CN105032154B - Ammonia desulphurization absorbent product S4+ oxidation system and optimal regulation and control method - Google Patents

Abstract

The invention discloses an ammonia desulphurization absorbent product S<4+> oxidation system and an optimal regulation and control method, and belongs to the technical field of air pollution control. Model parameters in an ammonia desulphurization system are determined at first; the model parameters are input, an initial pH value, an oxidation air capacity Q and initial concentrations (shown in the description) of S<4+> and S<6+> are set, and the oxidation ratio r(IV)V/MSO2 of S<4+> in a slurry pond is calculated by use of an oxidation ratio model of S<4+>; the oxidation ratio r(IV)V/MSO2 of S<4+> is substituted into |r(IV)V/MSO2-CS<6+>/Cs|<=0.001 for inspection, if the formula is not valid, the values of CS<4+> and CS<6+> are re-calculated till |r(IV)V/MSO2-CS<6+>/Cs|<=0.001 is valid, the obtained oxidation ratio and the set value in the project are compared, the pH value, the oxidation air capacity Q, CS<4+> and CS<6+> in the model are adjusted to ensure that the oxidation ratio of S<4+> can meet the project demand. The oxidation ratio model can provide theoretical reference for the design and the operation of the ammonia desulphurization absorbent product S<4+> oxidation system, and further, the stability and the economical efficiency of the ammonia desulphurization technology are improved.

Description

+ 4 valency sulphur oxidative system of ammonia process of desulfurization absorption product and its optimization regulating method

Technical field

The invention belongs to technical field of atmospheric pollution control, more particularly, it relates to a kind of ammonia process of desulfurization absorption product+4 Valency sulphur oxidative system and its optimization regulating method.

Background technology

Sulfur dioxide (SO₂) it is the Air Pollutants for being only second to particulate matter at present in China's harm, but it is simultaneously It is a kind of resource.With the appearance of national new standard, Sulfur Dioxide Emission Allowances are 400mg/Nm³, this is made for much old With a kind of economy is selected for coal-burning boiler producer, the tail gas treatment process of high treating effect is that manufacturer is most urgent Task.

The desulfurization method of limestone-gypsum technique dominated at present, as desulfurizer invests larger, medium or small hot power station is difficult to hold Receive, and operating cost is higher, desulfurizing byproduct gypsum is processed using method of abandoning or landfill method, easily causes secondary pollution, while The great amount of carbon dioxide produced in sweetening process is a kind of greenhouse gases, so as to limit the application of the method.With calcium method desulfurization work Skill is compared, and the ammonia process of desulfurization is with the higher ammonia (NH of chemical reactivity₃) SO in flue gas is absorbed for desulfurizing agent₂, system dynamic disappears Consumption is low, in efficient removal SO₂While, moreover it is possible to the recovery of Sulphur ressource, and the discharge without waste water and waste residue are realized, is met China and is sent out Exhibition recycling economy, the Policy Demand for creating conservation-minded society, therefore which becomes solution SO₂Directly discharge causes Air seriously polluted Effective way, and the ammonia process of desulfurization is progressively widely applied in the big-and-middle-sized coal-fired flue gas desulfurization project of China, before development Scape is good.But the byproduct of the ammonia process of desulfurization is (NH₄)₂SO₃And NH₄HSO₃, it is heated in atmosphere, direct value Less, ammonium sulfate need to be further oxidized to be recycled.Ammonia process of desulfurization spray column is the core of ammonia method desulfurizing system, existing Generally using directly air is passed through into spray column in technology, so that (NH₄)₂SO₃And NH₄HSO₃+ 6 stable valencys can be oxidized to Sulphur (NH₄)₂SO₄, in right+4 valency sulphur (NH₄)₂SO₃And NH₄HSO₃When carrying out oxidation processes, the key reaction being related to is as follows：

Therefore, it is to realize that the ammonia process of desulfurization is stablized, economy is transported that how efficiently ,+4 valency sulphur are oxidized into+6 valency sulphur by low energy consumption ground Capable basis, so as to attract the concern of numerous researchers and engineers and technicians.

The oxidation of+4 valency sulphur of ammonia process of desulfurization absorption product is mainly by slurry pH value ,+4 valency sulphur concentrations ,+6 valency sulphur concentrations, oxidation The impact of all many conditions such as air capacity and temperature.So far, research thio-oxidizing to+4 valency of ammonia process of desulfurization absorption product is main In terms of concentrating on sulfite oxidation dynamics, mainly have than more typical：(the Chemical Engineering such as Zhou J H Science, 2000,55 (23):5637-5641) certain density O is passed through to above solution in stirred reactor₂, O₂Diffusion There is oxidation reaction into solution and ammonium sulfite, result of study shows that the oxidation rate of ammonium sulfite is in 1 grade to oxygen concentration, Inferior sulfate radical concentration is in -1 grade to which when being less than critical concentration, is in 0.2 grade to which when inferior sulfate radical concentration is higher than critical concentration. Zhao B etc. (Chemical Engineering Science, 2005,60 (3):Single bubble reaction unit pair is set up 863-868) The oxidizing process of ammonium sulfite has carried out experimental study, as a result shows, the oxidation rate of ammonium sulfite is low in inferior sulfate radical concentration It is in 1 grade to which when critical concentration, is in 0 grade to which when inferior sulfate radical concentration is higher than critical concentration, the oxidation speed of ammonium sulfite Rate increases with the increase of solution ph, when pH value is 6～9, impact linearly rule of constant concentration of the pH value to oxidation rate.Although learning Persons achieve some beneficial results in terms of sulfite oxidation research, but due toWithOxidation rate not Individually can measure, not to occupying the majority in+4 valency sulphur of ammonia process of desulfurization absorption product in conventional researchOxidation enter Row is distinguished, and the control of pH value differs larger with actual ammonia process of desulfurization engineering in testing, have ignored acid/base tune pH value cause from The impact of sub- Strength Changes, the oxidizing process mechanism of+4 valency sulphur of ammonia process of desulfurization absorption product are not reasonably annotated.

In Practical Project ,+4 valency sulphur of ammonia process of desulfurization absorption product is often roused in the slurry pool of spray-absorption tower bottom The air oxidation for entering becomes stable ammonium sulfate, and its slurry pool can approximately regard continuous stream continuous stir reactor bubbling reactor as, spray In tower bottom slurry pool, typically in 323.15K or so, the oxidation of+4 valency sulphur is dense with total sulfur in slurry pH value, slurries for the temperature of slurries The factors such as degree, the time of staying of the oxidation air amount with slurries in slurry pool are relevant.Oxygenation efficiency is to weigh+4 valency sulphur oxidation effectivenesses Leading indicator, the thio-oxidizing process conditions of+4 valency of experience control ammonia process of desulfurization absorption product are depended in current engineering, Easily cause energy waste or+4 valency sulfur oxidation rates be low, and stablizing for+4 valency sulfur oxidation rates in slurry tank can not be maintained, And then cause that system operation is unstable, the low problem of ammonium sulfate byproduct recovery rate.

Therefore, work out one kind and can realize+4 valency sulfur highly effective of ammonia process of desulfurization absorption product, stable oxidation, and can be used in true The system of real engineering practice, and can be used in directly instructing the model of the design and operation that optimize the oxidative system that just there is weight The theory significance wanted and engineering application value.

The content of the invention

1. invention technical problem to be solved

It is an object of the invention to overcome the ammonia process of desulfurization spray column used in current engineering realize that desulfurization absorbs + 4 valency sulphur of product is stable, efficient oxidation, and the control of its oxidation process conditions depends on experience, easily causes energy wave Take, the deficiency that system operation is unstable and ammonium sulfate byproduct yield is low, there is provided a kind of+4 valency sulphur of ammonia process of desulfurization absorption product Oxidative system and its optimization regulating method.By using the oxygenation efficiency model of+4 valency sulphur in the present invention, can be used in directly guidance The optimization design of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product and operation in the present invention, such that it is able to absorb the ammonia process of desulfurization The oxygenation efficiency of+4 valency sulphur of product meets industrial requirements.

2. technical scheme

To reach above-mentioned purpose, the technical scheme that the present invention is provided is：

First, a kind of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the present invention, including spray column body, the spray Tower body interior includes from top to bottom successively except fog-zone, spraying zone and slurry pool, wherein, at the top of described spray column body Neat stress outlet is provided with, the technique except fog-zone is provided with demister, outside the demister and spray column below neat stress is exported Water tank is connected；Shower is provided with the top of described spraying zone, and flue gas is provided with the corresponding tower body side in spraying zone bottom Import；Air sparger is provided with the bottom of described slurry pool, the air inlet duct and oxidation fan of the air sparger It is connected；Produce pump and be connected by producing pipeline and slurries in the corresponding tower body side of slurry pool, and the slurry pool is by circulation pipe Road is connected with the water inlet of shower, and circulating pump is additionally provided with circulating line, the circulating line with the inlet communication of circulating pump Also it is connected with ammoniacal liquor inlet tube.

Further, being respectively equipped with flue gas on-line monitoring on the pipeline being connected with gas approach and neat stress outlet is System.

Further, pH is equipped with the circulating line being connected in described slurry pool and with circulating-pump outlet Meter.

Second, the optimization regulating method of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the present invention, its step is：

Step one, it is defined below model parameter：The D of ammonia method desulfurizing system spray column_R、G、F、Q, with And in spray column bottom slurry pond slurries pH, C_S、V、t_r、μ_LAnd σ_L；

Wherein, D_RFor the diameter of ammonia method desulfurizing system spray column, directly obtained by measurement, unit is m；G is by flue gas The flue gas flow rate of the pending flue gas that import is entered in spray column, is measured by smoke on-line monitoring system, and unit is m³·s^-1；WithRespectively SO in spray column gas approach and neat stress exiting flue gas₂Concentration, by smoke on-line monitoring system Measure, unit is mg m^-3；F is the liquid-gas ratio in spray column, is the setting value of system operation, and unit is L m^-3；Q is spray Oxidation air amount in tower slurry pool, its value are theoretical air requirement Q₀1～4 times, unit is m³·s^-1；PH is slurry pool entoplasm The pH value of liquid；C_SFor the total sulfur concentration of slurries in slurry pool, it is+4 valency sulphur concentrationsWith+6 valency sulphur concentrationsSum, its unit For mol L^-1；V is the volume of slurries in slurry pool, by the time of staying t for adjusting slurries in slurry pool_rIt is controlled, V= 60t_rL_in, unit is m³, the L in the formula_inIt is the slurry flow rate for entering slurry pool by shower stream, unit is m³·s^-1, pass through L_in=F × G/1000m³·s^-1It is calculated；The viscosity, mu of slurries_LWith surface tension σ_LIt is utilized respectively viscosimeter and surface tension Instrument is measured, and its unit is respectively Pa s and N m^-1；

Model parameter in step 2, input step one, and set an initial pH value, oxidation air amount Q and C_SIn+4 The initial concentration of valency sulphur and+6 valency sulphurAnd meetCalculated using the oxygenation efficiency model of+4 valency sulphur The oxygenation efficiency of+4 valency sulphur in slurry pool

Step 3, by the oxygenation efficiency of calculated+4 valency sulphur in step 2Bring following formula into test：

If the oxygenation efficiency of calculated+4 valency sulphurAbove formula is unsatisfactory for, is adjusted in being back to step 2 WithValue, ifThen increaseAnd reduceIfThen reduceAnd increaseRecalculate r_(IV)V is until above formula establishment, finally exportsWith the oxygenation efficiency of+4 valency sulphur

Step 4, by+4 valency sulfur oxidation rates exported in step 3Carry out with the target set point in Practical Project Relatively, if model calculation valueLess than target set point, then adjusting parameter pH, Q as follows is back in step 2 And C_SIn one or more, and re-start calculating ,+4 valency sulfur oxidation rates exported in step 3Meet work Range request：

The pH of slurries in slurry pool is reduced, step-length is 0.1；Increase oxidation air amount Q, step-length is 0.5；Reduce in slurry pool The total sulfur concentration C of slurries_S, step-length is 0.1, C_SReduction by increase by slurries produce pump extraction slurry flow rate L_outCome real It is existing.

Further, in step 2 in slurry pool the oxygenation efficiency of+4 valency sulphur by being calculated with drag：

In formula (1)For the SO that spray column spraying zone absorbs₂Molar flow rate, unit be mol s^-1, which passes through formula (2) calculated：

R in formula (1)_(IV)For the oxidation rate of+4 valency sulphur in slurry pool, unit is mol L^-1·min^-1, which presses formula (3) Calculated：

In formula (3), k₀For frequency factor, its value is 1.44 × 10⁴；R is ideal gas constant, is 8.31J mol^-1·K^-1；T is temperature in spray column, and unit is K；For the equilibrium concentration of oxygen at gas-liquid interface in slurry pool, unit is mol L^-1, Which passes through formula (4) and is calculated：

In formula (4),For O at gas-liquid interface in slurry pool₂Equilibrium partial pressure, unit is Pa；H is O₂In slurry pool entoplasm Solubility coefficient in liquid, unit are mol m^-3·Pa^-1, H calculated by formula (5)：

In formula (5), H⁰For O₂Solubility coefficient in water；h_iFor the O that slurry pool Inner electrolysis matter causes₂Solubility is reduced Coefficient, unit are m³·kion^-1；I_iThe ionic strength of each ion in liquid pool Inner electrolysis matter, unit are kion m^-3, h_iAnd I_iPoint Not Tong Guo formula (6) and formula (7) calculated：

h_i=h⁺+h^-+h_G(6),

In formula (6), h⁺、h^-、h_GIt is respectively the numerical value that the electrolyte positive and negative ion and dissolved oxygen cause；Formula (7) Middle C_iFor the concentration of each ion of slurry pool Inner electrolysis matter, Z_iFor the valence mumber of each ion；The pH value controlled in ammonia desulfurizing process In the range of, H in slurries₂SO₃And NH₃·H₂The concentration of O is low, is negligible, and the electrolyte in slurries refers to NH₄HSO₃、 (NH₄)₂SO₃(NH₄)₂SO₄；

In formula (3), k_LFor oxygen mass tranfer coefficient in the liquid phase, unit is m s^-1, which is calculated by formula (8)：

In formula (8), ρ_LFor the density of slurries in slurry pool, unit is kg m^-3, which passes through formula (9) and is calculated：

In formula (9), δ₁And δ₂RespectivelyWithBreadth coefficient, wherein：

In formula (10) and (11), K_a1And K_a2Respectively balanced reactionWithReaction equilibrium constant；[H⁺] for hydrionic active concentration in the interior slurries of slurry pool (501), lead to Cross pH value to be calculated；

In formula (8)And d_vsRespectively in diffusion coefficient of the oxygen in slurry pool liquid phase and slurry pool liquid phase, bubble is flat Equal diameter, its unit are respectively m²·s^-1And m,And d_vsCalculated by formula (12), (13) respectively：

In formula (12), α is the associated factors of solvent in slurries in slurry pool, is worth for 2.6；M_BFor molten in slurries in slurry pool The molal weight of agent, unit are g mol^-1；V_AFor the diffusion volume of oxygen molecule, unit is cm³·mol^-1；

In formula (13), u_OGFor the superficial gas velocity of slurry pool internal oxidition air, unit is m s^-1, based on which is carried out by formula (14) Calculate：

In formula (3), a is gas-liquid contact interfacial area, and unit is m²·m^-3, calculated by formula (15)：

Gas holdup ε in formula (15), in slurry pool in liquid phase_GCalculated as the following formula：

In formula (3),ConcentrationCalculated as the following formula：

Simultaneous formula (1)～(17) calculate the oxygenation efficiency of+4 valency sulphur slurry pool Nei

Further, adjusting parameter pH, Q, C in step 4_SParameter area require it is as follows：The pH of slurries in slurry pool For 5.0～6.0, C_sFor 1.9～2.3mol/L, actual oxidation air capacity Q and theoretical oxidation air capacity Q₀Ratio m scope be 1～ 4。

The oxidation of+4 valency sulphur of ammonia process of desulfurization absorption product is carried out in spray column bottom slurry pond, is starched under the conditions of stable operation Liquid pool approximately can regard as continuous stream entirely mix bubbling reactor, in addition, the oxygenation efficiency of+4 valency sulphur mainly with pH value, total sulfur concentration, oxygen Change the factors such as the time of staying of air capacity and slurries in slurry pool relevant.Based on These characteristics, the present invention combines+4 valency sulphur oxygen Change rate equation, set up the thio-oxidizing Mathematical Modeling of+4 valencys in slurry pool.

The oxygenation efficiency formula of interior+4 valency sulphur of slurry pool in the present inventionDerivation it is as follows：

Under limit, the slurry pool in the ammonia process of desulfurization spray column in Fig. 1 can be reduced to model as shown in Figure 2, There is following equilibrium relation in the slurries for flowing in and out slurry pool：

L_in=L_out+L_re(18),

In formula (1), L_inBe by shower enter slurry pool slurry flow rate, L_outIt is to produce pump by slurries to discharge slurries The slurry flow rate in pond, L_reIt is the slurry flow rate extracted out by slurry pool by circulating pump, its unit is m³·s^-1；Wherein, L_in= F×G/1000m³·s^-1, in order to maintain the constant of concentration of slurry in slurry pool, fraction slurries is discharged slurry pool and is carried out follow-up Crystallization treatment, the flow rate for discharging this fraction slurries of slurry pool can be calculated by formula (19)：

In slurry pool, speed can be expressed as each ion concentration over time：

In formula (20), N_iFor the molar flow rate of slurry pool import and export slurries intermediate ion, unit is mol min^-1, which can lead to Cross formula (21) to be calculated：

N_i=L_inC_i,in-L_reC_i,re-L_outC_i,out(21),

C in formula (21)_i,in、C_i,reAnd C_i,outRespectively by shower enter slurry pool, by circulating pump by slurry pool Ion concentration in slurries extract out, that pump discharge slurry pool is produced by slurries；+ 4 in convolution (20), (21), slurry pool Speed is respectively valency sulphur over time with+6 valency sulphion concentration：

In spraying zone, SO₂It is rapidly absorbed into liquid phase and forms+4 valency sulphur (H₂SO₃、With), SO₂Uptake isSpraying zone formed+4 valency sulphur are in slurry pool and are partly oxidized into+6 valency sulphur.+ 4 valency sulphur of the ammonia process of desulfurization is aoxidized During, the speed that+4 valency sulphur concentrations are reduced is equal to the speed that+6 valency sulphur concentrations increase, and slurries in slurry pool under limit Ion concentration keeps constant, therefore, in formula (22), (23), speed is+4 valency sulphur over time with+6 valency sulphion concentration 0, i.e.,：Then have：

If the oxygenation efficiency of+4 valency sulphur is η,：

In formula (22)～(24), r_reactFor the generating rate of+6 valency sulphur in slurry pool, unit is mol min^-1, which can root Calculated according to following formula：

r_react=r_(IV)V (26)；

Formula (25), (26) are substituted into into formula (24), you can obtain the oxygenation efficiency of+4 valency sulphur：

In the present invention in slurry pool slurries density computing formulaPush away Lead as follows：

During the ammonia process of desulfurization, SO₂Dissolving is into liquid phase and following ionic equilibrium occurs：

+ 4 valency sulphur in slurriesMiddle H₂SO₃,WithBreadth coefficient δ₀、δ₁And δ₂Can be expressed as respectively：

Convolution (27)～(29),WithConcentration can be expressed as respectively:

Convolution (30)～(34), H₂SO₃、WithBreadth coefficient δ₀、δ₁And δ₂Can turn to respectively：

As can be seen that H from formula (35)～(37)₂SO₃,WithBreadth coefficient δ₀、δ₁And δ₂For pH value Function.And from formula (35), be H in the range of 5.0～6.0 in pH₂SO₃Breadth coefficient δ₀Numerical value very little, can ignore. SlurriesInConcentration be δ₁ Concentration be δ₂ It is mainly NH in solution₄HSO₃、(NH₄)₂SO₃With (NH₄)₂SO₄, therefore, the density p of slurries_LApproximately can be calculated as the following formula：

Each model parameter in the present invention is as shown in Table 1.

The model parameter explanation of 1 present invention of table

3. beneficial effect

The technical scheme provided using the present invention, compared with prior art, with following remarkable result：

(1)+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the invention, after pending flue gas enters spray column, in spray Fall in slurry pool after spray liquid counter current contacting under drenching area with spraying by shower, in the air that slurry pool bottom is arranged Distributor can be such that slurries are fully contacted with oxygen, promote the oxidation of+4 valency sulphur.In the corresponding tower body of slurry pool one in the present invention Side produces pump and is connected by producing pipeline and slurries, such that it is able to make slurries constantly discharge from slurry pool, is conducive to maintenance slurries Ion concentration in pond, it is ensured that+4 valencys are thio-oxidizing stable in slurry pool and efficiently carry out；Slurry pool in the present invention is by following Endless tube road is connected with the water inlet of shower, and circulating pump is additionally provided with circulating line, the circulation with the inlet communication of circulating pump Pipeline is also connected with ammoniacal liquor inlet tube, such that it is able to use serum recycle, is conducive to economizing on resources, and passes through ammoniacal liquor inlet tube Fresh ammoniacal liquor is constantly injected, is conducive to adjusting the pH into spray liquid in shower, it is ensured that spray liquid absorbs SO₂Ability.

(2) optimization regulating method of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the invention, is de- based on ammonia process The characteristics of+4 valency sulphur oxidation technology of sulphur absorption product, oxygen of the founding mathematical models to+4 valencys in spray column slurry pool in engineering practice Change process carries out numerical simulation, can calculate the oxygenation efficiency of+4 valency sulphur under different technology conditions using the model, by model meter Inspection formula between calculation value and setting value carries out comparison test to result of calculation, and incorporation engineering is actual adjusting in oxidation trough The technological parameters such as+4 valencys thio-oxidizing Cs, pH and Q, make the oxygenation efficiency of+4 valency sulphur disclosure satisfy that engine request such that it is able to instruct The design and operation of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product, is conducive to+4 valency sulphur of ammonia process of desulfurization absorption product oxidation system The optimization of system.

(3) optimization regulating method of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the invention, its model calculation value 5% is less than with the error between engineering survey value, model can accurately simulate the oxygen of+4 valency sulphur of ammonia process of desulfurization absorption product Change process, so that the design of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product and operation are relatively reliable, improve ammonia process and takes off The stability and economy of sulphur system operation.

Description of the drawings

Fig. 1 is the structural representation of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the present invention；

Fig. 2 is the schematic diagram of spray tower slurry pool model in the present invention；

Fig. 3 is the model computing block diagram in the present invention；

Fig. 4 be+4 valency sulfur oxidation rates measured value with the present invention in model calculation value comparison diagram.

Label declaration in figure：

1st, oxidation fan；2nd, air sparger；3rd, slurries extraction pump；4th, circulating pump；5th, spray column body；501st, slurries Pond；502nd, spraying zone；503rd, gas approach；504th, shower；505th, demister；506th, neat stress outlet；6th, ammoniacal liquor inlet tube； 7th, sample tap.

Specific embodiment

To further appreciate that present disclosure, in conjunction with drawings and Examples, the present invention is described in detail.

Embodiment 1

As shown in figure 1, a kind of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the present embodiment, including spray column body 5, include successively inside the spray column body 5 from top to bottom except fog-zone, spraying zone 502 and slurry pool 501, wherein, in spray column The top of body 5 is provided with neat stress outlet 506, is provided with demister 505 except fog-zone below the neat stress outlet 506, the demisting Device 505 is connected with the technique water tank outside spray column.Shower 504 is provided with the top of spraying zone 502, and in spraying zone 502 The corresponding tower body side in bottom is provided with gas approach 503, on the pipeline being connected with gas approach 503 and neat stress outlet 506 It is equipped with smoke on-line monitoring system.Air sparger 2 is provided with the bottom of slurry pool 501, the air of the air sparger 2 enters Mouth pipeline is connected with oxidation fan 1；It is connected by producing pipeline and slurries extraction pump 3 in 501 corresponding tower body side of slurry pool, And the slurry pool 501 is connected with the water inlet of shower 504 by circulating line.Circulating pump 4 is additionally provided with circulating line, One end on the circulating line near loop slurry outlet is provided with sample tap 7, and the circulating line with the inlet communication of circulating pump 4 Also it is connected with ammoniacal liquor inlet tube 6.PH is equipped with circulating line in slurry pool 501 and with 4 outlet of circulating pump Meter, enters the pH value of the spray liquid of shower such that it is able to slurries in measurement slurry pool in real time and after being passed through ammoniacal liquor regulation.

In the present embodiment, pending flue gas by the gas approach 503 on spray column body 5 turn back into after spray column to On, the slurries counter current contacting in the case where spraying zone 502 is with being sprayed by shower 504 is substantially increased to SO in flue gas₂Removing Effect.In spraying zone SO₂Dissolving generates+4 valency sulphur (NH into liquid phase and with absorbent reaction in spray liquid₄)₂SO₃And NH₄HSO₃, It is stripped of SO₂Flue gas continue up and carry out the demisting of washing process and demister 505 and process, the neat stress for finally giving passes through The neat stress outlet 506 of tower top is discharged, and absorbs SO₂Slurries then fall into spray tower bottom slurry pool 501 in.By slurry The air sparger 2 of 501 bottom of liquid pool is continuously passed through oxygen into slurry pool 501, by+4 valency sulphur (NH₄)₂SO₃With NH₄HSO₃It is oxidized to+6 stable valency sulphur (NH₄)₂SO₄.In running, on the one hand producing pump 3 by slurries constantly makes slurries Fraction slurries in pond 501 are discharged by serum outlet, carry out follow-up crystallization treatment, such that it is able to maintain in slurry pool 501 from Sub- concentration it is constant, make+4 valency sulphur (NH in slurry pool 501₄)₂SO₃And NH₄HSO₃Oxygenation efficiency be able to maintain that it is constant.On the other hand The slurries extracted in slurry pool 501 by circulating pump 4 are delivered to shower 504 and are circulated utilization, such that it is able to economize on resources. Also it is connected with ammoniacal liquor inlet tube 6 with the circulation line of 4 inlet communication of circulating pump, such that it is able to the constantly supplementary ammoniacal liquor in spray liquid To keep spray liquid to SO₂Absorbability, can be by the pH of slurries in the slurry pool 501 that measures adjusting ammoniacal liquor inlet tube The magnitude of recruitment of ammoniacal liquor in 6, so as to the pH for supplementing spray liquid after ammoniacal liquor meets require.

As shown in figure 3, the optimization regulating method of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the present embodiment, its tool Body step is：

Step one, it is defined below model parameter：The D of ammonia method desulfurizing system spray column_R、G、F、Q, with And in spray column bottom slurry pond 501 slurries pH, C_S、V、t_r、μ_LAnd σ_L。

Wherein, D_RFor the diameter of ammonia method desulfurizing system spray column, directly obtained by measurement, unit is m；G is by flue gas The flue gas flow rate of the pending flue gas that import 503 is entered in spray column, is measured by smoke on-line monitoring system, and unit is m³· s^-1；WithRespectively spray column gas approach 503 and neat stress export SO in 506 flue gases₂Concentration, existed by flue gas Line monitoring system is measured, and unit is mg m^-3；F is the liquid-gas ratio in spray column, is the setting value of system operation, and unit is L m^-3；Q is the oxidation air amount in spray column slurry pool 501, and its value is theoretical air requirement Q₀1～4 times, wherein, theoretical oxidation Air capacityUnit is m³·s^-1；PH is the pH value of slurries in slurry pool 501；C_SFor slurry The total sulfur concentration of slurries in liquid pool 501, is+4 valency sulphur concentrationsWith+6 valency sulphur concentrationsSum, its unit are mol L^-1；V For the volume of slurries in slurry pool 501, by the time of staying t for adjusting slurries in slurry pool 501_rIt is controlled, V= 60t_rL_in, unit is m³, the L in the formula_inIt is the slurry flow rate for entering slurry pool 501 by 504 stream of shower, unit is m³·s^-1, by L_in=F × G/1000m³·s^-1Calculated；The viscosity, mu of slurries_LWith surface tension σ_LIt is utilized respectively viscosimeter and table Face tensiometer is measured, and its unit is respectively Pa s and N m^-1；

In the present embodiment, D_RFor 8.6m, t_rFor 17.62min, G is 116.9m³·s^-1,For 1556mg m^-3,For 37mg m^-3, F is 3.5L m^-3, C_sFor 2.2mol L^-1, it is 0.16m that pH is 5.2, Q³·s^-1, μ_LFor 0.5494Pa s, surface tension σ_LFor 67.77N m^-1, according to V=60t_rL_inSlurry volume V in slurry pool 501 can be calculated For 432.55m³。

Model parameter in step 2, input step one, and set C_SIn+4 valency sulphur and+6 valency sulphur initial concentrationAnd meetIn the present embodimentCalculated using the oxygenation efficiency model of+4 valency sulphur The oxygenation efficiency of+4 valency sulphur in slurry pool 501The oxygenation efficiency model for being somebody's turn to do+4 valency sulphur is specific as follows：

In formula (1)For the SO that spray column spraying zone 502 absorbs₂Molar flow rate, unit be mol s^-1, which passes through Formula (2) is calculated：

R in formula (1)_(IV)For the oxidation rate of+4 valency sulphur in slurry pool 501, unit is mol L^-1·min^-1, which presses formula (3) calculated：

In formula (3), k₀For frequency factor, its value is 1.44 × 10⁴；R is ideal gas constant, is 8.31J mol^-1·K^-1；T is temperature in spray column, is 323.15K；For the equilibrium concentration of oxygen at gas-liquid interface in slurry pool 501, unit is mol·L^-1, which passes through formula (4) and is calculated：

In formula (4),For O at gas-liquid interface in slurry pool 501₂Equilibrium partial pressure, unit is Pa, in the present embodiment For 2.13 × 10⁴Pa；H is O₂Solubility coefficient in slurries in slurry pool 501, unit are mol m^-3·Pa^-1, H is by formula (5) calculated：

In formula (5), H⁰For O₂Solubility coefficient in water, its value are 9.45 × 10^-6mol·m^-3·Pa^-1；h_iFor slurries The O that 501 Inner electrolysis matter of pond causes₂Solubility reduces coefficient, and unit is m³·kion^-1；I_iFor each in 501 Inner electrolysis matter of slurry pool The ionic strength of ion, unit are kion m^-3.In the pH value range controlled in ammonia desulfurizing process, H in slurries₂SO₃With NH₃·H₂The concentration of O is low, is negligible, and the electrolyte in slurries refers to NH₄HSO₃、(NH₄)₂SO₃(NH₄)₂SO₄；h_iWith I_iPass through formula (6) respectively and formula (7) is calculated：

h_i=h⁺+h^-+h_G(6),

In formula (6), 501 Inner electrolysis matter NH of slurry pool₄HSO₃、(NH₄)₂SO₃(NH₄)₂SO₄Middle positive and negative ion and be dissolved The numerical value h that causes of oxygen⁺、h^-And h_GAs shown in table 2, C in formula (7)_iFor the concentration of each ion in 501 Inner electrolysis matter of slurry pool, Z_iFor the valence mumber of each ion.

Proportionality constant (the h of each ion in 2 embodiment of table, 1 formula (6)⁺,h^-and h_G)

In formula (3), k_LFor oxygen mass tranfer coefficient in the liquid phase, unit is m s^-1, which is calculated by formula (8)：

In formula (8), ρ_LFor the density of slurries in slurry pool, unit is kg m^-3, which passes through formula (9) and is calculated：

In formula (9), δ₁And δ₂RespectivelyWithBreadth coefficient, wherein,

In formula (10) and (11), K_a1And K_a2Respectively balanced reactionWithReaction equilibrium constant, wherein, lgK_a1=853/T-4.74, lgK_a2=621.9/T-9.278；[H⁺] for hydrionic active concentration in the interior slurries of slurry pool (501), be calculated by pH value.

In formula (8)And d_vsRespectively in diffusion coefficient of the oxygen in slurry pool liquid phase and slurry pool liquid phase, bubble is flat Equal diameter, its unit are respectively m²·s^-1And m,And d_vsCalculated by formula (12), (13) respectively：

In formula (12), α is the associated factors of solvent in slurries in slurry pool, is worth for 2.6；M_BFor molten in slurries in slurry pool The molal weight of agent, unit are g mol^-1, M in the present embodiment_BFor 18g mol^-1；V_AFor the diffusion volume of oxygen molecule, unit For cm³·mol^-1, it is 16.6cm in the present embodiment³·mol^-1。

In formula (13), u_OGFor the superficial gas velocity of slurry pool internal oxidition air, unit is m s^-1, based on which is carried out by formula (14) Calculate：

In formula (3), a is gas-liquid contact interfacial area, and unit is m²·m^-3, calculated by formula (15)：

Gas holdup ε in formula (15), in slurry pool in liquid phase_GCalculated as the following formula：

In formula (3),ConcentrationCalculated as the following formula：

By each parameter substitution formula (1)～(17), simultaneous formula (1)～(17) calculate the oxidation of+4 valency sulphur in slurry pool 501 RateFor 1.1597.

Step 3, by the oxygenation efficiency of calculated+4 valency sulphur in step 2WithBring into Following discriminate is tested, and discriminate is false：

Adjust in being back to step 2WithValue, ifThen increaseAnd reduceIfThen reduceAnd increaseRecalculate r_(IV)V is until above formula establishment, last defeated Go out the oxygenation efficiency of+4 valency sulphurFor 96%.

Step 4, by+4 valency sulfur oxidation rates exported in step 3Carry out with the target set point in Practical Project Relatively, if model calculation valueLess than target set point, then adjusting parameter pH, Q as follows is back in step 2 And C_SIn one or more, and re-start calculating ,+4 valency sulfur oxidation rates exported in step 3It is full Sufficient engine request：The pH of slurries in slurry pool 501 is reduced, step-length is 0.1；Increase oxidation air amount Q, step-length is 0.5；Reduce slurry The total sulfur concentration C of slurries in liquid pool 501_S, step-length is 0.1, C_SReduction the slurry stream that produces of pump 3 is produced by slurries by increase Rate L_outTo realize.Wherein, should be adjusted in following adjusting range during each technological parameter more than adjusting：Slurry pool 501 The pH of interior slurries is 5.0～6.0, C_sFor 1.9～2.3mol/L, actual oxidation air capacity Q and theoretical oxidation air capacity Q₀Ratio m Scope be 1～4.In the present embodiment, in engineering, require that the oxygenation efficiency of+4 valency sulphur is not less than 98%, keeps first step other parameters Constant, it is 5.0 to adjust pH, continues executing with second step and the 3rd step, and the oxygenation efficiency for being calculated+4 valency sulphur is 98.16%.

When oxygenation efficiency model in using the present invention is to instruct the design of oxidative system in Practical Project and run, first root According to the build-in attribute of spray column desulphurization system in Practical Project, such as spray column diameter D_R, into the pending flue gas in spray column 503 flue gas of flue gas flow rate G and spray column gas approach in SO₂ConcentrationDeng, and the ammonia process of desulfurization is inhaled in incorporation engineering The target set point of+4 valency sulfur oxidation rate of product is received, an initial pH value, oxidation air amount Q and C is first given_SIn+4 valency sulphur and+6 The initial concentration of valency sulphurOxygenation efficiency model in the above initial value substitution present invention is calculated into oxygenation efficiencyNumerical value, and by calculated oxygenation efficiencyNumerical value is initial with settingValue is substituted intoIn test, if the discriminate is false, in return to step two, adjust C_SInWith's Value, until above-mentioned discriminate is set up, exports oxidation rate score now/C_S, and which is entered with the target set point in engineering Row compares, if which is unsatisfactory for target set point, by the pH value of slurries, oxidation air amount Q and C in slurry pool_SIn one Or it is multiple, and recalculate, until the oxygenation efficiency of output meets the target set point in engineering.

What deserves to be explained is, inventor (Jia Yong, ACTA Scientiae Circumstantiae, 2014,34 (8)：1～7) disclosed in 2010 One document with regard to ammonia desulfurizing process S (IV) oxidation kinetics scale-model investigation, inventor is based on ammonia process in the above documents The characteristics of flue gas desulfurization technique, the oxidation kinetics process of+4 valency sulphur of accessory substance is carried out in batch (-type) blistering reaction device Experimental study, with reference to the gas holdup under different condition, Oxygen in Liquid equation for mass transfer coefficient in research, is only theoretically deduced+4 The expression formula of valency sulphur oxidation rate, but should the expression formula of+4 valency sulphur oxidations rate can not be used for instructing the fortune of true engineering practice OK, i.e., the design of+4 valency sulphur oxidative system of optimization ammonia process of desulfurization absorption product can not be instructed by the expression formula of the oxidation rate And operation, this also result in the difficult problem of puzzlement inventor's long period.And+4 valency sulphur of ammonia process of desulfurization absorption product in the present invention Oxygenation efficiency model be that inventor continues through substantial amounts of practical studies, with reference to+4 valency of ammonia process of desulfurization absorption product in Practical Project What the truth of sulphur oxidative system found out, the oxygenation efficiency model of+4 valency sulphur in the present invention can be directly used for instructing In true engineering, the design and operation of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product, makes ammonia process of desulfurization spray column slurry pool In (continuous stream bubbling oxidation reaction device), the oxygenation efficiency of+4 valency sulphur disclosure satisfy that engine request.

Embodiment 2：

A kind of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the present embodiment is with embodiment 1.

The optimization regulating method of+4 valency sulphur oxidative system of above-mentioned ammonia process of desulfurization absorption product of the present embodiment, its concrete steps For：

Step one, it is defined below model parameter：The D of ammonia method desulfurizing system spray column_R、G、F、Q, with And in spray column bottom slurry pond 501 slurries pH, C_S、V、t_r、μ_LAnd σ_L。

Wherein, D in above-mentioned parameter_RFor 8.6m, t_rFor 17.62min, G is 116.9m³·s^-1,For 1556mg m^-3,For 37mg m^-3, F is 3.5, C_sFor 2.2mol L^-1, it is 0.16m that pH is 5.4, Q³·s^-1, μ_LFor 0.5494Pa s, Surface tension σ_LFor 67.77N m^-1, according to V=60t_rL_in, slurry pool body slurry volume V is calculated for 432.55m³。

Model parameter in step 2, input step one, and set C_SIn+4 valency sulphur and+6 valency sulphur initial concentrationAnd meetIn the present embodimentCalculated using the oxygenation efficiency model of+4 valency sulphur The oxygenation efficiency of+4 valency sulphur in slurry pool 501The oxygenation efficiency model for being somebody's turn to do+4 valency sulphur is specific as follows：

In formula (1)For the SO that spray column spraying zone 502 absorbs₂Molar flow rate, unit be mol s^-1, which leads to Cross formula (2) to be calculated：

R in formula (1)_(IV)For the oxidation rate of+4 valency sulphur in slurry pool 501, unit is mol L^-1·min^-1, which presses formula (3) calculated：

In formula (3), k₀For frequency factor, its value is 1.44 × 10⁴；R is ideal gas constant, is 8.31J mol^-1·K^-1；T is temperature in spray column, is 323.15K；For the equilibrium concentration of oxygen at gas-liquid interface in slurry pool 501, unit is mol·L^-1, which passes through formula (4) and is calculated：

In formula (4),For O at gas-liquid interface in slurry pool 501₂Equilibrium partial pressure, unit is Pa, in the present embodiment For 2.13 × 10⁴Pa；H is O₂Solubility coefficient in slurries in slurry pool 501, unit are mol m^-3·Pa^-1, H is by formula (5) calculated：

In formula (5), H⁰For O₂Solubility coefficient in water, its value are 9.45 × 10^-6mol·m^-3·Pa^-1；h_iFor slurries The O that 501 Inner electrolysis matter of pond causes₂Solubility reduces coefficient, and unit is m³·kion^-1；I_iFor each in 501 Inner electrolysis matter of slurry pool The ionic strength of ion, unit are kion m^-3.In the pH value range controlled in ammonia desulfurizing process, H in slurries₂SO₃With NH₃·H₂The concentration of O is low, is negligible, and the electrolyte in slurries refers to NH₄HSO₃、(NH₄)₂SO₃(NH₄)₂SO₄；h_iWith I_iPass through formula (6) respectively and formula (7) is calculated：

h_i=h⁺+h^-+h_G(6),

In formula (6), 501 Inner electrolysis matter NH of slurry pool₄HSO₃、(NH₄)₂SO₃(NH₄)₂SO₄The O for causing₂Solubility is reduced Coefficient h_iWith embodiment 1, C in formula (7)_iFor the concentration of each ion in 501 Inner electrolysis matter of slurry pool, Z_iFor the valence mumber of each ion.

In formula (3), k_LFor oxygen mass tranfer coefficient in the liquid phase, unit is m s^-1, which is calculated by formula (8)：

In formula (8), ρ_LFor the density of slurries in slurry pool, unit is kg m^-3, which passes through formula (9) and is calculated：

In formula (9), δ₁And δ₂RespectivelyWithBreadth coefficient, wherein,

In formula (10) and (11), K_a1And K_a2Respectively balanced reactionWith Reaction equilibrium constant, wherein, lgK_a1=853/T-4.74, lgK_a2=621.9/T-9.278；[H⁺] in slurry pool (501) In slurries, hydrionic active concentration, is calculated by pH value.

D in formula (8)_O2And d_vsRespectively in diffusion coefficient of the oxygen in slurry pool liquid phase and slurry pool liquid phase, bubble is flat Equal diameter, its unit are respectively m²·s^-1And m,And d_vsCalculated by formula (12), (13) respectively：

In formula (12), α is the associated factors of solvent in slurries in slurry pool, is worth for 2.6；M_BFor molten in slurries in slurry pool The molal weight of agent, unit are g mol^-1, M in the present embodiment_BFor 18g mol^-1；V_AFor the diffusion volume of oxygen molecule, unit For cm³·mol^-1, it is 16.6cm in the present embodiment³·mol^-1。

In formula (13), u_OGFor the superficial gas velocity of slurry pool internal oxidition air, unit is m s^-1, based on which is carried out by formula (14) Calculate：

In formula (3), a is gas-liquid contact interfacial area, and unit is m²·m^-3, calculated by formula (15)：

Gas holdup ε in formula (15), in slurry pool in liquid phase_GCalculated as the following formula：

In formula (3),ConcentrationCalculated as the following formula：

By each parameter substitution formula (1)～(17), simultaneous formula (1)～(17) calculate the oxidation of+4 valency sulphur in slurry pool 501 RateFor 0.9234.

Step 3, by the oxygenation efficiency of calculated+4 valency sulphur in step 2WithBring into Following discriminate is tested, and discriminate is false：

Adjust in being back to step 2WithValue, ifThen increaseAnd reduceIfThen reduceAnd increaseRecalculate r_(IV)V is until above formula establishment, last defeated Go out the oxygenation efficiency of+4 valency sulphurFor 91.35%.

Step 4, by+4 valency sulfur oxidation rates exported in step 3Carry out with the target set point in Practical Project Relatively, if+4 valency sulfur oxidation rates calculated in step 3The oxygenation efficiency for comparing engine request is low, then return second Step adjusting parameter pH, Q and C_SIn one or more, re-start calculating, the oxidation of+4 valency sulphur that export in step 3 RateMeet engine request, the method for adjustment of parameter is with embodiment 1 in the present embodiment.

Embodiment 3：

A kind of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the present embodiment is with embodiment 1.

The optimization regulating method of+4 valency sulphur oxidative system of above-mentioned ammonia process of desulfurization absorption product of the present embodiment, its concrete steps Close with embodiment 1, its difference is：C in step one_sFor 2.0mol L^-1, pH is 5.4, and other specification is with enforcement Example 1；Calculate in step 2For 1.4643 ,+4 valency sulfur oxidation rates of last output after adjusting in step 3For 99.80%.

If+4 valency sulfur oxidation rates calculated in the 3rd stepThe oxygenation efficiency for comparing engine request is low, then return Two steps as follows adjusting parameter pH, Q and C_SIn one or more, re-start calculating, until the 3rd step output+ 4 valency sulfur oxidation ratesMeet engine request, method is with embodiment 1.

Embodiment 4：

A kind of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the present embodiment is with embodiment 1.

The optimization regulating method of+4 valency sulphur oxidative system of above-mentioned ammonia process of desulfurization absorption product of the present embodiment, its concrete steps Close with embodiment 1, its difference is：C in step one_sFor 2.3mol L^-1, pH is 5.4, and other specification is with enforcement Example 1；Calculate in step 2For 0.5521 ,+4 valency sulfur oxidation rates of last output after adjusting in step 3For 87.51%.

If+4 valency sulfur oxidation rates calculated in the 3rd stepThe oxygenation efficiency for comparing engine request is low, then return Two steps as follows adjusting parameter pH, Q and C_SIn one or more, re-start calculating, until the 3rd step output+ 4 valency sulfur oxidation ratesMeet engine request, method is with embodiment 1.

Embodiment 5：

A kind of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the present embodiment is with embodiment 1.

The optimization regulating method of+4 valency sulphur oxidative system of above-mentioned ammonia process of desulfurization absorption product of the present embodiment, its concrete steps Close with embodiment 1, its difference is：PH in step one is 0.32m for 5.4, Q³·s^-1, the same embodiment of other specification 1；Calculate in step 2For 0.9382 ,+4 valency sulfur oxidation rates of last output after adjusting in step 3For 91.74%%.

If+4 valency sulfur oxidation rates calculated in the 3rd stepThe oxygenation efficiency for comparing engine request is low, then return Two steps as follows adjusting parameter pH, Q and C_SIn one or more, re-start calculating, until the 3rd step output+ 4 valency sulfur oxidation ratesMeet engine request, method is with embodiment 1.

Embodiment 6：

A kind of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the present embodiment is with embodiment 1.

The optimization regulating method of+4 valency sulphur oxidative system of above-mentioned ammonia process of desulfurization absorption product of the present embodiment, its concrete steps Close with embodiment 1, its difference is：PH in step one is 0.48m for 5.4, Q³·s^-1, the same embodiment of other specification 1；Calculate in step 2For 0.9501 ,+4 valency sulfur oxidation rates of last output after adjusting in step 3For 91.83%.

If+4 valency sulfur oxidation rates calculated in the 3rd stepThe oxygenation efficiency for comparing engine request is low, then return Two steps as follows adjusting parameter pH, Q and C_SIn one or more, re-start calculating, until the 3rd step output+ 4 valency sulfur oxidation ratesMeet engine request, method is with embodiment 1.

Embodiment 7：

A kind of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the present embodiment is with embodiment 1.

The optimization regulating method of+4 valency sulphur oxidative system of above-mentioned ammonia process of desulfurization absorption product of the present embodiment, its concrete steps Close with embodiment 1, its difference is：T in step one_rFor 14min, pH is 5.4, according to V=G × F × t_r/(1000 × 60), slurry pool body slurry volume V is calculated for 343.68m³；Calculate in step 2For 0.6755, + 4 valency sulfur oxidation rates of last output after adjusting in step 3For 88.85%.

If+4 valency sulfur oxidation rates calculated in the 3rd stepThe oxygenation efficiency for comparing engine request is low, then return Two steps as follows adjusting parameter pH, Q and C_SIn one or more, re-start calculating, until the 3rd step output+ 4 valency sulfur oxidation ratesMeet engine request, method is with embodiment 1.

Embodiment 8：

A kind of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product of the present embodiment is with embodiment 1.

The optimization regulating method of+4 valency sulphur oxidative system of above-mentioned ammonia process of desulfurization absorption product of the present embodiment, its concrete steps Close with embodiment 1, its difference is：T in step one_rFor 20min, pH is 5.4, according to V=G × F × t_r/(1000 × 60), slurry pool body slurry volume V is calculated for 343.68m³；Calculate in step 2For 0.9419, + 4 valency sulfur oxidation rates of last output after adjusting in step 3For 92.22%.

If+4 valency sulfur oxidation rates calculated in the 3rd stepThe oxygenation efficiency for comparing engine request is low, then return Two steps as follows adjusting parameter pH, Q and C_SIn one or more, re-start calculating, until the 3rd step output+ 4 valency sulfur oxidation ratesMeet engine request, method is with embodiment 1.

Embodiment 9：

In order to verify the reasonability of model, the ammonia method desulfurizing system slurries that 2 × 150MW of sampling and testing boiler matchings are built The pH of slurries in pond,WithPH is measured using Hana HI98128 types pH meter,Using iodometric determination,Adopt With ion chromatography, in slurries, the oxygenation efficiency of+4 valency sulphur can be by formulaCalculated.Experiment measures slurry Liquid pool slurries pH about 5.3～5.4, C_sAbout 1.95～2.16mol L^-1, the oxygenation efficiency about 96.2%～99% of+4 valency sulphur.

Determine model parameter D_RFor 8.6m, t_rFor 17.62min, G is 420833m³·h^-1,For 1556mg m^-3,For 37mg m^-3, it is 0.32m that F is 3.5, Q³·s^-1, while above-mentioned parameter to be brought into+4 valency sulfur oxidation rates of the present invention Model is calculated, and model calculation process is as shown in Figure 3.Model calculation value of the above-mentioned measured value of experiment with the present embodiment is entered Row contrast, as a result as shown in figure 4, in Fig. 4, A, B line is ± 10% error line.Figure 4, it is seen that the model of+4 valency sulphur The error of calculated value and measured value of experiment is less than 10%, and model disclosure satisfy that the required precision of engineer applied.

Below schematically the present invention and embodiments thereof are described, the description does not have restricted, institute in accompanying drawing What is shown is also one of embodiments of the present invention, and actual structure is not limited thereto.So, if the common skill of this area Art personnel are enlightened by which, in the case of without departing from the invention objective, are designed and the technical scheme without creative Similar frame mode and embodiment, all should belong to protection scope of the present invention.

Claims (2)

1. the optimization regulating method of+4 valency sulphur oxidative system of a kind of ammonia process of desulfurization absorption product, its step is：

Step one, it is defined below model parameter：The D of ammonia method desulfurizing system spray column_R、G、F、Q, and spray PH, C of the interior slurries of tower bottom slurry pool (501)_S、V、t_r、μ_LAnd σ_L；

Wherein, D_RFor the diameter of ammonia method desulfurizing system spray column, directly obtained by measurement, unit is m；G is by gas approach (503) into the flue gas flow rate of the pending flue gas in spray column, measured by smoke on-line monitoring system, unit is m³·s^-1；WithRespectively spray column gas approach (503) and neat stress export SO in (506) flue gas₂Concentration, by flue gas On-line monitoring system is measured, and unit is mg m^-3；F is the liquid-gas ratio in spray column, is the setting value of system operation, and unit is L·m^-3；Q is the oxidation air amount in spray column slurry pool (501), and its value is theoretical air requirement Q₀1～4 times, unit is m³·s^-1；PH value of the pH for the interior slurries of slurry pool (501)；C_SFor the total sulfur concentration of the interior slurries of slurry pool (501), it is that+4 valency sulphur are dense DegreeWith+6 valency sulphur concentrationsSum, its unit are mol L^-1；Volumes of the V for the interior slurries of slurry pool (501), by adjustment The time of staying t of the interior slurries of slurry pool (501)_rIt is controlled, V=60t_rL_in, unit is m³, the L in the formula_inIt is by spray Pipe (504) stream enters the slurry flow rate of slurry pool (501), and unit is m³·s^-1, by L_in=F × G/1000m³·s^-1Calculate Arrive；The viscosity, mu of slurries_LWith surface tension σ_LBe utilized respectively viscosimeter and surface tension instrument measured, its unit be respectively Pa s and N·m^-1；

Model parameter in step 2, input step one, and set an initial pH value, oxidation air amount Q and C_SIn+4 valency sulphur and The initial concentration of+6 valency sulphurAnd meetSlurry pool is calculated using the oxygenation efficiency model of+4 valency sulphur (501) oxygenation efficiency of+4 valency sulphur inThe oxygenation efficiency of+4 valency sulphur is specifically by being carried out with drag in slurry pool (501) Calculate：

$\mathrm{\&eta;}=r_{\left(IV\right)}V/M_{{\mathrm{SO}}_2}---\left(1\right),$

In formula (1)For the SO that spray column spraying zone (502) absorbs₂Molar flow rate, unit be mol s^-1, which passes through Formula (2) is calculated：

$M_{{\mathrm{SO}}_2}=G\&times;(C_{{\mathrm{SO}}_2,in}-C_{{\mathrm{SO}}_2,out})/(1000\&times;64)---\left(2\right),$

R in formula (1)_(IV)For the oxidation rate of+4 valency sulphur in slurry pool (501), unit is mol L^-1·min^-1, which presses formula (3) calculated：

$r_{\left(IV\right)}=C_{o_2}^{*}/(\frac{1}{k_{L}a}+\frac{1}{k_0\exp \left(\frac{-2.8\&times;{10}^4}{RT}\right)}\&CenterDot;\frac{1}{{10}^{-0.39pH-1.14}}\&CenterDot;\frac{1}{C_{{\mathrm{SO}}_3^{2-}}^{-0.5}}\&CenterDot;\frac{1}{-4C_{S^{6+}}+9})---\left(3\right),$

In formula (3), k₀For frequency factor, its value is 1.44 × 10⁴；R is ideal gas constant, is 8.31J mol^-1·K^-1；T For temperature in spray column, unit is K；For the equilibrium concentration of oxygen at the interior gas-liquid interface of slurry pool (501), unit is mol L^-1, which passes through formula (4) and is calculated：

$C_{O_2}^{*}={\mathrm{Hp}}_{O_2}^{*}---\left(4\right),$

In formula (4),For O at the interior gas-liquid interface of slurry pool (501)₂Equilibrium partial pressure, unit is Pa；H is O₂In slurry pool (501) solubility coefficient in interior slurries, unit are mol m^-3·Pa^-1, H calculated by formula (5)：

$log\left(\frac{H^0}{H}\right)=h_1{I}_1+h_2{I}_2+...+h_i{I}_i+...---\left(5\right),$

In formula (5), H⁰For O₂Solubility coefficient in water；h_iFor the O that slurry pool (501) Inner electrolysis matter causes₂Solubility is reduced Coefficient, unit are m³·kion^-1；I_iFor the ionic strength of each ion in slurry pool (501) Inner electrolysis matter, unit is kion m^-3, h_iAnd I_iPass through formula (6) respectively and formula (7) is calculated：

h_i=h⁺+h^-+h_G(6),

$I_i=\frac{1}{2}\&Sigma;C_i{Z}_i^2---\left(7\right),$

In formula (6), h⁺、h^-、h_GThe numerical value that respectively electrolyte positive and negative ion and dissolved oxygen cause；C in formula (7)_iFor The concentration of each ion, Z in slurry pool (501) Inner electrolysis matter_iFor the valence mumber of each ion；The pH value controlled in ammonia desulfurizing process In the range of, H in slurries₂SO₃And NH₃·H₂The concentration of O is low, is negligible, and the electrolyte in slurries refers to NH₄HSO₃、 (NH₄)₂SO₃(NH₄)₂SO₄；

In formula (3), k_LFor oxygen mass tranfer coefficient in the liquid phase, unit is m s^-1, which is calculated by formula (8)：

$k_L=0.5g^{5/8}{D}_{O_2}^{1/2}{\mathrm{\&rho;}}_L^{3/8}{\mathrm{\&sigma;}}_L^{-3/8}{d}_{vs}^{1/2}---\left(8\right),$

In formula (8), ρ_LFor the density of the interior slurries of slurry pool (501), unit is kg m^-3, which passes through formula (9) calculating：

${\mathrm{\&rho;}}_L=(99{\mathrm{\&delta;}}_1{C}_{S^{4+}}+116{\mathrm{\&delta;}}_2{C}_{S^{4+}}+132C_{S^{6+}})/1000---\left(9\right),$

In formula (9), δ₁And δ₂RespectivelyWithBreadth coefficient, wherein：

${\mathrm{\&delta;}}_1=\frac{K_{a1}\&lsqb;H^{+}\&rsqb;}{{\&lsqb;H^{+}\&rsqb;}^2+K_{a1}\&lsqb;H^{+}\&rsqb;+K_{a1}{K}_{a2}}---\left(10\right),$

${\mathrm{\&delta;}}_2=\frac{K_{a1}{K}_{a2}}{{\&lsqb;H^{+}\&rsqb;}^2+K_{a1}\&lsqb;H^{+}\&rsqb;+K_{a1}{K}_{a2}}---\left(11\right),$

In formula (10) and (11), K_a1And K_a2Respectively balanced reactionWith Reaction equilibrium constant；[H⁺] for hydrionic active concentration in the interior slurries of slurry pool (501), be calculated by pH value；

In formula (8)And d_vsRespectively gas in diffusion coefficient of the oxygen in slurry pool (501) liquid phase and slurry pool (501) liquid phase The average diameter of bubble, its unit are respectively m²·s^-1And m,And d_vsCalculated by formula (12), (13) respectively：

$D_{O_2}=\frac{7.4\&times;{10}^{-12}{\left({\mathrm{\&alpha;M}}_B\right)}^{0.5}T}{{\mathrm{\&mu;}}_L{V}_A^{0.6}}---\left(12\right),$

$d_{vs}=26D_R{\left(\frac{{\mathrm{gD}}_R^2}{{\mathrm{\&sigma;}}_L}\right)}^{-0.5}{\left(\frac{{\mathrm{gD}}_R^3{\mathrm{\&rho;}}_L^2}{{\mathrm{\&mu;}}_L^2}\right)}^{-0.12}{\left(\frac{u_{OG}}{\sqrt{{\mathrm{gD}}_R}}\right)}^{-0.12}---\left(13\right),$

In formula (12), α is the associated factors of solvent in the interior slurries of slurry pool (501), is worth for 2.6；M_BFor slurry pool (501) entoplasm The molal weight of solvent in liquid, unit are g mol^-1；V_AFor the diffusion volume of oxygen molecule, unit is cm³·mol^-1；

In formula (13), u_OGFor the superficial gas velocity of slurry pool (501) internal oxidition air, unit is m s^-1, based on which is carried out by formula (14) Calculate：

$u_{OG}=Q/({\mathrm{\&pi;D}}_R^2/4)---\left(14\right),$

In formula (3), a is gas-liquid contact interfacial area, and unit is m²·m^-3, calculated by formula (15)：

$a=\frac{6{\mathrm{\&epsiv;}}_G}{d_{VS}}---\left(15\right),$

Gas holdup ε in formula (15), in the interior liquid phase of slurry pool (501)_GCalculated as the following formula：

$\frac{{\mathrm{\&epsiv;}}_G}{{(1-{\mathrm{\&epsiv;}}_G)}^4}=0.25\&times;\left(\frac{u_{OG}{\mathrm{\&mu;}}_L}{{\mathrm{\&sigma;}}_L}\right){\left(\frac{{\mathrm{\&rho;}}_L{\mathrm{\&sigma;}}_L^3}{{\mathrm{g\&mu;}}_L^4}\right)}^{7/24}---\left(16\right),$

In formula (3),ConcentrationCalculated as the following formula：

$C_{{\mathrm{SO}}_3^{2-}}={\mathrm{\&delta;}}_2{C}_{S^{4+}}---\left(17\right),$

Simultaneous formula (1)～(17) calculate the oxygenation efficiency of+4 valency sulphur slurry pool (501) Nei

Step 3, by the oxygenation efficiency of calculated+4 valency sulphur in step 2Bring following formula into test：

$\left|\frac{r_{IV}V}{M_{{\mathrm{SO}}_2}}-\frac{C_{S^{6+}}}{C_s}\right|\&le;0.001$

If the oxygenation efficiency of calculated+4 valency sulphurAbove formula is unsatisfactory for, is adjusted in being back to step 2WithValue, ifThen increaseAnd reduceIfThen reduce And increaseRecalculate r_(IV)V is until above formula establishment, finally exports nowWith the oxygenation efficiency of+4 valency sulphur

Step 4, by+4 valency sulfur oxidation rates exported in step 3Compared with the target set point in Practical Project Compared with if model calculation valueLess than target set point, then be back in step 2 adjusting parameter pH, Q as follows and C_SIn one or more, and re-start calculating ,+4 valency sulfur oxidation rates exported in step 3Meet engineering Require：

The pH of the interior slurries of slurry pool (501) is reduced, step-length is 0.1；Increase oxidation air amount Q, step-length is 0.5；Reduce slurry pool (501) the total sulfur concentration C of interior slurries_S, step-length is 0.1, C_SReduction by increase produce the slurry stream that pump (3) is produced by slurries Rate L_outTo realize.

2. the optimization regulating method of+4 valency sulphur oxidative system of ammonia process of desulfurization absorption product according to claim 1, its feature It is：Adjusting parameter pH, Q, C in step 4_SParameter area require it is as follows：The pH of the interior slurries of slurry pool (501) be 5.0～ 6.0, C_sFor 1.9～2.3mol/L, actual oxidation air capacity Q and theoretical oxidation air capacity Q₀Ratio m scope be 1～4.