Boiler device, its operating method, and power generation system equipped with the boiler device

Abstract

To achieve safer combustion control of a mixed fuel by suppressing unwanted ignition of an inorganic fuel when mixing and igniting organic and inorganic fuels.SOLUTION: A power generation system 100, 200 according to the present disclosure includes a boiler device having: a combustion chamber 21; and a fuel supply part having a fuel holding part 11 for holding an organic fuel F1 and a fuel holding part 12 for holding an inorganic fuel F2. The fuel supply part adjusts a delivery state of the organic fuel F1 from the fuel holding part 11 and a delivery state of the inorganic fuel F2 from the fuel holding part 12 such that the mixed fuel F of the organic fuel F1 and the inorganic fuel F2 is supplied to the combustion chamber 21 when at least one of the following conditions is satisfied; (1) before a predefined period of time from the mixing; (2) before the mixed fuel reaching a predefined temperature; and (3) before the steam generated from the mixed fuel reaching the predefined quantity.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a boiler apparatus, an operating method thereof, and a power generation system including the boiler apparatus. [Background technology]

[0002] Recently, in response to the problem of global warming, there has been an urgent need to reduce emissions of greenhouse gases such as carbon dioxide emitted from thermal power plants. For this reason, for example, Patent Document 1 describes an example of a boiler system that burns biomass fuel in addition to coal, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7371795 Summary of the Invention [Problem to be solved by the invention]

[0004] As shown in FIG. 2 of Patent Document 1, the conventional boiler system includes a bunker 250 connected to a furnace 112 via a mill 252, and a fuel supply unit 110 connected to the bunker 250. The fuel supply unit 110 has a first fuel storage section 210 in which biomass fuel is stored, a second fuel storage section 212 in which coal is stored, and an additive storage section 214 in which an additive such as silica is stored, all of which are connected to the bunker 250 via piping. With this configuration, the biomass fuel, coal, and additives are mixed in the bunker before being supplied to the furnace 112, and the mixture is pulverized in the mill 252 and then sent to the furnace 112 for combustion.

[0005] As described above, in the conventional boiler system, different fuels are mixed in the bunker, then passed through a mill before being introduced into the furnace, which means that it takes a considerable amount of time for the fuel mixture to reach the furnace. Assume that the different fuels used in the conventional boiler system are an organic fuel (such as coal, wood chips, wood pellets, or plant-derived solid fuels such as palm kernel shells) that may contain a relatively large amount of moisture, and an inorganic fuel that primarily contains metals. In this case, in the area where the two fuels come into contact or are mixed in the bunker (the mixing layer), a chemical reaction between the moisture contained in the organic fuel (including when it is simply "attached" to the organic fuel; the same applies hereinafter in this specification) and the inorganic fuel may occur, generating heat.

[0006] This type of heat generation is different from the expected heat generation due to the fermentation of organic fuels. Because it is heat generation due to the oxidation of inorganic fuels, the exothermic oxidation reaction continues as long as moisture remains in the organic fuel. This results in a rise in temperature inside the bunker, and in some cases, it can even lead to fire. Furthermore, if the inorganic fuel contains easily oxidized metals, combustion continues by removing oxygen covalently bonded to the carbon dioxide and carbon monoxide molecules produced by the combustion of the organic fuel. This means that even if the supply of oxygen from outside (e.g., oxygen gas in the air) is cut off, it can be difficult to extinguish the fire inside the bunker.

[0007] Therefore, the present disclosure has been made in consideration of the above circumstances, and aims to provide a boiler apparatus that can suppress unnecessary ignition of inorganic fuel when co-combusting organic fuel and inorganic fuel, thereby achieving safer combustion control of the mixed fuel, a method for operating the same, and a power generation system equipped with the boiler apparatus. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention employs the following configuration.

[0009] [1] An example of a boiler apparatus according to the present disclosure includes a combustion chamber, a fuel supply unit having a first holding unit for holding an organic fuel, and a second holding unit for holding an inorganic fuel. The fuel supply unit adjusts the delivery state of the organic fuel from the first holding unit and the delivery state of the inorganic fuel from the second holding unit so that at least a portion (desirably, ideally all) of the mixed fuel, which is a mixture of the organic fuel and the inorganic fuel, is supplied to the combustion chamber when at least one of the following conditions is satisfied: (1) before a predetermined time has elapsed since mixing, (2) before the mixed fuel reaches a predetermined temperature, and (3) before the amount of steam generated from the mixed fuel reaches a predetermined amount.

[0010] In this configuration, when combusting organic fuel and inorganic fuel, at least a portion of the mixed fuel (mixed layer before co-combustion) is prevented from remaining in contact or mixed state for a long period of time before reliable co-combustion of the two occurs, thereby effectively preventing unintended ignition and combustion due to a reaction between the moisture contained in the organic fuel and the inorganic fuel.

[0011] [2] More specifically, in the above configuration, at least one of the predetermined time, the predetermined temperature, and the predetermined amount of steam may be suitably determined based on at least one parameter selected from the amounts of organic fuel and inorganic fuel, the reactivity between the organic fuel and inorganic fuel, the mixing ratio of the organic fuel and inorganic fuel, the supply rate of the mixed fuel to the combustion chamber, and the properties of the organic fuel and inorganic fuel (type of material, composition, chemical form, etc.). More strictly, the "mixing ratio" here is preferably defined as the "mixing ratio" in a "mixing layer" of the organic fuel and the inorganic fuel that may occur before the organic fuel and the inorganic fuel are substantially mixed and burned.

[0012] Here, the "predetermined time" in the present disclosure can be said to correspond to the "allowable time" from the mixing of the organic fuel and the inorganic fuel until the chemical reaction between them progresses to an undesirable extent. Similarly, the "predetermined temperature" can be said to correspond to the "allowable temperature," and the "predetermined amount" can be said to correspond to the "allowable amount." Therefore, by determining at least one of the predetermined time, the predetermined temperature, and the predetermined amount based on parameters that can affect the progress and reaction rate of the chemical reaction between the two, unintended ignition and combustion due to the reaction of the mixed fuel can be more reliably prevented.

[0013] [3] In the above configuration, the fuel supply unit may include a first pipe connecting one of the first and second holding units to the combustion chamber, and a second pipe connecting the other of the first and second holding units to the first pipe. By providing and connecting the first and second pipes in this manner, the time during which the organic fuel and the inorganic fuel remain in contact or mixed can be set as desired by changing the distance from the junction of the two pipes to the combustion chamber. Furthermore, for example, it is easy to position the junction of the first and second pipes as close as possible to the combustion chamber, making it easy to mix the organic fuel and the inorganic fuel approximately immediately before the combustion chamber.

[0014] [4] Furthermore, in this case, the distance between the junction of the first and second pipes and the combustion chamber and / or the supply rate of the mixed fuel to the combustion chamber may be determined based on at least one of the above-mentioned "predetermined time," "predetermined temperature," and "predetermined amount of steam." In other words, if operating conditions such as the supply rates of the organic fuel and inorganic fuel are controlled, this "distance" can be one of the main parameters that influence at least one of the "predetermined time," "predetermined temperature," and "predetermined amount of steam." This has the advantage of more reliably supplying the mixed fuel of organic fuel and inorganic fuel to the combustion chamber within the "predetermined time," while the temperature is below the "predetermined temperature," or before the "predetermined amount of steam" is generated.

[0015] [5] Here, the term "organic fuel" refers to a fuel containing carbon or hydrocarbons, and the term "inorganic fuel" refers to a fuel that does not contain carbon or hydrocarbons and that contains metals or metal hydrides.

[0016] [6] In this case, the second holding section that holds the inorganic fuel may be configured to have a processing section that processes the metal and / or metal hydride raw materials into inorganic fuel while holding them under an atmosphere containing an inert gas.

[0017] [7] More specifically, the inorganic fuel may preferably contain at least one of metals such as lithium, boron, magnesium, aluminum, and calcium, and metal hydrides such as lithium hydride, boron hydride, magnesium hydride, aluminum hydride, and calcium hydride.

[0018] [8] An example of a method for operating a boiler apparatus according to the present disclosure is a method that is effectively implemented using the boiler apparatus according to the present disclosure. That is, in this method, the delivery state of the organic fuel from the first holding unit and the delivery state of the inorganic fuel from the second holding unit are adjusted so that at least a portion of the mixed fuel, which is a mixture of organic fuel and inorganic fuel, is supplied to the combustion chamber when at least one of the following conditions is satisfied: (1) before a predetermined time has elapsed since mixing, (2) before the mixed fuel reaches a predetermined temperature, and (3) before the amount of steam generated from the mixed fuel reaches a predetermined amount.

[0019] [9] In this case, at least one of the predetermined time, the predetermined temperature, and the predetermined amount of steam may be determined based on at least one parameter of the amounts of organic fuel and inorganic fuel, the reactivity between the organic fuel and inorganic fuel, the mixing ratio of the organic fuel and inorganic fuel, the supply rate of the mixed fuel to the combustion chamber, and the properties of the organic fuel and inorganic fuel (type of material, composition, chemical form, etc.).

[0020]

[10] An example of a power generation system according to the present disclosure is a system that is effectively configured using a boiler device according to the present disclosure, and includes a boiler device according to the present disclosure and a generator that generates electricity using steam generated by the boiler device. [Effects of the Invention]

[0021] According to the present disclosure, when organic fuel and inorganic fuel are mixed and combusted, unnecessary ignition of the inorganic fuel can be suppressed, thereby realizing safer combustion control of the mixed fuel. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic configuration diagram showing an example of the configuration of a power generation system including a boiler device according to a first embodiment of the present disclosure. [Figure 2] FIG. 10 is a schematic configuration diagram showing an example of the configuration of a power generation system including a boiler device according to a second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present embodiment will be described below with reference to the accompanying drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

[0024] (First embodiment) 1 is a schematic diagram showing an example of the configuration of a thermal power generation system as an example of a power generation system including a boiler apparatus according to a first embodiment of the present disclosure. As shown in the figure, the power generation system 100 includes a generator 1, a boiler 2 that drives the generator 1, and a hopper 3 that supplies a mixed fuel F of an organic fuel F1 and an inorganic fuel F2 to the boiler 2.

[0025] The boiler 2 includes a combustion chamber 21, a superheater 22 that generates steam V using the heat of combustion of a mixed fuel F, and a steam turbine 23 that is driven by the steam generated in the superheater 22 and has a rotating shaft connected to the generator 1. Of these, the combustion chamber 21 includes a main combustion chamber 21A and a flue 21B that defines a flow path for high-temperature exhaust gas EG (shown by a broken line in the figure) generated in the main combustion chamber 21A. The combustion chamber 21 is provided upstream of the flow path of the exhaust gas EG, and the flue 21B that communicates with it has a flow path structure that allows the exhaust gas EG to make multiple turns. The superheater 22 is also located downstream of the flow path of the exhaust gas EG, and the exhaust gas EG' that has passed through the superheater 22 is discharged from the flue 21B through an exhaust pipe PU.

[0026] Here, the organic fuel F1 is preferably a fuel containing carbon or hydrocarbon. Specific examples of the organic fuel F1 include coal, coal gas, fossil fuels that are liquid at room temperature and pressure, petroleum-based fuels (hydrocarbon-based fuels that are liquid at room temperature and pressure) such as heavy oil and light oil, biomass solid fuels such as wood chips, wood pellets, and palm kernel shells, liquid fuels such as bioethanol and biodiesel, and gaseous fuels such as biogas. The organic fuel F1 can also be considered to generate carbon oxide gases (carbon monoxide gas, carbon dioxide gas, etc.) that serve as combustion-supporting gases for the inorganic fuel F2 described below.

[0027] On the other hand, it is preferable that the inorganic fuel F2 does not contain carbon or hydrocarbons and contains a metal or metal hydride. Specifically, the inorganic fuel F2 may be at least one selected from the group consisting of lithium, boron, magnesium, aluminum, and calcium, and at least partially hydrogenated versions of these elements, i.e., lithium hydride, boron hydride, magnesium hydride, aluminum hydride, and calcium hydride. These inorganic fuels F2 may be used alone or in combination of two or more, and of course, a mixture of a metal and a metal hydride may also be used. It is sufficient that these hydrides have a hydrogenated layer formed at least on the surface of the metal. Inorganic fuel F2 can also be considered as not generating carbon oxide gases (carbon monoxide gas, carbon dioxide gas, etc.) during combustion.

[0028] Furthermore, before being introduced into the hopper 3, the organic fuel F1 and the inorganic fuel F2 are separately stored in fuel storage units 11, 12 (corresponding to examples of a "first storage unit" and a "second storage unit") such as storage tanks. In particular, as the inorganic fuel F2, it is preferable that an ingot (lump) metal raw material (which may have a hydrogenated surface) is successively processed and introduced into the hopper 3. Note that the term "processing" in the present disclosure is a concept that can encompass all metal processing such as pulverization, micronization, pulverization, crushing, crushing, grinding, etc., and the processing equipment is not particularly limited, and devices, tools, etc. that are used in ordinary metal processing can be used.

[0029] In the power generation system 100 configured as described above, the organic fuel F1 and the inorganic fuel F2 are respectively fed from the fuel storage units 11 and 12 into the hopper 3, immediately mixed, and then introduced into the main combustion chamber 21A as the mixed fuel F. As a result, the mixed fuel F is supplied to the combustion chamber 21 within a predetermined time. In this manner, the hopper 3 and the fuel storage units 11 and 12 provided upstream thereof correspond to an example of a "fuel supply unit" that adjusts the delivery state of the organic fuel F1 and the delivery state of the inorganic fuel F2. Furthermore, the boiler 2 equipped with the combustion chamber 21, the fuel storage units 11 and 12, and the hopper 3 constitute an example of a "boiler apparatus" according to the present disclosure.

[0030] Next, the mixed fuel F that has flowed into the main combustion chamber 21A passes through the drying stoker 5, combustion stoker 6, and post-combustion stoker 7 in that order within the main combustion chamber 21A. At this time, primary combustion air (not shown) is supplied into the main combustion chamber 21A from below the drying stoker 5, combustion stoker 6, and post-combustion stoker 7. This primary combustion air dries the organic fuel F1 in the mixed fuel F on the drying stoker 5 and heats it to near its ignition point. The dried organic fuel F1 is ignited on the combustion stoker 6 and then combusts on the combustion stoker 6 and post-combustion stoker 7. Furthermore, a portion of the ignited and combusted organic fuel F1 decomposes to produce flammable gas, which moves to the upper part of the main combustion chamber 21A. At this time, although not shown in the figure, secondary combustion air is supplied from, for example, the ceiling part of the main combustion chamber 21A toward the inside of the main combustion chamber 21A, so that the combustible gas derived from the organic fuel F1 is mixed with the secondary combustion air and completely combusted.

[0031] The high-temperature flue gas EG generated by the combustion of the organic fuel F1 flows downstream while bending the flue 21B. During this process, combustion ash 41 and other components contained in the flue gas EG are efficiently collected in the combustion ash collection section 8 via the chute 4. The flue gas EG' from which the combustion ash has been removed is discharged from the flue 21B through the exhaust pipe PU, and after undergoing appropriate flue gas treatment as necessary, is released into the atmosphere through a chimney or other device (not shown). Furthermore, heat exchange with the flue gas EG' generates steam V (solid arrow) in the superheater 22, which drives the steam turbine 23 and generates electricity using the generator 1. The steam V is then cooled by passing through the condenser FU to become liquid water W, which is then returned to the superheater 22 by the feedwater pump P. The cycle of the steam V then turning back into steam and being supplied to the steam turbine 23 is continuously repeated.

[0032] On the other hand, when the inorganic fuel F2 in the mixed fuel F does not contain carbon or hydrocarbons as described above, the reactions represented by the following formulas (1) to (8) proceed, and no carbon oxide gases such as carbon dioxide or carbon monoxide are generated during combustion. These reactions involving the inorganic fuel F2 are exothermic reactions that release high-temperature heat, and even if the amount of organic fuel F1 used is at least equivalent to the amount of heat released, it is possible to maintain the same amount of power generation as before the amount of organic fuel F1 used was reduced.

[0033] 4Li + O2 → 2Li2O (1) 4B+ 3O2 → 2B2O3(2) 2Mg + O2 → 2MgO (3) 4Al + 3O2 → 2Al2O3(4) 2Ca + O2 → 2CaO (5) 2LiH + O → LiO + HO (6) 2BH3 + 3O2 → B2O3 + 3H2O (7) MgH2+ O2 → MgO + H2O (8) 2AlH3+ 3O2 → Al2O3+ 3H2O (9) CaH2+ O2 → CaO + H2O (10)

[0034] Furthermore, because organic fuel F1 is derived from plants that grow by absorbing greenhouse gases such as carbon dioxide from the atmosphere, it contributes to the natural cycle of greenhouse gases. In this respect, thermal power generation using organic fuel F1 is considered to be a carbon-neutral power generation method.

[0035] (Second embodiment) 2 is a schematic diagram showing an example of the configuration of a thermal power generation system as an example of a power generation system including a boiler apparatus according to a second embodiment of the present disclosure. As shown in the figure, the power generation system 200 includes a generator 1, a boiler 2 that drives the generator 1, a fuel storage unit 11 (an example of a "first storage unit") such as a silo that stores an organic fuel F1 to be supplied to the boiler 2, and a fuel storage unit 12 (an example of a "first storage unit") that stores an ingot that is a raw material G2 for the inorganic fuel and has a processing machine 120 (an example of a "processing machine") such as a milling cutter that produces the inorganic fuel F2 from the raw material G2.

[0036] The boiler 2 includes a combustion chamber 21, a superheater 22 that generates steam V using the heat of combustion of the mixed fuel F, and a steam turbine 23 that is driven by the steam generated in the superheater 22 and has a rotating shaft connected to the generator 1. A fuel storage unit 11 is connected to the combustion chamber 21 via a shutter S1 and a pipe P1 (an example of a "first pipe"). A fuel storage unit 12 is connected to a portion of the pipe P1 near the combustion chamber 21 via a shutter S2 and a pipe P2 (an example of a "second pipe"). A cyclone 31 is further connected downstream of the combustion chamber 21 via a pipe P3. A bottom of the cyclone 31 is connected to a lower part of the combustion chamber 21 via a pipe P4, and a superheater 32 is provided midway along the pipe P4. A dust collector 34 is connected to an upper part of the cyclone 31 via a pipe P5. The superheater 22 and an air preheater 33 are provided midway along the pipe P5. The air preheater 33 also has a straight pipe section 33a and an air intake section 33b wound around the circumferential wall of the straight pipe section 33a. The straight pipe section 33a also serves as part of the piping P5, and the air intake section 33b functions as a suction section for air K. The air preheater 33 is further connected via a piping P6 to an air blowing section 21b attached to the bottom of the combustion chamber 21, and a blower 34 is provided midway along the piping P6.

[0037] In the power generation system 200 configured as described above, for example, organic fuel F1 transported as needed is introduced into the fuel storage unit 11 through a supply port 11a having an on-off valve and temporarily stored therein. At this time, an inert gas IG flows into the fuel storage unit 11 through a supply port 11b also having an on-off valve. This replaces (purges) part of the air in the fuel storage unit 11 with the inert gas IG, preventing heat generation due to fermentation caused by contact between the organic fuel F1 (especially biomass fuel, etc.) and oxygen in the air. Note that, from the viewpoint of promoting combustion of the mixed fuel F in the combustion chamber 21, it is desirable to avoid replacing the air in the fuel storage unit 11 with the inert gas IG. Then, the opening degree and opening time of the shutter S1 are controlled according to the required amount, and the stored organic fuel F1 is sent to the combustion chamber 21 through the pipe P1.

[0038] Meanwhile, the fuel storage unit 12 is located as close as possible to the combustion chamber 21, and contains the inorganic fuel F2 raw material G2 and a processing machine 120 for the raw material G2. The raw material G2 is then crushed from its surface by metal processing such as rotary cutting in the fuel storage unit 12 according to the required amount, producing, for example, pulverized inorganic fuel F2. At this time, an inert gas IG flows into the fuel storage unit 12 through a supply port 12b having an open / close valve. This purges the air in the fuel storage unit 12, allowing it to be substantially filled with the inert gas IG. This effectively prevents ignition of cutting dust and the like due to static electricity, friction, and the like when the raw material G2 is being cut. The inorganic fuel F2 thus obtained is temporarily stored in the bottom of the fuel storage unit 12, and then, according to the required amount, the opening degree and opening time of the shutter S2 are controlled, and the inorganic fuel F2 is delivered to the combustion chamber 21 through the pipe P2.

[0039] The organic fuel F1 and inorganic fuel F2 respectively delivered to the combustion chamber 21 side of the boiler 2 in the manner described above are joined and mixed at the confluence J of the pipes P1 and P2, and then immediately introduced into the combustion chamber 21 as mixed fuel F. As a result, the mixed fuel F is supplied to the combustion chamber 21 within a predetermined time. In this manner, the fuel storage units 11 and 12 and the pipes P1 and P2 correspond to an example of a "fuel supply unit" that adjusts the delivery state of the organic fuel F1 and the delivery state of the inorganic fuel F2. Furthermore, the boiler 2 equipped with the combustion chamber 21, the fuel storage units 11 and 12, and the pipes P1 and P2 constitute an example of a "boiler apparatus" according to the present disclosure.

[0040] Here, primary combustion air (air preheated by exhaust heat, as described below) is supplied into the combustion chamber 21 from the air outlet 21b below, and is preheated. The mixed fuel F that flows into the combustion chamber 21 is heated and dried (especially the contained organic fuel F1) by the internal preheating, heated to near the ignition point, and then further heated until it ignites and burns completely. In addition, a portion of the ignited and burned organic fuel F1 decomposes to produce flammable gas, which moves to the upper part of the combustion chamber 21. At this time, although not shown in the figure, secondary combustion air is supplied from, for example, the ceiling portion of the combustion chamber 21 toward the interior of the combustion chamber 21, and the flammable gas derived from the organic fuel F1 is mixed with the secondary combustion air and completely combusted.

[0041] The high-temperature exhaust gas EG generated by the combustion of the organic fuel F1 flows into the cyclone 31 through the pipe P3 and flows through the cyclone 31. During this time, the combustion ash contained in the exhaust gas EG is separated from the exhaust gas EG by centrifugal separation, with most of it remaining at the bottom of the cyclone 31 and being recovered from the cyclone 31 by an appropriate method and timing (for example, periodically using a mobile container). The exhaust gas EG from which most of the combustion ash has been removed is divided into two and moves to the pipe P4 side connected to the bottom of the cyclone 31 and the pipe P5 side connected to the top of the pipe P4.

[0042] The exhaust gas EG flowing through the pipe P4 passes through the superheater 32 and is returned to the combustion chamber 21, contributing to preheating the combustion chamber 21. At this time, water W is supplied into the superheater 32, and water W exchanges heat with the exhaust gas EG to generate steam V, which is used as an appropriate heat source. Meanwhile, the exhaust gas EG flowing through the pipe P5 passes through the superheater 22 and the air preheater 33 in sequence, and is sent to the dust collector 34. At this time, water W is supplied into the superheater 22, and water W exchanges heat with the exhaust gas EG to generate steam V, which drives the steam turbine 23 and generates electricity using the generator 1. Furthermore, the exhaust gas EG that has passed through the superheater 22 flows into the straight pipe section 33a of the air preheater 33 while retaining a certain amount of heat (exhaust heat), where it exchanges heat with air K drawn into the air intake section 33b, and is then sent to the dust collector 34. In the dust collector 34, combustion ash 41 remaining in the exhaust gas EG is collected and efficiently recovered in the combustion ash recovery section 8. In addition, the air K heated in the air preheater 33 becomes temporary combustion air, and is circulated through the pipe P6 by the blower 34 and sent to the air blowing section 21b of the combustion chamber 21.

[0043] On the other hand, when the inorganic fuel F2 in the mixed fuel F does not contain carbon or hydrocarbons, as in the first embodiment, the reactions shown in the formulas (1) to (8) proceed, and no carbon oxide gases such as carbon dioxide or carbon monoxide are generated during combustion. These reactions caused by the inorganic fuel F2 are exothermic reactions that release high-temperature heat, and even if the amount of organic fuel F1 used is at least equivalent to the amount of heat released, it is possible to maintain the same amount of power generation as before the amount of organic fuel F1 used is reduced.

[0044] The boiler apparatus having the boiler 2 configured as described above, and the power generation systems 100, 200 including the boiler apparatus, can mix organic fuel F1 and inorganic fuel F2 and burn the mixed fuel F to generate power. In addition, since the mixed fuel F is quickly introduced into the combustion chamber 21 at this time, at least a portion of the mixed fuel F (the mixed layer before co-combustion) is prevented from remaining in contact or mixed state for a long period of time before reliable co-combustion of the two fuels occurs in the combustion chamber 21. This effectively prevents unintended ignition and combustion due to a reaction between the moisture contained in the organic fuel and the inorganic fuel, thereby enabling safer combustion control of the mixed fuel F.

[0045] Here, in both power generation systems 100 and 200, at least one of the conditions for at least a portion of the mixed fuel F may be determined based on at least one parameter selected from the amounts of organic fuel F1 and inorganic fuel F2, the reactivity (reaction rate) between organic fuel F1 and inorganic fuel F2 (or the moisture contained therein), the mixing ratio of organic fuel F1 and inorganic fuel F2, the supply rate of mixed fuel F to combustion chamber 21, and the properties of organic fuel F1 and inorganic fuel F2 (such as the type of material, composition, or chemical form). The conditions include: (1) the predetermined time (i.e., the maximum allowable time) from mixing organic fuel F1 and inorganic fuel F2 to supplying the mixed fuel F to combustion chamber 21; (2) the predetermined temperature (i.e., the maximum allowable temperature) reached by the reaction occurring in the mixed fuel F before it is transported to combustion chamber 21; and (3) the predetermined amount of steam (i.e., the maximum allowable amount). In this way, the predetermined time, predetermined temperature, or predetermined amount of steam is determined based on parameters that can affect the progress and reaction rate of the chemical reaction between the organic fuel F1 and the inorganic fuel F2, thereby more reliably preventing unintended ignition and combustion caused by the reaction of the mixed fuel F.

[0046] As described above, the power generation system 200 is provided with a pipe P1 connecting the fuel storage unit 11 and the combustion chamber 21, and a pipe P2 connecting the fuel storage unit 12 and the pipe P1, and the organic fuel F1 and the inorganic fuel F2 are mixed at the junction J of the two pipes P1 and P2. This makes it easy to set the desired residence time for the organic fuel F1 and the inorganic fuel F2 in a contact or mixed state by changing the distance from the junction J to the combustion chamber 21. Furthermore, in the power generation system 200, the junction J of the pipes P1 and P2 is located immediately before the combustion chamber 21, which more reliably prevents unexpected ignition or heat generation of the mixed fuel F.

[0047] More specifically, it is preferable to determine the distance between the confluence J of the pipes P1 and P2 and the combustion chamber 21 and / or the supply rate of the mixed fuel F to the combustion chamber 21 based on at least one of a "predetermined time," a "predetermined temperature," and a "predetermined amount of steam." That is, if operating conditions such as the supply rates of the organic fuel F1 and the inorganic fuel F2 are controlled (understood), the correlation between the "distance" and / or "supply rate" and the "predetermined time," "predetermined temperature," or "predetermined amount of steam" can be obtained, thereby advantageously enabling the "distance" corresponding to the "predetermined time," "predetermined temperature," or "predetermined amount of steam" to be accurately set. Note that the distance between the confluence J of the pipes P1 and P2 and the combustion chamber 21 can actually be set on the order of, for example, several tens of centimeters to several meters. Alternatively, multiple confluences J of the pipes P1 and P2 may be provided and controlled or managed so as to be switched appropriately, or the point of the confluence J of the pipes P1 and P2 may be variable so as to adjust its position.

[0048] The present embodiment has been described above with reference to specific examples. However, this is for the purpose of facilitating understanding of the present disclosure and is not intended to limit the present disclosure. In other words, the present disclosure is not limited to these specific examples. Design modifications to these specific examples made by a person skilled in the art are also encompassed within the technical scope of the present disclosure as long as they comprise the features of the present disclosure. Furthermore, unless otherwise specified, the elements, arrangements, materials, conditions, shapes, dimensions, sizes, scales, etc. of the above-described specific examples are not limited to those exemplified and can be modified as appropriate. Furthermore, the elements of the above-described specific examples can be combined in various ways as appropriate, as long as no technical contradictions arise.

[0049] For example, instead of connecting the pipe P1 to the pipe P2, the pipe P1 may be connected to the pipe P2, or a separate pipe may be provided at the junction J of the two pipes and connected to the combustion chamber 21. Treatment of the exhaust gas EG' includes, for example, denitrification to render nitrogen oxides (NOx) harmless. However, in recent years, measures such as controlling the combustion temperature and increasing the oxygen concentration in the air as a combustion-supporting gas have been implemented to prevent the generation of nitrogen oxides (NOx) exceeding environmental emission standards. In such cases, a denitrification device is not required. Furthermore, a combustion burner for burning liquid fuel or gaseous fuel may be provided in the combustion chamber 21. Furthermore, the hopper 3 shown in FIG. 1 may be replaced by the pipes P1 and P2 shown in FIG. 2. Furthermore, multiple fuel storage units 11 and 12 may be provided, and multiple processing machines 120 may be installed in the fuel storage unit 12. Furthermore, the boiler 2 may be provided with a pressure regulation system for maintaining the pressure in the combustion chamber 21 at a predetermined pressure. Furthermore, the power generation systems 100 and 200 are not only capable of combusting the organic fuel F1 and the inorganic fuel F2 together, but are also capable of combusting each fuel independently (single combustion).

[0050] As shown in FIG. 1, tertiary combustion air may also be supplied to the flue 21B near the main combustion chamber 21A to form a re-burning section N for promoting combustion. This ensures the combustion of unburned carbon monoxide, hydrogen generated by decomposition of hydrides, ammonia generated by decomposition of nitrides, and other contaminants, thereby ensuring efficient use of thermal energy and the suppression of harmful gases (carbon monoxide, ammonia, etc.). While primary combustion air, secondary combustion air, and tertiary combustion air have been presented as combustion gases for combustion, oxygen-enriched air, oxygen itself, or a mixture of carbon dioxide gas and air may also be used, and these may also be used as combustion-supporting gases. Furthermore, the illustrated boiler configuration is an example assuming the use of solid or liquid fuel as the organic fuel F1. However, as previously mentioned, gaseous fuels can also be used as the organic fuel F1. In either case, the boiler configuration, including the fuel storage section, can be appropriately selected depending on the type of organic fuel F1.

[0051] Incidentally, the combustion ash derived from inorganic fuel F2 consists of highly pure carbon powder and oxides of the above fuel metals (which may contain hydroxides in some cases). Therefore, if the carbon powder is recovered, it is useful as a raw material for carbon materials, and the metals can be regenerated using the oxides as starting materials. In other words, a resource-circulating power generation method in which these metal resources are circulated can be realized.

[0052] To give a specific example, if the inorganic fuel F1 is magnesium or calcium, for example, the magnesium oxide or calcium oxide contained in the combustion ash 41 can be used as a starting material to refine magnesium again, thereby realizing resource recycling. In this case, the oxide may be directly reduced by a known method to produce the metal, or an intermediate (e.g., a chloride) may be produced first and then the intermediate may be reduced to produce the metal. In particular, in the latter case, a chlorination step to produce the chloride and a molten salt electrolysis step to obtain the metal using the chloride produced in the chlorination step as a material may be carried out.

[0053] Among these processes, the chlorination process includes, for example, a method using hydrogen chloride water (hydrochloric acid) (hydrogen chloride water method), a method using hydrogen chloride gas (hydrogen chloride gas method), a method using chlorine gas (chlorine gas method), and a method using ammonium chloride (ammonium chloride method). Among these, the hydrogen chloride water method is relatively preferable. By using the hydrogen chloride water method, it is likely possible to efficiently chlorinate oxides while removing carbon contained in the combustion ash 41. Note that the chlorination process may be performed by combining the hydrogen chloride water method with the hydrogen chloride gas method, the chlorine gas method, and / or the ammonium chloride method. On the other hand, the molten salt electrolysis process is a process for refining metals using the chlorides produced in the chlorination process as a material. A specific method for this molten salt electrolysis process includes, for example, a procedure in which chlorides are heated to a temperature equal to or higher than the melting point of the chlorides in a molten salt electrolysis bath (e.g., a brick furnace) to melt the chlorides. [Explanation of symbols]

[0054] 1...generator, 2...boiler, 3...hopper, 4...chute, 5...drying stoker, 6...combustion stoker, 7...post-combustion stoker, 8...combustion ash recovery section, 11, 12...fuel holding section (first holding section, second holding section), 11a, 11b, 12b...supply port, 21...combustion chamber, 21A...main combustion chamber, 21b...air blowing section, 21B...flue, 22...superheater, 23...steam turbine, 31...cyclone, 33...air preheater, 33a...straight pipe section, 33b...air intake inlet section, 34...dust collector, 34...blower, 41...combustion ash, 100, 200...power generation system, 120...processing machine, EG, EG'...exhaust gas, F...mixed fuel, F1...organic fuel, F2...inorganic fuel, FU...condenser, G2...raw material, IG...inert gas, J...junction, K...air, N...re-combustion section, P...feedwater pump, P1, P2...piping (first pipe, second pipe), P3 to P6...piping, PU...exhaust pipe, S1, S2...shutter, V...steam, W...water

Claims

1. A boiler apparatus comprising: a combustion chamber; and a fuel supply unit having a first holding unit for holding an organic fuel and a second holding unit for holding an inorganic fuel, the fuel supply unit adjusts a delivery state of the organic fuel from the first storage unit and a delivery state of the inorganic fuel from the second storage unit so as to supply at least a portion of the mixed fuel obtained by mixing the organic fuel and the inorganic fuel to the combustion chamber when at least one of the following conditions is satisfied: (1) before a predetermined time has elapsed since mixing, (2) before the mixed fuel reaches a predetermined temperature, and (3) before the amount of vapor generated from the mixed fuel reaches a predetermined amount; The organic fuel contains carbon or hydrocarbons, the inorganic fuel is carbon- and hydrocarbon-free and contains metals and / or metal hydrides; The second holding unit has a processing unit that processes the metal and / or metal hydride raw material into the inorganic fuel while holding the metal and / or metal hydride raw material in an atmosphere containing an inert gas. Boiler equipment.

2. 2. The boiler apparatus according to claim 1, wherein at least one of the predetermined time, the predetermined temperature, and the predetermined amount of steam is determined based on at least one parameter selected from the amounts of the organic fuel and the inorganic fuel, the reactivity between the organic fuel and the inorganic fuel, the mixing ratio of the organic fuel and the inorganic fuel, the supply rate of the mixed fuel to the combustion chamber, and the properties of the organic fuel and the inorganic fuel.

3. 3. The boiler apparatus according to claim 1, wherein the fuel supply unit has a first pipe connecting one of the first holding unit and the second holding unit to the combustion chamber, and a second pipe connecting the other of the first holding unit and the second holding unit to the first pipe.

4. 4. The boiler apparatus according to claim 3, wherein a distance between the junction of the first pipe and the second pipe and the combustion chamber and / or a supply rate of the mixed fuel to the combustion chamber are determined based on at least one of the predetermined time, the predetermined temperature, and the predetermined amount of steam.

5. The inorganic fuel comprises at least one selected from the group consisting of lithium, boron, magnesium, aluminum, and calcium, and lithium hydride, boron hydride, magnesium hydride, aluminum hydride, and calcium hydride; The boiler apparatus according to claim 1 or 2.

6. A method for operating a boiler apparatus including a combustion chamber, a fuel supply unit having a first holding unit that holds an organic fuel containing carbon or hydrocarbons, and a second holding unit that holds an inorganic fuel that does not contain carbon or hydrocarbons and contains a metal and / or metal hydride, and that includes a processing unit, comprising: adjusting a delivery state of the organic fuel from the first storage unit and a delivery state of the inorganic fuel from the second storage unit so that at least a portion of the mixed fuel obtained by mixing the organic fuel and the inorganic fuel is supplied to the combustion chamber when at least one of the following conditions is satisfied: (1) before a predetermined time has elapsed since mixing, (2) before the mixed fuel reaches a predetermined temperature, and (3) before the amount of vapor generated from the mixed fuel reaches a predetermined amount; The processing unit processes the metal and / or metal hydride raw material into the inorganic fuel while maintaining the raw material in an atmosphere containing an inert gas. How to operate a boiler system.

7. 7. The method for operating a boiler apparatus according to claim 6, wherein at least one of the predetermined time, the predetermined temperature, and the predetermined amount of steam is determined based on at least one parameter selected from the amounts of the organic fuel and the inorganic fuel, the reactivity between the organic fuel and the inorganic fuel, the mixing ratio of the organic fuel and the inorganic fuel, the supply rate of the mixed fuel to the combustion chamber, and the properties of the organic fuel and the inorganic fuel.

8. The boiler apparatus according to claim 1 or 2; a generator that generates electricity using steam generated by the boiler device; A power generation system comprising:

Images