia desulfurization absorption product + tetravalent sulfur oxidation system in this embodiment is the same as that in Embodiment 1.

本实施例的上述氨法脱硫吸收产物+4价硫氧化系统的优化调控方法，其具体步骤为：The method for optimizing and controlling the above-mentioned ammonia desulfurization absorption product + 4-valent sulfur oxidation system in this embodiment, the specific steps are:

其中，上述参数中D_R为8.6m，t_r为17.62min，G为116.9m³·s^-1，为1556mg·m^-3，为37mg·m^-3，F为3.5，C_s为2.2mol·L^-1，pH为5.4，Q为0.16m³·s^-1，μ_L为0.5494Pa·s，表面张力σ_L为67.77N·m^-1，根据V＝60t_rL_in，计算出浆液池体浆液体积V为432.55m³。Among the above parameters, D _R is 8.6m, t _r is 17.62min, G is 116.9m ³ ·s ^-1 , is 1556mg·m ^-3 , is 37mg·m ^-3 , F is 3.5, C _s is 2.2mol·L ^-1 , pH is 5.4, Q is 0.16m ³ ·s ^-1 , _μL is 0.5494Pa·s, surface tension σ _L is 67.77N ·m ^-1 , according to V=60t _r L _in , calculate the volume V of the slurry tank body as 432.55m ³ .

${r r}_{((I I V V))} = = {C C}_{{O o}_{22}}^{* *} / / ((\frac{11}{{k k}_{L L} a a} + + \frac{11}{{k k}_{00} exp exp ((\frac{- - 2.8 2.8 \times \times 1010^{44}}{R R T T}))} \cdot \cdot \frac{11}{1010^{- - 0.39 0.39 p p H h - - 1.14 1.14}} \cdot \cdot \frac{11}{{C C}_{{SO SO}_{33}^{22 - -}}^{- - 0.5 0.5}} \cdot \cdot \frac{11}{- - 44 {C C}_{{S S}^{66 + +}} + + 99})) - - - - - - ((33)),,$

${C C}_{{O o}_{22}}^{* *} = = {Hp HP}_{{O o}_{22}}^{* *} - - - - - - ((44)),,$

h_i＝h⁺+h^-+h_G(6)，h _i =h ⁺ +h ^- +h _G (6),

式(6)中，浆液池501内电解质NH₄HSO₃、(NH₄)₂SO₃和(NH₄)₂SO₄引起的O₂溶解度降低系数h_i同实施例1，式(7)中C_i为浆液池501内电解质中各离子的浓度，Z_i为各离子的价数。In formula (6), the O ₂ solubility reduction coefficient h _i caused by the electrolytes NH ₄ HSO ₃ , (NH ₄ ) ₂ SO ₃ and (NH ₄ ) ₂ SO ₄ in the slurry tank 501 is the same as in Example 1, in formula (7). C _i is the concentration of each ion in the electrolyte in the slurry pool 501 , and Z _i is the valence of each ion.

式(8)中D_O2和d_vs分别为氧在浆液池液相中的扩散系数和浆液池液相中气泡的平均直径，其单位分别为m²·s^-1和m，和d_vs分别按式(12)、(13)进行计算：In formula (8), D _O2 and d _vs are respectively the diffusion coefficient of oxygen in the liquid phase of the slurry pool and the average diameter of bubbles in the liquid phase of the slurry pool, and their units are m ² ·s ^-1 and m, respectively, and d _vs are calculated according to equations (12) and (13) respectively:

$a a = = \frac{66 {ϵ ϵ}_{G G}}{{d d}_{V V S S}} - - - - - - ((1515)),,$

将各参数代入式(1)～(17)，联立式(1)～(17)计算出浆液池501内+4价硫的氧化率为0.9234。Substituting each parameter into formulas (1)-(17), the simultaneous formulas (1)-(17) calculate the oxidation rate of +4-valent sulfur in the slurry pool 501 is 0.9234.

返回至步骤二中调整和的值，若则增大并减小若则减小并增大重新计算r_(IV)V直至上式成立，最后输出+4价硫的氧化率为91.35％。Return to step 2 to adjust and value, if increase and reduce like then decrease and increase Recalculate r _(IV) V until the above formula is established, and finally output the oxidation rate of +4-valent sulfur is 91.35%.

步骤四、将步骤三中输出的+4价硫氧化率与实际工程中的目标设定值进行比较，若步骤三中计算出来的+4价硫氧化率相比工程要求的氧化率低，则返回第二步并调整参数pH、Q和C_S中的一个或多个，重新进行计算，直到步骤三中输出的+4价硫氧化率满足工程要求，本实施例中参数的调整方法同实施例1。Step 4, the +4 valent sulfur oxidation rate output in step 3 Compared with the target setting value in the actual project, if the +4-valent sulfur oxidation rate calculated in step 3 If the oxidation rate is lower than that required by the project, return to the second step and adjust one or more of the parameters pH, Q and CS, and recalculate until the +4-valent _sulfur oxidation rate output in step three To meet the engineering requirements, the parameter adjustment method in this embodiment is the same as that in Embodiment 1.

实施例3：Example 3:

本实施例的上述氨法脱硫吸收产物+4价硫氧化系统的优化调控方法，其具体步骤与实施例1相近，其不同之处在于：步骤一中的C_s为2.0mol·L^-1，pH为5.4，其他参数同实施例1；步骤二中计算得出的为1.4643，步骤三中调整后最后输出的+4价硫氧化率为99.80％。The specific steps of the method for optimizing and controlling the above-mentioned ammonia-based desulfurization absorption product + tetravalent sulfur oxidation system in this example are similar to those in Example 1, except that the C _s in step 1 is 2.0 mol·L ^-1 , pH is 5.4, and other parameters are with embodiment 1; Calculated in step 2 is 1.4643, the final output +4-valent sulfur oxidation rate after adjustment in step 3 is 99.80%.

若第三步中计算出来的+4价硫氧化率相比工程要求的氧化率低，则返回第二步并按如下方法调整参数pH、Q和C_S中的一个或多个，重新进行计算，直到第三步输出的+4价硫氧化率满足工程要求，方法同实施例1。If the +4-valent sulfur oxidation rate calculated in the third step If the oxidation rate is lower than that required by the project, return to the second step and adjust one or more of the parameters pH, Q, and C _S as follows, and recalculate until the +4-valent sulfur oxidation rate output in the third step Satisfy engineering requirement, method is the same as embodiment 1.

实施例4：Example 4:

本实施例的上述氨法脱硫吸收产物+4价硫氧化系统的优化调控方法，其具体步骤与实施例1相近，其不同之处在于：步骤一中的C_s为2.3mol·L^-1，pH为5.4，其他参数同实施例1；步骤二中计算得出的为0.5521，步骤三中调整后最后输出的+4价硫氧化率为87.51％。The specific steps of the method for optimizing and controlling the above-mentioned ammonia-based desulfurization absorption product + tetravalent sulfur oxidation system in this example are similar to those in Example 1, except that the C _s in step 1 is 2.3mol·L ^-1 , pH is 5.4, and other parameters are with embodiment 1; Calculated in step 2 is 0.5521, the final output +4-valent sulfur oxidation rate after adjustment in step 3 was 87.51%.

实施例5：Example 5:

本实施例的上述氨法脱硫吸收产物+4价硫氧化系统的优化调控方法，其具体步骤与实施例1相近，其不同之处在于：步骤一中的pH为5.4，Q为0.32m³·s^-1，其他参数同实施例1；步骤二中计算得出的为0.9382，步骤三中调整后最后输出的+4价硫氧化率为91.74％％。The specific steps of the method for optimizing and controlling the above-mentioned ammonia-based desulfurization absorption product + tetravalent sulfur oxidation system in this example are similar to those in Example 1, except that the pH in step 1 is 5.4, and Q is 0.32m ³ . s ^-1 , other parameters are the same as in Example 1; calculated in step 2 is 0.9382, the final output +4-valent sulfur oxidation rate after adjustment in step 3 is 91.74%%.

实施例6：Embodiment 6:

本实施例的上述氨法脱硫吸收产物+4价硫氧化系统的优化调控方法，其具体步骤与实施例1相近，其不同之处在于：步骤一中的pH为5.4，Q为0.48m³·s^-1，其他参数同实施例1；步骤二中计算得出的为0.9501，步骤三中调整后最后输出的+4价硫氧化率为91.83％。In this embodiment, the above-mentioned method for optimizing and controlling the ammonia desulfurization absorption product + tetravalent sulfur oxidation system, its specific steps are similar to those in Embodiment 1, the difference is that the pH in step 1 is 5.4, and Q is 0.48m ³ · s ^-1 , other parameters are the same as in Example 1; calculated in step 2 is 0.9501, the final output +4-valent sulfur oxidation rate after adjustment in step 3 was 91.83%.

实施例7：Embodiment 7:

本实施例的上述氨法脱硫吸收产物+4价硫氧化系统的优化调控方法，其具体步骤与实施例1相近，其不同之处在于：步骤一中的t_r为14min，pH为5.4，根据V＝G×F×t_r/(1000×60)，计算出浆液池体浆液体积V为343.68m³；步骤二中计算得出的为0.6755，步骤三中调整后最后输出的+4价硫氧化率为88.85％。The method for optimizing and controlling the above-mentioned ammonia desulfurization absorption product + tetravalent sulfur oxidation system in this embodiment has specific steps similar to those in Example 1, except that the t _r in step 1 is 14 min, and the pH is 5.4, according to V=G×F×t _r /(1000×60), the calculated volume V of the slurry tank is 343.68m ³ ; calculated in step 2 is 0.6755, the final output +4-valent sulfur oxidation rate after adjustment in step 3 was 88.85%.

实施例8：Embodiment 8:

本实施例的上述氨法脱硫吸收产物+4价硫氧化系统的优化调控方法，其具体步骤与实施例1相近，其不同之处在于：步骤一中的t_r为20min，pH为5.4，根据V＝G×F×t_r/(1000×60)，计算出浆液池体浆液体积V为343.68m³；步骤二中计算得出的为0.9419，步骤三中调整后最后输出的+4价硫氧化率为92.22％。The method for optimizing and controlling the above-mentioned ammonia-based desulfurization absorption product + 4-valent sulfur oxidation system in this embodiment has specific steps similar to those in Example 1, except that the t _r in step 1 is 20 min, and the pH is 5.4, according to V=G×F×t _r /(1000×60), the calculated volume V of the slurry tank is 343.68m ³ ; calculated in step 2 is 0.9419, the final output +4-valent sulfur oxidation rate after adjustment in step 3 was 92.22%.

实施例9：Embodiment 9:

为了验证模型的合理性，取样测试某2×150MW锅炉配套建设的氨法脱硫系统浆液池内浆液的pH、和pH采用哈纳HI98128型pH计测量，采用碘量法测定，采用离子色谱测定，浆液中+4价硫的氧化率可以按式进行计算。实验测得浆液池浆液pH约5.3～5.4，C_s约为1.95～2.16mol·L^-1，+4价硫的氧化率约96.2％～99％。In order to verify the rationality of the model, samples were taken to test the pH, and The pH was measured with a Hana HI98128 pH meter. determined by the iodometric method, Determination by ion chromatography, the oxidation rate of +4 valent sulfur in the slurry can be calculated according to the formula Calculation. According to the experiment, the pH of the slurry in the slurry tank is about 5.3-5.4, the C _s is about 1.95-2.16mol·L ^-1 , and the oxidation rate of +4-valent sulfur is about 96.2%-99%.

确定模型参数D_R为8.6m，t_r为17.62min，G为420833m³·h^-1，为1556mg·m^-3，为37mg·m^-3，F为3.5，Q为0.32m³·s^-1，同时将上述参数带入本发明的+4价硫氧化率模型进行计算，模型计算流程如附图3所示。将上述实验测定值与本实施例的模型计算值进行对比，结果如图4所示，图4中，A、B线为±10％的误差线。从图4中可以看出，+4价硫的模型计算值和实验测定值的误差小于10％，模型能够满足工程应用的精度要求。Determine the model parameters DR as 8.6m, _{t r} _as 17.62min, G as 420833m ³ ·h ^-1 , is 1556mg·m ^-3 , is 37mg·m ^-3 , F is 3.5, and Q is 0.32m ³ ·s ^-1 . At the same time, the above parameters are brought into the +4-valent sulfur oxidation rate model of the present invention for calculation. The model calculation flow is shown in Figure 3. The above experimental measured values were compared with the calculated values of the model of this embodiment, and the results are shown in Figure 4. In Figure 4, lines A and B are error bars of ±10%. It can be seen from Figure 4 that the error between the model calculation value and the experimental measurement value of +4-valent sulfur is less than 10%, and the model can meet the accuracy requirements of engineering applications.

以上示意性的对本发明及其实施方式进行了描述，该描述没有限制性，附图中所示的也只是本发明的实施方式之一，实际的结构并不局限于此。所以，如果本领域的普通技术人员受其启示，在不脱离本发明创造宗旨的情况下，不经创造性的设计出与该技术方案相似的结构方式及实施例，均应属于本发明的保护范围。The above schematically describes the present invention and its implementation, which is not restrictive, and what is shown in the drawings is only one of the implementations of the present invention, and the actual structure is not limited thereto. Therefore, if a person of ordinary skill in the art is inspired by it, without departing from the inventive concept of the present invention, without creatively designing a structural mode and embodiment similar to the technical solution, it shall all belong to the protection scope of the present invention .

Claims

1. An ammonia desulfurization absorption product + 4-valent sulfur oxidation system, comprising a spray tower body (5), characterized in that: the spray tower body (5) includes a demisting area, a spray area (502) and slurry tank (501), wherein, a net flue gas outlet (506) is provided on the top of the spray tower body (5), and a demister area below the net flue gas outlet (506) is provided A demister (505) is arranged, and this demister (505) is connected to the process water tank outside the spray tower; a spray pipe (504) is provided on the top of the spray area (502), and the spray A smoke inlet (503) is provided on the side of the tower body corresponding to the lower part of the area (502); an air distributor (2) is provided at the bottom of the slurry pool (501), and the air inlet of the air distributor (2) The pipeline is connected to the oxidation blower (1); the side of the tower body corresponding to the slurry pool (501) is connected to the slurry extraction pump (3) through the production pipeline, and the slurry pool (501) is connected to the spray pipe ( 504) is connected to the water inlet, and a circulation pump (4) is also provided on the circulation pipeline, and the circulation pipeline connected with the inlet of the circulation pump (4) is also connected to the ammonia water inlet pipe (6).

2. A kind of ammonia desulfurization absorption product+quaternary sulfur oxidation system according to claim 1, characterized in that: the pipes connected to the flue gas inlet (503) and the net flue gas outlet (506) are respectively provided with Smoke online monitoring system.

3. An ammonia desulfurization absorption product + 4-valent sulfur oxidation system according to claim 1 or 2, characterized in that: in the slurry pool (501) and connected to the outlet of the circulation pump (4) There are pH meters on the circulation pipelines.

4. A method for optimizing and controlling the ammonia desulfurization absorption product + 4-valent sulfur oxidation system, the steps of which are:

Step 1. Determine the following model parameters: D _R , G, F, Q, and the pH, C _S , V, t _r , μ _L and σ _L of the slurry in the slurry tank (501) at the bottom of the spray tower;

Among them, _DR is the diameter of the spray tower of the ammonia desulfurization system, which is directly obtained by measurement, and the unit is m; G is the flue gas flow rate of the flue gas to be treated entering the spray tower from the flue gas inlet (503), which is obtained by Measured by the flue gas online monitoring system, the unit is m ³ ·s ^-1 ; and are the concentration of SO ₂ in the flue gas at the flue gas inlet (503) and the net flue gas outlet (506) of the spray tower respectively, measured by the flue gas online monitoring system, and the unit is mg m ^-3 ; F is the concentration in the spray tower The liquid-gas ratio is the set value of the system operation, and the unit is L m ^-3 ; Q is the amount of oxidation air in the slurry tank (501) of the spray tower, and its value is 1 to 4 times of the theoretical air amount Q ₀ , the unit is m ³ ·s ^-1 ; pH is the pH value of the slurry in the slurry tank (501); C _S is the total sulfur concentration of the slurry in the slurry tank (501), which is the +4-valent sulfur concentration and +6 valent sulfur concentration The sum, its unit is mol L ^-1 ; V is the volume of the slurry in the slurry pool (501), controlled by adjusting the residence time t _r of the slurry in the slurry pool (501), V=60t _r L _in , the unit is m ³ , Lin _in this formula is the slurry flow rate that flows into the slurry pool (501) through the spray pipe (504), the unit is m ³ ·s ^-1 , through _Lin = F×G/1000m ³ ·s ^-1 is calculated; the viscosity μ _L and surface tension σ _L of the slurry are measured by a viscometer and a surface tension meter respectively, and the units are Pa·s and N·m ^-1 respectively;

Step 2: Input the model parameters in step 1, and set an initial pH value, oxidizing air quantity Q, and the initial concentrations C _S4+ and C _S6 ₊ of +4-valent sulfur and +6-valent sulfur in CS, and satisfy Calculating the oxidation rate of +4-valent sulfur in the slurry pool (501) by using the oxidation rate model of +4-valent sulfur

Step 3, the oxidation rate of +4 valent sulfur calculated in step 2 Enter the following formula for inspection:

| | \frac{{r r}_{((I I V V))} V V}{{M m}_{{SO SO}_{22}}} - - \frac{{C C}_{{S S}^{66 + +}}}{{C C}_{s the s}} | | \leq \leq 0.001 0.001

If the calculated oxidation rate of +4-valent sulfur If the above formula is not satisfied, return to step 2 for adjustment and value, if

r_{(I V)} V / m_{{SO}_{2}} < C_{S^{6 +}} / C_{S},

increase and reduce like

r_{(I V)} V / m_{{SO}_{2}} > C_{S^{6 +}} / C_{S},

then decrease and increase Recalculate r _(IV) V until the above formula is established, and finally output the and the oxidation rate of +4-valent sulfur

Step 4, the +4 valent sulfur oxidation rate output in step 3 Compared with the target set value in the actual project, if the model calculated value Lower than the target setting value, then return to step two to adjust one or more of the parameters pH, Q and C _S as follows, and recalculate until the +4-valent sulfur oxidation rate output in step three Meet engineering requirements:

Reduce the pH of the slurry in the slurry tank (501), with a step size of 0.1; increase the amount of oxidizing air Q, with a step size of 0.5; reduce the total sulfur concentration C _S of the slurry in the slurry tank (501), with a step size of 0.1, C _S The reduction of is achieved by increasing the slurry flow rate L _out produced by the slurry production pump (3).

5. The method for optimizing and regulating the ammonia process desulfurization absorption product+4valent sulfur oxidation system according to claim 4, characterized in that: the oxidation rate of +4valent sulfur in the slurry tank (501) in step 2 is calculated according to the following model :

η η = = {r r}_{((I I V V))} V V / / {M m}_{{SO SO}_{22}} - - - - - - ((11)),,

In formula (1) is the molar flow rate of SO absorbed by the spray tower spray zone (502), the unit is mol·s ⁻¹ , which is calculated by formula ( ₂ ):

{M m}_{{SO SO}_{22}} = = G G \times \times (({C C}_{{SO SO}_{22},, i i n no} - - {C C}_{{SO SO}_{22},, o o u u t t})) / / ((10001000 \times \times 6464)) - - - - - - ((22)),,

r _(IV) in the formula (1) is the oxidation rate of +4-valent sulfur in the slurry pool (501), the unit is mol L ^-1 min ^-1 , which is calculated according to the formula (3):

{r r}_{((I I V V))} = = {C C}_{{O o}_{22}}^{* *} / / ((\frac{11}{{k k}_{L L} a a} + + \frac{11}{{k k}_{00} exp exp ((\frac{- - 2.8 2.8 \times \times 1010^{44}}{R R T T}))} \cdot \cdot \frac{11}{1010^{- - 0.39 0.39 p p H h - - 1.14 1.14}} \cdot \cdot \frac{11}{{C C}_{{SO SO}_{33}^{22 - -}}^{- - 0.5 0.5}} \cdot \cdot \frac{11}{- - 44 {C C}_{{S S}^{66 + +}} + + 99})) - - - - - - ((33)),,

In formula (3), k ₀ is the frequency factor, and its value is 1.44×10 ⁴ ; R is the ideal gas constant, which is 8.31J·mol ^-1 ·K ^-1 ; T is the temperature inside the spray tower, and the unit is K; is the equilibrium concentration of oxygen at the gas-liquid interface in the slurry tank (501), the unit is mol L ^-1 , which is calculated by formula (4):

{C C}_{{O o}_{22}}^{* *} = = {Hp HP}_{{O o}_{22}}^{* *} - - - - - - ((44)),,

In formula (4), is the equilibrium partial pressure of _O2 at the gas-liquid interface in the slurry pool (501), the unit is Pa; H is the solubility coefficient of _O2 in the slurry in the slurry pool (501), and the unit is mol·m ⁻³ ·Pa ⁻¹ , H is calculated according to formula (5):

l l o o g g ((\frac{{H h}^{00}}{H h})) = = {h h}_{11} {I I}_{11} + + {h h}_{22} {I I}_{22} + + ... ... + + {h h}_{i i} {I I}_{i i} + + ... ... - - - - - - ((55)),,

In formula (5), H ⁰ is the solubility coefficient of O ₂ in water; h _i is the solubility reduction coefficient of O ₂ caused by the electrolyte in the slurry pool (501), the unit is m ³ ·kion ^-1 ; I _i is the slurry pool ( 501) The ionic strength of each ion in the inner electrolyte, the unit is kion m ^-3 , h _i and I _i are calculated by formula (6) and formula (7):

h _i =h ⁺ +h ^- +h _G (6),

{I I}_{i i} = = \frac{11}{22} {ΣC ΣC}_{i i} {Z Z}_{i i}^{22} - - - - - - ((77)),,

In formula (6), h ⁺ , h ^- , h _G are values caused by electrolyte positive and negative ions and dissolved oxygen respectively; in formula (7), C _i is the concentration of each ion in the electrolyte in the slurry pool (501), Z _i is the valence of each ion; within the pH range controlled in the ammonia desulfurization process, the concentration of H ₂ SO ₃ and NH ₃ ·H ₂ O in the slurry is low and can be ignored, and the electrolyte in the slurry refers to NH ₄ HSO ₃ , (NH ₄ ) ₂ SO ₃ and (NH ₄ ) ₂ SO ₄ ;

In formula (3), k _L is the mass transfer coefficient of oxygen in the liquid phase, the unit is m·s ^-1 , which is calculated according to formula (8):

{k k}_{L L} = = 0.5 0.5 {g g}^{55 / / 88} {D D.}_{{O o}_{22}}^{11 / / 22} {ρ ρ}_{L L}^{33 / / 88} {σ σ}_{L L}^{- - 33 / / 88} {d d}_{v v s the s}^{11 / / 22} - - - - - - ((88)),,

In the formula (8), ρ _L is the density of the slurry in the slurry tank (501), the unit is kg·m ^-3 , which is calculated by the formula (9):

{ρ ρ}_{L L} = = ((9999 {δ δ}_{11} {C C}_{{S S}^{44 + +}} + + 116116 {δ δ}_{22} {C C}_{{S S}^{44 + +}} + + 132132 {C C}_{{S S}^{66 + +}})) / / 10001000 - - - - - - ((99)),,

In formula (9), δ ₁ and δ ₂ are respectively and The distribution coefficient of , where:

{δ δ}_{11} = = \frac{{K K}_{a a 11} [[{H h}^{+ +}]]}{{[[{H h}^{+ +}]]}^{22} + + {K K}_{a a 11} [[{H h}^{+ +}]] + + {K K}_{a a 11} {K K}_{a a 22}} - - - - - - ((1010)),,

{δ δ}_{22} = = \frac{{K K}_{a a 11} {K K}_{a a 22}}{{[[{H h}^{+ +}]]}^{22} + + {K K}_{a a 11} [[{H h}^{+ +}]] + + {K K}_{a a 11} {K K}_{a a 22}} - - - - - - ((1111)),,

In formulas (10) and (11), K _a1 and K _a2 are equilibrium reactions respectively and [H ⁺ ] is the active concentration of hydrogen ions in the slurry in the slurry pool (501), calculated by the pH value;

In formula (8) and d _vs are respectively the diffusion coefficient of oxygen in the liquid phase of the slurry pool (501) and the average diameter of bubbles in the liquid phase of the slurry pool (501), and the units are m ² ·s ^-1 and m, respectively, and d _vs are calculated according to equations (12) and (13) respectively:

{D D.}_{{O o}_{22}} = = \frac{7.4 7.4 \times \times 1010^{- - 1212} {(({αM αM}_{B B}))}^{0.5 0.5} T T}{{μ μ}_{L L} {V V}_{A A}^{0.6 0.6}} - - - - - - ((1212)),,

{d d}_{v v s the s} = = 2626 {D D.}_{R R} {((\frac{{gD gD}_{R R}^{22}}{{σ σ}_{L L}}))}^{- - 0.5 0.5} {((\frac{{gD gD}_{R R}^{33} {ρ ρ}_{L L}^{22}}{{μ μ}_{L L}^{22}}))}^{- - 0.12 0.12} {((\frac{{u u}_{O o G G}}{\sqrt{{gD gD}_{R R}}}))}^{- - 0.12 0.12} - - - - - - ((1313)),,

In the formula (12), α is the association factor of the solvent in the slurry in the slurry pool (501), and the value is 2.6; M _B is the molar mass of the solvent in the slurry in the slurry pool (501), and the unit is g mol ⁻¹ ; V _A is the diffusion volume of oxygen molecules, the unit is cm ³ ·mol ^-1 ;

In the formula (13), u _OG is the superficial gas velocity of the oxidizing air in the slurry tank (501), the unit is m·s ^-1 , which is calculated according to the formula (14):

{u u}_{O o G G} = = Q Q / / (({πD πD}_{R R}^{22} / / 44)) - - - - - - ((1414)),,

In formula (3), a is the gas-liquid contact interface area in m ² ·m ^-3 , calculated according to formula (15):

a a = = \frac{66 {ϵ ϵ}_{G G}}{{d d}_{V V S S}} - - - - - - ((1515)),,

In formula (15), the gas holdup ε _G in the liquid phase in the slurry pool (501) is calculated as follows:

\frac{{ϵ ϵ}_{G G}}{{((11 - - {ϵ ϵ}_{G G}))}^{44}} = = 0.25 0.25 \times \times ((\frac{{u u}_{O o G G} {μ μ}_{L L}}{{σ σ}_{L L}})) {((\frac{{ρ ρ}_{L L} {σ σ}_{L L}^{33}}{{gμ gμ}_{L L}^{44}}))}^{77 / / 24 twenty four} - - - - - - ((1616)),,

In formula (3), concentration Calculate as follows:

{C C}_{{SO SO}_{33}^{22 - -}} = = {δ δ}_{22} {C C}_{{S S}^{44 + +}} - - - - - - ((1717)),,

Simultaneous formulas (1) to (17) calculate the oxidation rate of +4-valent sulfur in the slurry pool (501)

6. According to claim 4 or 5, the optimization control method of the ammonia desulfurization absorption product + 4-valent _sulfur oxidation system is characterized in that: the parameter range requirements of adjusting parameters pH, Q, CS in step 4 are as follows: slurry pool (501) The pH of the inner slurry is 5.0-6.0, C _s is _1.9-2.3 mol/L, and the ratio m of the actual amount of oxidizing air Q to the theoretical amount of oxidizing air Q0 is in the range of 1-4.