Control device, waste incineration facility, control method and program

Abstract

To provide a controller capable of suppressing fluctuation of combustion in a garbage incineration facility.SOLUTION: A controller comprises a data acquiring unit that acquires a measured value measured by a sensor provided in a garbage incineration facility, a combustion speed estimating unit that estimates a combustion speed in an incinerator of the garbage incineration facility using the measured value, and a controller that controls the feed amount of garbage or the flow rate of combustion air, being fed into the incinerator.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a control device for a waste incineration facility, a waste incineration facility, a control method, and a program. [Background technology]

[0002] Waste-to-energy, which involves installing a boiler at a waste incineration facility, recovering the heat generated during waste incineration, and using the steam generated to generate electricity, is economically important because it adds value to waste as a fuel rather than simply treating it as waste.The most effective way to increase the added value of waste as a fuel is to stabilize the amount of steam generated and enable power generation as planned.

[0003] Generally, incinerators that incinerate municipal waste, industrial waste, etc. are equipped with a hopper, and waste is picked up by a crane and thrown into the hopper. The waste in the hopper is fed through a chute and then fed to the incinerator by a dust feeder located below the hopper. There are various types of dust feeders, but the most commonly used are pusher-type devices that push waste toward the incinerator by reciprocating motion. The pusher is located below the hopper and chute, and when the pusher extends, it pushes the waste around it into the incinerator. The pusher has a limited stroke, and when it extends to its full extent, it cannot push any more waste out. For this reason, after the pusher extends to its full extent, it retracts once and then extends again.

[0004] There are various types of pusher-type systems for supplying waste to an incinerator. For example, Patent Document 1 discloses a control method for adjusting the amount of waste supplied to an incinerator per unit time by the number of reciprocating movements of the pusher per unit time. In the control method described in Patent Document 1, the number of reciprocating movements of the pusher per unit time is increased or decreased according to the fluctuation in the moisture content of the waste, thereby suppressing the fluctuation in the steam flow rate. The steam flow rate has the property of fluctuating according to the heat value per volume of the waste supplied. The method in Patent Document 1 focuses on the moisture content of the waste as a cause of fluctuation in the heat value, but moisture is not the only factor that actually changes the heat value. For example, the synthetic resin content of the waste affects the heat value in the same way as moisture.

[0005] In addition, the method of Patent Document 1 requires a sensor for measuring moisture. Furthermore, in the case of the method of Patent Document 1, when waste containing a large amount of moisture is detected, feedforward compensation is performed by predicting the increase or decrease in combustion activity that occurs when the waste is fed to the incinerator. However, since it is not possible to accurately manage the time from when moisture is detected until the waste is actually fed to the incinerator, there is an error in the feedforward compensation.

[0006] Patent Document 2 discloses a method for controlling the combustion of waste, which calculates an estimated calorific value per unit of waste. In the case of the combustion control method of Patent Document 2, the boiler evaporation amount is calculated based on an estimate of the calorific value per unit of waste supply. However, as described below, several hours of data are required to estimate the calorific value per unit of waste supply, and the estimated value is an average value over several hours, so that the current "calorific value per unit of waste per hour" cannot be estimated in a timely manner, especially when the nature of the waste fluctuates over time. For this reason, the estimated boiler evaporation amount used to adjust the waste feed and primary combustion air is inaccurate, and fluctuations in the boiler evaporation amount are unavoidable. In addition, Patent Document 3 describes in paragraph 0013 that the waste is assumed to be composed of moisture, combustibles, and ash, and that the ash ratio and the composition ratio of the combustible components of the waste are constant, and only the lower calorific value of the combustibles is calculated based on a long-term material balance, and the other necessary process values ​​are calculated using average values ​​of several minutes to about 60 minutes to calculate the material and heat balance, thereby estimating the lower calorific value of the waste. However, it is difficult to estimate the higher or lower heating value in a short time, such as one minute. The lower and higher heating values ​​are the calorific values ​​per unit mass [J / kg], and are calculated in principle for the supplied waste using the following formula (1). The following explanation is common to both the lower and higher heating values, so it will be generalized to the lower heating value.

[0007]

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[0008] The denominator of formula (1) is the mass [kg] of the waste supplied between time t1 and time t2. The numerator represents the calorific value [J] of the waste supplied between time t1 and time t2. The integral interval of the denominator, the time difference between the start point t1 and the end point t2, may be, for example, one minute or less. However, the integral interval of the numerator, the time difference between the start point t1 and the end point t3, cannot necessarily be treated in this way. Pulverized coal, oil, and combustible gas burn up immediately after being supplied to the furnace, so the end point t3 of the integral interval of the numerator can be about the same as the end point t2 of the integral interval of the denominator, and therefore the lower calorific value can be calculated without delay, for example, within one minute. If it burns up immediately after being supplied, it is not important to distinguish when the heat was generated by the waste supplied in the calculation of the numerator, so it is permissible to simply set t3 = t2 and take the total heat generated from time t1 to time t2 as the heat generated by the waste supplied at the same time. However, unlike pulverized coal, waste takes more than an hour to burn out, so t3, the end point of the calorific value integration, must be at least an hour longer than t2. For this reason, long-term data covering at least the time until the waste is burned out (for example, about an hour) is required to calculate the numerator in equation (1). However, the calculation only reveals the lower calorific value of the waste that was supplied one hour ago. Even if the lower calorific value from an hour ago were known, it would not be of much use in real-time control.

[0009] In reality, the delay is not only one hour. The time delay will be explained below. The calorific value from time t1 to time t3 includes the calorific value of the waste that was supplied before time t1 and is already in the furnace, and the calorific value of the waste supplied after time t2. Therefore, in the calculation of the numerator of formula (1), only the heat generated by the waste supplied between time t1 and time t2 must be calculated separately from the heat generated by the waste, but this is difficult. Therefore, if the calorific value is simply integrated, the calorific value in the denominator is the total calorific value from time t1 to time t3, while the supply amount in the numerator is limited to the supply amount from time t1 to t2, so the low calorific value will be excessive. For example, if t1=0, t2=1 minute, it takes 60 minutes to burn out, and t3=61 minutes, if the calorific value is simply integrated, the low calorific value will be about 60 times the actual value. To prevent this, it is effective to lengthen the integration interval of the denominator by several times the time it takes for the waste to burn out, and to bring the values ​​of t2 and t3 closer together. For example, if t1=0, t2=300 minutes, and t3=360 minutes, the lower heating value is 1.2 times the actual value, which may be a good approximation. However, the lower heating value obtained by this method is delayed further in time and is an average of the heating value over a long period of time, not a timely heating value at each moment. In this way, the estimated lower heating value is, in principle, delayed and averaged by several hours, so it is not useful for operating operations when the combustion state suddenly changes. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2019-178850 A [Patent Document 2] Patent No. 5996762 [Patent Document 3] Patent No. 3822328 [Patent Document 4] Japanese Utility Model Application Publication No. 63-61621 Summary of the Invention [Problem to be solved by the invention]

[0011] A control method is provided for detecting fluctuations in combustion in a waste incinerator at an early stage and suppressing the fluctuations.

[0012] The present disclosure provides a control device, a waste incineration facility, a control method, and a program that can solve the above problems. [Means for solving the problem]

[0013] The control device disclosed herein includes a data acquisition unit that acquires measurement values ​​measured by a sensor equipped in a waste incineration facility, a combustion rate estimation unit that estimates a combustion rate in an incinerator of the waste incineration facility using the measurement values, and a control unit that controls the amount of waste supplied or the flow rate of combustion air supplied to the incinerator based on the combustion rate. The burning rate estimation unit estimates the burning rate by multiplying the measurement value by a maximum singular vector corresponding to a maximum singular value obtained by singular value decomposition of a variance-covariance matrix of the measurement value used for estimating the burning rate.

[0014] The control method of the present disclosure includes the steps of: acquiring a measurement value measured by a sensor provided in the waste incineration facility; estimating a combustion rate in an incinerator of the waste incineration facility using the measurement value; and controlling the amount of waste supplied or the flow rate of combustion air supplied to the incinerator based on the combustion rate. In the step of estimating the burning speed, the burning speed is estimated by multiplying the measured value by a maximum singular vector corresponding to a maximum singular value obtained by singular value decomposition of a variance-covariance matrix of the measured value used for estimating the burning speed.

[0015] In addition, the waste incineration equipment disclosed herein includes an incinerator for incinerating waste, a dust feeding device for supplying waste to the incinerator, a blower for supplying combustion air to the incinerator, a combustion air valve for controlling the flow rate of combustion air supplied from the blower to the incinerator, and the above-mentioned control device.

[0016] The program of the present disclosure includes a step of causing a computer to acquire measurement values ​​measured by a sensor equipped in a waste incineration facility, a step of estimating a combustion rate in an incinerator of the waste incineration facility using the measurement values, and a step of controlling an amount of waste supplied or a flow rate of combustion air supplied to the incinerator based on the combustion rate. In the step of estimating the burning speed, a process of estimating the burning speed by multiplying the measured value by a maximum singular vector corresponding to a maximum singular value obtained by singular value decomposition of a variance-covariance matrix of the measured value used for estimating the burning speed Execute the command. Effect of the Invention

[0017] According to the above-mentioned control device, waste incineration facility, control method and program, fluctuations in combustion in the waste incineration facility can be suppressed. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram showing an example of a waste incineration facility according to each embodiment. [Diagram 2] 2 is a diagram illustrating an example of a functional configuration of a main part of a control device according to the first embodiment; FIG. [Diagram 3] FIG. 4 is a diagram illustrating an example of an operation of the control device according to the first embodiment. [Figure 4] FIG. 11 is a diagram illustrating an example of a functional configuration of a main part of a control device according to a second embodiment. [Diagram 5] FIG. 11 is a diagram illustrating an example of an operation of the control device according to the second embodiment. [Figure 6] FIG. 11 is a diagram illustrating an example of a functional configuration of a main part of a control device according to a third embodiment. [Figure 7] FIG. 11 is a diagram illustrating an example of an operation of the control device according to the third embodiment. [Figure 8] FIG. 13 is a diagram illustrating an example of a functional configuration of a main part of a control device according to a fourth embodiment. [Figure 9] FIG. 13 is a diagram illustrating an example of a functional configuration of a main part of a control device according to a fifth embodiment. [Figure 10] FIG. 13 is a diagram illustrating an example of an operation of the control device according to the fifth embodiment. [Figure 11] FIG. 13 is a diagram illustrating an example of a functional configuration of a main part of a control device according to a sixth embodiment. [Figure 12] FIG. 13 is a diagram illustrating an example of the operation of the control device according to the sixth embodiment. [Figure 13] FIG. 2 is a diagram illustrating an example of a hardware configuration of a control device according to each embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, a waste incineration facility according to an embodiment will be described with reference to the drawings. In the following description, components having the same or similar functions are given the same reference numerals. Furthermore, duplicated descriptions of those components may be omitted. "XX or YY" is not limited to either XX or YY, but may include both XX and YY. This also applies when there are three or more selective elements. "XX" and "YY" are any element (e.g., any information).

[0020] (System Configuration) FIG. 1 is a diagram showing an example of a waste incineration facility according to each embodiment. The waste incineration facility 100 comprises a hopper 1 into which waste is fed, a chute 2 that guides the waste fed into the hopper 1 to the bottom, a pusher 10 that feeds the waste fed through the chute 2 into a combustion chamber 6, a grate 3 that receives the waste fed by the pusher 10 and dries and burns the waste while transporting it, a combustion chamber 6 in which the waste is burned, an ash outlet 7 that discharges ash, a blower 4 that supplies air, a number of wind boxes 5A-5E that guide the air supplied by the blower 4 to various parts of the grate 3, a pipeline 14 that supplies the air supplied by the blower 4 directly to the combustion chamber 6, and a boiler 9.

[0021] The pusher 10 is a dust feeder that moves in the direction of the arrow α to push out the garbage supplied through the chute 2, thereby supplying the garbage to the grate 3. The grate 3 is provided at the bottom of the chute 2 and the combustion chamber 6 and transports the garbage. The grate 3 is provided with a drying area 3A that evaporates moisture from the garbage supplied by the pusher 10 to dry it, a combustion area 3B located downstream of the drying area 3A to burn the dried garbage, and a post-combustion area 3C located downstream of the combustion area 3B to burn unburned components such as fixed carbon that pass through without being burned until they turn into ash. The operating speed of the grate 3 is controlled by receiving a control signal from the control device 20.

[0022] The blower 4 is provided below the grate 3 and supplies air to each part of the grate 3 through the wind boxes 5A-5E. A duct 8F that guides the air sent from the blower 4 to the wind boxes 5A-5E is connected to branch pipes that connect the duct 8F to each of the wind boxes 5A-5E, and the branch pipes are provided with valves 8A-8E, respectively, and the flow rate of the combustion air supplied to the wind boxes 5A-5E can be adjusted by adjusting the opening of the valves 8A-8E. The blowing amount of the blower 4 and the opening of the valves 8A-8E are controlled by receiving a control signal from the control device 20. The valves 8A-8E may be collectively referred to as primary combustion air valves.

[0023] The combustion chamber 6 is composed of a primary combustion chamber 6A and a secondary combustion chamber 6B above the grate 3, and the boiler 9 is disposed downstream of the combustion chamber 6. The primary combustion chamber 6A is disposed above the grate 3, and the secondary combustion chamber 6B is disposed further above the primary combustion chamber 6A. In the primary combustion chamber 6A, pyrolysis gas generated from the garbage is burned, and the unburned pyrolysis gas remaining in the primary combustion chamber 6A is sent to the secondary combustion chamber 6B, where it is mixed with secondary combustion air and the unburned components are also burned. A pipe 14 connecting the blower 4 and the secondary combustion chamber 6B is connected to the secondary combustion chamber 6B of the combustion chamber 6, and air can be supplied to the combustion chamber 6 by opening and closing a valve 14A provided in the pipe 14. The opening degree of the valve 14A is controlled by receiving a control signal from the control device 20. The valve 14A may be described as a secondary combustion air valve. The boiler 9 generates steam by exchanging heat between the exhaust gas sent from the combustion chamber 6 and water circulating inside the boiler 9. The steam is supplied to a power generating turbine (not shown) through a pipe 13. A steam flow sensor 11 that detects the flow rate of the steam is provided in the pipe 13. The steam flow sensor 11 is connected to a control device 20, and the measurement value measured by the steam flow sensor 11 is transmitted to the control device 20.

[0024] A flue 12 is connected to the exhaust gas outlet of the boiler 9, and the exhaust gas from which heat has been recovered in the boiler 9 passes through the flue 12 and an exhaust gas treatment facility (not shown) before being discharged to the outside.

[0025] The flue 12 is provided with an oxygen concentration sensor 15 for detecting the oxygen concentration of the exhaust gas. The oxygen concentration sensor 15 is connected to the control device 20, and the measurement value measured by the oxygen concentration sensor 15 is transmitted to the control device 20. The second pass of the boiler is provided with a temperature sensor 17A for measuring the temperature of the second pass, and the flue 12 is provided with a CO concentration sensor 17B for measuring the CO concentration of the exhaust gas and a NOx concentration sensor 17C for detecting the NOx concentration of the exhaust gas. Each of these sensors 17A to 17C is connected to the control device 20, and the measurement values ​​measured by the sensors 17A to 17C are transmitted to the control device 20. In addition, the pipe 8F is provided with a flow rate sensor 17D for detecting the flow rate of the primary combustion air supplied to the primary combustion chamber 6A through the wind boxes 5A to 5E, and the pipe 14 is provided with a flow rate sensor 17E for detecting the flow rate of the secondary combustion air supplied to the secondary combustion chamber 6B. These sensors 17D-17E are connected to a control device 20, and values ​​measured by the flow rate sensors 17D-17E are transmitted to the control device 20. A temperature sensor 16 that measures the temperature inside the combustion chamber 6 is provided in the combustion chamber 6. The temperature sensor 16 is connected to the control device 20, and values ​​measured by the temperature sensor 16 are transmitted to the control device 20. These sensors are provided in a typical waste incineration energy plant.

[0026] The control device 20 includes a data acquisition unit 21, a combustion rate estimation unit 22, a control unit 23, and a memory unit 24. The data acquiring unit 21 acquires various data such as the measurement values ​​measured by the sensors 11, 15, 16, 17A to 17D, user instruction values, etc. For example, the data acquiring unit 21 acquires the measurement value of the steam flow rate measured by the steam flow rate sensor 11.

[0027] The combustion rate estimation unit 22 calculates the combustion rate of the waste in the combustion chamber 6 (hereinafter, sometimes referred to as the furnace). As disclosed in Patent Document 4, the heat generation rate in the furnace decreases due to the following conflicting causes: (a) when the amount of waste to be burned in the furnace decreases (shortage of fuel), and (b) when the flames are put out by the supplied waste (excess fuel). When the heat generation rate decreases, the steam flow rate measured by the steam flow sensor 11 also decreases, so the decrease in the steam flow rate is also due to the conflicting causes (a) and (b). In conventional combustion control, in order to compensate for the fuel shortage of (a), if the cause is (b), the waste supply continues continuously, which may further decrease the heat generation rate (inverse response). Therefore, in conventional plants, if the decrease in heat generation rate continues for a certain period of time, an alarm is issued, and the operator takes measures such as estimating the cause and performing a recovery operation to eliminate the cause. In contrast, in the present disclosure, the combustion rate estimation unit 22 estimates the difficulty of burning the waste in the entire furnace, that is, the combustion per unit time that occurs in the furnace, in other words, the combustion rate, in real time based on "existing" sensors (steam flow rate sensor 11, temperature sensor 16, oxygen concentration sensor 15, respectively) such as the steam flow rate, the combustion chamber temperature, and the oxygen concentration in the exhaust gas, and uses the estimated combustion rate to calculate the supply amount of combustion air and the supply amount of waste. As will be described later, in the control of the waste supply amount in the present disclosure, the waste supply amount is determined so as to suppress the fluctuation of the steam flow rate by feedback control. At that time, the setting value of the feedback controller that commands the waste supply amount is adapted to the estimated combustion rate. Specifically, for example, if the waste is difficult to burn (the combustion rate is low), this corresponds to (b), so the feedback gain is lowered to avoid excessive supply. Otherwise, this corresponds to (a), so the feedback gain is set to the normal value. This makes it possible to appropriately deal with the decrease in the heat generation amount in each of (a) and (b).

[0028] In order to make the estimated result of the combustion rate function as intended, it is important to estimate the combustion rate of the garbage as quickly as possible. As explained with reference to Patent Documents 2 and 3, there is a fundamental problem in estimating the calorific value (lower calorific value) per unit supply of garbage. Therefore, in this disclosure, the combustion rate is used as an index instead of the lower calorific value. While the lower calorific value is the calorific value per unit mass of the garbage supplied, the combustion rate represents the heat generated by the entire furnace, regardless of the mass of the garbage in the furnace. In addition, the combustion rate includes not only the combustion of the garbage in the furnace but also the combustion of the pyrolysis gas. As mentioned above, in the garbage incineration facility 100, it takes time for the garbage to be burned after being fed, so a large amount of garbage accumulates in the furnace. The combustion rate of the accumulation is approximately constant as a whole furnace, but varies over time, and the result is the fluctuation of the steam flow rate measured by the steam flow sensor 11. Fluctuations in the combustion rate have a variety of causes, such as newly supplied garbage containing a lot of moisture, which hinders the combustion of the surrounding area, or changes in the supply of combustion air due to the collapse of the garbage layer, etc. Fluctuations in the combustion rate are also reflected in the measured values ​​of the garbage incineration facility 100 (such as the above-mentioned combustion chamber temperature and oxygen concentration in the exhaust gas) in addition to the steam flow rate. In this disclosure, the combustion rate in the furnace is estimated in real time from the measured values ​​obtained by existing sensors.

[0029] (Procedure for estimating burning rate) In the waste incineration facility 100, it is unavoidable that the combustion speed of the waste constantly fluctuates. In the waste incineration facility 100, although some of the supplied waste may burn instantly, most of it accumulates as combustible material on the furnace grate 3, and the dried parts burn in order. For example, suppose there is a lump of dried waste, and its surface is burning. At that time, if the grate 3 moves, etc., and the lump of waste breaks, and a new surface is generated that comes into contact with the combustion air, combustion will start anew from there, and the combustion speed of the entire furnace will increase. Conversely, if the surface is covered with waste containing a lot of moisture and the temperature drops, or if the supply of combustion air is cut off, combustion will be hindered and the combustion speed of the entire furnace will decrease. In the waste incineration facility 100, such fluctuations in the combustion speed occur constantly. In contrast, the combustion of pulverized coal, oil, or natural gas burns up instantly when supplied to the furnace, so if the supply flow rate is constant, the combustion speed will also be constant.

[0030] Fluctuations in the combustion rate q cause fluctuations in the measured value y of the waste incineration facility 100. The fluctuations in both are approximated by a linear equation, as shown in equation (2). y = c1 × q (2) In the following, the measurement value y is specifically described as being the steam flow rate, the combustion chamber temperature, and the oxygen concentration of the exhaust gas. These are just examples, and the measurement value y may be the two-pass temperature of the boiler, the NOx concentration of the exhaust gas, the CO concentration of the exhaust gas, the primary combustion air flow rate, the secondary combustion air flow rate, etc. c1 in equation (2) is a coefficient vector with 3 rows and 1 column. c1 represents the fluctuation of the measurement value y, that is, the steam flow rate, the combustion chamber temperature, and the oxygen concentration of the exhaust gas, when the combustion speed increases. If the amount of combustion increases, the steam flow rate increases, the combustion chamber temperature increases, and the oxygen concentration of the exhaust gas decreases. c1 is a coefficient vector that quantifies the increase or decrease.

[0031] Equation (2) gives the fluctuation of the measurement value y from the fluctuation of the combustion speed q, but as it is, it is not possible to back-calculate the combustion speed q. Below, we will explain a method for estimating the combustion speed from the fluctuation of the measurement value y. First, we create a measurement value vector y with measurement values ​​such as steam flow rate, combustion chamber temperature, and oxygen concentration of exhaust gas as column elements, and find the variance-covariance matrix Q0 using equation (3). Var(y) represents the variance-covariance matrix of vector y. Q0 = Var(y) (3) Next, the variance-covariance matrix Q0 is subjected to singular value decomposition to obtain the singular vector u i (i=1, 2, 3) and singular value σ 2 i (i=1,2,3). Here, the singular values ​​are sorted in order of magnitude according to the convention of singular value decomposition. That is, σ 2 1 is the largest singular value, σ 2 3 is the smallest singular value. The symbol T on the right represents the transpose of a matrix or vector.

[0032]

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[0033] Next, assuming that there is an unknown disturbance ρ, the fluctuation of the measurement value y is expressed as a singular vector u and the unknown disturbance ρ, as in equation (5) below. The unknown disturbance ρ contains the fluctuation q of the combustion speed in equation (2) as a component, but its actual state is not yet known. The relationship between the two is explained below. The value of u is determined by performing singular value decomposition on the variance-covariance matrix Q0 of the measurement value vector y. Assuming that the measurement value vector y fluctuates due to the unknown disturbance ρ, the measurement value vector y is expressed as a linear combination of ρ, as in equation (5). The elements of ρ are represented as ρi (i = 1, 2, 3).

[0034]

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[0035] Due to the symmetry of the variance-covariance matrix Q0, the singular vector u has the property of equation (6).

[0036]

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[0037] Therefore, from equations (5) and (6), the value of ρ is explicitly determined as in equation (5A).

[0038]

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[0039] The variance-covariance matrix of ρ is given by equation (7).

[0040]

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[0041] The variance of the first component of the unknown disturbance, ρ1, is the maximum singular value σ1, as shown in equation (7). 2 Therefore, the fluctuation of the measurement value vector y is mainly caused by ρ1. Because, due to the nature of singular values, Var(y1)+Var(y2)+Var(y3)=σ1 2+σ2 2 +σ3 2 (8) holds, and in particular, σ1 2 >>σ2 2 +σ3 2 If so, it can be approximated as in the following equation (8A).

[0042]

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[0043] Equation (8A) indicates that the fluctuations in the measurement value vector y are governed by ρ1. On the other hand, since it is known that the fluctuations in the measurement values ​​of the waste incineration facility 100 are due to fluctuations in the combustion speed, it is reasonable to use ρ1 as an estimate of the combustion rate q. By extracting the part related to the calculation of ρ1 from equation (5A), equation (9) is obtained as an estimate of the combustion rate fluctuations. According to equation (9), the estimated value of the combustion rate q can be calculated quickly with a small amount of calculation based on the measurement value y.

[0044]

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[0045] As described above, the combustion rate q may be estimated using the boiler two-pass temperature, the CO concentration in the exhaust gas, the NOx concentration in the exhaust gas, the primary combustion air flow rate, the secondary combustion air flow rate, etc. instead of or in addition to the combustion chamber temperature, the oxygen concentration in the exhaust gas, and the steam flow rate.

[0046] The above-mentioned method for estimating the burning speed q is merely an example, and is not intended to be limiting. For example, an estimation model for estimating the burning speed q may be created using a technique such as a neural network or deep learning.

[0047] The control unit 23 controls the operation of the waste incineration facility 100. For example, while monitoring the steam flow rate measured by the steam flow rate sensor 11, the control unit 23 calculates the amount of waste to be supplied to the combustion chamber 6 and the amount of combustion air to be supplied to the combustion chamber 6, and adjusts these to control the combustion of the waste. Specifically, the control unit 23 supplies a desired amount of combustion air to the combustion chamber 6 by controlling the rotation speed of the blower 4 and the opening degree of the valves 8A to 8E and the valve 14A, and supplies a desired amount of waste to the combustion chamber 6 by controlling the pusher 10. For example, the control unit 23 calculates the amount of waste to be supplied based on the deviation between the measured value and the set value of the steam flow rate, and calculates the amount of combustion air to be supplied based on the set value of the steam flow rate. In addition to this, in the present disclosure, the control unit 23 calculates the amount of waste to be supplied and the amount of combustion air to be supplied by taking into account the real-time combustion rate q estimated by the combustion rate estimation unit 22 (first to sixth embodiments).

[0048] The storage unit 24 stores the information acquired by the data acquisition unit 21 and information necessary for control, such as the steam flow rate set value SV.

[0049] First Embodiment The control of the waste incineration plant 100 of the first embodiment will be described with reference to FIG. (composition) FIG. 2 is a diagram illustrating an example of a functional configuration of a main part of the control device according to the first embodiment. 2 shows the configuration of the main components of the control device 20, the combustion rate estimation unit 22 and the control unit 23. The combustion rate estimation unit 22 estimates the combustion rate q by the above-mentioned procedure. The control unit 23 includes a coefficient calculation table 231 and a PI controller 232. The memory unit 24 stores a set value SV of the steam flow rate. The waste incineration plant 100 is operated so that the steam flow rate measured by the steam flow sensor 11 becomes the set value SV.

[0050] The control unit 23 changes the strength of the dust supply control in accordance with the combustion speed q. For example, if a PI controller is used to adjust the amount of dust supply, the value of the proportional gain is changed in accordance with the combustion speed q. As shown in the coefficient calculation table 231 of FIG. 2, the gain variation coefficient β is set in advance as a function of the combustion speed q. The control unit 23 refers to the coefficient calculation table 231 based on the combustion speed q, and obtains the coefficient β corresponding to the combustion speed q. The PI controller 232 receives, for example, a set value (target value) SV of the steam flow rate (t / h) and a measured value PV by the steam flow rate sensor 11, and performs a PI calculation (proportional integral calculation) of the deviation to obtain the amount of dust supply (m 3 / h) is output as MV. In this case, the proportional gain K P is changed by multiplying it by a gain variation coefficient β.

[0051]

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[0052] As for how to change it, when the combustion rate q is small, i.e., when it is difficult to burn (above (b)), there is no need to add any more garbage since there is unburned garbage remaining in the furnace. Therefore, the proportional gain, which increases the garbage supply amount in proportion to the steam flow rate deviation, is set to, for example, half the normal value. When changing the proportional gain of the PI controller 232 during operation, the controller is generally implemented with a speed-type algorithm. In addition to the proportional gain, the PI controller 232 also changes the integral time constant T I is also a tuning constant. The integral time constant T I Similarly to the proportional gain, the proportional gain may be changed according to the combustion speed q. The control unit 23 controls the extrusion amount of the pusher 10 based on the MV output by the PI controller 232.

[0053] (operation) Next, the flow of processing (dust supply amount control) according to the first embodiment will be described with reference to FIG. FIG. 3 is a diagram illustrating an example of the operation of the control device according to the first embodiment. The data acquisition unit 21, the combustion rate estimation unit 22, and the control unit 23 execute the following processes at predetermined time intervals.

[0054] The data acquisition unit 21 acquires the steam flow rate PV measured by the steam flow rate sensor 11, the O2 concentration measured by the oxygen concentration sensor 15, the temperature of the combustion chamber 6 measured by the temperature sensor 16, the temperature of the boiler 2 path measured by the temperature sensor 17A, the CO concentration of the exhaust gas measured by the CO concentration sensor 17B, the NOx concentration of the exhaust gas measured by the NOx concentration sensor 17C, the primary combustion air flow rate measured by the flow rate sensor 17D, and the secondary combustion air flow rate measured by the flow rate sensor 17E (step S1), and outputs these values ​​to the combustion speed estimation unit 22 and the control unit 23.

[0055] The combustion speed estimation unit 22 estimates the combustion speed q according to equation (9) using preferably a plurality of (or one) measured values ​​y among the steam flow rate PV, oxygen concentration, combustion chamber temperature, temperature of the second boiler path, the CO concentration sensor, the NOx concentration, the primary combustion air flow rate, and the secondary combustion air flow rate (step S2). The combustion speed estimation unit 22 outputs the combustion speed q to the control unit 23.

[0056] Next, the control unit 23 calculates the coefficient β based on the combustion rate q and the coefficient calculation table 231. Next, the control unit 23 reads out the steam flow rate set value SV stored in the memory unit 24, and calculates the garbage supply amount MV based on the calculated coefficient β, the steam flow rate set value SV, the steam flow rate PV acquired by the data acquisition unit 21, and equation (10) (step S3). The control unit 23 controls the movement amount (extrusion amount) of the pusher 10 so that the garbage supply amount MV can be supplied into the furnace.

[0057] According to this embodiment, the waste combustion speed of the entire furnace is estimated based on the measured values ​​of sensors already installed in the waste incineration facility 100, such as the steam flow rate, the combustion chamber temperature, and the oxygen concentration of the exhaust gas, and the set value (gain) of the PI controller 232 that feeds back the deviation between the set value of the steam flow rate and the measured value to the waste supply is changed. This makes it possible to equalize the steam flow rate to the turbine, increase and stabilize the amount of power generation. Furthermore, stabilizing the combustion in the combustion chamber 6 makes it possible to suppress emissions of NOx, CO, etc.

[0058] In addition, according to this embodiment, (E1) the waste combustion rate q is estimated based on the measured values ​​of sensors (sensors reflecting fluctuations in the combustion rate) already installed in the waste incineration facility 100, such as the steam flow rate, the temperature of the combustion chamber, and the oxygen concentration of the exhaust gas, so that it is not necessary to add a new sensor. (E2) By using the combustion rate independent of the waste supply rate as an index, rather than focusing on a specific factor such as the moisture content of the waste as a cause of fluctuations in the heat value, the effect is not limited to the specific factor of interest, and even if the combustion state fluctuates due to various factors, the fluctuation can be detected and linked to control (the effect is not limited). (E3) If the heat value relative to the waste supply rate is used as the control index, an error occurs in the estimation of the heat value due to the time difference between when the waste is supplied and when it is burned, but in this disclosure, the combustion rate is used as the index instead of the heat value. While the heat value is the heat value per unit mass of the waste supplied, the combustion rate represents the heat generated by the entire furnace and is not dependent on the mass of the waste in the furnace. This prevents errors from occurring as occurs when the heat value is used as the control index. The following effects can be obtained.

[0059] Second Embodiment The control of the waste incineration plant 100 according to the second embodiment will be described with reference to Figs. (composition) FIG. 4 is a diagram illustrating an example of a functional configuration of a main part of a control device according to the second embodiment. 4 shows the configuration of the main components of the control device 20, namely, the combustion rate estimation unit 22 and the control unit 23A. The combustion rate estimation unit 22 estimates the combustion rate q by the above-mentioned procedure. The control unit 23A includes a primary combustion air valve adjustment amount calculation table 233 and an adder 234. The memory unit 24 records the set value SV of the steam flow rate and the reference openings of the valves 8A-8E and the valve 14A relative to the set value SV.

[0060] The second embodiment is mainly effective when the combustion in the furnace is excessively vigorous, that is, when the combustion rate q is high. Combustion air is supplied to the waste incineration facility 100 by the blower 4. A part of the air passes through the wind boxes 5A-5E as primary combustion air, and flows into the combustion chamber 6 after penetrating the garbage layer piled up on the grate 3 from bottom to top. When the primary combustion air penetrates the garbage layer, a part of the primary combustion air is used for combustion inside the garbage layer, and the combustible pyrolysis gas generated in the garbage layer by the heat generated by the primary combustion air is carried to the combustion chamber 6 along with the primary combustion air and burns in the combustion chamber 6. In this way, the garbage layer functions as a generator of pyrolysis gas by supplying the primary combustion air. Therefore, if the primary combustion air is restricted, the generation of pyrolysis gas is reduced, and the combustion rate in the furnace can be reduced. Adjusting the heat generation in the furnace by adjusting the primary combustion air is particularly effective when the combustion rate q is high. In such a situation, there is a sufficient amount of garbage in the furnace, and even if the supply of garbage is completely stopped, there may be cases where excessive combustion occurs. In such a case, the combustion of the waste inside the furnace must be restricted. To achieve this, restricting the primary combustion air is effective. Conversely, when combustion inside the furnace is insufficient, i.e., when the combustion rate q is low, it is effective to increase the primary combustion air to increase the generation of pyrolysis gas. As a result, the supply of pyrolysis gas to the combustion chamber 6 increases, and the combustion rate q increases. In this way, the control according to the second embodiment acts to suppress fluctuations in the combustion rate q.

[0061] The opening degree of the primary combustion air valve is determined as a reference value according to the set value SV of the steam flow rate. In the adjustment amount calculation table 233 of the primary combustion air valve, as shown in FIG. 4, the relationship between the combustion speed q and the correction amount Δγ1 for the reference value of the opening degree of the primary combustion air valve based on the set value SV is determined. The control unit 23 calculates the adjustment amount Δγ1 of the valve opening degree of the primary combustion air based on the combustion speed q and the adjustment amount calculation table 233. The value of the adjustment amount Δγ1 is set to be large when the value of the combustion speed q is small, and to be large when the value of q is small. The control unit 23 adjusts the opening degree of the primary combustion air valve by adding the adjustment amount Δγ1 to the reference value of the opening degree of the primary combustion air valve using the adder 244. The control unit 23 controls the valves 8A to 8E based on the adjusted opening degree of the primary combustion air valve.

[0062] (operation) Next, with reference to FIG. 5, a flow of a process (control of the flow rate of primary combustion air) according to the second embodiment will be described. FIG. 5 is a diagram illustrating an example of the operation of the control device according to the second embodiment. The data acquisition unit 21, the combustion rate estimation unit 22, and the control unit 23A execute the following processes at predetermined time intervals.

[0063] The data acquisition unit 21 acquires the steam flow rate PV, O2 concentration, combustion chamber temperature, temperature of the boiler 2 passes, CO concentration, NOx concentration, primary combustion air flow rate, and secondary combustion air flow rate (step S1), and outputs these measurement values ​​to the combustion speed estimation unit 22 and the control unit 23A.

[0064] The combustion speed estimation unit 22 estimates the combustion speed q by using a plurality of measured values ​​y from among the steam flow rate PV, O2 concentration, combustion chamber temperature, temperature of the second boiler path, the CO concentration sensor, the NOx concentration, the primary combustion air flow rate, and the secondary combustion air flow rate (step S2) according to equation (9). The combustion speed estimation unit 22 outputs the estimated combustion speed q to the control unit 23A.

[0065] Next, the control unit 23A calculates an adjustment amount Δγ1 of the valve aperture of the primary combustion air based on the combustion speed q and the adjustment amount calculation table 233. Next, the control unit 23A calculates the valve aperture of the primary combustion air by adding the reference value of the valve aperture of the primary combustion air corresponding to the set value SV of the steam flow rate stored in the memory unit 24 and the adjustment amount Δγ1 using the adder 234 (step S4). The control unit 23A controls the apertures of the valves 8A-8E to the valve apertures of the primary combustion air after adjustment.

[0066] According to this embodiment, the combustion rate q of the waste is estimated based on the measured values, such as the steam flow rate, the combustion chamber temperature, and the oxygen concentration of the exhaust gas, measured by sensors already installed in the waste incineration facility 100, and the primary combustion air flow rate is adjusted based on the combustion rate q. This makes it possible to suppress the fluctuation of the combustion rate q. Also, in the same manner as in the first embodiment, it is possible to obtain the effects (E1) to (E3). The second embodiment can be combined with the first embodiment.

[0067] In addition, in Fig. 4, as an example, the primary combustion air is adjusted by adjusting the valve opening of the primary combustion air, but as another method, if the primary combustion air flow rate is controlled by a command value, the command value of the primary combustion air flow rate may be adjusted. Alternatively, the source pressure (upstream pressure) of the primary combustion air may be adjusted.

[0068] <Third embodiment> The control of the waste incineration plant 100 according to the third embodiment will be described with reference to Figs. (composition) FIG. 6 is a diagram illustrating an example of a functional configuration of a main part of a control device according to the third embodiment. 6 shows the configuration of the main components of the control device 20, namely, the combustion rate estimation unit 22 and the control unit 23B. The combustion rate estimation unit 22 estimates the combustion rate q by the above-mentioned procedure. The control unit 23B includes a primary combustion air valve adjustment amount calculation table 233, an adder 234, a secondary combustion air valve adjustment amount calculation table 235, and an adder 236. The memory unit 24 stores the set value SV of the steam flow rate and the reference openings of the valves 8A-8E and the valve 14A relative to the set value SV.

[0069] In the third embodiment, in addition to the opening control of the primary combustion air valve described in the second embodiment, the opening control of the secondary combustion air valve is also performed. Suppose that the combustion rate q of the garbage is temporarily excessive. At this time, the generation of pyrolysis gas in the furnace is temporarily excessive, and as a result, the O2 concentration of the exhaust gas from the garbage incineration facility 100 is temporarily insufficient. If the O2 concentration of the exhaust gas is insufficient, the risk of emitting harmful substances such as CO increases. Therefore, in the third embodiment, the primary combustion air is adjusted based on the combustion rate q, and at the same time, the secondary combustion air is also adjusted to compensate for the insufficiency of the O2 concentration. For example, when the combustion rate q is excessive, the primary combustion air is reduced to suppress the generation of pyrolysis gas, and the secondary combustion air is increased to burn the excess pyrolysis gas. Conversely, when the combustion rate q is too low, the primary combustion air is increased to promote the generation of pyrolysis gas. The secondary combustion air is reduced because it is excessive compared to the amount of pyrolysis gas generated. This also helps to avoid the generation of NOx.

[0070] As shown in FIG. 6, the secondary combustion air valve adjustment amount calculation table 235 defines the relationship between the combustion speed q and the correction amount Δγ2 for the reference value of the secondary combustion air valve opening. The control unit 23B calculates the adjustment amount Δγ2 of the secondary combustion air valve opening based on the combustion speed q and the adjustment amount calculation table 235. The value of the adjustment amount Δγ2 is set to be small when the value of the combustion speed q is small and to be large when the value of the combustion speed q is large. The control unit 23B adjusts the secondary combustion air valve opening by adding the adjustment amount Δγ2 to the reference value of the secondary combustion air valve opening using the adder 245. The control unit 23B controls the valve 14A based on the adjusted secondary combustion air valve opening.

[0071] (operation) Next, with reference to FIG. 7, a flow of a process (control of the flow rates of primary combustion air and secondary combustion air) according to the third embodiment will be described. FIG. 7 is a diagram illustrating an example of the operation of the control device according to the third embodiment. The data acquisition unit 21, the combustion rate estimation unit 22, and the control unit 23B execute the following processes at predetermined time intervals.

[0072] Data acquisition unit 21 acquires measured values ​​such as steam flow rate PV (step S1) and outputs them to combustion rate estimation unit 22 and control unit 23B. Next, combustion rate estimation unit 22 estimates combustion rate q (step S2). Burning rate estimation unit 22 outputs combustion rate q to control unit 23B.

[0073] Next, the control unit 23B calculates the adjustment amount Δγ1 of the primary combustion air valve aperture based on the combustion speed q and the adjustment amount calculation table 233. Next, the control unit 23 uses the adder 234 to add the adjustment amount Δγ1 to the reference value of the primary combustion air valve aperture corresponding to the set value SV of the steam flow rate stored in the memory unit 24, to calculate the primary combustion air valve aperture (step S4). The control unit 23 controls the apertures of the valves 8A to 8E to the adjusted valve apertures of the primary combustion air.

[0074] Furthermore, the control unit 23B calculates an adjustment amount Δγ2 of the secondary combustion air valve aperture based on the combustion speed q and the adjustment amount calculation table 235. Next, the control unit 23 uses the adder 236 to add the adjustment amount Δγ2 to a reference value of the secondary combustion air valve aperture corresponding to the set value SV of the steam flow rate stored in the memory unit 24 to calculate the valve aperture of the secondary combustion air (step S5). The control unit 23 controls the aperture of the valve 14A to become the valve aperture of the secondary combustion air after the adjustment. The processing order of steps S4 to S5 may be arbitrary, and for example, the control unit 23B may simultaneously perform the processing of steps S4 to S5 in parallel.

[0075] According to this embodiment, the combustion speed q of the waste is estimated based on the measured values ​​of sensors already installed in the waste incineration facility 100, such as the steam flow rate, the combustion chamber temperature, and the oxygen concentration of the exhaust gas, and the primary combustion air flow rate and the secondary combustion air flow rate are adjusted based on the combustion speed q of the waste. This allows the secondary combustion air to be adjusted according to the amount of pyrolysis gas generated, helping to completely combust the pyrolysis gas, and suppressing the emission of harmful substances such as CO and NOx. Also, in the same manner as the first embodiment, the effects (E1) to (E3) can be obtained. The third embodiment can be combined with the first embodiment.

[0076] <Fourth embodiment> The control of the waste incineration power generation plant 100 according to the fourth embodiment will be described with reference to FIG. (composition) FIG. 8 is a diagram illustrating an example of a functional configuration of a main part of a control device according to the fourth embodiment. 8 shows the configuration of the main parts of the control device 20, namely, the combustion rate estimation unit 22 and the control unit 23C. The combustion rate estimation unit 22 estimates the combustion rate q by the above-mentioned procedure. The control unit 23C includes a wind box allocation adjustment opening calculation table 237, an adder 238, and a subtractor 239. The memory unit 24 records the reference openings of the valves 8A to 8E with respect to the set value SV of the steam flow rate.

[0077] In the fourth embodiment, in order to suppress the fluctuation of the combustion speed q, the amount of combustion air supplied to the wind boxes 5A to 5E is made different in the opening control of the primary combustion air valve, taking into consideration the tendency of the garbage to burn in the combustion chamber 6. The garbage layer has an aspect of being a generator of pyrolysis gas. The magnitude of the pyrolysis gas generation capacity depends on the position of the wind boxes 5A to 5E. The wind boxes 5A and 5B close to the pusher 10 have a thick garbage layer before pyrolysis, so they have a high pyrolysis gas generation capacity. On the other hand, as the garbage advances through the wind boxes 5C, 5D, and 5E and the grate 3, the ratio of garbage and coals after pyrolysis increases, and the pyrolysis gas generation capacity decreases. Therefore, when the estimated combustion speed q is small, that is, when the garbage is difficult to burn, more primary combustion air is distributed to the wind boxes 5A and the like close to the pusher 10, which have a high pyrolysis gas generation capacity, and conversely, when the estimated value q of the combustion speed is large, that is, when the garbage is easy to burn, the distribution of primary combustion air to the wind boxes 5A and the like, which have a high pyrolysis gas generation capacity, is reduced to suppress combustion.

[0078] 8 shows a configuration in which wind boxes A and B are classified as a group with a high pyrolysis gas generation capacity, and wind boxes C, D, and E are classified as a group with a low pyrolysis gas generation capacity. As shown in FIG. 8, the wind box distribution adjustment opening calculation table 237 includes a correction amount Δγ for the reference value of the valve opening of the wind boxes 5A to 5B and the wind boxes 5C to 5E, and a correction amount Δγ for the reference value of the valve opening of the wind boxes 5A to 5B and the wind boxes 5C to 5E. ABCDE The control unit 23C calculates the adjustment amount Δγ of the opening of the valves 8A to 8E based on the combustion speed q and the wind box allocation adjustment opening calculation table 237. ABCDE Calculate the adjustment amount Δγ ABCDE The value of is set to be large when the combustion speed q is low and to be small when the combustion speed q is high. The control unit 23C uses the adder 238 to calculate the adjustment amount Δγ ABCDE The control unit 23C uses a subtractor 239 to add the adjustment amount Δγ ABCDE is subtracted from the reference values ​​of the openings of the valves 8C to 8E. The control unit 23B controls the valves 8A to 8E based on the adjusted valve openings.

[0079] In Fig. 8, the wind boxes 5A-5B are set as one group, and the wind boxes 5C-5E are set as one group, but this is merely an example. Instead of grouping the wind boxes 5A-5E, a wind box distribution adjustment opening calculation table 237 may be provided for each wind box to adjust the opening of the valves 8A-8E, or the grouping may be changed to, for example, wind boxes 5A-5C and wind boxes 5D-5E. Also, the number of groups to be classified may be set to three, and the classification of each group may be set as wind boxes 5A-5B, wind boxes 5C-5D, and wind box 5E.

[0080] (operation) The flow of processing according to the fourth embodiment will be described with reference to FIG. 5 of the second embodiment. The data acquisition unit 21, the combustion rate estimation unit 22, and the control unit 23C execute the following processes at predetermined time intervals.

[0081] Data acquisition unit 21 acquires measured values ​​such as steam flow rate PV (step S1) and outputs them to combustion rate estimation unit 22 and control unit 23C. Next, combustion rate estimation unit 22 estimates combustion rate q (step S2). Burning rate estimation unit 22 outputs combustion rate q to control unit 23C.

[0082] Next, the control unit 23C calculates the adjustment amount Δγ based on the combustion speed q and the wind box allocation adjustment opening calculation table 237. ABCDE Next, the control unit 23 calculates the reference value and adjustment amount Δγ of the valve opening of the valves 8A to 8E corresponding to the set value SV of the steam flow rate stored in the memory unit 24. ABCDE In the case of the configuration example of FIG. 8, the control unit 23 calculates the valve opening degree of the primary combustion air by adding or subtracting the adjustment amount Δγ ABCDE The control unit 23 adds an adjustment amount Δγ ABCDE The control unit 23 controls the opening degrees of the valves 8A to 8E so that they become equal to the adjusted valve opening degrees.

[0083] According to the fourth embodiment, the combustion rate q of the waste is estimated based on the measured values ​​of sensors already installed in the waste incineration facility 100, such as the steam flow rate, the combustion chamber temperature, and the oxygen concentration of the exhaust gas, and the ratio of the flow rate of the primary combustion air distributed to the wind box is adjusted based on the estimated combustion rate q of the waste. This makes it possible to accurately suppress the fluctuation of the combustion rate q. Also, in the same way as the first embodiment, it is possible to obtain the effects (E1) to (E3). The fourth embodiment can be combined with the first and third embodiments.

[0084] <Fifth embodiment> The control of the waste incineration power generation plant 100 according to the fifth embodiment will be described with reference to Figs. (composition) FIG. 9 is a diagram illustrating an example of a functional configuration of a main part of a control device according to the fifth embodiment. 9 shows the configuration of the main parts of the control device 20, namely, the combustion speed estimation unit 22 and the control unit 23D. The combustion speed estimation unit 22 estimates the combustion speed q by the above-mentioned procedure. The control unit 23D includes a variance calculator 240, an oxygen concentration adjustment amount calculation table 241, an oxygen concentration controller 242, adders 243-245, and a subtractor 246. The memory unit 24 records the reference openings of the valves 8A-8E and the valve 14A relative to the steam flow rate set value SV, and the O2 concentration set value SV_O2.

[0085] In the third embodiment described above, the secondary combustion air flow rate is adjusted simultaneously with the primary combustion air flow rate based on the combustion rate q of the waste. One of the reasons for adjusting the secondary combustion air is to reduce the CO concentration in the combustion chamber 6. For example, if the primary combustion air is adjusted to be reduced, there will be a shortage of combustion air in the waste layer, and the CO concentration in the pyrolysis gas will increase. Therefore, the secondary combustion air is increased and the CO concentration is reduced by completely burning the CO in the combustion chamber 6. However, if the combustion rate of the waste increases rapidly over time, there is a risk that the adjustment of the primary combustion air and the secondary combustion air will not be in time and CO will be temporarily emitted. It is believed that such a sudden increase in the combustion rate depends on the nature of the waste supplied. It is known from experience that once a sudden increase in the combustion rate occurs, it will occur intensively in a short period of time. Therefore, in the fifth embodiment, when a fluctuation in the combustion rate q occurs, the flow rate of the secondary combustion air or the primary combustion air is increased in advance, the O2 concentration of the exhaust gas is maintained high, and even if the combustion rate q increases, a shortage of combustion air is avoided and CO emission is prevented.

[0086] The variance calculator 240 calculates the variance σ of the burning speed q estimated by the burning speed estimation unit 22 at a predetermined time immediately before the q 2 In the oxygen concentration adjustment amount calculation table 241, as shown in FIG. q 2 and the oxygen concentration adjustment amount Δγ SVO2 The relationship between the adjustment amount Δγ SVO2 The value of variance σ q 2 If the value is less than the threshold, it is 0. If it is more than the threshold, the variance σ q 2 The oxygen concentration controller 242 calculates the primary combustion air valve adjustment opening and the secondary combustion air valve adjustment opening based on the deviation between the adjusted O2 concentration set value SV_O2 and the measured O2 concentration value PV_O2 concentration. For example, the oxygen concentration controller 242 calculates adjustment openings that request an increase in the opening of each of the primary combustion air valve adjustment opening and the secondary combustion air valve adjustment opening as the deviation increases.

[0087] (operation) The flow of processing according to the fifth embodiment will be described with reference to FIG. The data acquisition unit 21, the combustion rate estimation unit 22, and the control unit 23D execute the following processes at predetermined time intervals.

[0088] Data acquisition unit 21 acquires measured values ​​such as steam flow rate PV (step S1) and outputs them to combustion rate estimation unit 22 and control unit 23D. Next, combustion rate estimation unit 22 estimates combustion rate q (step S2). Burning rate estimation unit 22 outputs combustion rate q to control unit 23D.

[0089] Next, the control unit 23D calculates the variance σ of the burning rate q using the variance calculator 240. q 2 (Step S6). The control unit 23D calculates the variance σ q 2 According to the magnitude of the variance σ, the control unit 23D calculates the primary combustion air valve opening degree and the secondary combustion air valve opening degree that compensate for the O2 concentration (step S7). q 2 Based on the oxygen concentration adjustment amount calculation table 241, the adjustment amount Δγ of the O2 concentration is calculated. SVO2 Next, the adder 243 calculates the adjustment amount Δγ of the O2 concentration to the set value SV_O2 of the O2 concentration. SVO2Next, the subtractor 246 subtracts the measured value PV_O2 measured by the oxygen concentration sensor 15 from the adjusted SV_O2. Next, the oxygen concentration controller 242 calculates the primary combustion air valve adjustment opening and the secondary combustion air valve adjustment opening based on the deviation between the adjusted O2 concentration set value SV_O2 and the measured O2 concentration value PV_O2 concentration. Next, the control unit 23D uses the adder 244 to add the reference value of the valve opening of the primary combustion air corresponding to the set value SV of the steam flow rate and the primary combustion air valve adjustment opening to calculate the valve opening of the primary combustion air. In addition, the control unit 23D controls the opening of the valves 8A to 8E to be the calculated opening. Next, the control unit 23D uses the adder 245 to add the reference value of the valve opening of the secondary combustion air corresponding to the set value SV of the steam flow rate and the secondary combustion air valve adjustment opening to calculate the valve opening of the secondary combustion air. The control unit 23D controls the opening degree of the valve 14A to the calculated opening degree.

[0090] According to this embodiment, the combustion speed q of the waste is estimated based on the measured values ​​of sensors already installed in the waste incineration facility 100, such as the steam flow rate, the combustion chamber temperature, and the oxygen concentration of the exhaust gas, and the set value of the O2 concentration in the exhaust gas is corrected based on the variance of the combustion speed q, and the primary combustion air flow rate and the secondary combustion air flow rate are adjusted according to the set value. This makes it possible to suppress the emission of CO gas. Also, in the same way as in the first embodiment, the effects (E1) to (E3) can be obtained. The fifth embodiment can be combined with the first to fourth embodiments.

[0091] Sixth Embodiment Next, control of the waste incineration power generation plant 100 according to the sixth embodiment will be described with reference to FIG. FIG. 11 is a diagram illustrating an example of a functional configuration of a main part of a control device according to the sixth embodiment. 11 shows the configuration of the main parts of the combustion speed estimation unit 22 and the control unit 23E of the control device 20. The combustion speed estimation unit 22 estimates the combustion speed q by the above-mentioned procedure. The control unit 23E includes a combustion speed commander 247, a combustion speed controller 248, a subtractor 249, a primary combustion air valve adjustment amount calculation table 233, an adder 234, a secondary combustion air valve adjustment amount calculation table 235, and an adder 236. The configuration shown in FIG. 11 is a configuration when combined with the control unit 23B of the third embodiment (primary combustion air valve adjustment amount calculation table 233, adder 234, secondary combustion air valve adjustment amount calculation table 235, and adder 236).

[0092] The burning speed commander 247 calculates a command value qsv for adjusting the burning speed q estimated by the burning speed estimator 22 based on the deviation (SV-PV) between the set value SV of the steam flow rate and the measured value PV of the steam flow rate. The command value qsv commands the burning speed of the waste so that the measured value PV of the steam flow rate coincides with the set value SV, which is the target value of the steam flow rate. By setting the burning speed according to this command value qsv, the steam flow rate PV can be controlled to the target value SV with high accuracy. For example, the burning speed commander 247 has a correspondence table between the deviation (SV-PV) of the steam flow rate and the adjustment amount of the burning speed q, and calculates a burning speed command value qsv for adjusting the burning speed q based on this correspondence table. The burning speed controller 248 acquires the burning speed command value qsv and the burning speed q estimated by the burning speed estimator 22, corrects the burning speed q, for example, according to the following formula (11), and outputs the corrected burning speed q~. q~=q+Kq(qsv-q) (11) Here, Kq is a coefficient of an arbitrary value. The corrected combustion speed q~ is used to adjust the primary combustion air and the secondary combustion air, for example, in the same manner as in the third embodiment. For example, the control unit 23E calculates an adjustment amount Δγ1 based on the corrected combustion speed q~ and a primary combustion air valve adjustment amount calculation table 233, and calculates an adjustment amount Δγ2 based on the corrected combustion speed q~ and a secondary combustion air valve adjustment amount calculation table 235.

[0093] (operation) The flow of processing according to the sixth embodiment will be described with reference to FIG. The data acquisition unit 21, the combustion rate estimation unit 22, and the control unit 23D execute the following processes at predetermined time intervals.

[0094] Data acquisition unit 21 acquires measured values ​​such as steam flow rate PV (step S1) and outputs them to combustion rate estimation unit 22 and control unit 23E. Next, combustion rate estimation unit 22 estimates combustion rate q (step S2). Combustion rate estimation unit 22 outputs combustion rate q to control unit 23E.

[0095] Next, the control unit 23E corrects the combustion speed q (step S8). Specifically, the control unit 23E uses the subtractor 249 to subtract the measured value PV from the set value SV of the steam flow rate. The control unit 23E inputs the deviation (SV-PV) between the set value SV and the measured value PV to the combustion speed command unit 247. The combustion speed command unit 247 calculates the combustion speed command value qsv. The control unit 23E inputs the combustion speed command value qsv and the combustion speed q to the combustion speed controller 248. The combustion speed controller 248 calculates the corrected combustion speed q~ by equation (11). The control unit 23E uses the corrected combustion speed q~ to perform combustion control of the waste incineration power generation facility 100 by calculating the garbage supply amount (first embodiment), the primary combustion air valve opening degree and the secondary combustion air valve opening degree (second to fifth embodiments), and the like.

[0096] According to this embodiment, the waste combustion rate q is estimated based on the measured values ​​of sensors already installed in the waste incineration facility 100, such as the steam flow rate, the combustion chamber temperature, and the oxygen concentration of the exhaust gas, and a command value for the waste combustion rate q is calculated, and the waste combustion rate q is made to match the command value. This makes it possible to accurately control the steam flow rate PV to the set value SV while suppressing fluctuations in the combustion rate q. The sixth embodiment can be combined with the first to fifth embodiments.

[0097] FIG. 13 is a diagram illustrating an example of a hardware configuration of the control device according to each embodiment. The computer 900 includes a CPU 901 , a main memory device 902 , an auxiliary memory device 903 , an input / output interface 904 , and a communication interface 905 . The above-mentioned control device 20 is implemented in a computer 900. The above-mentioned functions are stored in the auxiliary storage device 903 in the form of a program. The CPU 901 reads the program from the auxiliary storage device 903, loads it in the main storage device 902, and executes the above-mentioned processing in accordance with the program. The CPU 901 also reserves a storage area in the main storage device 902 in accordance with the program. The CPU 901 also reserves a storage area in the auxiliary storage device 903 for storing data being processed in accordance with the program.

[0098] In addition, a program for realizing all or part of the functions of the control device 20 may be recorded in a computer-readable recording medium, and the program recorded in the recording medium may be read into a computer system and executed to perform processing by each functional unit. The term "computer system" as used herein includes hardware such as an OS and peripheral devices. In addition, if a WWW system is used, the term "computer system" also includes a homepage providing environment (or display environment). In addition, the term "computer-readable recording medium" refers to a portable medium such as a CD, DVD, or USB, and a storage device such as a hard disk built into a computer system. In addition, if the program is distributed to the computer 900 through a communication line, the computer 900 that receives the program may expand the program in the main storage device 902 and execute the above processing. In addition, the above program may be for realizing part of the above-mentioned functions, and may further be capable of realizing the above-mentioned functions in combination with a program already recorded in the computer system.

[0099] As described above, several embodiments according to the present disclosure have been described, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as described in the claims, as well as in the scope and gist of the invention.

[0100] <Additional Notes> The control device 20, the waste incineration facility 100, the control method and the program described in each embodiment can be understood, for example, as follows.

[0101] (1) The control device 20 of the first embodiment includes a data acquisition unit 21 that acquires measurement values ​​measured by a sensor equipped in the waste incineration equipment, a combustion rate estimation unit 22 that uses the measurement values ​​to estimate a combustion rate q in the incinerator (combustion chamber 6) of the waste incineration equipment, and a control unit 23 that controls the amount of waste supplied or the flow rate of combustion air supplied to the incinerator based on the combustion rate. This allows the fluctuation of combustion in the entire incinerator to be detected as the combustion speed and control to be performed according to the combustion speed, suppressing the fluctuation of the combustion speed and realizing stable operation. For example, supplying a constant steam flow rate to a power generation turbine can contribute to stabilizing and increasing the amount of power generation. In addition, stabilizing combustion can suppress emissions of NOx, CO, etc.

[0102] (2) A control device 20 according to a second aspect is the control device 20 of (1), wherein the burning rate estimation unit estimates the burning rate by multiplying the measurement value by a maximum singular vector corresponding to a maximum singular value obtained by singular value decomposition of a variance-covariance matrix of the measurement value used to estimate the burning rate (equation (9)). This allows the burning speed q to be calculated with a small computational load, so the current burning speed q can be estimated immediately after obtaining a measurement value.

[0103] (3) A control device 20 according to a third aspect is the control device 20 of (1) to (2), wherein the control unit adjusts the magnitude of the gain of a feedback controller that calculates a garbage supply amount that compensates for the deviation between a target value of the steam flow rate output by the garbage incineration facility and the measured value of the steam flow rate based on the combustion speed. By controlling the amount of garbage fed, it is possible to suppress fluctuations in the combustion rate (first embodiment).

[0104] (4) A control device 20 according to a fourth aspect is the control device 20 of (1) to (3), wherein the control unit multiplies the gain by a value smaller than 1 when the combustion speed is smaller than a predetermined threshold value. When the combustion speed is reduced due to an excessive supply of refuse, the combustion speed can be restored by reducing the supply of refuse (first embodiment).

[0105] (5) A control device 20 according to a fifth aspect is the control device 20 of (1) to (4), wherein the control unit controls the opening of a primary combustion air valve, which controls the flow rate of primary combustion air supplied to a primary combustion chamber, which is a space in the incinerator for incinerating waste, in accordance with the magnitude of the combustion speed, so that when the combustion speed is greater than a predetermined threshold value, the opening of the primary combustion air valve is smaller than a reference value, and when the combustion speed is smaller than a predetermined threshold value, the opening of the primary combustion air valve is larger than the reference value. For example, the combustion of waste in the combustion chamber 6 can be stabilized by reducing the amount of primary combustion air supplied when combustion is vigorous and increasing the amount of primary combustion air supplied when combustion is slowing (second embodiment).

[0106] (6) A control device 20 according to a sixth aspect is the control device 20 of (5), wherein the control unit increases the amount of primary combustion air supplied to a position near the garbage inlet in the primary combustion chamber above a predetermined reference value when the combustion rate is smaller than a predetermined threshold value, and decreases the amount of primary combustion air supplied to a position near the garbage inlet in the primary combustion chamber below a predetermined reference value when the combustion rate is larger than a predetermined threshold value. By adjusting the supply amount of primary combustion air for each wind box according to the generation capacity of pyrolysis gas, it is possible to more effectively stabilize the combustion speed (fourth embodiment).

[0107] (7) A control device 20 according to a seventh aspect is the control device 20 of (1) to (6), wherein the control unit controls the opening degree of a secondary combustion air valve, which controls the flow rate of combustion air supplied to a secondary combustion chamber, which is a space for burning combustion gas generated by the incineration of waste in the incinerator, in accordance with the magnitude of the combustion speed, so that when the combustion speed is greater than a predetermined threshold value, the opening degree of the secondary combustion air valve is greater than a reference value, and when the combustion speed is smaller than the predetermined threshold value, the opening degree of the secondary combustion air valve is less than the reference value. The risk of emitting CO, Nox, etc. can be reduced (third embodiment).

[0108] (8) The control device 20 according to an eighth aspect is the control device 20 of (1) to (7), wherein the control unit increases the flow rate of the combustion air when the variance of the combustion speed is equal to or greater than a predetermined threshold value. The O2 concentration in the exhaust gas is maintained high, and a shortage of combustion air is avoided even if the combustion speed increases, thereby making it possible to suppress CO emissions (fifth embodiment).

[0109] (9) A control device 20 according to a ninth aspect is a control device 20 according to any one of (1) to (8), wherein the control unit calculates a command value for the combustion rate that compensates for the deviation between a target value of the steam flow rate output by the waste incineration facility and the measured value of the steam flow rate, and corrects the combustion rate estimated by the combustion rate estimation unit based on the command value. This makes it possible to more accurately achieve the control objective of controlling the steam flow rate output by the waste incineration facility to a target value while suppressing fluctuations in the combustion speed.

[0110] (10) The waste incineration facility of the tenth aspect includes an incinerator (combustion chamber 6) for incinerating waste, a dust feeder (pusher 10) for supplying waste to the incinerator, a blower 4 for supplying combustion air to the incinerator, combustion air valves (8A-8E, 14E) for controlling the flow rate of combustion air supplied from the blower to the incinerator that incinerates waste, and the control device described in (1)-(9).

[0111] (11) A control method according to an eleventh aspect includes the steps of acquiring measurement values ​​measured by a sensor provided in a waste incineration facility, using the measurement values ​​to estimate a combustion rate in an incinerator of the waste incineration facility, and controlling the amount of waste supplied or the flow rate of combustion air supplied to the incinerator based on the combustion rate.

[0112] (12) A program relating to a twelfth aspect causes a computer to execute the steps of acquiring measurement values ​​measured by a sensor equipped in a waste incineration facility, using the measurement values ​​to estimate a combustion rate in an incinerator of the waste incineration facility, and controlling the amount of waste supplied or the flow rate of combustion air supplied to the incinerator based on the combustion rate. [Explanation of symbols]

[0113] 100: Waste incineration equipment, 1: Hopper, 2: Chute, 3: Fire grate, 3A: Drying area, 3B: Combustion area, 3C: Post-combustion area, 4: Blower, 5A to 5E...wind box, 6...combustion chamber, 6A...primary combustion chamber, 6B...secondary combustion chamber, 7...ash outlet, 8A to 8E, 14A...valve, 9...boiler, 10...pusher, 11...steam flow sensor, 12...flue, 13, 14...pipe, 15...oxygen concentration sensor, 16, 17A...temperature sensor, 17B...CO concentration sensor, 17C...NOx concentration sensor, 17 D···Flow rate sensor, 17E···Flow rate sensor, 20···Control device, 21···Data acquisition unit, 22···Combustion rate estimation unit, 23, 23A, 23B, 23C, 23D, 23E···Control unit, 24···Storage unit, 900···Computer, 901···CPU, 902···Main storage device, 903···Auxiliary storage device, 904···Input / output interface, 905···Communication interface

Claims

1. A data acquisition unit that acquires measurement values ​​measured by sensors provided in the waste incineration facility; A combustion rate estimation unit that estimates a combustion rate in the incinerator of the waste incineration facility using the measured value; A control unit that controls the amount of garbage supplied or the flow rate of combustion air supplied to the incinerator based on the combustion speed; Equipped with the burning speed estimating unit estimates the burning speed by multiplying the measurement value by a maximum singular vector corresponding to a maximum singular value obtained by singular value decomposition of a variance-covariance matrix of the measurement value used for estimating the burning speed; Control device.

2. A data acquisition unit that acquires measurement values ​​measured by sensors provided in the waste incineration facility; A combustion rate estimation unit that estimates a combustion rate in the incinerator of the waste incineration facility using the measured value; A control unit that controls the amount of garbage supplied or the flow rate of combustion air supplied to the incinerator based on the combustion speed; Equipped with The control unit adjusts the magnitude of a gain of a feedback controller that calculates a garbage supply amount that compensates for a deviation between a target value of a steam flow rate output by the garbage incineration facility and the measured value of the steam flow rate, based on the combustion speed. Control device.

3. The control unit multiplies the gain by a value smaller than 1 when the combustion speed is smaller than a predetermined threshold value. The control device according to claim 2.

4. A data acquisition unit that acquires measurement values ​​measured by sensors provided in the waste incineration facility; A combustion rate estimation unit that estimates a combustion rate in the incinerator of the waste incineration facility using the measured value; A control unit that controls the amount of garbage supplied or the flow rate of combustion air supplied to the incinerator based on the combustion speed; Equipped with The control unit controls the opening degree of a primary combustion air valve, which controls the flow rate of primary combustion air supplied to a primary combustion chamber, which is a space in the incinerator for incinerating waste, in accordance with the magnitude of the combustion speed, so that when the combustion speed is greater than a predetermined threshold value, the opening degree of the primary combustion air valve is smaller than a reference value, and when the combustion speed is smaller than the predetermined threshold value, the opening degree of the primary combustion air valve is larger than the reference value. Control device.

5. The control unit increases the amount of primary combustion air supplied to a position near a garbage inlet in the primary combustion chamber to a level higher than a predetermined reference value when the combustion speed is lower than a predetermined threshold value, and decreases the amount of primary combustion air supplied to a position near a garbage inlet in the primary combustion chamber to a level lower than a predetermined reference value when the combustion speed is higher than a predetermined threshold value. The control device according to claim 4.

6. A data acquisition unit that acquires measurement values ​​measured by sensors provided in the waste incineration facility; A combustion rate estimation unit that estimates a combustion rate in the incinerator of the waste incineration facility using the measured value; A control unit that controls the amount of garbage supplied or the flow rate of combustion air supplied to the incinerator based on the combustion speed; Equipped with The control unit controls the opening degree of a secondary combustion air valve, which controls the flow rate of combustion air supplied to a secondary combustion chamber, which is a space for burning combustion gas generated by the incineration of waste in the incinerator, in accordance with the magnitude of the combustion speed, so that the opening degree of the secondary combustion air valve is greater than a reference value when the combustion speed is greater than a predetermined threshold value, and so that the opening degree of the secondary combustion air valve is smaller than the reference value when the combustion speed is less than the predetermined threshold value. Control device.

7. A data acquisition unit that acquires measurement values ​​measured by sensors provided in the waste incineration facility; A combustion rate estimation unit that estimates a combustion rate in the incinerator of the waste incineration facility using the measured value; A control unit that controls the amount of garbage supplied or the flow rate of combustion air supplied to the incinerator based on the combustion speed; Equipped with The control unit increases the flow rate of the combustion air when the variance of the combustion speed is equal to or greater than a predetermined threshold value. Control device.

8. A data acquisition unit that acquires measurement values ​​measured by sensors provided in the waste incineration facility; A combustion rate estimation unit that estimates a combustion rate in the incinerator of the waste incineration facility using the measured value; A control unit that controls the amount of garbage supplied or the flow rate of combustion air supplied to the incinerator based on the combustion speed; Equipped with The control unit calculates a command value for the combustion rate that compensates for a deviation between a target value of the steam flow rate output by the waste incineration facility and the measured value of the steam flow rate, and corrects the combustion rate estimated by the combustion rate estimation unit based on the command value. Control device.

9. An incinerator for burning garbage, A dust feeder for feeding refuse to the incinerator; A blower for supplying combustion air to the incinerator; A combustion air valve for controlling the flow rate of combustion air supplied from the blower to the incinerator; A control device according to any one of claims 1 to 8; A waste incineration facility equipped with:

10. A step of acquiring measured values ​​measured by a sensor provided in the waste incineration facility; A step of estimating a combustion rate in an incinerator of the waste incineration facility using the measured value; A step of controlling the amount of garbage supplied or the flow rate of combustion air supplied to the incinerator based on the combustion speed; having In the step of estimating the burning speed, the burning speed is estimated by multiplying the measured value by a maximum singular vector corresponding to a maximum singular value obtained by singular value decomposition of a variance-covariance matrix of the measured value used for estimating the burning speed. Control methods.

11. On the computer, A step of acquiring measured values ​​measured by a sensor provided in the waste incineration facility; A step of estimating a combustion rate in an incinerator of the waste incineration facility using the measured value; A step of controlling the amount of garbage supplied or the flow rate of combustion air supplied to the incinerator based on the combustion speed; having In the step of estimating the burning velocity, a process of estimating the burning velocity by multiplying the measured value by a maximum singular vector corresponding to a maximum singular value obtained by singular value decomposition of a variance-covariance matrix of the measured value used for estimating the burning velocity; A program that executes the following.

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