Fluid material circulation device, boiler facility, and method of operating fluid material circulation device

Abstract

To provide a fluidized material circulating device capable of simultaneously discharging a used fluidized material outside a system and replenishing an unused fluidized material and preventing the unused fluidized material from being discharged outside the system prior to being supplied to a fluidized bed boiler.SOLUTION: A fluidized bed boiler 100 comprises: a return line 210 guiding a fluidized material discharged from the fluidized bed boiler 100 to a replenishing part 230 into which an unused fluidized material is charged; and a supply line 220 supplying the fluidized material from the replenishing part 230 to the fluidized bed boiler 100, wherein the return line 210 has a discharge point 215 capable of discharging the fluidized material outside, and the discharge point 215 is disposed upstream relative to the replenishing part 230.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a fluid material circulation device, a boiler facility, and a method for operating a fluid material circulation device. [Background technology]

[0002] A circulating fluidized bed boiler (CFB boiler, CFB: Circulating Fluidized Bed) is known that improves combustion efficiency by fluidizing fuel and fluidizing material (for example, particles mainly composed of SiO2 such as silica sand) in a furnace using air supplied from the bottom of the furnace to form a fluidized bed (for example, Patent Document 1). Furthermore, for example, Patent Document 2 describes a device that includes a circulation path that removes foreign matter from sand (fluidized material) discharged from an industrial waste incinerator and returns it to the incinerator, an external discharge path that branches off from the circulation path, and a switching gate that switches paths, and that controls the bed height level of the fluidized bed inside the furnace by operating the switching gate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 60-122603 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-81627 Summary of the Invention [Problem to be solved by the invention]

[0004] Recently, biomass fuel, a carbon-neutral fuel, has been increasingly used as fuel for fluidized bed boilers. In fluidized bed boilers that use biomass fuel, alkali metals such as sodium and potassium contained in the biomass fuel tend to concentrate as the fluidizing material circulates, lowering the melting point of the combustion ash. This makes it easier for ash to adhere to the heat transfer parts of the fluidized bed boiler, raising concerns about reduced heat transfer efficiency and corrosion. To prevent the alkali metal from concentrating, it is necessary to discharge the circulating fluid material from the system at a predetermined frequency, and to compensate for the discharged fluid material, it is necessary to replenish unused fluid material as needed.

[0005] As disclosed in Patent Document 2, operation using a switching gate installed in the fluid material path does not allow for the discharge of used fluid material from the system and the replenishment of unused fluid material at the same time, and if the discharge and replenishment of fluid material are to be performed at a specified frequency, this may pose a constraint on the operation of the fluidized bed boiler. Furthermore, if a device replacing the switching gate is used to simultaneously discharge used fluid material from the system and replenish unused fluid material, there is a risk that the unused fluid material will be discharged from the system before being supplied to the fluidized bed boiler, which could result in increased operating costs due to an increase in the amount of unused fluid material used.

[0006] The present disclosure has been made in consideration of the above circumstances, and aims to provide a fluid material circulation device, boiler equipment, and method of operating a fluid material circulation device that can simultaneously discharge used fluid material outside the system and replenish unused fluid material, and that does not discharge unused fluid material outside the system before it is supplied to a fluidized bed boiler. [Means for solving the problem]

[0007] In order to solve the above problems, the fluid material circulation system, boiler equipment, and method of operating the fluid material circulation system of the present disclosure employ the following means. In other words, a fluid material circulation device according to one embodiment of the present disclosure comprises a return line that guides fluid material discharged from a fluidized bed boiler to a supply section where unused fluid material is input, and a supply line that supplies fluid material from the supply section to the fluidized bed boiler, the return line having a discharge point where the fluid material can be discharged to the outside, and the discharge point being located upstream of the supply section.

[0008] A boiler facility according to one aspect of the present disclosure includes a fluidized bed boiler connected to the supply line and the return line of the fluidized bed boiler, which burns fuel in the flowing fluidized bed.

[0009] A method for operating a fluid material circulation device according to one aspect of the present disclosure adds unused fluid material to the bin when the amount of fluid material stored in the bin is less than a predetermined amount. [Effects of the Invention]

[0010] According to the present disclosure, the discharge of used fluid material from the system and the replenishment of unused fluid material can be performed simultaneously, and the unused fluid material is not discharged from the system before being supplied to the fluidized bed boiler. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic configuration diagram of a boiler facility according to an embodiment of the present disclosure. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a fluidized material circulation system, a boiler facility, and an operating method of a fluidized material circulation system according to an embodiment of the present disclosure will be described with reference to FIG. It should be noted that the terms "upstream" and "downstream" used in the following description are based on the direction in which the flow material is transported / flowing.

[0013] <Outline of boiler equipment> The boiler facility 1 includes a fluidized bed boiler 100, a fluid material circulation device 200, a supply line 310, and a control unit 400.

[0014] The fluidized bed boiler 100 is a device that fluidizes the fluidizing material and fuel inside the furnace by blowing an oxidizing gas (e.g., air) into the furnace as a fluidizing gas, and then mixes and combusts them to generate high-temperature combustion gas. Examples of flow materials include particles mainly composed of SiO2, such as silica sand. An example of fuel is one that contains biomass (hereinafter referred to as biomass fuel). Biomass is made from, for example, wood or palm kernel shells. Another example of fuel is one that contains waste (hereinafter referred to as waste fuel). Waste is made from, for example, paper sludge, waste tires, dewatered sludge, municipal solid waste, etc.

[0015] <Configuration of fluid material circulation device> The fluidized bed boiler 100 is connected to a fluid material circulation device 200 . The fluid material circulation device 200 is a device that removes foreign matter from the used fluid material discharged from the bottom of the fluidized bed boiler 100 (the fluid material that has been supplied to the fluidized bed boiler 100 at least once and then discharged from the fluidized bed boiler 100), and supplies the fluid material to the fluidized bed boiler 100 while replenishing it with unused fluid material or discharging the used fluid material outside the system as necessary. Foreign matter contained in the used fluid material is removed by equipment (for example, a screening device) (not shown) provided in the fluid material circulation device 200.

[0016] The fluid material circulation device 200 includes a return line 210, a supply line 220, and a bin 230 as a supply section.

[0017] The return line 210 is a line that guides the used fluid material discharged from the bottom of the fluidized bed boiler 100 to the bin 230. Therefore, a first end (upstream end) of the return line 210 is connected to the bottom of the fluidized bed boiler 100, and a second end (downstream end) of the return line 210 is connected to the top of the bin 230.

[0018] The return line 210 is provided with a bed ash cooler 211 . The bed ash cooler 211 is a device that cools and transports the used fluid material discharged from the bottom of the fluidized bed boiler 100. The rotation speed of the bed ash cooler 211 is variable and is adjusted by the control unit 400 provided in the boiler facility 1. This makes it possible to adjust the amount of fluid material guided to the bin 230 via the return line 210.

[0019] The control unit 400 is configured with, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and a computer-readable storage medium, etc. A series of processes for realizing various functions is stored in the storage medium, etc., in the form of a program, for example, and the CPU reads this program into the RAM, etc., and executes information processing and arithmetic processing, thereby realizing various functions. The program may be installed in advance in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or distributed via wired or wireless communication means, etc. Computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, semiconductor memories, etc.

[0020] The return line 210 is provided with a valve 218 . The valve 218 is located downstream of a discharge point 215 (described below) and upstream of a bin 230 . The opening and closing of the valve 218 is controlled by the control unit 400 . The valve 218 may be opened and closed manually by an operator.

[0021] The bin 230 is a container for storing the fluid material. The fluid material stored in the bin 230 includes used fluid material and unused fluid material. By providing the bin 230, the flowable material can be temporarily stored. As previously mentioned, the end of the return line 210 is connected to the top of the bin 230, while the supply line 220 is connected to the bottom of the bin 230.

[0022] The supply line 220 is a line that guides and supplies the fluid material stored in the bin 230 to the fluidized bed boiler 100. Therefore, a first end (upstream end) of the supply line 220 is connected to the bottom of the bin 230, and a second end (downstream end) of the supply line 220 is connected to the fluidized bed boiler 100.

[0023] By connecting the fluid material circulation device 200 to the fluidized bed boiler 100 in this manner, the fluid material basically circulates through the fluidized bed boiler 100, return line 210, bin 230, supply line 220, and fluidized bed boiler 100 in that order. In addition, in order to discharge fluid material that has been used for a certain period of time (used fluid material that has been repeatedly circulated) outside the system and to replenish unused fluid material, the fluid material circulation device 200 is provided with a means for discharging used fluid material outside the system (outside the fluid material circulation device 200) and a means for replenishing unused fluid material into the system.

[0024] A supply line 310 is connected to the bin 230 as a means for supplying unused fluid material (fluid material that has never been used) to the system. The supply line 310 is a line that supplies unused flowable material to the bin 230 . A first end (upstream end) of the supply line 310 is connected to a supply device (not shown), and a second end (downstream end) of the supply line 310 is connected to the top of the bin 230. This allows unused fluid material to be replenished to the bin 230 or to the fluid material circulation device 200 via the bin 230 .

[0025] Here, the supply device is a device that can supply unused fluid material to the supply line 310. An example of the supply device is a powder / granular material transport vehicle (air pressure transport vehicle). By adjusting the operation time and supply capacity of the supply device, the amount of unused fluid material fed into bin 230 via supply line 310 can be adjusted.

[0026] The supply line 310 is provided with a valve 318 . The opening and closing of the valve 318 is controlled by the control unit 400 . Valve 318 is open when a supply device is connected to the first end of supply line 310 (when virgin flowable material is being supplied to bin 230) and is closed when a supply device is connected (when virgin flowable material is not being supplied to bin 230). The valve 318 may be opened and closed manually by an operator.

[0027] The return line 210 is provided with a discharge point 215 as a means for discharging the spent fluid material out of the system. The discharge point 215 is located downstream from the bed ash cooler 211 and upstream from the bin 230 . The discharge point 215 is a point for discharging the fluid material being transported by the return line 210 to the outside of the fluid material circulation device 200.

[0028] A discharge line 320 is connected to the discharge point 215 . The discharge line 320 is a line that guides the fluid material discharged from the return line 210 to the outside of the system via the discharge point 215. Therefore, a first end (upstream end) of the discharge line 320 is connected to the discharge point 215, and a second end (downstream end) of the discharge line 320 is located outside the fluid material circulation device 200. As a result, the used fluid material is discharged from the fluid material circulation device 200 to the outside of the system via the return line 210 and the discharge line 320 .

[0029] The discharge line 320 is provided with a valve 328 . The opening and closing of the valve 328 is controlled by the control unit 400 . Valve 328 is opened when used fluid material is to be discharged outside the system, and is closed when used fluid material is not to be discharged outside the system (when used fluid material is to be guided to bin 230). When used fluid material is to be discharged outside the system, the amount of fluid material discharged outside the system via discharge line 320 can be adjusted by adjusting the time that valve 328 is open. The valve 328 may be opened and closed manually by an operator.

[0030] <<Operating method of fluid material circulation device (discharge of fluid material)>> In order to discharge the used fluid material outside the system, the control unit 400, for example, closes the valve 218 provided in the return line 210 and opens the valve 328 provided in the discharge line 320, or notifies the operator that the valve 218 should be closed and the valve 328 should be opened, thereby urging the operator to operate the valves 218 and 328. As a result, the spent fluid material is no longer guided to the bin 230 via the return line 210, and the spent fluid material is discharged to the outside of the system via the discharge line 320.

[0031] At this time, the discharge point 215 to which the discharge line 320 is connected is disposed upstream of the bin 230, so that the unused fluid material fed into the bin 230 via the supply line 310 does not pass through the discharge point 215 before being supplied to the fluidized bed boiler 100. Therefore, the unused fluid material is not discharged outside the system before being supplied to the fluidized bed boiler 100.

[0032] Furthermore, since the discharge point 215 connected to the discharge line 320 is located upstream of the bin 230, there is no restriction on the timing of discharging the used fluid material discharged from the fluidized bed boiler 100 to the outside of the system. Therefore, for example, the discharge of the used fluid material to the outside of the system and the replenishment of unused fluid material can be performed simultaneously. If discharge point 215 is located downstream of bin 230, in order to prevent unused fluid material from being included in the fluid material discharged from discharge point 215 to the outside of the system, used fluid material cannot be discharged from discharge point 215 to the outside of the system until all unused fluid material input into bin 230 has passed through discharge point 215. In other words, it is necessary to wait for the used fluid material to be discharged until the unused fluid material has passed through discharge point 215, which places constraints on the operation of boiler equipment 1.

[0033] When using waste fuel, there is less concern about the concentration of alkali metals such as sodium and potassium, so the fluid material is discharged from the system less frequently than when using biomass fuel. Therefore, the problem of unused fluid material being discharged from the system before being supplied to the fluidized bed boiler 100 can be said to have a particularly large impact when using biomass fuel. Furthermore, when using waste fuel, it is necessary to increase the circulation volume of the fluid material (i.e., increase the circulation speed of the fluid material) in order to remove foreign matter contained in the fuel (e.g., bead wires generated when using waste tires as fuel) from the fluid material. On the other hand, since the amount of foreign matter contained in biomass fuel is less than the amount of foreign matter contained in waste fuel, when using biomass fuel, it is not necessary to increase the circulation volume of the fluid material (i.e., the circulation speed of the fluid material is slow). Therefore, the restriction that used fluid material cannot be discharged from discharge point 215 to the outside of the system until all unused fluid material input into bin 230 has passed through discharge point 215 can be said to have a particularly large impact when using biomass fuel.

[0034] Used fluid material is discharged from the system, for example, when the concentration of alkali metals such as sodium and potassium that are entrained in the fluid material by adhering thereto (the amount of alkali metals per unit weight of the fluid material) exceeds a predetermined value, or when it is predicted that the concentration will exceed a predetermined value. At this time, the timing of the discharge from the system may be set by actually measuring the concentration, or the timing of the discharge from the system may be set based on the elapsed time from the start of operation or the elapsed time from the previous discharge from the system.

[0035] <<How to operate the fluid material circulation system (supplying fluid material)>> Bin 230 is provided with an amount detector 231 for measuring the amount of the stored flowable material. The amount detection unit 231 is, for example, a level meter that measures the level of the fluid material stored in the bin 230 or a weight meter that measures the weight of the fluid material stored in the bin 230. The information (measured value) from the amount detection unit 231 is transmitted to the control unit 400.

[0036] Based on this information, the control unit 400 determines whether the amount of fluid material stored in the bin 230 is less than a predetermined amount or greater than or equal to a predetermined amount. If the control unit 400 determines that the amount of fluid material is less than a predetermined amount, it determines that unused fluid material needs to be added to the bin 230. Here, the predetermined amount is, for example, an amount necessary to operate the boiler equipment 1 for at least one day.

[0037] When the control unit 400 determines that virgin fluid material needs to be added to the bin 230, it opens the valve 318 provided on the supply line 310, or notifies an operator that the valve 318 should be opened, urging the operator to operate the valve 318. At this time, it is assumed that a supply device that supplies virgin fluid material is connected to a first end of the supply line 310. This results in the introduction of virgin flowable material into bin 230 via supply line 310 . The valve 318 is normally closed and is opened only when virgin fluid material is introduced.

[0038] <Variation 1> Each line may transport the flowable material in any manner. For example, the transport may be by using a conveyor such as a belt conveyor, bucket conveyor, or screw conveyor, or by airflow transport using a gas such as compressed air, or by gravity transport utilizing the free fall of the flowable material, or a combination of these.

[0039] <Variation 2> The bin 230 for storing the flowable material may be omitted, and the return line 210 and the supply line 310 may simply be joined together. In this case, the junction of the return line 210 and the supply line 310 serves as a supply section in place of the bin 230. The supply line 220 is then connected to this supply section. In this case, the return line 210 and the supply line 220 may be considered to be a substantially continuous line. However, the positional relationship between the supply section and the discharge point 215 of the return line 210 remains unchanged. That is, the discharge point 215 is disposed upstream of the supply section where the unused flowable material is introduced.

[0040] <Variation 3> Instead of the valve 218 of the return line 210 and the valve 318 of the discharge line 320, for example, a three-way valve may be provided at the branch point (corresponding to the discharge point 215 in FIG. 1 ) between the return line 210 and the discharge line 320. In this case, the three-way valve is controlled by the control unit 400.

[0041] According to this embodiment, the following effects are achieved. The return line 210 has a discharge point 215 that can discharge the fluid material to the outside, and the discharge point 215 is located upstream of the supply unit (bin 230), so that the unused fluid material fed into the supply unit does not pass through the discharge point 215 before being supplied to the fluidized bed boiler 100. Therefore, the unused fluid material is prevented from being discharged to the outside (outside the system) of the return line 210 before being supplied to the fluidized bed boiler 100, and the amount of unused fluid material used can be reduced. Furthermore, there is no restriction on the timing of discharging the used fluid material discharged from the fluidized bed boiler 100 to the outside of the system. Therefore, for example, it is possible to simultaneously discharge the used fluid material to the outside of the system and replenish unused fluid material, thereby eliminating operational restrictions on the boiler equipment 1. If the discharge point 215 is located downstream of the replenishing section, in order to prevent unused fluid material from being included in the fluid material discharged to the outside of the system from the discharge point 215, the fluid material cannot be discharged to the outside of the system from the discharge point 215 until all of the unused fluid material fed to the replenishing section has passed through the discharge point 215.

[0042] The supply unit is configured as bin 230 capable of storing fluid material, so that fluid material (used fluid material and unused fluid material) can be temporarily stored. This enables operation of the fluidized bed boiler 100 in consideration of the balance between the amount of used fluid material discharged outside the system and the amount of unused fluid material replenished, such as by adding unused fluid material while monitoring the amount of fluid material stored in bin 230 and the amount of fluid material circulating throughout the system.

[0043] When the amount of fluid material stored in the bin 230 is less than a predetermined amount, unused fluid material can be added to the bin 230, making it easier to manage the timing of replenishing the unused fluid material.

[0044] The embodiment described above can be understood, for example, as follows.

[0045] The fluid material circulation device (200) according to the first aspect of the present disclosure includes a return line (210) that guides the fluid material discharged from a fluidized bed boiler (100) to a supply section (230) where unused fluid material is input, and a supply line (220) that supplies the fluid material from the supply section (230) to the fluidized bed boiler (100). The return line (210) has a discharge point (215) that can discharge the fluid material to the outside, and the discharge point (215) is located upstream of the supply section (230).

[0046] The return line (210) has a discharge point (215) that can discharge the fluid material to the outside, and the discharge point (215) is located upstream of the supply unit (230), so that unused fluid material fed to the supply unit (230) does not pass through the discharge point (215) before being supplied to the fluidized bed boiler (100). This prevents the unused fluid material from being discharged to the outside (outside the system) of the return line (210) before being supplied to the fluidized bed boiler (100), thereby reducing the amount of unused fluid material used. In addition, there is no restriction on the timing of discharging the used fluid material discharged from the fluidized bed boiler (100) to the outside of the system. Therefore, for example, discharging the used fluid material to the outside of the system and replenishing unused fluid material can be performed simultaneously. If the discharge point (215) is located downstream of the supply unit (230), in order to prevent unused fluid material from being included in the fluid material discharged from the discharge point (215) to the outside of the system, the fluid material cannot be discharged from the discharge point (215) to the outside of the system until all of the unused fluid material fed to the supply unit (230) has passed through the discharge point (215), which places a restriction on the timing of discharging the used fluid material to the outside of the system.

[0047] In the fluid material circulation device (200) according to the second aspect of the present disclosure, in the first aspect, the supply unit (230) is a bin (230) capable of storing the fluid material.

[0048] The supply unit (230) is a bin (230) capable of storing fluid material, and thus can temporarily store the fluid material (used fluid material and unused fluid material). This allows the fluidized bed boiler (100) to be operated in a manner that takes into consideration the balance between the amount of used fluid material discharged outside the system and the amount of unused fluid material replenished, for example, by adding unused fluid material while monitoring the amount of fluid material stored in the bin (230) and the amount of fluid material circulating throughout the system.

[0049] A boiler facility (1) according to a third aspect of the present disclosure includes the fluidized bed boiler (100) connected to the supply line (220) and the return line (210) of the fluidized bed boiler (200) and configured to combust fuel in the flowing fluidized bed material.

[0050] A fourth aspect of the present disclosure provides a boiler facility (1) according to the third aspect, wherein the fuel for the fluidized bed boiler (100) is biomass fuel.

[0051] A method for operating a fluid material circulation device (200) according to a fifth aspect of the present disclosure is a method for operating a fluid material circulation device (200) according to the second aspect, in which unused fluid material is added to the bin (230) when the amount of fluid material stored in the bin (230) is less than a predetermined amount.

[0052] When the amount of fluid material stored in the bin (230) is less than a predetermined amount, unused fluid material is simply added to the bin (230), making it easier to manage the timing of replenishing the unused fluid material. [Explanation of symbols]

[0053] 1. Boiler equipment 100 Fluidized bed boiler 200 Fluid circulation equipment 210 Return Line 211 Bed Ash Cooler 215 Discharge point 218 Valve 220 Supply Line 230 Bin (Supply Department) 231 Quantity detection unit 310 Supply Line 318 Valve 320 Discharge Line 328 Valve 400 control section

Claims

1. a return line for leading the fluid material discharged from the fluidized bed boiler to a supply section where unused fluid material is introduced; a supply line for supplying fluid material from the supply unit to the fluidized bed boiler; Equipped with the return line has a discharge point through which the flowable material can be discharged to the outside; The discharge point is located upstream of the supply unit. Fluid circulation device.

2. The supply unit is a bin capable of storing the flowable material. The fluid material circulating device according to claim 1.

3. The fluid material circulating device according to claim 1; the fluidized bed boiler connected to the supply line and the return line of the fluidized material circulation device and combusting fuel in the flowing fluidized material; Equipped with Boiler equipment.

4. The fuel for the fluidized bed boiler is biomass fuel. The boiler facility according to claim 3.

5. A method for operating the fluid material circulating apparatus according to claim 2, comprising: When the amount of fluid material stored in the bin is less than a predetermined amount, unused fluid material is poured into the bin. A method for operating a fluid material circulation device.

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