Ash slurry conveying facility

Abstract

To provide an ash slurry conveyance facility capable of generating ash slurry having an appropriate water content with a simpler configuration.SOLUTION: The ash slurry conveyance equipment 1 includes a silo 10 for storing coal ash, a pump P1 for supplying water for generating ash slurry, a stirring tank 40 for stirring coal ash and water to generate ash slurry, an ash flow path T1 through which the coal ash can flow from the silo 10 to the stirring tank 40, an ash flow rate adjustment part 20 having an ash flow rate adjustment gate 22 for opening and closing the ash flow path T1 and capable of adjusting the flow rate of the coal ash, a discharge flow path T3 for discharging the ash slurry generated in the stirring tank 40 to an ash disposal site, a measurement part 50 capable of measuring the density of the ash slurry in the discharge flow path T3, and a control part 601 for controlling the operation of the ash flow rate adjustment gate 22 based on the measurement result of the density of the ash slurry by the measurement part 50 and related information associating the density of the ash slurry with the water content ratio of the ash slurry.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an ash slurry transport system. [Background technology]

[0002] Conventionally, a known method for treating coal ash at coal-fired power plants involves adding water to powdered coal ash to produce ash slurry, and transporting the ash slurry to an ash disposal site. Patent Document 1 illustrates this type of technology. Patent Document 1 describes equipment in which fly ash (coal ash) stored in an ash disposal silo (silo) is supplied to a stirring tank, the fly ash is mixed with water to produce a high-concentration fly ash slurry (ash slurry), and the slurry is transported to the ash disposal site (ash disposal site) for landfill disposal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-284346 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the water content of the ash slurry to which water has been added is low, the fluidity of the ash slurry may deteriorate, which may cause clogging of the conveying equipment, so it is conceivable to adjust the water content of the ash slurry by controlling the mixture ratio of coal ash and water, as in the conveying equipment described in Patent Document 1. However, there is room for improvement in that the configuration of the conveying equipment for controlling the mixture ratio of coal ash and water becomes complicated.

[0005] An object of the present invention is to provide an ash slurry transport facility that can produce ash slurry with an appropriate moisture content with a simpler configuration. [Means for solving the problem]

[0006] (1) The ash slurry transport equipment of the present invention includes a silo for storing coal ash, a water supply unit for supplying water for generating ash slurry, an agitation tank for generating ash slurry by agitating the coal ash supplied from the silo and the water supplied from the water supply unit, an ash flow path connecting the silo and the agitation tank and allowing the coal ash stored in the silo to flow from the silo to the agitation tank, an ash flow rate adjustment unit disposed in the ash flow path and having a gate for opening and closing the ash flow path and capable of adjusting the flow rate of the coal ash passing through the ash flow path by opening and closing the gate, a discharge flow path connected to the agitation tank and for discharging the ash slurry generated in the agitation tank to an ash disposal site, a measurement unit capable of measuring the density of the ash slurry in the discharge flow path, and a control unit for controlling the operation of the gate based on the measurement results of the ash slurry density by the measurement unit and related information correlating the density of the ash slurry for each true density of ash with the moisture content of the ash slurry.

[0007] The ash slurry transport equipment (1) can produce ash slurry with an appropriate moisture content with a simpler configuration.

[0008] (2) In the ash slurry conveying equipment described in (1), the control unit executes an initial control mode in which the control unit controls the opening and closing operation of the gate of the ash flow rate adjustment unit so that the gate of the ash flow rate adjustment unit is opened to a predetermined degree for a predetermined time period from immediately after the coal ash stored in the silo starts to be supplied to the stirring tank, and a normal control mode in which the control unit controls the opening and closing operation of the gate of the ash flow rate adjustment unit based on the measurement result of the moisture content of the ash slurry by the measurement unit after a predetermined time period has elapsed from immediately after the coal ash stored in the silo starts to be supplied to the stirring tank.

[0009] (2) The ash slurry conveying equipment can produce ash slurry with an appropriate moisture content with a simpler configuration while controlling the opening and closing of the gate appropriately, even when the density of the ash slurry is unstable, such as immediately after the coal ash begins to flow into the mixing tank.

[0010] (3) In the ash slurry conveying equipment described in (1) or (2), the control unit acquires information on the set range of the density of the ash slurry and controls the opening and closing operation of the ash flow rate adjustment unit so that the measurement result of the density of the ash slurry by the measurement unit falls within the set range.

[0011] (3) The ash slurry transport equipment can appropriately control the opening and closing of the gate simply by obtaining the measurement results of the ash slurry density, making it possible to produce ash slurry with an appropriate moisture content with an even simpler configuration.

[0012] (4) The ash slurry transport equipment described in (3) further includes an ash property information acquisition unit that acquires property information of coal ash, and the control unit acquires information on the setting range corresponding to the property information based on the property information acquired by the ash property information acquisition unit, and controls the opening and closing operation of the ash flow rate adjustment unit so that the measurement result of the density of the ash slurry by the measurement unit falls within the setting range corresponding to the property information.

[0013] (4) The ash slurry transport equipment can produce ash slurry with an appropriate moisture content with a simpler configuration while controlling the opening and closing of the gate appropriately according to the various properties of coal ash.

[0014] (5) The ash slurry transport equipment described in (3) or (4) further includes an output unit capable of outputting warning information, and the control unit causes the output unit to output warning information when the measurement result by the measurement unit falls outside the set range.

[0015] (5) The ash slurry transport equipment allows workers to quickly recognize the situation and respond to the trouble even if the moisture content of the ash slurry falls outside the set range due to an unexpected problem, etc., so that it is possible to more reliably prevent clogging of the ash slurry transport equipment, etc., while producing ash slurry with an appropriate moisture content with a simpler configuration. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a block diagram showing an ash slurry transport facility according to an embodiment of the present invention. FIG. [Figure 2]1 is a block diagram showing a hardware configuration of a control device according to an embodiment of the present invention; [Figure 3] 2 is a block diagram showing the functional configuration of a control device according to an embodiment of the present invention; FIG. [Figure 4] 1 is a flowchart illustrating an ash slurry transport method using ash slurry transport equipment according to an embodiment of the present invention. [Figure 5] 1 is a flowchart illustrating a normal control mode of an ash slurry transport method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] <Ash slurry transport equipment> An ash slurry transport facility 1 according to one embodiment of the present invention will be described below with reference to Fig. 1. As shown in Fig. 1, the ash slurry transport facility 1 is a facility for adding water to coal ash generated in a boiler to generate ash slurry, and transporting the ash slurry to an ash disposal site.

[0018] The ash slurry transport equipment 1 has a silo 10, an ash flow rate adjustment section 20, a humidification section 30, an agitation tank 40, a measurement section 50, a control device 60, an ash flow path T1, a water supply flow path T2, a discharge flow path T3, a circulation flow path T4, a pump P1 as a water supply section, and an ash slurry pump P2.

[0019] The silo 10 stores fine coal ash generated from the boiler, mainly from the flue. The silo 10 is also called a fly ash storage silo.

[0020] The ash flow rate adjusting unit 20 has a gate and is configured to be able to adjust the flow rate of coal ash passing through the ash flow path T1 by opening and closing the gate. The ash flow rate adjusting unit 20 has a segment gate 21 and an ash flow rate adjusting gate 22 as a gate.

[0021] The segment gate 21 is disposed at the bottom of the silo 10 and serves to block coal ash flowing through the ash passage T1 at the bottom of the silo 10. Therefore, the ash flow rate adjuster opens the segment gate to start supplying coal ash stored in the silo to the agitation tank. An initial control mode, which will be described later, is executed when the segment gate opens.

[0022] The ash flow rate adjusting gate 22 is disposed in the ash flow path T1, which will be described later, and is a gate that opens and closes the ash flow path T1. Specifically, the ash flow rate adjusting gate 22 is a gate that limits the area through which coal ash passes through the ash flow path T1. The ash flow rate adjusting gate 22 may be a gate with an air slider that slides using air pressure. The ash flow rate adjusting gate 22 can manually adjust the amount of coal ash supplied by remote control.

[0023] The gate of the ash flow rate adjusting unit 20 is not limited to this. For example, the ash flow rate adjusting unit 20 may have a gate that combines the functions of the segment gate 21 and the ash flow rate adjusting gate 22, or may have a gate separate from the segment gate 21 and the ash flow rate adjusting gate 22.

[0024] The humidifying unit 30 is disposed in the ash flow path T1 (described later) and is configured to humidify coal ash supplied from the silo. More specifically, the humidifying unit 30 has a two-shaft paddle mixer that humidifies and mixes the coal ash with water that is approximately 20% of the ash weight. The humidifying unit 30 is also called a dustless unloader.

[0025] The agitation tank 40 is configured to generate ash slurry by agitating coal ash supplied from the silo 10 with water supplied from a pump P1 (described later). Specifically, the agitation tank 40 is charged with humidified ash humidified in the humidifying unit 30 and water in an amount that is approximately 80% of the weight of the remaining coal ash, and agitates them. The agitation tank 40 has an agitator (not shown) for agitating the coal ash and water. Note that the ash slurry transport facility 1 may not have the humidifying unit 30, and instead may charge and agitate water in an amount that is approximately 100% of the weight of the coal ash in the agitation tank 40.

[0026] The measuring unit 50 performs measurements to control the opening and closing of the gate of the ash flow rate adjusting unit 20 in the ash slurry conveying equipment 1. Specifically, the measuring unit 50 can measure the density of the ash slurry in the discharge flow path T3 described below. Specifically, the measuring unit 50 has a known density meter provided in the circulation flow path T4 described below, which is connected to the discharge flow path T3, and measures the density of the ash slurry using the density meter. It is preferable that the measuring unit 50 has high maintainability and measurement reliability, and it is preferable that the density meter included in the measuring unit 50 is of a non-contact type. In this case, the density meter of the measuring unit 50 can be prevented from being worn by the ash slurry.

[0027] The control device 60 is configured to control various operations of the ash slurry transport facility. An example of the hardware configuration of the control device 60 will be described with reference to Fig. 2. As shown in Fig. 2, the control device 60 includes a processor 600, a ROM (Read Only Memory) 601, a RAM (Random Access Memory) 602, a bus 603, an input / output interface 604, an input unit 605, an output unit 606, an auxiliary storage device 607, a communication unit 608, and a power supply 609.

[0028] The processor 600 is a central part of a computer that performs various calculations, controls, and other processes required for the operation of the control device 60. The processor 600 is, for example, a central processing unit (CPU), a micro processing unit (MPU), a system on a chip (SoC), a digital signal processor (DSP), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field-programmable gate array (FPGA). Alternatively, the processor 600 may be a combination of two or more of these. The processor 600 may also be a combination of these with a hardware accelerator or the like.

[0029] The processor 600 controls each unit to realize various functions of the control device 60 based on programs such as firmware, system software, and application software stored in the ROM 601, RAM 602, etc. The processor 600 executes processing based on the programs. Note that part or all of the programs may be incorporated into the circuitry of the processor 600.

[0030] The processor 600, ROM 601, and RAM 602 are connected to one another via a bus 603. An input / output interface 604 is also connected to this bus 603. An input unit 605, an output unit 606, an auxiliary storage device 607, a communication unit 608, and a power supply 609 are connected to the input / output interface 604.

[0031] The input unit 605 and the output unit 606 are user interfaces electrically connected to the input / output interface 604 by wire or wirelessly. The input unit 605 is composed of, for example, a keyboard, a mouse, etc., and inputs various information, such as commands to start or stop supplying coal ash to the ash slurry transport facility 1, in response to user instructions. The output unit 606 is composed of a display for displaying images and a speaker for amplifying audio, and outputs images and audio. For example, the output unit 606 can output warning information about the density of the ash slurry using a display, a speaker, etc. The output unit 606 may also display the moisture content converted from the density of the ash slurry. In this case, it is possible to facilitate monitoring by an operator of the ash slurry transport facility 1.

[0032] The auxiliary storage device 607 is configured with a hard disk drive (HDD), a solid state drive (SSD), etc. The auxiliary storage device 607 stores various information such as programs related to various processes and setting values. The auxiliary storage device 607 stores various information such as association information associating the density of the ash slurry with the moisture content of the ash slurry for each true density of the coal ash, property information of the coal ash, and programs.

[0033] The related information is information that enables the moisture content of the ash slurry to be calculated based only on the measurement result of the density of the ash slurry, and specifically, is information that associates the density of the ash slurry with the moisture content of the ash slurry for each true density of the coal ash. More specifically, the related information is information that indicates the relationship between the density of the ash slurry and the moisture content of the ash slurry for each of a plurality of true densities.

[0034] For example, the density of ash slurry when the water content is about 100% by mass is 3 / h, and the true density of coal ash is 2.0t / m 3 When the ash flow rate is 35m 3 / h, the calculation is as follows: Density of ash slurry = Weight of ash slurry / Flow rate of ash slurry = 140t / 105m 3 =1.333t / m 3 Therefore, if the true density of coal ash is 2.0 t / m 3 The moisture content of the ash slurry is approximately 100% by mass, and the density of the ash slurry is 1.333t / m 3 are associated with each other and stored in the auxiliary storage device 607. In addition, since the density of the ash slurry corresponding to a predetermined moisture content varies depending on the true density of the coal ash, the moisture content of the ash slurry and the density of the ash slurry are associated with each other and stored for each of a plurality of true densities.

[0035] The true density of coal ash is often 2.0 t / m 3 ~2.2t / m 3 Therefore, the relevant information is, for example, 3 A correspondence table showing the moisture content of multiple ash slurries within the range of 100 mass% ± 20 mass% and the corresponding ash slurry densities, and a table showing the true density of coal ash of 2.1 t / m 3 In this case, 2.2t / m 3and a similar correspondence table for cases (1) and (2). Therefore, the density of the ash slurry and the moisture content of the ash slurry are determined in advance for each true density of coal ash and stored as related information in the auxiliary storage device 607. In the ash slurry transport equipment 1 according to this embodiment, the true density of coal ash is usually within this range, and the moisture content can be controlled to a predetermined range close to 100% by mass based on the density of the ash slurry.

[0036] The ash slurry transport equipment 1 may handle multiple coal ashes with different properties such as true density, and the moisture content of the ash slurry corresponding to the density of the ash slurry varies depending on the true density of the coal ash used to generate the ash slurry.

[0037] The true density of coal ash is 2.0t / m 3 ~2.2t / m 3 In the case of the range, in order to control the moisture content of the ash slurry at about 100 mass%, the true density of the coal ash must be below the lower limit of 2.0 t / m 3 The density of the ash slurry in this case and the true density of the coal ash are upper limits of 2.2 t / m 3 The density of the ash slurry is calculated based on the relevant information. If the true density of coal ash is 2.0 t / m 3 The density of the ash slurry when the true density of the coal ash is 2.2t / m 3 The ash slurry densities are 1.333t / m and 1.333t / m, respectively. 3 , 1.375t / m 3 Therefore, the ash slurry transport equipment 1 can reduce the density of the ash slurry to 1.333 t / m 3 ~1.375t / m 3 The ash slurry density range is controlled as a set range.

[0038] For example, when the moisture content is set so as not to exceed the ash slurry density range, if the true density of the actual coal ash is 2.0 t / m 3 , ash slurry density range is 1.333t / m 3 ~1.375t / m 3 When the true density of coal ash is 2.1 t / m, the moisture content is 84% ​​to 100% by mass. 3 , ash slurry density range is 1.333t / m 3 ~1.375t / m3 When the true density of actual coal ash is 2.2 t / m, the moisture content is 92% to 109% by mass. 3 , ash slurry density range is 1.333t / m 3 ~1.375t / m 3 In this case, the water content is 100% by mass to 118% by mass.

[0039] Furthermore, as described above, the ash slurry transport equipment 1 may handle multiple types of coal ash, and as the range of true densities of the coal ash handled becomes wider, the range of moisture content of the ash slurry corresponding to the density of the ash slurry also becomes wider. Therefore, in this embodiment, it is assumed that the true density of coal ash can be estimated to some extent depending on, for example, the type of coal, and the true density can be limited. Therefore, coal ash property information, which is information on the range of true density for each coal type, is compiled into a database and stored in the auxiliary storage device 607. The property information is information on the range of true density of coal ash set for each type of coal ash stored in the silo 10, and the ash slurry transport equipment 1 according to this embodiment controls the true density by limiting it based on the property information.

[0040] For example, the property information is that the true density of coal type A is 2.0 t / m 3 ~2.1t / m 3 The true density of coal type B is 2.1t / m 3 ~2.2t / m 3 In this way, by limiting the range of true density, it becomes easy to narrow the range of the moisture content of the ash slurry and bring the moisture content close to approximately 100% by mass. Note that the ash slurry transport facility 1 may have a measuring unit capable of measuring the true density of the coal ash stored in the silo 10 instead of the database.

[0041] The communication unit 608 is a device that enables the processor 600 to communicate with other devices such as the segment gate 21 of the ash flow rate adjustment unit 20, the ash flow rate adjustment gate 22, the humidification unit 30, the pump P1, the ash slurry pump P2, the stirring tank 40, and the measurement unit 50 via a network not shown.

[0042] The power supply 609 is connected to, for example, an external power supply and supplies power to the control device 60. Note that the configuration of the power supply 609 is not limited to this, and the power supply 609 may have a battery and be configured to be able to supply power to each unit of the control device 60.

[0043] Next, the functional configuration of the control device 60 will be described with reference to Fig. 3. A control unit 610, which is a functional configuration of the control device 60 that executes various controls of the control device 60, is realized by a processor 600 that executes arithmetic processing by executing programs stored in a ROM 601, a RAM 602, an auxiliary storage device 607, etc.

[0044] As shown in Figure 3, the control unit 610 of this embodiment has an ash flow rate adjustment control unit (ash flow rate adjustment control function) 611, a humidification control unit (humidification control function) 612, a pump control unit (pump control function) 613, a stirring tank control unit 614, an ash property information acquisition unit (ash property information acquisition function) 615, an ash slurry density range acquisition unit (ash slurry density range acquisition function) 616, a measurement result acquisition unit (measurement result acquisition function) 617, and an output processing unit (output processing function) 618.

[0045] The ash flow rate adjustment control unit 611 controls the opening and closing operations of the segment gate 21 and the ash flow rate adjustment gate 22 of the ash flow rate adjustment unit 20. The ash flow rate adjustment control unit 611 can, for example, control the opening and closing of the segment gate 21, and the initial control mode and normal control mode of the ash flow rate adjustment gate 22.

[0046] The initial control mode is a mode in which the ash flow rate adjusting gate 22 is opened at a predetermined opening degree for a predetermined time until the density of the ash slurry stabilizes, since it takes some time from the start of coal ash supply until the change in density of the ash slurry stabilizes. For example, when the initial control mode is executed, the ash flow rate adjustment control unit 611 controls the opening and closing operation of the ash flow rate adjusting gate 22 of the ash flow rate adjusting unit 20 so that the ash flow rate adjusting gate 22 of the ash flow rate adjusting unit 20 is opened at a predetermined opening degree for a predetermined time immediately after the start of supplying coal ash stored in the silo 10 to the agitation tank 40. The predetermined time is set depending on the amount of ash discharged, which varies depending on the ash properties and the ash storage level. The predetermined time is set, for example, between 30 and 60 minutes. The predetermined opening degree is set based on the amount of ash that will result in a set moisture content, based on the performance curves of the segment gate 21, the ash flow rate adjusting gate 22, etc. The predetermined opening degree is set, for example, to 58% of full opening when the set moisture content is 100% by mass. However, the predetermined time and predetermined opening degree are not limited thereto.

[0047] The normal control mode is a process for controlling the operation of the ash flow rate adjusting gate 22 based on the measurement result of the ash slurry density by the measurement unit 50 and related information correlating the ash slurry density for each true density of coal ash with the moisture content of the ash slurry. Specifically, the ash slurry density range acquisition unit 616 generates information on the ash slurry density range as a set range, and the ash flow rate adjusting unit 20 controls the opening / closing operation of the ash flow rate adjusting gate 22 so that the measurement result of the ash slurry density by the measurement unit 50 falls within the ash slurry density range. More specifically, the normal control mode is a process for controlling the opening / closing operation of the ash flow rate adjusting unit 20 so that the measurement result of the ash slurry density by the measurement unit 50 falls within the ash slurry density range generated by the ash slurry density range acquisition unit 616 based on the coal ash property information acquired by the ash property information acquisition unit 615.

[0048] More specifically, the ash flow rate adjustment control section 611 of the control section 610 controls the ash flow rate adjustment gate 22 so that the measurement result of the measurement section 50 approaches a density value corresponding to a moisture content of approximately 100 mass %. For example, when the true density of coal ash is 2.0 t / m 3 ~2.2t / m 3In this case, in order to control the moisture content of the ash slurry to be about 100 mass%, the measurement result of the measuring unit 50 is 1.333 to 1.375 t / m 3 The ash flow rate adjusting gate 22 is controlled so that the density is

[0049] That is, when the normal control mode is executed, the ash flow rate adjustment control unit 611 of the control unit 610 controls the operation of the ash flow rate adjustment gate 22 based on the measurement results of the ash slurry density by the measurement unit 50 and related information relating the density of the ash slurry to the moisture content of the ash slurry.

[0050] When the normal control mode is executed, the ash flow rate adjustment control unit 611 executes the normal control mode in which, immediately after the start of supplying the coal ash stored in the silo 10 to the mixing tank 40 and a predetermined time has elapsed, the ash flow rate adjustment control unit 611 controls the opening and closing operation of the ash flow rate adjustment gate 22 of the ash flow rate adjustment unit 20 based on the measurement results of the moisture content of the ash slurry by the measurement unit 50.

[0051] In the ash slurry conveying equipment 1 of this embodiment, the opening and closing operation of the ash flow rate adjustment gate 22 can be controlled based on the moisture content, making it easy for managers and operators of the ash slurry conveying equipment 1 to monitor the operation of the ash slurry conveying equipment 1.

[0052] The minimum moisture content required to improve landfill efficiency at an ash disposal site is 100% by mass. If the moisture content is below this, problems such as piping clogging with ash slurry may occur. For example, if the ash slurry transport equipment 1 is operated for a long period of time at a moisture content of 95% or 90% by mass, the piping may become clogged. Therefore, the ash slurry transport equipment 1 controls the opening and closing operation of the ash flow rate adjustment gate 22 so that the moisture content is at least 100% by mass.

[0053] When a manager or operator is assigned to monitor whether the ash slurry transport equipment 1 is malfunctioning, the manager or operator can determine the risk of malfunction, such as clogging of the ash slurry, based on whether the moisture content is below 100% by mass. This makes it easier for the manager or operator of the ash slurry transport equipment 1 to monitor the operation of the ash slurry transport equipment 1. Furthermore, when not managing based on moisture content, for example, when managing based on density, it is not possible to immediately determine whether the measurement results are good or bad. However, when managing based on moisture content, it is possible to immediately determine whether the measurement results are good or bad, making it possible to respond immediately to malfunctions, etc., of the ash slurry transport equipment 1.

[0054] The humidification control unit 612 controls the humidification operation of the humidifier 30 on the coal ash.

[0055] The pump control unit 613 controls the operation of the pump P1 and the ash slurry pump P2.

[0056] The stirring vessel control unit 614 controls the operation of the stirrer in the stirring vessel 40 .

[0057] The ash property information acquisition unit 615 executes a process of acquiring property information of coal ash stored in the above-mentioned auxiliary storage device 607. As described above, the property information is information on the true density of coal ash corresponding to each of a plurality of coal types handled by the ash slurry transport equipment 1. Note that, if the ash slurry transport equipment 1 has a measurement unit capable of measuring the true density of coal ash stored in the silo, the ash property information acquisition unit 615 may acquire the property information from the measurement unit.

[0058] The ash slurry density range acquisition unit 616 acquires the related information stored in the auxiliary storage device 607, and performs a process of generating ash slurry density range information from the acquired related information based on the property information acquired by the ash property information acquisition unit 615.

[0059] The measurement result acquisition unit 617 executes a process for acquiring the measurement results from the measurement unit 50 .

[0060] The output processing unit 618 controls the operation of the output unit 606. The output processing unit 618 of the control unit 610 causes the output unit 606 to output warning information when the measurement result by the measurement unit 50 is outside the ash slurry density range.

[0061] The ash flow path T1 connects the inside of the silo 10 with the inside of the agitation tank 40, and is a known pipe that allows coal ash stored in the silo 10 to flow from the silo 10 to the agitation tank 40. Specifically, the ash flow path T1 connects the inside of the silo 10 with the inside of the agitation tank 40 via the ash flow rate adjuster 20 and the humidifier 30. More specifically, the ash flow path T1 connects the inside of the silo 10 with the inside of the agitation tank 40 via the segment gate 21 and the ash flow rate adjustment gate 22 of the ash flow rate adjuster 20 and the humidifier 30.

[0062] The water supply flow path T2 is a known pipe that connects the seawater with the stirring tank 40. Specifically, the water supply flow path T2 connects the seawater with the stirring tank 40 via a pump P1, which will be described later. Note that the connection destination of the water supply flow path T2 is not limited to seawater. For example, the connection destination of the water supply flow path T2 may be connected to a tank that stores surplus water such as rainwater, a river, a water supply system, or the like.

[0063] The discharge flow path T3 is a known pipe that connects the inside of the agitation tank 40 with the ash disposal area and discharges the ash slurry produced in the agitation tank 40 to the ash disposal area. The circulation flow path T4 is a known pipe that connects the middle part of the discharge flow path T3 with the inside of the agitation tank 40 and circulates the ash slurry from the middle part of the discharge flow path T3 into the agitation tank 40.

[0064] The pump P1 is configured to supply water for producing ash slurry. The pump P1 is a known pump provided in the water supply flow path T2 and sucks seawater toward the agitation tank 40. The ash slurry pump P2 is a known pump provided in the discharge flow path T3 and sucks a portion of the ash slurry stored in the agitation tank 40 toward an ash disposal site and sucks the remaining portion of the ash slurry into the agitation tank 40 via the circulation flow path T4 for density measurement of the ash slurry. If the water supply flow path T2 is connected to a tank or the like that stores surplus water such as rainwater, the pump P1 may suck the rainwater stored in the tank or the like as supply water.

[0065] <Ash slurry transport method> Next, the details of the ash slurry conveying method and the normal control mode executed by the ash slurry conveying equipment 1 according to this embodiment will be described with reference to FIGS.

[0066] In the ash slurry transport method and normal control mode according to this embodiment, as shown in Fig. 3, the processor 600 functions as an ash flow rate adjustment control unit 611, a humidification control unit 612, a pump control unit 613, a stirring tank control unit 614, an ash property information acquisition unit 615, an ash slurry density range acquisition unit 616, a measurement result acquisition unit 617, and an output processing unit 618. The ash slurry transport method executed by the ash slurry transport equipment 1 starts when the ash flow rate adjustment control unit 611 of the control unit 610 receives a command to open the segment gate 21.

[0067] First, the control unit 610 starts various operations for supplying coal ash (step S10). For example, the ash flow rate adjustment control unit 611 controls the ash flow rate adjustment unit 20 to open the segment gate 21. The humidification control unit 612 starts the operation of the humidification unit 30. The coal ash that has passed through the segment gate 21 is humidified by the humidification unit 30 and flows into the agitation tank 40 via the ash flow path T1.

[0068] The pump control unit 613 also starts the operation of the pump P1 and the ash slurry pump P2. Therefore, the pump P1 starts to suck seawater into the agitation tank 40 through the water supply passage T2. The agitation tank control unit 614 starts to control the operation of the agitator in the agitation tank 40. Therefore, the coal ash from the ash passage T1 and the water from the water supply passage T2 are mixed by the agitator, and ash slurry is generated.

[0069] The generated ash slurry is sucked into discharge flow path T3 by the suction of ash slurry pump P2. A portion of the ash slurry sucked into discharge flow path T3 is circulated to an ash disposal site via discharge flow path T3, and the remaining portion is directed to measurement section 50 via circulation flow path T4. The density of the ash slurry circulated into circulation flow path T4 is measured in measurement section 50, and the ash slurry is circulated again to stirring tank 40 via circulation flow path T4.

[0070] Next, the ash flow rate adjustment control unit 611 executes the initial control mode and opens the ash flow rate adjustment gate 22 at a predetermined opening degree for a predetermined period of time (step S11). Next, the control unit 610 checks whether a predetermined time has elapsed (step S12). If the predetermined time has not elapsed (step S12: NO), the control unit 610 repeats the check until the predetermined time has elapsed. If the predetermined time has elapsed (step S12: YES), the ash flow rate adjustment control unit 611 executes the normal control mode (step S13). Details of the normal control mode will be described later.

[0071] The ash flow rate adjustment control unit 611 checks whether a command to end the coal ash supply has been received (step S14). If the command to end the coal ash supply has not been received (step S14: NO), the ash flow rate adjustment control unit 611 repeats the check until the command to end the coal ash supply is received. If the command to end the coal ash supply is received, the control unit 610 stops various operations for the coal ash supply (step S15). For example, the ash flow rate adjustment control unit 611 closes the segment gate 21 and the ash flow rate adjustment gate 22, the humidification control unit 612 stops the operation of the humidification unit 30, the pump control unit 613 stops the operation of the pump P1 and the ash slurry pump P2, and the stirring tank control unit 614 stops controlling the operation of the agitator in the stirring tank 40, thereby completing the ash slurry conveying method performed by the ash slurry conveying equipment 1.

[0072] Next, we will explain the normal control mode executed by the ash flow rate adjustment control unit 611. First, the ash flow rate adjustment control unit 611 causes the ash property information acquisition unit 615 to acquire property information about the coal ash stored in the silo 10, which is stored in the auxiliary storage device 607 (step S20).

[0073] Next, the ash flow rate adjustment control unit 611 causes the ash slurry density range acquisition unit 616 to acquire related information stored in the auxiliary storage device 607, and generates ash slurry density range information from the acquired related information based on the property information acquired by the ash property information acquisition unit 615 (step S21). Next, the ash flow rate adjustment control unit 611 causes the measurement result acquisition unit 617 to acquire the measurement result of the density of the ash slurry by the measurement unit 50 (step S22).

[0074] Next, the ash flow rate adjustment control unit 611 checks whether the measurement result of the density of the ash slurry is within the acquired ash slurry density range (step S23). If the measurement result of the density of the ash slurry is outside the acquired ash slurry density range (step S23: NO), the ash flow rate adjustment control unit 611 controls the opening / closing operation of the ash flow rate adjustment gate 22 so that the measurement result of the density of the ash slurry is within the acquired ash slurry density range (step S24), and proceeds to step S25.

[0075] For example, if the measurement result of the ash slurry density is a value greater than the acquired ash slurry density range, the ash flow rate adjusting gate 22 is controlled to close. On the other hand, if the measurement result of the ash slurry density is a value smaller than the acquired ash slurry density range, the ash flow rate adjusting gate 22 is controlled to open. At this time, the output processing unit 618 may also cause the output unit 606 to output warning information. For example, if a malfunction of the density meter occurs, such as a fixed measurement value, the operator can check the output warning information, which leads to early detection of a malfunction of the ash slurry conveying equipment 1.

[0076] If the measurement result of the density of the ash slurry is within the acquired ash slurry density range (step S23: YES), in step S25, the control unit 610 checks whether a command to end the coal ash supply has been input (step S25). If a command to end the coal ash supply has not been input (step S25: NO), the process proceeds to step S22. The above operation is repeated until a command to end the coal ash supply is input. If a command to end the coal ash supply has been input (step S25: YES), the ash flow rate adjustment control unit 611 ends the normal control mode.

[0077] The ash slurry transport equipment 1 according to the present embodiment described above provides the following advantages. In conventional ash disposal site slurry transport equipment, remote manual adjustments were made by an operator. Specifically, density was measured at the outlet of the mixing tank, and the operator remotely operated a flow rate control gate with an air slider based on the measured density value to adjust the density to a value equivalent to a moisture content of approximately 100% by mass, thereby adjusting the density to fall within a certain range.

[0078] However, conventional methods for adjusting the moisture content of ash slurry require operators to make judgments and operate the controls manually, which can lead to errors in judgment and operation. For example, if the ash flow rate control gate is opened too much, excessive coal ash can be introduced, causing downstream equipment to become clogged and becoming inoperable. There is also the risk of rotating equipment breaking down due to coal ash clogging. On the other hand, if the ash flow rate control gate is opened too little, there is a risk of a shortage of coal ash supply, which can cause delays in the ash treatment plan.

[0079] Furthermore, the conventional method of adjusting the moisture content of ash slurry by remote control requires that the adjustment amount is not constant each time depending on fluctuations in the fly ash storage silo level, which increases the burden of adjustment and monitoring on the operator.

[0080] As in the above-described embodiment, the problem can be solved by automatically controlling the moisture content adjustment method of the ash disposal site slurry transport equipment. Specifically, density is measured at the outlet of the mixing tank. The measured density value is input into the control device, and based on related information, the ash flow rate adjustment gate is automatically controlled to achieve a density value equivalent to a moisture content of approximately 100% by mass.

[0081] In terms of control, since it takes a certain amount of time for the density to change after the coal ash is added, automatic control is not initiated immediately after addition, but rather the ash flow rate adjustment gate is kept at a constant opening until the density stabilizes. Furthermore, once the density stabilizes from a constant opening and reaches a density value equivalent to a moisture content of approximately 100% by mass, automatic control begins.

[0082] During automatic control, a configuration may be provided in which an alarm is issued based on the upper and lower density limits, and an opening limit may be set on the flow rate characteristics of the flow control gate in case of a density meter malfunction, such as a fixed measurement value. This configuration allows for early detection of gate malfunctions. Furthermore, the moisture content converted from density may be displayed on the monitor of the control device 60 or on a central monitoring screen on the network, making it easier for the operator to monitor the data. [Explanation of symbols]

[0083] 1 Ash slurry transport equipment 10 Silo 20 Ash flow rate adjustment section 22 Ash flow rate adjustment gate (gate) 40 Stirring tank 50 Measuring part 610 Control Unit P1 pump (water supply section) T1 ash channel T3 Discharge channel

Claims

1. A silo for storing coal ash, a water supply unit that supplies water for generating ash slurry; a stirring tank that stirs the coal ash supplied from the silo and the water supplied from the water supply unit to generate an ash slurry; an ash flow path connecting the silo and the agitation tank, through which coal ash stored in the silo can flow from the silo to the agitation tank; an ash flow rate adjusting unit that is disposed in the ash flow path, has a gate that opens and closes the ash flow path, and is capable of adjusting the flow rate of coal ash passing through the ash flow path by opening and closing the gate; a discharge flow path connected to the agitation tank for discharging the ash slurry generated in the agitation tank to an ash disposal site; a measuring unit capable of measuring the density of the ash slurry in the discharge flow path; An ash slurry transport facility comprising: a control unit that controls the operation of the gate based on the measurement results of the ash slurry density by the measurement unit and related information that associates the density of the ash slurry for each true density of ash with the moisture content of the ash slurry.

2. 2. The ash slurry transport equipment according to claim 1, wherein the control unit executes an initial control mode in which the control unit controls the opening and closing operation of the gate of the ash flow rate adjustment unit so that the gate is opened to a predetermined degree for a predetermined time period from immediately after the supply of the coal ash stored in the silo to the stirring tank is started, and a normal control mode in which the control unit controls the opening and closing operation of the gate of the ash flow rate adjustment unit based on the measurement result of the moisture content of the ash slurry by the measurement unit after a predetermined time period has elapsed from immediately after the supply of the coal ash stored in the silo to the stirring tank is started.

3. The control unit acquires information on the set range of ash slurry density and controls the opening and closing operation of the ash flow rate adjustment unit so that the measurement result of the ash slurry density by the measurement unit falls within the set range. Ash slurry transport equipment as described in claim 1 or 2.

4. An ash property information acquisition unit that acquires property information of the coal ash is further provided, The control unit acquires information on the setting range corresponding to the property information acquired by the ash property information acquisition unit based on the property information acquired by the ash property information acquisition unit, and controls the opening and closing operation of the ash flow rate adjustment unit so that the measurement result of the density of the ash slurry by the measurement unit falls within the setting range corresponding to the property information.

5. further comprising an output unit capable of outputting warning information; The ash slurry transport facility according to claim 3 , wherein the control unit causes the output unit to output warning information when the measurement result by the measurement unit falls outside the set range.

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