JP5452906B2 - Combustion control system for combustion furnace and combustion control method thereof - Google Patents

Description

  The present invention relates to a combustion control system for a combustion furnace and a combustion control method therefor, and more particularly to a technique suitable for combustion control in a refuse incinerator or the like.

  In recent years, in waste treatment facilities, the concentration of nitrogen oxides (NOx) in exhaust gas has been reduced and dioxins have been prevented to prevent environmental pollution, heat recovery has been made more efficient, and exhaust gas treatment equipment has been downsized. Many next-generation combustion methods have been proposed. In this next-generation combustion system, stable combustion control is required. Specifically, (i) stabilization of combustion heat, (ii) stable combustion at a target air ratio, (iii) dioxin and monoxide Suppression of carbon (CO) generation and NOx fluctuations are required.

When designing a combustion furnace, control targets such as dust thickness in the incinerator, temperature distribution in the furnace, O ₂ distribution, CO distribution, etc. are detected by various sensors, and are optimal for each control loop. The automatic combustion control of the stoker-type waste incinerator is mainly controlled by the boiler evaporation amount, and the stoker speed and combustion air amount are automatically controlled so that the controlled object is stabilized. Controlled.

  For example, a combustion control device illustrated in FIG. The reliability of combustion control is improved by accurately measuring the waste surface temperature, which is the representative temperature of the primary combustion unit 111, and the furnace temperature, which is the representative temperature of the secondary combustion unit 112, and performing combustion control, such as dioxins Hazardous gas can be reduced. Specifically, a waste surface temperature measuring device 220 that measures the waste surface temperature of the primary combustion unit 111 in the waste incinerator 100 via infrared rays, an in-furnace temperature sensor 210 that measures the in-furnace temperature, a waste surface temperature, and And a control device 300 that performs combustion control based on the furnace temperature (see, for example, Patent Document 1).

  Furthermore, in the waste treatment facility, the size of the waste supplied from the waste hopper and the calorific value are not constant, so the amount of evaporation is controlled by controlling the primary combustion air amount and the waste feed amount using the evaporation amount (converted evaporation amount) as an index. It was adjusted to be constant. At this time, the primary combustion air amount and the waste feed amount are controlled according to the position of the burn-off point in order to surely burn off the dust and prevent the unburned portion from being emitted. Further, in order to suppress the generation of CO due to the fluctuation of the combustion air amount, the secondary air amount is controlled so that the oxygen concentration at the furnace outlet becomes constant. Furthermore, in order to realize complete combustion (CO suppression) by blowing in secondary air, exhaust gas is recirculated by blowing exhaust gas from the furnace outlet into the furnace, and exhaust gas is drawn from the upper part of the combustion stoker after the furnace and blown into the furnace A reflux gas system was sometimes used.

JP 2003-106509 A

  However, the above prior art has the following problems. In other words, if the incinerator changes one operation amount, the effect affects many state quantities (boiler evaporation, combustion gas temperature, oxygen concentration in exhaust gas, etc.), and the causal relationship between the operation quantity and the state quantity is clarified. It is very difficult to convert. In particular, depending on the conditions in the furnace, it is often difficult to install measurement means to grasp the state quantity, and it is difficult to grasp the accurate state quantity, and it is not possible to set an appropriate manipulated variable. there were. In addition, it is required to uniformly stabilize a large number of state quantities. In recent years, automatic combustion control of stoker-type waste incinerators has become very sophisticated, and it is very difficult to understand and adjust automatic combustion control. It is becoming.

  In addition, static adjustment and dynamic adjustment of automatic combustion control for stoker-type waste incinerators has been performed by the coordinator operating the plant directly during combustion adjustment during the trial operation period. Therefore, sufficient time cannot be used for static adjustment and dynamic adjustment of automatic combustion control. In addition, because it is an adjustment within the risk of having a large direct impact on the actual plant operation, a normal operator deepens the understanding of the highly advanced automatic combustion control system by directly operating the plant. It is very difficult to learn adjustment technology. Here, “static adjustment” refers to the operation check of each device and control system that is performed after the combustion control device is installed and before the load operation (the implementation of the waste incineration process). Or pump operation check. “Dynamic adjustment” refers to the operation check of each device or control system performed before actual operation, and includes, for example, dried rice cake and soda boiled food.

  Therefore, there is a growing demand for process simulators for automatic control devices that can experience understanding of highly sophisticated automatic combustion control devices and improve adjustment technology offline without using actual plants. . In addition, if this is realized, it will play a major role in the development of a new automatic combustion control device configured with a PID auto-tuning function, a chaos theory, an automatic learning function, and the like.

  In view of the above-mentioned problems of the prior art, an object of the present invention is to construct an actual plant by simulation based on a combustion model, to deepen understanding of a highly advanced automatic combustion control device, to acquire adjustment technology, or It is an object of the present invention to provide a combustion control system and a combustion control method for a combustion furnace that can be applied to static adjustment and development of new automatic combustion control.

  As a result of extensive research, the present inventors have found that the above object can be achieved by the combustion control system and combustion control method for a combustion furnace described below, and have completed the present invention.

The present invention controls at least one of the quantity of combustion object to be introduced into the combustion furnace, the quality of the combustion object, the amount of air, the temperature of the air, and the stoker speed, and at least the temperature, gas concentration, gas in the furnace A combustion control system that controls a combustion state of the combustion furnace using any one of a flow direction, a gas flow rate, and an evaporation amount as a control index, and at least (a) a control mechanism related to each of the control objects to be controlled. (B) a measuring unit related to each control index from which process data is obtained; and (c) receiving the process data, and performing a simulation on a specific control index among the control indices from design conditions of the combustion furnace. And a simulation apparatus that creates boundary conditions for the specific control index as simulation data and transmits the simulation data, and (d) the simulation An automatic combustion control device that receives control data or this and the process data, calculates an operation amount related to the control object, and transmits a control signal to the control mechanism, and (e) the control mechanism and the automatic combustion controller, said measuring means and the simulation apparatus and automatic combustion control apparatus provided with a communicating means capable of communicating signals or data between the simulation device and the automatic combustion control device,
Simulation data created based on the process data is transmitted in the simulation apparatus, and the received operation amount is calculated in the automatic combustion control apparatus, and the operation amount is transferred to the simulation apparatus again. Then, an operation for calculating new simulation data and taking it into the automatic combustion control device again is performed. By repeating the operation, adjustment training including confirmation of operation of each device and control system before the load operation is performed in advance. It has a function of adjusting .

  According to the combustion control system having such a configuration, some of the process data such as the evaporation amount and the furnace temperature are obtained as control indices, the furnace combustion state is simulated in real time, and the optimum combustion state (design condition) is determined. It becomes possible to control the waste feed and the amount of combustion air necessary for forming. In particular, in a garbage incinerator where the quality (composition) and moisture content of the garbage changes from moment to moment, the changes in the combustion status of the furnace due to changes in the combustion state of the garbage are not a local point of view. By setting boundary conditions that approach the design conditions set by the combustion model while grasping the combustion state, it is possible to always perform optimum combustion control. At the same time, simulations based on these combustion models make it possible to build a real plant by simulation, which was difficult with conventional combustion control systems, deepening the understanding of highly advanced automatic combustion control devices, and adjusting technology It is possible to provide a combustion control system for a combustion furnace and a method for controlling the combustion that can be applied to the development of a new automatic combustion control.

In other words, in the conventional control system, the operation amount to be adjusted is set by comparing the information in the operating conditions (the operation amount in the controlled object and the process data on the control index) with the information in the corresponding design conditions. Therefore, as described above, it was not possible to perform control following the change in the waste quality or the change in the combustion state in the stoker. In the present invention, by setting the boundary condition Fo of the control index in an ideal combustion state from the installation conditions, the required specifications, or the design conditions, it is possible to clarify the standard of the optimum combustion control system of the actual machine. Next, a simulation is performed from the information in the actual operating conditions, and the boundary condition Fn or the distribution in the furnace Mn is created, thereby grasping the more accurate combustion state of the entire system rather than the partial information in the past. Can do. At this time, boundary conditions (simulation data) are performed for a plurality of specific control indexes, and the optimal combustion control for the entire system is performed by comparing and adjusting the ideal combustion state and the actual operation state for each control index. It can be performed. Further, based on process data such as the evaporation amount, simulation data such as a fuel cut-off point position is calculated by a simulation device. These simulation data are taken into the control unit (ACC), and the optimum operation amount such as the feed rate is calculated so that the boiler evaporation amount becomes the set value, and this operation amount is transferred to the simulation device again. The simulation is performed, new simulation data is calculated, and is again taken into the ACC. By repeating this process many times, it is possible to confirm the operation of ACC as if it were a real plant without operating the actual plant, and it can be applied to adjustment training and static adjustment (debugging work). it can.

  Here, the “boundary condition” means the optimum value or the optimum numerical range of the process data of the manipulated variable and the control index in the controlled object. For example, regarding the furnace temperature, the temperature in the primary combustion zone or the dust surface on the stoker In addition to the temperature of a specific part such as the temperature of the gas, the average temperature of a specific region including the specific part, the highest temperature part (distance from the wall surface) of the cross section of the secondary combustion zone, and a predetermined temperature (for example, 800 ° C.) The area of the specific region or the position of the boundary can be set as the boundary condition. In addition, “simulation data” refers to “simulation” here, that is, specific information (process data) that is a specific control index under actual operating conditions, so that a combustion state close to design conditions can be formed. This refers to the operation amount data and the process data of the control index at that time when the operation amount for the control target is set.

  Further, the present invention is the combustion control system for a combustion furnace, wherein the simulation device has a function of creating a combustion model based on the control object or / and the control index, and uses the combustion model. A simulation is performed, and simulation data is created in accordance with an instruction from the automatic combustion control device.

  Combustion furnace combustion control is determined by determining the specifications and functions of the combustion furnace, and the control target and / or control index (herein referred to as “element”) is determined, and each element is simplified and the correlation is set. can do. By clarifying these correlations, it is possible to create a so-called “combustion model”, and clarify the priority of combustion control, or the influence of other control elements on control operations. It is possible to perform a more accurate simulation using the combustion model. In the combustion control system according to the present invention, simulation data (boundary conditions) is not transmitted unilaterally from the simulation device, but the boundary conditions of the control index required in the automatic combustion control device are limited and instructed. By performing the simulation in real time based on the simulation data, combustion control corresponding to the current process data can be performed more quickly.

  Further, the present invention is a combustion control system for the combustion furnace, wherein the control system in the automatic combustion control device is a PID control system that performs stabilization control on instantaneous data, and an instantaneous data fluctuation amount. An autoregressive model control system that performs dynamic optimization control, and a fuzzy control system that performs steady-state return control on instantaneous data that deviates from a preset control range or its fluctuation amount .

  According to the combustion control system using the automatic combustion control device having such a configuration, combustion control according to the operating state of the actual plant becomes possible, and the automatic combustion control device of the operating state in the actual plant is combined with the above simulation device. Static adjustment (debugging work) is possible without operating the actual plant. In addition, by effectively connecting and using the functions of the PID control system, autoregressive model control system, and fuzzy control system, control in the optimal combustion state closer to the design conditions in the actual plant operating state Can do. At the same time, even in the actual operation state, the control in the optimum combustion state can be performed using real-time process data or boundary conditions as a control index.

In addition, the present invention controls at least one of the quantity of the combustion object to be introduced into the combustion furnace, the quality of the combustion object, the amount of air, the temperature of the air, and the stoker speed, and at least the temperature in the furnace and the gas concentration A combustion control method for controlling the combustion state of the combustion furnace using any one of a gas flow direction, a gas flow rate, and an evaporation amount as a control index, and the autoregressive model control which is a high-order control as the control system of the combustion furnace Alternatively, fuzzy control, which is a non-stationary control system, is incorporated, and the process data or simulation data related to the received control index is used to perform stabilization control on the instantaneous data based on the PID control system. The dynamic optimization control is performed based on the autoregressive model control system for the data fluctuation amount of the data, and the instantaneous data deviating from the preset control range or its fluctuation amount It performs steady return control based on fuzzy control system for, performs combustion control, the following steps
(S1) inputting a design condition of the combustion furnace in advance and setting a combustion model based on the control object or / and the control index;
(S2) setting a boundary condition Fo for a specific control index serving as a reference from the combustion model;
(S3) receiving and storing the process data;
(S4) performing a simulation on a specific control index among the control indices from the combustion model using the process data;
(S5) creating a boundary condition obtained by simulation as simulation data;
(S6) comparing a boundary condition Fn for a specific control index n out of the simulation data with the boundary condition Fo;
(S7) If there is a predetermined difference at the time of the comparison, the control target T1 to be controlled is specified so that the boundary condition Fn is close to the boundary condition Fo, and the operation amount is calculated;
(S8) controlling the operation amount for the control target T1, and
(S9) performing a simulation using the process data related to the control index n in the actual operating condition after the control operation, and creating a boundary condition Fn ′ as simulation data;
(S10) comparing the boundary condition Fn ′ with the boundary condition Fn;
(S11) If there is a predetermined difference at the time of the comparison, the control target T2 to be controlled is specified so that the boundary condition Fn ′ is close to the boundary condition Fn, and the operation amount is calculated; ,
(S12) controlling the operation amount for the control target T2, and
It is characterized by having .

By this combustion control method, it is possible to perform control in an optimal combustion state that is closer to the design conditions in the actual plant operation state, off-line from the actual plant. At the same time, even in the actual operation state, the control in the optimum combustion state can be performed using real-time process data or boundary conditions as a control index. In addition, in the control based on the ideal combustion state, it may be difficult to form a combustion state that reflects the actual operating condition in which inhomogeneous waste is introduced. By repeatedly repeating the setting of the distribution in the furnace, the boundary condition based on the process data under the actual operating conditions, and the setting of the distribution in the furnace, the optimum combustion control method in the actual operating state became possible. At this time, it is possible to restart the starting point of step (S4) or step (S9) by using the previous simulation result or the previous simulation result stored, and only the variation such as the boundary condition to be compared is changed. It is possible to shorten the processing time by performing re-simulation or resetting boundary conditions and distribution in the furnace.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. That is, a case where the combustion control system and the combustion control method of the combustion furnace according to the present invention are applied to, for example, combustion control of a stoker type incinerator will be described as one embodiment.

<Combustion control system for combustion furnace according to the present invention>
A combustion control system for a combustion furnace according to the present invention (hereinafter referred to as “the present combustion system”) is a waste (to be combusted) treated with respect to a stoker-type waste incinerator (corresponding to a combustion furnace, hereinafter referred to as “incinerator”). ) And auxiliary combustion air as inputs, and the amount of heat generated, exhaust gas and dust ash as outputs, and at least the amount of combustion objects to be input to the combustion furnace, the quality of combustion objects, the amount of air, Either the temperature or the stalker speed is controlled, and at least one of the temperature in the furnace, the gas concentration, the gas flow direction, the gas flow rate, and the evaporation amount is controlled as a control index.

At this time, the combustion system includes at least (a) a control mechanism related to a control target on which a control operation is performed, (b) measurement means related to each control index from which process data is obtained, and (c) receiving the process data. And a simulation device that performs a simulation for a specific control index among the control indices from the design conditions of the combustion furnace, creates a boundary condition for the specific control index as simulation data, and transmits the simulation data; d) an automatic combustion control device that receives the simulation data and / or process data, calculates an operation amount related to a control target, transmits a control signal to the control mechanism, and controls the control mechanism; and (e) control Mechanism and automatic combustion control device, measurement means and simulation device and automatic combustion control device, simulation And a communication means capable of communicating signals or data between the location and the automatic furnace.

[Composition of combustion furnace using this combustion system]
FIG. 1 shows a schematic overall configuration example of a combustion furnace using the present combustion system. The incinerator 10 provided with (a) a control mechanism (details will be described later) and (b) a measurement means (details will be described later) may include (c) a control device 20, (d) a simulation device 30 and (e) a communication means ( Predetermined control is performed in cooperation with the one-dot chain line portion in the figure. At this time, the control device 20 and the simulation device 30 may be constructed in a process simulator rather than in separate computers so that automatic combustion control (ACC) can be adjusted in one computer. Further, when the ACC of the existing combustion furnace has the same function as that of the control device 20, it is also possible to use the ACC of the actual plant and connect the ACC of the actual plant and the simulation device 30 according to the present invention. By doing so, static adjustment (debugging work) is possible without operating the actual plant.

  In the incinerator 10, a hopper 1 for storing waste and a stoker 3 for burning the waste are provided in the furnace body 2, and the waste in the hopper 1 is sent to the stocker 3 by the waste supply device 4. The stalker 3 is composed of a dry stalker 3A, a combustion stalker 3B, and a post-combustion stalker 3C, each of which is separately driven to reciprocate to feed garbage. The furnace body 2 includes a primary combustion zone 2A provided at the upper part of the stoker 3, a secondary combustion zone 2B at the upper part thereof, a primary combustion air supply device 5 for supplying air to the stoker 3 and the primary combustion zone 2A, A secondary combustion air supply device 6 for supplying secondary combustion air to the secondary combustion zone 2B, an ash discharge unit 7 for discharging dust ash, and an exhaust gas discharge unit 8 for discharging exhaust gas in the furnace are provided. The primary combustion air is supplied via the blower 5F, the primary air duct 5D, and the regulating valves 5A, 5B, 5C. The secondary combustion air is supplied through the blower 6F, the secondary air duct 6D, and the first, second, and third air nozzles 6A, 6B, and 6C.

Garbage thrown into the hopper 1 is primarily burned by the primary combustion air while being sent in the order of the dry stoker 3A, the combustion stoker 3B, and the post combustion stoker 3C. In the dry stoker 3A, garbage is mainly dried by the high-temperature combustion gas generated by the combustion in the subsequent combustion stoker 3B and the post-combustion stoker 3C, and partial combustion starts. The gas generated from the waste on the dry stoker 3A is water vapor due to evaporation of moisture, hydrocarbon gas generated by dry distillation, CO generated by incomplete combustion, carbon dioxide (CO ₂ ) by complete combustion, and the like. In the combustion stalker 3B, garbage is mainly combusted by the primary combustion air. The primary combustion air supplied to the combustion stoker 3B is an amount necessary and sufficient for the combustion of the waste, and the gas generated from the waste on the combustion stoker 3B contains a high concentration of NOx. In the post-combustion stoker 3C, the unburned portion in the incineration ash is burned out. In the secondary combustion zone 2B, secondary combustion air is supplied to the lower, middle, and upper portions thereof to completely burn the unburned or incompletely burned products from the primary combustion zone 2A. The dust ash generated by the combustion is discharged from the ash discharge unit 7, and the exhaust gas in the furnace is discharged from the exhaust gas discharge unit 8. At this time, CO, NOx, oxygen (O ₂ ), and the like in the exhaust gas are managed so as to be below a predetermined concentration.

[Components of the combustion system]
Next, the components of the combustion system will be described in detail with reference to FIGS. 1 and 2.

(A) Control mechanism As shown in FIG.
(A-1) Garbage supply device 4 for controlling and operating the input amount of garbage,
(A-2) A stalker driving device 3D for controlling the stalker speed.
(A-3) A blower 5F that is provided in the primary combustion air supply device 5 and that controls and operates the entire amount of primary combustion air, and an adjustment valve 5A that controls and operates each air amount so as to correspond to the stokers 3A, 3B, and 3C. 5B, 5C,
(A-4) The blower 6F that is provided in the secondary combustion air supply device 6 and controls and operates the entire amount of the secondary combustion air, and each air amount corresponding to the lower, middle, and upper portions of the secondary combustion zone 2B. Nozzles 6A, 6B, 6C to be controlled
(A-5) primary combustion air preheater 5E for controlling the temperature of the primary combustion air;
(A-6) Secondary combustion air preheater 6E for controlling the temperature of the secondary combustion air
Have In addition, although not shown, a primary combustion air damper driving device, a secondary combustion air damper driving device, a reflux gas fan driving device, or the like may be used as the control mechanism. Since the arrangement or supply amount of the combustion air supply greatly affects the distribution in the furnace, the primary / secondary combustion air amount balance and the primary combustion air regulating valves 5A, 5B, 5C and the first primary combustion air Therefore, it is necessary to appropriately control the balance between the arrangement of the second and third air nozzles 6A, 6B and 6C and the amount of air supplied therefrom. About arrangement | positioning, it sets so that an ideal combustion state may be formed from the design conditions of this combustion system, and air quantity is controlled and operated from the combustion state in actual operation conditions.

(B) Measuring means As shown in FIG.
(B-1) A dust input weight detection sensor 12 and a laser distance meter 13 are provided as sensor units for measuring the amount and quality of the dust charged into the hopper 1. The distance to the garbage surface is measured by the laser distance meter 13 to measure the volume of garbage to be charged. The garbage input weight detection sensor 12 measures the weight of the garbage. By detecting the volume and weight of the garbage, changes in the specific gravity of the garbage can be detected at predetermined time intervals. If you know the specific gravity of the garbage, you can predict the quality of the garbage to some extent.
(B-2) The sensor part which detects the combustion state in the incinerator 10 is provided. That is, for example, a NOx concentration meter 14, an O ₂ concentration meter 15, and a CO concentration meter 16 are provided in at least one of the secondary combustion zone 2B and the primary combustion zone 2A as sensor units for detecting process data relating to gas distribution. (FIG. 1 shows an example provided only in the secondary combustion zone 2B). Here, as the NOx concentration meter 14, the O ₂ concentration meter 15, and the CO concentration meter 16, a laser transmitter (not shown) irradiates the gas with laser light having a constant intensity while scanning the wavelength, and a laser receiver. A method of detecting the concentration and temperature of the gas by measuring the remaining laser beam by the above method may be adopted. Moreover, you may use the well-known sensor which detects the density | concentration of each gas. Further, in FIG. 1, a gas velocimeter 17 is provided in the primary combustion zone 2A, for example, as a sensor part relating to the gas flow direction, and an infrared radiation thermometer 18 is provided as the primary combustion as a sensor part for detecting process data relating to temperature distribution. It is provided in zone 2A. At the end of the combustion furnace 10, there is provided a steam flow meter 19 for detecting the flow rate of steam generated from dust as a sensor for measuring the amount of evaporation corresponding to the amount of energy accompanying combustion. As another sensor unit, a power generation amount detector or the like can be used. Each detection signal (detection information) from these sensor units is input to the control device 20 as process data.

(C) Control Device As shown in FIG. 2, the control device 20 transmits and receives a control signal to and from the control mechanism OP and simulation data (boundary conditions) with the simulation device 30, and from the simulation device 30. And an operation amount calculator 20B that calculates an operation amount for controlling the control mechanism OP based on the simulation data. If necessary, as shown in FIG. 2, a process data acquisition unit 20A that receives an output signal from the measuring means SE is provided, and an operation amount is calculated based on simulation data and / or process data. From the control device 20, the operation amount calculated in this way is transmitted to the control mechanism OP, and the control operation is performed. At this time, a plurality of control operations are performed, the process data related to the control index n in the actual operating condition after the primary control operation is compared with the boundary condition Fn, and if there is a predetermined difference, the control to be subjected to the secondary control operation It is preferable to perform control operations by specifying a target.

    At this time, as shown in FIG. 3, the control system is based on a PID control system that performs stabilization control on instantaneous data, and dynamic optimization control is performed on instantaneous data fluctuation as superordinate control. Auto-regression model control system (AR control system) that performs, and fuzzy control system that performs steady-state return control for instantaneous data that deviates from the preset control range or its fluctuation amount, and the functions of each control system It is preferable to use it effectively connected. It is possible to perform control in an optimal combustion state that is closer to the design conditions in the actual plant operating state, and at the same time, it is possible to perform real-time optimal combustion control in the actual operating state. In addition, it is preferable to use a modified method for arithmetic expressions and coefficients constituting each control system so as to match a result of a simulation test or a mounting test in the present combustion system, a previous in-core combustion performance, or the like. . Further, when the automatic combustion control (ACC) is adjusted using the simulation apparatus 30, the ACC is mainly configured by PID control, and optimal parameters (PID parameters, etc.) are required to realize stable combustion. ) Must be set. However, if one operation amount is changed in the waste incinerator, the effect will spread to many state quantities, and many state quantities (boiler evaporation, combustion gas temperature, exhaust gas oxygen concentration, etc.) will be uniformly stabilized. Therefore, it is very difficult to judge whether the combustion state is good or bad. Therefore, it is also preferable to determine whether the ACC adjustment is good or not by using combustion state determination using fuzzy reasoning in fuzzy control. If such a system is used, when developing a new automatic combustion control device composed of a PID auto-tuning function, a chaos theory, an automatic learning function, etc., it is possible to determine whether the control effect is right or wrong, Can support the development of automatic combustion control devices.

  Further, the operation amount calculation unit 20B is provided with a rule storage unit 20C that stores a “rule” for determining the operation amount. Based on the “rule”, the boundary condition Fo and the boundary condition Fn from the simulation device 30 are provided. The operation amount corresponding to the difference is calculated and the control mechanism OP is controlled. “Rules” stored in the rule storage unit 20C include calculation conditions and calculation formulas for determining the operation amount of the control target to be controlled. At this time, it is preferable to perform the following predetermined processing on the process data before calculation, and it is preferable to have such a processing function. Specifically, (c1) an average process for a predetermined time or a predetermined number of data, particularly a moving average process, and (c2) an upper value from data within a predetermined time or a predetermined number of data in order to remove so-called spike noise. In addition, it is possible to perform more accurate arithmetic processing by performing average processing of data that is averaged by deleting lower values and (c3) correction processing of time delay of other process data based on specific process data. it can.

(D) Simulation Device As shown in FIG. 2, the simulation device 30 includes a process data acquisition unit 30A that receives process data from the measurement means SE, a process data storage unit 30B, and a boundary that creates boundary conditions based on the combustion model. A condition setting unit 30C, a combustion model setting unit 30D, and a design condition setting unit 30E are provided. In the design condition setting unit 30E, an installation condition, a required specification, or a design condition for a combustion furnace for ensuring an optimum combustion condition is stored so as to be inputable. In the combustion model setting unit 30D, a combustion model is created based on such design conditions and the like. Details of the combustion model will be described later. At this time, similarly to the above (c), it is preferable to perform predetermined processes (c1) to (c3) on the process data before calculation, and it is preferable to have such a processing function.

  The boundary condition setting unit 30C stores calculation conditions, calculation expressions, and the like necessary for creating the boundary conditions. In addition, an operation amount or / and, for example, a required evaporation amount or a concentration of CO, NOx, or the like in exhaust gas that is subject to legal regulations is also stored. Using these arithmetic expressions and the like, simulation is performed based on the process data and the combustion model for the control index to create simulation data, and the boundary condition is created from the obtained simulation data. Specifically, the boundary condition in the ideal combustion state (design condition) based on the process data (including the manipulated variable related to the control target) about the combustion model and control index set from the design conditions of this combustion system Fo is calculated and created, and the boundary condition Fn is calculated and created from the process data regarding the operation amount or the control index related to the control target in the actual operation state. The created boundary condition Fo or Fn can be an output that constitutes part of the process data in the actual plant, similarly to the output from the measuring means SE that does not actually exist in the combustion furnace. At this time, the analysis means for the simulation is based on the multivariate analysis method or the autoregressive estimation method using the AR algorithm, the result of the simulation test or the mounting test in the present combustion system, the previous combustion results in the furnace, etc. It is preferable to use a modified method so as to meet the above. At this time, similarly to the above (c), it is preferable to perform predetermined processes (c1) to (c3) on the process data before calculation, and it is preferable to have such a processing function.

(E) Combustion state display device (not shown)
A combustion state display device (not shown) is provided for displaying simulation data. For example, by visualizing the distribution in the furnace (see FIG. 4) as will be described later, it is possible not only to determine the suitability of the combustion state based on the manipulated variable and the process data, but also to determine the suitability of the combustion state from the movement of the entire combustion furnace. Judgment can be made. This is useful when checking and checking work periodically at start-up or during actual operation. In addition, it is possible to review the arrangement of sensors and the overall control method of the combustion system from such a display.

The above components are combined to constitute, for example, the combustion system shown in FIG. Each component processes and manipulates a plurality of process data and operation amounts. Specifically, based on process data such as evaporation amount, quantity and quality of combustion object, gas concentration, gas flow rate, furnace temperature, etc., burnout point position, boiler evaporation amount, dust layer level, exhaust gas O ₂ concentration The simulation device 30 calculates simulation data such as the primary air amount, the secondary air amount, and the combustion chamber outlet temperature. These simulation data are taken into the control device (ACC) 20, and the operation amount such as the optimum feed speed, stoker speed, air damper opening and the like is calculated so that the boiler evaporation amount and the excess air ratio become set values. This combustion system is illustrated. Further, this manipulated variable is transferred again to the simulation apparatus 30 to perform simulation, and new simulation data is calculated and taken into the ACC again. By repeating this process many times, it is possible to confirm the operation of ACC as if it were a real plant without operating the actual plant, and it can be applied to adjustment training and static adjustment (debugging work). it can.

[Combustion model]
In this combustion system, the function of creating simulation data and setting boundary conditions Fo and Fn plays an important role. Here, it is preferable to create a combustion model based on the control object or / and the control index, and to create such a simulation and boundary conditions using the combustion model. In the present combustion system, various control objects and control indices (elements) as described above are involved. Therefore, by creating a so-called “combustion model” that simplifies each element and clarifies the correlation, the priority of combustion control or the effect on other elements by controlling the specific element is clarified. And a more accurate simulation can be performed using the combustion model. As the combustion model, for example, a boiler model, a combustion chamber model, a stoker model, and the like can be considered. Specifically, a “combustion model in a combustion simulation of a waste incinerator” as exemplified in FIG. be able to. Focusing on the “combustion reaction model”, the “mass transfer model” that mainly models the mass balance and the related “gas state model” and “dust ash model”, and the “energy transfer” that mainly models the energy balance The “model” and the related “radiation / heat transfer model” are interconnected to form a combustion model. Further, by utilizing this, as illustrated in FIG. 5B, the control target in the combustion system (the parentheses indicate the control indexes related thereto) can be systematically represented.

  Furthermore, another combustion model in the combustion furnace using this combustion system is illustrated in FIG. The range of simulation data includes the ventilation system of the air / exhaust gas line, the boiler system of the boiler feed water / condensate line, and the combustion system that mainly transfers and burns garbage. Such a combustion model was constructed using a physical model method based on the conservation equations of mass, momentum, and energy in units of equipment. That is, in the combustion furnace, there are a plurality of devices such as a blower, a flow rate adjusting damper, a boiler facility, a combustion chamber, a dust supply device, and a stoker, and these are related to constitute a plant. Therefore, by configuring the combustion model in units of these devices, the control content for each device is clarified and the control content of the entire control system is clarified, so that an optimal control system can be applied. In addition, in order to realize the dynamic characteristics peculiar to the waste incinerator, an equipment model with an empirical rule added to the physical model is adopted, and each actual plant's unique data is adjusted by adjusting the operation data of each actual plant. It is also possible to reproduce the combustion characteristics.

<Combustion control method for combustion furnace>
FIG. 7 is a flowchart showing a processing example of the combustion control system. Based on this flowchart, a processing method (combustion furnace combustion control method, hereinafter referred to as “the combustion method”) by the combustion control system will be described. First, the combustion control system is activated to form a state in which each of the incinerator 10, the control device 20, and the simulation device 30 functions, and the treatment process takes a waste incinerator as a specific example, and the following step (S1) in advance Inputting a design condition of the combustion furnace, and setting a combustion model based on the control object or / and control index;
(S2) setting a boundary condition Fo for a specific control index serving as a reference from the combustion model;
(S3) receiving and storing process data relating to the control index;
(S4) performing a simulation on a specific control index among the control indices from the combustion model using the process data;
(S5) creating a boundary condition obtained by simulation as simulation data;
(S6) comparing a boundary condition Fn for a specific control index n out of the simulation data with the boundary condition Fo;
(S7) If there is a predetermined difference at the time of the comparison, the control target T1 to be controlled is specified so that the boundary condition Fn is close to the boundary condition Fo, and the operation amount is calculated;
(S8) controlling the operation amount for the control target T1, and
(S9) performing a simulation using the process data related to the control index n in the actual operating condition after the control operation, and creating a boundary condition Fn ′ as simulation data;
(S10) comparing the boundary condition Fn ′ with the boundary condition Fn;
(S11) If there is a predetermined difference at the time of the comparison, the control target T2 to be controlled is specified so that the boundary condition Fn ′ is close to the boundary condition Fn, and the operation amount is calculated; ,
(S12) controlling the operation amount for the control target T2, and
Consists of.

  In the above combustion control method, steps (S4) to (S7) are repeated based on the manipulated variable of the control target T1 set in step (S7) to eliminate a predetermined difference in the control index, and It is preferable to repeat the steps (S9) to (S12) based on the operation amount of the control target T2 set in step (S11) and to eliminate a predetermined difference regarding the control index. As described above, in the control based on the ideal combustion state, it may be difficult to form a combustion state that reflects the actual operating condition in which inhomogeneous waste is thrown in. By comparison with the ideal combustion state at the time of simulation By repeatedly setting the boundary conditions and distribution in the furnace, and the boundary conditions and distribution in the furnace based on the process data in the actual operating conditions, the optimum combustion control method in actual operating conditions has become possible. . At this time, it is possible to restart the starting point of step (S4) or step (S9) by using the previous simulation result or the previous simulation result stored, and only the variation such as the boundary condition to be compared is changed. It is possible to shorten the processing time by performing re-simulation or resetting boundary conditions and distribution in the furnace.

As described above, the following excellent technical effects can be obtained by using the combustion control method and the combustion control system according to the present invention.
(I) The automatic combustion control can be understood and operated / adjusted (parameter setting) training can be performed without operating the actual plant.
(Ii) The automatic combustion control can be statically adjusted (debugging work) without operating the actual plant.
(Iii) Development of automatic combustion control can be supported without operating an actual plant.

The combustion furnace to which the combustion control method and the combustion control system according to the present invention can be applied is not limited to an incinerator, and may be an electric ash melting furnace, a gasification melting furnace, or the like. In this case, examples of the process data acquired by the electric ash melting furnace include ash supply, slag flow, distance between electrodes, temperature distribution, O ₂ distribution, CO distribution, NOx distribution, gas flow direction, gas flow rate, and the like. Examples of process data acquired by the gasification melting furnace include temperature distribution, O ₂ distribution, CO distribution, NOx distribution, gas flow direction, gas flow velocity, and the like. Moreover, although the automatic combustion control apparatus of the stoker type | mold waste incinerator is made into the structural example above, waste incinerators other than the stoker type, an electric ash melting furnace, a gasification melting furnace, etc. may be used.

Explanatory drawing which shows the schematic whole structure of the combustion control system which concerns on this invention Schematic block diagram showing an example of a combustion control system according to the present invention Explanatory drawing illustrating the configuration of the control system of the combustion control system according to the present invention Explanatory drawing illustrating the components, control indices, etc. of the combustion control system according to the present invention Explanatory drawing illustrating a combustion model in the combustion control system according to the present invention Explanatory drawing illustrating another combustion model in a combustion furnace using this combustion system Flow chart showing a processing example of a combustion control system Explanatory drawing which shows the structural example of the combustion control apparatus which concerns on a prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hopper 2 Furnace main body 2A Primary combustion zone 2B Secondary combustion zone 3 Stoker 3A Dry stalker 3B Combustion stalker 3C Post combustion stalker 3D Stoker drive device 4 Waste supply device 5 Primary combustion air supply device 5A, 5B, 5C Regulating valve 5D Primary air Duct 5E Primary combustion air preheaters 5F, 6F Blower 6 Secondary combustion air supply device 6A First air nozzle 6B Second air nozzle 6C Third air nozzle 6D Secondary air duct 6E Secondary combustion air preheater 7 Ash discharge section 8 Exhaust gas discharge unit 10 Combustion furnace 12 Waste input weight detection sensor 13 Laser distance meter 14 NOx concentration meter 15 O ₂ concentration meter 16 CO concentration meter 17 Gas flow meter 18 Infrared radiation thermometer 19 Steam flow meter 20 Controller 20A Process data acquisition unit 20B Operation amount calculation unit 20C Rule storage unit 30 Simulation device 30A Process Over data acquisition unit 30B processes the data storing unit 30C boundary condition setting section 30D combustion model setting unit 30E design condition setting unit OP control mechanism SE measuring means

Claims (4)

At least one of the quantity of the combustion object to be input to the combustion furnace, the quality of the combustion object, the amount of air, the temperature of the air, and the stoker speed is controlled, and at least the temperature in the furnace, gas concentration, gas flow direction, gas A combustion control system that controls the combustion state of the combustion furnace using either the flow velocity or the evaporation amount as a control index, and at least (a) a control mechanism related to each of the controlled objects on which a control operation is performed, and (b) (C) receiving the process data, simulating a specific control index among the control indices from the design conditions of the combustion furnace, and (D) the simulation device that creates boundary conditions for the control index of the simulation index as simulation data and transmits the simulation data; An automatic combustion control device that receives the data or the process data and the process data, calculates an operation amount related to the control target, and transmits a control signal to the control mechanism, and (e) the control mechanism and automatic combustion control device, wherein the measuring means and the simulation apparatus and automatic combustion control apparatus provided with a communicating means capable of communicating signals or data between the simulation device and the automatic combustion control device,
Simulation data created based on the process data is transmitted in the simulation apparatus, and the received operation amount is calculated in the automatic combustion control apparatus, and the operation amount is transferred to the simulation apparatus again. Then, an operation for calculating new simulation data and taking it into the automatic combustion control device again is performed. By repeating the operation, adjustment training including confirmation of operation of each device and control system before the load operation is performed in advance. A combustion control system for a combustion furnace having a function of performing adjustment .   The simulation device has a function of creating a combustion model based on the control target or / and the control index, performs a simulation using the combustion model, and performs simulation data in accordance with instructions from the automatic combustion control device. The combustion control system for a combustion furnace according to claim 1, wherein the combustion control system is prepared.   As a control system in the automatic combustion control device, a PID control system that performs stabilization control on instantaneous data, an autoregressive model control system that performs dynamic optimization control on instantaneous data fluctuation, and a preset A combustion control system for a combustion furnace according to claim 1 or 2, further comprising a fuzzy control system that performs steady-state return control on instantaneous data that deviates from the controlled range or a fluctuation amount thereof. At least one of the quantity of the combustion object to be input to the combustion furnace, the quality of the combustion object, the amount of air, the temperature of the air, and the stoker speed is controlled, and at least the temperature in the furnace, gas concentration, gas flow direction, gas A combustion control method for controlling a combustion state of the combustion furnace using either a flow rate or an evaporation amount as a control index, wherein the control system of the combustion furnace is an autoregressive model control or / and unsteady control which is a high-order control System fuzzy control is incorporated, process control or simulation data related to the received control index is used, and stabilization control is performed on instantaneous data based on the PID control system, and instantaneous data fluctuations are controlled. The dynamic optimization control is performed based on the autoregressive model control system, and the fuzzy is applied to the instantaneous data that deviates from the preset control range or its fluctuation amount. It performs steady return control based on your system, performs combustion control,
The following steps
(S1) inputting a design condition of the combustion furnace in advance and setting a combustion model based on the control object or / and the control index;
(S2) setting a boundary condition Fo for a specific control index serving as a reference from the combustion model;
(S3) receiving and storing the process data;
(S4) performing a simulation on a specific control index among the control indices from the combustion model using the process data;
(S5) creating a boundary condition obtained by simulation as simulation data;
(S6) comparing a boundary condition Fn for a specific control index n out of the simulation data with the boundary condition Fo;
(S7) If there is a predetermined difference at the time of the comparison, the control target T1 to be controlled is specified so that the boundary condition Fn is close to the boundary condition Fo, and the operation amount is calculated;
(S8) controlling the operation amount for the control target T1, and
(S9) performing a simulation using the process data related to the control index n in the actual operating condition after the control operation, and creating a boundary condition Fn ′ as simulation data;
(S10) comparing the boundary condition Fn ′ with the boundary condition Fn;
(S11) If there is a predetermined difference at the time of the comparison, the control target T2 to be controlled is specified so that the boundary condition Fn ′ is close to the boundary condition Fn, and the operation amount is calculated; ,
(S12) controlling the operation amount for the control target T2, and
Combustion control method for a combustion furnace, characterized in that <br/> with.

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