CN108644754A

CN108644754A - A kind of feed temperature changes the bearing calibration to supercritical once-through boiler fuel quantity

Info

Publication number: CN108644754A
Application number: CN201810495530.6A
Authority: CN
Inventors: 王艳红; 曹丽华; 姜铁骝; 张毅; 李博; 张仲彬; 胡鹏飞; 李琪; 李盼; 司和勇; 王占洲; 潘同洋
Original assignee: Northeast Dianli University
Current assignee: Northeast Electric Power University
Priority date: 2018-05-22
Filing date: 2018-05-22
Publication date: 2018-10-12
Anticipated expiration: 2038-05-22
Also published as: CN108644754B

Abstract

The present invention is that a kind of feed temperature changes bearing calibration to supercritical once-through boiler fuel quantity, its main feature is that including air preheater exports the calculating link and burner hearth heat Balance Calculation link of economizer exit water temperature after the calculating link of hot blast temperature, feed temperature variation after basic parameter and operation and structural parameters input element, feed temperature variation.By inputting the deviation of basic parameter, operation and the structural parameters and given supercritical once-through boiler feed temperature of boiler, the air preheater outlet hot blast temperature after feed temperature variation is determined according to differential deviation method；Determine the exit water temperature of economizer after feed temperature changes；Determine that the fuel quantity after feed temperature variation, entire calculation process are carried out using iterative calculation method by burner hearth thermal balance.The quantitative accurate instruction for changing after-burning doses to supercritical once-through boiler feed temperature can be reached, coal-water ratio accurately adjusts fuel quantity after solving the problems, such as the variation of supercritical once-through boiler feed temperature.

Description

A kind of feed temperature changes the bearing calibration to supercritical once-through boiler fuel quantity

Technical field

The present invention relates to the monitoring of heat power equipment performance state and diagnostic fields, and in particular to a kind of variation of feed temperature is to super The bearing calibration of critical direct current cooker fuel quantity.

Background technology

Station boiler feed temperature is to reflect the important technology index of power plant's performance driving economy, and carry out boiler economics The important parameter of diagnosis and boiler operatiopn optimization.When super critical boiler is run within the scope of supercritical pressure, water-cooling wall is real Superheater is equivalent on border, when feed temperature changes, supercritical once-through boiler is mainly controlled by adjusting coal-water ratio Centrum's temperature processed, and then control main steam temperature.Therefore, in a sense, to superheat steam temperature variation characteristic It influences maximum to be coal-water ratio.

Supercritical once-through boiler is more sensitive for the variation of parameter.For running supercritical once-through boiler, work as pot When stove evaporation capacity and steam parameter remain unchanged, the variation of feed temperature will cause boiler oil amount to change, and then cause The variation of the smoke temperature and flue gas flow of combustion conditions and heating surface at different levels in Boiler Furnace, and finally cause exhaust gas temperature and pot The variation of the efficiency of furnace, and the variation of boiler efficiency can influence boiler oil amount in turn.Therefore, after feed temperature variation, The variation of boiler efficiency and fuel quantity is the influence process of a couple variations, and mutual influence Relationship Comparison is complicated and is It is nonlinear, and be difficult accurately to be decoupled to the two with conventional computational methods, cause feed temperature variation to direct current The quantitative instruction of boiler oil amount is indefinite, and then can not be accurately to the corresponding coal after direct current cooker feed temperature variation in operation Water than action effectively instructed, and then be unfavorable for effectively controlling centrum's temperature to stablize main steam temperature.This feelings Condition is particularly critical in terms of the excision of supercritical unit high-pressure heater and the throwing of No. zero high-pressure heater stop, and thus gives direct current The safety and economic operation of boiler controller system brings very big hidden danger.

Currently, we mark at country for the country of modified computing method Primary Reference China of boiler exterior service condition variation It is accurate《Station boiler performance test code GB/T 10184-2015》With U.S.'s boiler performance test standard《ASME PTC4-2008 Boiler performance test regulation》And《ASME PTC4.3-1968 air preheater performance test codes》In modified computing formulae into Row.But regrettably, these standards are only the modified computing methods for defining feed temperature variation to exhaust gas temperature.Not There is the modified computing method for providing feed temperature variation to boiler oil amount.

Existing feed temperature variation is all based on the above standard to the modified computing method overwhelming majority of boiler performance, still Do not overcome and solve drawbacks described above.Individual feed temperature variations are to the modified computing method of boiler performance only from feed temperature Think that the check of boiler oil amount is repaiied in a kind of approximate feed temperature variation obtained in the case that boiler efficiency is constant after variation Just, it is not fully solved the decoupling problem of fuel quantity and boiler efficiency, to can not achieve feed temperature variation to direct current pot The accurate quantitative analysis of stove fuel quantity calculates, and it is even more impossible to the adjustment of boiler side operating parameter after accurately instructing feed temperature to change.Therefore, It is unfavorable for the safety and economic operation of direct current cooker.

Invention content

For cannot accurately reflect at present direct current cooker feed temperature variation to fuel quantity quantitative effect the problem of and defect, Effectively to instruct corresponding operating of the boiler operatiopn personnel after feed temperature variation, especially in excision high-pressure heater and 0 is put into operation The action of coal-water ratio after number high-pressure heater, fume side heat exchange efficiency of the present invention in definition from furnace outlet to economizer entrance On the basis of, start with from burner hearth thermal balance, proposes that a kind of feed temperature changes to supercritical DC pot in conjunction with differential deviation theory The quantitative correction computational methods that stove fuel quantity influences must solve asking for boiler efficiency and boiler oil amount simultaneously to avoid Topic realizes the adjustment that accurate quantitative analysis instruction supercritical once-through boiler changes after-burning doses in feed temperature.

The technical solution adopted by the present invention is：A kind of correction side of the feed temperature variation to supercritical once-through boiler fuel quantity Method, characterized in that it include in have：

(a) basic parameter and operation and structural parameters input：

After the link mainly meets feed temperature variation by the input of basic parameter and the input of operating parameter instantly The calculating of corresponding operating parameter, since basic parameter and operating parameter are to determine the important parameter of fuel quantity variation, and load is not Together, basic parameter and operating parameter differ greatly, and therefore, the basic parameter and operating parameter of input must be loads instantly Operating parameter also can use design parameter under different load and be inputted as basic parameter in practical calculating；The basic parameter Including：Fuel quantity, hot air temperature, air preheater import smoke temperature, feed temperature, the air mass flow for flowing through air preheater, Flow through flue gas flow, air preheater flue gas specific heat, air preheater air specific heat, exhaust gas temperature, the burner hearth of air preheater Export smoke temperature, air preheater fume side heat exchange efficiency, the flue gas flow for flowing through economizer, economizer flue gas specific heat, water supply ratio Heat, economizer exit water temperature, economizer import smoke temperature, economizer fume side heat exchange efficiency；The operation and structural parameters include： Environment cold wind temperature, slag temperature, burner hearth cooling surface area, flying dust share, clinker share, feedwater flow, errors, coal quality Ingredient, heat loss of imperfect solid combustion, low-temperature reheater inlet steam temperature, air preheater heat transfer area, economizer pass Energy transformation ratio, pulverized coal preparation system unit power consumption, burner hearth air leakage coefficient, pulverized coal preparation system leakage in hot area, coal pulverizer mill processes Wind coefficient, furnace outlet excess air coefficient, the excess air coefficient of air preheater air side outlet and economizer exit water Pressure；

(b) calculating of air preheater outlet hot blast temperature after feed temperature changes：

Feed temperature change causes the fuel quantity of boiler to change, in the constant situation of furnace outlet excess air coefficient Under, the air mass flow for causing air preheater and flue gas flow are changed, obtained by air preheater energy-balance equation：

In formula：t_rkHot blast temperature is exported for air preheater, is first to estimate post-equalization in calculating, DEG C；η_kyFor air preheat Device fume side heat exchange efficiency；For system errors；Average excess air system is imported and exported for air preheater fume side Flue gas mass flow under several, kgh^-1；Air under average excess air coefficient is imported and exported for air preheater air side Mass flow, kgh^-1；θ′_kyFor air preheater import smoke temperature, DEG C；It is imported and exported under mean temperature for air preheater Air specific heat, kJ (kg DEG C)^-1；The flue gas specific heat under mean temperature, (kg DEG C of kJ are imported and exported for air preheater )^-1；t₀For air preheater import cold wind temperature, i.e. environment cold wind temperature, DEG C；

The air preheater fume side heat exchange efficiency of counter-flow arrangement is：

Wherein

In formula：η_kyFor air preheater fume side heat exchange efficiency；K_kyFor air preheater heat transfer coefficient, W (m²·℃ )^-1；A_kyFor air preheater heat transfer area, m²；It is imported and exported under average excess air coefficient for air preheater fume side Flue gas mass flow, kgh^-1；Air quality under average excess air coefficient is imported and exported for air preheater air side Flow, kgh^-1；θ′_kyFor air preheater import smoke temperature, DEG C；The air under mean temperature is imported and exported for air preheater Specific heat, kJ (kg DEG C)^-1；The flue gas specific heat under mean temperature, kJ (kg DEG C) are imported and exported for air preheater^-1；t₀ For air preheater import cold wind temperature, i.e. environment cold wind temperature, DEG C；θ_pyFor exhaust gas temperature, DEG C；

Theoretical according to differential deviation, the variable quantity that feed temperature variation causes air preheater to export hot blast temperature is：

In formula：Cause the variable quantity of air preheater outlet hot blast temperature for feed temperature variation, DEG C；t_fwFor pot Stove feed temperature, DEG C；t_rkHot blast temperature is exported for air preheater, is first to estimate post-equalization in calculating, DEG C；η_kyIt is pre- for air Hot device fume side heat exchange efficiency；The flue gas mass stream under average excess air coefficient is imported and exported for air preheater fume side Amount, kgh^-1；Air quality flow under average excess air coefficient, kgh are imported and exported for air preheater air side^-1； Δt_fwFor the variable quantity of feed temperature, DEG C, here,t_fw1For the feed temperature after variation,On the basis of water supply Temperature；

The flue gas mass flow flowed through under the average excess air coefficient of air preheater fume side inlet and outlet is expressed as：

In formula：The flue gas mass flow under average excess air coefficient is imported and exported for air preheater fume side, kg·h^-1；To pass through the average flue gas volume of air preheater, m³·kg^-1；To pass through air preheater mean temperature Under smoke density, kg (m³)^-1；B is boiler fired coal consumption, is first to estimate post-equalization in calculating, kgh^-1；q₄For machinery Heat loss due to incomplete combustion；

1st offset component in formula (3) is obtained by formula (1) and formula (4), i.e. air preheater exhaust gas volumn variation is drawn Playing air preheater outlet hot air temperature variable quantity is：

In formula：Air preheater is caused to export hot air temperature variation for the variation of air preheater exhaust gas volumn Amount, DEG C；To pass through the average flue gas volume of air preheater, m³·kg^-1；For by under air preheater mean temperature Smoke density, kg (m³)^-1；FootmarkTo take the relevant parameter of a reference value, t in calculating_rkHeat is exported for air preheater Air temperature is first to estimate post-equalization in calculating, DEG C；η_kyFor air preheater fume side heat exchange efficiency；For system errors；The flue gas mass flow under average excess air coefficient, kgh are imported and exported for air preheater fume side^-1；For sky Air quality flow under the average excess air coefficient of air preheater air side inlet and outlet, kgh^-1；θ′_kyFor air preheater into Mouth smoke temperature, DEG C；The air specific heat under mean temperature, kJ (kg DEG C) are imported and exported for air preheater^-1；It is pre- for air Flue gas specific heat under hot device inlet and outlet mean temperature, kJ (kg DEG C)^-1；t₀For air preheater import cold wind temperature, DEG C；To consider the correction factor of unburned carbon loss；Δt_fwFor the variable quantity of feed temperature, DEG C；Δ B is The variable quantity of fuel quantity caused by feed temperature, kgh^-1, i.e. Δ B=B₁-B⁰, wherein B₁Fuel after changing for feed temperature Amount, is first to estimate post-equalization in calculating, B⁰On the basis of fuel quantity；t₀For air preheater import cold wind temperature, DEG C；

Air preheater import smoke temperature variable quantity is：

In formula：Δθ′_kyCause the variable quantity of air preheater import smoke temperature for feed temperature variation, DEG C；θ′_sm1For water supply Economizer import smoke temperature after temperature change, DEG C；t_fw1For the feed temperature after variation, DEG C；η_sm1After changing for feed temperature Economizer fume side heat exchange efficiency；For air preheater benchmark entrance flue gas temperature, DEG C；

2nd offset component, i.e. air preheater entrance flue gas temperature in formula (3) are obtained by formula (1) and formula (6) Variation causes air preheater to export hot air temperature variable quantity：

In formula：Air preheater is caused to export hot-air temperature for the variation of air preheater entrance flue gas temperature Variable quantity is spent, DEG C；t_fwFor boiler feed temperature, DEG C；t_rkHot blast temperature is exported for air preheater, is after first estimating in calculating Correction, DEG C；θ′_kyFor air preheater import smoke temperature, DEG C；η_kyFor air preheater fume side heat exchange efficiency；For system thermal protection Coefficient；The flue gas mass flow under average excess air coefficient, kgh are imported and exported for air preheater fume side^-1；Air quality flow under average excess air coefficient, kgh are imported and exported for air preheater air side^-1；It is pre- for air Air specific heat under hot device inlet and outlet mean temperature, kJ (kg DEG C)^-1；It is imported and exported under mean temperature for air preheater Flue gas specific heat, kJ (kg DEG C)^-1；Δθ′_kyCause the variable quantity of air preheater import smoke temperature for feed temperature variation, ℃；

3rd offset component in formula (3), air preheater fume side heat exchange efficiency are obtained by formula (1) and formula (2) Variation causes air preheater to export hot air temperature variable quantity：

In formula：Air preheater is caused to export hot-air for the variation of air preheater fume side heat exchange efficiency Temperature variation, DEG C；t_fwFor boiler feed temperature, DEG C；t_rkHot blast temperature is exported for air preheater, is first to estimate in calculating Post-equalization, DEG C；Δt_fwFor the variable quantity of feed temperature, DEG C；θ′_kyFor air preheater import smoke temperature, DEG C；η_kyFor air preheat Device fume side heat exchange efficiency；For system errors；Average excess air coefficient is imported and exported for air preheater fume side Under flue gas mass flow, kgh^-1；Air matter under average excess air coefficient is imported and exported for air preheater air side Measure flow, kgh^-1；The air specific heat under mean temperature, kJ (kg DEG C) are imported and exported for air preheater^-1；For sky Air preheater imports and exports the flue gas specific heat under mean temperature, kJ (kg DEG C)^-1；Δη_kyIt is front and back empty to change for feed temperature The difference of air preheater fume side heat exchange efficiency, i.e. Δ η_ky=η_ky1-η_ky, η_ky1Air preheater cigarette after changing for feed temperature Gas side heat exchange efficiency, η_kyAir preheater fume side heat exchange efficiency before changing for feed temperature；t₀For air preheater import Cold wind temperature, DEG C；

The air quality flow for flowing through air preheater is：

In formula：q_m(kq)To flow through the air quality flow of air preheater, kg/s；It is flat for air preheater air side Equal excess air coefficient；V⁰For theoretical air requirement, m³·kg^-1；B is boiler fired coal consumption, is first to estimate post-equalization in calculating, kg·h^-1；q₄For heat loss due to combustibles in refuse；

4th offset component in formula (3) is obtained by formula (1) and formula (9), i.e. air preheater air mass flow changes Cause air preheater outlet hot air temperature variable quantity be：

In formula：Cause air preheater to export hot air temperature for the variation of air preheater air mass flow to become Change amount, DEG C；t_fwFor boiler feed temperature, DEG C；t_rkHot blast temperature is exported for air preheater, is first to estimate post-equalization in calculating, ℃；Δt_fwFor the variable quantity of feed temperature, DEG C；θ′_kyFor air preheater import smoke temperature, DEG C；η_kyFor air preheater fume side Heat exchange efficiency；For system errors；The cigarette under average excess air coefficient is imported and exported for air preheater fume side Gas mass flow, kgh^-1；Air quality flow under average excess air coefficient is imported and exported for air preheater air side, kg·h^-1；The air specific heat under mean temperature, kJ (kg DEG C) are imported and exported for air preheater^-1；For air preheat Device imports and exports the flue gas specific heat under mean temperature, kJ (kg DEG C)^-1；To cause air preheat for feed temperature variation The changing value of device air mass flow, kgh^-1；To consider the correction factor of unburned carbon loss；For sky Air preheater air side is averaged excess air coefficient；V⁰For theoretical air requirement, m³·kg^-1；B is boiler fired coal consumption, kgh^-1；Δ B is the variable quantity of fuel quantity, kgh^-1；t₀For air preheater import cold wind temperature, i.e. environment cold wind temperature, DEG C；

Air preheater after variation exports hot air temperature：

In formula：t_rk1Air preheater after changing for feed temperature exports hot air temperature, DEG C；On the basis of air it is pre- Hot device outlet air temperature, DEG C；Cause the variable quantity of air preheater outlet hot air temperature for feed temperature variation, ℃。

(c) calculating of economizer exit water temperature after feed temperature changes：

After feed temperature variation, economizer heat-transfer character is caused to change, causes economizer exit water temperature to change, economizer energy Measuring equilibrium equation is：

In formula：t_smcFor economizer exit water temperature, DEG C；For system errors；η_smFor economizer fume side heat exchange efficiency； θ′_smFor economizer input gas temperature, DEG C；q_m(gs)For economizer feed-water quality flow, kgh^-1；It is imported and exported for economizer Water supply specific heat under water mean temperature, kJ (kg DEG C)^-1；It is imported and exported under average excess air coefficient for economizer fume side Flue gas mass flow, kgh^-1；The flue gas specific heat under average flue-gas temperature, (kg DEG C of kJ are imported and exported for economizer )^-1；tf_wFor boiler feed temperature, DEG C；

Wherein, the fume side heat exchange efficiency of economizer is：

Wherein

In formula：η_smFor economizer fume side heat exchange efficiency；θ′_smFor economizer input gas temperature, DEG C；K_smFor economizer Heat transfer coefficient, kW (m²·℃)^-1；A_smFor economizer heat transfer area, m²；q_m(gs)For economizer feed-water quality flow, kgh^-1；Water supply specific heat under water mean temperature, kJ (kg DEG C) are imported and exported for economizer^-1；It is passed in and out for economizer fume side Flue gas mass flow under the average excess air coefficient of mouth, kgh^-1；The cigarette under average flue-gas temperature is imported and exported for economizer Gas specific heat, kJ (kg DEG C)^-1；θ′_kyFor air preheater import smoke temperature, DEG C；t_fwFor boiler feed temperature, DEG C；

It is theoretical according to differential deviation, boiler feed temperature variation is obtained by formula (10), economizer exit water temperature is caused to change Amount is：

In formula：Cause the variable quantity of economizer exit coolant-temperature gage for feed temperature variation, DEG C；t_smcFor economizer Exit water temperature, DEG C；Δt_fwFor the variable quantity of feed temperature, DEG C；Average excess air system is imported and exported for economizer fume side Flue gas mass flow under several, kgh^-1；η_smFor economizer fume side heat exchange efficiency；θ′_smFor economizer input gas temperature, ℃；t_fwFor boiler feed temperature, DEG C；

Wherein, the 1st offset component in formula (14) is obtained by formula (12), i.e. feed temperature variation directly causes province Coal device exit water temperature variable quantity is：

In formula：Directly cause the variable quantity of economizer exit coolant-temperature gage for feed temperature variation, DEG C；t_smcTo save Coal device exit water temperature, DEG C；Δt_fwFor the variable quantity of feed temperature, DEG C；It is imported and exported for economizer fume side average excessive empty Flue gas mass flow under gas coefficient, kgh^-1；η_smFor economizer fume side heat exchange efficiency；It is average for economizer inlet and outlet Flue gas specific heat under flue-gas temperature, kJ (kg DEG C)^-1；q_m(gs)For economizer feed-water quality flow, kgh^-1；To save coal Device imports and exports water supply specific heat under water mean temperature, kJ (kg DEG C)^-1；For system errors；

In formula：To pass through the average flue gas volume of economizer, m³·kg^-1；To pass through the mean temperature of economizer Under smoke density, kgm^-3；B is boiler fired coal consumption, is first to estimate post-equalization in calculating, kgh^-1；q₄Not for machinery Completely burned heat loss；

2nd offset component in formula (14) is obtained by formula (12) and formula (16), i.e. feed temperature variation leads to province Coal device exhaust gas volumn changes, and causes the economizer exit water temperature variable quantity to be：

In formula：Cause economizer exhaust gas volumn to change for feed temperature variation, causes economizer exit water The variable quantity of temperature, DEG C；To pass through the average flue gas volume of economizer, m³·kg^-1；To pass through the mean temperature of economizer Under smoke density, kgm^-3；t_smcFor economizer exit water temperature, DEG C；Δt_fwFor the variable quantity of feed temperature, DEG C；For Flue gas mass flow under the average excess air coefficient of economizer fume side inlet and outlet, kgh^-1；η_smIt is changed for economizer fume side The thermal efficiency；The flue gas specific heat under average flue-gas temperature, kJ (kg DEG C) are imported and exported for economizer^-1；q_m(gs)It is given for economizer Water quality flow, kgh^-1；Water supply specific heat under water mean temperature, kJ (kg DEG C) are imported and exported for economizer^-1；To be System errors；θ′_smFor economizer input gas temperature, DEG C；Δ B is the variable quantity of fuel quantity, kgh^-1；For Consider the correction factor of unburned carbon loss；

After feed temperature variation, the fume side heat exchange efficiency from furnace outlet to economizer entrance is defined, and be approximately considered Fume side heat exchange efficiency from furnace outlet to economizer entrance is constant, obtains economizer entrance flue gas temperature variable quantity and is：

In formula：Δθ′_smFor economizer entrance flue gas temperature variable quantity, DEG C；On the basis of economizer entrance flue gas temperature, ℃；On the basis of furnace outlet gas temperature, DEG C；Change rear hearth for feed temperature and exports smoke temperature, DEG C；After feed temperature variation Furnace outlet gas temperature is first to estimate post-equalization in calculating, t_dzrFor low-temperature reheater inlet steam temperature, DEG C；

Method is calculated specified in calculation basis China boiler controller system thermodynamic computing standard of furnace outlet gas temperature,

In formula：Change rear hearth for feed temperature and exports smoke temperature, DEG C；T_aFor theoretical temperature combustion, DEG C, T_a=Q_ar.net (1-(q₃+q₆)/(100-q₄))；σ_oIt grows rigorously constant for bohr, σ_o=5.67 × 10^-11, kW (m²·K⁴)^-1；a₁It is black for burner hearth Degree；φ is water-cooling wall thermal effective coefficient；F₁For water-cooling wall heat exchange area, m²；q₃For the imperfect combustion heat loss of gas, the value compared with It is small, it can use 0；q₆For heat loss due to sensible heat in slag, the value is smaller, can use 0；For system errors；B is boiler fired coal consumption, Post-equalization, kgh are first estimated in calculating^-1；Mean heat capacity for water cooling from furnace outlet gas temperature to theoretical temperature combustion, kJ·(kg·℃)^-1；To consider the correction factor of unburned carbon loss；M repaiies for flame central position Positive coefficient, M=A-B (X_b+ Δ x), X_bFor burner arrangement height and furnace height ratio；Δ x is that flame peak temperature is opposite Position correction value, for burner front and back wall cross collocation, Δ x=0.05, for Terms of Corner Tangential Combustion, Δ x=0；It is right In bituminous coal and lignite, A=0.59, B=0.5, for anthracite and meager coal, A=0.56, B=0.5,

3rd offset component in formula (14) is obtained by formula (12) and formula (18), i.e. feed temperature variation leads to province Coal device entrance flue gas temperature changes, and then causes the economizer exit water temperature variable quantity to be：

In formula：Cause economizer entrance flue gas temperature to change for feed temperature variation, and then causes province's coal Device exit water temperature variable quantity, DEG C；t_smcFor economizer exit water temperature, DEG C；Δt_fwFor the variable quantity of feed temperature, DEG C；To save Flue gas mass flow under the average excess air coefficient of coal device fume side inlet and outlet, kgh^-1；η_smIt exchanges heat for economizer fume side Efficiency；The flue gas specific heat under average flue-gas temperature, kJ (kg DEG C) are imported and exported for economizer^-1；q_m(gs)For economizer water supply Mass flow, kgh^-1；Water supply specific heat under water mean temperature, kJ (kg DEG C) are imported and exported for economizer^-1；It is protected for system Hot coefficient；θ′_smFor economizer input gas temperature, DEG C；Δθ′_smFor economizer entrance flue gas temperature variable quantity, DEG C；

4th offset component in formula (14) is obtained by formula (12) and formula (13), i.e., is exchanged heat by economizer fume side Efficiency change causes the economizer exit water temperature variable quantity to be：

In formula：To cause economizer exit water temperature variable quantity by the variation of economizer fume side heat exchange efficiency, ℃；The flue gas mass flow under average excess air coefficient, kgh are imported and exported for economizer fume side^-1；To save coal Flue gas specific heat under the average flue-gas temperature of device inlet and outlet, kJ (kg DEG C)^-1；q_m(gs)For economizer feed-water quality flow, kg h^-1；Water supply specific heat under water mean temperature, kJ (kg DEG C) are imported and exported for economizer^-1；For system errors；θ′_smFor Economizer input gas temperature, DEG C；t_fwFor boiler feed temperature, DEG C；Δη_smChange front and back economizer fume side for feed temperature The difference of heat exchange efficiency, i.e.,η_sm1Economizer fume side heat exchange efficiency after changing for feed temperature,For Benchmark economizer fume side heat exchange efficiency；

Feed temperature variation after economizer exit coolant-temperature gage be：

In formula：t_smc1Economizer exit water temperature after changing for feed temperature, DEG C；Cause for feed temperature variation The variable quantity of economizer exit coolant-temperature gage, DEG C；On the basis of economizer exit coolant-temperature gage, DEG C；

(d) burner hearth thermal balance：

Boiler furnace is an opening therrmodynamic system, under steady working condition, after feed temperature variation, and boiler furnace thermal balance relationship For：

Q_rl+Q_wl+Q_rk+Q_lk+Q_j=Q_yq+Q_hz+Q_f+Q_sr+Q_q4 (23)

In formula：Q_rlTo be sent into the fuel total amount of heat of burner hearth, kJh^-1；Q_wlTo enter the fuel physical sensible heat of burner hearth, kJ h^-1；Q_rkThe heat that hot-air brings burner hearth into, kJh are exported for air preheater^-1；Q_lkTo leak into the heat of burner hearth cold air carrying Amount, kJh^-1；Q_jTo bring the heat of burner hearth, kJh by the conversion of coal-grinding component mechanical energy^-1；Q_yqIt is taken out of for furnace outlet flue gas Heat, kJh^-1；Q_hzFor the heat that burner hearth flying dust and slag are taken out of, kJh^-1；Q_fFor working medium radiation absorption heat in burner hearth Amount, kJh^-1；Q_srFor burner hearth radiation loss heat, kJh^-1；Q_q4For heat of the carbon particle with flake hearth-tapping of unburned burn-up, kJ·h^-1；

1) boiler furnace inputs heat

Be sent into burner hearth fuel total amount of heat be：

In formula：Q_rlTo be sent into the fuel total amount of heat of burner hearth, kJh^-1；B is boiler fired coal consumption, after first estimating in calculating Correction, kgh^-1；Q_ar.grFor coal As-received high calorific power, kJkg^-1；To consider unburned carbon loss Correction factorQ in stable operation under the same load of boiler₄Variation is smaller, can use constant；

Fuel physical sensible heat into burner hearth is：

Q_wl=Bc_p.art_r (25)

In formula：Q_wlTo enter the fuel physical sensible heat of burner hearth, kJh^-1；B is boiler fired coal consumption, is first estimated in calculating Post-equalization, kgh^-1；c_p.arFor coal As-received specific heat at constant pressure, kJ (kg DEG C)^-1；t_rThe temperature of coal when to be sent into burner hearth, Environment temperature is taken, DEG C；

Air preheater outlet hot-air brings the heat of burner hearth into and is：

Q_rk=B β "_kyV⁰(ct)_rk (26)

In formula：Q_rkThe heat that hot-air brings burner hearth into, kJh are exported for air preheater^-1；B consumes for boiler fired coal Amount, first estimates post-equalization, kgh in calculating^-1；β″_kyFor the excess air coefficient of air preheater air side outlet；V⁰It is theoretical empty Tolerance, m³·kg^-1；(ct)_rkFor 1m³Humid air is in temperature t_rkDEG C when enthalpy, kJm^-3；

Theoretical air requirement is：

In formula：V⁰For theoretical air requirement, m³·kg^-1；C_arFor As-received carbon content, %；S_arFor As-received sulfur content, %； H_arFor As-received hydrogen content, %；O_arFor As-received oxygen content, %；

It leaks into burner hearth cold air and brings burner hearth heat into and be：

Q_lk=B Δ α V⁰(ct)_lk (28)

In formula：Q_lkTo leak into the heat of burner hearth cold air carrying, kJh^-1；B is boiler fired coal consumption, in calculating first Estimate post-equalization, kgh^-1；Δ α be burner hearth and pulverized coal preparation system air leakage coefficient and；(ct)_lkFor every 1m³Humid air is in temperature t_lk℃ Shi Han, kJm^-3；V⁰For theoretical air requirement, m³·kg^-1；

Bringing burner hearth heat by the conversion of coal-grinding component mechanical energy is：

Q_j=3.6BK_jE (29)

In formula：Q_jTo bring the heat of burner hearth, kJh by the conversion of coal-grinding component mechanical energy^-1；B is boiler fired coal consumption, Post-equalization, kgh are first estimated in calculating^-1；K_jFor energy transformation ratio in coal pulverizer mill processes；E is pulverized coal preparation system unit power consumption, Definite value, kWh t are essentially in stable operation^-1；

2) boiler furnace inputs heat

Furnace outlet flue gas takes heat out of：

In formula：Q_yqFor the heat that furnace outlet flue gas is taken out of, kJh^-1；B is boiler fired coal consumption, is first estimated in calculating Post-equalization, kgh^-1；To consider the correction factor of unburned carbon loss；For theoretical flue gas enthalpy, kJ·kg^-1；V⁰For theoretical air requirement, m³·kg^-1；a_ltFor furnace outlet excess air coefficient；(cθ)_ltFor 1m³Humid air is in stove Thorax exit gas temperature θ_ltDEG C when enthalpy, kJm^-3；

Theoretical flue gas enthalpy is：

In formula：For theoretical flue gas enthalpy, kJkg^-1；V_RO2For three atomic gas volumes, m³·kg^-1；For theoretical nitrogen Volume, m³·kg^-1；For theoretical water vapor volume, m³·kg^-1；Respectively 1m³Three atom gas Body, nitrogen and vapor are in flue gas temperature of hearth outlet θ_ltDEG C when enthalpy, kJm^-3；

Burner hearth flying dust and slag take sensible heat amount out of:

In formula：Q_hzFor the heat that burner hearth flying dust and slag are taken out of, kJh^-1；B is boiler fired coal consumption, in calculating first Estimate post-equalization, kgh^-1；A_arFor coal As-received ash content, %；a_fhFor flying dust share；(cθ)_ltIn temperature it is θ for 1kg flying dusts_ltWhen Enthalpy, kJkg^-1；a_lzFor clinker share；(cθ)_lzIn temperature it is θ for 1kg slags_lzWhen enthalpy, kJkg^-1；Q_ar.netFor coal Net calorific value as received basis, kJkg^-1；q₄For heat loss due to combustibles in refuse；

Working medium radiation absorption heat is in burner hearth：

Q_f=q_m(gs)(h_fl-h_smc) (33)

In formula：Q_fFor working medium radiation absorption heat, kJh in burner hearth^-1；q_m(gs)For economizer feed-water quality flow, kg h^-1；h_flFor working medium enthalpy in direct current cooker separator, intermediate point enthalpy is arrange parameter in operation, kJkg^-1；h_smcTo save coal Device goes out saliva enthalpy, is determined by feed temperature and feed pressure, kJkg^-1；

It is imperfect combustion fall charcoal particle band flake hearth-tapping heat be：

In formula：For heat of the carbon particle with flake hearth-tapping of unburned burn-up, kJh^-1；B is boiler fired coal consumption, meter Post-equalization, kgh are first estimated in calculation^-1；Q_ar.netFor coal net calorific value as received basis, kJkg^-1；q₄For mechanical incomplete combustion Heat loss；

System radiating loses heat：

In formula：Q_srFor burner hearth radiation loss heat, kJh^-1；S_hdsFor burner hearth cooling surface area, m²；a_cIt conducts heat for convection current Coefficient, W (m²·℃)^-1；a_fFor radiation heat transfer coefficient, W (m²·℃)^-1；a_c' it is convective heat-transfer coefficient and radiant heat transfer system The sum of number, W (m²·℃)^-1；t_hdsFor burner hearth outer surface mean temperature, DEG C；t₀For air preheater import cold wind temperature, i.e., Environment cold wind temperature, DEG C；Δ t=t_hds-t₀For the difference of burner hearth hull-skin temperature and ambient air temperature, DEG C, which generally makes even 10 DEG C of mean temperature difference empirical value is calculated；

It is obtained by formula (23)-formula (35)

In formula：B is boiler fired coal consumption, and post-equalization, kgh are first estimated in calculating^-1；Q_ar.gr1It is received for what is newly calculated Base high calorific power, kJkg^-1；To consider that the correction factor of unburned carbon loss, boiler stablize fortune Q in row₄Variation is smaller, can use constant；Q_rlTo be sent into the fuel total amount of heat of burner hearth, kJh^-1；Q_wlTo enter the fuel object of burner hearth Manage sensible heat, kJh^-1；Q_rkThe heat that hot-air brings burner hearth into, kJh are exported for air preheater^-1；Q_lkTo leak into the cold sky of burner hearth The heat that gas carries, kJh^-1；Q_jTo bring the heat of burner hearth, kJh by the conversion of coal-grinding component mechanical energy^-1；Q_yqGo out for burner hearth The heat that mouth flue gas is taken out of, kJh^-1；Q_hzFor the heat that burner hearth flying dust and slag are taken out of, kJh^-1；Q_fFor working medium spoke in burner hearth Penetrate absorption heat, kJh^-1；Q_srFor burner hearth radiation loss heat, kJh^-1；For the carbon particle band flake hearth-tapping of unburned burn-up Heat, kJh^-1。

A kind of it is proposed of feed temperature variation of the present invention to the bearing calibration of supercritical once-through boiler fuel quantity, based on Lower design：

1. theory and practice confirms, after feed temperature variation, the caloric receptivity of evaporating heating surface in boiler furnace will be caused Change, for ensure boiler output and steam parameter it is constant, must just change input boiler fuel quantity, at this moment will cause pot The flue-gas temperature and flue gas flow of stove heating surfaces at different levels change, and then lead to the change of exhaust gas temperature and boiler efficiency Change, and boiler efficiency can influence fuel quantity in turn, therefore, to accurately reflect instruction of the feed temperature variation to fuel quantity Relationship, it is necessary to which the influence relationship between boiler efficiency and fuel quantity decouples, that is, avoids direct solution boiler effect The problem of rate；

2. after feed temperature changes, the flue-gas temperature of boiler heating surfaces at different levels and flue gas flow is caused to change, this When, economizer exit water temperature and air preheater outlet hot blast temperature can also change, these factors can all cause stove internal combustion The variation of operating mode is burnt, and then leads to the variation of stove internal combustion doses.Therefore, to the fuel after accurately determining feed temperature variation Amount just firstly the need of the economizer exit water temperature and air preheater outlet hot blast temperature after determining feed temperature variation, and is wanted It calculates economizer exit water temperature and air preheater after feed temperature variation and exports hot blast temperature, need to know that feed temperature becomes Furnace outlet gas temperature after change, however to determine the furnace outlet gas temperature after feed temperature variation, it needs to know water supply in advance Boiler oil amount after temperature change, therefore, entire calculating process meets the thought of iterative calculation；

3. after feed temperature changes, cause the change of boiler oil amount, at this moment causes the heat exchange in boiler furnace first It changes, and causes boiler smoke temperature and flow through the variation of boiler heating surface exhaust gas volumns at different levels, consider to water temperature to be accurate Degree variation exports economizer exit water temperature and air preheater the influence of hot blast temperature, and present invention introduces economizer and air are pre- Hot device fume side heat exchange efficiency, and think to flow through that the variation of the flue-gas temperature and exhaust gas volumn of economizer and air preheater has been drawn The variation of economizer and air preheater fume side heat exchange efficiency has been played, and then also economizer exit water temperature and air will have been caused pre- The variation of hot device outlet hot blast temperature；

4. after feed temperature changes, cause the change of boiler oil amount, and then leads to economizer exit water temperature and air Preheater exports the variation of hot blast temperature.To simplify the calculation, definition is changed from furnace outlet to the fume side of economizer inlet flue duct The thermal efficiency, and when thinking that boiler load does not change, the fume side heat exchange efficiency from furnace outlet to economizer inlet flue duct is constant, Therefore can be the province that can determine after feed temperature variation according to the fume side heat exchange efficiency from furnace outlet to economizer inlet flue duct Coal device import smoke temperature, this simplified processing greatly improve calculating speed.

A kind of feed temperature of the present invention changes：

1. after feed temperature changes, cause the change of boiler oil amount, and causes boiler smoke temperature and flow through boiler The variation of heating surface exhaust gas volumns at different levels, it is presently believed that the economizer exit water temperature and air preheater of boiler back end ductwork go out The variation of mouth hot blast temperature can will influence the combustion case of boiler furnace again in turn.Therefore, boiler is fired in feed temperature variation The influence of doses is a global influence process, is not the influence process of a part；

2. the structure of entire algorithm uses burner hearth thermal balance, and changes by differential deviation theoretical analysis and calculation feed temperature Cause the variable quantity of relevant parameter, and in calculation basis China boiler controller system thermodynamic computing standard of furnace outlet gas temperature therein Defined method is calculated；

3. to make calculating process simplify, the fume side heat exchange efficiency from furnace outlet to economizer inlet flue duct is defined, Therefore after being assured that feed temperature variation according to the fume side heat exchange efficiency from furnace outlet to economizer inlet flue duct Economizer import smoke temperature, you can determine the economizer exit water temperature after feed temperature variation and air preheater outlet hot wind temperature Degree；

4. entire calculating process estimates pot first using iterative calculation method that is, after knowing the variable quantity of feed temperature Stove fuel quantity, air preheater outlet hot air temperature and furnace outlet gas temperature, then according to the boiler oil being newly calculated Amount, air preheater outlet hot blast temperature and furnace outlet gas temperature, and be compared with estimated value, it is given when absolute error is less than Precision when, it is believed that calculating terminate.

The present invention relates to a kind of feed temperatures to change the bearing calibration to direct current cooker fuel quantity, with quantifying for the prior art Analysis method is compared, and considers that algorithm conception is ingenious, and computational methods are scientific and reasonable and accurate, and can realize feed temperature comprehensively Change the precise calibration to supercritical once-through boiler fuel quantity, it is possible thereby to accurately instruct supercritical once-through boiler feed temperature The adjustment of coal-water ratio after variation, in favor of the safety and economic operation of boiler.

Description of the drawings

A kind of bearing calibration flow chart of the feed temperature variation of Fig. 1 present invention to supercritical once-through boiler fuel quantity；

A kind of feed temperature variation of Fig. 2 present invention solves flow to the bearing calibration algorithm of supercritical once-through boiler fuel quantity Figure；

A kind of bearing calibration program simplification flow of the feed temperature variation of Fig. 3 present invention to supercritical once-through boiler fuel quantity Figure.

Specific implementation mode

The invention will be further described with example below in conjunction with the accompanying drawings.

Referring to Fig.1~Fig. 3, a kind of feed temperature of the invention change the correction side to supercritical once-through boiler fuel quantity Method is mainly made of following several links, and combines Fig. 2 and Fig. 3, the realization of each link need the thought checked by iteration come It completes.

(a) basic parameter and operation and structural parameters input element：

After the link mainly meets feed temperature variation by the input of basic parameter and the input of operating parameter instantly The calculating of corresponding operating parameter, since basic parameter and operating parameter are to determine the important parameter of fuel quantity variation, and load is not Together, basic parameter and operating parameter differ greatly, and therefore, the basic parameter and operating parameter of input must be loads instantly Operating parameter also can use design parameter under different load and be inputted as basic parameter in practical calculating.

The basic parameter includes：Fuel quantity, hot air temperature, feed temperature, flow through sky at air preheater import smoke temperature The air mass flow of air preheater, the flue gas flow for flowing through air preheater, air preheater flue gas specific heat, air preheater air Specific heat, furnace outlet gas temperature, air preheater fume side heat exchange efficiency, the flue gas flow for flowing through economizer, saves coal at exhaust gas temperature Device flue gas specific heat, water supply specific heat, economizer exit water temperature, economizer import smoke temperature, economizer fume side heat exchange efficiency.

1 input reference parameter list of table

Equivalent fuel amount (kgh^-1)	Baseline air preheater flue gas specific heat (kJ (kg DEG C)^-1)
		Benchmark hot air temperature (DEG C)	Baseline air preheater air specific heat (kJ (kg DEG C)^-1)
Baseline air preheater import smoke temperature (DEG C)	Benchmark exhaust gas temperature (DEG C)
		Benchmark feed temperature (DEG C)	Benchmark furnace outlet gas temperature (DEG C)
Air mass flow (the kgh of baseline air preheater^-1)	Baseline air preheater flue gas side heat exchange efficiency (DEG C)
		Flue gas flow (the kgh of baseline air preheater^-1)	Flue gas flow (the kgh of benchmark economizer^-1)
Benchmark economizer flue gas specific heat (kJ (kg DEG C)^-1)	Benchmark water supply specific heat (kJ (kg DEG C)^-1)
		Benchmark economizer exit water temperature (DEG C)	Benchmark economizer import smoke temperature (DEG C)
Benchmark economizer fume side heat exchange efficiency

The operation and structural parameters include：Environment cold wind temperature, slag temperature, burner hearth cooling surface area, flying dust share, Clinker share, feedwater flow, errors, coal elemental composition, heat loss of imperfect solid combustion, low-temperature reheater inlet steam temperature Energy transformation ratio, pulverized coal preparation system list in degree, air preheater heat transfer area, economizer heat transfer area, coal pulverizer mill processes Position power consumption, burner hearth air leakage coefficient, pulverized coal preparation system air leakage coefficient, furnace outlet excess air coefficient, air preheater air side go out The excess air coefficient and economizer exit water pressure of mouth.

The input of table 2 operation and structural parameters inventory

Environment cold wind temperature (DEG C)	Errors
		Slag temperature (DEG C)	Coal elemental composition (%)
Burner hearth cooling surface area (m²)	Heat loss of imperfect solid combustion (%)
		Flying dust share	Low-temperature reheater inlet steam temperature (DEG C)
Clinker share	Air preheater heat transfer area (m²)
		Feedwater flow (kgh^-1)	Economizer heat transfer area (m²)
Energy transformation ratio in coal pulverizer mill processes	Pulverized coal preparation system unit power consumption (kWh t^-1)
		Burner hearth air leakage coefficient	Furnace outlet excess air coefficient
The excess air coefficient of air preheater air side outlet	Economizer exit water pressure (MPa)
		Pulverized coal preparation system air leakage coefficient

(b) the calculating link of air preheater outlet hot blast temperature after feed temperature changes：

Feed temperature change causes the fuel quantity of boiler to change, in the constant situation of furnace outlet excess air coefficient Under, the air mass flow for causing air preheater and flue gas flow are changed.It is obtained by air preheater energy-balance equation：

In formula：t_rkHot blast temperature is exported for air preheater, is first to estimate post-equalization in calculating, DEG C；η_kyFor air preheat Device fume side heat exchange efficiency；For system errors；Average excess air system is imported and exported for air preheater fume side Flue gas mass flow under several, kgh^-1；Air under average excess air coefficient is imported and exported for air preheater air side Mass flow, kgh^-1；θ′_kyFor air preheater import smoke temperature, DEG C；It is imported and exported under mean temperature for air preheater Air specific heat, kJ (kg DEG C)^-1；The flue gas specific heat under mean temperature, (kg DEG C of kJ are imported and exported for air preheater )^-1；t₀For air preheater import cold wind temperature, as environment cold wind temperature, DEG C；

Wherein

In formula：η_kyFor air preheater fume side heat exchange efficiency；K_kyFor air preheater heat transfer coefficient, W (m²·℃ )^-1；A_kyFor air preheater heat transfer area, m²；It is imported and exported under average excess air coefficient for air preheater fume side Flue gas mass flow, kgh^-1；Air quality under average excess air coefficient is imported and exported for air preheater air side Flow, kgh^-1；θ′_kyFor air preheater import smoke temperature, DEG C；The air under mean temperature is imported and exported for air preheater Specific heat, kJ (kg DEG C)^-1；The flue gas specific heat under mean temperature, kJ (kg DEG C) are imported and exported for air preheater^-1；t₀ It is environment cold wind temperature for air preheater import cold wind temperature, DEG C；θ_pyFor exhaust gas temperature, DEG C；

The flue gas exhaust gas volumn for flowing through air preheater is represented by：

1st offset component in formula (3) can be obtained by formula (1) and formula (4), i.e. air preheater exhaust gas volumn changes Cause air preheater outlet hot air temperature variable quantity be：

In formula：Air preheater is caused to export hot air temperature variation for the variation of air preheater exhaust gas volumn Amount, DEG C；To pass through the average flue gas volume of air preheater, m³·kg^-1；For by under air preheater mean temperature Smoke density, kg (m³)^-1；FootmarkTo take the relevant parameter of a reference value, t in calculating_rkHeat is exported for air preheater Air temperature is first to estimate post-equalization in calculating, DEG C；η_kyFor air preheater fume side heat exchange efficiency；For system errors；The flue gas mass flow under average excess air coefficient, kgh are imported and exported for air preheater fume side^-1；For sky Air quality flow under the average excess air coefficient of air preheater air side inlet and outlet, kgh^-1；θ′_kyFor air preheater into Mouth smoke temperature, DEG C；The air specific heat under mean temperature, kJ (kg DEG C) are imported and exported for air preheater^-1；It is pre- for air Flue gas specific heat under hot device inlet and outlet mean temperature, kJ (kg DEG C)^-1；t₀For air preheater import cold wind temperature, DEG C； To consider the correction factor of unburned carbon lossΔt_fwFor the variable quantity of feed temperature, DEG C；Δ B is The variable quantity of fuel quantity caused by feed temperature, kgh^-1, i.e. Δ B=B₁-B⁰, wherein B₁Fuel after changing for feed temperature Amount, is first to estimate post-equalization in calculating, B⁰On the basis of fuel quantity；t₀For air preheater import cold wind temperature, DEG C；

Air preheater import smoke temperature variable quantity is：

In formula：Δθ_k′_yCause the variable quantity of air preheater import smoke temperature for feed temperature variation, DEG C；θ′_sm1For water supply Economizer import smoke temperature after temperature change, DEG C；t_fw1For the feed temperature after variation, DEG C；η_sm1After changing for feed temperature Economizer fume side heat exchange efficiency；For air preheater benchmark entrance flue gas temperature, DEG C；

2nd offset component, i.e. air preheater inlet flue gas temperature in formula (3) can be obtained by formula (1) and formula (6) Degree variation causes air preheater to export hot air temperature variable quantity：

3rd offset component in formula (3), air preheater fume side heat exchange effect can be obtained by formula (1) and formula (2) Rate variation causes air preheater to export hot air temperature variable quantity：

In formula：Air preheater is caused to export hot-air for the variation of air preheater fume side heat exchange efficiency Temperature variation, DEG C；t_fwFor boiler feed temperature, DEG C；t_rkHot blast temperature is exported for air preheater, is first to estimate in calculating Post-equalization, DEG C；Δt_fwFor the variable quantity of feed temperature, DEG C；θ′_kyFor air preheater import smoke temperature, DEG C；η_kyFor air preheat Device fume side heat exchange efficiency；For system errors；Average excess air system is imported and exported for air preheater fume side Flue gas mass flow under several, kgh^-1；Air under average excess air coefficient is imported and exported for air preheater air side Mass flow, kgh^-1；The air specific heat under mean temperature, kJ (kg DEG C) are imported and exported for air preheater^-1；For Air preheater imports and exports the flue gas specific heat under mean temperature, kJ (kg DEG C)^-1；Δη_kyBefore and after changing for feed temperature The difference of air preheater fume side heat exchange efficiency, i.e. Δ η_ky=η_ky1-η_ky, η_ky1Air preheater after changing for feed temperature Fume side heat exchange efficiency, η_kyAir preheater fume side heat exchange efficiency before changing for feed temperature；t₀For air preheater into Mouth cold wind temperature, DEG C；

The air quality flow for flowing through air preheater is：

Section 4 offset component in formula (3), i.e. air preheater air mass flow can be obtained by formula (1) and formula (9) Variation causes air preheater to export hot air temperature variable quantity：

In formula：Cause air preheater to export hot air temperature for the variation of air preheater air mass flow to become Change amount, DEG C；t_fwFor boiler feed temperature, DEG C；t_rkHot blast temperature is exported for air preheater, is first to estimate post-equalization in calculating, ℃；Δt_fwFor the variable quantity of feed temperature, DEG C；θ′_kyFor air preheater import smoke temperature, DEG C；η_kyFor air preheater fume side Heat exchange efficiency；For system errors；The cigarette under average excess air coefficient is imported and exported for air preheater fume side Gas mass flow, kgh^-1；Air quality flow under average excess air coefficient is imported and exported for air preheater air side, kg·h^-1；The air specific heat under mean temperature, kJ (kg DEG C) are imported and exported for air preheater^-1；For air preheater Import and export the flue gas specific heat under mean temperature, kJ (kg DEG C)^-1；To cause air preheater for feed temperature variation The changing value of air mass flow, kgh^-1；To consider the correction factor of unburned carbon loss For Air preheater air side is averaged excess air coefficient；V⁰For theoretical air requirement, m³·kg^-1；B is boiler fired coal consumption, kg·h^-1；Δ B is the variable quantity of fuel quantity, kgh^-1；t₀For air preheater import cold wind temperature, i.e. environment cold wind temperature, ℃；

Air preheater after variation exports hot air temperature：

(c) the calculating link of economizer exit water temperature after feed temperature changes：

In formula：t_smcFor economizer exit water temperature, DEG C；For system errors；η_smIt exchanges heat and imitates for economizer fume side Rate；θ′_smFor economizer input gas temperature, DEG C；q_m(gs)For economizer feed-water quality flow, kgh^-1；It is passed in and out for economizer Water supply specific heat under saliva mean temperature, kJ (kg DEG C)^-1；Average excess air coefficient is imported and exported for economizer fume side Under flue gas mass flow, kgh^-1；The flue gas specific heat under average flue-gas temperature, kJ (kg are imported and exported for economizer ℃)^-1；tf_wFor boiler feed temperature, DEG C.

Wherein, the fume side heat exchange efficiency of economizer is：

Wherein

It is theoretical according to differential deviation, boiler feed temperature variation is obtained by formula (10) and causes economizer exit water temperature variable quantity For：

Wherein, the 1st offset component in formula (14) can be obtained by formula (12), i.e. feed temperature variation directly causes Economizer exit water temperature variable quantity is：

2nd offset component in formula (14) can be obtained by formula (12) and formula (16), i.e. feed temperature variation causes Economizer exhaust gas volumn changes, and causes the economizer exit water temperature variable quantity to be：

In formula：Cause economizer exhaust gas volumn to change for feed temperature variation, causes economizer exit water The variable quantity of temperature, DEG C；To pass through the average flue gas volume of economizer, m³·kg^-1；To pass through the mean temperature of economizer Under smoke density, kgm^-3；t_smcFor economizer exit water temperature, DEG C；Δt_fwFor the variable quantity of feed temperature, DEG C；For Flue gas mass flow under the average excess air coefficient of economizer fume side inlet and outlet, kgh^-1；η_smIt is changed for economizer fume side The thermal efficiency；The flue gas specific heat under average flue-gas temperature, kJ (kg DEG C) are imported and exported for economizer^-1；q_m(gs)It is given for economizer Water quality flow, kgh^-1；Water supply specific heat under water mean temperature, kJ (kg DEG C) are imported and exported for economizer^-1；For system Errors；θ′_smFor economizer input gas temperature, DEG C；Δ B is the variable quantity of fuel quantity, kgh^-1；To consider machinery The correction factor of incomplete combustion loss

In formula：Δθ′_smFor economizer entrance flue gas temperature variable quantity, DEG C；On the basis of economizer entrance flue gas temperature, ℃；On the basis of furnace outlet gas temperature, DEG C；Change rear hearth for feed temperature and exports smoke temperature, DEG C, after feed temperature variation Furnace outlet gas temperature is first to estimate post-equalization in calculating, t_dzrFor low-temperature reheater inlet steam temperature, DEG C；

Method is calculated specified in calculation basis China boiler controller system thermodynamic computing standard of furnace outlet gas temperature, i.e., Introduce 1973 editions boiler controller system thermodynamic computing standard methods of the former Soviet Union of version

In formula：Change rear hearth for feed temperature and exports smoke temperature, DEG C；T_aFor theoretical temperature combustion, DEG C, T_a=Q_ar.net (1-(q₃+q₆)/(100-q₄))；σ_oIt grows rigorously constant for bohr, σ_o=5.67 × 10^-11, kW (m²·K⁴)^-1；a₁It is black for burner hearth Degree；φ is water-cooling wall thermal effective coefficient；F₁For water-cooling wall heat exchange area, m²；q₃For the imperfect combustion heat loss of gas, the value compared with It is small, it can use 0；q₆For heat loss due to sensible heat in slag, the value is smaller, can use 0；For system errors；B is boiler fired coal consumption, Post-equalization, kgh are first estimated in calculating^-1；Mean heat capacity for water cooling from furnace outlet gas temperature to theoretical temperature combustion, kJ·(kg·℃)^-1；To consider the correction factor of unburned carbon loss；M repaiies for flame central position Positive coefficient, M=A-B (X_b+ Δ x), X_bFor burner arrangement height and furnace height ratio；Δ x is that flame peak temperature is opposite Position correction value, for burner front and back wall cross collocation, Δ x=0.05, for Terms of Corner Tangential Combustion, Δ x=0；It is right In bituminous coal and lignite, A=0.59, B=0.5, for anthracite and meager coal, A=0.56, B=0.5；

3rd offset component in formula (14) can be obtained by formula (12) and formula (18), i.e. feed temperature variation causes Economizer entrance flue gas temperature changes, and then causes the economizer exit water temperature variable quantity to be：

In formula：Cause economizer entrance flue gas temperature to change for feed temperature variation, and then causes province's coal Device exit water temperature variable quantity, DEG C；t_smcFor economizer exit water temperature, DEG C；Δt_fwFor the variable quantity of feed temperature, DEG C；For Flue gas mass flow under the average excess air coefficient of economizer fume side inlet and outlet, kgh^-1；η_smIt is changed for economizer fume side The thermal efficiency；The flue gas specific heat under average flue-gas temperature, kJ (kg DEG C) are imported and exported for economizer^-1；q_m(gs)For economizer Feed-water quality flow, kgh^-1；Water supply specific heat under water mean temperature, kJ (kg DEG C) are imported and exported for economizer^-1；To be System errors；θ′_smFor economizer input gas temperature, DEG C；Δθ′_smFor economizer entrance flue gas temperature variable quantity, DEG C；

4th offset component in formula (14) can be obtained by formula (12) and formula (13), i.e., changed by economizer fume side Thermal efficiency variation causes the economizer exit water temperature variable quantity to be：

Feed temperature variation after economizer exit coolant-temperature gage be：

In formula：t_smc1Economizer exit water temperature after changing for feed temperature, DEG C；Cause province for feed temperature variation The variable quantity of coal device exit water temperature degree, DEG C；On the basis of economizer exit coolant-temperature gage, DEG C；

(d) burner hearth heat Balance Calculation link：

In formula：Q_rlTo be sent into the fuel total amount of heat of burner hearth, kJh^-1；Q_wlTo enter the fuel physical sensible heat of burner hearth, kJ h^-1；Q_rkThe heat that hot-air brings burner hearth into, kJh are exported for air preheater^-1；Q_lkTo leak into the heat of burner hearth cold air carrying Amount, kJh^-1；Q_jTo bring the heat of burner hearth, kJh by the conversion of coal-grinding component mechanical energy^-1；Q_yqIt is taken out of for furnace outlet flue gas Heat, kJh^-1；Q_hzFor the heat that burner hearth flying dust and slag are taken out of, kJh^-1；Q_fFor working medium radiation absorption heat in burner hearth Amount, kJh^-1；Q_srFor burner hearth radiation loss heat, kJh^-1；For heat of the carbon particle with flake hearth-tapping of unburned burn-up, kJ·h^-1；

1) boiler furnace inputs heat

Be sent into burner hearth fuel total amount of heat be：

In formula：Q_rlTo be sent into the fuel total amount of heat of burner hearth, kJh^-1；B is boiler fired coal consumption, after first estimating in calculating Correction, kgh^-1；Q_ar.grFor coal As-received high calorific power, kJkg^-1；η_q4To consider unburned carbon loss Correction factorQ in stable operation under the same load of boiler₄Variation is smaller, can use constant；

Fuel physical sensible heat into burner hearth is：

Q_wl=Bc_p.art_r (25)

Air preheater outlet hot-air brings the heat of burner hearth into and is：

Q_rk=B β "_kyV⁰(ct)_rk (26)

Theoretical air requirement is：

Q_lk=B Δ α V⁰(ct)_lk (28)

Q_j=3.6BK_jE (29)

2) boiler furnace inputs heat

Furnace outlet flue gas takes heat out of:

In formula：Q_yqFor the heat that furnace outlet flue gas is taken out of, kJh^-1；B is boiler fired coal consumption, is first estimated in calculating Post-equalization, kgh^-1；To consider the correction factor of unburned carbon loss For theoretical flue gas enthalpy, kJ·kg^-1；V⁰For theoretical air requirement, m³·kg^-1；a_ltFor furnace outlet excess air coefficient；(cθ)_ltFor 1m³Humid air is in stove Thorax exit gas temperature θ_ltDEG C when enthalpy, kJm^-3；

Theoretical flue gas enthalpy is：

In formula：For theoretical flue gas enthalpy, kJkg^-1；For three atomic gas volumes, m³·kg^-1；For theoretical nitrogen Volume, m³·kg^-1；For theoretical water vapor volume, m³·kg^-1；Respectively 1m³Three atom gas Body, nitrogen and vapor are in flue gas temperature of hearth outlet θ_ltDEG C when enthalpy, kJm^-3；

Burner hearth flying dust and slag take sensible heat amount out of:

Working medium radiation absorption heat is in burner hearth：

Q_f=q_m(gs)(h_fl-h_smc) (33)

In formula：For heat of the carbon particle with flake hearth-tapping of unburned burn-up, kJh^-1；B is boiler fired coal consumption, meter Post-equalization, kgh are first estimated in calculation^-1；Q_ar.netFor coal net calorific value as received basis, kJkg^-1；q₄For mechanical incomplete combustion Heat loss.

System radiating loses heat：

In formula：Q_srFor burner hearth radiation loss heat, kJh^-1；S_hdsFor burner hearth cooling surface area, m²；a_cIt conducts heat for convection current Coefficient, W (m²·℃)^-1；a_fFor radiation heat transfer coefficient, W (m²·℃)^-1；a′_cFor convective heat-transfer coefficient and radiant heat transfer system The sum of number, W (m²·℃)^-1；t_hdsFor burner hearth outer surface mean temperature, DEG C；t₀For air preheater import cold wind temperature, it is Environment cold wind temperature, DEG C；Δ t=t_hds-t₀For the difference of burner hearth hull-skin temperature and ambient air temperature, DEG C, which generally makes even 10 DEG C of mean temperature difference empirical value is calculated；

It is obtained by formula (23)-formula (35)

In formula：B is boiler fired coal consumption, and post-equalization, kgh are first estimated in calculating^-1；Q_ar.gr1It is received for what is newly calculated Base high calorific power, kJkg^-1；To consider the correction factor of unburned carbon lossBoiler is stablized Q in operation₄Variation is smaller, can use constant；Q_rlTo be sent into the fuel total amount of heat of burner hearth, kJh^-1；Q_wlTo enter the fuel of burner hearth Physical sensible heat, kJh^-1；Q_rkThe heat that hot-air brings burner hearth into, kJh are exported for air preheater^-1；Q_lkIt is cold to leak into burner hearth The heat that air carries, kJh^-1；Q_jTo bring the heat of burner hearth, kJh by the conversion of coal-grinding component mechanical energy^-1；Q_yqFor burner hearth The heat that exiting flue gas is taken out of, kJh^-1；Q_hzFor the heat that burner hearth flying dust and slag are taken out of, kJh^-1；Q_fFor working medium in burner hearth Radiation absorption heat, kJh^-1；Q_srFor burner hearth radiation loss heat, kJh^-1；Q_q4For the carbon particle band flake hearth-tapping of unburned burn-up Heat, kJh^-1。

The computer software programs of the present invention are worked out according to automation control, computer processing technology, and program language is this Technology known to field technology personnel.

(a) basic parameter and operation and structural parameters input element：

Calculated examples：The following Tables 1 and 2 institute of input reference parameter and operating parameter of certain 600MW supercritical once-through boiler Show.Combustion system is quadrangle tangential circle, and fuel is lignite, and sets feed temperature changing value as -10 DEG C, and feed temperature declines 10 DEG C, i.e.,

1 input reference parameter list of table

Equivalent fuel amount (kgh^-1)	250991	Baseline air preheater flue gas specific heat (kJ (kg DEG C)^-1)	1.11
				Benchmark hot air temperature (DEG C)	325	Baseline air preheater air specific heat (kJ (kg DEG C)^-1)	1.021
Baseline air preheater import smoke temperature (DEG C)	379	Benchmark exhaust gas temperature (DEG C)	126.5
				Benchmark feed temperature (DEG C)	282	Benchmark furnace outlet gas temperature (DEG C)	1376
Air mass flow (the kgh of baseline air preheater^-1)	2206510.21	Baseline air preheater flue gas side heat exchange efficiency	0.703
				Flue gas flow (the kgh of baseline air preheater^-1)	2530526.90	Flue gas flow (the kgh of benchmark economizer^-1)	2455930.87
Benchmark economizer flue gas specific heat (kJ (kg DEG C)^-1)	1.173365	Benchmark water supply specific heat (kJ (kg DEG C)^-1)	5.4001
				Benchmark economizer exit water temperature (DEG C)	336.8	Benchmark economizer import smoke temperature (DEG C)	564
Benchmark economizer fume side heat exchange efficiency	0.645

Operation and structural parameters include：Environment cold wind temperature, slag temperature, burner hearth cooling surface area, flying dust share, clinker Share, feedwater flow, errors, coal elemental composition, heat loss of imperfect solid combustion, low-temperature reheater inlet steam temperature, Energy transformation ratio, pulverized coal preparation system unit electricity in air preheater heat transfer area, economizer heat transfer area, coal pulverizer mill processes The excess of consumption, the air leakage coefficient and furnace outlet excess air coefficient of burner hearth and pulverized coal preparation system, air preheater air side outlet Air coefficient and economizer exit water pressure；

The input of table 2 operation and structural parameters inventory

(b) the calculating link of air preheater outlet hot blast temperature after feed temperature changes

Clear for ease of what is described in logical relation below, intermediate computations formula is not elaborating.

According to shown in Fig. 2 and Fig. 3, fuel quantity, air preheater after estimation feed temperature variation export hot air temperature And furnace outlet gas temperature.Fuel quantity and air preheater after being changed first by the feed temperature of estimation export hot air temperature Boiler obtains final furnace outlet gas temperature value by iterative calculationIteration error is 0.1 DEG C, i.e. estimated value and calculated value Absolute error stops calculating when being less than 0.1 DEG C, otherwise from the new furnace outlet gas temperature of new estimation, and is calculated from newly, until Meet required precision；

Then new air preheater is calculated according to the fuel quantity after the feed temperature variation of estimation and by formula (11) Hot air temperature is exported, and is compared with advance estimate, if the two absolute error is less than 0.1 DEG C, iterates to calculate stopping, At this moment final air preheater outlet hot air temperature t is obtained_rk1.Otherwise hot-air temperature is exported from new estimation air preheater Degree, and need from the new calculating for carrying out furnace outlet gas temperature, until all coincidence loss requires；

Wherein, formula (11) form of calculation is as follows：

Formula (1)-formula (10) is to obtain the intermediate formulas of formula (11).

The form of calculation difference of formula (1)-(10) is as follows：

Formula (1) is：

Formula (2) is：

Wherein

Formula (3) is：

Formula (4) is：

Formula (5) is：

Formula (6) is：

Formula (7) is：

Formula (8) is：

Formula (9) is：

Formula (10) is：

(c) the calculating link of economizer exit water temperature after feed temperature changes

According to shown in Fig. 2 and Fig. 3, according to after the feed temperature variation of estimation fuel quantity and the furnace outlet that is calculated Smoke temperatureThe economizer exit water temperature t after feed temperature variation is calculated by formula (22)_smc1；

Wherein, formula (22) form of calculation is as follows：

Formula (12)-formula (21) is to obtain the intermediate formulas of formula (22).

The form of calculation difference of formula (12)-(21) is as follows：

Formula (12) is：

Formula (13) is：

Wherein

Formula (14) is：

Formula (15) is：

Formula (16) is：

Formula (17) is：

Formula (18) is：

Formula (19) is：

Formula (20) is：

Formula (21) is：

(d) burner hearth heat Balance Calculation link：

This link is substantially carried out the calculation and check of fuel quantity.The main thought for checking fuel quantity is using estimation to water temperature The fuel quantity spent after variation and the furnace outlet gas temperature being calculated by b linksHot air temperature is exported with air preheater t_rk1, the economizer exit water temperature t that is calculated of d links_smc1It generates heat from the new high position for calculating fuel in conjunction with burner hearth heat balance theory Amount, if the high calorific power for the fuel being calculated and the absolute error being previously entered between operating parameter given value are less than 500kJ·kg^-1, that is, think that calculating meets required precision, otherwise should return to c links from the fuel after the variation of new estimation feed temperature Amount, air preheater outlet hot air temperature and furnace outlet gas temperature, are calculated from newly, are until all meeting required precision Only；

In conjunction with Fig. 2 and Fig. 3, the calculating of fuel high calorific power can be carried out according to the formula (36) that burner hearth thermal balance obtains, Formula (36) is as follows：

Formula (23)-formula (35) is to obtain the intermediate formulas of formula (36)；

The form of calculation difference of formula (23)-formula (35) is as follows：

Formula (23) is：

Formula (24) is：

Formula (25) is：

Q_wl=Bc_p.art_r (25)

Formula (26) is：

Q_rk=B β "_kyV⁰(ct)_rk (26)

Formula (27) is：

Formula (28) is：

Q_lk=B Δ α V⁰(ct)_lk (28)

Formula (29) is：

Q_j=3.6BK_jE (29)

Formula (30) is：

Formula (31) is：

Formula (32) is：

Formula (33) is：

Q_f=q_m(gs)(h_fl-h_smc) (33)

Formula (34) is：

Formula (35) is：

Q_sr=S_hds(a_c+a_f)(t_hds-t₀)=S_hdsa_c′Δt (35)

Changing value according to calculating step and given feed temperature described in a links-d links as aboveAnd it is calculated in conjunction with the basic parameter and operation and structural parameters that a links are inputted, result of calculation As shown in table 3：

3 feed temperature of table declines 10 DEG C of result of calculation (result retains 3 effective digitals)

By table 3 as it can be seen that a kind of feed temperature given by the present invention changes the correction to supercritical once-through boiler fuel quantity Method can be very good the variation of quantitative response feed temperature to fuel in the case of boiler load and certain main steam condition The quantitative effect of amount and part operating parameter.Therefore, a kind of feed temperature variation of the present invention is to supercritical once-through boiler fuel quantity Bearing calibration preferably can quantitatively indicate the adjustment of feed temperature variation after-burning doses even coal-water ratio.

Claims

1. a kind of feed temperature changes the bearing calibration to supercritical once-through boiler fuel quantity, characterized in that the content that it includes Have：

(a) basic parameter and operation and structural parameters input：

The link is mainly met by the input of basic parameter and the input of operating parameter instantly corresponding after feed temperature changes The calculating of operating parameter, since basic parameter and operating parameter are to determine the important parameter of fuel quantity variation, and load is different, base Quasi- parameter and operating parameter differ greatly, and therefore, the basic parameter and operating parameter of input must be the operations of load instantly Parameter also can use design parameter under different load and be inputted as basic parameter in practical calculating；The basic parameter includes： Fuel quantity, air preheater import smoke temperature, feed temperature, the air mass flow for flowing through air preheater, flows through sky at hot air temperature Flue gas flow, air preheater flue gas specific heat, air preheater air specific heat, exhaust gas temperature, the furnace outlet cigarette of air preheater Temperature, saves coal at air preheater fume side heat exchange efficiency, the flue gas flow for flowing through economizer, economizer flue gas specific heat, water supply specific heat Device exit water temperature, economizer import smoke temperature, economizer fume side heat exchange efficiency；The operation and structural parameters include：Environment is cold Air temperature, slag temperature, burner hearth cooling surface area, flying dust share, clinker share, feedwater flow, errors, coal elemental composition, Heat loss of imperfect solid combustion, low-temperature reheater inlet steam temperature, air preheater heat transfer area, economizer heat-transfer area Energy transformation ratio, pulverized coal preparation system unit power consumption, burner hearth air leakage coefficient, pulverized coal preparation system leak out and are in product, coal pulverizer mill processes Number, furnace outlet excess air coefficient, the excess air coefficient of air preheater air side outlet and economizer exit water pressure；

Feed temperature change causes the fuel quantity of boiler to change, constant in furnace outlet excess air coefficient, will The air mass flow and flue gas flow for causing air preheater change, and are obtained by air preheater energy-balance equation：

In formula：t_rkHot blast temperature is exported for air preheater, is first to estimate post-equalization in calculating, DEG C；η_kyFor air preheater cigarette Gas side heat exchange efficiency；For system errors；It is imported and exported under average excess air coefficient for air preheater fume side Flue gas mass flow, kgh^-1；Air quality under average excess air coefficient is imported and exported for air preheater air side Flow, kgh^-1；θ′_kyFor air preheater import smoke temperature, DEG C；The air under mean temperature is imported and exported for air preheater Specific heat, kJ (kg DEG C)^-1；The flue gas specific heat under mean temperature, kJ (kg DEG C) are imported and exported for air preheater^-1；t₀ For air preheater import cold wind temperature, i.e. environment cold wind temperature, DEG C；

Wherein

In formula：η_kyFor air preheater fume side heat exchange efficiency；K_kyFor air preheater heat transfer coefficient, W (m²·℃)^-1；A_ky For air preheater heat transfer area, m²；The flue gas under average excess air coefficient is imported and exported for air preheater fume side Mass flow, kgh^-1；Air quality flow under average excess air coefficient is imported and exported for air preheater air side, kg·h^-1；θ′_kyFor air preheater import smoke temperature, DEG C；The air specific heat under mean temperature is imported and exported for air preheater, kJ·(kg·℃)^-1；The flue gas specific heat under mean temperature, kJ (kg DEG C) are imported and exported for air preheater^-1；t₀For sky Air preheater import cold wind temperature, i.e. environment cold wind temperature, DEG C；θ_pyFor exhaust gas temperature, DEG C；

In formula：Cause the variable quantity of air preheater outlet hot blast temperature for feed temperature variation, DEG C；t_fwIt is given for boiler Coolant-temperature gage, DEG C；t_rkHot blast temperature is exported for air preheater, is first to estimate post-equalization in calculating, DEG C；η_kyFor air preheater Fume side heat exchange efficiency；The flue gas mass flow under average excess air coefficient is imported and exported for air preheater fume side, kg·h^-1；Air quality flow under average excess air coefficient, kgh are imported and exported for air preheater air side^-1；Δ t_fwFor the variable quantity of feed temperature, DEG C, here,t_fw1For the feed temperature after variation,On the basis of give water temperature Degree；

In formula：The flue gas mass flow under average excess air coefficient, kgh are imported and exported for air preheater fume side^-1；To pass through the average flue gas volume of air preheater, m³·kg^-1；To pass through the flue gas under air preheater mean temperature Density, kg (m³)^-1；B is boiler fired coal consumption, is first to estimate post-equalization in calculating, kgh^-1；q₄For mechanical not exclusively combustion Heat loss；

1st offset component in formula (3) is obtained by formula (1) and formula (4), i.e. air preheater flue gas flow variation causes Air preheater exports hot air temperature variable quantity：

In formula：Air preheater is caused to export hot air temperature variable quantity for the variation of air preheater exhaust gas volumn, ℃；To pass through the average flue gas volume of air preheater, m³·kg^-1；For by under air preheater mean temperature Smoke density, kg (m³)^-1；FootmarkTo take the relevant parameter of a reference value, t in calculating_rkHot wind is exported for air preheater Temperature is first to estimate post-equalization in calculating, DEG C；η_kyFor air preheater fume side heat exchange efficiency；For system errors；The flue gas mass flow under average excess air coefficient, kgh are imported and exported for air preheater fume side^-1；For sky Air quality flow under the average excess air coefficient of air preheater air side inlet and outlet, kgh^-1；θ′_kyFor air preheater into Mouth smoke temperature, DEG C；The air specific heat under mean temperature, kJ (kg DEG C) are imported and exported for air preheater^-1；It is pre- for air Flue gas specific heat under hot device inlet and outlet mean temperature, kJ (kg DEG C)^-1；t₀For air preheater import cold wind temperature, DEG C；To consider the correction factor of unburned carbon loss；Δt_fwFor the variable quantity of feed temperature, DEG C；Δ B is The variable quantity of fuel quantity caused by feed temperature, kgh^-1, i.e. Δ B=B₁-B⁰, wherein B₁Fuel after changing for feed temperature Amount, is first to estimate post-equalization in calculating, B⁰On the basis of fuel quantity；t₀For air preheater import cold wind temperature, DEG C；

The variable quantity of air preheater import smoke temperature is：

In formula：Δθ′_kyCause the variable quantity of air preheater import smoke temperature for feed temperature variation, DEG C；θ′_sm1For feed temperature Economizer import smoke temperature after variation, DEG C；t_fw1For the feed temperature after variation, DEG C；η_sm1Province's coal after changing for feed temperature Device fume side heat exchange efficiency；For air preheater benchmark entrance flue gas temperature, DEG C；

2nd offset component in formula (3) is obtained by formula (1) and formula (6), i.e. air preheater entrance flue gas temperature changes Cause air preheater outlet hot air temperature variable quantity be：

In formula：Cause air preheater to export hot air temperature for the variation of air preheater entrance flue gas temperature to become Change amount, DEG C；t_fwFor boiler feed temperature, DEG C；t_rkHot blast temperature is exported for air preheater, is first to estimate post-equalization in calculating, ℃；θ′_kyFor air preheater import smoke temperature, DEG C；η_kyFor air preheater fume side heat exchange efficiency；For system errors；The flue gas mass flow under average excess air coefficient, kgh are imported and exported for air preheater fume side^-1；For sky Air quality flow under the average excess air coefficient of air preheater air side inlet and outlet, kgh^-1；It is passed in and out for air preheater Air specific heat under mouth mean temperature, kJ (kg DEG C)^-1；The flue gas ratio under mean temperature is imported and exported for air preheater Heat, kJ (kg DEG C)^-1；Δθ′_kyCause the variable quantity of air preheater import smoke temperature for feed temperature variation, DEG C；

3rd offset component in formula (3), the variation of air preheater fume side heat exchange efficiency are obtained by formula (1) and formula (2) Cause air preheater outlet hot air temperature variable quantity be：

In formula：Air preheater is caused to export hot air temperature for the variation of air preheater fume side heat exchange efficiency Variable quantity, DEG C；t_fwFor boiler feed temperature, DEG C；t_rkHot blast temperature is exported for air preheater, is school after first estimation in calculating Just, DEG C；Δt_fwFor the variable quantity of feed temperature, DEG C；θ′_kyFor air preheater import smoke temperature, DEG C；η_kyFor air preheater cigarette Gas side heat exchange efficiency；For system errors；It is imported and exported under average excess air coefficient for air preheater fume side Flue gas mass flow, kgh^-1；Air quality under average excess air coefficient is imported and exported for air preheater air side Flow, kgh^-1；The air specific heat under mean temperature, kJ (kg DEG C) are imported and exported for air preheater^-1；For air Preheater imports and exports the flue gas specific heat under mean temperature, kJ (kg DEG C)^-1；Δη_kyTo change front and back air for feed temperature The difference of preheater flue gas side heat exchange efficiency, i.e. Δ η_ky=η_ky1-η_ky, η_ky1Air preheater flue gas after changing for feed temperature Side heat exchange efficiency, η_kyAir preheater fume side heat exchange efficiency before changing for feed temperature；t₀It is cold for air preheater import Air temperature, DEG C；

The air quality flow for flowing through air preheater is：

In formula：q_m(kq)To flow through the air quality flow of air preheater, kg/s；For air preheater air side averagely mistake Measure air coefficient；V⁰For theoretical air requirement, m³·kg^-1；B is boiler fired coal consumption, is first to estimate post-equalization in calculating, kg h^-1；q₄For heat loss due to combustibles in refuse；

4th offset component in formula (3) is obtained by formula (1) and formula (9), i.e. air preheater air mass flow variation causes Air preheater exports hot air temperature variable quantity：

In formula：Air preheater is caused to export hot air temperature variation for the variation of air preheater air mass flow Amount, DEG C；t_fwFor boiler feed temperature, DEG C；t_rkHot blast temperature is exported for air preheater, is first to estimate post-equalization in calculating, ℃；Δt_fwFor the variable quantity of feed temperature, DEG C；θ′_kyFor air preheater import smoke temperature, DEG C；η_kyFor air preheater fume side Heat exchange efficiency；For system errors；The cigarette under average excess air coefficient is imported and exported for air preheater fume side Gas mass flow, kgh^-1；Air mass flow under average excess air coefficient is imported and exported for air preheater air side Amount, kgh^-1；The air specific heat under mean temperature, kJ (kg DEG C) are imported and exported for air preheater^-1；It is pre- for air Flue gas specific heat under hot device inlet and outlet mean temperature, kJ (kg DEG C)^-1；To cause air pre- for feed temperature variation The changing value of hot device air mass flow, kgh^-1；To consider the correction factor of unburned carbon loss； It is averaged excess air coefficient for air preheater air side；V⁰For theoretical air requirement, m³·kg^-1；B is boiler fired coal consumption, kg·h^-1；Δ B is the variable quantity of fuel quantity, kgh^-1；t₀For air preheater import cold wind temperature, i.e. environment cold wind temperature, ℃；

Air preheater after variation exports hot air temperature：

In formula：t_rk1Air preheater after changing for feed temperature exports hot air temperature, DEG C；On the basis of air preheater Outlet air temperature, DEG C；Cause the variable quantity of air preheater outlet hot air temperature for feed temperature variation, DEG C.

After feed temperature variation, economizer heat-transfer character is caused to change, economizer exit water temperature is caused to change, economizer energy is flat Weighing apparatus equation be：

In formula：t_smcFor economizer exit water temperature, DEG C；For system errors；η_smFor economizer fume side heat exchange efficiency；θ′_sm For economizer input gas temperature, DEG C；q_m(gs)For economizer feed-water quality flow, kgh^-1；It is imported and exported for economizer horizontal Water supply specific heat at equal temperature, kJ (kg DEG C)^-1；The cigarette under average excess air coefficient is imported and exported for economizer fume side Gas mass flow, kgh^-1；The flue gas specific heat under average flue-gas temperature, kJ (kg DEG C) are imported and exported for economizer^-1；t_fw For boiler feed temperature, DEG C；

Wherein, the fume side heat exchange efficiency of economizer is：

Wherein

In formula：η_smFor economizer fume side heat exchange efficiency；θ′_smFor economizer input gas temperature, DEG C；K_smIt conducts heat for economizer Coefficient, kW (m²·℃)^-1；A_smFor economizer heat transfer area, m²；q_m(gs)For economizer feed-water quality flow, kgh^-1； Water supply specific heat under water mean temperature, kJ (kg DEG C) are imported and exported for economizer^-1；It is flat for economizer fume side inlet and outlet Flue gas mass flow under equal excess air coefficient, kgh^-1；The flue gas ratio under average flue-gas temperature is imported and exported for economizer Heat, kJ (kg DEG C)^-1；θ′_kyFor air preheater import smoke temperature, DEG C；t_fwFor boiler feed temperature, DEG C；

In formula：Cause the variable quantity of economizer exit coolant-temperature gage for feed temperature variation, DEG C；t_smcFor economizer exit Water temperature, DEG C；Δt_fwFor the variable quantity of feed temperature, DEG C；It is imported and exported under average excess air coefficient for economizer fume side Flue gas mass flow, kgh^-1；η_smFor economizer fume side heat exchange efficiency；θ′_smFor economizer input gas temperature, DEG C；t_fw For boiler feed temperature, DEG C；

Wherein, the 1st offset component in formula (14) is obtained by formula (12), i.e. feed temperature variation directly causes economizer Exit water temperature variable quantity is：

In formula：Directly cause the variable quantity of economizer exit coolant-temperature gage for feed temperature variation, DEG C；t_smcFor economizer Exit water temperature, DEG C；Δt_fwFor the variable quantity of feed temperature, DEG C；Average excess air system is imported and exported for economizer fume side Flue gas mass flow under several, kgh^-1；η_smFor economizer fume side heat exchange efficiency；Average flue gas is imported and exported for economizer At a temperature of flue gas specific heat, kJ (kg DEG C)^-1；q_m(gs)For economizer feed-water quality flow, kgh^-1；For economizer into Export water supply specific heat under water mean temperature, kJ (kg DEG C)^-1；For system errors；

In formula：To pass through the average flue gas volume of economizer, m³·kg^-1；For by under the mean temperature of economizer Smoke density, kgm^-3；B is boiler fired coal consumption, is first to estimate post-equalization in calculating, kgh^-1；q₄It is mechanical incomplete Combustion heat loss；

2nd offset component in formula (14) is obtained by formula (12) and formula (16), i.e. feed temperature variation leads to economizer Exhaust gas volumn changes, and causes the economizer exit water temperature variable quantity to be：

In formula：Cause economizer exhaust gas volumn to change for feed temperature variation, causes the change of economizer exit water temperature Change amount, DEG C；To pass through the average flue gas volume of economizer, m³·kg^-1；To pass through the cigarette under the mean temperature of economizer Air tightness, kgm^-3；t_smcFor economizer exit water temperature, DEG C；Δt_fwFor the variable quantity of feed temperature, DEG C；For economizer Flue gas mass flow under the average excess air coefficient of fume side inlet and outlet, kgh^-1；η_smIt exchanges heat and imitates for economizer fume side Rate；The flue gas specific heat under average flue-gas temperature, kJ (kg DEG C) are imported and exported for economizer^-1；q_m(gs)It is economizer to water quality Measure flow, kgh^-1；Water supply specific heat under water mean temperature, kJ (kg DEG C) are imported and exported for economizer^-1；It is protected for system Hot coefficient；θ′_smFor economizer input gas temperature, DEG C；Δ B is the variable quantity of fuel quantity, kgh^-1；To consider The correction factor of unburned carbon loss；

After feed temperature variation, the fume side heat exchange efficiency from furnace outlet to economizer entrance is defined, and be approximately considered from stove The fume side heat exchange efficiency that thorax exports to economizer entrance is constant, obtains economizer entrance flue gas temperature variable quantity and is：

In formula：Δθ′_smFor economizer entrance flue gas temperature variable quantity, DEG C；On the basis of economizer entrance flue gas temperature, DEG C；On the basis of furnace outlet gas temperature, DEG C；Change rear hearth for feed temperature and exports smoke temperature, DEG C；Stove after feed temperature variation It is first to estimate post-equalization that thorax, which exports during smoke temperature calculates, t_dzrFor low-temperature reheater inlet steam temperature, DEG C；

In formula：Change rear hearth for feed temperature and exports smoke temperature, DEG C；T_aFor theoretical temperature combustion, DEG C, T_a=Q_ar.net(1-(q₃+ q₆)/(100-q₄))；σ_oIt grows rigorously constant for bohr, σ_o=5.67 × 10^-11, kW (m²·K⁴)^-1；a₁For furnace emissivity；φ is water Cold wall thermal effective coefficient；F₁For water-cooling wall heat exchange area, m²；q₃For the imperfect combustion heat loss of gas, the value is smaller, can use 0； q₆For heat loss due to sensible heat in slag, the value is smaller, can use 0；For system errors；B is boiler fired coal consumption, in calculating first Estimate post-equalization, kgh^-1；Mean heat capacity for water cooling from furnace outlet gas temperature to theoretical temperature combustion, kJ (kg ℃)^-1；To consider the correction factor of unburned carbon loss；M is flame central position correction factor, M= A-B(X_b+ Δ x), X_bFor burner arrangement height and furnace height ratio；Δ x is flame peak temperature relative position amendment Value, for burner front and back wall cross collocation, Δ x=0.05, for Terms of Corner Tangential Combustion, Δ x=0；For bituminous coal and Lignite, A=0.59, B=0.5, for anthracite and meager coal, A=0.56, B=0.5,

3rd offset component in formula (14) is obtained by formula (12) and formula (18), i.e. feed temperature variation leads to economizer Entrance flue gas temperature changes, and then causes the economizer exit water temperature variable quantity to be：

In formula：Cause economizer entrance flue gas temperature to change for feed temperature variation, and then economizer is caused to go out Saliva temperature variable quantity, DEG C；t_smcFor economizer exit water temperature, DEG C；Δt_fwFor the variable quantity of feed temperature, DEG C；For economizer Flue gas mass flow under the average excess air coefficient of fume side inlet and outlet, kgh^-1；η_smIt exchanges heat and imitates for economizer fume side Rate；The flue gas specific heat under average flue-gas temperature, kJ (kg DEG C) are imported and exported for economizer^-1；q_m(gs)It is economizer to water quality Measure flow, kgh^-1；Water supply specific heat under water mean temperature, kJ (kg DEG C) are imported and exported for economizer^-1；It is protected for system Hot coefficient；θ′_smFor economizer input gas temperature, DEG C；Δθ′_smFor economizer entrance flue gas temperature variable quantity, DEG C；

4th offset component in formula (14) is obtained by formula (12) and formula (13), i.e., by economizer fume side heat exchange efficiency Variation causes the economizer exit water temperature variable quantity to be：

In formula：To cause economizer exit water temperature variable quantity by the variation of economizer fume side heat exchange efficiency, DEG C；The flue gas mass flow under average excess air coefficient, kgh are imported and exported for economizer fume side^-1；For economizer into Flue gas specific heat under the average flue-gas temperature in outlet, kJ (kg DEG C)^-1；q_m(gs)For economizer feed-water quality flow, kgh^-1；Water supply specific heat under water mean temperature, kJ (kg DEG C) are imported and exported for economizer^-1；For system errors；θ′_smTo save Coal device input gas temperature, DEG C；t_fwFor boiler feed temperature, DEG C；Δη_smChange front and back economizer fume side for feed temperature to change The difference of the thermal efficiency, i.e.,η_sm1Economizer fume side heat exchange efficiency after changing for feed temperature,For base Quasi- economizer fume side heat exchange efficiency；

Feed temperature variation after economizer exit coolant-temperature gage be：

In formula：t_smc1Economizer exit water temperature after changing for feed temperature, DEG C；Cause economizer for feed temperature variation The variable quantity of exit water temperature degree, DEG C；On the basis of economizer exit coolant-temperature gage, DEG C；

(d) burner hearth thermal balance：

Boiler furnace is an opening therrmodynamic system, and under steady working condition, after feed temperature variation, boiler furnace thermal balance relationship is：

In formula：Q_rlTo be sent into the fuel total amount of heat of burner hearth, kJh^-1；Q_wlTo enter the fuel physical sensible heat of burner hearth, kJh^-1； Q_rkThe heat that hot-air brings burner hearth into, kJh are exported for air preheater^-1；Q_lkTo leak into the heat of burner hearth cold air carrying, kJ·h^-1；Q_jTo bring the heat of burner hearth, kJh by the conversion of coal-grinding component mechanical energy^-1；Q_yqIt is taken out of for furnace outlet flue gas Heat, kJh^-1；Q_hzFor the heat that burner hearth flying dust and slag are taken out of, kJh^-1；Q_fFor working medium radiation absorption heat in burner hearth, kJ·h^-1；Q_srFor burner hearth radiation loss heat, kJh^-1；For heat of the carbon particle with flake hearth-tapping of unburned burn-up, kJh^-1；

1) boiler furnace inputs heat

Be sent into burner hearth fuel total amount of heat be：

In formula：Q_rlTo be sent into the fuel total amount of heat of burner hearth, kJh^-1；B is boiler fired coal consumption, and post-equalization is first estimated in calculating, kg·h^-1；Q_ar.grFor coal As-received high calorific power, kJkg^-1；To consider the amendment system of unburned carbon loss NumberQ in stable operation under the same load of boiler₄Variation is smaller, can use constant；

Fuel physical sensible heat into burner hearth is：

Q_wl=Bc_p.art_r (25)

In formula：Q_wlTo enter the fuel physical sensible heat of burner hearth, kJh^-1；B is boiler fired coal consumption, school after first estimating in calculating Just, kgh^-1；c_p.arFor coal As-received specific heat at constant pressure, kJ (kg DEG C)^-1；t_rThe temperature of coal, takes ring when to be sent into burner hearth Border temperature, DEG C；

Air preheater outlet hot-air brings the heat of burner hearth into and is：

Q_rk=B β "_kyV⁰(ct)_rk (26)

In formula：Q_rkThe heat that hot-air brings burner hearth into, kJh are exported for air preheater^-1；B is boiler fired coal consumption, is calculated It is middle first to estimate post-equalization, kgh^-1；β″_kyFor the excess air coefficient of air preheater air side outlet；V⁰For theoretical air requirement, m³·kg^-1；(ct)_rkFor 1m³Humid air is in temperature t_rkDEG C when enthalpy, kJm^-3；

Theoretical air requirement is：

In formula：V⁰For theoretical air requirement, m³·kg^-1；C_arFor As-received carbon content, %；S_arFor As-received sulfur content, %；H_arFor As-received hydrogen content, %；O_arFor As-received oxygen content, %；

Q_lk=B Δ α V⁰(ct)_lk (28)

In formula：Q_lkTo leak into the heat of burner hearth cold air carrying, kJh^-1；B is boiler fired coal consumption, school after first estimating in calculating Just, kgh^-1；Δ α be burner hearth and pulverized coal preparation system air leakage coefficient and；(ct)_lkFor every 1m³Humid air is in temperature t_lkDEG C when enthalpy, kJ·m^-3；V⁰For theoretical air requirement, m³·kg^-1；

Q_j=3.6BK_jE (29)

In formula：Q_jTo bring the heat of burner hearth, kJh by the conversion of coal-grinding component mechanical energy^-1；B is boiler fired coal consumption, is calculated It is middle first to estimate post-equalization, kgh^-1；K_jFor energy transformation ratio in coal pulverizer mill processes；E is pulverized coal preparation system unit power consumption, is stablized Definite value, kWh t are essentially in operation^-1；

2) boiler furnace inputs heat

Furnace outlet flue gas takes heat out of：

In formula：Q_yqFor the heat that furnace outlet flue gas is taken out of, kJh^-1；B is boiler fired coal consumption, school after first estimating in calculating Just, kgh^-1；To consider the correction factor of unburned carbon loss；For theoretical flue gas enthalpy, kJkg^-1；V⁰For theoretical air requirement, m³·kg^-1；a_ltFor furnace outlet excess air coefficient；(cθ)_ltFor 1m³Humid air is in furnace outlet Flue-gas temperature θ_ltDEG C when enthalpy, kJm^-3；

Theoretical flue gas enthalpy is：

In formula：For theoretical flue gas enthalpy, kJkg^-1；For three atomic gas volumes, m³·kg^-1；For theoretical nitrogen volume, m³·kg^-1；For theoretical water vapor volume, m³·kg^-1；Respectively 1m³Three atomic gas, nitrogen Gas and vapor are in flue gas temperature of hearth outlet θ_ltDEG C when enthalpy, kJm^-3；

Burner hearth flying dust and slag take sensible heat amount out of:

In formula：Q_hzFor the heat that burner hearth flying dust and slag are taken out of, kJh^-1；B is boiler fired coal consumption, school after first estimating in calculating Just, kgh^-1；A_arFor coal As-received ash content, %；a_fhFor flying dust share；(cθ)_ltIn temperature it is θ for 1kg flying dusts_ltWhen enthalpy, kJ·kg^-1；a_lzFor clinker share；(cθ)_lzIn temperature it is θ for 1kg slags_lzWhen enthalpy, kJkg^-1；Q_ar.netFor coal As-received Low heat valve, kJkg^-1；q₄For heat loss due to combustibles in refuse；

Working medium radiation absorption heat is in burner hearth：

Q_f=q_m(gs)(h_fl-h_smc) (33)

In formula：Q_fFor working medium radiation absorption heat, kJh in burner hearth^-1；q_m(gs)For economizer feed-water quality flow, kgh^-1； h_flFor working medium enthalpy in direct current cooker separator, intermediate point enthalpy is arrange parameter in operation, kJkg^-1；h_smcFor economizer Go out saliva enthalpy, is determined by feed temperature and feed pressure, kJkg^-1；

In formula：For heat of the carbon particle with flake hearth-tapping of unburned burn-up, kJh^-1；B is boiler fired coal consumption, in calculating first Estimate post-equalization, kgh^-1；Q_ar.netFor coal net calorific value as received basis, kJkg^-1；q₄For heat loss due to combustibles in refuse；

System radiating loses heat：

In formula：Q_srFor burner hearth radiation loss heat, kJh^-1；S_hdsFor burner hearth cooling surface area, m²；a_cFor convective heat-transfer coefficient, W·(m²·℃)^-1；a_fFor radiation heat transfer coefficient, W (m²·℃)^-1；a′_cFor convective heat-transfer coefficient and radiation heat transfer coefficient it With W (m²·℃)^-1；t_hdsFor burner hearth outer surface mean temperature, DEG C；t₀For air preheater import cold wind temperature, i.e. environment Cold wind temperature, DEG C；Δ t=t_hds-t₀For the difference of burner hearth hull-skin temperature and ambient air temperature, DEG C, which generally makes even samming 10 DEG C of poor empirical value is calculated；

It is obtained by formula (23)-formula (35)

In formula：B is boiler fired coal consumption, and post-equalization, kgh are first estimated in calculating^-1；Q_ar.gr1For the As-received height newly calculated Position calorific value, kJkg^-1；To consider the correction factor of unburned carbon loss, q in stable operation of the boiler₄ Variation is smaller, can use constant；Q_rlTo be sent into the fuel total amount of heat of burner hearth, kJh^-1；Q_wlFuel physical to enter burner hearth is shown Heat, kJh^-1；Q_rkThe heat that hot-air brings burner hearth into, kJh are exported for air preheater^-1；Q_lkIt is taken to leak into burner hearth cold air The heat of band, kJh^-1；Q_jTo bring the heat of burner hearth, kJh by the conversion of coal-grinding component mechanical energy^-1；Q_yqFor furnace outlet cigarette The heat that gas is taken out of, kJh^-1；Q_hzFor the heat that burner hearth flying dust and slag are taken out of, kJh^-1；Q_fIt is inhaled for working medium radiation in burner hearth Receive heat, kJh^-1；Q_srFor burner hearth radiation loss heat, kJh^-1；For heat of the carbon particle with flake hearth-tapping of unburned burn-up Amount, kJh^-1。