CN101598688A - Boiler Ash fouling monitoring and soot blowing and optimal method based on the ature of coal on-line measurement - Google Patents

Abstract

The invention discloses Boiler Ash fouling monitoring and soot blowing and optimal method based on the ature of coal on-line measurement, at the shortcoming and defect of existing soot blowing and optimal method based on the measurement of coal analysis off-line data, based on boiler integral body and local energy and mass balance principle, adopt the on-line analysis of ature of coal in-line analyzer to go into the stove ature of coal, contrary flue gas flow is to the dust stratification slagging scorification of each main convection heating surface, the boiler furnace outlet flue-gas temperature is carried out on-line monitoring and analytical calculation, calculate and analyze the running status and the contaminated degree of the heating surface of boiler in real time, eliminate pulverized coal firing boiler and gone into the harmful effect that the variation of stove ature of coal is instructed soot blowing and optimal, ash instructs and boiler performance is optimized data for the pulverized coal power boiler operation provides correct blowing, thereby reduced boiler coal consumption, finally improved the security and the economy of boiler operatiopn.

Description

Boiler Ash fouling monitoring and soot blowing and optimal method based on the ature of coal on-line measurement

Technical field

The present invention is a kind of at pulverized coal power boiler convection heating surface ash fouling monitoring and soot blowing and optimal method, particularly a kind of based on boiler integral body and local energy and mass balance principle, go into the stove ature of coal by online detection, contrary flue gas flow carries out on-line monitoring and analytical calculation to dust stratification slagging scorification, the boiler furnace outlet flue-gas temperature of each main convection heating surface, calculate and analyze the running status and the pollution level of the heating surface of boiler in real time, realize the quantification and the visual power-economizing method of heating surface pollution level, belong to thermal power engineering and energy saving optimizing field.

Background technology

Domestic station boiler is based on fire coal, and the steam coal quality is bad partially, and dust burdening and sulfur content etc. are all higher, form contamination, dust stratification, corrosion and the wearing and tearing of heating surface easily.The dust stratification slagging scorification of boiler heating surface increases heat transfer resistance, actual measurement in the boiler operatiopn shows, when burner hearth dust stratification thickness increases to 2 millimeters by 1 millimeter, heat transfer efficiency reduces 28%, for satisfying the requirement of load, to increase fuel quantity with the increase heat absorption toward contact, thereby increase the coal consumption of unit, cause economy to descend.Boiler heating surface dust stratification and slagging scorification also can promote the corrosion of heating surface, reduce heating surface serviceable life, when serious even lead to major accident such as booster shutdown.

Slight slagging scorification and dust stratification such as untimely processing then may continue development, worsen.No matter slagging scorification and dust stratification are at burner hearth or convection heating surface, all will produce adverse influence to boiler, are effective solution and blow ash.Soot blower is to utilize certain grey medium (water, steam, sound wave, combustion gas etc.) cleaning heating surface that blows, and removes the dirt on heating surface surface, makes its surface recovery clean conditions.

Yet, aspect the formulation of blowing grey scheme, mostly power plant is the requirement in the design instruction that is provided according to the boiler manufacturer or works out according to the operating experience of other power plant's similar devices that put into operation, and in fact these ways may have blindness, and human factor has played sizable effect.This might cause, and the serious heating surface of dust stratification can not get timely purging in the boiler, also might cause the slight heating surface of dust stratification frequently to purge, and causes the boiler booster easily.Therefore, press on the basis of the real-time Monitoring Data of unit, the operation instruction that the ash operation provides direct-on-line that blows for unit carries out reliable on-line analysis to the security and the economy of unit operation, improves the safety and economy of unit.

Abroad early to the starting of boiler soot-blowing Study on optimized, the Soot-blower Advisor expert system that New York electric power gas company and general physics company develop jointly, crucial parameter measurement value in use boiler and the steam turbine circulation is determined the cleaning factor of boiler different parts, helps the operations staff to determine to blow the ash strategy.The SR4 of Germany is the unit efficiency analysis optimization module among the Sienergy of operation optimum management system, heating surface to zones of different in the boiler carries out heat transfer efficiency calculating, change according to parameters such as spray water flux, exhaust gas temperatures, by calculating to instruct soot blower to carry out the zonal ash that irregularly blows.The Optimax of Switzerland ABB AB is online power plant efficiency software for calculation bag, and its boiler cleaning module can be in the cleanliness of line computation heat-transfer surface and the smoke inlet temperature of each heat-transfer surface, and the result is used to optimize the working procedure of boiler sootblower.The Smart ProcessTM of Westinghouse Electric uses the neural network instrument to determine to blow grey frequency and position, to realize the loss of the minimum thermal efficiency and process, and the life-span of prolongation unit equipment, utilize neural network to calculate the actual heat transfer capacity in each soot blower zone of boiler, information is obtained cleanliness factor and is made comparisons with ideal value in view of the above, grey guiding opinion is blown in formation, and the result of optimization can incorporate existing DCS into and form closed-loop control, also can supply operations staff's reference.But the introduction expense of these systems is higher, implements also comparatively difficulty on the unit at home simultaneously.

Domestic also have some R﹠D institutions and enterprise to develop the soot blowing and optimal system, but existing soot blowing and optimal system is based on the measurement of coal analysis off-line data mostly, and China's power plant soot ature of coal is changeable, often big off-design value, existing soot blowing and optimal system often can not change real-time update system coal analysis data according to going into the stove ature of coal, cause system-computed data and boiler unit actual conditions to have, had a strong impact on and blown the correctness that ash instructs than large deviation.Simultaneously, constantly perfect along with fuel-burning power plant computer control and data management system requires the soot blowing and optimal system to carry out remote access by webpage, becomes the part of plant level supervisory information system (SIS system).

Therefore develop the Boiler Ash fouling monitoring and the soot blowing and optimal system of a cover based on the ature of coal on-line measurement, and storage, long-range demonstration and the inquiry of realization system data, production efficiency and the economic benefit that improves enterprise there is significance, is fit to the needs of enterprise's future development.

Summary of the invention

Technical matters: at the shortcoming and defect of existing soot blowing and optimal method, in order to realize the grey fouling monitoring and the soot blowing and optimal of pulverized coal power boiler convection heating surface, the present invention proposes a kind of Boiler Ash fouling monitoring and soot blowing and optimal method based on the ature of coal on-line measurement, eliminated pulverized coal firing boiler and gone into the harmful effect of stove ature of coal variation the soot blowing and optimal system, ash instructs and boiler performance is optimized data for the pulverized coal power boiler operation provides correct blowing, thereby reduced boiler coal consumption, finally improved the economy of boiler.

Technical scheme: Boiler Ash fouling monitoring and soot blowing and optimal method based on the ature of coal on-line measurement of the present invention are to realize by following technical scheme:

This method comprises as lower module: measuring point data acquisition module, computing module, real-time historical data transit module, data disaply moudle; The required measuring point of this method and original measuring point data that computing module is gathered according to the measuring point module, contrary flue gas flow carries out heating power to each convection heating surface and calculates, obtain the grey dirty factor and the dirty factor of critical ash of each convection heating surface, provide and blow the ash guidance, and send result of calculation to real-time historical data transit module, the historical data transit module shows by data disaply moudle real-time result of calculation on picture in real time, and historical data is sent in the database; The measuring point data acquisition module by the newly-increased primary instrument of boiler, coal analysis instrument and newly-increased DAS system, is gathered measuring point data, and these data is sent into the real-time history data store device of boiler.

The measuring point data acquisition module adopts the real-time analysis of ature of coal in-line analyzer to go into the elementary composition and the calorific value of stove fire coal, and analysis result is sent into the real-time history data store device of boiler.

Computing module comprises the steps:

Step 1: the structural parameters such as tube side, caliber, flue gas circulation area and heat exchange area that boiler body, convection recuperator are set;

Step 2: the interface function that provides by the real-time history data store device of boiler manufacturer, from boiler data storage device acquisition system desired data;

Step 3: the data of being gathered from the boiler data storage device are carried out data check, have only when all measuring point datas all at limited range, just enter the computing module master routine and calculate, otherwise, withdraw from computing module and send the data alerting signal of makeing mistakes to picture;

Step 4: calculate the flue gas physical property, the data that provide according to coal analysis instrument, when calculating 1 kilogram of fired coal combustion:

I) theoretical air volume, its formula is:

V ⁰＝0.0889(C ^ar+0.375S ^ar)+0.265H ^ar-0.0333O ^ar；

J) theoretical water steam volume, its formula is:

$V_{H_{2}O}^0=0.0124W^{\mathrm{ar}}+0.111H^{\mathrm{ar}}+0.0161V^0;$

K) theoretical nitrogen volume, its formula is: $V_{N_2}^0=0.8\frac{N^{\mathrm{ar}}}{100}+0.79V^0;$

L) theoretical three atomic gas volumes, its formula is: $V_{{\mathrm{RO}}_2}^0=1.866\frac{C^{\mathrm{ar}}}{100}+0.7\frac{S^{\mathrm{ar}}}{100};$

M) actual water vapor volume, its formula is: $V_{H_{2}O}=V_{H_{2}O}^0+0.0161(\mathrm{\α}-1)V^0;$

N) actual flue gas volume, its formula is: $V_y=V_{{\mathrm{RO}}_2}^0+V_{N_2}^0+V_{H_{2}O}+(\mathrm{\α}-1)V^0;$

O) air enthalpy can calculate by function C oldAirEnth, the ColdAirEnth function with gas or the ash temperature be the function input parameter, with gas or the ash enthalpy be the function output parameter, match 0 to 2000 ℃ air and O ₂, CO ₂, H ₂O, N ₂Deng the mean specific heat of gas and the enthalpy of 1 kilogram of ash;

P) flue gas enthalpy can be according to O ₂, CO ₂, H ₂O, N ₂Volume composition and flue-gas temperature Deng gas utilize function C oldAirEnth to calculate;

Wherein, C ^Ar, H ^Ar, O ^Ar, N ^Ar, S ^ArBe the as received basis composition of coal-fired ultimate analysis, %; W ^ArBe coal-fired ultimate analysis as received basis moisture content, %; α is an excess air coefficient, can pass through formula $\mathrm{\α}=\frac{21}{21-O_2}$ Obtain O in the formula ₂Be oxygen level in the flue gas; V ⁰Be theoretical air volume, Nm ³/ kg;

Be theoretical water steam volume, Nm ³/ kg;

Be theoretical nitrogen volume, Nm ³/ kg;

Be theoretical three atomic gas volumes, Nm ³/ kg;

Be actual water vapor volume, Nm ³/ kg; V _yBe actual flue gas volume, Nm ³/ kg;

Step 5: calculate boiler coal consumption, with the thermal efficiency and the coal-fired consumption of counter balancing method calculating boiler unit,

I) heat loss due to combustibles in refuse $q_{}$ ${}_4=\frac{7850A^{\mathrm{ar}}}{Q_r}(\frac{{\mathrm{\α}}_{\mathrm{fh}}{C}_{\mathrm{fh}}}{100-C_{\mathrm{fh}}}+\frac{{\mathrm{\α}}_{\mathrm{lz}}{C}_{\mathrm{lz}}}{100-C_{\mathrm{lz}}});$

J) heat loss due to unburned gas is for coal-powder boiler, optional q ₃=0;

K) heat loss due to exhaust gas $q_2=\frac{I_{\mathrm{py}}-{\mathrm{\α}}_{\mathrm{py}}{I}_{\mathrm{lk}}^0}{Q_r}\×(100-q_4);$

L) radiation loss $q_5=q_5^e\frac{D_e}{D};$

M) heat loss due to sensible heat in slag $q_6=\frac{A^{\mathrm{ar}}{\mathrm{\α}}_{\mathrm{lz}}{\left(\mathrm{c\θ}\right)}_{\mathrm{lz}}}{Q_r};$

N) boiler efficiency η=1-q ₂-q ₃-q ₄-q ₅-q ₆

O) the total heat of effectively utilizing of boiler

Q＝D _gq(i″ _gq-i _gs)+D _zq(i″ _zq-i′ _zq)+D _bq(i _bq-i _gs)+D _pw(i _pw-i _gs)；

P) calculate coal-fired consumption $B_j=\frac{Q}{\mathrm{\η}{Q}_r};$

A wherein ^ArBe coal-fired ultimate analysis as received basis ash, %; Q _rBe that 1 kilogram of fire coal is gone into stove heat, kJ/kg; C _Fh, C _LzBe the content percentage of carbon residue in flying dust and the slag, %; α _FhBe the grey share that accounts for fuel ash in the flying dust, %; α _LzFor the ash in the slag accounts for the share of ash content in the fuel, %; I _PyBe smoke evacuation enthalpy, kJ/kg; I _Lk ⁰Be theoretical cold air enthalpy, kJ/kg; α _PyBe the excess air coefficient behind the air preheater; q ₅ ^eBe radiation loss under the boiler rating, %; D _eBe rated capacity, kg/h; D is the boiler actual evaporation, kg/h; (c θ) _LzBe the product of slag specific heat and its temperature, i.e. the enthalpy of 1 kilogram of ash when temperature θ, kJ/kg; D _GqBe superheat steam flow, kg/h; D _ZqBe reheated steam flow, kg/h; D _BqUse saturated vapour flow, kg/h for taking out; D _PwBe water amount of blowdown, kg/h; I " _GqBe superheated vapor outlet enthalpy, kJ/kg; I " _Zq, i ' _ZqBe reheated steam outlet and inlet enthalpy, kJ/kg; i _BqBe the enthalpy of saturated vapour, kJ/kg; i _PwBe sewer enthalpy, kJ/kg; i _GsBe boiler feed water enthalpy, kJ/kg;

Step 6: calculate the dirty factor of air preheater ash, import and export the index η that flue gas pressure reduction calculates the dirty degree of air preheater heating surface ash according to the air preheater heating surface _Sj:

c) ${\mathrm{\η}}_{\mathrm{sj}}=\frac{2\mathrm{\ΔP}}{{\left(\mathrm{wF}\right)}^2\mathrm{\ρ}}=\frac{273\mathrm{\ΔP}\·2g}{{\left(3600B_j\right)}^2{V}_y{G}_y(T+273)}=C\frac{\mathrm{\ΔP}}{B_j^2{V}_y{G}_y(T+273)};$

D) the grey dirty factor FF of calculating air preheater _Ky:

${\mathrm{FF}}_{\mathrm{ky}}=\frac{{\mathrm{\η}}_{\mathrm{lx}}-{\mathrm{\η}}_{\mathrm{sj}}}{{\mathrm{\η}}_{\mathrm{lx}}}$

Wherein, Δ P is the pressure drop of this section heating surface, N/m ²B _jFor calculating Coal-fired capacity, kg/h; G _yBe 1 kilogram of coal combustion gained flue gas quality, its formula is: G _y=1-A ^Ar/ 100+1.036 α V ⁰, kg/kg; V _yBe 1 kilogram of coal combustion gained flue gas volume, m ³/ kg; ρ is a smoke density, kg/m ³W is a flue gas flow rate, m/s; F is the flue sectional area, m ²C is a constant coefficient; η _SjBe the actual computation value; η _LxBe numerical value ideally; FF _KyThe grey dirty factor for air preheater;

Step 7: calculate the dirty factor FF of convection heating surface ash _Dl,

d) ${\mathrm{FF}}_{\mathrm{dl}}=\frac{K_{\mathrm{lx}}-K_{\mathrm{sj}}}{K_{\mathrm{lx}}};$

e)Q _sj＝D(i″-i′+Δi _jw)/B _j；

f) $K_{\mathrm{sj}}=\frac{Q_{\mathrm{sj}}}{A\·\mathrm{\Δt}};$

More than various in: i ', i " be the steam enthalpy of heating surface import and outlet, kJ/kg; Δ i _JwBe desuperheating water enthalpy, kJ/kg; A is the heating surface heat transfer area, m ², Δ t is a heat transfer temperature difference, K; FF _DlIt is the dirty factor of convection heating surface ash; K _LxBe the desirable heat transfer coefficient of air preheater, kJ/ (m ²K); K _SjThe actual heat transfer coefficient of air preheater heating surface, kJ/ (m ²K);

Step 8: calculate the dirty factor of furnace wall cooling ash

D) calculate furnace outlet gas temperature

E) burner hearth evenly heat coefficient of efficiency

-3-

F) the dirty factor of furnace wall cooling ash

${\mathrm{\ζ}}_{\mathrm{pj}}=\frac{{\mathrm{\ψ}}_{\mathrm{pj}}}{x_{\mathrm{pj}}};$

Wherein, T _aBe theoretical temperature combustion, K; M represents the constant of flame central position for considering the coefficient of flame central position; σ ₀Be Boltzmann constant, 5.67 * 10 ^-8, W/ (m ²K ⁴); a _lThe burner hearth blackness is the imaginary blackness of the effective radiation of an expression flame; F _LtThe burner hearth area, m ² Protect hot coefficient; B _jComputing fuel level, kg/h; VC _PjFlue gas arrives θ at 0 ℃ " _LtBetween mean heat capacity, kJ/ (kg ℃); x _PjBe the angle factor of water screen tube, relevant with the structural arrangement of water-cooling wall;

Step 9: calculate the dirty factor of critical ash, the calculating energy net proceeds

$Q_{\mathrm{net}}=Q_{\mathrm{in}}-Q_{\mathrm{out}}=Q_{f\_n}-Q_{f\_0}-Q_{\mathrm{out}}$

$=F(n{\∫}_{{\mathrm{\τ}}_0}^{{\mathrm{\τ}}_0+\mathrm{\Δ\τ}/n}(1-f\left(\mathrm{\τ}\right))K_{\mathrm{lx}}\mathrm{\ΔTd\τ}-{\∫}_{{\mathrm{\τ}}_0}^{{\mathrm{\τ}}_0+\mathrm{\Δ\τ}}(1-f\left(\mathrm{\τ}\right))K_{\mathrm{lx}}\mathrm{\ΔTd\τ})-n*{\mathrm{\τ}}_1*m*(I_{\mathrm{chou}}-I_0)$

Ask max (Q _Net), optimum frequency that can this top blast ash that is heated, substitution formula FF=f (τ) tries to achieve the dirty factor of the critical ash of each heating surface under the current working; Q wherein _{F_0}Be the heat during the soot blower attonity in this period, kJ; Q _{F_n}Heat when having carried out blowing ash n time for this period, kJ; Q _OutFor blowing the heat of grey steam consumption, kJ for n time; F is the heating surface heat transfer area, m ²Δ T is a logarithm mean temperature difference; F (τ) changes function for the grey dirty factor with blowing the grey frequency (time); I _ChouBe the vapour source enthalpy of the used steam of soot blower, kJ/kg; I ₀Be condenser inlet enthalpy, kJ/kg;

Step 10: boiler heating power result of calculation and boiler soot-blowing instruction are sent to real-time historical data transfer platform;

Described real-time historical data transit module deposits real-time result of calculation in calculator memory, treats next result of calculation arrival constantly, and previous moment data form computer internal memory is moved into database, the real time data in the update calculation machine internal memory then.

Described data disaply moudle shows the real-time result of calculation of the dirty factor of each convection heating surface ash in real time on the icon top of correspondence, and with the state of the dust stratification of yellow, pink and red three kinds of each section of color showing convection heating surfaces:, represent with yellow icon when the dirty factor of heating surface ash is slight pollution during less than 70% the dirty factor of critical ash; When the dirty factor of heating surface ash is intermediate pollution greater than 70% the dirty factor of critical ash during less than the dirty factor of critical ash, represent with pink icon; When the dirty factor of heating surface ash is serious pollution during greater than the dirty factor of critical ash, represent with red icon, point out this top blast ash group of being heated to blow ash simultaneously.

Beneficial effect: the present invention compares with existing soot blowing and optimal system, adopted the ature of coal in-line analyzer, can carry out heating power calculating to boiler according to going into stove ature of coal real-time change, obtain the grey dirty factor of each convection heating surface, thereby can react the contaminated situation of each convection heating surface of boiler more accurately.Simultaneously, the present invention is also visual with the heating surface pollution level, show the dirty factor of boiler heating surface ash in real time by the picture configuration, provide and blow the gray signal prompting, and provide historical trend to inquire about and remote access function, provide and better blow ash and instruct for blowing grey operations staff, improved the security and the economy of boiler of power plant operation.

Description of drawings

Fig. 1 soot blowing and optimal grid synoptic diagram,

Fig. 2 soot blowing and optimal algorithm flow chart,

Fig. 3 boiler increases the measuring point synoptic diagram newly.

Embodiment

Boiler Ash fouling monitoring and soot blowing and optimal method based on the ature of coal on-line measurement, comprise boiler DCS (Distributed Control System) the original primary instrument of components of system as directed, the data storage device that is used to deposit the real-time historical data of boiler, the newly-increased primary instrument of boiler, newly-increased DAS (Data Acquisition System) system, coal analysis instrument, industrial computer and server, boiler increases primary instrument newly, newly-increased DAS system links to each other successively with industrial computer.Industrial computer is as newly-increased measuring point data acquisition system, by the newly-increased primary instrument of boiler, coal analysis instrument and newly-increased DAS system, gathers newly-increased measuring point data, and data are sent into the boiler data storage device.Server is as the computing module of total system, memory module and result show the platform of enquiry module as a result, gather required measuring point data by interface routine from the boiler data storage device, boiler is carried out heating power calculate, and by real-time historical data transfer platform storage, demonstration and inquiry result of calculation.The newly-increased primary instrument of boiler comprises: be used to measure each convection heating surface heat exchanger inlet and outlet flue-gas temperature pyrometer couple, be used to measure each convection heating surface heat interchanger working medium out temperature low temperature thermocouple, be used to measure the pressure transducer and the differential pressure pick-up of air preheater inlet and outlet pressure and differential pressure.Computing module is according to the on-line measurement data of coal analysis instrument, the ultimate analysis and the calorific value of real-time update computing module ature of coal.

Boiler Ash fouling monitoring and soot blowing and optimal method based on the ature of coal on-line measurement of the present invention comprises as lower module: measuring point data acquisition module, computing module, real-time historical data transit module, data disaply moudle; The required measuring point of this method and original measuring point data that computing module is gathered according to the measuring point module, contrary flue gas flow carries out heating power to each convection heating surface and calculates, obtain the grey dirty factor and the dirty factor of critical ash of each convection heating surface, provide and blow the ash guidance, and send result of calculation to real-time historical data transit module, the historical data transit module shows by data disaply moudle real-time result of calculation on picture in real time, and historical data is sent in the database.

The measuring point data acquisition module by the newly-increased primary instrument of boiler, coal analysis instrument and newly-increased DAS system, is gathered measuring point data, and these data is sent into the real-time history data store device of boiler.The measuring point data acquisition module adopts the real-time analysis of ature of coal in-line analyzer to go into the elementary composition and the calorific value of stove fire coal, and analysis result is sent into the real-time history data store device of boiler.

Its computing module comprises the steps:

Step 1: the structural parameters such as tube side, caliber, flue gas circulation area and heat exchange area that boiler body, convection recuperator are set;

Step 2: the interface function that provides by boiler data storage device manufacturer, from boiler data storage device acquisition system desired data;

Step 3: the data of being gathered from the boiler data storage device are carried out data check, have only when all measuring point datas all at limited range, just enter the computing module master routine and calculate, otherwise, withdraw from computing module and send the data alerting signal of makeing mistakes to picture;

Step 4: calculate the flue gas physical property, the data that provide according to coal analysis instrument, when calculating 1 kilogram of fired coal combustion

Q) theoretical air volume, its formula is:

V ⁰＝0.0889(C ^ar+0.375S ^ar)+0.265H ^ar-0.0333O ^ar；

R) theoretical water steam volume, its formula is:

$V_{H_{2}O}^0=0.0124W^{\mathrm{ar}}+0.111H^{\mathrm{ar}}+0.0161V^0;$

S) theoretical nitrogen volume, its formula is: $V_{N_2}^0=0.8\frac{N^{\mathrm{ar}}}{100}+0.79V^0;$

T) theoretical three atomic gas volumes, its formula is: $V_{{\mathrm{RO}}_2}^0=1.866\frac{C^{\mathrm{ar}}}{100}+0.7\frac{S^{\mathrm{ar}}}{100};$

U) actual water vapor volume, its formula is: $V_{H_{2}O}=V_{H_{2}O}^0+0.0161(\mathrm{\α}-1)V^0;$

V) actual flue gas volume, its formula is: $V_y=V_{{\mathrm{RO}}_2}^0+V_{N_2}^0+V_{H_{2}O}+(\mathrm{\α}-1)V^0;$

W) air enthalpy can calculate by function C oldAirEnth, the ColdAirEnth function with gas or the ash temperature be the function input parameter, with gas or the ash enthalpy be the function output parameter, match 0 to 2000 ℃ air and O ₂, CO ₂, H ₂O, N ₂Deng the mean specific heat of gas and the enthalpy of 1 kilogram of ash;

X) flue gas enthalpy can be according to O ₂, CO ₂, H ₂O, N ₂Volume composition and flue-gas temperature Deng gas utilize function C oldAirEnth to calculate;

Wherein, C ^Ar, H ^Ar, O ^Ar, N ^Ar, S ^ArBe the as received basis composition of coal-fired ultimate analysis, %; W ^ArBe coal-fired ultimate analysis as received basis ash, %; α is an excess air coefficient, can pass through formula $\mathrm{\α}=\frac{21}{21-O_2}$ Obtain O in the formula ₂Be oxygen level in the flue gas; V ⁰Be theoretical air volume, Nm ³/ kg;

Be theoretical water steam volume, Nm ³/ kg; Be theoretical nitrogen volume, Nm ³/ kg; Be theoretical three atomic gas volumes, Nm ³/ kg;

Be actual water vapor volume, Nm ³/ kg; V _yBe actual flue gas volume, Nm ³/ kg;

Step 5: calculate boiler coal consumption, with the thermal efficiency and the coal-fired consumption of counter balancing method calculating boiler unit,

A) heat loss due to combustibles in refuse $q_{}$ ${}_4=\frac{7850A^{\mathrm{ar}}}{Q_r}(\frac{{\mathrm{\α}}_{\mathrm{fh}}{C}_{\mathrm{fh}}}{100-C_{\mathrm{fh}}}+\frac{{\mathrm{\α}}_{\mathrm{lz}}{C}_{\mathrm{lz}}}{100-C_{\mathrm{lz}}});$

B) heat loss due to unburned gas is for coal-powder boiler, optional q ₃=0;

C) heat loss due to exhaust gas $q_2=\frac{I_{\mathrm{py}}-{\mathrm{\α}}_{\mathrm{py}}{I}_{\mathrm{lk}}^0}{Q_r}\×(100-q_4);$

D) radiation loss $q_5=q_5^e\frac{D_e}{D};$

E) heat loss due to sensible heat in slag $q_6=\frac{A^{\mathrm{ar}}{\mathrm{\α}}_{\mathrm{lz}}{\left(\mathrm{c\θ}\right)}_{\mathrm{lz}}}{Q_r};$

F) boiler efficiency η=1-q ₂-q ₃-q ₄-q ₅-q ₆

G) the total heat of effectively utilizing of boiler

Q＝D _gq(i″ _gq-i _gs)+D _zq(i″ _zq-i′ _zq)+D _bq(i _bq-i _gs)+D _pw(i _pw-i _gs)；

H) calculate coal-fired consumption $B_j=\frac{Q}{\mathrm{\η}{Q}_r};$

A wherein ^ArBe coal-fired ultimate analysis as received basis ash, %; Q _rBe that 1 kilogram of fire coal is gone into stove heat, kJ/kg; C _Fh, C _LzBe the content percentage of carbon residue in flying dust and the slag, %; α _FhBe the grey share that accounts for fuel ash in the flying dust, %; α _LzFor the ash in the slag accounts for the share of ash content in the fuel, %; I _PyBe smoke evacuation enthalpy, kJ/kg; I _Lk ⁰Be theoretical cold air enthalpy, kJ/kg; α _PyBe the excess air coefficient behind the air preheater; q ₅ ^eBe radiation loss under the boiler rating, %; D _eBe rated capacity, kg/h; D is the boiler actual evaporation, kg/h; (c θ) _LzBe the product of slag specific heat and its temperature, i.e. the enthalpy of 1 kilogram of ash when temperature θ, kJ/kg; D _GqBe superheat steam flow, kg/h; D _ZqBe reheated steam flow, kg/h; D _BqUse saturated vapour flow, kg/h for taking out; D _PwBe water amount of blowdown, kg/h; I " _GqBe superheated vapor outlet enthalpy, kJ/kg; I " _Zq, i ' _ZqBe reheated steam outlet and inlet enthalpy, kJ/kg; i _BqBe the enthalpy of saturated vapour, kJ/kg; i _PwBe sewer enthalpy, kJ/kg; i _GsBe boiler feed water enthalpy, kJ/kg;

Step 6: calculate the dirty factor of air preheater ash, import and export flue gas pressure reduction according to the air preheater heating surface and calculate air preheater

The index η of the dirty degree of heating surface ash _Sj:

a) ${\mathrm{\η}}_{\mathrm{sj}}=\frac{2\mathrm{\ΔP}}{{\left(\mathrm{wF}\right)}^2\mathrm{\ρ}}=\frac{273\mathrm{\ΔP}\·2g}{{\left(3600B_j\right)}^2{V}_y{G}_y(T+273)}=C\frac{\mathrm{\ΔP}}{B_j^2{V}_y{G}_y(T+273)};$

B) the grey dirty factor FF of calculating air preheater _Ky:

${\mathrm{FF}}_{\mathrm{ky}}=\frac{{\mathrm{\η}}_{\mathrm{lx}}-{\mathrm{\η}}_{\mathrm{sj}}}{{\mathrm{\η}}_{\mathrm{lx}}}$

Wherein, Δ P is the pressure drop of this section heating surface, N/m ²B _jFor calculating Coal-fired capacity, kg/h; G _yBe 1 kilogram of coal combustion gained flue gas quality, its formula is: G _y=1-A ^Ar/ 100+1.036 α V ⁰, kg/kg; V _yBe 1 kilogram of coal combustion gained flue gas volume, m ³/ kg; ρ is a smoke density, kg/m ³W is a flue gas flow rate, m/s; F is the flue sectional area, m ²C is a constant coefficient; η _SjBe the actual computation value; η _LxBe numerical value ideally; FF _KyThe grey dirty factor for air preheater;

Step 7: calculate the dirty factor FF of convection heating surface ash _Dl,

a) ${\mathrm{FF}}_{\mathrm{dl}}=\frac{K_{\mathrm{lx}}-K_{\mathrm{sj}}}{K_{\mathrm{lx}}};$

b)Q _sj＝D(i″-i′+Δi _jw)/B _j；

c) $K_{\mathrm{sj}}=\frac{Q_{\mathrm{sj}}}{A\·\mathrm{\Δt}};$

More than various in: i ', i " be the steam enthalpy of heating surface import and outlet, kJ/kg; Δ i _JwBe desuperheating water enthalpy, kJ/kg; A is the heating surface heat transfer area, m ², Δ t is a heat transfer temperature difference, K; FF _DlIt is the dirty factor of convection heating surface ash; K _LxBe the desirable heat transfer coefficient of air preheater, kJ/ (m ²K); K _SjThe actual heat transfer coefficient of air preheater heating surface, kJ/ (m ²K);

Step 8: calculate the dirty factor of furnace wall cooling ash

A) calculate furnace outlet gas temperature

B) burner hearth evenly heat coefficient of efficiency

C) the dirty factor of furnace wall cooling ash

${\mathrm{\ζ}}_{\mathrm{pj}}=\frac{{\mathrm{\ψ}}_{\mathrm{pj}}}{x_{\mathrm{pj}}};$

Wherein, T _aBe theoretical temperature combustion, K; M represents the constant of flame central position for considering the coefficient of flame central position; σ ₀Be Boltzmann constant, 5.67 * 10 ^-8, W/ (m ²K ⁴); a _lThe burner hearth blackness is the imaginary blackness of the effective radiation of an expression flame; F _LtThe burner hearth area, m ²

Protect hot coefficient; B _jComputing fuel level, kg/h; VC _PjFlue gas arrives θ at 0 ℃ " _LtBetween mean heat capacity, kJ/ (kg ℃); x _PjBe the angle factor of water screen tube, relevant with the structural arrangement of water-cooling wall;

Step 9: calculate the dirty factor of critical ash, the calculating energy net proceeds

$Q_{\mathrm{net}}=Q_{\mathrm{in}}-Q_{\mathrm{out}}=Q_{f\_n}-Q_{f\_0}-Q_{\mathrm{out}}$

$=F(n{\∫}_{{\mathrm{\τ}}_0}^{{\mathrm{\τ}}_0+\mathrm{\Δ\τ}/n}(1-f\left(\mathrm{\τ}\right))K_{\mathrm{lx}}\mathrm{\ΔTd\τ}-{\∫}_{{\mathrm{\τ}}_0}^{{\mathrm{\τ}}_0+\mathrm{\Δ\τ}}(1-f\left(\mathrm{\τ}\right))K_{\mathrm{lx}}\mathrm{\ΔTd\τ})-n*{\mathrm{\τ}}_1*m*(I_{\mathrm{chou}}-I_0)$

Ask max (Q _Net), optimum frequency that can this top blast ash that is heated, substitution formula FF=f (τ) tries to achieve the dirty factor of the critical ash of each heating surface under the current working; Q wherein _{F_0}Be the heat during the soot blower attonity in this period, kJ; Q _{F_n}Heat when having carried out blowing ash n time for this period, kJ; Q _OutFor blowing the heat of grey steam consumption, kJ for n time; F is the heating surface heat transfer area, m ²Δ T is a logarithm mean temperature difference; F (τ) changes function for the grey dirty factor with blowing the grey frequency (time); I _ChouBe the vapour source enthalpy of the used steam of soot blower, kJ/kg; I ₀Be condenser inlet enthalpy, kJ/kg;

Step 10: data transmitting module sends to real-time historical data transfer platform with boiler heating power result of calculation and boiler soot-blowing instruction;

The historical data transit module deposits real-time result of calculation in calculator memory in real time, treats next result of calculation arrival constantly, and previous moment data form computer internal memory is moved into database, the real time data in the update calculation machine internal memory then.Data disaply moudle, the real-time result of calculation of the dirty factor of each convection heating surface ash is shown in real time on the icon top of correspondence, and with the state of the dust stratification of yellow, pink and red three kinds of each section of color showing convection heating surfaces:, represent with yellow icon when the dirty factor of heating surface ash is slight pollution during less than 70% the dirty factor of critical ash; When the dirty factor of heating surface ash is intermediate pollution greater than 70% the dirty factor of critical ash during less than the dirty factor of critical ash, represent with pink icon; When the dirty factor of heating surface ash is serious pollution during greater than the dirty factor of critical ash, represent with red icon, point out this top blast ash group of being heated to blow ash simultaneously.

After finishing the collection of data, verification and calculating, result of calculation is by the real-time historical data transfer platform based on SQL database of independent development in real time, being sent to the webpage configuration picture shows in real time, historical data is sent into SQL database, and the demonstration of webpage real time data, historical trend inquiry and the remote access module developed based on the .NET platform have realized that result of calculation shows in real time, historical trend is inquired about and remote access function.

Be applied as example with the present invention at certain power plant's 600MW subcritical boiler, concrete implementation step is as follows:

Step 1. hardware is installed:

Analyze needs for satisfying aforementioned calculation,,, form a cover DAS system, the data acquisition of finishing newly-increased measuring point and transforming measuring point by front end processor by increasing and transform some temperature and pressure measuring points newly according to the existing measuring point situation of this factory.The data of gathering insert unit DCS system by the address card of front end processor, data are sent into the PI system by the interface message processor (IMP) of DCS and PI system, the soot blowing and optimal system server is obtained data necessary by the PI system, through Model Calculation, the result is turned back on the OPM display terminal of pulpit, for operations staff's reference, instruct and blow grey process, system network architecture is as shown in Figure 1.

According to the existing measuring point of #1 unit boiler, for satisfying the real-time monitoring calculation needs of relevant heating surface heat exchange, set up 22 measuring points, newly-increased 22 measuring points comprise: 4 measuring points of low temperature superheater inlet steam temperature, 2 measuring points of low temperature superheater inlet cigarette stripping temperature, 2 measuring points of high temperature superheater entrance flue gas temperature, 4 measuring points of economizer exit feed temperature, 2 measuring points of economizer entrance flue gas temperature, 4 measuring points of wall type reheater outlet steam temperature, 4 measuring points of division pendant superheater outlet steam temperature, newly-increased measuring point distributes as shown in Figure 3.

Step 2. computing module is developed with VC++6.0MFC, and concrete steps are as follows:

1. boiler structure parameter initialization

According to the Structure Calculation book and the heating power calculated description of boiler, the structural parameters such as tube side, caliber, flue gas circulation area and heat exchange area of boiler body, convection recuperator are set.

2. data acquisition and verification

The ODBC linker that provides according to the real-time historical data base of PI provider of this factory, adding a new ODBC at server connects, VC++6.0MFC can visit PI by the standard SQL language then, computing module is gathered a secondary data per 10 seconds, 6 groups of data of on average once being gathered in per 60 seconds, and the mean value of these 6 groups of data carried out data check, if the data check success is then brought these data into the calculating master routine, carry out boiler heating power and the grey dirty factor is calculated.Otherwise, will withdraw from computing module, the record related data reason of makeing mistakes is searched relevant error data in order to the operations staff in journal file.

3. the dirty factor of each convection heating surface ash of boiler is calculated

Calculate the dirty factor of air preheater ash, import and export the index η that flue gas pressure reduction calculates the dirty degree of air preheater heating surface ash according to the air preheater heating surface _Sj:

${\mathrm{\η}}_{\mathrm{sj}}=\frac{2\mathrm{\ΔP}}{{\left(\mathrm{wF}\right)}^2\mathrm{\ρ}}=\frac{273\mathrm{\ΔP}\·2g}{{\left(3600B_j\right)}^2{V}_y{G}_y(T+273)}=C\frac{\mathrm{\ΔP}}{B_j^2{V}_y{G}_y(T+273)};$

Calculate the grey dirty factor FF of air preheater _Ky:

${\mathrm{FF}}_{\mathrm{ky}}=\frac{{\mathrm{\η}}_{\mathrm{lx}}-{\mathrm{\η}}_{\mathrm{sj}}}{{\mathrm{\η}}_{\mathrm{lx}}}$

Wherein, Δ P is the pressure drop of this section heating surface, N/m ²B _jFor calculating Coal-fired capacity, kg/h; G _yBe 1 kilogram of coal combustion gained flue gas quality, its formula is: G _y=1-A ^Ar/ 100+1.036 α V ⁰, kg/kg; V _yBe 1 kilogram of coal combustion gained flue gas volume, m ³/ kg; ρ is a smoke density, kg/m ³W is a flue gas flow rate, m/s; F is the flue sectional area, m ²C is a constant coefficient; η _SjBe the actual computation value; η _LxBe numerical value ideally; FF _KyThe grey dirty factor for air preheater;

4. calculate the dirty factor FF of convection heating surface ash _Dl,

${\mathrm{FF}}_{\mathrm{dl}}=\frac{K_{\mathrm{lx}}-K_{\mathrm{sj}}}{K_{\mathrm{lx}}};$

Q _sj＝D(i″-i′+Δi _jw)/B _j；

$K_{\mathrm{sj}}=\frac{Q_{\mathrm{sj}}}{A\·\mathrm{\Δt}};$

More than various in: i ', i " be the steam enthalpy of heating surface import and outlet, kJ/kg; Δ i _JwBe desuperheating water enthalpy, kJ/kg; A is the heating surface heat transfer area, m ², Δ t is a heat transfer temperature difference, K; FF _DlIt is the dirty factor of convection heating surface ash; K _LxBe the desirable heat transfer coefficient of air preheater, kJ/ (m ²K); K _SjThe actual heat transfer coefficient of air preheater heating surface, kJ/ (m ²K);

5. determining of the dirty factor of critical ash

Calculating energy net proceeds at first

$Q_{\mathrm{net}}=Q_{\mathrm{in}}-Q_{\mathrm{out}}=Q_{f\_n}-Q_{f\_0}-Q_{\mathrm{out}}$

$=F(n{\∫}_{{\mathrm{\τ}}_0}^{{\mathrm{\τ}}_0+\mathrm{\Δ\τ}/n}(1-f\left(\mathrm{\τ}\right))K_{\mathrm{lx}}\mathrm{\ΔTd\τ}-{\∫}_{{\mathrm{\τ}}_0}^{{\mathrm{\τ}}_0+\mathrm{\Δ\τ}}(1-f\left(\mathrm{\τ}\right))K_{\mathrm{lx}}\mathrm{\ΔTd\τ})-n*{\mathrm{\τ}}_1*m*(I_{\mathrm{chou}}-I_0)$

Ask max (Q _Net), optimum frequency that can this top blast ash that is heated, substitution formula FF=f (τ) tries to achieve the dirty factor of the critical ash of each heating surface under the current working; Q wherein _{F_0}Be the heat during the soot blower attonity in this period, kJ; Q _{F_n}Heat when having carried out blowing ash n time for this period, kJ; Q _OutFor blowing the heat of grey steam consumption, kJ for n time; F is the heating surface heat transfer area, m ²Δ T is a logarithm mean temperature difference; F (τ) changes function for the grey dirty factor with blowing the grey frequency (time); I _ChouThe vapour source enthalpy of the used steam of soot blower, kJ/kg; I ₀Be condenser inlet enthalpy, kJ/kg;

Step 3: result of calculation storage, demonstration and historical trend inquiry

After finishing the collection of data, verification and calculating, computing module sends to real-time historical data transit module with boiler heating power result of calculation and boiler soot-blowing instruction, real-time historical data transit module is sent to the webpage configuration picture with real-time result of calculation and shows in real time, historical data is sent into SQL database, and the demonstration of webpage real time data, historical trend inquiry and the remote access module developed based on the .NET platform have realized that result of calculation shows in real time, historical trend is inquired about and remote access function.

Picture is by finishing with the configuration software configuration of VB6.0 exploitation, provide the boiler convection heating surface to blow grey information frame, each section convection heating surface (comprises back screen superheater, screen formula reheater, high temperature reheater, high temperature superheater, low temperature superheater, the state of dust stratification economizer) is divided into 3 kinds: slight pollution, intermediate pollution and serious pollution, and distinguished: yellow with three kinds of different colors, pink and red, show the grey dirty factor of this heating surface on corresponding icon top, when this icon is in redness, represent that then its corresponding fouling of heating surface is more serious, provide blowing of each heating surface grey information in the picture bottom, when pairing when blowing grey group of needs and blowing ash, its corresponding icon will become redness, play warning function.

Picture provides also that the trend map of data is browsed, query function, and the trend map of data is browsed, query function is divided into historical query and inquiry in real time:

Real-time time span is 1 hour, and the concluding time is the current computer time;

Historical query is divided into inquiry in 24 hours, inquiry in 8 hours and the inquiry of random time section, and the time span of inquiry in 24 hours is 24 hours, and the concluding time is the current computer time; The query time span was 8 hours in 8 hours, and the concluding time is the current computer time; Random time section query time span is institute's span of input inquiry beginning and ending time, and the concluding time is institute's end of input time.

Claims (5)

1. Boiler Ash fouling monitoring and soot blowing and optimal method based on an ature of coal on-line measurement is characterized in that this method comprises as lower module: measuring point data acquisition module, computing module, real-time historical data transit module, data disaply moudle; The required measuring point of this method and original measuring point data that computing module is gathered according to the measuring point module, contrary flue gas flow carries out heating power to each convection heating surface and calculates, obtain the grey dirty factor and the dirty factor of critical ash of each convection heating surface, provide and blow the ash guidance, and send result of calculation to real-time historical data transit module, the historical data transit module shows by data disaply moudle real-time result of calculation on picture in real time, and historical data is sent in the database; The measuring point data acquisition module by the newly-increased primary instrument of boiler, coal analysis instrument and newly-increased DAS system, is gathered measuring point data, and these data is sent into the real-time history data store device of boiler.

2. Boiler Ash fouling monitoring and soot blowing and optimal method based on the ature of coal on-line measurement as claimed in claim 1, it is characterized in that the measuring point data acquisition module, adopt the real-time analysis of ature of coal in-line analyzer to go into the elementary composition and the calorific value of stove fire coal, and analysis result is sent into the real-time history data store device of boiler.

3. Boiler Ash fouling monitoring and soot blowing and optimal method based on the ature of coal on-line measurement as claimed in claim 1 is characterized in that computing module comprises the steps:

Step 1: the structural parameters such as tube side, caliber, flue gas circulation area and heat exchange area that boiler body, convection recuperator are set;

Step 2: the interface function that provides by the real-time history data store device of boiler manufacturer, from boiler data storage device acquisition system desired data;

Step 3: the data of being gathered from the boiler data storage device are carried out data check, have only when all measuring point datas all at limited range, just enter the computing module master routine and calculate, otherwise, withdraw from computing module and send the data alerting signal of makeing mistakes to picture;

Step 4: calculate the flue gas physical property, the data that provide according to coal analysis instrument, when calculating 1 kilogram of fired coal combustion:

A) theoretical air volume, its formula is:

V ⁰＝0.0889(C ^ar+0.375S ^ar)+0.265H ^ar-0.0333O ^ar；

B) theoretical water steam volume, its formula is:

$V_{H_{2}O}^0=0.0124W^{\mathrm{ar}}+0.111H^{\mathrm{ar}}+0.0161V^0;$

C) theoretical nitrogen volume, its formula is: $V_{N_2}^0=0.8\frac{N^{\mathrm{ar}}}{100}+0.79V^0;$

D) theoretical three atomic gas volumes, its formula is: $V_{{\mathrm{RO}}_2}^0=1.866\frac{C^{\mathrm{ar}}}{100}+0.7\frac{S^{\mathrm{ar}}}{100};$

E) actual water vapor volume, its formula is: $V_{H_{2}O}=V_{H_{2}O}^0+0.0161(\mathrm{\α}-1)V^0;$

F) actual flue gas volume, its formula is: $V_y=V_{{\mathrm{RO}}_2}^0+V_{N_2}^0+V_{H_{2}O}+(\mathrm{\α}-1)V^0;$

G) air enthalpy can calculate by function C oldAirEnth, the ColdAirEnth function with gas or the ash temperature be the function input parameter, with gas or the ash enthalpy be the function output parameter, match 0 to 2000 ℃ air and O ₂, CO ₂, H ₂O, N ₂Deng the mean specific heat of gas and the enthalpy of 1 kilogram of ash;

H) flue gas enthalpy can be according to O ₂, CO ₂, H ₂O, N ₂Volume composition and flue-gas temperature Deng gas utilize function C oldAirEnth to calculate;

Wherein, C ^Ar, H ^Ar, O ^Ar, N ^Ar, S ^ArBe the as received basis composition of coal-fired ultimate analysis, %; W ^ArBe coal-fired ultimate analysis as received basis moisture content, %; α is an excess air coefficient, can pass through formula $\mathrm{\α}=\frac{21}{21-O_2}$ Obtain O in the formula ₂Be oxygen level in the flue gas; V ⁰Be theoretical air volume, Nm ³/ kg;

Be theoretical water steam volume, Nm ³/ kg;

Be theoretical nitrogen volume, Nm ³/ kg;

Be theoretical three atomic gas volumes, Nm ³/ kg;

Be actual water vapor volume, Nm ³/ kg; V _yBe actual flue gas volume, Nm ³/ kg;

Step 5: calculate boiler coal consumption, with the thermal efficiency and the coal-fired consumption of counter balancing method calculating boiler unit,

A) heat loss due to combustibles in refuse $q_4=\frac{7850A^{\mathrm{ar}}}{Q_r}(\frac{{\mathrm{\α}}_{\mathrm{fh}}{C}_{\mathrm{fh}}}{100-C_{\mathrm{fh}}}+\frac{{\mathrm{\α}}_{\mathrm{lz}}{C}_{\mathrm{lz}}}{100-C_{\mathrm{lz}}});$

B) heat loss due to unburned gas is for coal-powder boiler, optional q ₃=0;

C) heat loss due to exhaust gas $q_2=\frac{I_{\mathrm{py}}-{\mathrm{\α}}_{\mathrm{py}}{I}_{\mathrm{lk}}^0}{Q_r}\×(100-q_4);$

D) radiation loss $q_5=q_5^e\frac{D_e}{D};$

E) heat loss due to sensible heat in slag $q_6=\frac{A^{\mathrm{ar}}{\mathrm{\α}}_{\mathrm{lz}}{\left(\mathrm{c\θ}\right)}_{\mathrm{lz}}}{Q_r};$

F) boiler efficiency η=1-q ₂-q ₃-q ₄-q ₅-q ₆

G) the total heat of effectively utilizing of boiler

Q＝D _gq(i″ _gq-i _gs)+D _zq(i″ _zq-i′ _zq)+D _bq(i _bq-i _gs)+D _pw(i _pw-i _gs)；

H) calculate coal-fired consumption $B_j=\frac{Q}{\mathrm{\η}{Q}_r};$

A wherein ^ArBe coal-fired ultimate analysis as received basis ash, %; O _rBe that 1 kilogram of fire coal is gone into stove heat, kJ/kg; C _Fh, C _LzBe the content percentage of carbon residue in flying dust and the slag, %; α _FhBe the grey share that accounts for fuel ash in the flying dust, %; α _LzFor the ash in the slag accounts for the share of ash content in the fuel, %; I _PyBe smoke evacuation enthalpy, kJ/kg; I _Lk ⁰Be theoretical cold air enthalpy, kJ/kg; α _PyBe the excess air coefficient behind the air preheater; q ₅ ^eBe radiation loss under the boiler rating, %; D _eBe rated capacity, kg/h; D is the boiler actual evaporation, kg/h; (c θ) _LzBe the product of slag specific heat and its temperature, i.e. the enthalpy of 1 kilogram of ash when temperature θ, kJ/kg; D _GqBe superheat steam flow, kg/h; D _ZqBe reheated steam flow, kg/h; D _BqUse saturated vapour flow, kg/h for taking out; D _PwBe water amount of blowdown, kg/h; I " _GqBe superheated vapor outlet enthalpy, kJ/kg; I " _Zq, i ' _ZqBe reheated steam outlet and inlet enthalpy, kJ/kg; i _BqBe the enthalpy of saturated vapour, kJ/kg; i _PwBe sewer enthalpy, kJ/kg; i _GsBe boiler feed water enthalpy, kJ/kg;

Step 6: calculate the dirty factor of air preheater ash, import and export the index η that flue gas pressure reduction calculates the dirty degree of air preheater heating surface ash according to the air preheater heating surface _Sj:

$a),{\mathrm{\η}}_{\mathrm{sj}}=\frac{2\mathrm{\ΔP}}{{\left(\mathrm{wF}\right)}^2\mathrm{\ρ}}=\frac{273\mathrm{\ΔP}\·2g}{{\left(3600B_j\right)}^2{V}_y{G}_y(T+273)}=C\frac{\mathrm{\ΔP}}{B_j^2{V}_y{G}_y(T+273)};$

B) the grey dirty factor FF of calculating air preheater _Ky:

${\mathrm{FF}}_{\mathrm{ky}}=\frac{{\mathrm{\η}}_{\mathrm{lx}}-{\mathrm{\η}}_{\mathrm{sj}}}{{\mathrm{\η}}_{\mathrm{lx}}}$

Wherein, Δ P is the pressure drop of this section heating surface, N/m ²B _jFor calculating Coal-fired capacity, kg/h; G _yBe 1 kilogram of coal combustion gained flue gas quality, its formula is: G _y=1-A ^Ar/ 100+1.036 α V ⁰, kg/kg; V _yBe 1 kilogram of coal combustion gained flue gas volume, m ³/ kg; ρ is a smoke density, kg/m ³W is a flue gas flow rate, m/s; F is the flue sectional area, m ²C is a constant coefficient; η _SjBe the actual computation value; η _LxBe numerical value ideally; FF _KyThe grey dirty factor for air preheater;

Step 7: calculate the dirty factor FF of convection heating surface ash _Dl,

$a),{\mathrm{FF}}_{\mathrm{dl}}=\frac{K_{\mathrm{lx}}-K_{\mathrm{sj}}}{K_{\mathrm{lx}}};$

b)Q _sj＝D(i″-i′+Δi _jw)/B _j；

$c),K_{\mathrm{sj}}=\frac{Q_{\mathrm{sj}}}{A\·\mathrm{\Δt}};$

More than various in: i ', i " be the steam enthalpy of heating surface import and outlet, kJ/kg; Δ i _JwBe desuperheating water enthalpy, kJ/kg; A is the heating surface heat transfer area, m ², Δ t is a heat transfer temperature difference, K; FF _DlIt is the dirty factor of convection heating surface ash; K _LxBe the desirable heat transfer coefficient of air preheater, kJ/ (m ²K); K _SjThe actual heat transfer coefficient of air preheater heating surface, kJ/ (m ²K);

Step 8: calculate the dirty factor of furnace wall cooling ash

A) calculate furnace outlet gas temperature

B) burner hearth evenly heat coefficient of efficiency

C) the dirty factor of furnace wall cooling ash

${\mathrm{\ζ}}_{\mathrm{pj}}=\frac{{\mathrm{\ψ}}_{\mathrm{pj}}}{x_{\mathrm{pj}}};$

Wherein, T _aBe theoretical temperature combustion, K; M represents the constant of flame central position for considering the coefficient of flame central position; σ ₀Be Boltzmann constant, 5.67 * 10 ^-8, W/ (m ²K ⁴); a _lThe burner hearth blackness is the imaginary blackness of the effective radiation of an expression flame; F _LtThe burner hearth area, m ²

Protect hot coefficient; B _jComputing fuel level, kg/h; VC _PjFlue gas arrives θ at 0 ℃ " _LtBetween mean heat capacity, kJ/ (kg ℃); x _PjBe the angle factor of water screen tube, relevant with the structural arrangement of water-cooling wall;

Step 9: calculate the dirty factor of critical ash, the calculating energy net proceeds

$Q_{\mathrm{net}}=Q_{\mathrm{in}}-Q_{\mathrm{out}}=Q_{f\_n}-Q_{f\_0}-Q_{\mathrm{out}}$

$=F(n{\∫}_{{\mathrm{\τ}}_0}^{{\mathrm{\τ}}_0+\mathrm{\Δ\τ}/n}(1-f\left(\mathrm{\τ}\right))K_{\mathrm{lx}}\mathrm{\ΔTd\τ}-{\∫}_{{\mathrm{\τ}}_0}^{{\mathrm{\τ}}_0+\mathrm{\Δ\τ}}(1-f\left(\mathrm{\τ}\right))K_{\mathrm{lx}}\mathrm{\ΔTd\τ})-n^{*}{\mathrm{\τ}}_1*m*(I_{\mathrm{chou}}-I_0)$

Ask max (Q _Net), optimum frequency that can this top blast ash that is heated, substitution formula FF=f (τ) tries to achieve the dirty factor of the critical ash of each heating surface under the current working; Q wherein _{F_0}Be the heat during the soot blower attonity in this period, kJ; Q _{F_n}Heat when having carried out blowing ash n time for this period, kJ; Q _OutFor blowing the heat of grey steam consumption, kJ for n time; F is the heating surface heat transfer area, m ²Δ T is a logarithm mean temperature difference; F (τ) changes function for the grey dirty factor with blowing the grey frequency (time); I _ChouBe the vapour source enthalpy of the used steam of soot blower, kJ/kg; I ₀Be condenser inlet enthalpy, kJ/kg;

Step 10: boiler heating power result of calculation and boiler soot-blowing instruction are sent to real-time historical data transfer platform;

4. Boiler Ash fouling monitoring and soot blowing and optimal method based on the ature of coal on-line measurement as claimed in claim 1, it is characterized in that described real-time historical data transit module deposits real-time result of calculation in calculator memory, treat next result of calculation arrival constantly, previous moment data form computer internal memory is moved into database, the real time data in the update calculation machine internal memory then.

5. Boiler Ash fouling monitoring and soot blowing and optimal method based on the ature of coal on-line measurement as claimed in claim 1, it is characterized in that described data disaply moudle shows the real-time result of calculation of the dirty factor of each convection heating surface ash in real time on the icon top of correspondence, and with the state of the dust stratification of yellow, pink and red three kinds of each section of color showing convection heating surfaces:, represent with yellow icon when the dirty factor of heating surface ash is slight pollution during less than 70% the dirty factor of critical ash; When the dirty factor of heating surface ash is intermediate pollution greater than 70% the dirty factor of critical ash during less than the dirty factor of critical ash, represent with pink icon; When the dirty factor of heating surface ash is serious pollution during greater than the dirty factor of critical ash, represent with red icon, point out this top blast ash group of being heated to blow ash simultaneously.

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