CN103207608A - Evaluation and control method for selective non-catalytic reduction NOx environment loads of cement plant - Google Patents

Abstract

The invention discloses an evaluation and control method for selective non-catalytic reduction NOx environment loads of a cement plant and belongs to the technical field of cement production environment safety. The method is characterized in that for additional effects caused by nitrous oxide (NOx) emission reduction through implementation of a selective non-catalytic reduction (SNCR) technology, for example, factors such as gaseous pollutants of NH3, CO and SO2 and the increased coal consumption, multi-factor, multi-level and multi-object online monitoring and effect evaluation are conducted according to a set environmental influence quantitative index system and a denitration efficiency quantitative index system, so that the NOx emission can be reduced, and simultaneously, the cement production is stable, the whole environment load is reduced, and the greening process of cement industries is boosted.

Description

Cement mill SNCR NOx carrying capacity of environment is estimated and control method

Technical field

The invention belongs to manufacture of cement Environmental security technical field, be specifically related to cement mill SNCR NOx carrying capacity of environment evaluation and control method.

Background technology

The invention discloses cement mill SNCR NOx carrying capacity of environment evaluation and control method, belong to manufacture of cement Environmental security technical field.

The NOx(oxides of nitrogen) be the NO(nitrogen monoxide) and NO ₂The sum total of (nitrogen dioxide) is common atmosphere pollution, and is very big to the detrimental effect of environment, and materials such as NOx and CO, VOC generate O through photochemical reaction ₃Deng secondary pollution, bring out the city photo-chemical smog, and then environment is caused bigger pollution, stimulate the human lung, cause the factor of the respiratory disease of difficult opposing flu and so on.According to the data of carrying out for the first time national pollution source generaI investigation in 2007, the NOx that produces in the cement production process, wherein NO accounts for 90%～95%, and new type nonaqueous cement kiln NOx average emission coefficient is 1100mg/Nm ³China's cement output surpassed 1,800,000,000 tons in 2010, and about 1,200,000,000 tons of cement clinker output are 1100mg/Nm according to investigation data NOx average emission ³, grog per ton produces 1.8kg NOx approximately.Wherein, cement industry discharging NOx was about 2,200,000 tons in 2010, and the dischargings in 1/10th, 2011 that account for national NOx discharge capacity in 2010 are increased to 384.3 ten thousand tons of NOx.China's cement output occupies the first in the world at present, and cement industry is the third-largest NOx emission source after China's electric power, the vehicle exhaust, and therefore the NOx to cement kiln carries out decrement treatment, has great importance.

For cement industry, existing " cement industry atmosphere pollutants emission standards " regulation NOx emission limit of China still is 800mg/Nm ³But more provinces and cities have stipulated stricter NOx emission limit, and what have is low to moderate 200mg/Nm ³Along with development of times, the NOx emission standard of cement industry can increasingly stringent, and will along with country to continuing to increase with the development of denitration technology of NOx emission control dynamics and strict further.

Nowadays, under the overall background of economic, social sustainable development, the large-scale cement enterprise of China has enforced environmental protective measure by supervision department and has developed into the cement industry development orientation is being coordinated the pollution-free industry of melting altogether with physical environment.Environmental friendliness is the key character that the cement development enters the environmental stage, and for the technology of using a kind of new reduction disposal of pollutants, whether estimate it is principle with " reducing discharging oxides of nitrogen on the basis that guarantees cement stabilizing production; can not bring too much other extra resources; energy resource consumption and pollutant emission ", how to control this denitration technology of improvement according to the evaluation result of carrying capacity of environment and the actual conditions of each flow process of manufacture of cement, method relates to cement products, flow process, operation, equipment etc. are multi-level, comprise resource consumption, energy resource consumption, environmental pollution, a plurality of factors such as production management and quality control, therefore it is above-mentioned multi-level to need foundation to contain, the manufacture of cement carrying capacity of environment quantitative test of multifactor index system and the new method of evaluation instruct cement industry to develop to the ecotype.

SNCR (SNCR) technology is that the NOx in the flue gas is carried out the terminal technology of handling, namely by in kiln, spraying into reductive agent (ammonia, urea etc.), having under the condition of oxygen, chemical reaction takes place in the NOx in ammine selective ground and the flue gas, generate harmless nitrogen G﹠W, make NOx obtain reduction.The reduction of NOx is between 10%～75%.Suppose that former NOx discharge capacity is the 1.6kg/t grog, if the reduction of NOx 40%, then to reduce discharging high-volume be the 0.64kg/t grog to NOx.

The chemical reaction of eliminating principle is as follows:

The removing of NO (NOx90%-95% that NO accounts for generation):

4NO+4NH ₃+ O ₂→ 4N ₂+ 6H ₂O (formula I)

6NO+4NH ₃→ 5N ₂+ 6H ₂O (formula II)

NO ₂Remove (NO ₂Account for the NOx5%-10% of generation):

2NO ₂+ 4NH ₃+ O ₂→ 3N ₂+ 6H ₂O (formula III)

6NO ₂+ 8NH ₃→ 7N ₂+ 12H ₂O (formula IV)

There have been document and patent to relate to low NOx control technology in the cement production process.But, method and technology that these documents and patent only are conceived to how to burn by control in cement production process reduce discharging NOx, do not come the NOx control technology that cement production process produces is carried out holistic approach from the angle in manufacture of cement cycle, do not consider other additional effect that production brings to cement owing to implement the NOx control technology, for example other gas pollutants NH ₃, CO, SO ₂Deng discharging and the increasing of coal consumption.

The present invention has the data acquisition basic function, also have the expanded functions such as Energy Flow Analysis, energy stream time series analysis and the analysis of energy-saving and emission-reduction potentiality between production process, the integrated environment load angle that reduces discharging oxides of nitrogen when using the SNCR technology during from manufacture of cement and reduce, consider other additional effect that production brings to cement owing to implement the NOx control technology, comprise gas pollutant NH ₃, CO, SO ₂Deng discharging and the factor that increases of coal consumption, the environment focus of each flow process of identification manufacture of cement is also controlled adjustment to manufacture of cement, solved multifactor in the manufacture of cement flow process, multi-level, a target-rich environment load identification difficult problem, for cement industry, enterprise carry out carrying capacity of environment management, the analysis of energy-saving and emission-reduction potentiality and effect assessment, the method of science practicality is provided, can have instructed the cement mill to carry out the work that oxides of nitrogen reduced discharging, reduced integrated environment load and steady production.

Summary of the invention

It is principle that the present invention is intended to " when the basis application SNCR technology that guarantees cement stabilizing production effectively reduces discharging oxides of nitrogen; can not bring too much other extra resources; energy resource consumption and pollutant emission ", come the identification cement industry to reduce discharging oxides of nitrogen and reduce the carrying capacity of environment behavior, basic function with data acquisition, also has the Energy Flow Analysis between production process, the integrated environment load angle that reduces discharging oxides of nitrogen when using the SNCR technology during from manufacture of cement and reduce, consider other additional effect that production brings to cement owing to implement the NOx control technology, comprise gas pollutant NH ₃, CO, SO ₂Deng discharging and the factor that increases of coal consumption, environment focus that can identification manufacture of cement flow process, and manufacture of cement controlled adjustment, solve and how to carry out a difficult problem multifactor, multi-level, the identification of target-rich environment load when manufacture of cement is used the SNCR technology, for cement industry, enterprise carry out carrying capacity of environment management, the analysis of energy-saving and emission-reduction potentiality and effect assessment, the method of science practicality is provided, can have instructed the cement mill to carry out the work that oxides of nitrogen reduced discharging, reduced integrated environment load and steady production.Instruct and advance the greenization process of cement industry accordingly effectively, help enterprise to formulate the measure that effectively reduces the product carrying capacity of environment, and provide the precise information of product and raw-material resource and environment to departments of government, provide and provide powerful support for for entering friendly environment society, meet the requirement of developing a circular economy, building a conservation-minded society.

Need to prove that in actual industrial production, reduce discharging oxides of nitrogen and often be referred to as denitration, two terms of the present invention's " denitration " and " reduction of discharging oxides of nitrogen " are general.

The invention is characterized in, be to reduce discharging in the carrying capacity of environment evaluation and computing machine on-line control system of NOx a cement mill SNCR SNCR technology that comprises central control computer, realizes according to following steps successively:

Step (1), make up one be subjected to described in the carrying capacity of environment evaluation that reduces discharging NOx of the cement mill SNCR SNCR technology of control computer control with the computing machine on-line control system, comprising the storage unit of in the zone, cement mill, setting up and equipping following quantifying: the special ammonia water storage tank, the pure water storage tank, compressed air reservoir, in addition, also be provided with and comprise standby tank used for storing ammonia, and auxiliary equipment and equipment: spray gun, unload ammonia device, exhaust-valve, flexible hose and interface, the pipeline that connects each denitration module, lightning protection canopy and lightning protection facility and equipment, and to the tank car that transports ammoniacal liquor, fire fighting device, fire-water supply reserves working space, wherein:

The special ammonia water storage tank, storage is in order to the ammoniacal liquor NH of reducing NOx ₃H ₂O,

Pure water storage tank, storage be in order to cleaning denitration device and the pure water of weak ammonia when needing,

Compressed air reservoir, storage be in order to implementing the pressurized air of denitration operation,

In accordance with international practices, the cement mill has Chemical Analysis Lab to use national standard " technical analysis of coal " that the coal of this each batch is measured its as received basis net calorific value,

Install at the coal powder injection pipe place of dore furnace in order to measuring the flowmeter of dore furnace coal consumption Mcoal (c), unit is in " kgce/t cl ", i.e. and " kilogram standard coal equivalent/ton grog ",

Install in order to measure the flowmeter of rotary kiln coal consumption amount Mcoal (k) at coal powder injection pipe place at rotary kiln, and unit is " kgce/t cl ", i.e. and " kilogram standard coal equivalent/ton grog ",

Middle control computer initialization, set following parameter:

Wherein, utilize spray gun spray ammonia sign in the dore furnace to come into effect the SNCR technology,

I: expression by middle control computer implement monitoring when i days an of calendar month, record n time altogether, n is numerically equal to the fate when individual calendar month, n ∈ 28,30,31},

Di: implemented the hourage of SNCR technology in i days, i.e. denitration activity duration of accumulative total in the same day,

η (Di): i days average denitration operating rates, η (Di)=Di/24, threshold value η (Di) min 〉=45%,

∑ Di: represent the adding and value of Di of m calendar month, i.e. expression is when an of that month denitration activity duration of calendar month accumulative total,

M represents a moon sequence number, m=1, and 2 ..., 12,

η (∑ Di) expression SNCR technology is implemented the hourly average denitration operating rate of the moon,

η(∑Di)=∑Di/(24n)，

Threshold value η (∑ Di) min 〉=40%,

M:m ∑ Di of ∑ (∑ Di) adds and value, represents the denitration activity duration of this calendar year accumulative total,

The annual denitration operating rate that η (∑ (∑ Di) m) expression SNCR technology is implemented,

$\mathrm{\η}\left(\underset{m=1}{\overset{12}{\mathrm{\Σ}}}{\left(\mathrm{\ΣDi}\right)}_m\right)=\left[\underset{m=1}{\overset{12}{\mathrm{\Σ}}}{\left(\mathrm{\ΣDi}\right)}_m\right]/\left(24\mathrm{mn}\right),$

Threshold value $\mathrm{\η}\left(\underset{m=1}{\overset{12}{\mathrm{\Σ}}}{\left(\mathrm{\ΣDi}\right)}_m\right)\min \≥35\%,$

The condition that the condition of producing according to cement stabilizing, best stove coal consumption are implemented than, energy-conservation basic demand and SNCR technology is set the threshold value of dore furnace and rotary kiln coal consumption and its coal consumption ratio, and the coal consumption of described dore furnace and rotary kiln than the scope of ρ is:

1.5-10%≤ρ≤1.5+10%, the best is ρ=1.5,

$\mathrm{\ρ}=\frac{\mathrm{Mcoal}\left(c\right)}{\mathrm{Mcoal}\left(k\right)}$

The scope of the temperature T calciner of dore furnace is: 850 ℃≤Tcalciner≤1050 ℃;

Step (2), various described storage element all are provided with the flow measurement device in order to the stoichiometric consumption amount,

Set: the lower limit of the real time capacity of ammoniacal liquor tank farm stock, pure water storage tank and compressed air reservoir is respectively 30% of its storage capacity, and described middle control computer is controlled ammoniacal liquor tank farm stock, pure water storage and pressurized air storage successively according to the following steps:

After the SNCR technology is implemented, at ammoniacal liquor consumption M _NH3H2OMore than or equal to 70%S ' _NH3H2OThe time, send the instruction that replenishes the ammoniacal liquor stock, S ' _NH3H2OBe the ammoniacal liquor max cap. of tank used for storing ammonia,

After the SNCR technology is implemented, at pure water consumption M _H2OMore than or equal to 70%S ' _H2OThe time, send the instruction that replenishes the pure water stock, S ' _H2OBe the pure water max cap. of pure water pot,

After the SNCR technology is implemented, at compressed air consumption M _AirMore than or equal to 70%S ' _AIRThe time, send the instruction that replenishes the pressurized air stock, S ' _AIRBe the pressurized air max cap. of compressed air tank,

The foundation system of tracing to the source is followed the trail of the raw materials used quality of implementing the SNCR technology,

(3), in middle control computer, set up following environmental impact quantizating index set { M _NH3H2O, M _H2O, M _Air, Mcoal (c), Mcoal (k), E _SNCR, TC _AIR, TC _H2O, TC _NH3H2O, M ⁰ _SO2, M _SO2, M ⁰ _CO, M _CO, M _Slip1, M _Slip2, M _Slip3, M ¹ _NOx}:

Mcoal (c): the coal consumption of dore furnace, require Mcoal (c)≤72kgce/t cl,

Mcoal (k): the coal consumption of rotary kiln, require Mcoal (k)≤50kgce/t cl,

E _SNCR: the extra electric weight that enforcement SNCR technology that independent ammeter measures consumes is installed, is required E _SNCR≤ 10kWh/t cl,

TC _NH3H2O: the transported on trucks distance of special transportation ammoniacal liquor requires TC _NH3H2O≤ 100km,

TC _H2O: the transported on trucks distance of transportation pure water requires TC _H2O≤ 80km,

TC _AIR: transport compressed-air actuated transported on trucks distance, require TC _AIR≤ 80km,

M ⁰ _SO2: before implementing the SNCR technology at every turn, the SO in the suspended preheater C1 exit that records with the gas componant tester ₂Discharge capacity requires M ⁰ _SO2≤ 30mg SO ₂/ Nm ³,

M ⁰ _CO: before coming into effect the SNCR technology, record the CO discharge capacity in suspended preheater C1 exit with the gas componant tester at every turn, require M ⁰ _CO≤ 100mg CO/Nm ³,

M _SO2: after coming into effect the SNCR technology at every turn, after 5 minutes stabilization time, the SO in the suspended preheater C1 exit that records with the gas componant tester ₂Discharge capacity requires M _SO2≤ 25mg SO ₂/ Nm ³,

M _CO: after coming into effect the SNCR technology, after 5 minutes stabilization time, the CO discharge capacity in the suspended preheater C1 exit that records with the gas componant tester requires M at every turn _CO≤ 110mg CO/Nm ³,

Under the prerequisite of manufacture of cement stable operation, according to SNCR technical characterstic and the potential safety hazard that prevents that the ammonia leakage from causing, stipulate following control threshold value,

M _Slip1: when unloading ammonia, unloading ammonia point with the amount of ammonia slip that the gas componant tester records, require M at every turn _Slip1≤ 15mgNH ₃/ Nm ³,

M _Slip2: after coming into effect the SNCR technology, after 5 minutes stabilization time, with the amount of ammonia slip that the gas componant tester records, require M in suspended preheater C1 exit at every turn _Slip2≤ 10mg NH ₃/ Nm ³,

M _Slip3: after coming into effect the SNCR technology, after 5 minutes stabilization time, with the amount of ammonia slip that the gas componant tester records, require M at spray ammonia mouth place at every turn _Slip3≤ 30mg NH ₃/ Nm ³,

M ¹ _NOx: after coming into effect the SNCR technology at every turn, after 5 minutes stabilization time, the NOx discharge capacity that records with the gas componant tester in suspended preheater C1 exit, according to the national standard of measurement of correlation NOx, with measured value all to be converted into NO ₂Meter requires M ¹ _NOx≤ 400mgNO ₂/ Nm ³,

Simultaneously, set up denitration efficiency quantizating index collection { η (Di), η (∑ Di), η (∑ (∑ Di) m, M ⁰ _NOx, M ¹ _NOx, Δ NOx, η (c), wherein:

M ⁰ _NOx: before coming into effect the SNCR technology at every turn, the NOx discharge capacity that records with the gas componant tester in suspended preheater C1 exit, with measured value all to be converted into NO ₂Meter,

Δ NOx: denitration rate, Δ NOx=(M ⁰ _NOx-M ¹ _NOx)/M ⁰ _NOx, work as M ⁰ _NOx≤ 500 o'clock, require Δ NOx 〉=55%,

η (c): the cement production system running rate, namely dore furnace and rotary kiln operation running rate require η (c) 〉=70%;

Step (4), middle control computer are monitored and each parameter of On-line Control in real time according to following steps:

Step (4.1), judgement are before coming into effect the SNCR technology, and whether following parameter value reaches following requirement simultaneously:

850℃≤Tcalciner≤1050℃，

Mcoal(c)≤72，

Mcoal(k)≤50，

1.5-10%≤ρ≤1.5+10%, and keep optimum value ρ=1.5 as far as possible,

M ⁰ _SO2≤30，

M ⁰ _CO≤100，

If: there is any one parameter not reach requirement, then adjusts the manufacturing parameter of dore furnace and rotary kiln, make its stable operation in setting range;

Step (4.2), judgement M ⁰ _NOx〉=600 are not,

If M ⁰ _NOx＜600, cement mill Central Control Room managerial personnel judge whether to implement the SNCR technology voluntarily according to this factory's production run cost and environmental protection requirement up to standard,

If M ⁰ _NOx〉=600, then start to implement the SNCR technology, and judge that following parameter is whether in threshold range:

M _Slip2≤10,

M _Slip3≤30,

M _SO2≤25,

M _CO≤110，

850℃≤Tcalciner≤1050℃，

Mcoal(c)≤72，

If when calciner temperature Tcalciner exceeds threshold value, then need in time stop to spray ammonia, in order to avoid cause waste ammoniacal liquor, and detect the coal consumption Mcoal (c) of dore furnace,

If Mcoal (c) exceeds threshold value, then stop to spray ammonia, whether artificial judgment must carry out the enforcement of SNCR technology this moment,

If M _SO2Exceed threshold value, then stop to spray ammonia, detect the flue stopping state,

If M _Slip2, M _COAll exceed threshold value, then stop to spray ammonia, and detect the dore furnace situation of leaking out,

If M _Slip3Exceed threshold value, then stop to spray ammonia, and detect the sealing of spray gun,

If M when unloading ammonia _Slip1Exceed threshold value, then wash the scene with clear water;

If E _SNCRExceed threshold value, then do detection to unloading ammonia, spray ammonia system and compressed air pump, the checkout facility aging conditions,

If cement mill kiln running rate greater than 70% situation under, (∑ (∑ Di) m is lower than threshold value for the operating rate of SNCR technology statistics η (Di), η (∑ Di) and η, then made the prompting of " the SNCR The Application of Technology is on the low side " by middle control computer, by the Central Control Room managerial personnel production stability of cement kiln is carried out complete detection, and consider that the overall technology of SNCR is implemented environment to be detected.

Effect of the present invention is:

(1) the present invention has the data acquisition basic function, also has the Energy Flow Analysis between production process, the integrated environment load angle that reduces discharging NOx when using the SNCR technology during from manufacture of cement and reduce considers that other additional effect that production brings to cement owing to implement the NOx control technology comprise gas pollutant NH ₃, CO, SO ₂Factor such as increase with coal consumption, have investment and the cheap advantage of operating cost.

(2) environment focus that can identification manufacture of cement flow process, and manufacture of cement controlled adjustment, carry out multifactor, multi-level, multiobject on-line monitoring and effect assessment according to environmental impact quantizating index system and the denitration efficiency quantizating index system set, so that stabilizing cement is produced when reducing discharging NOx, reduce the greenization process that integrated environment is loaded and advanced cement industry.

(3) instruct and advance the greenization process of cement industry effectively, help enterprise to formulate the measure that effectively reduces the product carrying capacity of environment, and provide the precise information of product and raw-material resource and environment to departments of government, provide and provide powerful support for for entering friendly environment society, meet the requirement of developing a circular economy, building a conservation-minded society.

Description of drawings

Fig. 1 is that cement mill of the present invention SNCR NOx carrying capacity of environment is estimated and the control method procedure chart;

Embodiment

Below according to Fig. 1 of Figure of description, and embodiment further explains to this invention.

The Cement plant design using calcium scale is 2000t grog/sky among the embodiment, and actual output is 2500t grog/sky.

Make up one be subjected to described in the carrying capacity of environment evaluation that reduces discharging NOx of the cement mill SNCR SNCR technology of control computer control with the computing machine on-line control system, comprising the storage unit of in the zone, cement mill, setting up and equipping following quantifying: the special ammonia water storage tank, the pure water storage tank, compressed air reservoir, in addition, also be provided with and comprise standby tank used for storing ammonia, and auxiliary equipment and equipment: spray gun, unload ammonia device, exhaust-valve, flexible hose and interface, the pipeline that connects each denitration module, lightning protection canopy and lightning protection facility and equipment, and to the tank car that transports ammoniacal liquor, fire fighting device, fire-water supply reserves working space, wherein:

The special ammonia water storage tank, storage is in order to the ammoniacal liquor NH of reducing NOx ₃H ₂O,

Pure water storage tank, storage be in order to cleaning denitration device and the pure water of weak ammonia when needing,

Compressed air reservoir, storage is in order to implement the pressurized air of denitration operation.

At the flow measurement device of various described storage element settings in order to the stoichiometric consumption amount, and set up the system of tracing to the source and follow the trail of the raw materials used quality of implementing the SNCR technology.

Middle control computer initialization, set following parameter:

Before implementing the SNCR technology, in accordance with international practices, the cement mill has Chemical Analysis Lab to use national standard " technical analysis of coal " that the coal of this each batch is measured its as received basis net calorific value.

Install at the coal powder injection pipe place of dore furnace in order to measuring the flowmeter of dore furnace coal consumption Mcoal (c),

Record Mcoal (c)=62＜72kgce/t cl, meet the requirements.

Install at the coal powder injection pipe place of rotary kiln in order to measuring the flowmeter of rotary kiln coal consumption amount Mcoal (k),

Record=41＜50kgce/t cl, meet the requirements.

The condition that the condition of producing according to cement stabilizing, best stove coal consumption are implemented than, energy-conservation basic demand and SNCR technology is set the threshold value of dore furnace and rotary kiln coal consumption and its coal consumption ratio, and the coal consumption of described dore furnace and rotary kiln than the scope of ρ is:

$\mathrm{\ρ}=\frac{\mathrm{Mcoal}\left(c\right)}{\mathrm{Mcoal}\left(k\right)}$

1.5-10%≤ρ≤1.5+10%, the best is ρ=1.5,

According to above-mentioned measured value, ρ=62/41=1.512 meets the requirements.

The temperature T calciner=780 of dore furnace ℃, not in the scope of 850 ℃≤Tcalciner≤1050 ℃, then adjust the manufacturing parameter of dore furnace and rotary kiln, make its stable operation in setting range,

Monitoring again afterwards, in the scope of 850 ℃≤Tcalciner≤1050 ℃, is then carried out following steps by the temperature T calciner=980 of dore furnace ℃.

In middle control computer, set up following environmental impact quantizating index set { M _NH3H2O, M _H2O, M _Air, Mcoal (c), Mcoal (k), E _SNCR, TC _AIR, TC _H2O, TC _NH3H2O, M ⁰ _SO2, M _SO2, M ⁰ _CO, M _CO, M _Slip1, M _Slip2, M _Slip3, M ¹ _NOx}:

Middle control computer is monitored and each parameter of On-line Control in real time according to following steps:

Judgement is before coming into effect the SNCR technology, and whether following parameter value reaches following requirement simultaneously:

850℃≤Tcalciner≤1050℃，

Mcoal(c)≤72，

Mcoal(k)≤50，

1.5-10%≤ρ≤1.5+10%, and keep optimum value ρ=1.5 as far as possible,

M ⁰ _SO2≤30，

M ⁰ _CO≤100，

If M ⁰ _NOx〉=600, then start to implement the SNCR technology, and judge that following parameter is whether in threshold range:

M _Slip2≤10,

M _Slip3≤30,

M _SO2≤25,

M _CO≤110，

850℃≤Tcalciner≤1050℃，

Mcoal(c)≤72，

Control computer Monitoring Data in transferring, after a period of time T=2 hour,

Record M _NH3H2O=43m ³＞70%S ' _NH3H2O=70%*60m ³=43m ³, then send the instruction that replenishes the ammoniacal liquor stock,

Record M _H2O=57m ³＞70%S ' _H2O=70%*80m ³=56m ³, then send the instruction that replenishes the pure water stock,

Record M _AIR=48m ³＜70%S ' _H2O=70%*80m ³=56m ³, then continue monitoring,

Wherein, S ' _NH3H2O=60m ³Be the max cap. of tank used for storing ammonia,

S ' _H2O=80m ³Be the max cap. of pure water pot,

S ' _AIR=80m ³Max cap. for compressed air tank.

For implementing the used raw material of SNCR technology, record its transportation range, and judge whether within predetermined distance.

Ammoniacal liquor transports apart from TC _NH3H2O=70km＜100km meets the requirements,

Pure water transports apart from TC _H2O=20km＜100km meets the requirements,

Pressurized air transports apart from TC _AIR=90km＞80km judges the overshoot distance, then changes producer, makes transportation range reach minimum.

Before implementing the SNCR technology, record suspended preheater C1 exit SO with the gas componant tester ₂Discharge capacity,

M ⁰ _SO2=5＜30mg SO ₂/ Nm ³, meet the requirements,

Before implementing the SNCR technology, record suspended preheater C1 exit CO discharge capacity with the gas componant tester,

M ⁰ _CO=52＜100mg CO/Nm ³, meet the requirements,

Before coming into effect the SNCR technology, the NOx discharge capacity M that records with the gas componant tester in suspended preheater C1 exit ⁰ _NOx, according to the national standard of measurement of correlation NOx, with measured value all to be converted into NO ₂Meter,

M ⁰ _NOx=350＜600mg NO ₂/ Nm ³, cement mill Central Control Room managerial personnel are according to this factory's production run cost and environmental protection requirement up to standard, and judging does not need to implement the SNCR technology.

Continue monitoring, after a period of time T=1 hour, record M ⁰ _NOx=480＜600mg NO ₂/ Nm ³, then Central Control Room managerial personnel in cement mill are according to this factory's production run cost and environmental protection requirement up to standard, and judging needs to implement the SNCR technology this moment.

Utilize spray gun spray ammonia sign in the dore furnace to come into effect the SNCR technology.

After coming into effect the SNCR technology, after 5 minutes stabilization time, the SO in the suspended preheater C1 exit that records with the gas componant tester ₂Discharge capacity M _SO2=4＜25mg SO ₂/ Nm ³, meet the requirements,

After coming into effect the SNCR technology, after 5 minutes stabilization time, the CO discharge capacity M in the suspended preheater C1 exit that records with the gas componant tester _CO=61＜110mg CO/Nm ³, meet the requirements,

After coming into effect the SNCR technology, after 5 minutes stabilization time, the NOx discharge capacity M that records with the gas componant tester in suspended preheater C1 exit ¹ _NOx=390＜400mgNO ₂/ Nm ³, meet the requirements,

But denitration rate Δ NOx=is (M ⁰ _NOx-M ¹ _NOx)/M ⁰ _NOx=(480-390)/and 480=22.9%＜55%, do not meet and work as M ⁰ _NOx≤ 500 o'clock, the requirement of Δ NOx 〉=55%,

Then made the prompting of " the SNCR The Application of Technology is on the low side " by middle control computer, adjust the manufacture of cement parameter, continue monitoring.

After a period of time T=1 hour, the NOx discharge capacity M that records with the gas componant tester in suspended preheater C1 exit ¹ _NOx=180＜400mgNO ₂/ Nm ³, meet the requirements,

Denitration rate Δ NOx=(M ⁰ _NOx-M ¹ _NOx)/M ⁰ _NOx=(480-180)/and 480=62.5＞55%, meet the requirements.

Under the prerequisite of manufacture of cement stable operation, according to SNCR technical characterstic and the potential safety hazard that prevents that the ammonia leakage from causing, monitor following control parameter:

When unloading ammonia, unloading the amount of ammonia slip M that ammonia point records with the gas componant tester _Slip1=20＞15mg NH ₃/ Nm ³, undesirable, then wash the scene with clear water, up to meeting the requirements.

After coming into effect the SNCR technology, after 5 minutes stabilization time, the amount of ammonia slip M that records with the gas componant tester in suspended preheater C1 exit _Slip2=35＞10mg NH ₃/ Nm ³, then stop to spray ammonia, and detect the dore furnace situation of leaking out, up to meeting the requirements.

After coming into effect the SNCR technology, after 5 minutes stabilization time, the amount of ammonia slip M that records with the gas componant tester at spray ammonia mouth place _Slip3=32＞30mg NH ₃/ Nm ³, then stop to spray ammonia, and detect the sealing of spray gun, up to meeting the requirements.

After coming into effect the SNCR technology, after 5 minutes stabilization time, the SO that records with the gas componant tester at spray ammonia mouth place ₂Discharge capacity M _SO2=40＞25mg NH ₃/ Nm ³, then stop to spray ammonia, detect the flue stopping state, up to meeting the requirements.

Continue monitoring, after a period of time, find Mcoal (c)=75＞72kgce/t cl, undesirable, then stop to spray ammonia, artificial judgment can not be carried out the enforcement of SNCR technology this moment, then adjusts the job parameter of dore furnace, makes its stable operation in setting range.

Continue monitoring, after coming into effect the SNCR technology, calciner temperature Tcalciner=800 ℃, not in the scope of 850 ℃≤Tcalciner≤1050 ℃, then in time stop to spray ammonia, in order to avoid cause waste ammoniacal liquor, and detect the coal consumption Mcoal (c) of dore furnace, at this moment find Mcoal (c)=74＞72kgce/t cl, undesirable, then artificial judgment can not be carried out the enforcement of SNCR technology this moment, then continues to adjust the job parameter of dore furnace, makes its stable operation in setting range.

After a period of time, the consistent operation of SNCR, the independent ammeter of installation measures implements the extra electric weight E that the SNCR technology consumes _SNCR=3.7＜10kWh/t cl meets the requirements.

After a period of time, measure E again _SNCR=12＞10kWh/t cl exceeds threshold value, then does detection to unloading ammonia, spray ammonia system and compressed air pump, and the checkout facility aging conditions is up to meeting the requirements.

Simultaneously, set up denitration efficiency quantizating index collection { η (Di), η (∑ Di), η (∑ (∑ Di) m, M ⁰ _NOx, M ¹ _NOx, Δ NOx, η (c), wherein:

I: expression by middle control computer implement monitoring when i days an of calendar month, record n time altogether, n is numerically equal to the fate when individual calendar month, n ∈ 28,30,31},

Di: implemented the hourage of SNCR technology in i days, i.e. denitration activity duration of accumulative total in the same day,

η (Di): i days average denitration operating rates, η (Di)=Di/24, threshold value η (Di) min 〉=45%,

∑ Di: represent the adding and value of Di of m calendar month, i.e. expression is when an of that month denitration activity duration of calendar month accumulative total,

M represents a moon sequence number, m=1, and 2 ..., 12,

η (∑ Di) expression SNCR technology is implemented the hourly average denitration operating rate of the moon,

η(∑Di)=∑Di/(24n)，

Threshold value η (∑ Di) min 〉=40%,

M:m ∑ Di of ∑ (∑ Di) adds and value, represents the denitration activity duration of this calendar year accumulative total,

The annual denitration operating rate that η (∑ (∑ Di) m) expression SNCR technology is implemented,

$\mathrm{\η}\left(\underset{m=1}{\overset{12}{\mathrm{\Σ}}}{\left(\mathrm{\ΣDi}\right)}_m\right)=\left[\underset{m=1}{\overset{12}{\mathrm{\Σ}}}{\left(\mathrm{\ΣDi}\right)}_m\right]/\left(24\mathrm{mn}\right),$

Threshold value $\mathrm{\η}\left(\underset{m=1}{\overset{12}{\mathrm{\Σ}}}{\left(\mathrm{\ΣDi}\right)}_m\right)\min \≥35\%,$

η (c): the cement production system running rate, namely dore furnace and rotary kiln operation running rate require η (c) 〉=70%;

Through six months operation SNCR technology, obtain:

η (Di)=44%＜45%, undesirable,

η (∑ Di)=39%＜40%, undesirable,

$\mathrm{\&eta;}\left(\underset{m=1}{\overset{12}{\mathrm{\&Sigma;}}}{\left(\mathrm{\&Sigma;Di}\right)}_m\right)\min =28\%<35\%,$ It is undesirable,

At this moment accessed the record of identical time period cement production system running rate by middle control computer, η (c)=80%＞70%, made the prompting of " the SNCR The Application of Technology is on the low side " by middle control computer, by the Central Control Room managerial personnel production stability of cement kiln is carried out complete detection, and consider that the overall technology of SNCR is implemented environment to be detected.After the maintenance, discharge fault, store every data by middle control computer, continue the monitoring that next round is implemented the SNCR technology.

Claims (1)

1. cement mill SNCR NOx carrying capacity of environment is estimated and control method, it is characterized in that, be to reduce discharging in the carrying capacity of environment evaluation and computing machine on-line control system of NOx a cement mill SNCR SNCR technology that comprises central control computer, realize according to following steps successively:

Step (1), make up one be subjected to described in the carrying capacity of environment evaluation that reduces discharging NOx of the cement mill SNCR SNCR technology of control computer control with the computing machine on-line control system, comprising the storage unit of in the zone, cement mill, setting up and equipping following quantifying: the special ammonia water storage tank, the pure water storage tank, compressed air reservoir, in addition, also be provided with and comprise standby tank used for storing ammonia, and auxiliary equipment and equipment: spray gun, unload ammonia device, exhaust-valve, flexible hose and interface, the pipeline that connects each denitration module, lightning protection canopy and lightning protection facility and equipment, and to the tank car that transports ammoniacal liquor, fire fighting device, fire-water supply reserves working space, wherein:

The special ammonia water storage tank, storage is in order to the ammoniacal liquor NH of reducing NOx ₃H ₂O,

Pure water storage tank, storage be in order to cleaning denitration device and the pure water of weak ammonia when needing,

Compressed air reservoir, storage be in order to implementing the pressurized air of denitration operation,

Install at the coal powder injection pipe place of dore furnace in order to measuring the flowmeter of dore furnace coal consumption Mcoal (c), unit is in " kgce/t cl ", i.e. and " kilogram standard coal equivalent/ton grog ",

Install in order to measure the flowmeter of rotary kiln coal consumption amount Mcoal (k) at coal powder injection pipe place at rotary kiln, and unit is " kgce/t cl ", i.e. and " kilogram standard coal equivalent/ton grog ",

Wherein, utilize spray gun spray ammonia sign in the dore furnace to come into effect the SNCR technology,

Middle control computer initialization, set following parameter:

I: expression by middle control computer implement monitoring when i days an of calendar month, record n time altogether, n is numerically equal to the fate when individual calendar month, n ∈ 28,30,31},

Di: implemented the hourage of SNCR technology in i days, i.e. denitration activity duration of accumulative total in the same day,

η (Di): i days average denitration operating rates, η (Di)=Di/24, threshold value η (Di) min 〉=45%,

∑ Di: represent the adding and value of Di of m calendar month, i.e. expression is when an of that month denitration activity duration of calendar month accumulative total,

M represents a moon sequence number, m=1, and 2 ..., 12,

η (∑ Di) expression SNCR technology is implemented the hourly average denitration operating rate of the moon,

η(∑Di)=∑Di/(24n)，

Threshold value η (∑ Di) min 〉=40%,

M:m ∑ Di of ∑ (∑ Di) adds and value, represents the denitration activity duration of this calendar year accumulative total,

The annual denitration operating rate that η (∑ (∑ Di) m) expression SNCR technology is implemented,

$\mathrm{\&eta;}\left(\underset{m=1}{\overset{12}{\mathrm{\&Sigma;}}}{\left(\mathrm{\&Sigma;Di}\right)}_m\right)=\left[\underset{m=1}{\overset{12}{\mathrm{\&Sigma;}}}{\left(\mathrm{\&Sigma;Di}\right)}_m\right]/\left(24\mathrm{mn}\right),$

Threshold value $\mathrm{\&eta;}\left(\underset{m=1}{\overset{12}{\mathrm{\&Sigma;}}}{\left(\mathrm{\&Sigma;Di}\right)}_m\right)\min \&GreaterEqual;35\%,$

The coal consumption of described dore furnace and rotary kiln than the scope of ρ is:

1.5-10%≤ρ≤1.5+10%, the best is ρ=1.5,

$\mathrm{\&rho;}=\frac{\mathrm{Mcoal}\left(c\right)}{\mathrm{Mcoal}\left(k\right)}$

The scope of the temperature T calciner of dore furnace is: 850 ℃≤Tcalciner≤1050 ℃;

Step (2), various described storage element all are provided with the flow measurement device in order to the stoichiometric consumption amount,

Set: the lower limit of the real time capacity of ammoniacal liquor tank farm stock, pure water storage tank and compressed air reservoir is respectively 30% of its storage capacity, and described middle control computer is controlled ammoniacal liquor tank farm stock, pure water storage and pressurized air storage successively according to the following steps:

After the SNCR technology is implemented, at ammoniacal liquor consumption M _NH3H2OMore than or equal to 70%S ' _NH3H2OThe time, send the instruction that replenishes the ammoniacal liquor stock, S ' _NH3H2OBe the ammoniacal liquor max cap. of tank used for storing ammonia,

After the SNCR technology is implemented, at pure water consumption M _H2OMore than or equal to 70%S ' _H2OThe time, send the instruction that replenishes the pure water stock, S ' _H2OBe the pure water max cap. of pure water pot,

After the SNCR technology is implemented, at compressed air consumption M _AirMore than or equal to 70%S ' _AIRThe time, send the instruction that replenishes the pressurized air stock, S ' _AIRBe the pressurized air max cap. of compressed air tank,

The foundation system of tracing to the source is followed the trail of the raw materials used quality of implementing the SNCR technology,

(3), in middle control computer, set up following environmental impact quantizating index set { M _NH3H2O, M _H2O, M _Air, Mcoal (c), Mcoal (k), E _SNCR, TC _AIR, TC _H2O, TC _NH3H2O, M ⁰ _SO2, M _SO2, M ⁰ _CO, M _CO, M _Slip1, M _Slip2, M _Slip3, M ¹ _NOx}:

Mcoal (c): the coal consumption of dore furnace, require Mcoal (c)≤72kgce/t cl,

Mcoal (k): the coal consumption of rotary kiln, require Mcoal (k)≤50kgce/t cl,

E _SNCR: implement the used extra power consumption of SNCR technology, require E _SNCR≤ 10kWh/t cl,

TC _NH3H2O: the transported on trucks distance of special transportation ammoniacal liquor requires TC _NH3H2O≤100km,

TC _H2O: the transported on trucks distance of transportation pure water requires TC _H2O≤ 80km,

TC _AIR: transport compressed-air actuated transported on trucks distance, require TC _AIR≤ 80km,

M ⁰ _SO2: before implementing the SNCR technology at every turn, the SO in the suspended preheater C1 exit that records with the gas componant tester ₂Discharge capacity requires M ⁰ _SO2≤ 30mg SO ₂/ Nm ³,

M ⁰ _CO: before coming into effect the SNCR technology, record the CO discharge capacity in suspended preheater C1 exit with the gas componant tester at every turn, require M ⁰ _CO≤ 100mg CO/Nm ³,

M _SO2: after coming into effect the SNCR technology at every turn, after 5 minutes stabilization time, the SO in the suspended preheater C1 exit that records with the gas componant tester ₂Discharge capacity requires M _SO2≤ 25mg SO ₂/ Nm ³,

M _CO: after coming into effect the SNCR technology, after 5 minutes stabilization time, the CO discharge capacity in the suspended preheater C1 exit that records with the gas componant tester requires M at every turn _CO≤ 110mg CO/Nm ³,

M _Slip1: when unloading ammonia, unloading ammonia point with the amount of ammonia slip that the gas componant tester records, require M at every turn _Slip1≤ 15mgNH ₃/ Nm ³,

M _Slip2: after coming into effect the SNCR technology, after 5 minutes stabilization time, with the amount of ammonia slip that the gas componant tester records, require M in suspended preheater C1 exit at every turn _Slip2≤ 10mg NH ₃/ Nm ³,

M _Slip3: after coming into effect the SNCR technology, after 5 minutes stabilization time, with the amount of ammonia slip that the gas componant tester records, require M at spray ammonia mouth place at every turn _Slip3≤ 30mg NH ₃/ Nm ³,

M ¹ _NOx: after coming into effect the SNCR technology at every turn, after 5 minutes stabilization time, the NOx discharge capacity that records with the gas componant tester in suspended preheater C1 exit, with measured value all to be converted into NO ₂Meter requires M ¹ _NOx≤ 400mgNO ₂/ Nm ³,

Simultaneously, set up denitration efficiency quantizating index collection { η (Di), η (∑ Di), η (∑ (∑ Di) m, M ⁰ _NOx, M ¹ _NOx, Δ NOx, η (c), wherein:

M ⁰ _NOx: before coming into effect the SNCR technology at every turn, the NOx discharge capacity that records with the gas componant tester in suspended preheater C1 exit, with measured value all to be converted into NO ₂Meter,

Δ NOx: denitration rate, Δ NOx=(M ⁰ _NOx-M ¹ _NOx)/M ⁰ _NOx, work as M ⁰ _NOx≤ 500 o'clock, require Δ NOx 〉=55%,

η (c): the cement production system running rate, namely dore furnace and rotary kiln operation running rate require η (c) 〉=70%;

Step (4), middle control computer are monitored and each parameter of On-line Control in real time according to following steps:

Step (4.1), judgement are before coming into effect the SNCR technology, and whether following parameter value reaches following requirement simultaneously:

850℃≤Tcalciner≤1050℃，

Mcoal(c)≤72，

Mcoal(k)≤50，

1.5-10%≤ρ≤1.5+10%, and keep optimum value ρ=1.5 as far as possible,

M ⁰ _SO2≤30，

M ⁰ _CO≤100，

If: there is any one parameter not reach requirement, then adjusts the manufacturing parameter of dore furnace and rotary kiln, make its stable operation in setting range;

Step (4.2), judgement M ⁰ _NOx〉=600 are not,

If M ⁰ _NOx＜600, cement mill Central Control Room managerial personnel judge whether to implement the SNCR technology voluntarily according to this factory's production run cost and environmental protection requirement up to standard,

If M ⁰ _NOx〉=600, then start to implement the SNCR technology, and judge that following parameter is whether in threshold range:

M _Slip2≤10,

M _Slip3≤30,

M _SO2≤25,

M _CO≤110，

850℃≤Tcalciner≤1050℃，

Mcoal(c)≤72，

If when calciner temperature Tcalciner exceeds threshold value, then need in time stop to spray ammonia, in order to avoid cause waste ammoniacal liquor, and detect the coal consumption Mcoal (c) of dore furnace,

If Mcoal (c) exceeds threshold value, then stop to spray ammonia, whether artificial judgment must carry out the enforcement of SNCR technology this moment,

If M _SO2Exceed threshold value, then stop to spray ammonia, detect the flue stopping state,

If M _Slip2, M _COAll exceed threshold value, then stop to spray ammonia, and detect the dore furnace situation of leaking out,

If M _Slip3Exceed threshold value, then stop to spray ammonia, and detect the sealing of spray gun,

If M when unloading ammonia _Slip1Exceed threshold value, then wash the scene with clear water;

If E _SNCRExceed threshold value, then do detection to unloading ammonia, spray ammonia system and compressed air pump, the checkout facility aging conditions,

If cement mill kiln running rate greater than 70% situation under, (∑ (∑ Di) m is lower than threshold value for the operating rate of SNCR technology statistics η (Di), η (∑ Di) and η, then made the prompting of " the SNCR The Application of Technology is on the low side " by middle control computer, by the Central Control Room managerial personnel production stability of cement kiln is carried out complete detection, and consider that the overall technology of SNCR is implemented environment to be detected.

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