Estimation device, coal pulverizing apparatus, plant, estimation method, and program

Abstract

To provide a technique for estimating the moisture content of coal.SOLUTION: The estimation device includes an estimation unit configured to estimate, for a raw coal moisture percentage indicating a moisture percentage of coal supplied to a coal pulverizing apparatus, a raw coal moisture percentage at time t + 1 by adding a value obtained by multiplying a difference between heat input to the coal pulverizing apparatus and heat output from the coal pulverizing apparatus at time t by a gain to an estimated value of the raw coal moisture percentage at time t.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a moisture content estimation device for raw coal or pulverized coal, a coal crushing device, a plant, an estimation method, and a program. [Background technology]

[0002] Patent Document 1 discloses a power generation facility that generates electricity by burning coal pulverized by a coal pulverizer to generate steam, and then using the steam to rotate a turbine. Patent Document 1 also discloses a control method that increases or decreases the amount of coal supplied to the coal pulverizer without delay in order to quickly respond to load fluctuations. Patent Document 1 also discloses a method for this control that estimates the moisture content of the coal supplied to the coal pulverizer from the heat balance within the mill. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-100740 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention provides a technique for estimating the moisture content of coal without relying on the method disclosed in Patent Document 1.

[0005] The present disclosure provides an estimation device, a coal pulverization device, a plant, an estimation method, and a program that can solve the above-mentioned problems. [Means for solving the problem]

[0006] The estimation device disclosed herein includes an estimation unit that estimates the raw coal moisture content at time t+1, with respect to the raw coal moisture content indicating the moisture content of coal supplied to a coal pulverizer, by adding a value obtained by multiplying a difference between heat input to the coal pulverizer and heat output from the coal pulverizer at time t by a gain to an estimated value of the raw coal moisture content at time t. The estimation device disclosed herein may also include an estimation unit that estimates the raw coal moisture content indicating the moisture content of coal supplied to the coal pulverizer by solving an equation that shows that, when the heat input to the coal pulverizer and the heat output from the coal pulverizer are balanced, the value of the heat input calculation formula is equal to the value of the heat output calculation formula that includes the raw coal moisture content as a variable.

[0007] A coal pulverization device according to the present disclosure includes a mill that pulverizes coal, the estimation device described above, and a control device that controls the mill based on the moisture content of raw coal estimated by the estimation device.

[0008] The estimation method disclosed herein estimates the raw coal moisture content at time t+1, with respect to the raw coal moisture content indicating the moisture content of coal supplied to a coal pulverizer, by adding a value obtained by multiplying a difference between the heat input to the coal pulverizer and the heat output from the coal pulverizer at time t by a gain to an estimated value of the raw coal moisture content at time t. Furthermore, the estimation method disclosed herein may estimate the raw coal moisture content indicating the moisture content of coal supplied to the coal pulverizer by solving an equation showing that, when the heat input to the coal pulverizer and the heat output from the coal pulverizer are balanced, the value of the heat input calculation formula is equal to the value of the heat output calculation formula which includes the raw coal moisture content as a variable.

[0009] The program disclosed herein causes a computer to function as means for estimating the raw coal moisture content at time t+1, with respect to the raw coal moisture content indicating the moisture content of coal supplied to a coal pulverizer, by adding a value obtained by multiplying a difference between heat input to the coal pulverizer and heat output from the coal pulverizer at time t by a gain to an estimated value of the raw coal moisture content at time t. The program disclosed herein may also cause a computer to function as means for estimating the raw coal moisture content indicating the moisture content of coal supplied to the coal pulverizer by solving an equation showing that, when the heat input to the coal pulverizer and the heat output from the coal pulverizer are balanced, the value of the heat input calculation formula is equal to the value of the heat output calculation formula that includes the raw coal moisture content as a variable. [Effects of the Invention]

[0010] According to the above-described estimation device, coal pulverization device, plant, estimation method, and program, the moisture content of coal can be estimated. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram illustrating an example of a coal pulverizer according to an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of estimation logic for the moisture content of raw coal according to the embodiment. [Figure 3A] FIG. 1 is a first diagram showing an example of estimation logic for drying efficiency according to the embodiment. [Figure 3B] FIG. 2 is a second diagram showing an example of estimation logic for drying efficiency according to the embodiment. [Figure 4] 3 is a flowchart showing an example of a process for estimating the moisture content, etc., of raw coal according to the embodiment. [Figure 5] 1 is a first diagram illustrating an example of a plant including a coal pulverizer according to an embodiment. [Figure 6] FIG. 2 is a second diagram illustrating an example of a plant including a coal pulverizer according to an embodiment. [Figure 7] FIG. 2 is a diagram illustrating an example of a hardware configuration of a control device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, the method for estimating the moisture content of raw coal and the moisture content of pulverized coal according to this embodiment will be described with reference to the drawings. <Embodiment> (composition) FIG. 1 is a schematic diagram of a coal pulverizer 100. The coal pulverizer 100 is a mill that pulverizes coal and outputs the pulverized coal to a boiler, power generation facility, or the like. As shown in the figure, the coal pulverizer 100 includes a mill 1 and a control device 10 that controls the mill 1. The mill 1 includes a fuel supply unit 2, a classifier 3, a rotary table 4, a table motor 5, rollers 6, a roller motor 6a, a housing 9 that accommodates these components, a gas flow path 7, and a pulverized coal supply flow path 8. The fuel supply unit 2 is attached vertically so as to penetrate the upper end of the housing 9. Coal (raw coal) is fed into the upper end of the fuel supply unit 2 from a coal feeder (not shown). The fed coal is supplied onto the rotary table 4 through the fuel supply unit 2. The rotary table 4 is provided at the bottom of the housing 9 and rotated by the table motor 5. A roller 6 that presses against the upper surface of the rotary table 4 is provided in the housing 9. The rollers 6 are rotated by a roller motor 6a. Coal supplied to the turntable 4 is guided toward the outer periphery by the rotation of the turntable 4 and is crushed by being caught between the table 4 and the rollers 6. An inlet 7e is provided below the turntable 4, through which a carrier gas is blown in. A gas flow path 7 is connected to the inlet 7e, and the carrier gas is supplied through the gas flow path 7. The carrier gas blown in through the inlet 7e rises within the housing 9. The pulverized coal crushed by the rollers 6 is lifted upward by the carrier gas and guided to the classifier 3. Of the pulverized coal guided to the classifier 3, particles larger than a predetermined particle size are either classified by the classifier 3 or fall back to the turntable 4 without reaching the classifier 3. The remaining pulverized coal rises further within the housing 9 and is discharged from a coal outlet 8a provided at the top of the housing 9 through a pulverized coal supply flow path 8 to other equipment requiring pulverized coal. The carrier gas transports the pulverized coal upward and dries the pulverized coal within the housing 9. The carrier gas is a mixture of high-temperature gas supplied through the high-temperature gas passage 7a and low-temperature gas supplied through the low-temperature gas passage 7b. High-temperature gas heated by, for example, a heat exchanger is supplied to the high-temperature gas passage 7a.A damper 7c is provided in the high-temperature gas flow path 7a, and the opening of this damper 7c is adjusted by the control device 10. Outside air, for example, is supplied to the low-temperature gas flow path 7b. A damper 7d is provided in the low-temperature gas flow path 7b, and the opening of this damper 7d is adjusted by the control device 10. The temperature and flow rate of the carrier gas are appropriately adjusted by controlling the dampers 7c and 7d.

[0013] The mill 1 is provided with sensors 21, 71, 73, 75, 81, and 91 that measure temperature, and sensors 22, 72, 74, and 82 that measure the flow rates and supply amounts of gas and coal. Sensor 21 measures the temperature of the coal supplied to the fuel supply unit 2. This temperature is called the raw coal temperature. Sensor 71 measures the temperature of the high-temperature gas supplied through the high-temperature gas flow path 7a. This temperature is called the high-temperature gas temperature. Sensor 73 measures the temperature of the low-temperature gas supplied through the low-temperature gas flow path 7b. This temperature is called the low-temperature gas temperature. Sensor 75 measures the temperature of the gas (a mixture of high-temperature gas and low-temperature gas) supplied through the gas flow path 7. This temperature is called the mill inlet temperature. Sensor 81 measures the temperature of the gas mixed with pulverized coal flowing through the pulverized coal supply flow path 8. This temperature is called the mill outlet temperature. Sensor 91 measures the atmospheric temperature. The temperatures measured by sensors 21, 71, 73, 81, and 91 are sent to the control device 10. Sensor 22 measures the amount of coal supplied to the fuel supply unit 2. This amount of supply is called the coal feed amount. Sensor 72 measures the flow rate of high-temperature gas supplied through high-temperature gas flow path 7a. This flow rate is called the high-temperature gas flow rate. Sensor 74 measures the flow rate of low-temperature gas supplied through low-temperature gas flow path 7b. This flow rate is called the low-temperature gas flow rate. Sensor 82 measures the output amount (discharge amount) of pulverized coal flowing through the pulverized coal supply flow path 8. The measurement values ​​measured by sensors 22, 72, 74, and 82 are sent to control device 10.

[0014] The control device 10 controls the mill 1 using values ​​measured by the above-mentioned sensors 21 and the like. The control device 10 includes an estimation unit 11 and a control unit 12. The estimation unit 11 estimates the raw coal moisture content, which is the percentage of moisture contained in coal supplied from the fuel supply unit 2, the pulverized coal moisture content, which is the percentage of moisture contained in coal supplied to other devices through the pulverized coal supply passage 8, and the coal drying efficiency in the mill 1. The control unit 12 controls the operation of the coal pulverizer 100 using the raw coal moisture content, etc. estimated by the estimation unit 11. For example, the control unit 12 controls the raw coal supply rate and the rotation speed of the turntable 4 based on the load of the pulverized coal supply destination, the raw coal moisture content, etc., to control the pulverized coal supply rate. The control unit 12 also adjusts the openings of the dampers 7c and 7d.

[0015] Next, a method by which the estimation unit 11 estimates the moisture content of raw coal, the moisture content of pulverized coal, and the drying efficiency will be described with reference to Figures 2 to 3B. Figure 2 shows an outline of the estimation logic by the estimation unit 11. The estimation unit 11 estimates the coal drying efficiency based on, for example, the coal feed rate measured by sensor 22, the mill outlet temperature measured by sensor 81, the mill inlet temperature measured by sensor 75, and a regression model 111.

[0016] As shown in FIG. 3A, regression model 111 is a fixed constant equation calculated by multiple regression analysis or the like using the coal feed rate, mill outlet temperature, and mill inlet temperature as explanatory variables and drying efficiency as a response variable. Conventionally, drying efficiency has been estimated by correcting the standard drying efficiency (design value) of coal pulverizer 100 with the mill inlet temperature, mill outlet temperature, A / C (the ratio of air and gas flow rate to coal flow rate), and the like. In contrast, in this embodiment, the drying efficiency is calculated in advance using a conventional method, and the coal feed rate, mill outlet temperature, and mill inlet temperature measured with coal pulverizer 100 in a state corresponding to the calculated drying efficiency are recorded. Multiple regression analysis is then performed on the relationship between the coal feed rate, mill outlet temperature, mill inlet temperature, and drying efficiency to calculate regression model 111. By calculating regression model 111 in advance, drying efficiency can be calculated online by inputting the actual measured values ​​of the coal feed rate, mill outlet temperature, and mill inlet temperature into regression model 111.

[0017] Note that the regression model for calculating drying efficiency is not limited to the example shown in FIG. 3A. An example of a regression model is shown in FIG. 3B. Item 1 in the table of FIG. 3B is an example in which the coal feed rate, mill outlet temperature, and mill inlet temperature are the explanatory variables, and drying efficiency is the response variable. Item 2 is an example in which a regression model is constructed using A / C (the ratio of air and gas flow rates to the coal flow rate), mill outlet temperature, and mill inlet temperature as explanatory variables, and drying efficiency as the response variable. A / C can be obtained, for example, by dividing the sum of the high-temperature gas flow rate measured by sensor 72 and the low-temperature gas flow rate measured by sensor 74 by the coal feed rate measured by sensor 22. Item 3 is an example in which a regression model is constructed using the coal feed rate as the explanatory variable and drying efficiency as the response variable. Item 4 is an example in which a regression model is constructed using the mill heat input as the explanatory variable and drying efficiency as the response variable. A method for calculating the mill heat input will be described later. Item 5 is an example in which a regression model is constructed using the relative humidity in the mill 1 as the explanatory variable and drying efficiency as the response variable.

[0018] 2, the estimation unit 11 calculates the moisture content of pulverized coal from the drying efficiency, the moisture content of raw coal, and a calculation formula 122. Here, when the moisture content of pulverized coal is Mp (%), the drying efficiency is ηd (%), and Xc is the moisture content of raw coal (%), the moisture content of pulverized coal Mp can be calculated by the following formula 122.

[0019]

number

[0020] As shown in FIG. 2, the estimation unit 11, assuming that the heat balance within the mill 1 is balanced, corrects the raw coal moisture content Xc using the difference between the mill heat input (heat input to the mill 1) and the mill heat output (heat output from the mill 1) to successively estimate the raw coal moisture content Xc for a predetermined time ahead. More specifically, as shown in FIG. 2, the raw coal moisture content Xc(t) calculated at time t is added to the difference between the mill heat input and the mill heat output (mill heat input - mill heat output) at time t multiplied by a predetermined gain Ck to calculate the raw coal moisture content Xc(t+1) for the next time t+1. By repeating this procedure and applying corrections based on the heat balance difference, changes in the raw coal moisture content Xc can be estimated. The mill heat input can be calculated from (1) the raw coal heat input, (2) the inlet gas heat input, and (3) the motor friction heat. The mill heat output can be calculated from (4) the pulverized coal heat output, (5) the outlet gas heat output, (6) the latent heat of vaporization, and (7) miscellaneous losses. A more detailed method for calculating the moisture content Xc of raw coal is shown below.

[0021] The heat balance calculation formula for Mill 1 is shown below.

[0022]

number

[0023] where Mc (kg / h) is the amount of raw coal, Ma (kg / h) is the flow rate of high-temperature gas, Ms (kg / h) is the flow rate of low-temperature gas, Mo (kg / h) is the amount of exhaust coal, Tc (°C) is the raw coal temperature, Ta (°C) is the high-temperature gas temperature, Ts (°C) is the low-temperature gas temperature, To (°C) is the mill outlet temperature, Tt (°C) is the atmospheric temperature, Cc (kcal / kg°C) is the specific heat of raw coal, Ca (kcal / kg°C) is the specific heat of high-temperature gas, Cs (kcal / kg°C) is the specific heat of low-temperature gas, Km (kcal / kg) is the frictional heat constant, Xc (%) is the moisture content of raw coal, ηd (%) is the drying efficiency, Δh (kcal / kg) is the enthalpy difference of the latent heat of vaporization, am (kcal / m 2 H℃) is the heat transfer coefficient from inside the mill, Fm(m 2 ) is the heat transfer area for heat dissipation from inside the mill, and Cma (kcal / ℃) is the heat capacity of mill 1.

[0024] The measurement value of sensor 22 can be applied to Mc, the measurement value of sensor 72 to Ma, the measurement value of sensor 74 to Ms, and the measurement value of sensor 82 to Mo. The measurement value of sensor 21 can be applied to Tc, the measurement value of sensor 71 to Ta, the measurement value of sensor 73 to Ts, the measurement value of sensor 81 to To, and the measurement value of sensor 91 to Tt. ηd can be calculated by the method described with reference to FIGS. 3A and 3B (or may be calculated by a conventional method). The other values ​​and the gain Ck are set in advance in the estimating unit 11.

[0025] The mill heat input Qin can be calculated using "Mc·Tc·Cc+Ma·Ca·Ta+Ms·Cs·Ts+Mc·Km" in Equation 1. Mc·Tc·Cc corresponds to (1) the raw coal heat input, Ma·Ca·Ta+Ms·Cs·Ts corresponds to (2) the inlet gas heat input, and Mc·Km corresponds to (3) the motor friction heat.

[0026] The mill heat output Qout can be calculated using "-Mo·Co·To-Mc·Xc / 100·ηd / 100×Δh-(Ma+Ms)·Ca·To-am·Fm(To-Tt)" in Equation 1. Mo·Co·To corresponds to (4) pulverized coal heat output, Mc×Xc / 100·ηd / 100×Δh corresponds to (6) latent heat of vaporization, (Ma+Ms)·Ca·To corresponds to (5) outlet gas heat output, and am·Fm(To-Tt) corresponds to (7) miscellaneous losses.

[0027] The estimation unit 11 calculates the heat balance difference ΔQ(t) at time t using the following equation 2, and calculates the raw coal moisture content Xc(t+1) at time t+1 using the following equation 3. ΔQ(t)=Qin(t)-Qout(t) (Formula 2) Xc(t+1)=Xc(t)+Ck·ΔQ(t)···(Formula 3) In this way, the estimation unit 11 sequentially calculates the raw coal moisture content Xc from the actual measurement data and the heat balance equation 1, the equation 2 for calculating the difference between the mill heat input Qin and the mill heat output Qout, and the equation 3 for estimating the raw coal moisture content. Note that a predetermined design value is used as the initial value of the raw coal moisture content Xc.

[0028] In the above explanation, the raw coal moisture content Xc was estimated by successively correcting for the heat balance difference. However, if we assume that the system is always in thermal equilibrium, the raw coal moisture content Xc can be uniquely determined. If we assume that the system is in thermal equilibrium, then in the above equation 1, Cma·d / dTo = 0. Furthermore, the amount of discharged coal Mo can be calculated using the following equation 4.

[0029]

number

[0030] From these facts, if it is assumed that the system is in a state of thermal equilibrium, the moisture content Xc of the raw coal can be calculated using the measured values ​​of the sensor 21 and the like and the following equation 5.

[0031]

number

[0032] The estimation unit 11 calculates the pulverized coal moisture content Mp using the above-mentioned formula 122 from the raw coal moisture content Xc and the drying efficiency ηd estimated using formula 3 or formula 5. The drying efficiency ηd may be calculated using a fixed constant formula obtained from multiple regression analysis by the method using Figures 3A and 3B, or the drying efficiency ηd calculated by a conventional method (a value obtained by correcting the standard drying efficiency of the coal pulverizer 100 with the mill inlet temperature, the mill outlet temperature, etc.) may be used.

[0033] (operation) Next, a method for estimating the raw coal moisture content Xc and the pulverized coal moisture content Mp according to this embodiment will be described with reference to Fig. 4. Fig. 4 is a flowchart showing an example of a process for estimating the raw coal moisture content, etc., by the estimation unit 11. The estimation unit 11 acquires the measurement values ​​measured by the sensors 21, 22, 71, 72, 73, 74, 75, 81, and 82 (step S11). Next, the estimation unit 11 estimates the drying efficiency ηd (step S12). For example, the estimation unit 11 inputs the coal feed rate, the mill inlet temperature, and the mill outlet temperature into a regression model 111 to estimate the drying efficiency ηd. The estimation unit 11 may also estimate the drying efficiency ηd by inputting the A / C, the mill outlet temperature, and the mill inlet temperature into the regression model, or may estimate the drying efficiency ηd by inputting the drying efficiency, the mill heat input, or the mill relative humidity into the regression model. Alternatively, the estimation unit 11 may calculate the drying efficiency ηd using a conventional method.

[0034] Next, the estimation unit 11 estimates the raw coal moisture content Xc (step S13). For example, the estimation unit 11 estimates the raw coal moisture content Xc using the above-mentioned formula 3. Alternatively, when the heat balance within the mill 1 is in thermal equilibrium, the estimation unit 11 estimates the raw coal moisture content Xc using formula 5.

[0035] Next, the estimation unit 11 estimates the pulverized coal moisture content Mp (step S14). For example, the estimation unit 11 calculates the pulverized coal moisture content Mp using Equation 122, the drying efficiency ηd estimated in step S12, and the raw coal moisture content Xc estimated in step S13. The estimation unit 11 outputs the estimated pulverized coal moisture content Mp and raw coal moisture content Xc to the control unit 12. The control unit 12 controls the mill 1 based on the estimated values ​​of the pulverized coal moisture content Mp and raw coal moisture content Xc.

[0036] (effect) As described above, according to this embodiment, the moisture content of the coal fed into the mill 1 (raw coal moisture content Xc), which conventionally could only be determined by prior measurement, can be estimated from the heat balance difference within the mill 1. Furthermore, the moisture content Mp of the pulverized coal output from the mill 1 can also be estimated by assuming the drying efficiency ηd. The drying efficiency ηd can also be estimated from various operational information measured by the sensor 21, etc. The estimation unit 11 according to this embodiment can be used as a software sensor for the raw coal moisture content Xc, the pulverized coal moisture content Mp, and the drying efficiency ηd. Furthermore, the raw coal moisture content Xc cannot be measured frequently during operation of the coal pulverizer 100. While the raw coal moisture content measured in advance may deviate from the actual value during operation, the estimation unit 11 according to this embodiment can accurately estimate the raw coal moisture content Xc, the pulverized coal moisture content Mp, and the drying efficiency ηd online at every moment during operation of the coal pulverizer 100. By accurately estimating the moisture content Xc of the raw coal, the controllability of the coal pulverizer 100 can be improved.

[0037] <Application to a plant> FIG. 5 shows a schematic configuration of a boiler system 200 including a coal pulverizer 100. The boiler system 200 includes the coal pulverizer 100 and a boiler 201. The boiler 201 is equipped with a furnace 202 and a burner unit 203. Pulverized coal generated by the coal pulverizer 100 is supplied to the burner unit 203 of the boiler 201 through the pulverized coal supply passage 8. In the boiler 201, the pulverized coal is combusted in the burner unit 203 to generate steam. For example, the boiler 201 supplies the generated steam to a steam turbine (not shown), which then drives a generator (not shown) to generate electricity. The combustion gas discharged from the boiler 201 is guided to a heat exchanger and exchanges heat with outside air in the heat exchanger to heat the outside air and generate high-temperature gas. This high-temperature gas can then be supplied to the high-temperature gas passage 7a. By estimating the raw coal moisture content Xc and the pulverized coal moisture content Mp using the estimation method according to this embodiment and controlling the coal pulverizer 100, it is possible to accurately supply the pulverized coal required by the boiler 201 (power generation load).

[0038] FIG. 6 shows a schematic configuration of an integrated coal gasification combined cycle (IGCC) power plant 300. The integrated coal gasification combined cycle power plant 300 includes a coal pulverizer 100, a gasifier 305, a char recovery system (not shown), a gas purification system 306, a gas turbine 307, a steam turbine 308, a generator 309, a condenser 310, and a heat recovery boiler 311. Pulverized coal discharged from the coal pulverizer 100 through the pulverized coal supply passage 8 is supplied to a pulverized coal dust collector 301. In the pulverized coal dust collector 301, the gas components of the carrier gas are separated from the pulverized coal, and the gas components are pressure-fed by a blower 302 and supplied to the heat recovery boiler 311. The pulverized coal is supplied to a bin 303 and a hopper 304. The pulverized coal recovered in the hopper 304 is supplied to the gasifier 305. The gasifier equipment 305 burns pulverized coal to generate generated gas and sends the generated gas to the gas purification equipment 306. The gas purification equipment 306 removes impurities from the generated gas to generate fuel gas, which is supplied to the gas turbine 307. The combustion of the fuel gas drives the gas turbine 307 to rotate. The exhaust gas from the gas turbine 307 is supplied to the heat recovery steam generator 311. The heat recovery steam generator 311 generates steam by heat exchange between the exhaust gas and feedwater from the condenser 310. The generated steam is supplied to the steam turbine 308. The steam supplied from the heat recovery steam generator 311 drives the steam turbine 308 to rotate. The operation of the gas turbine 307 and the steam turbine 308 drives the generator 309 to rotate and generate electricity. By estimating the moisture content Xc of raw coal and the moisture content Mp of pulverized coal using the estimation method according to this embodiment and controlling the coal pulverizer 100, it is possible to accurately supply the pulverized coal required by an integrated coal gasification combined cycle (IGCC) plant.

[0039] 7 is a diagram showing an example of the hardware configuration of a control device according to an embodiment. A computer 900 includes a CPU 901, a main storage device 902, an auxiliary storage device 903, an input / output interface 904, and a communication interface 905. The above-described control device 10 is implemented in the computer 900. The above-described 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 into the main storage device 902, and executes the above-described processing in accordance with the program. The CPU 901 also allocates a storage area in the main storage device 902 in accordance with the program. The CPU 901 also allocates a storage area in the auxiliary storage device 903 for storing data being processed in accordance with the program.

[0040] A program for implementing all or part of the functions of the control device 10 may be recorded on a computer-readable recording medium, and the program may be loaded 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. Furthermore, if a WWW system is used, the term "computer system" also includes a homepage provision environment (or display environment). Furthermore, the term "computer-readable recording medium" refers to portable media such as CDs, DVDs, and USBs, as well as storage devices such as hard disks built into the computer system. Furthermore, if the program is distributed to the computer 900 via a communication line, the computer 900 that receives the program may load the program into the main storage device 902 and execute the above-described processing. Furthermore, the program may be for implementing part of the above-described functions, or may be capable of implementing the above-described functions in combination with a program already stored in the computer system.

[0041] 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 spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as defined in the claims, as well as in the scope and spirit of the invention.

[0042] <Additional Notes> The estimation device, coal pulverizer, plant, estimation method, and program described in each embodiment can be understood, for example, as follows.

[0043] (1) The estimation device (estimation unit 11) according to the first aspect includes an estimation unit that estimates the moisture content of raw coal at time t+1 by adding a value obtained by multiplying a difference between heat input to the coal pulverizer and heat output from the coal pulverizer at time t by a gain to the estimated value of the moisture content of raw coal at time t, the moisture content indicating the moisture content of coal supplied to the coal pulverizer. This allows the moisture content of the raw coal to be estimated.

[0044] (2) The estimation device according to the second aspect is the estimation device of (1), in which Mc is the amount of raw coal, Ma is the high-temperature gas flow rate, Ms is the low-temperature gas flow rate, Mo is the amount of exhaust coal, Tc is the raw coal temperature, Ta is the high-temperature gas temperature, Ts is the low-temperature gas temperature, To is the mill outlet temperature, Tt is the atmospheric temperature, Cc is the raw coal specific heat, Ca is the high-temperature gas specific heat, Cs is the low-temperature gas specific heat, Km is the frictional heat constant, Xc is the raw coal moisture content, ηd is the drying efficiency, Δh is the enthalpy difference of the latent heat of vaporization, am is the mill If the heat transfer coefficient for heat dissipation from the inside is Fm, the heat transfer area for heat dissipation from inside the mill, and Cma the heat capacity of the mill, then ΔQ(t) is calculated using Mc·Tc·Cc+Ma·Ca·Ta+Ms·Cs·Ts+Mc·Km-Mo·Co·To-Mc·Xc / 100·ηd / 100×Δh-(Ma+Ms)·Ca·To-am·Fm(To-Tt), and the raw coal moisture content Xc is calculated using Xc(t+1)=Xc(t)+Ck·ΔQ(t). This allows the moisture content of the raw coal to be estimated.

[0045] (3) In the estimation device according to the third aspect, the estimation unit estimates the raw coal moisture content, which indicates the moisture content of coal supplied to a coal pulverizer, by solving equation (Equation 5), which indicates that when the heat input and the heat output are in equilibrium, the value of the heat input calculation formula is equal to the value of the heat output calculation formula, which includes the raw coal moisture content as a variable. This allows the moisture content of raw coal to be uniquely estimated.

[0046] (4) The estimation device according to a fourth aspect is the estimation device of (3), wherein the equation is: Mc is the amount of raw coal, Ma is the flow rate of high-temperature gas, Ms is the flow rate of low-temperature gas, Mo is the amount of exhaust coal, Tc is the raw coal temperature, Ta is the high-temperature gas temperature, Ts is the low-temperature gas temperature, To is the mill outlet temperature, Tt is the atmospheric temperature, Cc is the specific heat of raw coal, Ca is the specific heat of high-temperature gas, Cs is the specific heat of low-temperature gas, Km is the frictional heat constant, Xc is the moisture content of raw coal, ηd is the drying efficiency, Δh is the enthalpy difference of the latent heat of evaporation, am is the moisture content of the raw coal in the mill. where m is the heat transfer coefficient of heat dissipation from the inside of the mill, Fm is the heat transfer area for heat dissipation from inside the mill, and Cma is the heat capacity of the mill, when the heat input and the heat output are balanced, the estimation unit estimates the moisture content of the raw coal by {Mc·Tc·Cc+Ma·Ca·Ta+Ms·Cs·Ts+Mc·Km-Mc·Co·To-(Ma+Ms)·Ca·To-am·Fm·(To-Tc)}÷{Mc((ηd·Δh / 100)-(ηd·Co·To / 100))}. This allows the moisture content of raw coal to be uniquely estimated.

[0047] (4) The estimation device according to a fourth aspect is the estimation device of any one of (1) to (4), wherein the heat input is the sum of the heat of the coal supplied to the coal pulverizer, the heat of the gas supplied to the coal pulverizer, and the frictional heat generated by pulverizing the coal in the coal pulverizer, and the heat output is the sum of the heat of the coal discharged from the coal pulverizer, the heat of the gas discharged from the coal pulverizer, the latent heat of vaporization in the coal pulverizer, and the heat released from the coal pulverizer. This allows the moisture content of the raw coal to be estimated.

[0048] (6) An estimation device according to a sixth aspect is an estimation device according to any one of (1) to (5), wherein the estimation unit estimates the drying efficiency based on a model showing the relationship between the amount of coal supplied to the coal pulverizer, the inlet temperature and outlet temperature of the coal pulverizer, and the drying efficiency of the coal, and measured values ​​of the amount of coal supplied, the inlet temperature, and the outlet temperature. This allows the drying efficiency to be estimated.

[0049] (7) An estimation device according to a seventh aspect is an estimation device according to any one of (1) to (6), wherein the estimation unit estimates the drying efficiency based on a model showing the relationship between the ratio of the air supply amount to the coal supply amount supplied to the coal pulverizer, the inlet temperature and outlet temperature of the coal pulverizer, and the drying efficiency of the coal, and the ratio of the air supply amount to the coal supply amount and the measured values ​​of the inlet temperature and outlet temperature. This allows the drying efficiency to be estimated.

[0050] (8) An estimation device according to an eighth aspect is an estimation device according to any one of (1) to (7), wherein the estimation unit estimates the drying efficiency based on a model showing the relationship between the supply amount of coal supplied to the coal pulverizer and the drying efficiency of the coal, and a measured value of the supply amount of coal. This allows the drying efficiency to be estimated.

[0051] (9) An estimation device according to a ninth aspect is an estimation device according to any one of (1) to (8), wherein the estimation unit estimates the drying efficiency based on a model showing the relationship between the heat input to the coal pulverizer and the drying efficiency of the coal and a calculated value of the heat input. This allows the drying efficiency to be estimated.

[0052] (10) An estimation device according to a tenth aspect is an estimation device according to any one of (1) to (9), wherein the estimation unit estimates the drying efficiency based on a model showing the relationship between the relative humidity in the coal pulverizer and the drying efficiency of the coal, and a measured value of the relative humidity. This allows the drying efficiency to be estimated.

[0053] (11) An estimation device according to an eleventh aspect is the estimation device of any one of (1) to (10), wherein the estimation device estimates the pulverized coal moisture content Mp by Mp = {Xc / 100 × (1 - ηd / 100)} ÷ {1 - (Xc / 100 × ηd / 100)}, where Xc is the raw coal moisture content, ηd is the coal drying efficiency in the coal pulverizer, and Mp is the pulverized coal moisture content indicating the moisture content of pulverized coal supplied from the coal pulverizer to an external device. This allows the moisture content of the pulverized coal to be estimated.

[0054] (12) A coal pulverization apparatus according to a twelfth aspect includes a mill for pulverizing coal, an estimation device according to any one of (1) to (11), and a control device for controlling the mill based on the moisture content of raw coal estimated by the estimation device.

[0055] (13) A plant according to a thirteenth aspect includes the coal pulverizer according to (7) and a boiler.

[0056] (14) A plant according to a fourteenth aspect includes the coal pulverizer described in (7), a gasification furnace facility, a gas purification facility, a gas turbine, a steam turbine, a generator, a condenser, and a heat recovery boiler.

[0057] (15) In the estimation method of the fifteenth aspect, the moisture content of raw coal, which indicates the moisture content of coal supplied to a coal pulverizer, is estimated at time t+1 by adding a value obtained by multiplying a difference between heat input to the coal pulverizer and heat output from the coal pulverizer at time t by a gain to the estimated value of the moisture content of the raw coal at time t.

[0058] (16) An estimation method according to a sixteenth aspect estimates the moisture content of raw coal, which indicates the moisture content of coal supplied to a coal pulverizer, by solving an equation that shows that when the heat input to the coal pulverizer and the heat output from the coal pulverizer are balanced, the value of the heat input calculation formula is equal to the value of the heat output calculation formula that includes the moisture content of the raw coal as a variable.

[0059] (17) A program according to a seventeenth aspect causes a computer to function as a means for estimating the moisture content of raw coal at time t+1 by adding a value obtained by multiplying a difference between heat input to the coal pulverizer and heat output from the coal pulverizer at time t by a gain to an estimated value of the moisture content of raw coal at time t, the moisture content indicating the moisture content of coal supplied to the coal pulverizer.

[0060] (16) A program according to a sixteenth aspect causes a computer to function as a means for estimating the moisture content of raw coal, which indicates the moisture content of coal supplied to a coal pulverizer, by solving an equation showing that when the heat input to the coal pulverizer and the heat output from the coal pulverizer are balanced, the value of the heat input calculation formula is equal to the value of the heat output calculation formula which includes the moisture content of the raw coal as a variable. [Explanation of symbols]

[0061] REFERENCE SIGNS LIST 1... mill, 2... fuel supply section, 3... classifying section, 4... rotary table, 5... table motor, 6... roller, 6a... roller motor, 7... gas flow path, 8... pulverized coal supply flow path, 9... housing, 10... control device, 11... estimation section, 12... control section, 21, 22, 71, 72, 73, 74, 75, 81, 82, 91... sensor, 100... coal pulverizer, 200... boiler system, 201... boiler, 202... furnace, 203... burner section, 300... integrated coal gasification combined cycle power generation facility, 301... pulverized coal dust collector, 302... blower, 303... bin, 304 Hopper, 305 Gasification furnace equipment, 306 Gas purification equipment, 307 Gas turbine, 308 Steam turbine, 309 Generator, 310 Condenser, 311 Heat recovery boiler, 900 Computer, 901 CPU, 902 Main storage device, 903 Auxiliary storage device, 904 Input / output interface, 905 Communication interface

Claims

1. Regarding the moisture content of raw coal, which indicates the moisture content of coal fed to the coal crushing device, an estimation unit that estimates the moisture content of the raw coal at time t+1 by adding a value obtained by multiplying a difference between heat input to the coal pulverizer and heat output from the coal pulverizer at time t by a gain to an estimated value of the moisture content of the raw coal at time t; An estimation device comprising:

2. Regarding the moisture content of raw coal, which indicates the moisture content of coal fed to the coal crushing device, an estimation unit that estimates the moisture content of the raw coal by solving an equation that shows that a value of the heat input calculation formula is equal to a value of the heat output calculation formula that includes the moisture content of the raw coal as a variable when the heat input to the coal pulverizer and the heat output from the coal pulverizer are in balance; An estimation device comprising:

3. the heat input is the sum of heat from the coal supplied to the coal pulverizer, heat from the gas supplied to the coal pulverizer, and frictional heat generated by pulverizing the coal in the coal pulverizer; The heat output is the sum of the heat of the coal discharged from the coal pulverizer, the heat of the gas discharged from the coal pulverizer, the latent heat of vaporization in the coal pulverizer, and the heat released from the coal pulverizer. The estimation device according to claim 1 or 2.

4. the estimation unit estimates the drying efficiency based on a model indicating a relationship between the amount of coal supplied to the coal pulverizer, the inlet temperature and the outlet temperature of the coal pulverizer, and the coal drying efficiency, and based on measured values ​​of the amount of coal supplied, the inlet temperature, and the outlet temperature. The estimation device according to claim 1 or 2.

5. the estimation unit estimates the drying efficiency based on a model showing a relationship between a ratio of an air supply amount to an amount of coal supplied to the coal pulverizer, an inlet temperature and an outlet temperature of the coal pulverizer, and the coal drying efficiency, and based on measured values ​​of the ratio of the air supply amount to the amount of coal supplied and the inlet temperature and the outlet temperature; The estimation device according to claim 1 or 2.

6. The estimation device includes: When the moisture content of the raw coal is Xc, the coal drying efficiency in the coal pulverizer is ηd, and the pulverized coal moisture content Mp indicating the moisture content of pulverized coal supplied from the coal pulverizer to an external device is Mp, the pulverized coal moisture content Mp is estimated by Mp = {Xc / 100 × (1 - ηd / 100)} ÷ {1 - (Xc / 100 × ηd / 100)}. The estimation device according to claim 1 or 2.

7. a mill for crushing coal; The estimation device according to claim 1 or 2; a control device that controls the mill based on the moisture content of the raw coal estimated by the estimation device; A coal crushing device comprising:

8. The coal grinding apparatus according to claim 7, a boiler, A plant equipped with:

9. The coal pulverizer according to claim 7, a gasification furnace facility, a gas purification facility, a gas turbine, a steam turbine, a generator, a condenser, and a heat recovery boiler; A plant equipped with:

10. Regarding the moisture content of raw coal, which indicates the moisture content of coal fed to the coal crushing device, a value obtained by multiplying a difference between the heat input to the coal pulverizer and the heat output from the coal pulverizer at time t by a gain and adding the result to the estimated value of the moisture content of the raw coal at time t, thereby estimating the moisture content of the raw coal at time t+1; Estimation method.

11. Regarding the moisture content of raw coal, which indicates the moisture content of coal fed to the coal crushing device, When the heat input to the coal pulverizer and the heat output from the coal pulverizer are in balance, an equation is solved that shows that the value of the heat input calculation formula is equal to the value of the heat output calculation formula that includes the moisture content of the raw coal as a variable, thereby estimating the moisture content of the raw coal. Estimation method.

12. Computer, Regarding the moisture content of raw coal, which indicates the moisture content of coal fed to the coal crushing device, a means for estimating the moisture content of the raw coal at time t+1 by adding a value obtained by multiplying a difference between heat input to the coal pulverizer and heat output from the coal pulverizer at time t by a gain to the estimated value of the moisture content of the raw coal at time t; A program to function as a

13. Computer, Regarding the moisture content of raw coal, which indicates the moisture content of coal fed to the coal crushing device, a means for estimating the moisture content of the raw coal by solving an equation that shows that, when the heat input to the coal pulverizer and the heat output from the coal pulverizer are in balance, the value of the heat input calculation formula is equal to the value of the heat output calculation formula that includes the moisture content of the raw coal as a variable; A program to function as a

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