CN106570244A - One-dimensional simulation method for predicting cement kiln clinker quality - Google Patents

Abstract

The invention discloses a one-dimensional simulation method for predicting cement kiln clinker quality. The method comprises steps of (1) collecting relative information of a rotary kiln, to which clinker quality is to be predicted, (2), building a one-dimensional mathematic model in the cement rotary kiln, (3) collecting practical production part data of the cement rotary kiln as a border condition of the mathematic model, (4) calculating change conditions of smoke temperature, material temperature of the rotary kiln, a material bed height, wall surface temperature, material chemical components and clinker mineral contents along with the length change of the rotary kiln according to the one-dimensional mathematic model and the border condition, and (5) optimizing and adjusting the practical production operation according to the prediction result. According to the simulation result in the (4) step, the predicted clinker quality is contents of f-CaO, and C3S, C2S, C3A and C4AF. In the (2) step, the process innovatively provides a pulverized coal firing model and comprises a heat transmission module, a material bed motion model and a clinker mineral material chemical reaction model.

Description

A kind of one-dimensional emulation mode of prediction cement rotary kiln clinker quality

Technical field

The invention belongs to field of cement production, is related to a kind of one-dimensional emulation being predicted to cement rotary kiln clinker quality Method, the method is applied to the various cement calcinating process for being related to rotary kiln such as NSP rotary kiln, wet process rotary kiln.

Background technology

Cement industry is the important basic raw material industry of China, and China's cement output reaches 23.5 hundred million tons within 2015, is China's infrastructure construction and urban-rural integration development provide important leverage.Wherein, cement product quality directly influences phase Close the safety and Long-Term Properties of the infrastructure such as building.Evaluating the standard of cement quality includes fineness, insoluble matter, oxidation Content of magnesium, intensity of different larval instar etc..Wherein, cement different larval instar (including 3 days, 28 days) intensity is key index.Grog is forged It is then the direct factor for affecting cement different larval instar intensity to burn quality.

Grog is the intermediate product of cement production process.In existing New Type Dry-process Cement Production, prepare according to a certain percentage Raw material through processes such as grinding, homogenizing, be fed in preheater, through preheater heat exchange after, decomposed in dore furnace, Resolution ratio 95% or so hot raw material subsequently into the processes such as solid state reaction, liquid-phase sintering are carried out in rotary kiln, calcined Grog is dropped in cooler with rotary kiln operating and quickly cooled down, and the grog for going out cooler enters storage in clinker warehouse, is used in combination In follow-up cement pulverizing course.During this, rotary kiln is the crucial Thermal Equipment of clinker burning quality, four kinds of mineral of grog Tricalcium silicate (hereinafter referred to as " C3S "), dicalcium silicate (hereinafter referred to as " C2S "), tricalcium aluminate (hereinafter referred to as " C3A "), ferrum aluminum The formation of sour four calcium (hereinafter referred to as " C4AF ") occurs all in rotary kiln, and these four mineral are the passes for affecting clinker strength development Key factor.Because directly these four mineral cannot be carried out with accurate quantitative analyses, cement production enterprise generally with free calcium oxide (with Lower abbreviation " f-CaO ") content to be characterizing clinker burning process.In simple terms, if raw material chemical composition is identical, f-CaO contents Higher to show that clinker burning quality is poorer, f-CaO contents are lower to show that clinker burning quality is better.Therefore, clinker burning is characterized The parameter of quality includes the content and f-CaO contents of tetra- kinds of mineral of C3S, C2S, C3A, C4AF.

At present, with reference to national common portland cement national standard (GB 175-2007), cement production enterprise is generally using chemistry Analysis method (glycerol-Ethanol Method) is detected to f-CaO contents in grog, using fluorescence analyser or chemical analysis method pair Calcium oxide (CaO), silicon oxide (SiO2), aluminium oxide (Al2O3), ferrum oxide (Fe2O3) content are measured in grog, and according to Related conversion method, calculates C3S, C2S, C3A, C4AF mineral content.Said method such as is related to sample, grinds, detects, calculating at the stream Journey, process is complex.The general each two hour of cement production enterprise or longer time carry out the test of a f-CaO content, per four Individual hour or longer time carry out the test of a grog chemical composition and then are converted into clinker mineral composition.At above-mentioned interval It is interior, completely clinker burning is adjusted accordingly by the experience of operator, clinker burning quality is heavily dependent on The personal experience of operator and responsibility.For this purpose, exploitation is a kind of weighing very much to the method that clinker burning quality carries out real-time estimate Will.

Set up a kind of method being predicted to clinker quality that rotary kiln clinker calcining model is that people more early attempt.Return Rotary kiln calcination process includes the processes such as burning, heat transfer, mass transfer, momentum transmission, chemical reaction, and correlation model is complex.Previous generation Record the fifties, H.Kramers, P.Croockewit (The Passage of Granular Solids Through Inclined Rotary Kilns, 1952) elaborate the motion model of material in rotary kiln；Allan Sass(Simulation Of the Heat Transfer Phenomena in a Rotary Kiln, 1967) establish the heat transfer in cement rotary kiln The processes such as radiation, convection current, conduction between model, including gas phase, material, wall, environment；Spang III(A Dynamic Model of a Cement Kiln, 1972) establish the dynamic model of cement rotary kiln, consider simultaneously on the basis of heat transfer Coal dust firing and chemical reaction process；(the Heat Transfer from Flames in a such as J.P.Gorog, T.N.Adams Rotary Kiln, 1983) illustrate the heat transfer model in length, thermal discharge and the rotary kiln of flame；Afterwards with calculating The development of hydrodynamics (CFD), using CFD model to simulate three-dimensional condition under in rotary kiln the process such as flowing, heat transfer become (the CFD Predictions for Cement Kiln Including Flame such as the emphasis of research, Mastorakos Modeling, Heat Transfer and Clinker Chemistry, 1999) using the gas phase flowing in CFD, heat transfer mould Type, and kiln cylinder body temperature etc. is predicted with reference to mineral formation model；The country is also related to CFD and applies in cement rotary kiln Many research, including the colleges and universities such as Wuhan University of Technology, the Central China University of Science and Technology have more achievement in research.Hereafter, it is more multiple Miscellaneous One dimensional Mathematical Model is established, such as Kaustubh S (Modeling of Rotary Cement Kilns: Applications to Reduction in Energy Consumption, 2006) considered heat transfer, material movement, Coal dust firing, chemical reaction, grog skinning etc., acquired results also more coincide with actual；Except this, it is considered to the three-dimensional artificial such as CFD Cannot be to expecting that bed motion is simulated, external part is studied by three-dimensional visual simulation in combination with one-dimensional model, or considers simulation As a result maximum gas temperature is set as unknown number by accuracy, and is adjusted accordingly according to clinker burning quality and made it with reality Situation matches, such as Christopher Csernyei (Numerical Modeling of a Rotary Cement Kiln With Improvements to Shell Cooling, 2016) according to clinker mineral reaction adjustment rotary kiln gas peak value temperature Degree, and assume that change of the gas temperature in rotary kiln turns to linear change etc..

Generally speaking, above-mentioned cement rotary kiln model includes two big class, i.e. one-dimensional model and threedimensional model, and one-dimensional model is neglected Slightly gas, material, wall only consider the change on axial direction in the difference for radially and circumferentially going up in rotary kiln；Threedimensional model is usual By means of existing software, such as Fluent, CFX is calculated.However, above-mentioned model is applied to exist in practice necessarily asking Topic.

For one-dimensional model, the goodness of fit of coal dust firing model and practical situation be affect analog result it is important because One of element.Domestic and international following several models of primary study：1. it is based on length of flame empirical formula, it is assumed that coal dust firing is put The heat for going out is uniformly distributed in the length；2. assume that combustion reaction is controlled by diffusion, is entered based on diffusion law to burning degree Row is solved, and assumes that combustion heat release amount changes with extent of reaction direct proportion；3. assume pulverized coal particle burning include heating, volatilize, The stages such as burning, cooling, and mathematical formulae etc. is given respectively for each stage.Except this, the movement velocity and rail of pulverized coal particle Mark directly affects the time of staying of the coal dust in rotary kiln, and its heat release situation, existing pulverized coal particle motion mould are affected then Formula mainly includes following several：1. assume that pulverized coal particle movement velocity is equal with vapor phase movement speed；2. by exponential form Empirical equation expression etc..But under practical situation coal dust by multi-passage coal injection pipe ejection after axle stream wind, Whirl deposite tank effect under Forms of motion it is extremely complex, never only one-dimensional problem.Except this, existing One dimensional Mathematical Model assumes the thin of pulverized coal particle Degree, Industrial Analysis keep constant, and the fineness of coal dust, moisture, volatile matter content etc. are all in change under practical situation.Cause This, the existing model with regard to coal dust firing cannot match with practical situation.

For threedimensional model, although can consider compound movement of the pulverized coal particle under the effect of coal injection pipe each air channel with Combustion type, but there are two subject matters, one is cannot to need with material bed motion to expecting that bed motion is directly stated Dimension module combines, and which increases the complexity of model；Two is that threedimensional model needs to carry out rotary kiln the process such as stress and strain model, Complex operation, calculating time are longer, and cannot be used directly for in-circuit emulation calculating down at this stage, are only used for offline interpretation of result Deng.

As the above analysis, due in rotary kiln clinker burning process it is extremely complex, influence factor is more, existing number Learning model cannot carry out accurate description to real process.Here, the present invention proposes a kind of simple, effective rotary kiln clinker calcining One dimensional Mathematical Model, innovation and application coal dust firing model, is applied to the prediction of cement rotary kiln clinker quality, as a result with Practical situation matches.Contribute to realizing the on-line prediction of clinker burning quality, and then instruct the operation of rotary kiln.

The content of the invention

The present invention proposes a kind of simple, effectively prediction cement rotary kiln clinker burning quality emulation mode, by building The One dimensional Mathematical Model of heat transfer, material bed motion, coal dust firing and clinker mineral reaction in vertical rotary kiln, to rotary kiln clinker quality It is predicted, practical condition of the coal dust firing one-dimensional model used based on cement production enterprise improves the degree of accuracy of simulation, can Solve the problems, such as that existing rotary kiln coal dust firing One dimensional Mathematical Model is larger with actual deviation.

For achieving the above object, technical scheme is as follows：

A kind of one-dimensional emulation mode of prediction cement rotary kiln clinker burning quality, comprises the steps：

(1) relevant information of the rotary kiln of prediction clinker burning quality, including rotary kiln length, external diameter, fire resisting are intended in collection Insulation material thickness, gradient, rotating speed etc. are used as the basis for setting up related rotary kiln mathematical model；

(2) One dimensional Mathematical Model set up in cement rotary kiln, during being somebody's turn to do coal dust firing model is innovatively proposed, And including heat transfer model, material bed motion model and clinker mineral Chemical Reaction Model, respectively to simulate gas phase in rotary kiln, thing Material, the heat and mass situation between kiln wall and environment, material movement situation in rotary kiln, coal dust firing situation and grog in kiln Mineral chemistry course of reaction；

(3) gather cement rotary kiln actual production partial data, including feeding capacity, feed coal amount, enter kiln raw material temperature, enter kiln The boundary condition of raw material chemical constituent, secondary wind temperature, rotary kiln rotating speed, kliner coating length as mathematical model；

(4) according to the One dimensional Mathematical Model and boundary condition, be calculated flue-gas temperature in rotary kiln, temperature of charge, Expect the situation of change with rotary kiln length such as bed height, wall surface temperature, material chemical composition, clinker minerals content；

(5) simulation result in step (4), the clinker quality predicted for kiln hood position f-CaO contents and C3S, C2S, C3A, C4AF mineral content, according to being predicted the outcome actual production operation is optimized and is adjusted.

Further, the heat transfer model in described step (2) is as follows：

Wherein, T_s、T_g、T_w、T_i、T_oThe temperature of material, gas, internal face, outside wall surface and environment, K are represented respectively；m_s、m_g The quality of the gentle body of material, kg/s are represented respectively；Cp_s、Cp_gThe specific heat capacity of the gentle body of material, J/ (kgK) are represented respectively；ε_s、 ε_g、ε_wThe radiation coefficient of material, gas and wall is represented respectively；α_gFor the absorbance of gas；h_cgs、h_cgw、h_cws、h_cioRespectively Heat convection system between gas and material, between gas and internal face, between internal face and material, between outside wall surface and environment Number, J/ (m²·K)；Q_cAnd Q_fIt is respectively clinker mineral forming process exothermic heat of reaction amount and coal dust firing thermal discharge, J；A_rgs、A_cgs、 A_rgw、A_cgw、A_rws、A_cws、A_iRadiation heat transfer area, the heat convection face between gas and solid respectively between gas and solid Product, the radiation heat transfer area between gas and internal face, the heat convection area between gas and internal face, internal face and solid Between radiation heat transfer area, the heat convection area between internal face and solid and outer sectional area, m²；k_rFor refractory material Heat conductivity, W/ (mK)；σ is Stefan-Boltzmann constant, and its value is 5.676 × 10^-8W/(m²·K⁴)；R is rotary kiln The radius of internal diameter, m；e_rFor the thickness of refractory material, m；Ω is the space factor relevant with kiln internal face and material bed；X is revolution The axial distance of kiln, m.

Further, the material bed motion model in described step (2) is as follows：

Wherein, the material bed height that h is formed for material, m；u_sFor the movement velocity of material, m/s；α is rotary kiln gradient, rad；β be rotary kiln in material angle of repose, rad；φ_vFor the volume flow of material, m3/s；N be rotary kiln rotating speed, rad/s； K is the characteristic coefficient for expecting bed motion.

Further, the coal dust firing model in described step (2) is as follows：

Think in cement rotary kiln, the length of flame is kliner coating length.Coal dust in the range of the length of flame, after normalization Granular mass meets equation below：

C_f=e^a(60-x)+b

Wherein, C_fFor the quality of pc after normalization；A, b are the constant in model, are determined according to such as downstream condition：

(i.e. grog exit) thinks C at kiln hood_f=1；According to the kliner coating length for being gathered, it is believed that the C at the position_f Ash in=coal dust；The position being located from kiln tail (i.e. hot raw material enter at kiln) to kliner coating length, it is believed that C_fConsistently equal to coal dust In ash.

According to pulverized coal particle mass change formula, it is believed that at corresponding x, coal dust thermal discharge is as follows：

Wherein, m_fCoal amount, kg/s are fed for kiln hood；ΔH_fFor the low level thermal discharge of coal dust Industrial Analysis, J/kg.

Further, the clinker mineral formation model in described step (2) is as follows：

Wherein, Ca2O3, SiO2, Al2O3, Fe2O3, CaO are respectively Calcium Carbonate in raw material, silicon oxide, aluminium oxide, oxidation The mass fraction of ferrum, calcium oxide, %；C2S, C3A, C4AF, C3S are respectively dicalcium silicate in grog, tricalcium aluminate, ferrum aluminic acid four The mass fraction of calcium, tricalcium silicate, %；M_CaCO3、M_SiO2、M_Al2O3、M_Fe2O3、M_CaO、M_C2S、M_C3A、M_C4AF、M_C3SIt is respectively carbonic acid Calcium, silicon oxide, aluminium oxide, ferrum oxide, calcium oxide, dicalcium silicate, tricalcium aluminate, tetra calcium aluminoferrite, mole matter of tricalcium silicate Amount, g/mol；k_CaCO3、k_C2S、k_C3A、k_C4AF、k_C3SIt is respectively Calcium Carbonate, dicalcium silicate, tricalcium aluminate, tetra calcium aluminoferrite, silicic acid The speed that DFP is reacted, 1/s.

Further, according to mineral reaction process, reaction liberated heat is as follows：

Wherein, Δ H_CaCO3、ΔH_C2S、ΔH_C3A、ΔH_C4AF、ΔH_C3SRespectively Calcium Carbonate, dicalcium silicate, tricalcium aluminate, ferrum The reaction heat that the calcium of aluminic acid four, tricalcium silicate are reacted, J/kg.

Further, the reaction rate expression formula of each reaction is as follows：

k_j=A_jexp(-E_j/RT_s)；

Wherein, A_jTo react j pre-exponential factors, s-1；E_jTo react the activation energy of j, J/ (molK)；J then represents carbonic acid Calcium, dicalcium silicate, tricalcium aluminate, tetra calcium aluminoferrite, five reactions of tricalcium silicate.

Beneficial effect

Compared to existing technology, the invention has the advantages that：

(1) accuracy

Cement rotary kiln One dimensional Mathematical Model proposed by the present invention includes heat transfer model, material movement model, coal dust firing Model, mineral chemistry reaction model, cover all physics chemistry process carried out in rotary kiln substantially；Except this, the present invention is created The property made proposes the coal dust firing model for being applied to cement rotary kiln, and based on Chinese scholars research coal dust in rotary kiln is thought The theoretical knowledge that thermal discharge is exponentially distributed, with reference to kliner coating length in each cement production enterprise rotary kiln, i.e. coal dust firing fire Flame length is identical with vapor phase movement speed so as to abandon the uniform heat release of coal dust, coal dust movement velocity in original hypothesis rotary kiln Deng it is assumed that substantially increasing the accuracy of result.

(2) practicality

Coal dust firing model proposed by the invention also has very strong practicality in addition to higher accuracy, with Tradition is controlled based on combustion reaction by diffusion, it is considered to the model such as point phase process such as pulverized coal particle heating, volatilization, burning, cooling Compare, this model is more succinct；Meanwhile, compared with calculating grid very many required by cement rotary kiln threedimensional model is calculated, One dimensional Mathematical Model proposed by the present invention has more practicality.

Description of the drawings

Fig. 1 is embodiment result of calculation rotary kiln one-dimension temperature field schematic diagram；

Fig. 2 is embodiment result of calculation coal dust firing thermal discharge change schematic diagram；

Fig. 3 is embodiment result of calculation rotary kiln clinker chemical composition change schematic diagram；

Fig. 4 is embodiment result of calculation rotary kiln clinker mineralogical composition change schematic diagram.

Specific embodiment

The solution of the present invention is：A kind of one-dimensional emulation mode of prediction cement rotary kiln clinker burning quality is proposed, it is described Emulation mode comprise the steps：

(1) relevant information of the rotary kiln of prediction clinker burning quality, including rotary kiln length, external diameter, fire resisting are intended in collection Insulation material thickness, gradient, rotating speed etc. are used as the basis for setting up related rotary kiln mathematical model.

(2) One dimensional Mathematical Model set up in cement rotary kiln, during being somebody's turn to do coal dust firing model is innovatively proposed, And including heat transfer model, material bed motion model and clinker mineral Chemical Reaction Model, respectively to simulate gas phase in rotary kiln, thing Material, the heat and mass situation between kiln wall (refractory insulating layer) and environment, material movement situation in rotary kiln, coal dust combustion in kiln Burning situation and clinker mineral chemical reaction process etc.；

(3) gather cement rotary kiln actual production partial data, including feeding capacity, feed coal amount (rotary kiln), enter kiln raw material Temperature, enter kiln raw material chemical constituent, secondary wind temperature, rotary kiln rotating speed, kliner coating length as the boundary condition of mathematical model；

(4) according to the One dimensional Mathematical Model and boundary condition, be calculated flue-gas temperature in rotary kiln, temperature of charge, Expect the situation of change with rotary kiln length such as bed height, wall surface temperature, material chemical composition, clinker minerals content；

(5) simulation result in step (4), the clinker quality predicted is the f- of kiln hood (grog outlet) position CaO content and C3S, C2S, C3A, C4AF mineral content, according to being predicted the outcome actual production operation is optimized and is adjusted.

According to emulation mode of the present invention, the heat transfer model in described step (2) is as follows：

Wherein, T_s、T_g、T_w、T_i、T_oThe temperature of material, gas, internal face, outside wall surface and environment, K are represented respectively；m_s、m_g The quality of the gentle body of material, kg/s are represented respectively；Cp_s、Cp_gThe specific heat capacity of the gentle body of material, J/ (kgK) are represented respectively；ε_s、 ε_g、ε_wThe radiation coefficient of material, gas and wall is represented respectively；α_gFor the absorbance of gas；h_cgs、h_cgw、h_cws、h_cioRespectively Heat convection system between gas and material, between gas and internal face, between internal face and material, between outside wall surface and environment Number, J/ (m²·K)；Q_cAnd Q_fIt is respectively clinker mineral forming process exothermic heat of reaction amount and coal dust firing thermal discharge, J；A_rgs、A_cgs、 A_rgw、A_cgw、A_rws、A_cws、A_iRadiation heat transfer area, the heat convection face between gas and solid respectively between gas and solid Product, the radiation heat transfer area between gas and internal face, the heat convection area between gas and internal face, internal face and solid Between radiation heat transfer area, the heat convection area between internal face and solid and outer sectional area, m²；k_rFor refractory material Heat conductivity, W/ (mK)；σ is Stefan-Boltzmann constant, and its value is 5.676 × 10^-8W/(m²·K⁴)；R is rotary kiln The radius of internal diameter, m；e_rFor the thickness of refractory material, m；Ω is the space factor relevant with kiln internal face and material bed；X is revolution The axial distance of kiln, m.

According to emulation mode of the present invention, the material bed motion model in described step (2) is as follows：

Wherein, the material bed height that h is formed for material, m；u_sFor the movement velocity of material, m/s；α is rotary kiln gradient, rad；β be rotary kiln in material angle of repose, rad；φ_vFor the volume flow of material, m3/s；N be rotary kiln rotating speed, rad/s； K is the characteristic coefficient for expecting bed motion.

According to emulation mode of the present invention, the coal dust firing model in described step (2) is as follows：

Think in cement rotary kiln, the length of flame is kliner coating length.Coal dust in the range of the length of flame, after normalization Granular mass meets equation below：

C_f=e^a(60-x)+b

Wherein, C_fFor the quality of pc after normalization；A, b are the constant in model, are determined according to such as downstream condition：

(i.e. grog exit) thinks C at kiln hood_f=1；According to the kliner coating length for being gathered, it is believed that the C at the position_f Ash in=coal dust；The position being located from kiln tail (i.e. hot raw material enter at kiln) to kliner coating length, it is believed that C_fConsistently equal to coal dust In ash.

According to pulverized coal particle mass change formula, it is believed that at corresponding x, coal dust thermal discharge is as follows：

Wherein, m_fCoal amount, kg/s are fed for kiln hood；ΔH_fFor the low level thermal discharge of coal dust Industrial Analysis, J/kg.

According to emulation mode of the present invention, it is as follows that the clinker mineral in described step (2) forms model：

Wherein, Ca2O3, SiO2, Al2O3, Fe2O3, CaO are respectively Calcium Carbonate in raw material, silicon oxide, aluminium oxide, oxidation The mass fraction of ferrum, calcium oxide, %；C2S, C3A, C4AF, C3S are respectively dicalcium silicate in grog, tricalcium aluminate, ferrum aluminic acid four The mass fraction of calcium, tricalcium silicate, %；M_CaCO3、M_SiO2、M_Al2O3、M_Fe2O3、M_CaO、M_C2S、M_C3A、M_C4AF、M_C3SIt is respectively carbonic acid Calcium, silicon oxide, aluminium oxide, ferrum oxide, calcium oxide, dicalcium silicate, tricalcium aluminate, tetra calcium aluminoferrite, mole matter of tricalcium silicate Amount, g/mol；k_CaCO3、k_C2S、k_C3A、k_C4AF、k_C3SIt is respectively Calcium Carbonate, dicalcium silicate, tricalcium aluminate, tetra calcium aluminoferrite, silicic acid The speed that DFP is reacted, 1/s.

According to mineral reaction process, reaction liberated heat is as follows：

Wherein, Δ H_CaCO3、ΔH_C2S、ΔH_C3A、ΔH_C4AF、ΔH_C3SRespectively Calcium Carbonate, dicalcium silicate, tricalcium aluminate, ferrum The reaction heat that the calcium of aluminic acid four, tricalcium silicate are reacted, J/kg.

The reaction rate expression formula of each reaction is as follows：

k_j=A_jexp(-E_j/RT_s)

Wherein, A_jTo react j pre-exponential factors, s-1；E_jTo react the activation energy of j, J/ (molK)；J then represents carbonic acid Calcium, dicalcium silicate, tricalcium aluminate, tetra calcium aluminoferrite, five reactions of tricalcium silicate.

The A of five reactions_jAnd E_jDifference is as shown in the table.

Sequentially	Reaction	Aj	Ej	ΔHj
					1	CaCO3=CaO+CO2	1.18E+06	1.85E+05	1.78E+06
2	2CaO+SiO2=C2S	1E+07	2.34E+05	-1.124E+06
					3	C2S+CaO=C3S	1E+08	4.2E+05	8.01E+04
4	3CaO+Al2O3=C3A	1E+08	3.1E+05	-4.34E+04
					5	C3A+Fe2O3+CaO=C4AF	1E+08	3.3E+05	-2.278E+05

Above-mentioned model, especially coal dust firing model, with reference to the practical situation of each cement production enterprise, change to quality of pc Predicted with the change of thermal discharge.In conjunction with heat transfer model, material bed motion model and mineral reaction model, realize to revolution Gas phase, material, internal face, outside wall surface temperature changing trend in kiln, material movement speed, the time of staying, height change become in kiln Gesture, quality of pc and thermal discharge variation tendency, the analog simulation such as grog chemical composition and mineral content variation tendency.

Boundary condition in the present invention involved by all model calculating process all can be by Site Detection acquisition, part Model parameter, then be empirical.All model equations are all the differential equations, belong to process simulation model, refer to variable more Content it is relevant with concrete physical location.

Embodiment

Domestic certain 2500 ton day cement clinker production line, capital equipment and technological parameter, boundary condition it is as shown in table 1.Base In parameter shown in table 1 and emulation mode calculation procedure set forth in the present invention, using mathematical model set forth in the present invention, calculate The production line rotary kiln one-dimension temperature field distribution schematic diagram, coal dust firing thermal discharge change schematic diagram, rotary kiln clinker chemistry into Divide change schematic diagram and rotary kiln clinker mineralogical composition change schematic diagram, respectively as shown in Figure 1 to 4.Respectively and actual test As a result it is compared, is verified with the accuracy to institute's procedures set forth of the present invention.

The embodiment basic parameter of table 1 and boundary condition.

Fig. 1 is embodiment result of calculation rotary kiln one-dimension temperature field schematic diagram.Calculate parameters obtained and actually detected parameter Contrast it is as shown in table 2.As shown in Table 2, embodiment tries to achieve temperature with the error of actual value within 2%, with very High accuracy.This shows the accuracy of the change schematic diagram of coal dust firing thermal discharge shown in Fig. 2 indirectly, illustrates proposed by the invention Coal dust firing model have higher accuracy.

The embodiment of table 2 calculates the contrast of kiln temperature and measured temperature

Parameter	Value of calculation/K	Actual value/K	Difference
				Kiln tail gas temperature	1313	1330	17
Kiln hood temperature of charge	1697	1703	6
				Outside wall surface maximum temperature	489.8	493	3.2

Fig. 3 is embodiment result of calculation rotary kiln clinker chemical composition change trend, is primarily upon calcium oxide in kiln hood The value of free calcium oxide in content, i.e. grog；Become with reference to the change of embodiment illustrated in fig. 4 result of calculation rotary kiln clinker mineralogical composition Gesture, is primarily upon content of four mineral in kiln hood.The value of calculation of above-mentioned five parameters is as shown in table 3 with actual test value.By Table 3 understands that the value of calculation of five parameters of above-mentioned sign cement rotary kiln clinker quality with actual value closely, shows described The accuracy of model, the method formed based on above-mentioned model is fully available for the Accurate Prediction of clinker quality.

The contrast of the embodiment result of calculation clinker quality value of calculation of table 3 and actual value.

Parameter	Value of calculation/%	Actual value/%	Difference/%
				Free calcium oxide	1.196	1.10	0.096
Tricalcium silicate	54.77	55.10	0.33
				Dicalcium silicate	19.58	19.82	0.24
Aluminum calculates DFP	7.883	7.87	0.013
				Tetra calcium aluminoferrite	10.59	10.58	0.01

Claims (7)

1. a kind of one-dimensional emulation mode of prediction cement rotary kiln clinker burning quality, comprises the steps：

(1) relevant information of the rotary kiln of prediction clinker burning quality, including rotary kiln length, external diameter, fire resistant heat preserving are intended in collection Material thickness, gradient, rotating speed etc. are used as the basis for setting up related rotary kiln mathematical model；

(2) One dimensional Mathematical Model set up in cement rotary kiln, during being somebody's turn to do coal dust firing model is innovatively proposed, and is wrapped Include heat transfer model, material bed motion model and clinker mineral Chemical Reaction Model, respectively to simulate gas phase in rotary kiln, material, Heat and mass situation between kiln wall and environment, material movement situation in rotary kiln, coal dust firing situation and grog ore deposit in kiln Thing chemical reaction process；

(3) gather cement rotary kiln actual production partial data, including feeding capacity, feed coal amount, enter kiln raw material temperature, enter kiln raw material The boundary condition of chemical constituent, secondary wind temperature, rotary kiln rotating speed, kliner coating length as mathematical model；

(4) according to the One dimensional Mathematical Model and boundary condition, flue-gas temperature in rotary kiln, temperature of charge, material bed are calculated Highly, wall surface temperature, material chemical composition, clinker minerals content etc. with rotary kiln length situation of change；

(5) simulation result in step (4), the clinker quality predicted for kiln hood position f-CaO contents and C3S, C2S, C3A, C4AF mineral content, according to being predicted the outcome actual production operation is optimized and is adjusted.

2. the one-dimensional emulation mode of cement rotary kiln clinker burning quality is predicted as claimed in claim 1, it is characterised in that：

Heat transfer model in described step (2) is as follows：

$\begin{array}{c}{m}_s{\mathrm{Cp}}_s\frac{{\mathrm{dT}}_s}{dx}={\mathrm{\σA}}_{rgs}\left({\mathrm{\ϵ}}_s+1\right)\left(\frac{{\mathrm{\ϵ}}_g{T_g}^4-{\mathrm{\α}}_g{T_s}^4}{2}\right)+h_{cgs}{A}_{cgs}\left(T_g-T_s\right)+{\mathrm{\σA}}_{rws}{\mathrm{\ϵ}}_w{\mathrm{\ϵ}}_s\left(1-{\mathrm{\ϵ}}_g\right)\mathrm{\Ω}\left({T_w}^4-{T_s}^4\right)\\ +h_{cws}{A}_{cws}\left(T_w-T_s\right)+Q_c\end{array};$

$\begin{array}{c}{m}_g{\mathrm{Cp}}_g\frac{{\mathrm{dT}}_g}{dx}=-{\mathrm{\σA}}_{rgs}\left({\mathrm{\ϵ}}_s+1\right)\left(\frac{{\mathrm{\ϵ}}_g{T_g}^4-{\mathrm{\α}}_g{T_s}^4}{2}\right)-h_{cgs}{A}_{cgs}\left(T_g-T_s\right)-{\mathrm{\σA}}_{rgw}\left({\mathrm{\ϵ}}_w+1\right)\left(\frac{{\mathrm{\ϵ}}_g{T_g}^4-{\mathrm{\α}}_g{T_w}^4}{2}\right)\\ -h_{cgw}{A}_{cgw}\left(T_g-T_w\right)+Q_f\end{array};$

$\begin{array}{c}{\mathrm{\σA}}_{rws}{\mathrm{\ϵ}}_w{\mathrm{\ϵ}}_s\left(1-{\mathrm{\ϵ}}_g\right)\mathrm{\Ω}\left({T_w}^4-{T_s}^4\right)+h_{cws}{A}_{cws}\left(T_w-T_s\right)+{\mathrm{\σA}}_{rgw}\left({\mathrm{\ϵ}}_w+1\right)\left(\frac{{\mathrm{\ϵ}}_g{T_g}^4-{\mathrm{\α}}_g{T_w}^4}{2}\right)+h_{cgw}{A}_{cgw}\left(T_g-T_w\right)\\ =\frac{2{\mathrm{\πk}}_r}{\ln \left(\frac{R+e_r}{R}\right)}\left(T_w-T_i\right)\end{array};$

$\frac{2{\mathrm{\πk}}_r}{\ln \left(\frac{R+e_r}{R}\right)}(T_w-T_i)=h_{ci0}{A}_i(T_i-T_o)+{\mathrm{\σA}}_i{\mathrm{\ϵ}}_w({T_i}^4-{T_o}^4);$

Wherein, T_s、T_g、T_w、T_i、T_oThe temperature of material, gas, internal face, outside wall surface and environment, K are represented respectively；m_s、m_gDifference table Show the quality of material and gas, kg/s；Cp_s、Cp_gThe specific heat capacity of the gentle body of material, J/ (kgK) are represented respectively；ε_s、ε_g、ε_wPoint Not Biao Shi material, gas and wall radiation coefficient；α_gFor the absorbance of gas；h_cgs、h_cgw、h_cws、h_cioRespectively gas and Convection transfer rate between material, between gas and internal face, between internal face and material, between outside wall surface and environment, J/ (m²·K)；Q_cAnd Q_fIt is respectively clinker mineral forming process exothermic heat of reaction amount and coal dust firing thermal discharge, J；A_rgs、A_cgs、A_rgw、 A_cgw、A_rws、A_cws、A_iRadiation heat transfer area, the heat convection area between gas and solid, gas respectively between gas and solid Radiation heat transfer area between body and internal face, the heat convection area between gas and internal face, between internal face and solid Radiation heat transfer area, the heat convection area between internal face and solid and outer sectional area, m²；k_rFor the heat conduction of refractory material Coefficient, W/ (mK)；σ is Stefan-Boltzmann constant, and its value is 5.676 × 10^-8W/(m²·K⁴)；R is rotary kiln internal diameter Radius, m；e_rFor the thickness of refractory material, m；Ω is the space factor relevant with kiln internal face and material bed；X is rotary kiln Axial distance, m.

3. the one-dimensional emulation mode of cement rotary kiln clinker burning quality is predicted as claimed in claim 1, it is characterised in that：

Material bed motion model in described step (2) is as follows：

$\frac{dh}{dx}=tan\mathrm{\β}\[\frac{tan\mathrm{\α}}{\sin \mathrm{\β}}-\frac{3{\mathrm{\φ}}_v}{4{\mathrm{\πnR}}^3}{(\frac{2h}{R}-\frac{h^2}{R^2})}^{-3/2}\];$

$u_s=K\frac{{\mathrm{\αR}}^2}{h^{2}cos\mathrm{\β}+\left(2h\sqrt{2hR-h^2}\right)\sin \mathrm{\β}};$

Wherein, the material bed height that h is formed for material, m；u_sFor the movement velocity of material, m/s；α be rotary kiln gradient, rad；β is The angle of repose of material, rad in rotary kiln；φ_vFor the volume flow of material, m3/s；N be rotary kiln rotating speed, rad/s；K is material bed Motion characteristics coefficient.

4. the one-dimensional emulation mode of cement rotary kiln clinker burning quality is predicted as claimed in claim 1, it is characterised in that：

Coal dust firing model in described step (2) is as follows：

Think in cement rotary kiln, the length of flame is kliner coating length.Pulverized coal particle in the range of the length of flame, after normalization Quality meets equation below：

C_f=e^a(60-x)+b

Wherein, C_fFor the quality of pc after normalization；A, b are the constant in model, are determined according to such as downstream condition：

(i.e. grog exit) thinks C at kiln hood_f=1；According to the kliner coating length for being gathered, it is believed that the C at the position_f=coal Ash in powder；The position being located from kiln tail (i.e. hot raw material enter at kiln) to kliner coating length, it is believed that C_fConsistently equal in coal dust Ash.

According to pulverized coal particle mass change formula, it is believed that at corresponding x, coal dust thermal discharge is as follows：

$Q_f=m_f{\mathrm{\ΔH}}_f\frac{{\mathrm{dC}}_f}{dx}$

Wherein, m_fCoal amount, kg/s are fed for kiln hood；ΔH_fFor the low level thermal discharge of coal dust Industrial Analysis, J/kg.

5. the one-dimensional emulation mode of cement rotary kiln clinker burning quality is predicted as claimed in claim 1, it is characterised in that：

It is as follows that clinker mineral in described step (2) forms model：

$\frac{\∂CaCO3}{\∂x}=\[-k_{CaCO3}\left(CaCO3\right)M_{CaCO3}\]/u_s;$

$\frac{\∂SiO2}{\∂x}=\[-k_{C2S}\left(SiO2\right){\left(CaO\right)}^2{M}_{SiO2}\]/u_s;$

$\frac{\∂Al2O3}{\∂x}=\[-k_{C3A}\left(Al2O3\right){\left(CaO\right)}^3{M}_{Al2O3}\]/u_s;$

$\frac{\∂Fe2O3}{\∂x}=\[-k_{C4AF}\left(C3A\right)\left(Fe2O3\right)\left(CaO\right)M_{Fe2O3}\]/u_s;$

$\begin{array}{c}\frac{\∂CaO}{\∂x}=\[k_{CaCO3}\left(CaCO3\right)M_{CaO}-k_{C3S}\left(CaO\right)\left(C2S\right)M_{CaO}-2k_{C2S}\left(SiO2\right){\left(CaO\right)}^2{M}_{CaO}\\ -3k_{C3A}{\left(CaO\right)}^3\left(Al2O3\right)M_{CaO}-k_{C4AF}\left(C3A\right)\left(CaO\right)\left(Fe2O3\right)M_{CaO}\]/u_s\end{array};$

$\frac{\∂C2S}{\∂x}=\[k_{C2S}\left(SiO2\right){\left(CaO\right)}^2{M}_{C2S}-k_{C3S}\left(C2S\right)\left(CaO\right)M_{C2S}\]/u_s;$

$\frac{\∂C3A}{\∂x}=\[k_{C3A}\left(Al2O3\right){\left(CaO\right)}^3{M}_{Al2O3}\]/u_s;$

$\frac{\∂C4AF}{\∂x}=\[k_{C4AF}\left(Fe2O3\right)\left(CaO\right)\left(C3A\right)M_{C4AF}\]/u_s;$

$\frac{\∂C3S}{\∂x}=\[k_{C3S}\left(CaO\right)\left(C2S\right)M_{C3S}\]/u_s;$

Wherein, Ca2O3, SiO2, Al2O3, Fe2O3, CaO are respectively Calcium Carbonate in raw material, silicon oxide, aluminium oxide, ferrum oxide, oxygen Change the mass fraction of calcium, %；C2S, C3A, C4AF, C3S are respectively dicalcium silicate in grog, tricalcium aluminate, tetra calcium aluminoferrite, silicon The mass fraction of sour DFP, %；M_CaCO3、M_SiO2、M_Al2O3、M_Fe2O3、M_CaO、M_C2S、M_C3A、M_C4AF、M_C3SIt is respectively Calcium Carbonate, oxidation Silicon, aluminium oxide, ferrum oxide, calcium oxide, dicalcium silicate, tricalcium aluminate, tetra calcium aluminoferrite, the molal weight of tricalcium silicate, g/ mol；k_CaCO3、k_C2S、k_C3A、k_C4AF、k_C3SIt is respectively that Calcium Carbonate, dicalcium silicate, tricalcium aluminate, tetra calcium aluminoferrite, tricalcium silicate enter The speed of row reaction, 1/s.

6. the one-dimensional emulation mode of cement rotary kiln clinker burning quality is predicted as claimed in claim 1, it is characterised in that：

According to mineral reaction process, reaction liberated heat is as follows：

$Q_c=m_s\[-{\mathrm{\ΔH}}_{CaCO3}\frac{dCaCO3}{dx}-{\mathrm{\ΔH}}_{C2S}\frac{dC2S}{dx}-{\mathrm{\ΔH}}_{C3A}\frac{dC3A}{dx}-{\mathrm{\ΔH}}_{C4AF}\frac{dC4AF}{dx}-{\mathrm{\ΔH}}_{C3S}\frac{dC3S}{dx}\]$

Wherein, Δ H_CaCO3、ΔH_C2S、ΔH_C3A、ΔH_C4AF、ΔH_C3SRespectively Calcium Carbonate, dicalcium silicate, tricalcium aluminate, ferrum aluminic acid The reaction heat that four calcium, tricalcium silicate are reacted, J/kg.

7. the one-dimensional emulation mode of cement rotary kiln clinker burning quality is predicted as claimed in claim 6, it is characterised in that：

The reaction rate expression formula of each reaction is as follows：

k_j=A_jexp(-E_j/RT_s)；

Wherein, A_jTo react j pre-exponential factors, s-1；E_jTo react the activation energy of j, J/ (molK)；J then represents Calcium Carbonate, silicon Sour dicalcium, tricalcium aluminate, tetra calcium aluminoferrite, five reactions of tricalcium silicate.