JP6907151B2 - Combustion furnace combustion state estimation method, combustion furnace combustion control method, and combustion furnace combustion control device - Google Patents

Description

The present invention relates to a method for estimating a combustion state of a combustion furnace, a method for controlling combustion in a combustion furnace, and a combustion control device for a combustion furnace.

In combustion processes such as waste incineration plants and biomass combustion plants, high efficiency and stability are achieved while suppressing the generation of harmful substances such as carbon monoxide, nitrogen oxides, sulfur oxides, hydrogen chloride, and mercury in exhaust gas as much as possible. Operation management that can recover heat is required. However, since miscellaneous waste and biomass are used as fuel, that is, the object to be treated in these plants, the characteristics (material, shape, moisture, calorific value, etc.) of the object to be processed fluctuate greatly, and the combustion state is likely to fluctuate. Stable combustion is indispensable for stable and highly efficient plant operation. For this purpose, operational efforts such as stirring and homogenizing the object to be processed in the pit where the object to be processed is put in before combustion, and various combustion control methods for responding to fluctuations in the combustion state It is being developed.

In these plants, that is, combustion furnaces using waste and biomass as objects to be treated, generally, the temperature distribution of each part in the furnace, the oxygen concentration at the outlet of the furnace, the carbon monoxide concentration and the nitrogen oxide concentration in the exhaust gas, etc. are observed. Based on the values, keep the supply of the object to be processed into the furnace, the supply of combustion air or recirculated exhaust gas into the furnace, and the temperature inside the furnace appropriately so that they do not deviate from the appropriate control range. Therefore, combustion control is performed to adjust the flow rate of the cooling water supplied into the furnace and the supply amount of denitration chemicals such as urea water or ammonia supplied into the furnace to reduce nitrogen oxides. ing. The concept of "combustion furnace" also includes "incinerator".

However, since these combustion controls are generally configured as feedback controls based on the observed values observed as a result of the combustion of the object to be processed, they are the root cause of combustion fluctuations in the combustion furnace. Information on changes in the supply and physical properties of treated waste and biomass is not normally used.

This is to measure the supply amount and physical properties of waste or biomass, that is, the amount of water, calorific value, and chemical composition, in real time and with high accuracy before the object to be processed is put into the combustion furnace. Due to the lack of a possible measurement method or device. Therefore, if the supply amount or physical properties of the waste or bio-mass to be treated change significantly, the combustion control does not function properly, and as a result, the temperature distribution of each part in the furnace, the oxygen concentration at the furnace outlet, and the exhaust gas are exhausted. There is a problem that the carbon monoxide concentration and the nitrogen oxide concentration in the medium may deviate from the control range.

To solve these problems, it is considered to utilize the information obtained by simulating the combustion state inside the combustion furnace by thermo-fluid analysis, that is, numerical simulation.

For example, in Patent Document 1, in the combustion control method of a stoker type incinerator, various combustion patterns are defined by combining each input condition value with each of the amount of waste, the amount of air, and the moving speed as input conditions, and in each combustion pattern. The concentration and temperature distribution of the combustion gas components of the incinerator are measured, and the thermo-fluid analysis in the incinerator is performed based on the measured concentration and temperature distribution. Data is obtained, and the thermo-fluid analysis result data for each combustion pattern is input to the control device as a database in advance, and the input conditions are controlled while the dust supply device, stoker, and damper device are controlled by the control device using the process data as a control index. The flow state of the combustion gas flow in the value combustion pattern is obtained from the database as thermo-fluid analysis result data, and the combustion pattern with the thermo-fluid analysis result data that makes the flow state of the combustion gas flow better than the current one is obtained from the database. , The combustion control method of the incinerator using the thermo-fluid analysis, which is characterized in that the dust supply device, the stoker, and the damper device are controlled by the control device so as to obtain the obtained combustion pattern, is described.

Further, in Patent Document 2, in the control device of a plant having a waste incinerator, the state of the incinerator is estimated by calculating the drying of waste, the flow of gas, and the reaction heat transfer by using a simulation model expressing the incinerator process. Means to perform, means to compare the estimated state with the state based on the measured value, and correct the parameters of the simulation model so that the difference is reduced, the state is estimated again by the modified simulation model, and the state is set in advance. A control device for a waste incinerator plant is described, which comprises means for determining the amount of operation so that the estimated state approaches the set state by comparison.

Japanese Unexamined Patent Publication No. 7-4628 Japanese Patent Application Laid-Open No. 2000-097422

In the combustion control method or control device described in these prior patent documents, the combustion inside the combustion control method or control device is based on the process data obtained in the actual combustion furnace, that is, the information of the observed values such as the temperature and the gas composition. The concept of estimating the combustion state inside the combustion furnace is used by executing a numerical simulation that precisely simulates the state.

By applying this concept, it is possible to directly measure in an actual combustion furnace, such as information on the supply amount of waste and biomass, which is the underlying cause of combustion fluctuations in the combustion furnace, and fluctuations in physical properties. There is a possibility that the state quantities that cannot be estimated can be estimated by numerical simulation based on the process data obtained in the actual combustion furnace, but in the actual combustion furnace, these state quantities should be estimated accurately by such a framework. Has been difficult so far, mainly for the following three reasons.

The first reason is due to the measurement accuracy of the measuring instrument, the time lag in the measurement, the use of the measuring instrument itself, etc. in obtaining the observed values such as temperature and gas composition as the process data in the actual combustion furnace. It is inevitable that an error, that is, an observation error will occur.

The second reason is that the physical model (calculation model) used in the numerical simulation is not perfect. That is, the combustion reaction of the object to be processed that occurs inside the combustion furnace is due to the evaporation of water from the object to be treated as a solid air reaction, the thermal decomposition and / or combustion reaction of the object to be processed, and the evaporated water and thermal decomposition reaction. Various chemical reactions represented by the gas phase reaction between the generated thermal decomposition gas and combustion air proceed in parallel, but with all the tens to hundreds of chemical species involved in these reactions. , It is practically impossible to completely elucidate the mutual chemical reaction formulas and reaction parameters and describe them as a calculation model used for simulation. Even if it can be described, a large amount of computer resources and calculation time are required to execute such a calculation.

Therefore, in practice, by using a significantly simplified reaction model, numerical simulations can be performed under the available computer resources and calculation time, but the obtained calculation results are a simplification of the calculation model. It is inevitable that an error due to the above, that is, a model error is included.

The third reason is that it is practically impossible to accurately give the values of the analysis parameters that are indispensable for executing the numerical simulation. For example, when simulating the combustion reaction inside a stoker-type incinerator, the gas composition generated by the thermal decomposition and / or combustion reaction of the object to be treated staying in the upper part of the grate is assumed, and numerical simulation is performed using them as the inflow boundary condition. However, it is difficult to accurately measure the values of these boundary conditions, and in an actual combustion furnace, the processing amount and physical properties of the object to be processed change from moment to moment, so these boundary conditions It becomes difficult to give the value of as a definite value.

In addition, the reaction parameters used in the above-mentioned calculation model that describes the combustion reaction are also generally determined based on the experimental data measured in an idealized environment on a laboratory scale, so that the combustion of the target combustion furnace is performed. It is often uncertain whether the value is appropriate for describing the state.

That is, the object to be processed is processed by executing a numerical simulation that precisely simulates the combustion state inside the process data obtained in the actual combustion furnace, that is, based on the information of the observed values such as temperature and gas composition. In order to estimate the amount of state that cannot be directly measured in an actual combustion furnace, such as information on the supply amount of waste and biomass and fluctuations in physical properties, it is used in observation errors of process data and numerical simulations. There is a problem that a method for appropriately estimating analysis parameters that cannot be deterministically given in advance is required while appropriately considering the model error caused by the incomplete physical model (calculation model).

Therefore, in the present invention, in a combustion furnace using waste or biomass as a object to be processed, observation of actual process data is performed on a state amount that is difficult to measure directly, such as the supply amount and physical properties of the object to be processed. A method for estimating the combustion state of a combustion furnace, which can be accurately estimated based on a value, is provided, and by utilizing the estimation method, even if the supply amount or physical properties of the object to be processed change, they are used. It is an object of the present invention to provide a combustion control method and a combustion control device for a combustion furnace, which can perform appropriate combustion control in accordance with the above.

In order to solve the above-mentioned problems, the method of estimating the combustion state of the combustion furnace, which is the first aspect of the present invention, cannot be directly measured in the furnace of the combustion furnace for combusting the object to be processed. A method for estimating the combustion state of a combustion furnace, which comprises estimating the combustion state by estimating the above state quantities, wherein one or more state quantities are used as explanatory variables and arranged in the combustion furnace. Based on the results obtained by executing a large number of numerical simulations with one or more observables that can be directly measured at one or more observables provided as objective variables, the above 1 The relationship between one or more state quantities and the one or more observables was formulated in advance, and the statistical information of the measured values of the one or more observables actually measured at the observation point and the formulation were formulated. By performing Bayesian estimation based on the relationship between the one or more state quantities and the one or more observables, an estimated value of the one or more state quantities is obtained, and based on the estimated value, It is characterized in that the combustion state of the combustion furnace is estimated.

With this configuration, it is not possible to directly measure in a combustion furnace using waste or biomass as the object to be treated, by appropriately considering the observation error of the process data in the actual combustion furnace and the model error in the numerical simulation. Since the state quantity can be estimated accurately based on the observed values of the actual process data, it is possible to accurately estimate the combustion state of the combustion furnace.

Further, in order to solve the above-mentioned problems, the combustion control method of the combustion furnace, which is the second aspect of the present invention, is
A combustion furnace characterized in that combustion control of the combustion furnace is performed by estimating one or more state quantities that cannot be directly measured in the furnace of the combustion furnace that combusts the object to be processed. A combustion control method in which one or more state quantities are used as explanatory variables, and one or more observables that can be directly measured at one or more observable points arranged in the combustion furnace. Based on the results obtained by executing a large number of numerical simulations with the above as the objective variable, the relationship between the one or more state quantities and the one or more observables is formulated in advance, and the relationship is actually formulated at the observation point. Bayesian estimation is performed based on the statistical information of the measured values of the one or more observables measured in the above, and the relationship between the formulated one or more state quantities and the one or more observables. This is characterized in that an estimated value of the one or more state quantities is obtained, and the combustion control of the combustion furnace is performed based on the estimated value.

With this configuration, it is not possible to directly measure in a combustion furnace using waste or biomass as the object to be treated, by appropriately considering the observation error of the process data in the actual combustion furnace and the model error in the numerical simulation. The state quantity can be estimated accurately based on the observed value of the actual process data, and the combustion control of the combustion furnace can be effectively performed based on the estimated value.

Further, in order to solve the above-mentioned problems, the combustion control device of the combustion furnace according to the third aspect of the present invention cannot be directly measured in the furnace of the combustion furnace that combusts and processes the object to be processed. A combustion control device for a combustion furnace, characterized in that the combustion control of the combustion furnace is performed by estimating the above state quantities, and the one or more state quantities are used as explanatory variables and arranged in the combustion furnace. Based on the results obtained by executing a large number of numerical simulations with one or more observables that can be directly measured at one or more observables provided as objective variables, the above 1 The relationship between one or more state quantities and the one or more observables was formulated in advance, and the statistical information of the measured values of the one or more observables actually measured at the observation point and the formulation were formulated. By performing Bayesian estimation based on the relationship between the one or more state quantities and the one or more observables, an estimated value of the one or more state quantities is obtained, and based on the estimated value, It is characterized in that the combustion control of the combustion furnace is performed.

With this configuration, it is not possible to directly measure in a combustion furnace using waste or biomass as the object to be treated, by appropriately considering the observation error of the process data in the actual combustion furnace and the model error in the numerical simulation. The state quantity can be estimated accurately based on the observed value of the actual process data, and the combustion control of the combustion furnace can be effectively performed based on the estimated value.

Further, in the combustion control device of the combustion furnace according to the fourth aspect of the present invention, the combustion furnace is a stoker type incinerator, and as one or more of the state quantities, it is placed on the grate of the stoker type incinerator. The amount of the object to be supplied, the amount of the object to be treated that stays on the grate, the amount of moisture, combustibles, ash, calorific value, elemental composition, and the amount of the object to be treated are thermally decomposed on the grate. It is characterized by containing any one of the temperature and chemical composition of the pyrolysis gas and / or the combustion gas generated by the combustion reaction.

With this configuration, the amount of the object to be processed supplied on the grate and the amount of the object to be processed staying on the grate, which is difficult to measure directly in the stoker-type incinerator. , Moisture, combustibles, ash, calorific value, elemental composition, temperature and chemical composition of pyrolysis gas and / or combustion gas generated by thermal decomposition and / or combustion reaction of the object to be treated on the grate. It can be estimated well, and the combustion control of the stoker type incinerator can be effectively performed based on the estimated value.

Further, in the combustion control device of the combustion furnace according to the fifth aspect of the present invention, the combustion furnace is a fluidized bed type incinerator, and the fluidized bed of the fluidized bed type incinerator is set as one or more of the state quantities. The amount of the object to be supplied, the amount of water, combustible, ash, calorific value, elemental composition of the object to be treated, and the thermal decomposition of the object to be processed in the fluidized bed. It is characterized by containing any one of the temperature and chemical composition of the thermally decomposed gas and / or the combustion gas generated by the combustion reaction.

With this configuration, the amount of the object to be processed supplied into the fluidized bed and the moisture content of the object to be processed staying in the fluidized bed, which are difficult to measure directly in the fluidized bed incinerator. Accurately estimate the combustible content, ash content, calorific value, elemental composition, and the temperature and chemical composition of the pyrolysis gas and / or combustion gas generated by the thermal decomposition and / or combustion reaction of the object to be treated in the fluidized bed. Furthermore, it becomes possible to effectively control the combustion of the fluidized bed incinerator based on the estimated value.

Further, the combustion control device of the combustion furnace according to the sixth aspect of the present invention has the chemical composition of the pyrolysis gas and / or the combustion gas such as hydrogen, carbon monoxide, carbon dioxide, methane, ethylene, oxygen, nitrogen, and the like. It is characterized by containing the concentration of any one of ammonia, hydrogen cyanide, nitrogen monoxide, nitrogen dioxide, dinitrogen monoxide, and hydrogen chloride.

With this configuration, the pyrolysis gas and / or the thermal decomposition gas generated by the thermal decomposition and / or combustion reaction of the object to be treated, which is difficult to measure directly in the stoker type incinerator or the fluidized bed type incinerator. Accurately estimate the concentrations of hydrogen, carbon monoxide, carbon dioxide, methane, ethylene, oxygen, nitrogen, ammonia, hydrogen cyanide, nitrogen monoxide, nitrogen dioxide, dinitrogen monoxide, and hydrogen chloride as the chemical composition of combustion gas. Further, it is possible to effectively control the combustion of the stoker type incinerator or the fluidized bed type incinerator based on the estimated value.

Further, in the combustion control device of the combustion furnace according to the seventh aspect of the present invention, the one or more observation points are the side wall of the secondary combustion chamber arranged above the grate of the stoker type incinerator and the side wall of the secondary combustion chamber. / Or on the ceiling wall, higher than the surface of the object to be treated staying on the grate of the incinerator of the stoker type, and from the supply position of the secondary air and / or the recirculated exhaust gas supplied to the secondary combustion chamber. Is also characterized in that it is arranged at a low position.

With this configuration, the amount of the object to be processed supplied on the grate and the amount of the object to be processed staying on the grate, which is difficult to measure directly in the stoker type incinerator, are the amount of the object to be processed. , Moisture, combustibles, ash, calorific value, elemental composition, and the temperature and chemical composition of the pyrolysis gas and / or combustion gas generated by the thermal decomposition and / or combustion reaction of the object to be treated on the grate. Since statistical information of observed values of process data with high correlation or sensitivity can be efficiently obtained, even if the number of observed values is small, the above-mentioned state quantity that is difficult to measure directly can be estimated accurately. Further, it is possible to effectively control the combustion of the stoker type incinerator based on the estimated value.

Further, in the combustion control device of the combustion furnace according to the eighth aspect of the present invention, the one or more observation points of the secondary combustion chamber arranged above the fluidized bed portion of the fluidized bed incinerator. Arranged on the side wall and / or ceiling wall at a position higher than the fluidized bed interface of the fluidized bed incinerator and lower than the supply position of the secondary air and / or the recirculated exhaust gas supplied to the secondary combustion chamber. It is characterized by being done.

With this configuration, the amount of the object to be processed supplied into the fluidized bed and the moisture content of the object to be processed staying in the fluidized bed, which are difficult to measure directly in the fluidized bed incinerator. , Combustible content, ash content, calorific value, elemental composition, correlation with the temperature and chemical composition of the pyrolysis gas and / or combustion gas generated by the thermal decomposition and / or combustion reaction of the object to be treated in the fluidized bed. Since statistical information on observed values of highly sensitive process data can be efficiently obtained, even if the number of observed values is small, it is possible to accurately estimate the above-mentioned state quantity that is difficult to measure directly. Further, it is possible to effectively control the combustion of the fluidized bed incinerator based on the estimated value.

Further, in the combustion control device of the combustion furnace according to the ninth aspect of the present invention, the temperature of the gas in the furnace and / or the furnace measured at the one or more observation points as the one or more observation amounts. It is characterized by containing the chemical composition of the internal gas.

With this configuration, the retention amount, water content, combustible content, ash content, calorific value, elemental composition, and the subject to be processed are difficult to measure directly in a stoker-type incinerator or a fluidized bed-type incinerator. Efficiently obtain statistical information on observed values of process data with particularly high correlation or sensitivity to the temperature and chemical composition of the pyrolysis gas and / or combustion gas generated by the thermal decomposition and / or combustion reaction of the processed material. Therefore, even if the number of observed values is even smaller, it is possible to accurately estimate the amount of state that is difficult to measure directly, and based on the estimated values, the fluidized bed incinerator Combustion control can be effectively performed.

Further, in the combustion control device of the combustion furnace according to the tenth aspect of the present invention, the chemical composition of the gas in the furnace includes hydrogen, carbon monoxide, carbon dioxide, methane, ethylene, oxygen, nitrogen, ammonia, hydrogen cyanide, and one. It is characterized by containing the concentration of any one of nitrogen oxide, nitrogen dioxide, nitrous oxide, and hydrogen chloride.

With this configuration, the retention amount, water content, combustible content, ash content, calorific value, elemental composition, and the subject to be processed are difficult to measure directly in a stoker-type incinerator or a fluidized bed-type incinerator. Efficiently obtain statistical information on observed values of process data with extremely high correlation or sensitivity with the temperature and chemical composition of the pyrolysis gas and / or combustion gas generated by the thermal decomposition and / or combustion reaction of the processed material. Therefore, even if the number of observed values is extremely small, it is possible to accurately estimate the amount of state that is difficult to measure directly, and based on the estimated values, the fluidized bed incinerator Combustion control can be effectively performed.

Further, in the combustion control method of the combustion furnace according to the eleventh aspect of the present invention, the feed rate of the grate of the stoker type incinerator and the flow bed type incinerator are based on the estimated value of the one or more state quantities. The rate of supply of the object to be processed to the furnace, the flow rate of the primary air and / or the recirculated exhaust gas supplied from the lower part of the grate of the stoker incinerator or the lower part of the fluidized layer of the fluidized bed incinerator, the stoker incinerator or In the furnace to reduce the flow rate of secondary air supplied to the secondary combustion chamber of the fluidized bed incinerator and / or the flow rate of recirculated exhaust gas, and the temperature inside the stoker incinerator or the fluidized bed incinerator. It is characterized by adjusting at least one of the flow rate of the cooling water supplied to the incinerator and the flow rate of urea water or ammonia water supplied as a denitration reaction agent in the stoker type incinerator or the fluidized bed type incinerator. do.

With this configuration, the actual combustion furnace, such as information on the supply amount of waste and biomass as the object to be treated and the fluctuation of physical properties, which is the root cause of combustion fluctuation in the stoker type incinerator or the fluidized bed type incinerator. The amount of state that cannot be directly measured in is estimated by numerical simulation based on the process data obtained in the actual combustion furnace, and based on the estimated value, the stoker type incinerator or the fluidized bed type incinerator Combustion control can be effectively performed.

It is a figure which shows the step of the method of estimating the combustion state of a combustion furnace by one Embodiment. It is a figure which shows the process flow when the method of estimating the combustion state of a combustion furnace by one Embodiment, the combustion control method, and the combustion control device are applied to a stoker type incinerator. It is a figure which shows the process flow when the method of estimating the combustion state of a combustion furnace by one Embodiment, the combustion control method, and the combustion control device are applied to a fluidized bed type incinerator.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the steps of a method for estimating the combustion state of a combustion furnace according to an embodiment of the present invention.

First, as step 1, a state quantity that cannot be directly measured in the combustion furnace and is an object of estimation, an observable that is used in the estimation and can be directly measured, and an observation point thereof are defined.

As will be described later, since the state quantity to be estimated in the present embodiment is estimated based on the statistical information of the observed quantity obtained at the observed point, the observed quantity or the number of observed points is large in principle. The more accurately the state quantity to be estimated can be estimated. However, if the amount of observation or the number of observation points is large, problems such as the installation cost of measuring equipment required for observation, the labor of measurement work, and the amount of calculation for estimation increase, so it is defined in step 1. It is desirable to appropriately set the observation amount or the number of observation points in consideration of the estimation accuracy of the state quantity to be estimated and the above-mentioned cost or labor.

Next, as step 2, a large number of numerical simulations are executed with the state quantity as an explanatory variable and the observed quantity as an objective variable.

As a method of numerical simulation in this embodiment, numerical fluid simulation involving chemical species transport and chemical reaction based on the finite volume method is used. Specifically, a large number of calculation conditions in which the value of the state quantity as an explanatory variable is changed are created, a large number of numerical simulations given these calculation conditions are executed, and the value of the state quantity as an explanatory variable is used. , The value of the observed amount as the corresponding objective variable is saved as the execution result of the numerical simulation.

Next, as step 3, the relationship between the state quantity and the corresponding observed quantity value is formulated based on the execution result of the numerical simulation executed in step 2.

As a method for formulating the relationship between the state quantity and the early observation amount in the present embodiment, a method such as multivariate polynomial regression, ridge regression, lasso regression, or sparse regression such as elastic net is selected. It is configured to be usable. The formulation method is not necessarily limited to these, and a conventional method capable of appropriately and accurately formulating the relationship between the state quantity and the observed quantity can be appropriately adopted.

Since a considerable amount of calculation time is required to execute a large number of numerical simulations in step 2, in the present embodiment, before starting the combustion control of the target combustion furnace, from step 1 above. The work up to step 3 is configured to be executed in advance. Of course, if the calculation time required to execute the numerical simulation can be shortened practically enough, the work from step 1 to step 3 or the work of step 2 and step 3 can be performed in parallel with the combustion control of the target combustion furnace. Work can also be performed in real time.

Next, as step 4, the measured value of the observed amount is obtained at the observation point in the actual combustion furnace. As a method for obtaining the measured value, it can be appropriately selected and used from the existing measuring instruments and measuring methods according to the type of the observed amount.

Next, as step 5, Bayesian estimation is performed based on the statistical information of the measured values of the observed amount and the relationship between the state amount and the observed amount formulated in step 3, and the above one Obtain the above estimated value of the state quantity.

The object of this step 5 is to reversely estimate the value of the state quantity that cannot be directly measured, which gives them, from the information of the observed quantity obtained in step 4.

Here, as described above, the observed amount obtained in step 4 includes the measurement accuracy of the measuring instrument, the time lag in measurement, the observation error due to the use of the measuring instrument itself, and the like. Further, in a combustion furnace, the operating state is generally not steady, and is usually an unsteady operating state including temporal fluctuations based on changes in the amount of processed material and properties. .. Therefore, the value of the observed amount in an actual combustion furnace is usually obtained only as a statistical distribution with variation.

Further, when the combustion control of the combustion furnace is targeted as in the present embodiment, since the basic equations governing the flow field and the reaction field in the furnace have non-linearity, the state quantity formulated in step 3 is used. The relationship with the observable generally has non-linearity.

For these reasons, that is, the value of the observable is not a definite value but is obtained only as a statistical distribution with variation, and the relationship between the state quantity and the observable generally has non-linearity. From the relationship between the formulated state quantity and the observed quantity and the information of the observed quantity obtained in the actual combustion furnace, the value of the state quantity giving those values is analytically or deterministically obtained. Back calculation is generally impossible.

Therefore, in the present embodiment, the state quantity is estimated by calculating the posterior probability distribution of the state quantity based on the statistical information of the observed quantity obtained by using Bayesian estimation. ing.

As the Bayesian estimation method for obtaining the posterior probability distribution of the state quantity, for example, Markov chain Monte Carlo method or Hamiltonian Monte Carlo method can be used, but the method is not necessarily limited to this, and the method formulated in step 3 is not always limited. From the relationship between the state quantity and the observed quantity and the statistical information of the observed quantity obtained in the actual combustion furnace, a method capable of appropriately estimating the posterior probability distribution of the state quantity giving those values can be estimated. It may be used.

Finally, as step 6, the combustion state of the combustion furnace is estimated with reference to the estimation result of the one or more state quantities obtained in step 5, that is, the estimation result of the state quantity that cannot be directly measured in the combustion furnace. ..

Although the preferred embodiment of the present invention has been described above, the definition of the state quantity and the observed quantity, the measurement method of the observed quantity at the observation point, and the specific control target and the control method using the estimated value of the obtained state quantity. As for the matters such as the details of the above, as in the examples illustrated below, various changes or modifications may be made according to the type of the combustion furnace to be controlled without departing from the gist of the present invention. can.

FIG. 2 shows, as an embodiment of the present invention, a method for estimating the combustion state of the combustion furnace according to the above-described embodiment, a combustion control method, and a process flow when the combustion control device is applied to the stoker type incinerator plant 20. Is. That is, in this embodiment, the incinerator 20 is mainly composed of a stoker-type incinerator 21.

The object a to be processed, which is thrown into the waste hopper 23 by the action of the waste crane 22, is sent into the stoker type incinerator 21 by the action of the waste supply device 24. The waste supply device 24 is driven by a hydraulic cylinder, and the supply speed of the object to be processed a can be adjusted by changing the amount of oil or the oil pressure thereof.

The object to be processed a sent into the stoker-type incinerator 21 is sequentially transferred to the drying zone 21a, the combustion zone 21b, and the post-combustion zone 21c by the action of the waste feeding devices 25a to 25c, and the primary combustion is performed in the process. It is incinerated by reacting with air ba to bc. Further, the combustible gas components generated from the dry zone 21a, the combustion zone 21b, and the post-combustion zone 21c react with the secondary combustion air bd in their upper space, that is, the secondary combustion chamber, and are completely burned. The unburned residue is discharged as main ash c. Here, the dust feeding devices 25a to 25c are driven by a hydraulic cylinder, and the transfer speed of the object to be processed a can be adjusted by changing the amount of oil or the oil pressure thereof.

The primary combustion air ba to bc are boosted to a predetermined pressure by the primary combustion air blower 26, and then pass through the primary combustion air adjusting dampers 27a to 27c to lower the dry zone 21a, the combustion zone 21b, and the post-combustion zone 21c. Is supplied to the inside of the stoker type incinerator 21. Further, the secondary combustion air bd is boosted to a predetermined pressure by the secondary combustion air blower 28, and then supplied to the inside of the stoker type incinerator 21 via the secondary combustion air adjustment damper 29. Here, the flow rates of the primary combustion air ba, bb, bc and the secondary combustion air bd supplied are the rotation speed of the primary combustion air blower 26 to the secondary combustion air blower 28, and the primary combustion air adjusting dampers 27a to 27c or more. It can be adjusted by changing the opening degree of the secondary combustion air adjusting damper 29.

The combustion exhaust gas d generated by the combustion of the waste (processed object) a inside the stoker-type incinerator 21 is discharged from the outlet of the stoker-type incinerator 21 and cooled via the waste heat boiler 30. , Hazardous substances and fly ash are removed via an exhaust gas purification device 31 composed of a chemical spraying facility, a bag filter, a denitration catalyst tower, etc., and then discharged from the chimney 32 to the atmosphere.

A part of the combustion exhaust gas d branches inside or downstream of the exhaust gas purification device 31, and is returned to the incinerator 21 as the recirculated exhaust gas f via the exhaust gas recirculation blower 33. Here, the flow rate of the returned recirculated exhaust gas f can be adjusted by changing the rotation speed of the exhaust gas recirculation blower 33 and the opening degree of the recirculated exhaust gas amount adjusting damper 34.

Further, in the waste heat boiler 30, steam g is generated by heat exchange with the combustion exhaust gas d, and this is guided by the steam turbine generator 35 to be used for power generation.

Further, the incinerator cooling water h supplied to lower the temperature inside the incinerator and the denitration agent i used for the denitration reaction in the furnace are supplied to the secondary combustion chamber of the incinerator 21. As the denitration agent i, urea water or ammonia water is generally used. Here, the flow rates of the in-core cooling water h and the denitration agent i can be adjusted by changing the opening degrees of the in-core cooling water amount adjusting valve 36 and the denitration agent amount adjusting valve 37, respectively.

Further, in the incinerator plant 20 of this embodiment, a thermometer is used for the purpose of detecting whether the combustion state of the waste in the incinerator 21 is properly maintained and the desired amount of steam is obtained in the waste heat boiler 30. , Pressure gauges, flow meters, exhaust gas concentration meters, and many other measuring instruments are installed. Among these many measuring instruments, those particularly used for managing the combustion state are a flame position detector 41, an incinerator outlet exhaust gas thermometer 42, a boiler outlet exhaust gas oxygen concentration meter 43, a chimney exhaust gas concentration meter 44, and a steam flow meter. 45 is illustrated in FIG.

The flame position detecting device 41 is a device that effectively detects the position of the flame inside the incinerator 21 by performing predetermined image processing on the image information obtained about the internal condition of the stoker type incinerator 21. It is configured and installed as.

The incinerator outlet exhaust gas thermometer 42 is configured and installed so that the temperature of the combustion exhaust gas d at the outlet of the stoker-type incinerator 21 can be effectively measured.

The boiler outlet exhaust gas oxygen concentration meter 43 is configured and installed so that the oxygen concentration of the combustion exhaust gas d at the outlet of the waste heat boiler 30 can be effectively measured.

The chimney exhaust gas concentration meter 44 has an effect on the concentrations of various gas components contained in the combustion exhaust gas d in the chimney 32, specifically, the concentrations of oxygen, carbon monoxide, nitrogen oxides, sulfur oxides, hydrogen chloride, mercury and the like. It is configured and installed so that it can be measured in a targeted manner.

The steam flow meter 45 is configured and installed so that the amount of steam generated in the waste heat boiler 30 can be effectively measured.

The information obtained from these measuring instruments is transmitted to the operation control device 50, and the operation control of the incinerator 21 is performed based on the information. As the operation control device 50 in this embodiment, a distributed control system (DCS: Distributed Control System) is used.

The operation control device 50 controls the operation of the incinerator 21 so that the control indicators such as the flame position, the incinerator outlet exhaust gas temperature, the boiler outlet exhaust gas oxygen concentration, the chimney exhaust gas concentration, and the steam flow rate do not deviate from the predetermined control range. For the purpose of this, control logic is implemented with those control indicators themselves and physical quantities closely related to those control indicators as control quantities. Specifically, referring to the measured values such as the flame position, the incinerator outlet exhaust gas temperature, the boiler outlet exhaust gas oxygen concentration, the chimney exhaust gas concentration, and the steam flow rate, the waste supply device 24 and the waste feed devices 25a to 25c Oil amount and oil pressure, primary combustion air blower 26, secondary combustion air blower 28 and exhaust gas recirculation blower 33 rotation speed, primary combustion air adjustment dampers 27a to 27c, secondary combustion air adjustment damper 29, recirculation exhaust gas amount The opening degree of the adjusting damper 34, the incinerator cooling water amount adjusting valve 36, and the denitration chemical amount adjusting valve 37 is adjusted. As a result, the operation of the incinerator 21 is controlled so that the combustion state of the waste in the incinerator 21 is appropriately maintained and a desired steam flow rate can be obtained.

In addition to these functions, in the operation control device 50 in this embodiment, the supply amount and physical properties of the object to be processed a in the furnace, which is a state amount that cannot be generally directly measured in the stoker-type incinerator 21. Fluctuation information, more specifically, the supply amount of the object to be processed a supplied on the grate of the stoker-type incinerator 21, the retention amount of the object a to be processed staying on the grate, the moisture content, and the like. Combustible content, ash content, calorific value and element composition, and the temperature and chemical composition of the thermal decomposition gas and / or combustion gas generated by the thermal decomposition and / or combustion reaction of the object a to be treated on the grate. It is configured so that it can be estimated by the combustion state estimation device 70 and the combustion control of the incinerator 21 can be performed based on the estimated value.

The chemical composition of the pyrolysis gas and / or combustion gas includes hydrogen, carbon monoxide, carbon dioxide, methane, ethylene, oxygen, nitrogen, ammonia, hydrogen cyanide, nitrogen monoxide, nitrogen dioxide, and nitrous oxide. Includes the concentration of hydrogen cyanide.

Therefore, in this embodiment, a plurality of observation points 61 are arranged on the side wall of the secondary combustion chamber of the stoker type incinerator 21 in order to estimate these state quantities that cannot be directly measured. Specifically, it is the side wall of the secondary combustion chamber, higher than the surface of the object a to be treated that stays on the grate, and the secondary combustion air bd and / or recirculation supplied to the secondary combustion chamber. Three observation points 61a to 61c are arranged at positions lower than the supply position of the exhaust gas f.

The reason why it is desirable to dispose the observation point 61 at the above position is that in this embodiment, the retention amount, moisture, combustible content, ash content, calorific value, elemental composition, etc. of the object to be treated a staying on the grate This is because it is considered that the value of the state quantity to be estimated has a very high correlation with the value of the observed quantity obtained at a position as close as possible to the surface of the object to be processed a staying on the grate. That is, when the position of the observation point 61 is separated from the surface of the object to be processed a staying on the grate by a certain distance or more, the correlation between the state quantity to be estimated and the observed quantity is affected by the flow field and the reaction field. Therefore, it becomes difficult to accurately estimate the state quantity. Further, if the observation point 61 is arranged at a position higher than the supply position of the secondary combustion air bd and / or the recirculated exhaust gas f, a flow field based on the supply of the secondary combustion air bd and / or the recirculated exhaust gas f can be generated. Due to the influence of changes in the reaction field, it becomes extremely difficult to obtain an observable with a high correlation with the state quantity.

In FIG. 2, the observation point 61 is the number of divisions in the longitudinal direction of the waste feed devices 25a to 25c and the primary combustion air supply systems ba to bc that can be independently controlled in the stoker type incinerator 21 (here, the number of divisions in the longitudinal direction). Although it is shown that three observation points 61a to 61c are arranged corresponding to 3), when the scale of the incinerator 21 is large and the number of divisions in the longitudinal direction is different, the number of divisions in the longitudinal direction is different accordingly. It is desirable to increase or decrease the number of observation points as appropriate. Further, with respect to the number of divisions in the longitudinal direction, the positional relationship with the surface of the object to be treated a staying on the grate and the positional relationship with the supply position of the secondary combustion air bd and / or the recirculated exhaust gas f. It is also possible to arrange a plurality of observation points in the vertical direction within the range that satisfies the above constraint. Alternatively, the observation points may be installed on the front and rear walls or the ceiling wall instead of the side walls of the incinerator 21.

The observation points 61a to 61c in this embodiment are specifically configured by connecting an instrument according to the observed amount to be measured to a measuring hole of a nozzle structure provided on the side wall of the stoker type incinerator 21. .. That is, in this embodiment, thermocouples and gas densitometers are installed at the respective observation points so that the temperature and chemical composition of the gas in the furnace can be observed as the observation amounts at the observation points 61a to 61c.

Specifically, the chemical composition of the gas in the furnace includes hydrogen, carbon monoxide, carbon dioxide, methane, ethylene, oxygen, nitrogen, ammonia, hydrogen cyanide, nitrogen monoxide, nitrogen dioxide, nitrous oxide, hydrogen chloride, etc. It is configured so that a part or all of the concentrations can be appropriately selected and measured. These gas concentrations may be measured using a measuring instrument or measuring method capable of continuously measuring, or may be measured using a measuring instrument or measuring method capable of measuring intermittently or batchily. ..

Next, the configuration and function of the combustion state estimation device 70 in this embodiment will be described.

The combustion state estimation device 70 in this embodiment is configured to include a simulation execution unit 71, a formulation unit 72, an observation amount input unit 73, a state amount estimation unit 74, and an estimated value output unit 75.

The simulation execution unit 71 executes a large number of numerical simulations in which a predefined state quantity to be estimated is used as an explanatory variable and an observed quantity at an observation point is used as an objective variable.

In the formulation unit 72, the relationship between the state quantity and the corresponding observed quantity value is formulated based on the execution result of the simulation executed by the simulation execution unit 71.

The observation amount input unit 73 inputs information on the observation amount obtained at the observation point 61 by actually operating the stoker type incinerator 21.

The state quantity estimation unit 74 performs Bayesian estimation based on the statistical information of the observation quantity obtained at the observation point 61 and the relationship between the state quantity and the observation quantity formulated by the formulation unit 72. To obtain an estimated value of the state quantity to be estimated.

The estimated value output unit 75 outputs an estimated value of the state quantity to be estimated to the operation control device 50, and the operation control device 50 performs combustion control of the incinerator 21 based on the information. Will be.

Hereinafter, the state quantity to be estimated in this embodiment and the specific configuration of the combustion control of the incinerator 21 based on the state quantity will be described.

First, in the stoker-type incinerator 21 of the present embodiment, the amount of the object to be treated a that stays on the grate of each of the drying zone 21a, the combustion zone 21b, and the post-combustion zone 21c is set as the state amount to be estimated, and combustion is performed. By adjusting the operating speeds of the waste supply device 24 and the waste feed devices 25a to 25c based on the estimated value of the state quantity sequentially calculated by the state estimation device 70, the object to be processed on each of the grate is adjusted. Control is performed so that the retention amount of the object a becomes constant.

More specifically, for example, when the estimated value of the retention amount of the object to be processed a on the grate of the dry zone 21a tends to decrease, the operation speed of the waste supply device 24 is increased to increase the operation speed of the dry zone 21a. Adjustments are made to increase the amount of the object a to be treated on the grate. Alternatively, when the estimated value of the retention amount of the object to be processed a on the grate of the combustion zone 21b tends to increase, the operating speed of the dust feeding device 25a is reduced to cover the object a on the grate of the combustion zone 21b. Adjustments are made to reduce the amount of retention of the processed product a.

Next, in the stoker type incinerator 21 of the present embodiment, the composition of the pyrolysis gas or the combustion gas generated from the object to be treated a staying on the grate of each of the drying zone 21a, the combustion zone 21b, and the post-combustion zone 21c. Is the state amount to be estimated, and the opening degree of the primary combustion air adjusting dampers 27a to 27c is adjusted based on the estimated value of the state amount sequentially calculated by the combustion state estimation device 70 to adjust each of the above. Control is performed so as to keep the progress of the thermal decomposition or combustion reaction of the object a to be treated on the grate constant.

More specifically, for example, when the estimated value of the concentration of combustible gas contained in the pyrolysis gas generated from the object a to be treated on the grate of the dry zone 21a, for example, the carbon monoxide concentration tends to increase, it is dried. Since it is presumed that the thermal decomposition reaction of the object to be processed a on the grate of the band 21a is promoted, the primary combustion air supplied to the dry zone 21a by lowering the opening degree of the primary combustion air adjusting damper 27a. By reducing the flow rate of ba, adjustments are made so as to suppress the thermal decomposition reaction of the object to be processed a on the grate of the dry zone 21a. Alternatively, when the estimated value of the combustible gas component, for example, the carbon monoxide concentration contained in the combustion gas generated from the object a to be processed on the grate of the post-combustion zone 21c tends to increase, the subject in the post-combustion zone 21c. Since there is a concern that a sufficient amount of primary combustion air bc is not supplied for the combustion reaction of the unburned portion of the processed product a, by increasing the opening degree of the primary combustion air adjusting damper 27c, the post-combustion zone 21c is reached. By increasing the flow rate of the supplied primary combustion air bc, adjustments are made to ensure that the combustion reaction of the unburned portion of the object a to be treated in the post-combustion zone 21c proceeds.

Further, in the stoker-type incinerator 21 of the present embodiment, the composition of the pyrolysis gas or the combustion gas generated from the object to be treated a staying on the grate of each of the drying zone 21a, the combustion zone 21b, and the post-combustion zone 21c is determined. The state amount to be estimated is set, and the opening degree of the secondary combustion air adjusting damper 29 is adjusted based on the estimated value of the state amount sequentially calculated by the combustion state estimation device 70, thereby in the secondary combustion chamber. Control is performed so as to reliably supply the amount of secondary combustion air bd required for the combustion reaction.

More specifically, for example, a combustible gas component contained in the pyrolysis gas generated from the object a to be treated on each grate of the dry zone 21a, the combustion zone 21b, and the post-combustion zone 21c, such as hydrogen concentration and carbon monoxide. When the sum of the estimated concentrations is increasing, it is estimated that the thermal decomposition and combustion reaction of the object a to be processed on the grate are becoming active. Therefore, the secondary combustion air adjustment damper 29 By increasing the flow rate of the secondary combustion air bd supplied to the secondary combustion chamber by increasing the opening degree, the amount of the secondary combustion air bd required for the combustion reaction in the secondary combustion chamber is reliably supplied. Adjustments are made.

In the same manner as described above, the amount of retention of the object to be processed a on the grate and the estimated value of its physical properties estimated by the combustion state estimation device 70, or the pyrolysis gas or combustion generated from the object a to be processed on the grate. By grasping the transition of the combustion state in the furnace based on the transition of the estimated value of the gas composition, the flow rate of the incinerator cooling water h supplied to adjust the temperature in the incinerator 21 and the incinerator It can also be configured to adjust the supply amount of the reaction agent i for the denitration reaction in 21 and the like.

In the combustion control method in the present embodiment illustrated above, conventional feedback combustion based on information obtained at a later stage of the incinerator process, such as incinerator outlet exhaust gas temperature, boiler outlet exhaust gas oxygen concentration, and chimney exhaust gas concentration. Compared to the control method, feed-forward combustion control is performed according to changes in the amount of the object a to be treated on the grate and its physical properties, changes in the progress of thermal decomposition and combustion reaction on the grate, and the like. Therefore, it is possible to follow those fluctuations and perform appropriate combustion control.

FIG. 3 shows, as another embodiment of the present invention, a method for estimating the combustion state of the combustion furnace according to the above-described embodiment, a combustion control method, and a process flow when the combustion control device is applied to the fluidized bed incinerator plant 120. It is a thing. That is, in this embodiment, the incinerator 120 is mainly composed of a fluidized bed incinerator 121.

The object a to be processed, which has been introduced into the waste hopper 23 by the action of the waste crane 22, is sent into the fluidized bed incinerator 121 by the action of the waste supply device 24. Here, the waste supply device 24 is driven by an electric motor, and the supply speed of the object to be processed a can be adjusted by changing the rotation speed thereof.

The object to be processed a sent into the fluidized bed incinerator 121 is thermally decomposed or burned by reacting with the primary combustion air (fluid air) ba in the fluidized bed portion 121a below the fluidized bed portion 121a. Here, the fluidized bed portion 121a is filled with a fluidized medium made of solid particles such as silica sand in order to form the fluidized bed, and the primary combustion air ba is provided through an air disperser (not shown) arranged on the bottom surface thereof. A fluidized bed is formed by supplying it as fluidized air. The pyrolysis or combustion gas component generated from the fluidized bed portion 121a reacts with the secondary combustion air bd in the secondary combustion chamber which is the upper space of the fluidized bed portion 121a and is completely burned. Of the unburned residue, the large-diameter incombustible material is discharged from the bottom of the furnace as the main ash c together with the flow medium by the action of a flow medium discharge device (not shown).

The primary combustion air ba is boosted to a predetermined pressure by the primary combustion air blower 26, and then the primary combustion air ba is boosted to a predetermined pressure.
It is supplied to the fluidized bed portion 121a of the fluidized bed incinerator 121 via the combustion air adjusting damper 27a and the air disperser. Further, the secondary combustion air bd is boosted to a predetermined pressure by the secondary combustion air blower 28, and then supplied to the secondary combustion chamber of the fluidized bed incinerator 121 via the secondary combustion air adjusting damper 29. NS. Here, the flow rates of the primary combustion air ba and the secondary combustion air bd to be supplied include the rotation speed of the primary combustion air blower 26 to the secondary combustion air blower 28 and the primary combustion air adjustment damper 27a to the secondary combustion air adjustment damper. It can be adjusted by changing the opening degree of 29.

Hereinafter, in the present embodiment, the handling of the combustion exhaust gas d generated by the combustion of the object a to be processed inside the fluidized bed incinerator 121, and the fluidized bed incineration of the recirculated exhaust gas f via the exhaust gas recirculation blower 33. Recirculation to the furnace 121, utilization of power generated by the steam turbine generator 35, supply of in-furnace cooling water h and denitration agent i to the secondary combustion chamber of the fluidized bed incinerator 121, and measuring instruments 41 to 41 The description of the basic configuration and the like of the operation control device 50 and the operation control device 50 will be omitted because they overlap with the description in the embodiment shown in FIG.

By the way, in the operation control device 50 in the embodiment shown in FIG. 3, the heat of the object a to be processed inside the fluidized bed portion 121a, which is a state quantity that cannot be generally directly measured in the fluidized bed incinerator 121. Information on fluctuations in the decomposition or combustion reaction, more specifically, the amount of the object to be processed a supplied to the inside of the fluidized bed portion 121a, the amount of the object to be processed a retained in the fluidized bed portion 121a, and the water content. , Combustible content, ash content, calorific value and element composition, and the temperature and chemical composition of the thermal decomposition gas or combustion gas generated by the thermal decomposition or combustion reaction of the object a to be treated in the fluidized bed portion 121a are in a combustion state. It is estimated by the estimation device 70, and the information is configured to be used for combustion control of the incinerator 121. The chemical composition of the pyrolysis gas and / or combustion gas includes hydrogen, carbon monoxide, carbon dioxide, methane, ethylene, oxygen, nitrogen, ammonia, hydrogen cyanide, nitrogen monoxide, nitrogen dioxide, and nitrous oxide. Includes the concentration of hydrogen cyanide.

In this embodiment, an observation point 61 is arranged on the side wall of the secondary combustion chamber of the fluidized bed incinerator 121 in order to estimate these state quantities that cannot be directly measured. Specifically, at a position higher than the fluidized bed interface of the fluidized bed incinerator 121 and lower than the supply position of the secondary combustion air bd and / or the recirculated exhaust gas f supplied to the secondary combustion chamber. One or more observation points 61 are arranged.

The reason why it is desirable to dispose the observation point 61 at the above position is that the retention amount, water content, combustible content, ash content, calorific value, elemental composition, etc. of the object to be treated a staying in the fluidized bed portion 121a, etc. This is because the value of the state quantity to be estimated in is considered to have a very high correlation with the value of the observed quantity obtained at a position as close as possible to the fluidized bed interface. That is, if the position of the observation point 61 is separated from the fluid layer interface by a certain distance or more, the correlation between the state quantity to be estimated and the observed quantity becomes low due to the influence of the flow field and the reaction field. It becomes difficult to estimate the quantity accurately. Further, if the observation point 61 is arranged at a position higher than the supply position of the secondary combustion air bd and / or the recirculated exhaust gas f, a flow field based on the supply of the secondary combustion air bd and / or the recirculated exhaust gas f can be generated. Due to the influence of changes in the reaction field, it becomes extremely difficult to obtain an observable with a high correlation with the state quantity.

In FIG. 3, it is drawn that only one observation point 61 is arranged, but even if a plurality of observation points are installed at the same height according to the dimensions of the fluidized bed incinerator 121. Also, a plurality of observation points are provided in the vertical direction within a range that satisfies the constraints of the positional relationship with the fluidized bed interface and the positional relationship with the supply position of the secondary combustion air bd and / or the recirculated exhaust gas f. It can also be placed. Alternatively, an observation point may be installed on the ceiling wall of the incinerator 121.

The specific structure of these observation points 61, the connection method of the instrument, the setting method of the observed amount, and the configuration of the combustion state estimation device 70 in this embodiment are described with reference to the embodiment described with reference to FIG. Since it is duplicated, its description is omitted.

Hereinafter, the state quantity to be estimated in this embodiment and the specific configuration of the combustion control of the incinerator 121 based on the state quantity will be described.

First, in the fluidized bed incinerator 121 of the present embodiment, the retention amount of the object to be processed a staying in the fluidized bed portion 121a is set as the state amount to be estimated, and the state is sequentially calculated by the combustion state estimation device 70. By adjusting the operating speed of the waste supply device 24 based on the estimated value of the amount, control is performed so that the amount of the object to be processed a staying in the fluidized bed portion 121a becomes constant.

More specifically, for example, when the estimated value of the retention amount of the object to be processed a staying in the fluidized bed portion 121a tends to decrease, the operation speed of the waste supply device 24 is increased to cause the fluidized bed portion 121a. Adjustments are made to increase the amount of retained material a to be treated.

Next, in the fluidized bed incinerator 121 of the present embodiment, the composition of the pyrolysis gas or the combustion gas generated from the object to be processed a staying in the fluidized bed portion 121a is set as the state quantity to be estimated, and the combustion state estimation device 70 By adjusting the opening degree of the secondary combustion air adjusting damper 29 based on the estimated value of the state amount sequentially calculated in the above, the amount of secondary combustion air bd required for the combustion reaction in the secondary combustion chamber. Is controlled so as to reliably supply.

More specifically, for example, when the estimated value of the combustible gas component contained in the pyrolysis gas generated from the object to be treated a staying in the fluidized bed portion 121a, for example, the hydrogen concentration or the carbon monoxide concentration tends to increase. Since it is estimated that the thermal decomposition and combustion reaction of the object to be processed a in the fluidized bed portion 121a are becoming active, the secondary combustion air adjusting damper 29 is supplied to the secondary combustion chamber by increasing the opening degree. By increasing the flow rate of the secondary combustion air bd in advance, adjustment is performed so as to reliably supply the amount of the secondary combustion air bd required for the combustion reaction in the secondary combustion chamber.

In the same manner as described above, the amount of the object to be processed a in the fluidized bed portion 121a estimated by the combustion state estimation device 70 and the transition of the estimated value of the physical properties thereof, or the generation from the object to be processed a accumulated in the fluidized bed portion 121a. By grasping the transition of the combustion state in the furnace based on the transition of the estimated value of the composition of the pyrolysis gas, the flow rate of the cooling water h in the furnace supplied to adjust the temperature in the incinerator 121 and the flow rate of the cooling water h in the furnace , The supply amount of the reaction agent i for the denitration reaction in the incinerator 121 can also be adjusted.

Also in the combustion control method in the present embodiment illustrated above, the incinerator outlet exhaust gas temperature, the boiler outlet exhaust gas oxygen concentration, and the chimney exhaust gas are the same as in the embodiment for the stoker type incinerator 21 described with reference to FIG. Compared with the conventional feedback combustion control method based on the information obtained in the later stage of the incinerator such as the concentration, the amount of the object to be treated a in the fluidized bed portion 121a, the fluctuation of its physical properties, and the fluidized bed portion 121a Since it is possible to perform feed-forward combustion control according to the fluctuation of the progress of the thermal decomposition and the combustion reaction in the above, it is possible to perform appropriate combustion control by following the fluctuation. ..

Although the details of the embodiments and examples of the present invention have been described above, the present invention is not limited to the above-mentioned examples and embodiments, and is described in the claims, the specification and the drawings. It is possible to make various changes or modifications within the range that does not deviate from the technical idea.

20 Stoker-type incineration plant 21 Stoker-type incinerator 21a Drying zone 21b Combustion zone 21c Post-combustion zone 22 Garbage crane 23 Garbage hopper 24 Garbage supply device 25a to 25c Garbage feeding device 26 Primary combustion air blower 27a to 27c Primary combustion air adjustment damper 28 Secondary combustion air blower 29 Secondary combustion air adjustment damper 30 Waste heat boiler 31 Exhaust gas purification device 32 Chimney 33 Exhaust gas recirculation blower 34 Recirculation exhaust gas amount adjustment damper 35 Steam turbine generator 36 In-core cooling water amount adjustment valve 37 Denitration chemical amount Control valve 41 Flame position detector 42 Incinerator outlet exhaust gas thermometer 43 Boiler outlet exhaust gas oxygen concentration meter 44 Chimney exhaust gas concentration meter 45 Steam flow meter 50 Operation control device 61, 61a to 61c Observation point 70 Combustion state estimation device 71 Simulation execution unit 72 Formulation unit 73 Observation amount input unit 74 State quantity estimation unit 75 Estimated value output unit 120 Flow bed type incineration plant 121 Flow bed type incinerator 121 a Flow layer part a Processed object ba to bc Primary combustion air bd Secondary combustion air c Main ash d Combustion exhaust gas f Recirculated exhaust gas g Steam h In-core cooling water i Denitration agent

Claims (11)

A method of estimating the combustion state of a combustion furnace by estimating one or more state quantities that cannot be directly measured in the furnace of the combustion furnace that burns the object to be processed.
A plurality of state quantities having one or more state quantities as explanatory variables and one or more observables that can be directly measured at one or more observation points arranged in the combustion furnace as objective variables. Steps to perform a numerical simulation of
A step of formulating the relationship between the one or more state quantities and the one or more observed quantities based on the results obtained by executing the plurality of numerical simulations.
The step of actually measuring at one or more observation points and obtaining the measured value of the one or more observation amounts, and
Based on the statistical information of the measured values of the one or more observed quantities obtained in the actual measurement, and the relationship between the one or more state quantities formulated and the one or more observed quantities. , A step of obtaining an estimate of one or more state quantities by performing Bayesian inference.
A step of estimating the combustion state of the combustion furnace based on the estimated value, and
A method for estimating the combustion state of a combustion furnace, which comprises. A method of controlling combustion in a combustion furnace for combusting an object to be processed by estimating one or more state quantities that cannot be directly measured.
A plurality of state quantities having one or more state quantities as explanatory variables and one or more observables that can be directly measured at one or more observation points arranged in the combustion furnace as objective variables. Steps to perform a numerical simulation of
A step of formulating the relationship between the one or more state quantities and the one or more observed quantities based on the results obtained by executing the plurality of numerical simulations.
The step of actually measuring at one or more observation points and obtaining the measured value of the one or more observation amounts, and
Based on the statistical information of the measured values of the one or more observed quantities obtained in the actual measurement, and the relationship between the one or more state quantities formulated and the one or more observed quantities. , A step of obtaining an estimate of one or more state quantities by performing Bayesian inference.
Based on the estimated value, the step of controlling the combustion of the combustion furnace and
A combustion control method for a combustion furnace, which comprises. A combustion control device configured to control combustion in a combustion furnace for combusting an object to be processed by estimating one or more state quantities that cannot be directly measured. And
A plurality of state quantities having one or more state quantities as explanatory variables and one or more observables that can be directly measured at one or more observation points arranged in the combustion furnace as objective variables. The simulation execution unit that executes the numerical simulation of
A formulation unit that formulates the relationship between the one or more state quantities and the one or more observables based on the execution results of the plurality of numerical simulations.
An observable input unit that receives the measured values of the one or more observations actually measured at the one or more observation points.
Based on the statistical information of the measured values of the one or more observed quantities obtained in the actual measurement, and the relationship between the one or more state quantities formulated and the one or more observed quantities. , A state quantity estimation unit that derives an estimated value of one or more state quantities by performing Bayesian estimation,
A control unit that controls the combustion of the combustion furnace based on the estimated value,
A combustion control device for a combustion furnace, characterized in that it is provided with. The combustion furnace is a stoker type incinerator, and the one or more state quantities are the supply amount of the object to be processed supplied on the grate of the stoker type incinerator, and the said amount staying on the grate. Retained amount, water content, combustible content, ash content, calorific value, and element composition of the object to be treated, and pyrolysis gas and / or generated by the thermal decomposition and / or combustion reaction of the object to be processed on the grate. The combustion control device for a combustion furnace according to claim 3, further comprising at least one of a combustion gas temperature and chemical composition. The combustion furnace is a fluidized bed incinerator, and the one or more state quantities are the supply amount of the object to be processed supplied in the fluidized bed of the fluidized bed incinerator, and stay in the fluidized bed. Moisture, combustibles, ash, calorific value, and elemental composition of the object to be treated, and thermal decomposition gas and / or generated by the thermal decomposition and / or combustion reaction of the object to be treated in the fluidized bed. The combustion control device for a combustion furnace according to claim 3, further comprising at least one of a combustion gas temperature and chemical composition. The chemical composition of the thermal decomposition gas and / or combustion gas includes hydrogen, carbon monoxide, carbon dioxide, methane, ethylene, oxygen, nitrogen, ammonia, hydrogen cyanide, nitrogen monoxide, nitrogen dioxide, dinitrogen monoxide, and hydrogen chloride. The combustion control device for a combustion furnace according to claim 4 or 5, wherein the combustion control device comprises at least one of the above. The one or more observation points stay on the grate of the stoker incinerator at the side wall and / or ceiling wall of the secondary combustion chamber arranged above the grate of the stoker incinerator. 4 or claim 4, characterized in that it is arranged higher than the surface of the object to be treated and lower than the supply position of the secondary combustion air and / or the recirculated exhaust gas supplied to the secondary combustion chamber. 6. The combustion control device for the combustion chamber according to 6. The one or more observation points are the fluidized bed interface of the fluidized bed incinerator at the side wall and / or ceiling wall of the secondary combustion chamber arranged above the fluidized bed portion of the fluidized bed incinerator. The combustion according to claim 5 or 6, characterized in that it is arranged at a higher position and lower than the supply position of the secondary combustion air and / or the recirculated exhaust gas supplied to the secondary combustion chamber. Combustion control device for the furnace. The 7 or 8 claim, wherein the one or more observables include the temperature of the in-fire gas and / or the chemical composition of the in-fire gas measured at the one or more observation points. The combustion control device of the combustion furnace described. The chemical composition of the gas in the furnace includes at least one of hydrogen, carbon monoxide, carbon dioxide, methane, ethylene, oxygen, nitrogen, ammonia, hydrogen cyanide, nitrogen monoxide, nitrogen dioxide, dinitrogen monoxide, and hydrogen chloride. The combustion control device for a combustion furnace according to claim 9, wherein the combustion control device includes one concentration. The control unit determines the feeding speed of the grate of the stoker-type incinerator, the supply speed of the object to be processed to the flow-bed incinerator, and the stoker-type incinerator based on the estimated values of the one or more state quantities. The flow rate of primary combustion air and / or recirculated exhaust gas supplied from the lower part of the grate of the incinerator or the lower part of the fluidized layer of the fluidized bed incinerator, and supplied to the secondary combustion chamber of the stoker incinerator or the fluidized bed incinerator. Flow rate of secondary combustion air and / or recirculated exhaust gas, flow rate of cooling water supplied into the incinerator to lower the temperature inside the stoker type incinerator or the fluidized bed type incinerator, the stoker type incinerator. Alternatively, any one of claims 4 to 10, characterized in that at least one of the flow rates of urea water or ammonia water supplied as a denitration reaction agent in the fluidized bed incinerator is adjusted. The incinerator combustion control device according to.

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