Operation method for combustion device, selection method for fuel, and operation control system

Abstract

To provide an operation method for a combustion device that is capable of suppressing corrosion inside the combustion device regardless of a type of fuel.SOLUTION: The present invention pertains to an operation method for a combustion device, the operation method comprising a step for detecting ash components where the contents of SiO2, CaO, MgO, Na2O and K2O in ash are defined as RSiO2, RCaO, RMgO, RNa2O and RK2O, a first coefficient m and a second coefficient n are defined, (RSiO2+RCaO+mRMgO+RNa2O+nRK2O) is defined as Rsum, and triangular coordinates are defined using RSiO2 / Rsum as a first coordinate axis, (RCaO+mRMgO) / Rsum as a second coordinate axis, and (RNa2O+nRK2O) / Rsum as a third coordinate axis, the step also being for operating the combustion device so that the composition of the ash is located within a first range surrounded by the first and second coordinate axes and a first boundary line connecting a first position on the first coordinate axis and a second position on the second coordinate axis in the triangular coordinates.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a combustion device operation method, a fuel selection method, and an operation control system. [Background technology]

[0002] Patent Document 1 discloses a combustion control method for burning fuel while suppressing the adhesion of ash to the inside of a combustion furnace or gasification furnace and the concentration of Cl element in the ash. This combustion control method includes a step of detecting the components of the fuel, and a step of calculating the amount of alkali metal volatilization per ash content of the fuel based on the formula (Na2O [wt%] in the ash + 5 × KO2O [wt%] in the ash). 1.6 and supplying a fuel additive having an aluminum oxide / (silicon oxide + aluminum oxide) ratio of 0.25 or more (by weight) to the combustion / gasification furnace when the condition is met, such as × (CaO [wt%] in ash + MgO [wt%] in ash) ≥ 560. This method can suppress the concentration of Cl element in the ash, thereby suppressing corrosion inside the combustion equipment. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2023-095579 Summary of the Invention [Problem to be solved by the invention]

[0004] In the method described in Patent Document 1, the conditions for supplying the additive must be changed depending on the type of fuel (for example, whether the fuel is coal or biomass), and there is a concern that it may be difficult to suppress corrosion inside the combustion device depending on the type of fuel.

[0005] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a combustion apparatus operation method, a fuel selection method, and an operation control system that can suppress corrosion and ash adhesion inside the combustion apparatus regardless of the type of fuel. [Means for solving the problem]

[0006] In order to achieve the above object, a method for operating a combustion device according to at least one embodiment of the present disclosure includes: A method for operating a combustion device that combusts fuel, comprising: Regarding the ash generated by the combustion of the fuel, the contents of SiO2, CaO, MgO, Na2O and K2O in the ash are respectively R SiO2 [wt%], R CaO [wt%] 、 R MgO [wt%], R Na2O [wt%] and R K2O [wt%], and define the first coefficient m, which is a coefficient greater than 0 and less than 5, and the second coefficient n, which is a coefficient greater than 0 and less than 3, and (R SiO2 +R CaO +mR MgO +R Na2O +nR K2O ) to R sum and R sum R SiO2 R is the ratio of SiO2 / R sum is the first coordinate axis, R sum for (R CaO +mR MgO ) is the ratio of (R CaO +mR MgO ) / R sum the second coordinate axis, R sum for (R Na2O +nR K2O ) is the ratio of (R Na2O +nR K2O ) / R sum If we define a triangular coordinate system with the third coordinate axis as The method includes a step of detecting the components of the ash by analyzing the fuel or the ash, and operating the combustion device so that the composition of the ash is located within a first range in the triangular coordinate system, which is surrounded by the first coordinate axis, the second coordinate axis, and a first boundary line connecting a first position on the first coordinate axis that is greater than 0.5 and less than 1, and a second position on the second coordinate axis that is greater than 0.3 and less than 0.8.

[0007] In order to achieve the above object, a method for selecting a fuel for a combustion device according to at least one embodiment of the present disclosure includes: Regarding the ash generated by the combustion of the fuel, the contents of SiO2, CaO, MgO, Na2O and K2O in the ash are respectively R SiO2 [wt%], R CaO [wt%] 、 R MgO [wt%], R Na2O [wt%] and R K2O [wt%], and define the first coefficient m, which is a coefficient greater than 0 and less than 5, and the second coefficient n, which is a coefficient greater than 0 and less than 3, and (R SiO2 +R CaO +mR MgO +R Na2O +nR K2O ) to R sum and R sum R SiO2 R is the ratio of SiO2 / R sum is the first coordinate axis, R sum for (R CaO +mR MgO ) is the ratio of (R CaO +mR MgO ) / R sum the second coordinate axis, R sum for (R Na2O +nR K2O ) is the ratio of (R Na2O +nR K2O ) / R sum If we define a triangular coordinate system with the third coordinate axis as The method includes a step of detecting the ash components by analyzing the fuel or the ash for multiple candidates for the fuel, and selecting as the fuel a candidate whose ash composition is located within a first range in the triangular coordinate system surrounded by the first coordinate axis, the second coordinate axis, and a first boundary line connecting a first position on the first coordinate axis that is greater than 0.5 and less than 1, and a second position on the second coordinate axis that is greater than 0.3 and less than 0.8.

[0008] In order to achieve the above object, an operation control system according to at least one embodiment of the present disclosure includes: An operation control system for a combustion device that burns fuel, Regarding the ash generated by the combustion of the fuel, the contents of SiO2, CaO, MgO, Na2O and K2O in the ash are respectively R SiO2 [wt%], R CaO [wt%] 、 R MgO [wt%], R Na2O [wt%] and R K2O [wt%], and define the first coefficient m, which is a coefficient greater than 0 and less than 5, and the second coefficient n, which is a coefficient greater than 0 and less than 3, and (R SiO2 +R CaO +mR MgO +R Na2O +nR K2O ) to R sum and R sum R SiO2 R is the ratio of SiO2 / R sum is the first coordinate axis, R sum for (R CaO +mR MgO ) is the ratio of (R CaO +mR MgO ) / R sum the second coordinate axis, R sum for (R Na2O +nR K2O ) is the ratio of (R Na2O +nR K2O ) / R sum If we define a triangular coordinate system with the third coordinate axis as a detection unit that detects components of the ash by analyzing the fuel or the ash; an operation control unit that operates the combustion device so that the composition of the ash is located within a first range surrounded by the first coordinate axis, the second coordinate axis, and a first boundary line that connects a first position on the first coordinate axis that is a value greater than 0.5 and less than 1, and a second position on the second coordinate axis that is a value greater than 0.3 and less than 0.8, in the triangular coordinate system; Equipped with. [Effects of the Invention]

[0009] According to at least one embodiment of the present disclosure, there are provided a method for operating a combustion apparatus, a method for selecting a fuel, and an operation control system that can suppress corrosion and ash deposition inside the combustion apparatus regardless of the type of fuel. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of an integrated coal gasification combined cycle power generation facility 10 to which a gasification furnace 101 according to one embodiment is applied. [Figure 2] 2 is a diagram showing an example of the configuration of a gasifier 101 and its surroundings in the integrated coal gasification combined cycle power generation facility 10 shown in FIG. [Figure 3] 2 is a diagram illustrating an example of a hardware configuration of an operation control unit 40. FIG. [Figure 4] 3 is a diagram for explaining an example of an operation control method of the operation control unit 40. FIG. [Figure 5] 3 is a diagram for explaining an example of an operation control method of the operation control unit 40. FIG. [Figure 6] FIG. 10 is a diagram for explaining an example of a fuel selection method. [Figure 7] FIG. 3 is a diagram for explaining an example of a method for determining a fuel mix combustion ratio. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the invention. For example, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement exactly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions representing shapes such as a square shape or a cylindrical shape not only represent shapes such as a square shape or a cylindrical shape in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. On the other hand, the expressions "comprise," "include," "have," "includes," or "have" of one element are not exclusive expressions that exclude the presence of other elements.

[0012] FIG. 1 is a schematic configuration diagram of an integrated coal gasification combined cycle power generation facility 10 to which a gasifier 101 (combustion device) according to an embodiment of the present disclosure is applied. In the following explanation, "upper" refers to the vertically upward direction, and "upper" in terms such as upper part and upper surface refers to the vertically upward part. Similarly, "lower" refers to the vertically downward part, and the vertical direction is not precise and may include errors.

[0013] (Outline of integrated coal gasification combined cycle power generation facility) An integrated coal gasification combined cycle (IGCC) 10 to which a gasifier 101 (combustion device) according to this embodiment is applied uses air as a primary oxidant and employs an air combustion system in which the gasifier 101 produces combustible gas (produced gas) from fuel. The integrated coal gasification combined cycle (IGCC) power plant 10 refines the produced gas produced in the gasifier 101 in a gas refinery 16 to produce fuel gas, which is then supplied to a gas turbine 17 to generate power. That is, the integrated coal gasification combined cycle (IGCC) power plant 10 of this embodiment is an air combustion (air-blown) power plant. Note that, although the present embodiment will be described as an air combustion system, an oxygen combustion (oxygen-blown) system may also be used. The fuel supplied to the gasifier 101 is, for example, a carbon-containing solid fuel such as coal.

[0014] As shown in FIG. 1 , the integrated coal gasification combined cycle power generation facility (integrated gasification combined cycle power generation facility) 10 includes a coal supply facility 11, a gasifier 101, a char recovery facility 15, a gas purification facility 16, a gas turbine 17, a steam turbine 18, a generator 19, and a heat recovery steam generator (HRSG) 20.

[0015] The coal supply facility 11 receives coal, which is a carbon-containing solid fuel, as raw coal and pulverizes the coal using a coal mill (not shown) or the like to produce pulverized coal, which is pulverized into fine particles. The pulverized coal produced by the coal supply facility 11 is pressurized at the outlet of the coal supply line 11a by nitrogen gas, which serves as an inert gas for transportation and is supplied from an air separation facility 42 (described later), and is supplied toward the gasifier 101. The inert gas is an inert gas with an oxygen content of approximately 5% by volume or less, and typical examples include nitrogen gas, carbon dioxide gas, and argon gas, but is not necessarily limited to approximately 5% by volume or less.

[0016] The gasifier 101 is supplied with pulverized coal produced in the coal supply facility 11, and also with char (unreacted coal and ash) recovered in the char recovery facility 15 for the purpose of reusing energy.

[0017] In addition, a compressed air supply line 41 from the gas turbine 17 (compressor 61) is connected to the gasifier 101, and a portion of the compressed air compressed by the gas turbine 17 is boosted to a predetermined pressure by a booster 68 so that it can be supplied to the gasifier 101. The air separation equipment 42 separates and generates nitrogen and oxygen from atmospheric air, and a first nitrogen supply line 43 connects the air separation equipment 42 to a coal feed line 11a from the coal feed equipment 11, and then connects to the gasifier 101 as the fuel supply line 12. In addition, a second nitrogen supply line 45 branching off from the first nitrogen supply line 43 is also connected to a char return line 46 from the char recovery equipment 15, and then connected to the gasifier 101 as the char supply line 13. Furthermore, the air separation equipment 42 is connected to the compressed air supply line 41 by an oxygen supply line 47. The nitrogen separated by the air separation equipment 42 is used as a carrier gas for coal and char by flowing through a first nitrogen supply line 43 and a second nitrogen supply line 45. The oxygen separated by the air separation equipment 42 is used as an oxidizing agent (air, oxygen) in the gasification furnace 101 by flowing through an oxygen supply line 47 and a compressed air supply line 41.

[0018] The gasifier 101 is configured, for example, as a two-stage entrained flow type, and gasifies coal (pulverized coal) and char supplied therein by partial combustion using an oxidizing agent (air, oxygen) to produce a generated gas. The gasifier 101 is provided with a foreign matter removal system 48 that discharges coal, ash (coal ash), and the like to the outside. A first generated gas line 49 that supplies generated gas toward the char recovery system 15 is connected to the gasifier 101, making it possible to discharge the generated gas containing char. In this case, a syngas cooler (gas cooler) (not shown) may be provided in the first generated gas line 49 to cool the generated gas to a predetermined temperature before supplying it to the char recovery system 15.

[0019] The char recovery facility 15 includes a dust collector 51 and a char supply hopper 52. In this case, the dust collector 51 is configured with one or more cyclones or porous filters and can separate char contained in the product gas generated in the gasifier 101. The product gas from which the char has been separated is sent to the gas purification facility 16 through a second product gas line 53. The char supply hopper 52 stores the char separated from the product gas by the dust collector 51. Note that a bin may be disposed between the dust collector 51 and the char supply hopper 52, and multiple char supply hoppers 52 may be connected to this bin. A char return line 46 from the char supply hopper 52 is connected to the second nitrogen supply line 45. Note that in the illustrated exemplary embodiment, a discharge line 59 is provided for extracting a portion of the char (circulating particles) from the char return line 46 or the char supply hopper 52 and discharging it outside the system without passing through the gasifier 101. By actively extracting the char, the Cl concentration rate can be reduced.

[0020] The gas purification equipment 16 purifies the product gas from which char has been separated by the char recovery equipment 15 by removing impurities such as sulfur compounds and nitrogen compounds. The gas purification equipment 16 then purifies the product gas to produce fuel gas, which is supplied to a gas turbine 17. Note that the product gas from which char has been separated contains sulfur compounds (such as H2S), so the gas purification equipment 16 removes and recovers the sulfur compounds using an amine absorption liquid or the like, and then effectively utilizes the sulfur compounds as gypsum or the like.

[0021] The gas turbine 17 includes a compressor 61, a combustor 62, and a turbine 63, and the compressor 61 and the turbine 63 are connected by a rotary shaft 64. A compressed air supply line 65 from the compressor 61, a fuel gas supply line 66 from the gas purification facility 16, and a combustion gas supply line 67 extending toward the turbine 63 are connected to the combustor 62. The gas turbine 17 is also provided with a compressed air supply line 41 extending from the compressor 61 to the gasifier 101, and a booster 68 is provided midway through the line. Therefore, the combustor 62 generates combustion gas by mixing and burning a portion of the compressed air supplied from the compressor 61 and at least a portion of the fuel gas supplied from the gas purification facility 16, and supplies the generated combustion gas to the turbine 63. The turbine 63 rotates the rotary shaft 64 using the supplied combustion gas, thereby rotating the generator 19.

[0022] The steam turbine 18 has a turbine 69 connected to the rotary shaft 64 of the gas turbine 17, and the generator 19 is connected to the base end of this rotary shaft 64. Note that the steam turbine 18 and the gas turbine 17 do not have to be on the same shaft to rotate and drive one generator 19, but may be on different shafts to rotate and drive multiple generators. The exhaust heat recovery boiler 20 is connected to an exhaust gas line 70 from the gas turbine 17 (turbine 63), and generates steam by exchanging heat between water supplied to the exhaust heat recovery boiler 20 and the exhaust gas from the turbine 63.

[0023] A steam supply line 71 and a water supply line 72 are provided between the heat recovery boiler 20 and a turbine 69 of the steam turbine 18, and a condenser 73 is provided on the water supply line 72. The steam generated in the heat recovery boiler 20 may include steam generated by heat exchange with the generated gas in a syngas cooler (not shown) of the gasifier 101. Therefore, in the steam turbine 18, the turbine 69 is rotationally driven by the steam supplied from the heat recovery boiler 20, which rotates the rotary shaft 64 and thereby drives the generator 19. An exhaust gas purification system 74 is provided from the outlet of the heat recovery boiler 20 to the chimney 75.

[0024] Here, the operation of the integrated coal gasification combined cycle power generation facility 10 of this embodiment will be described.

[0025] In the integrated coal gasification combined cycle power generation plant 10 of this embodiment, when raw coal (coal) is supplied to the coal feeding facility 11, the coal is pulverized into fine particles in the coal feeding facility 11 to become pulverized coal. The pulverized coal produced in the coal feeding facility 11 is supplied to the gasifier 101 through the fuel supply line 12 by nitrogen supplied from the air separation facility 42 through the first nitrogen supply line 43.

[0026] Furthermore, char recovered in char recovery equipment 15 (described later) is supplied to gasifier 101 through char supply line 13 by nitrogen supplied from air separation equipment 42 through second nitrogen supply line 45. Furthermore, compressed air extracted from gas turbine 17 (described later) is pressurized by booster 68, and then supplied to gasifier 101 through compressed air supply line 41 together with oxygen supplied from air separation equipment 42.

[0027] In the gasifier 101, the supplied pulverized coal and char are combusted with compressed air (oxygen) and gasified to generate a generated gas. The generated gas is then discharged from the gasifier 101 through a first generated gas line 49 and sent to the char recovery facility 15.

[0028] In this char recovery system 15, the produced gas is first supplied to a dust collector 51, whereby fine char contained in the produced gas is separated. The produced gas from which the char has been separated is then sent to the gas purification system 16 via a second produced gas line 53. Meanwhile, the fine char separated from the produced gas is deposited in a char supply hopper 52 and returned to the gasifier 101 via a char return line 46 for recycling. The gasifier 101, the first produced gas line 49, the char recovery system 15, the char return line 46, and the char supply line 13 constitute a gasification system 103 in which circulating particles (char) circulate.

[0029] The generated gas from which char has been separated in the char recovery facility 15 is purified in the gas purification facility 16 to remove impurities such as sulfur compounds and nitrogen compounds, and fuel gas is produced. A compressor 61 generates compressed air and supplies it to a combustor 62. The combustor 62 generates combustion gas by combusting the compressed air supplied from the compressor 61 with the fuel gas supplied from the gas purification facility 16. The combustion gas rotates a turbine 63, which rotates the compressor 61 and the generator 19 via a rotary shaft 64. In this way, the gas turbine 17 can generate electricity.

[0030] The heat recovery boiler 20 generates steam by exchanging heat between the exhaust gas discharged from a turbine 63 in the gas turbine 17 and water supplied to the heat recovery boiler 20, and supplies the generated steam to the steam turbine 18. In the steam turbine 18, the steam supplied from the heat recovery boiler 20 drives and rotates a turbine 69, which drives and rotates a generator 19 via a rotating shaft 64, thereby generating electricity. Note that the gas turbine 17 and the steam turbine 18 do not have to be on the same shaft and drive and rotate one generator 19, but may be on different shafts and drive and rotate multiple generators.

[0031] Thereafter, in the exhaust gas purification equipment 74, harmful substances in the exhaust gas discharged from the exhaust heat recovery boiler 20 are removed, and the purified exhaust gas is released into the atmosphere from a chimney 75.

[0032] (Gasification furnace) FIG. 2 is a diagram showing an example of the configuration of the gasification furnace 101 and its surroundings in the gasification furnace facility 103 shown in FIG. 2, the gasifier 101 is formed to extend in the vertical direction, and pulverized coal and oxygen are supplied to the lower side in the vertical direction, and the generated gas that is partially combusted and gasified flows from the lower side to the upper side in the vertical direction. The gasifier 101 has a pressure vessel 110 and a gasifier wall (furnace wall) 111 provided inside the pressure vessel 110.

[0033] The gasifier 101 forms an annulus section 115 in the space between the pressure vessel 110 and the gasifier wall 111. The gasifier 101 also forms a combustor section 116, a diffuser section 117, and a reductor section 118 in this order from the lower side in the vertical direction (i.e., from the upstream side in the flow direction of the generated gas) in a space 154 inside the gasifier wall 111.

[0034] The pressure vessel 110 is formed in a cylindrical shape with a hollow space inside, and has a gas outlet at its upper end and a slag hopper 122 at its lower end (bottom). The gasification furnace wall 111 is formed in a cylindrical shape with a hollow space inside, and its outer wall surface is provided opposite the inner wall surface of the pressure vessel 110.

[0035] The gasifier wall 111 separates the interior of the pressure vessel 110 into an internal space 154 and an external space (annulus section 115). The cross-sectional shape of the gasifier wall 111 changes at a diffuser section 117 between a combustor section 116 and a reductor section 118. The gasifier wall 111 has an upper end portion on the vertically upper side connected to the gas outlet of the pressure vessel 110, and a lower end portion on the vertically lower side provided with a gap from the bottom of the pressure vessel 110. A slag hopper 122 formed at the bottom of the pressure vessel 110 stores stored water, and the lower end of the gasifier wall 111 is submerged in the stored water, thereby sealing the inside and outside of the gasifier wall 111. Various burners are inserted into the gasifier wall 111.

[0036] In this embodiment, the combustor section 116 is provided with, for example, multiple char burners 125 and multiple combustor-based pulverized coal burners (burners) 126, which are arranged in this order from the upper side of the furnace, on the gasifier wall 111 in the combustor section 116. A startup combustion chamber below the combustor is equipped with multiple slag melting burners, ignition torches, and diesel burners (not shown). The slag melting burners are used to melt the solidified slag. The tips of the slag melting burners are used to melt and remove the solidified slag. The multiple ignition torches and diesel burners are used to start up the gasifier 101. High-temperature combustion gases generated by burning a portion of the pulverized coal and char in the combustor section 116 pass through the diffuser section 117 and flow into the reductor section 118.

[0037] The reductor section 118 is a space where pulverized coal is supplied to the combustion gas from the combustor section 116, maintained at a high temperature required for the gasification reaction, and where partial oxidation combustion is performed to gasify and decompose the pulverized coal, thereby generating a product gas that is volatile components (carbon monoxide, hydrogen, lower hydrocarbons, etc.), and multiple reductor-system pulverized coal burners (burners) 127 are arranged on the gasifier wall 111 in the reductor section 118. The fuel supply line 12 branches into a combustor-side line 12c and a reductor-side line 12r, and the downstream end of the combustor-side line 12c is connected to the combustor-system pulverized coal burner 126, and the downstream end of the reductor-side line 12r is connected to the reductor-system pulverized coal burner 127.

[0038] (Operation control system) As shown in FIG. 2, the gasification furnace facility 103 includes an operation control system 50 for controlling the operation of the gasification furnace 101. The operation control system 50 includes a detection unit 26, a first additive supply unit 28a, a second additive supply unit 28b, and an operation control unit 40.

[0039] The detection unit 26 is configured to analyze the fuel supplied to the gasification furnace 101 using, for example, an XRF (X-ray fluorescence analyzer) or an ICP-AES (inductively coupled plasma atomic emission spectroscopy (ICP-AES)), and detect the components of ash generated by the combustion of the fuel. The detection unit 26 detects SiO2, Al2O in the ash as the components of the ash generated by the combustion of the fuel. 3、 The detector 26 is configured to detect the contents [wt %] of CaO, MgO, Na2O, and KO, respectively. In the exemplary embodiment shown in Figure 2, the detector 26 is configured to sample fuel from the fuel supply line 12 and detect the above components of the ash.

[0040] The first additive supply unit 28a includes a first additive supply line 29a for supplying the first additive to the fuel, a tank 30a connected to the first additive supply line 29a and storing the first additive, a supply pump 32a for pressurizing and feeding the first additive from the tank 30a, and a supply valve 34a for adjusting the amount of additive supplied. In the illustrated exemplary embodiment, the first additive supply unit 28a is configured to supply the first additive to the reductor unit 118 from a supply port 128a connected to the downstream end of the first additive supply line 29a.

[0041] The first additive includes at least one of SiO2 and AlO2. Of SiO2 and AlO2, the first additive may include only SiO2, may include only AlO2, or may include both SiO2 and AlO2. In some embodiments, the value obtained by dividing the content [wt%] of Al2O3 in the first additive by the content [wt%] of SiO2 in the first additive may be equal to or greater than 0 and equal to 0.25.

[0042] The second additive supply unit 28b includes a second additive supply line 29b for supplying the second additive to the fuel, a tank 30b connected to the second additive supply line 29b and storing the second additive, a supply pump 32b for pressurizing and feeding the second additive from the tank 30b, and a supply valve 34b for adjusting the amount of additive supplied. In the illustrated exemplary embodiment, the second additive supply unit 28b is configured to supply the second additive to the reductor unit 118 from a supply port 128b connected to the downstream end of the second additive supply line 29b.

[0043] The second additive includes an alkaline earth metal. For example, the second additive may include only CaO out of CaO and MgO, or may include only MgO, or may include both CaO and MgO.

[0044] FIG. 3 is a diagram illustrating an example of the hardware configuration of the operation control unit 40. As shown in FIG. As shown in FIG. 3 , the operation control unit 40 includes, for example, a processor 91, a RAM (Random Access Memory) 92, a ROM (Read Only Memory) 93, a HDD (Hard Disk Drive) 94, an input I / F 96, and an output I / F 98, and is configured using a computer that is connected to these via a bus 95. The operation control unit 40 is configured by the computer executing a program that realizes each function of the operation control unit 40. Each function of the operation control unit 40 described below is realized, for example, by loading a program stored in ROM 93 into RAM 92 and executing it with the processor 91, and by reading and writing data from and to the RAM 92 and ROM 93. The hardware that makes up the operation control unit 40 may be concentrated in one location or may be distributed across multiple locations.

[0045] FIG. 4 is a diagram for explaining an example of an operation control method of the operation control unit 40. In FIG. In FIG. 4, the contents of SiO2, CaO, MgO, Na2O, and K2O in the ash generated by the combustion of fuel in the gasifier 101 are shown as R SiO2[wt%], R CaO [wt%] 、 R MgO [wt%], R Na2O [wt%] and R K2O [wt%], and define the first coefficient m, which is a coefficient greater than 0 and less than 5, and the second coefficient n, which is a coefficient greater than 0 and less than 3, and (R SiO2 +R CaO +mR MgO +R Na2O +nR K2O ) to R sum In addition, in Figure 4, R sum R SiO2 R is the ratio of SiO2 / R sum the first coordinate axis a1, R sum for (R CaO +mR MgO ) is the ratio of (R CaO +mR MgO ) / R sum the second coordinate axis a2, R sum for (R Na2O +nR K2O ) is the ratio of (R Na2O +nR K2O ) / R sum A triangular coordinate system T is defined with the third coordinate axis a3 as follows.

[0046] In the example shown in FIG. 4, the first coordinate axis a1 corresponds to the upper left side of the triangular coordinate T, the second coordinate axis a2 corresponds to the upper right side of the triangular coordinate T, and the third coordinate axis a3 corresponds to the bottom side of the triangular coordinate T. In addition, at the lower left vertex of the triangular coordinate T, R SiO2 / R sum is 0, and (R Na2O +nR K2O ) / R sum is 1. Also, at the vertex of the triangular coordinate T, R SiO2 / R sum is 1, and (R CaO +mR MgO ) / R sum is 0. Also, at the bottom right vertex of the triangular coordinate T, (R CaO +mR MgO ) / R sum is 1, and (R Na2O +nR K2O) / R sum is 0.

[0047] In some embodiments, the operation control unit 40 operates the gasifier 101 so that the composition of ash generated by fuel combustion is located within a first range S1 (the dotted hatched area in FIG. 4) surrounded by a first coordinate axis a1, a second coordinate axis a2, and a first boundary line L1 connecting a first position p1 on the first coordinate axis a1, which is a value greater than 0.5 and less than 1, and a second position p2 on the second coordinate axis a2, which is a value greater than 0.3 and less than 0.8, in the triangular coordinate system T shown in FIG. 4. In this case, when the ash composition detected by the detection unit 26 falls outside the first range S1 of the triangular coordinate system T, the operation control unit 40 may control the first additive supply unit 28a to increase the amount of the first additive fed to the reductor unit 118, thereby shifting the ash composition within the first range S1. Specifically, when the ash composition detected by the detection unit 26 falls outside the first range S1 of the triangular coordinate T, the operation control unit 40 may shift the ash composition into the first range S1 by increasing the output of the supply pump 32a and / or increasing the valve opening of the supply valve 34a.

[0048] In the example shown in FIG. 4, the value of the first position p1 on the first coordinate axis a1 is greater than the value of the second position p2 on the second coordinate axis a2. Also, in the example shown in FIG. 4, the value of the first position p1 on the first coordinate axis a1 is greater than 0.7 and less than 0.9, and the value of the second position p2 on the second coordinate axis a2 is greater than 0.3 and less than 0.7. The first boundary line L1 functions as a threshold for suppressing the volatilization of Na and K compounds under typical operating conditions of the reductor section 118 to an acceptable level (a level at which corrosion of the interior of the combustion device due to concentration of Cl in the ash does not become a problem). That is, the first boundary line L1 is defined based on the vapor pressure characteristics of Na and K compounds and serves as a boundary line for determining whether the volatilization of Na and K compounds under typical operating conditions of the reductor section 118 is below an acceptable level (a level at which corrosion of the interior of the combustion device due to concentration of Cl in the ash does not become a problem).

[0049] The technical significance of the above-described operation control by the operation control unit 40 will be described below. In conventional combustion equipment, sodium and potassium compounds (mainly NaOH and KOH) volatilized during the combustion of fuel (e.g., carbon-containing solid fuels such as coal and biomass) condense from the gas phase as the temperature drops, causing ash deposition inside the combustion equipment, raising concerns about adverse effects on the operation of the combustion equipment. Furthermore, when the fuel contains a large amount of Cl, or in combustion equipment with particle circulation such as gasification furnaces, the sodium and potassium compounds volatilized during fuel combustion react with HCl in the gas to produce chlorides, and the chlorides in the deposited ash can cause ash deposition inside the combustion equipment, increasing the risk of deposition problems and corrosion.

[0050] For example, in a gasifier, NaOH and KOH that volatilize in the combustor section react with SiO2, Al2O3, etc. and are fixed to particles to produce Na2O-SiO2-Al2O3 and K2O-SiO2-Al2O3, etc., and the remaining NaOH and KOH that are not fixed react with HCl to produce NaCl and KCl. These NaCl and KCl are recovered in char recovery equipment 15 and returned to the combustor section as char, so Cl becomes concentrated in the ash, which is likely to increase the risk of corrosion inside the gasifier.

[0051] Therefore, in order to suppress corrosion caused by Cl in the fuel, it is important to suppress the volatilization of sodium and potassium compounds in the combustion equipment to an appropriate level. In this regard, the SiO2 component of the ash has the effect of suppressing the volatilization of sodium and potassium compounds, while the CaO, MgO, Na2O, and K2O components have the effect of promoting the volatilization of sodium and potassium compounds, and the degree of influence on each effect varies depending on the component.

[0052] Therefore, in the above-described operation control by the operation control unit 40, the first coefficient m and the second coefficient n are set in consideration of the degree of influence of each component of ash on the suppression and promotion of the volatilization phenomenon of alkali metal compounds (Na compounds and K compounds), the first boundary line L1 is set, which functions as a threshold for suppressing the volatilization phenomenon of Na compounds and K compounds under typical operating conditions of the reductor unit 118 to an allowable level (a level at which corrosion inside the combustion device due to concentration of Cl in the ash does not become a problem), and the gasifier 101 is operated so that the composition of ash generated by fuel combustion is located within the first range S1 of the triangular coordinate T. This suppresses the volatilization phenomenon of Na compounds and K compounds to an allowable level or below, suppresses concentration of Cl in the ash, and makes it possible to suppress corrosion inside the gasifier 101 regardless of the type of fuel.

[0053] Furthermore, when the composition of ash generated by fuel combustion deviates from the first range S1 of the triangular coordinate T, the gasifier 101 can be operated so that the ash composition falls within the first range S1 of the triangular coordinate T by increasing the amount of the first additive fed to the gasifier 101. Furthermore, when the composition of ash generated by fuel combustion deviates from the first range S1 of the triangular coordinate T, the NaOH gas and KOH gas generated in the combustor section 116 of the gasifier 101 quickly react with the first additive by increasing the amount of the first additive fed to the reductor section 118. This reduces the amount of NaCl gas generated by the reaction between NaOH gas and HCl gas and the amount of KCl gas generated by the reaction between KOH gas and HCl gas in the reductor section 118. This reduces Cl in the ash adhering downstream of the reductor section 118, thereby suppressing corrosion inside the gasifier 101.

[0054] In some embodiments, the operation control unit 40 may operate the gasifier 101 so that the composition of ash generated by fuel combustion is located within a second range S2 defined by the second coordinate axis a2, the first boundary line L1, and the second boundary line L2 extending from a third position p3 on the second coordinate axis a2 that is greater than 0 and less than the second position p2 so as to intersect with the first boundary line L1 in the triangular coordinate system T shown in Fig. 4. In this case, when the ash composition detected by the detection unit 26 deviates from the second range S2 of the triangular coordinate system T toward the first coordinate axis a1, the operation control unit 40 may shift the ash composition into the second range S2 by increasing the amount of the second additive fed to the reductor unit 118. Specifically, when the ash composition detected by the detection unit 26 deviates from the second range S2 of the triangular coordinate T toward the first coordinate axis a1 (for example, when it is located in the range surrounded by the first coordinate axis a1, the second coordinate axis a2, the first boundary line L1, and the second boundary line L2), the operation control unit 40 may shift the ash composition into the second range S2 by increasing the output of the supply pump 32b and / or by increasing the valve opening of the supply valve 34b.

[0055] In the example shown in Fig. 4, the value of the third position p3 on the second coordinate axis a2 is greater than 0.1 and less than 0.4 on the second coordinate axis a2. Also, in the example shown in Fig. 4, the value of the first coordinate axis a1 at position p4 where the first boundary line L1 and the second boundary line L2 intersect is greater than 0.5 and less than 0.8, the value of the second coordinate axis a2 at position p4 is greater than 0.1 and less than 0.4, and the value of the third coordinate axis a3 at position p4 is greater than 0 and less than 0.2.

[0056] According to the operation control unit 40, an isoviscosity line (isoviscosity line of slag) that ensures good dischargeability of liquid-phase slag from the gasification furnace 101 is set as the second boundary line L2, and the gasification furnace 101 is operated so that the ash composition is located within the second range S2, thereby achieving good dischargeability of liquid-phase slag from the gasification furnace 101 while suppressing corrosion inside the gasification furnace.

[0057] Furthermore, when the composition of ash generated by fuel combustion deviates from the second range S2 of the triangular coordinate T toward the first coordinate axis a1, the gasifier 101 can be operated so that the ash composition is within the second range S2 of the triangular coordinate by increasing the amount of the second additive containing alkaline earth metal fed to the gasifier 101. This makes it possible to suppress corrosion inside the gasifier 101 while achieving good dischargeability of liquid-phase slag from the gasifier 101.

[0058] Here, the content of Al2O3 in the ash generated by fuel combustion is R Al2O3 In some embodiments, the operation control unit 40 defines R SiO2 R Al2O3 R is the ratio of Al2O3 / R SiO2 (i.e., R detected by the detection unit 26) SiO2 and R Al2O3 and R calculated using Al2O3 / R SiO2 In other words, the operation control unit 40 may change the first boundary line L1 depending on R Al2O3 / R SiO2 For example, the first range S1 may be changed depending on R Al2O3 / R SiO2 When n1, a first range S1 is defined using a first boundary line L1 shown in FIG. 4, and R Al2O3 / R SiO2 When n2 is smaller than n1, the first boundary line L1 shown in FIG. 5 may be used to define the first range S1. That is, R Al2O3 / R SiO2 The first boundary line L1 may be changed so that the value of the first position p1 on the first coordinate axis a1 increases as R decreases. Al2O3 / R SiO2 The first boundary line L1 may be changed so that as the value of the first position p1 on the first coordinate axis a1 decreases, the value of the second position p2 on the second coordinate axis a2 decreases.

[0059] R Al2O3 / R SiO2 Since R affects the amount of alkali metal volatilization and the degree of Cl concentration in the ash, as mentioned above,Al2O3 / R SiO2 By changing the first boundary line L1 and the first range S1 so that the value of the first position p1 on the first coordinate axis a1 increases as the value of the first boundary line L1 and the first range S1 decreases, the volatilization of Na compounds and K compounds can be kept below an allowable level, the concentration of Cl in the ash can be suppressed, and corrosion inside the combustion device can be suppressed regardless of the type of fuel.

[0060] In some embodiments, the time for contacting the SiO2 with the high-temperature gas in the reductor section 118 may be 3 seconds or longer. This allows the concentrations of the compounds represented by the following reaction formulas (a) and (b) in the reductor section 118 to reach values ​​close to equilibrium concentration, and under typical operating conditions of the reductor section, approximately 70% of the alkali metal in the gas can be fixed to particles, and the Na / K gas can be reduced to 30%. 2KCl+3SiO2+H2O→K2Si3O9+2HCl ···(a) 2NaCl+3SiO2+H2O→Na2Si3O9+2HCl ···(b)

[0061] The present disclosure is not limited to the above-described embodiments, but also includes modifications to the above-described embodiments and appropriate combinations of these modifications.

[0062] For example, in the embodiment shown in FIG. 2, the detection unit 26 detects each component of the ash generated by the combustion of the fuel by analyzing the fuel before it is supplied to the gasification furnace 101 using XRF or the like, but in other embodiments, the detection unit 26 may detect each component of the ash generated by the combustion of the fuel by analyzing the ash generated by the combustion of the fuel in the gasification furnace 101 using XRF or the like.

[0063] For example, in the embodiment shown in FIG. 2, the first additive supply unit 28a supplies the first additive from the supply port 128a to the reductor unit 118, but the first additive supply unit 28a may supply the first additive, for example, to the fuel supply line 12, preferably to the reductor side line 12r of the fuel supply line 12.

[0064] Also, for example, in the embodiment shown in FIG. 2, the second additive supply unit 28b supplies the second additive from the supply port 128b to the reductor unit 118, but the second additive supply unit 28b may supply the second additive to, for example, the fuel supply line 12, preferably to the reductor side line 12r of the fuel supply line 12.

[0065] In some embodiments, when the system is configured to discharge solid slag (dry discharge), such as in a boiler, the value obtained by dividing the Al2O3 content [wt%] in the first additive by the SiO2 content [wt%] in the first additive may be, for example, 0.6 or more and 0.8 or less.

[0066] In some embodiments, as shown in FIG. 6, for multiple candidate fuels A to G to be used in the combustion device, the components of ash generated by the combustion of the fuel (the content [wt%] of at least SiO2, CaO, MgO, Na2O, and KO in the ash) may be detected, and the ash composition of each of the multiple candidates A to G may be plotted on the triangular coordinate T, and a candidate whose ash composition falls within the first range S1 (in the illustrated example, any of fuels A, C, F, and G) may be selected as the fuel to be used in the combustion device.

[0067] Even in this case, the first coefficient m and the second coefficient n are set in consideration of the degree of influence of each component of the ash on the suppressing and promoting effects of the volatilization phenomenon of alkali metal compounds (Na compounds and K compounds), the first boundary line L1 is set so that the volatilization phenomenon of Na compounds and K compounds can be kept below an allowable level (a level at which corrosion inside the combustion apparatus due to concentration of Cl in the ash does not become a problem), and fuel is selected so that the ash composition is located within the first range S1. This makes it possible to suppress the volatilization phenomenon of Na compounds and K compounds below an allowable level and suppress corrosion inside the gasifier 101.

[0068] 6, for multiple candidate fuels A to G used in the combustion device, the ash components (contents [wt%] of at least SiO2, CaO, MgO, Na2O, and KO in the ash) generated by the combustion of the fuel may be detected, and the ash composition of each of the multiple candidates A to G may be plotted on the triangular coordinate T. A candidate whose ash composition falls within the second range S2 (in the illustrated example, either fuel F or G) may be selected as the fuel to be used in the combustion device. This makes it possible to suppress corrosion inside the gasifier while achieving good dischargeability of liquid-phase slag from the gasifier.

[0069] In some embodiments, when a first fuel A and a second fuel B having a different composition from the first fuel A are mixed in a combustion apparatus, the first fuel A is analyzed to detect the components of ash produced by combustion of the first fuel A (the contents [wt%] of at least SiO, CaO, MgO, NaO, and KO in the ash), and the second fuel B is analyzed to detect the components of ash produced by combustion of the second fuel B (the contents [wt%] of at least SiO, CaO, MgO, NaO, and KO in the ash). The first fuel A and the second fuel B may be mixed in a mixed combustion ratio (e.g., α% for fuel A and (100-α)%) determined so that the composition of the ash produced by the mixed combustion falls within the first range S1. This suppresses the volatilization of sodium and potassium compounds within the combustion apparatus below an allowable level, thereby suppressing corrosion within the combustion apparatus regardless of the types of the first and second fuels.

[0070] The contents described in each of the above embodiments can be understood, for example, as follows.

[0071] [1] A method for operating a combustion device according to at least one embodiment of the present disclosure includes: A method for operating a combustion device (e.g., the above-described gasification furnace 101) that combusts fuel, comprising: Regarding the ash generated by the combustion of the fuel, the contents of SiO2, CaO, MgO, Na2O and K2O in the ash are respectively R SiO2 [wt%], R CaO [wt%]、 R MgO [wt%], R Na2O [wt%] and R K2O [wt%], and define the first coefficient m, which is a coefficient greater than 0 and less than 5, and the second coefficient n, which is a coefficient greater than 0 and less than 3, and (R SiO2 +R CaO +mR MgO +R Na2O +nR K2O ) to R sum and R sum R SiO2 R is the ratio of SiO2 / R sum is the first coordinate axis, R sum for (R CaO +mR MgO ) is the ratio of (R CaO +mR MgO ) / R sum the second coordinate axis, R sum for (R Na2O +nR K2O ) is the ratio of (R Na2O +nR K2O ) / R sum If we define a triangular coordinate system with the third coordinate axis as the coordinate (for example, the triangular coordinate system T mentioned above), The method includes a step of detecting the components of the ash by analyzing the fuel or the ash, and operating the combustion device so that the composition of the ash is located within a first range (e.g., the first range S1 described above) surrounded by the first coordinate axis, the second coordinate axis, and a first boundary line (e.g., the first boundary line L1 described above) connecting a first position on the first coordinate axis (e.g., the first position p1 described above) that is greater than 0.5 and less than 1, and a second position on the second coordinate axis (e.g., the second position p2 described above) that is greater than 0.3 and less than 0.8.

[0072] In conventional combustion systems, sodium and potassium compounds (mainly NaOH and KOH) volatilized during fuel combustion condense from the gas phase as the temperature drops, leading to ash deposition inside the combustion system and potentially adversely affecting system operation. Furthermore, when the fuel contains a high concentration of Cl, or when combustion systems involve particle circulation (e.g., IGCC gasification furnaces or boilers with fly ash recycling, where Cl is concentrated in the ash due to particle circulation), the volatilized sodium and potassium compounds react with HCl in the gas to produce chlorides, potentially leading to corrosion inside the combustion system. Meanwhile, the SiO2 component of the ash inhibits the volatilization of sodium and potassium compounds, while CaO, MgO, Na2O, and K2O promote the volatilization of sodium and potassium compounds, with the degree of influence of each component varying.

[0073] Therefore, in the method of operating a combustion apparatus described in [1] above, the first coefficient m and the second coefficient n are set in consideration of the degree of influence of each ash component on the suppression and promotion of the volatilization of alkali metal compounds (sodium compounds and potassium compounds), and the first boundary line is set as a threshold for suppressing the volatilization of sodium compounds and potassium compounds under typical operating conditions of the combustion apparatus to an acceptable level (a level at which corrosion of the interior of the combustion apparatus due to concentration of Cl in the ash does not become a problem), and the combustion apparatus is operated so that the ash composition is located within the first range. This suppresses the volatilization of sodium compounds and potassium compounds to an acceptable level and suppresses corrosion of the interior of the combustion apparatus and ash adhesion, regardless of the type of fuel.

[0074] [2] In some embodiments, in the method for operating the combustion apparatus described in [1] above, The value of the first position on the first coordinate axis is greater than the value of the second position on the second coordinate axis.

[0075] According to the method of operating a combustion apparatus described in [2] above, the volatilization of Na compounds and K compounds can be suppressed to an acceptable level or below, and corrosion inside the combustion apparatus and ash adhesion can be suppressed regardless of the type of fuel.

[0076] [3] In some embodiments, in the method for operating the combustion apparatus according to [1] or [2] above, the first position is a value greater than 0.7 and less than 0.9 on the first coordinate axis, The second position is a value greater than 0.3 and less than 0.7 on the second coordinate axis.

[0077] According to the method of operating a combustion apparatus described in [3] above, the volatilization of Na compounds and K compounds can be suppressed to an acceptable level or below, and corrosion inside the combustion apparatus and ash adhesion can be suppressed regardless of the type of fuel.

[0078] [4] In some embodiments, in the method for operating the combustion apparatus according to any one of [1] to [3] above, The content of Al2O3 in the ash is R Al2O3 If we define it as: In the step, R SiO2 R Al2O3 R is the ratio of Al2O3 / R SiO2 The first boundary line is changed according to the

[0079] R Al2O3 / R SiO2 Since R affects the amount of alkali metal volatilization and the degree of Cl concentration in the ash, as described above in [4], Al2O3 / R SiO2 By changing the first boundary line according to the type of fuel, the volatilization of sodium and potassium compounds can be suppressed to an acceptable level or below, thereby suppressing corrosion inside the combustion equipment and ash adhesion, regardless of the type of fuel.

[0080] [5] In some embodiments, in the method for operating the combustion apparatus described in [4] above, In the step, R Al2O3 / R SiO2 The first boundary line is changed so that the value of the first position increases as the value of the first boundary line decreases.

[0081] R Al2O3 / RSiO2 Since R affects the amount of alkali metal volatilization and the degree of Cl concentration in the ash, as described above in [5], Al2O3 / R SiO2 By changing the first boundary line so that the value of the first position increases as the value of the first boundary line decreases, the volatilization of Na compounds and K compounds can be suppressed to an allowable level or below, and corrosion inside the combustion device and ash adhesion can be suppressed regardless of the type of fuel.

[0082] [6] In some embodiments, in the method for operating the combustion apparatus according to any one of [1] to [5] above, In this step, if the composition of the ash falls outside the first range of the triangular coordinates, the amount of additive (e.g., the first additive described above) containing at least one of SiO2 and AlO2 fed to the combustion device is increased.

[0083] According to the method for operating a combustion apparatus described in [6] above, when the ash composition falls outside the first range of triangular coordinates, the amount of additive containing at least one of SiO2 and AlO2 fed to the combustion apparatus can be increased to operate the combustion apparatus so that the ash composition falls within the first range of triangular coordinates. This suppresses the volatilization of sodium and potassium compounds to an acceptable level and inhibits corrosion inside the combustion apparatus and ash adhesion, regardless of the type of fuel.

[0084] [7] In some embodiments, in the method for operating the combustion apparatus described in [6] above, The combustion device is a gasification furnace of a coal gasification combined cycle power generation system (for example, the above-mentioned gasification furnace 101), In the step, if the composition of the ash falls outside the first range of the triangular coordinates, the amount of the additive fed to the reductor section of the gasifier (for example, the above-mentioned reductor section 118) is increased.

[0085] According to the method of operating a combustion apparatus described in [7] above, by increasing the amount of additives containing at least one of SiO2 and AlO2 fed to the reductor section, the NaOH gas and KOH gas generated in the combustor section of the gasifier react quickly with the additives, thereby reducing the amount of NaCl gas generated by the reaction between NaOH gas and HCl gas in the reductor section and the amount of KCl gas generated by the reaction between KOH gas and HCl gas in the reductor section. This reduces the Cl content in the ash adhering downstream of the reductor section, thereby suppressing corrosion inside the gasifier and ash adhesion.

[0086] [8] In some embodiments, in the method for operating the combustion apparatus according to [6] or [7] above, The combustion device is a gasification furnace of a coal gasification combined cycle power generation system (for example, the above-mentioned gasification furnace 101), The value obtained by dividing the content [wt%] of Al2O3 in the additive by the content [wt%] of SiO2 in the additive is 0 or more and 0.25 or less.

[0087] Since a high Al2O3 content in the additive tends to increase the melting point of the reaction product, as described above in [8], the melting point of the reaction product can be made relatively low by dividing the Al2O3 content [wt%] in the additive by the SiO2 content [wt%] in the additive to a value between 0 and 0.25. This makes it possible to suppress corrosion inside the gasifier and ash adhesion while ensuring the discharge of liquid slag from the gasifier.

[0088] [9] In some embodiments, in the method of operating the combustion apparatus according to any one of [1] to [8] above, The combustion device is a gasification furnace of a coal gasification combined cycle power generation system (for example, the above-mentioned gasification furnace 101), In this step, the combustion device is operated so that the ash composition is located within a second range surrounded by the second coordinate axis, the first boundary line, and a second boundary line (e.g., the above-mentioned second boundary line L2) extending from a third position (e.g., the above-mentioned third position p3) on the second coordinate axis that is greater than 0 and less than the second position so as to intersect with the first boundary line.

[0089] According to the method of operating a combustion device described in [9] above, by setting the second boundary line using an isoviscosity line that can ensure the dischargeability of liquid slag from the gasification furnace, it is possible to suppress corrosion and ash adhesion inside the gasification furnace while achieving good dischargeability of liquid slag from the gasification furnace.

[0090]

[10] In some embodiments, in the method for operating the combustion apparatus described in [9] above, In the step, if the composition of the ash deviates from the second range of the triangular coordinates toward the first coordinate axis, the amount of additive containing an alkaline earth metal (e.g., the second additive described above) fed into the gasification furnace is increased.

[0091] According to the method for operating a combustion apparatus described in

[10] above, when the ash composition deviates from the second range of the triangular coordinates toward the first coordinate axis, the amount of additive containing an alkaline earth metal fed to the gasifier can be increased to operate the combustion apparatus so that the ash composition is within the second range of the triangular coordinates. This makes it possible to suppress corrosion and ash adhesion inside the gasifier while achieving good dischargeability of liquid slag from the gasifier.

[0092]

[11] In some embodiments, in the method for operating the combustion apparatus described in [1] above, The fuel includes a first fuel (for example, the first fuel A described above) and a second fuel (for example, the second fuel B described above) having a different composition from the first fuel, The combustion device is configured to co-combust the first fuel and the second fuel, In the step, the first fuel and the second fuel are mixed and burned at a mixing ratio determined so that the composition of ash produced by mixing the first fuel and the second fuel is located within the first range of the triangular coordinates.

[0093] According to the method of operating a combustion apparatus described in

[11] above, the volatilization of Na compounds and K compounds can be suppressed below an allowable level, and corrosion and ash adhesion inside the combustion apparatus can be suppressed regardless of the types of the first and second fuels.

[0094]

[12] A method for selecting a fuel for a combustion device according to at least one embodiment of the present disclosure includes: A method for selecting fuel for a combustion device (e.g., the gasifier 101 described above), comprising: Regarding the ash generated by the combustion of the fuel, the contents of SiO2, CaO, MgO, Na2O and K2O in the ash are respectively R SiO2 [wt%], R CaO [wt%] 、 R MgO [wt%], R Na2O [wt%] and R K2O [wt%], and define the first coefficient m, which is a coefficient greater than 0 and less than 5, and the second coefficient n, which is a coefficient greater than 0 and less than 3, and (R SiO2 +R CaO +mR MgO +R Na2O +nR K2O ) to R sum and R sum R SiO2 R is the ratio of SiO2 / R sum is the first coordinate axis, R sum for (R CaO +mR MgO ) is the ratio of (R CaO +mR MgO ) / R sum the second coordinate axis, R sum for (R Na2O +nR K2O ) is the ratio of (R Na2O +nR K2O ) / R sumIf we define a triangular coordinate system with the third coordinate axis as the coordinate (for example, the triangular coordinate system T mentioned above), The method includes a step of detecting the ash components by analyzing the fuel or the ash for multiple candidates for the fuel (for example, the above-mentioned candidates A to G), and selecting as the fuel a candidate (for example, any of the above-mentioned candidates A, C, F, and G) whose ash composition is located within a first range surrounded in the triangular coordinate system by the first coordinate axis, the second coordinate axis, and a first boundary line connecting a first position on the first coordinate axis that is greater than 0.5 and less than 1, and a second position on the second coordinate axis that is greater than 0.3 and less than 0.8.

[0095] According to the fuel selection method described in

[12] above, the first coefficient m and the second coefficient n are set in consideration of the degree of influence of each ash component on the suppression and promotion of the volatilization of alkali metal compounds (sodium compounds and potassium compounds), and the first boundary line is set as a threshold for suppressing the volatilization of sodium compounds and potassium compounds under typical operating conditions of a combustion device to an acceptable level (a level at which corrosion of the interior of the combustion device due to concentration of Cl in the ash does not become a problem), and then a fuel is selected so that the ash composition falls within the first range. This suppresses the volatilization of sodium compounds and potassium compounds to an acceptable level and suppresses corrosion of the interior of the combustion device and ash adhesion.

[0096]

[13] An operation control system according to at least one embodiment of the present disclosure includes: An operation control system for a combustion device that combusts fuel (for example, the above-mentioned operation control system 50), Regarding the ash generated by the combustion of the fuel, the contents of SiO2, CaO, MgO, Na2O and K2O in the ash are respectively R SiO2 [wt%], R CaO [wt%] 、 R MgO [wt%], R Na2O [wt%] and R K2O [wt%], and define the first coefficient m, which is a coefficient greater than 0 and less than 5, and the second coefficient n, which is a coefficient greater than 0 and less than 3, and (R SiO2 +RCaO +mR MgO +R Na2O +nR K2O ) to R sum and R sum R SiO2 R is the ratio of SiO2 / R sum is the first coordinate axis, R sum for (R CaO +mR MgO ) is the ratio of (R CaO +mR MgO ) / R sum the second coordinate axis, R sum for (R Na2O +nR K2O ) is the ratio of (R Na2O +nR K2O ) / R sum If we define a triangular coordinate system (such as the triangular coordinate system mentioned above) with the third coordinate axis as a detection unit (for example, the above-mentioned detection unit 26) that detects components of the ash by analyzing the fuel or the ash; an operation control unit (for example, the above-mentioned operation control unit 40) that operates the combustion device so that the composition of the ash is located within a first range (for example, the above-mentioned first range S1) surrounded by the first coordinate axis, the second coordinate axis, and a first boundary line (for example, the above-mentioned first boundary line L1) that connects a first position on the first coordinate axis that is a value greater than 0.5 and less than 1, and a second position on the second coordinate axis that is a value greater than 0.3 and less than 0.8; Equipped with.

[0097] According to the operation control system described in

[13] above, the first coefficient m and the second coefficient n are set in consideration of the degree of influence of each ash component on the suppression and promotion of the volatilization of alkali metal compounds (sodium compounds and potassium compounds), and the first boundary line is set as a threshold for suppressing the volatilization of sodium compounds and potassium compounds under typical operating conditions of the combustion equipment to an acceptable level (a level at which corrosion of the interior of the combustion equipment due to concentration of Cl in the ash does not become a problem), and the combustion equipment is operated so that the ash composition is located within the first range. This makes it possible to suppress the volatilization of sodium compounds and potassium compounds to an acceptable level or below, thereby suppressing corrosion of the interior of the combustion equipment and ash adhesion.

[0098]

[14] In some embodiments, in the driving control system described in

[13] above, The system further includes an additive supply unit (e.g., the first additive supply unit 28a) configured to supply an additive including at least one of SiO2 and AlO2 to the combustion device, The operation control unit controls the additive supply unit to increase the amount of the additive fed to the combustion device when the composition of the ash falls outside the first range of the triangular coordinates.

[0099] According to the operation control system described in

[14] above, when the ash composition falls outside the first range of triangular coordinates, the amount of additive containing at least one of SiO2 and AlO2 fed to the combustion equipment can be increased to operate the combustion equipment so that the ash composition falls within the first range of triangular coordinates. This suppresses the volatilization of sodium and potassium compounds to an acceptable level and inhibits corrosion inside the combustion equipment and ash adhesion, regardless of the type of fuel. [Explanation of symbols]

[0100] 10. Coal gasification combined cycle power generation facility 11 Coal feeding equipment 11a Coal supply line 12 Fuel supply line 12c Combustor side line 12r Reductor side line 13 Char supply line 15 Char recovery facility 16 Gas purification facility 17 Gas Turbine 18 Steam Turbine 19. Generator 20 Waste heat recovery boiler 26 Detector 28a First additive supply section 28b Second additive supply section 29a First additive supply line 29b Second additive supply line 30a, 30b tank 32a, 32b Supply pump 34a, 34b supply valve 40 Operation control unit 41,65 Compressed air supply line 42 Air Separation Plant 43 First nitrogen supply line 45 Second nitrogen supply line 46 Char return line 47 Oxygen supply line 48 Foreign matter removal equipment 49 First produced gas line 50 Driving Control System 51 Dust collector 52 Char supply hopper 53 Second produced gas line 59 Discharge Line 61 Compressor 62 Combustor 63,69 Turbine 64 Rotation Axis 66 Fuel gas supply line 67 Combustion gas supply line 68 Booster 70 Exhaust gas line 71 Steam supply line 72 Water supply line 73 Condenser 74 Exhaust gas purification equipment 75 Chimney 90 Discharge Line 101 Gasifier 103 Gasification furnace equipment 110 Pressure vessels 111 Gasifier wall 115 Annulus 116 Combustor Club 117 Diffuser section 118 Reductor section 122 Slag Hopper 125 Charvana 126 Combustor-type pulverized coal burner 127 Reductor-type pulverized coal burner 128a, 128b supply ports 154 Interior Space A, B, C, F, G fuel candidates L1 1st boundary L2 2nd border S1 First range S2 Second range T triangular coordinates a1 First coordinate axis a2 Second coordinate axis a3 Third coordinate axis m First coefficient n second coefficient p1 1st position p2 2nd position p3 3rd position p4 position 90 processors 91 RAM 92 ROM 94 HDD 95 Bus 96 Input I / F 98 Output I / F

Claims

1. A method for operating a combustion device that combusts fuel, comprising: Regarding ash produced by the combustion of the fuel, SiO in the ash ２ , CaO, MgO, Na ２ O and K ２ The content of O is R ＳｉＯ２ [wt%], R ＣａＯ [wt%] 、 R ＭｇＯ [wt%], R Ｎａ２Ｏ [wt%] and R Ｋ２Ｏ [wt %], a first coefficient m is defined as a coefficient greater than 0 and less than 5, and a second coefficient n is defined as a coefficient greater than 0 and less than 3, and (R ＳｉＯ２ +R ＣａＯ +mR ＭｇＯ +R Ｎａ２Ｏ +nR Ｋ２Ｏ ) to R ｓｕｍ and R ｓｕｍ R against ＳｉＯ２ R is the ratio of ＳｉＯ２ / R ｓｕｍ is the first coordinate axis, R ｓｕｍ (R ＣａＯ +mR ＭｇＯ ) is the ratio of (R ＣａＯ +mR ＭｇＯ ) / R ｓｕｍ is the second coordinate axis, R ｓｕｍ (R Ｎａ２Ｏ +nR Ｋ２Ｏ ) is the ratio of (R Ｎａ２Ｏ +nR Ｋ２Ｏ ) / R ｓｕｍ If we define a triangular coordinate system with the third coordinate axis as A method for operating a combustion device, comprising the steps of: detecting the components of the ash by analyzing the fuel or the ash; and operating the combustion device so that the composition of the ash is located within a first range surrounded by the first coordinate axis, the second coordinate axis, and a first boundary line connecting a first position on the first coordinate axis that is a value greater than 0.5 and less than 1, and a second position on the second coordinate axis that is a value greater than 0.3 and less than 0.8, in the triangular coordinate system.

2. 2. The method for operating a combustion device according to claim 1, wherein the value of the first position on the first coordinate axis is greater than the value of the second position on the second coordinate axis.

3. the first position is a value greater than 0.7 and less than 0.9 on the first coordinate axis, 3. The method for operating a combustion device according to claim 2, wherein the second position is a value on the second coordinate axis that is greater than 0.3 and less than 0.

7.

4. Al in the ash ２ O ３ The content of R Ａｌ２Ｏ３ If we define it as: In the step, R ＳｉＯ２ R against Ａｌ２Ｏ３ R is the ratio of Ａｌ２Ｏ３ / R ＳｉＯ２ The method for operating a combustion device according to claim 1 , further comprising changing the first boundary line in response to a change in the first boundary line.

5. In the step, R Ａｌ２Ｏ３ / R ＳｉＯ２ 5. The method for operating a combustion device according to claim 4, wherein the first boundary line is changed so that the value of the first position increases as the value of the first boundary line decreases.

6. In the step, when the composition of the ash falls outside the first range of the triangular coordinates, SiO ２ and AlO ２ 2. The method for operating a combustion device according to claim 1, further comprising increasing the amount of additives added to the combustion device, the additives including at least one of:

7. the combustion device is a gasification furnace of a coal gasification combined cycle power generation system, 7. The method for operating a combustion apparatus according to claim 6, wherein the step of increasing the amount of the additive fed to the reductor section of the gasification furnace when the ash composition falls outside the first range of the triangular coordinates.

8. the combustion device is a gasification furnace of a coal gasification combined cycle power generation system, Al in the additive ２ O ３ The content [wt %] of SiO in the additive ２ The method for operating a combustion apparatus according to claim 6, wherein a value obtained by dividing the above by the content [wt %] of the above is 0 or more and 0.25 or less.

9. the combustion device is a gasification furnace of a coal gasification combined cycle power generation system, 2. The method for operating a combustion device according to claim 1, wherein in the step, the combustion device is operated so that the ash composition is located within a second range in the triangular coordinate system surrounded by the second coordinate axis, the first boundary line, and a second boundary line extending from a third position on the second coordinate axis that is greater than 0 and smaller than the second position so as to intersect with the first boundary line.

10. 10. The method for operating a combustion device according to claim 9, wherein, in the step, when the ash composition deviates from the second range of the triangular coordinates toward the first coordinate axis, the amount of additive containing an alkaline earth metal fed to the gasification furnace is increased.

11. the fuel includes a first fuel and a second fuel having a composition different from that of the first fuel, the combustion device is configured to co-combust the first fuel and the second fuel; 2. The method for operating a combustion device according to claim 1, wherein, in the step, the first fuel and the second fuel are co-combusted at a co-combustion ratio determined so that a composition of ash produced by co-combusting the first fuel and the second fuel is located within the first range of the triangular coordinates.

12. A method for selecting a fuel for a combustion device, comprising: Regarding ash produced by the combustion of the fuel, SiO in the ash ２ , CaO, MgO, Na ２ O and K ２ The content of O is R ＳｉＯ２ [wt%], R ＣａＯ [wt%] 、 R ＭｇＯ [wt%], R Ｎａ２Ｏ [wt%] and R Ｋ２Ｏ [wt %], a first coefficient m is defined as a coefficient greater than 0 and less than 5, and a second coefficient n is defined as a coefficient greater than 0 and less than 3, and (R ＳｉＯ２ +R ＣａＯ +mR ＭｇＯ +R Ｎａ２Ｏ +nR Ｋ２Ｏ ) to R ｓｕｍ and R ｓｕｍ R against ＳｉＯ２ R is the ratio of ＳｉＯ２ / R ｓｕｍ is the first coordinate axis, R ｓｕｍ (R ＣａＯ +mR ＭｇＯ ) is the ratio of (R ＣａＯ +mR ＭｇＯ ) / R ｓｕｍ is the second coordinate axis, R ｓｕｍ (R Ｎａ２Ｏ +nR Ｋ２Ｏ ) is the ratio of (R Ｎａ２Ｏ +nR Ｋ２Ｏ ) / R ｓｕｍ If we define a triangular coordinate system with the third coordinate axis as A fuel selection method comprising a step of: detecting the ash components by analyzing the fuel or the ash for a plurality of candidate fuels; and selecting as the fuel a candidate whose ash composition is located within a first range in the triangular coordinate system surrounded by the first coordinate axis, the second coordinate axis, and a first boundary line connecting a first position on the first coordinate axis that is greater than 0.5 and less than 1, and a second position on the second coordinate axis that is greater than 0.3 and less than 0.

8.

13. An operation control system for a combustion device that burns fuel, Regarding ash produced by the combustion of the fuel, SiO in the ash ２ , CaO, MgO, Na ２ O and K ２ The content of O is R ＳｉＯ２ [wt%], R ＣａＯ [wt%] 、 R ＭｇＯ [wt%], R Ｎａ２Ｏ [wt%] and R Ｋ２Ｏ [wt %], a first coefficient m is defined as a coefficient greater than 0 and less than 5, and a second coefficient n is defined as a coefficient greater than 0 and less than 3, and (R ＳｉＯ２ +R ＣａＯ +mR ＭｇＯ +R Ｎａ２Ｏ +nR Ｋ２Ｏ ) to R ｓｕｍ and R ｓｕｍ R against ＳｉＯ２ R is the ratio of ＳｉＯ２ / R ｓｕｍ is the first coordinate axis, R ｓｕｍ (R ＣａＯ +mR ＭｇＯ ) is the ratio of (R ＣａＯ +mR ＭｇＯ ) / R ｓｕｍ is the second coordinate axis, R ｓｕｍ (R Ｎａ２Ｏ +nR Ｋ２Ｏ ) is the ratio of (R Ｎａ２Ｏ +nR Ｋ２Ｏ ) / R ｓｕｍ If we define a triangular coordinate system with the third coordinate axis as a detection unit that detects components of the ash by analyzing the fuel or the ash; an operation control unit that operates the combustion device so that the composition of the ash is located within a first range surrounded by the first coordinate axis, the second coordinate axis, and a first boundary line that connects a first position on the first coordinate axis that is a value greater than 0.5 and less than 1, and a second position on the second coordinate axis that is a value greater than 0.3 and less than 0.8, in the triangular coordinate system; An operation control system for a combustion device comprising:

14. SiO ２ and AlO ２ An additive supply unit configured to supply an additive including at least one of the following to the combustion device, 14. The combustion device operation control system according to claim 13, wherein the operation control unit controls the additive supply unit to increase the amount of the additive fed to the combustion device when the ash composition falls outside the first range of the triangular coordinates.

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