JP2021067408A - Stable operation control system, solid fuel crusher, stable operation control method and stable operation control program - Google Patents

Abstract

To provide a stable operation control system, a solid fuel crusher, a stable operation control method and a stable operation control program capable of continuously performing a stable operation.SOLUTION: A stable operation control system that is applied to a solid fuel crusher 100 including a crushing part 10 crushing solid fuel and an air blowing part 30 supplying conveyance gas to the crushing part 10 includes: a stop section stopping an operation of the crushing part 10 when a flow rate of the conveyance gas supplied to the crushing part 10 reaches less than a predetermined value; and an execution section executing a temperature lowering mode of lowering a temperature of the conveyance gas within a range where the flow rate of the conveyance gas becomes the predetermined value or greater when the temperature of the conveyance gas supplied to the crushing part 10 reaches a threshold value or greater.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a stable operation control system and a solid fuel crusher, a stable operation control method, and a stable operation control program.

Conventionally, a solid fuel (carbon-containing solid fuel) such as coal or biomass fuel is crushed into fine powder within a predetermined particle size range by a crusher (mill) and supplied to a combustion apparatus. The mill crushes solid fuel such as coal and biomass fuel charged into the rotary table by sandwiching it between the rotary table and rollers. Then, the crushed and finely divided fuel is transported to the classifier by the transport gas supplied from the outer circumference of the rotary table. In the classifier, fine powder fuel within a predetermined particle size range is sorted, transported to a boiler, and burned by a combustion device. In a thermal power plant, steam is generated by heat exchange with the combustion gas generated by burning in a boiler, the steam turbine is rotationally driven by the steam, and the generator connected to the steam turbine is rotationally driven to generate electricity. Is done.

In the mill, the fuel is dried together with the transportation (emission) of the fuel by the supplied transportation gas. The transport gas is a mixture of hot gas having a high temperature and cold gas having a low temperature, and the temperature required for drying the fuel and the flow rate required for transporting the fuel are adjusted (for example, Patent Document 1 and Patent Documents). 2).

Japanese Unexamined Patent Publication No. 2018-123993 Japanese Patent No. 5682252

However, when a solid fuel having a high water content (for example, biomass fuel) is used in the mill, the temperature of the transport gas drops significantly due to the heat of vaporization accompanying the drying of the crushed solid fuel, and the transport gas mill outlet. The temperature may drop. In such a case, measures are taken to raise the temperature of the conveyed gas in order to control the temperature at the outlet of the mill. Specifically, since the transport gas is supplied by mixing hot gas and cold gas, a process of increasing the flow rate of the hot gas is performed. However, if the mill inlet temperature of the conveyed gas rises too much, an interlock that stops (cuts off) the supply of hot gas may operate in order to prevent the ignition of solid fuel in the mill. In such a case, since only cold gas is supplied, the flow rate of the conveyed gas decreases, and the operation of the mill is stopped (emergency stop) in order to prevent poor fuel transfer in the mill (fuel accumulation in the mill). ) The interlock may operate and the supply of pulverized fuel obtained by crushing solid fuel may be stopped. In this way, especially for solid fuels with a high water content, as a result of adjusting the transport gas that accompanies the rise in the mill inlet temperature, the flow rate of the transport gas decreases and the interlock operates, which is an interlock operation (protection operation). Chained occurrences can occur. When the operation of the mill is stopped, fuel cannot be supplied to the boiler, which may hinder the stable operation of the power plant, such as a decrease in the boiler output.

The present disclosure has been made in view of such circumstances, and includes a stable operation control system and a solid fuel crusher capable of continuously performing stable operation, a stable operation control method, and a stable operation control program. The purpose is to provide.

The first aspect of the present disclosure is a stable operation control system applied to a solid fuel crushing device including a crushing unit for crushing solid fuel and a blower unit for supplying a transport gas to the crushing unit, and the crushing unit. When the flow rate of the transport gas supplied to the crushed portion is less than a predetermined value, the temperature of the stop portion for stopping the operation of the crushed portion and the temperature of the transported gas supplied to the crushed portion are equal to or higher than the threshold value. The stable operation control system includes an execution unit that executes a temperature reduction mode for lowering the temperature of the transport gas within a range in which the flow rate of the transport gas is equal to or higher than the predetermined value.

The second aspect of the present disclosure is a stable operation control method applied to a solid fuel crushing device including a crushing unit for crushing solid fuel and a blower unit for supplying a transport gas to the crushing unit, and the crushing unit. When the flow rate of the transported gas supplied to the crushed portion is less than a predetermined value, the operation of the crushing portion is stopped, and when the temperature of the transported gas supplied to the crushed portion becomes equal to or higher than the threshold value. This is a stable operation control method including a step of executing a temperature reduction mode for lowering the temperature of the transport gas within a range in which the flow rate of the transport gas is equal to or higher than the predetermined value.

A third aspect of the present disclosure is a stable operation control program applied to a solid fuel crushing apparatus including a crushing unit for crushing solid fuel and a blower unit for supplying a transport gas to the crushing unit. When the flow rate of the transport gas supplied to the crushed portion becomes less than a predetermined value, the operation of the crushing portion is stopped, and when the temperature of the transported gas supplied to the crushed portion becomes equal to or higher than the threshold value. This is a stable operation control program for causing a computer to execute a process of executing a temperature reduction mode for lowering the temperature of the transported gas within a range in which the flow rate of the transported gas is equal to or higher than the predetermined value.

According to the present disclosure, there is an effect that stable operation can be continuously performed.

It is a block diagram which shows the solid fuel crushing apparatus and the boiler which concerns on one Embodiment of this disclosure. It is a hardware block diagram of the control part which concerns on one Embodiment of this disclosure. It is a functional block diagram which showed the function which the control part which concerns on one Embodiment of this disclosure has. It is a figure which showed the flowchart of the temperature reduction mode execution processing by the control part which concerns on one Embodiment of this disclosure. It is a figure which showed the flow of operation in a reference example.

Hereinafter, a stable operation control system and a solid fuel crusher, a stable operation control method, and an embodiment of a stable operation control program according to the present disclosure will be described with reference to the drawings. In this embodiment, a case where the stable operation control system is applied to the solid fuel crusher 100 of the power plant 1 will be described.

The power plant 1 according to the present embodiment includes a solid fuel crusher 100 and a boiler 200.

The solid fuel crusher 100 of the present embodiment crushes a solid fuel (carbon-containing solid fuel) such as coal or biomass fuel as an example, generates fine pulverized fuel, and supplies it to the burner portion (combustion device) 220 of the boiler 200. It is a device. The power plant 1 including the solid fuel crushing device 100 and the boiler 200 shown in FIG. 1 includes one solid fuel crushing device 100, and corresponds to each of the plurality of burner portions 220 of the one boiler 200. The system may be provided with a plurality of solid fuel crushing devices 100.

The solid fuel crushing device 100 of the present embodiment includes a mill (crushing unit) 10, a coal feeder (fuel supply machine) 20, a blower unit (conveyed gas supply unit) 30, and a state detection unit (state detection device) 40. And a control unit (control device) 60.
In the present embodiment, "upper" means the direction of the vertically upper side, and "upper" such as the upper part and the upper surface means the part on the vertically upper side. Similarly, "bottom" indicates the part on the vertically lower side.

The mill 10 for crushing solid fuel such as coal or biomass fuel supplied to the boiler 200 into pulverized fuel which is a pulverized solid fuel may be in the form of crushing only coal or crushing only biomass fuel. It may be in the form of crushing biomass fuel together with coal, and the type of solid fuel is not limited. Here, the biomass fuel is a renewable organic resource derived from living organisms, for example, thinned wood, waste wood, drifting wood, grass, waste, sludge, tires, and recycled fuel (pellets and pellets) made from these. Chips), etc., and are not limited to those presented here. Since biomass fuel takes in carbon dioxide during the growth process of biomass, it is considered to be carbon-neutral, which does not emit carbon dioxide, which is a greenhouse gas, and its use is being studied in various ways.

The mill 10 includes a housing 11, a rotary table (table) 12, a roller (crushing roller) 13, a drive unit 14, a rotary classifier (classifier) 16, a fuel supply unit 17, and a rotary classifier. A motor 18 for rotationally driving the 16 is provided.
The housing 11 is formed in a tubular shape extending in the vertical direction, and is a housing that houses a rotary table 12, a roller 13, a rotary classifier 16, and a fuel supply unit 17. A fuel supply unit 17 is attached to the central portion of the ceiling portion 42 of the housing 11. The fuel supply unit 17 supplies the solid fuel guided from the bunker 21 into the housing 11, is arranged at the center position of the housing 11 in the vertical direction, and the lower end portion extends to the inside of the housing 11. ing.

A drive unit 14 is installed near the bottom surface portion 41 of the housing 11, and a rotary table 12 that rotates by a driving force transmitted from the drive unit 14 is rotatably arranged.
The rotary table 12 is a member having a circular shape in a plan view, and is arranged so that the lower ends of the fuel supply unit 17 face each other. The upper surface of the rotary table 12 may have an inclined shape such that the central portion is low and the rotary table 12 is high toward the outside, and the outer peripheral portion may be bent upward. The fuel supply unit 17 supplies solid fuel (for example, coal or biomass fuel in this embodiment) from above to the lower rotary table 12. The rotary table 12 crushes the solid fuel supplied from the fuel supply unit 17 with the rollers 13, and is also called a crushing table.

When the solid fuel is charged from the fuel supply unit 17 toward the center of the rotary table 12, the solid fuel is guided to the outer peripheral side of the rotary table 12 by the centrifugal force due to the rotation of the rotary table 12, and is between the solid fuel and the roller 13. It is sandwiched and crushed. The crushed solid fuel is blown upward by the transport gas (primary air) guided from the transport gas flow path 100a, and is guided to the rotary classifier 16. That is, an outlet (not shown) is provided on the outer periphery of the rotary table 12 to allow the transport gas flowing in from the transport gas flow path 100a to flow out into the space above the rotary table 12 in the housing 11. A vane (not shown) is installed at the air outlet to give a turning force to the conveyed gas blown out from the air outlet. The transport gas to which the swirling force is applied by the vane becomes an air flow having a swirling velocity component, and guides the solid fuel crushed on the rotary table 12 to the upper rotary classifier 16 in the housing 11. Of the crushed solid fuel mixed with the transport gas, those having a particle size larger than the predetermined particle size are classified by the rotary classifier 16 or fall without reaching the rotary classifier 16 and fall on the rotary table. It is returned to 12 and crushed again with the roller 13. That is, the solid fuel is transported to the outlet side (rotary classifier 16) by the transport force of the transport gas.

The roller 13 is a rotating body that crushes the solid fuel supplied from the fuel supply unit 17 to the rotary table 12. The roller 13 is pressed against the upper surface of the rotary table 12 and cooperates with the rotary table 12 to crush the solid fuel. In FIG. 1, only one roller 13 is represented as a representative, but a plurality of rollers 13 are arranged to face each other at regular intervals in the circumferential direction so as to press the upper surface of the rotary table 12. To. For example, the three rollers 13 are arranged at equal intervals in the circumferential direction with an angular interval of 120 ° on the outer peripheral portion. In this case, the portion where the three rollers 13 are in contact with the upper surface of the rotary table 12 (the portion to be pressed) is equidistant from the rotation center axis of the rotary table 12.

The roller 13 can be swung up and down by the journal head 45, and is supported so as to be close to and separated from the upper surface of the rotary table 12. When the rotary table 12 rotates with the outer peripheral surface in contact with the upper surface of the rotary table 12, the roller 13 receives a rotational force from the rotary table 12 and rotates around the roller 13. When the solid fuel is supplied from the fuel supply unit 17, the solid fuel is pressed between the roller 13 and the rotary table 12 and crushed to become fine fuel.

The support arm 47 of the journal head 45 is supported on the side surface of the housing 11 by a support shaft 48 whose intermediate portion is along the horizontal direction so that the roller 13 can swing in the vertical direction around the support shaft 48. Further, a pressing device 49 is provided at the upper end portion on the vertically upper side of the support arm 47. The pressing device 49 is fixed to the housing 11 and applies a load (crushing load) to the roller 13 via the support arm 47 or the like so as to press the roller 13 against the rotary table 12.

The drive unit 14 is a device that transmits a driving force to the rotary table 12 to rotate the rotary table 12 around a central axis (rotary axis). The drive unit 14 generates a driving force for rotating the rotary table 12.

The rotary classifier 16 is provided on the upper part of the housing 11 and has a hollow substantially inverted conical outer shape. The rotary classifier 16 includes a plurality of blades 16a extending in the vertical direction at its outer peripheral position. The blades 16a are provided at predetermined intervals (equal intervals) around the central axis of the rotary classifier 16. Further, in the rotary classifier 16, the solid fuel crushed by the roller 13 is larger than a predetermined particle size (for example, 70 to 100 μm for coal) according to the rotation speed (classifier rotation speed) (hereinafter, a predetermined particle size). A device that classifies crushed solid fuel that exceeds the specified particle size into "coarse powder fuel") and fuel having a predetermined particle size or less (hereinafter, crushed solid fuel having a predetermined particle size or less is referred to as "fine powder fuel"). The rotary classifier 16 that classifies by rotation is also called a rotary separator, and is given a rotational driving force by a motor 18 controlled by a control unit 60 to provide a cylindrical shaft (not shown) extending in the vertical direction of the housing 11. It rotates around the fuel supply unit 17 in the center.

In the crushed solid fuel that has reached the rotary classifier 16, due to the relative balance between the centrifugal force generated by the rotation of the blade 16a and the centripetal force due to the airflow of the conveyed gas, the coarse powder fuel having a large diameter is produced by the blade 16a. It is knocked down, returned to the turntable 12, crushed again, and the pulverized fuel is guided to an outlet 19 at the ceiling 42 of the housing 11.
The pulverized fuel classified by the rotary classifier 16 is discharged from the outlet 19 to the supply flow path 100b, and is transported to the subsequent process together with the transport gas. The pulverized fuel that has flowed out to the supply flow path 100b is supplied to the burner portion 220 of the boiler 200.

The fuel supply unit 17 is attached so that the lower end portion extends vertically to the inside of the housing 11 so as to penetrate the upper end of the housing 11, and the solid fuel input from the upper part of the fuel supply unit 17 is transferred to the rotary table 12. Supply to the approximately central region of. The fuel supply unit 17 is supplied with solid fuel from the coal feeder 20.

The coal feeder 20 includes a transport unit 22 and a motor 23. The transport unit 22 transports the solid fuel discharged from the lower end portion of the down spout portion 24 directly under the bunker 21 by the driving force given from the motor 23, and is guided to the fuel supply unit 17 of the mill 10.
Normally, a transport gas for transporting pulverized solid fuel, which is a crushed solid fuel, is supplied to the inside of the mill 10 at a controlled air volume (transport gas flow rate), and the pressure is increased. Fuel is held in a laminated state inside the down spout portion 24, which is a pipe extending in the vertical direction directly under the bunker 21, and the solid fuel layer laminated in the down spout portion 24 causes the mill 10 side. The sealing property is ensured so that the transport gas and fine fuel do not flow back.
The amount of solid fuel supplied to the mill 10 may be adjusted by the belt speed of the belt conveyor of the transport unit 22.

On the other hand, the biomass fuel chips and pellets before crushing have a constant particle size (the size of the pellets) as compared with coal fuel (that is, the particle size of coal before crushing is, for example, about 2 to 50 mm). Is, for example, about 6 to 8 mm in diameter and about 40 mm or less in length), and is lightweight. Therefore, when the biomass fuel is stored in the down spout portion 24, the gap formed between the biomass fuels becomes larger than that in the case of the coal fuel.
Therefore, since there is a gap between the biomass fuel chips and pellets in the down spout portion 24, the transport gas blown up from the inside of the mill 10 and the fine powder fuel pass through the gap formed between the biomass fuels, and the mill 10 The internal pressure may drop. Further, when the conveyed gas blows through the storage portion of the bunker 21, the transportability of the biomass fuel deteriorates and dust is generated, the bunker 21 and the down spout portion 24 are ignited, and when the pressure inside the mill 10 decreases, the pulverized fuel There is a possibility that various problems may occur in the operation of the mill 10, such as a decrease in the amount of fuel transported. Therefore, a rotary valve (not shown) may be provided in the middle of the fuel supply unit 17 from the coal feeder 20 to suppress the backflow due to the blowing up of the conveyed gas and the pulverized fuel.

The blower unit 30 is a device that dries the solid fuel crushed by the roller 13 and blows the conveyed gas for supplying the rotary classifier 16 to the inside of the housing 11.
In this embodiment, the blower unit 30 uses a primary air ventilator (PAF: Primary Air Fan) 31, a hot gas flow path 30a, and a cold air ventilator (PAF) 31 in order to adjust the temperature of the conveyed gas blown to the housing 11 to an appropriate temperature. It includes a gas flow path 30b, a hot gas damper 30c, and a cold gas damper 30d.

In the present embodiment, the heat gas flow path 30a heats a part of the air (outside air) sent from the primary air ventilator 31 through a heat exchanger (heater) 34 such as an air preheater. It is supplied as heat gas. A hot gas damper 30c (first blower portion) is provided on the downstream side of the hot gas flow path 30a. The opening degree of the heat gas damper 30c is controlled by the control unit 60. The flow rate of the hot gas supplied from the hot gas flow path 30a is determined by the opening degree of the hot gas damper 30c. In the hot gas damper 30c, the flow rate of hot gas increases as the opening degree increases.

The cold gas flow path 30b supplies a part of the air sent out from the primary air ventilator 31 as cold gas at room temperature. A cold gas damper (second blower) 30d is provided on the downstream side of the cold gas flow path 30b. The opening degree of the cold gas damper 30d is controlled by the control unit 60. The flow rate of the cold gas supplied from the cold gas flow path 30b is determined by the opening degree of the cold gas damper 30d. In the cold gas damper 30d, the flow rate of cold gas increases as the opening degree increases.

In the present embodiment, the flow rate of the transport gas is the total flow rate of the hot gas supplied from the hot gas flow path 30a and the flow rate of the cold gas supplied from the cold gas flow path 30b, and the temperature of the transport gas is the hot gas. It is determined by the temperature and mixing ratio of the hot gas supplied from the flow path 30a and the cold gas supplied from the cold gas flow path 30b, and is controlled by the control unit 60.
Further, a part of the combustion gas discharged from the boiler 200 is guided to the hot gas supplied from the hot gas flow path 30a via a gas recirculation ventilator (not shown) to form an air-fuel mixture, thereby forming the conveyed gas flow path 100a. The oxygen concentration of the transport gas flowing in from may be adjusted.

In the present embodiment, the state detection unit 40 of the housing 11 transmits the measured or detected data to the control unit 60. The state detection unit 40 of the present embodiment is, for example, a differential pressure measuring means, and is a portion where the transport gas flows from the transport gas flow path 100a into the inside of the mill 10 and a transport gas and fine powder fuel from the inside of the mill 10 to the supply flow path 100b. The differential pressure with the outlet 19 discharged from the mill 10 is measured as the differential pressure in the mill 10. For example, depending on the classification performance of the rotary classifier 16, the increase / decrease in the circulation amount of the crushed solid fuel that circulates inside the mill 10 between the vicinity of the rotary classifier 16 and the vicinity of the rotary table 12 and the difference in the mill 10 with respect to this. The increase and decrease of pressure changes. That is, since the pulverized fuel discharged from the outlet 19 can be adjusted and managed with respect to the solid fuel supplied to the inside of the mill 10, the particle size of the pulverized fuel does not affect the combustibility of the burner portion 220. A large amount of pulverized fuel can be supplied to the burner portion 220 provided in the boiler 200.
Further, the state detection unit 40 of the present embodiment is, for example, a temperature measuring means, and the temperature of the transport gas supplied to the inside of the housing 11 for blowing the solid fuel crushed by the roller 13 to the rotary classifier 16. , The temperature of the conveyed gas up to the outlet 19 (outlet temperature) is detected inside the housing 11, and the blower portion 30 is controlled so as not to exceed the upper limit temperature. Since the transport gas is cooled by transporting the pulverized product while drying it in the housing 11, the temperature (mill outlet temperature) from the upper space of the housing 11 to the outlet 19 is, for example, about 60 to 80 degrees. It becomes a degree.

The boiler 200 burns using the fine fuel supplied from the solid fuel crusher 100 to generate steam. Therefore, the boiler 200 includes a furnace 210 and a burner portion 220.

The burner section 220 heats the transport gas containing the pulverized fuel supplied from the supply flow path 100b and the air (outside air) sent from the forced air ventilator (FDF: Feed Draft Fan) 32 with the heat exchanger 34. It is a device that forms a flame by burning fine fuel using the supplied secondary air. The pulverized fuel is burned in the furnace 210, and the high-temperature combustion gas is discharged to the outside of the boiler 200 after passing through a heat exchanger (not shown) such as an evaporator, a superheater, and an economizer.

The combustion gas discharged from the boiler 200 is subjected to a predetermined treatment by an environmental device (not shown by a denitration device, an electrostatic collector, etc.), and is sent from the primary air ventilator 31 by a heat exchanger 34 such as an air preheater, for example. The heat is exchanged between the air and the air sent from the forced air ventilator 32, and the air is guided to the chimney (not shown) via the induced draft fan (IDF) 33 and discharged to the outside air. To. The air sent from the primary air ventilator 31 heated by the combustion gas in the heat exchanger 34 is supplied to the hot gas flow path 30a described above.
The water supply to each heat exchanger of the boiler 200 is heated by an economizer (not shown) and then further heated by an evaporator (not shown) and a superheater (not shown) to generate high-temperature and high-pressure steam to generate electricity. It is sent to a steam turbine (not shown), which is a unit, to rotate drive the steam turbine, and a generator connected to the steam turbine (not shown) is driven to rotate to generate electricity, thereby forming a power plant 1.

The control unit 60 is a device that controls each part of the solid fuel crushing device 100. The control unit 60 may control the rotation speed of the rotary table 12 with respect to the operation of the mill 10 by transmitting a drive instruction to the drive unit 14, for example. The control unit 60 adjusts the classification performance by transmitting a drive instruction to the motor 18 of the rotary classifier 16 to control the rotation speed, thereby optimizing the differential pressure in the mill 10 within a predetermined range. It is possible to stabilize the supply of pulverized fuel. Further, the control unit 60 transfers a drive instruction to the motor 23 of the coal feeder 20, for example, so that the transport unit 22 conveys the solid fuel and supplies the solid fuel to the fuel supply unit 17 (coal supply amount). ) Can be adjusted. Further, the control unit 60 can control the opening degree of the hot gas damper 30c and the cold gas damper 30d to control the flow rate and temperature of the conveyed gas by transmitting the opening degree instruction to the blower unit 30. Specifically, the control unit 60 controls the hot gas damper 30c and the cold gas damper 30d so that the flow rate of the conveyed gas and the outlet temperature become predetermined values set for the amount of coal supplied for each solid fuel type. ..

The control unit 60 in the present embodiment prevents an emergency stop (trip) of the operation of the mill 10 from occurring due to a chain decrease in the flow rate of the conveyed gas when the inlet temperature of the mill 10 exceeds the threshold value. Perform the temperature reduction mode (provisional mode). That is, the transport gas is controlled so that the operation can be stably continued without stopping the mill 10. In the present embodiment, the temperature of the transport gas in which the hot gas and the cold gas are mixed and supplied (inflow) to the mill 10 is described as the inlet temperature, and the temperature of the transport gas discharged (outflow) from the mill 10 is described as the inlet temperature. Is described as the outlet temperature. Further, the flow rate of the conveyed gas supplied (inflowing) to the mill 10 is referred to as an inlet flow rate. For example, the inlet temperature is measured by the thermometer 71, and the inlet flow rate is measured by the hygrometer 72.

FIG. 2 is a diagram showing an example of the hardware configuration of the control unit 60 according to the present embodiment.
As shown in FIG. 2, the control unit 60 is a computer system (computer system), for example, a CPU 110, a ROM (Read Only Memory) 120 for storing a program or the like executed by the CPU 110, and when each program is executed. A RAM (Random Access Memory) 130 that functions as a work area, a hard disk drive (HDD) or a solid state drive (SSD) 140 as a large-capacity storage device, and a communication unit 150 for connecting to a network or the like are provided. There is. Each of these parts is connected via a bus 180.

Further, the control unit 60 may include an input unit including a keyboard, a mouse, and the like, a display unit including a liquid crystal display device for displaying data, and the like.

The storage medium for storing the program or the like executed by the CPU 110 is not limited to the ROM 120. For example, it may be another auxiliary storage device such as a magnetic disk, a magneto-optical disk, or a semiconductor memory. Further, the HDD 140 may be replaced with a solid state disk (SSD) or the like.

A series of processing processes for realizing various functions described later is recorded in the HDD (or SSD) 140 or the like in the form of a program, and the CPU 110 reads this program into the RAM 130 or the like to process and calculate information. By executing, various functions described later are realized. The program is installed in ROM 120 or other storage medium in advance, is provided in a state of being stored in a computer-readable storage medium, or is distributed via a wired or wireless communication means. Etc. may be applied. Computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, semiconductor memories, and the like.

Specifically, as shown in FIG. 3, the control unit 60 includes a stop unit 62 and an execution unit 63 as main configurations. That is, the stable operation control system is configured by the stop unit 62 and the execution unit 63, and the conveyed gas is controlled so that the mill 10 can continue the stable operation.

The stop unit 62 stops the operation of the mill 10 when a predetermined condition is satisfied. Therefore, the stop portion 62 has a first stop portion 64 and a second stop portion 65. The first stop unit 64 and the second stop unit 65 stop the operation of the mill 10 according to different conditions.

The first stop unit 64 stops the operation of the mill 10 when the flow rate (inlet flow rate) of the conveyed gas supplied to the mill 10 becomes less than a predetermined value (flow rate abnormality interlock). The transport gas plays a role of transporting (discharging) the crushed solid fuel inside the mill 10. If a sufficient flow rate of the transport gas is not supplied to the mill 10, the transport force from the mill 10 to the burner portion 220 cannot be secured, and the solid fuel (fine powder fuel) after crushing cannot be transported poorly (for example, the supply of the fine powder solid fuel). Sedimentation and deposition in the flow path 100b (pulverized coal pipe), etc.) may occur. If a transport failure occurs, the mill 10 may be overloaded, or the temperature of the pulverized fuel may rise in the pulverized coal pipe, resulting in a malfunction.

Therefore, the first stop unit 64 acquires the flow rate of the conveyed gas from the flow meter 72 installed on the inlet side of the mill 10 as shown in FIG. Then, the first stop unit 64 makes an emergency stop (trip) of the mill 10 when the flow rate of the conveyed gas becomes less than a predetermined value. The predetermined value is set as the flow rate of the transport gas capable of obtaining a predetermined transport force according to, for example, the type of solid fuel (difference in coal type and raw material) and the supply amount (coal supply amount).

Since the mill 10 can be tripped by the first stop unit 64 when the flow rate of the transport gas decreases, it is possible to more reliably suppress the occurrence of transport defects or the like in the mill 10.

In this embodiment, the case where the flow meter 72 is provided as shown in FIG. 1 will be described. However, since it is sufficient that the flow rate of the conveyed gas supplied to the mill 10 can be obtained, the installation position of the flow meter 72 will be described. It is not limited to the installation position shown in FIG. For example, the flow rates in the hot gas flow path 30a and the cold gas flow path 30b may be measured and added together.

The second stop unit 65 stops the operation of the mill 10 when a predetermined condition is satisfied during the temperature reduction mode. The details of the temperature reduction mode will be described later, but it is a mode for improving (lowering the temperature) the high temperature state of the inlet temperature of the conveyed gas. That is, the second stop unit 65 stops the mill 10 for safety when an unstable state of a predetermined operating state is observed while performing the mode for improving the temperature abnormality.

Specifically, the second stop unit 65 is in an unstable state in which the operating state of the boiler 200 that burns using the crushed solid fuel (fine powder fuel) is set in advance while the temperature reduction mode is being executed. In this case, the operation of the mill 10 is stopped. The operating state of the boiler 200 is at least one of the exhaust gas properties of the boiler 200, the boiler main steam temperature, and the boiler main steam pressure.

Regarding the exhaust gas properties of the boiler 200, for example, when the NOx concentration or the CO concentration deviates from a predetermined range, it is determined to be in an unstable state. The boiler main steam temperature is determined to be an unstable state change when the temperature of the main steam at the outlet of the boiler 200 drops to a reference value or less. The reference value is set as a threshold value for the temperature of the main steam of the boiler, which is estimated to be difficult to continue stable operation of the mill 10 based on the correlation between the operating state of the mill 10 and the main steam temperature of the boiler 200. To. The boiler main steam pressure is determined to be in an unstable state when the pressure of the main steam at the outlet of the boiler 200 drops to a reference value or less. The reference value is set as the threshold value of the pressure of the main steam of the boiler, which is estimated to be difficult to continue the stable operation of the mill 10 based on the correlation between the operating state of the mill 10 and the main steam pressure of the boiler 200. To. In this way, the second stop portion 65 determines whether or not the operating state of the boiler 200 is an unstable state based on at least one of the exhaust gas properties of the boiler 200, the boiler main steam temperature, and the boiler main steam pressure. ..

Then, when the second stop portion 65 determines that the operating state of the boiler 200 is in an unstable state due to at least one of the exhaust gas properties of the boiler 200, the boiler main steam temperature, and the boiler main steam pressure. , Stop the operation of the mill 10. As for the operating state of the boiler 200, other than the exhaust gas properties of the boiler 200, the boiler main steam temperature, and the boiler main steam pressure may be used as long as the parameters are related to the operating state of the mill 10.

Further, the second stop unit 65 stops the operation of the mill 10 when the temperature of the conveyed gas discharged from the mill 10 becomes equal to or lower than the dew point during the temperature reduction mode. Since the temperature reduction mode is a mode for lowering the inlet temperature of the transport gas, it also affects the outlet temperature of the transport gas. When the temperature reduction mode is performed, the inlet temperature of the exhaust gas is lowered, so that the outlet temperature of the conveyed gas is also lowered. When the outlet temperature of the transport gas drops below the dew point, dew condensation occurs in the pulverized fuel supply flow path 100b (fine pulverized coal pipe), and the pulverized fuel adheres to the inner surface of the pulverized coal pipe, resulting in poor transport. And pulverized coal pipe blockage may occur.

Therefore, the second stop unit 65 monitors the outlet temperature of the conveyed gas, and stops the operation of the mill 10 when the outlet temperature falls below the dew point. The dew point determination reference value may be calculated from the heat mass balance of the transport gas supplied to the mill 10 and the solid fuel, or may be set to a preset temperature.

In this way, in the second stop unit 65, the operation of the mill 10 can be stopped by the change in the operating state in the temperature reduction mode, so that the operating state of the mill 10 becomes unstable and the unstable state is maintained. It can be suppressed that it is done.

The execution unit 63 provisionally sets a temperature reduction mode in which the temperature of the transport gas is lowered within a range in which the flow rate of the transport gas exceeds a predetermined value when the temperature of the transport gas supplied to the mill 10 exceeds the threshold value. Execute. Specifically, the execution unit 63 temporarily executes the temperature reduction mode by controlling the flow rates of the cold gas and the hot gas constituting the transport gas. Specifically, the opening degree of the cold gas damper (flow rate regulator) 30d is adjusted to control the flow rate of cold gas, and the opening degree of the hot gas damper (flow rate regulator) 30c is adjusted to control the flow rate of hot gas. .. If the flow rates of the cold gas and the hot gas can be controlled, the control is not limited to the damper. The execution unit 63 acquires the temperature measured from, for example, the thermometer 71, and monitors the temperature of the conveyed gas supplied to the mill 10.

For example, if the inlet temperature of the transport gas rises too much, the crushed solid fuel in the mill 10 may ignite. Therefore, when the hot gas damper 30c is fully closed in order to lower the inlet temperature of the transport gas. (The flow rate of cold gas is maintained). However, although the temperature of the transport gas can be reduced by fully closing the hot gas damper 30c, the flow rate of the transport gas as a whole also decreases, and the abnormal flow rate interlock of the transport gas can operate in a chain. There is sex. In particular, when a solid fuel that is easily ignited is used, such as when a biomass fuel is used, the above-mentioned chain interlock operation may occur. Abnormal flow rate of transport gas When the interlock operates, the operation of the mill 10 stops and the supply of fine fuel to the boiler 200 stops, which may hinder stable operation such as a decrease in the output of the power plant 1. In the embodiment, it is decided to provide a corresponding process that does not cause an abnormal interlock in the flow rate of the conveyed gas.

Therefore, when the inlet temperature of the transport gas becomes equal to or higher than the threshold value, the execution unit 63 reduces the inlet temperature of the transport gas by adjusting the temperature and flow rate of the transport gas. In the present embodiment, the case where the execution unit 63 has the three temperature reduction modes will be described, but at least one of the modes may be executed.

Specifically, the execution unit 63 reduces the flow rate of the hot gas in the temperature reduction mode. Further, the execution unit 63 stops the supply of the hot gas and increases the flow rate of the cold gas in the temperature reduction mode. Further, the execution unit 63 increases the flow rate of the cold gas in the temperature reduction mode. In the present embodiment, the temperature reduction mode for increasing the flow rate of cold gas is set to A mode, the temperature reduction mode for reducing the flow rate of hot gas is set to B mode, the supply of hot gas is stopped, and the flow rate of cold gas is increased. The temperature reduction mode is set to C mode.

In the A mode, the cold gas damper 30d is opened by a predetermined opening degree in order to increase the flow rate of the cold gas. Specifically, in the A mode, the cold gas damper 30d is opened by a predetermined opening degree from the opening degree of the cold gas damper 30d before the mode is executed. The opening degree of the heat gas damper 30c before the mode is executed is maintained. In the A mode, the flow rate of the hot gas does not change and the flow rate of the cold gas is increased, so that the temperature of the conveyed gas can be lowered. In the A mode, the flow rate of the hot gas does not change, and the flow rate of the transport gas increases as the flow rate of the cold gas increases. Therefore, the flow rate of the transport gas becomes equal to or higher than a predetermined value and the transport force is secured. Therefore, an abnormal interlock in the flow rate of the conveyed gas does not occur.

In the B mode, the heat gas damper 30c is closed by a predetermined opening degree in order to reduce the flow rate of the heat gas. Specifically, in the B mode, the heat gas damper 30c is closed by a predetermined opening degree from the opening degree of the heat gas damper 30c before the mode is executed. The opening degree of the cold gas damper 30d before the mode is executed is maintained. In the B mode, the flow rate of the cold gas does not change and the flow rate of the hot gas is reduced, so that the temperature of the conveyed gas can be lowered. In the B mode, the flow rate of the hot gas is reduced within the range where the flow rate of the conveyed gas is equal to or higher than a predetermined value. Therefore, even in the B mode, the flow rate of the transport gas becomes equal to or higher than a predetermined value and the transport force is secured, so that the abnormal flow rate interlock of the transport gas does not occur.

In the C mode, in order to stop the supply of hot gas and increase the flow rate of cold gas, the hot gas damper 30c is fully closed and the opening degree of the cold gas damper 30d is opened. Specifically, in the C mode, the opening degree of the hot gas damper 30c is fully closed, and the opening degree of the cold gas damper 30d before the mode is executed is controlled in the direction of opening the cold gas damper 30d. In the C mode, the flow rate of the hot gas is eliminated and only the cold gas is used, so that the temperature of the conveyed gas can be lowered. In the C mode, since the flow rate of the hot gas becomes zero, it is necessary to secure the transport force by the transport gas only with the cold gas. Therefore, in the cold gas damper 30d, an opening range in which the flow rate of the conveyed gas becomes equal to or higher than a predetermined value is set in advance only by the flow rate of the cold gas damper 30d, and the cold gas damper 30d is opened so as to be within the opening range. Therefore, even in the C mode, the flow rate of the transport gas becomes equal to or higher than a predetermined value and the transport force is secured, so that the abnormal flow rate interlock of the transport gas does not occur.

In any of the A mode, the B mode, and the C mode, the temperature of the transport gas can be lowered to lower the inlet temperature of the transport gas, and the transport force due to the flow rate of the transport gas can be secured. Abnormal flow rate of transport gas It is possible to adjust the inlet temperature of transport gas without causing interlock.

The execution unit 63 can execute a plurality of temperature reduction modes, and preferentially executes the temperature reduction mode having a low degree of influence on the decrease in the flow rate of the conveyed gas. The degree of influence on the decrease in the flow rate of the conveyed gas is the degree of difficulty in decreasing the flow rate of the conveyed gas by control. That is, the lower the degree of influence, the more the decrease in the flow rate of the conveyed gas due to the mode execution is suppressed.

In the A mode, since the flow rate of the cold gas is increased, the flow rate of the conveyed gas does not decrease. In the B mode, since the flow rate of the hot gas is reduced, the flow rate of the conveyed gas may be reduced, but the amount of decrease is small. Therefore, the B mode has a higher influence on the decrease in the flow rate of the conveyed gas than the A mode. In the C mode, the supply of the hot gas is stopped and the flow rate of the cold gas is increased, so that the flow rate of the conveyed gas may decrease as compared with the B mode. Therefore, the C mode has a higher influence on the decrease in the flow rate of the conveyed gas than the A mode. That is, the A mode has the lowest influence on the decrease in the flow rate of the conveyed gas (higher priority), and the B mode has the next lowest influence on the decrease in the flow rate of the conveyed gas (the priority is the second highest after the A mode). ), The C mode has the next lowest influence on the decrease in the flow rate of the conveyed gas (the priority is the second highest after the B mode). Therefore, in the present embodiment, the temperature reduction mode is executed in the order of A mode, B mode, and C mode. In addition, each mode may be combined and executed.

Specifically, the execution unit 63 first executes the A mode when performing the temperature reduction mode, and executes the B mode when the inlet temperature of the conveyed gas does not fall below the threshold value due to the A mode. Then, the B mode is executed, and when the inlet temperature of the conveyed gas does not fall below the threshold value due to the B mode, the C mode is executed. Then, the C mode is executed, and when the inlet temperature of the conveyed gas does not fall below the threshold value due to the C mode, the A mode is executed. If the inlet temperature of the conveyed gas does not fall below the threshold value in the C mode, it is estimated that the temperature cannot be effectively reduced by the temperature reduction mode, and the mill does not execute the A mode again. 10 may be stopped.

In this way, the execution unit 63 effectively reduces the inlet temperature of the transport gas while ensuring the transport power of the solid fuel crushed in the mill 10 in each temperature reduction mode. Therefore, it is possible to prevent the operation of the mill 10 from being stopped due to the chain operation of the transfer gas flow rate abnormality interlock due to the temperature abnormality of the inlet temperature of the transfer gas.

Next, an example of the temperature reduction mode execution process by the control unit 60 described above will be described with reference to FIG. FIG. 4 is a flowchart showing an example of the procedure of the temperature reduction mode execution process according to the present embodiment. The flow shown in FIG. 4 is repeatedly executed in a predetermined control cycle, for example, when the solid fuel crusher 100 is in operation.

In the flow of FIG. 4, when the inlet temperature of the conveyed gas of the mill 10 rises, S101 is determined to be YES, and the subsequent processing is executed. When the inlet temperature of the transport gas of the mill 10 rises, for example, when a high-moisture fuel having a high water content is charged into the mill 10 and the outlet temperature of the transport gas drops, the outlet temperature of the transport gas is maintained. This occurs because the temperature of the conveyed gas rises by controlling the hot gas damper 30c to be increased (for example, fully open) and the cold gas damper 30d to be decreased or maintained. It should be noted that the above example is not limited to the case where the inlet temperature of the conveyed gas of the mill 10 rises. When the inlet temperature of the transport gas of the mill 10 rises above the threshold value in this way, the solid fuel may ignite, so that each process of FIG. 4 is executed.

First, it is determined whether or not the inlet temperature of the conveyed gas is equal to or higher than the threshold value (S101). If the inlet temperature of the conveyed gas is not equal to or higher than the threshold value (NO determination in S101), S101 is executed again.

When the inlet temperature of the conveyed gas is equal to or higher than the threshold value (YES determination in S101), the temperature reduction mode is started (S102). In S102, the A mode having a high priority is started.

Next, it is determined whether or not the flow rate of the conveyed gas is equal to or higher than a predetermined value (S103). When the flow rate of the conveyed gas is not equal to or higher than a predetermined value (NO determination in S103), the operation of the mill 10 is stopped (S104). In the temperature reduction mode, the flow rate of the transport gas is controlled to be equal to or higher than a predetermined value, but when the flow rate of the transport gas is reduced due to a cause other than the cold gas flow rate and the hot gas flow rate, S103 is used. The operation of the mill 10 is stopped.

When the flow rate of the conveyed gas is equal to or higher than a predetermined value (YES determination in S103), it is determined whether or not the operating state of the boiler 200 is in a preset unstable state (S105). In S105, for example, it is determined whether or not the operating state of the boiler 200 is an unstable state based on at least one of the exhaust gas properties of the boiler 200, the boiler main steam temperature, and the boiler main steam pressure.

When the operating state of the boiler 200 is in a preset unstable state (YES determination in S105), the operation of the mill 10 is stopped (S104). When the operating state of the boiler 200 is not in a preset unstable state (NO determination in S105), it is determined whether or not the outlet temperature of the conveyed gas is below the dew point (S106).

When the outlet temperature of the conveyed gas is equal to or lower than the dew point (YES determination in S106), the operation of the mill 10 is stopped (S104). When the outlet temperature of the conveyed gas is not equal to or lower than the dew point (NO determination in S106), it is determined whether or not a preset predetermined time has elapsed (S107). The predetermined time is preset as the time for continuing each mode of the temperature reduction mode. For the predetermined time, for example, the allowable duration of decrease in boiler efficiency when each mode is executed, or even if the temperature is equal to or higher than the dew point due to the decrease in the outlet temperature of the conveyed gas, the temperature drops in the middle of the piping route and dew condensation can occur. It is set according to the permissible generation state up to the sex. That is, the duration of each mode is limited to a predetermined time. A predetermined time may be set according to each mode.

In S107, it is determined whether or not the preset predetermined time has elapsed, but it may be determined whether or not the instruction to end the temperature reduction mode has been input by the driver or the like. The instruction to end the temperature reduction mode is input, for example, by pressing the return switch by the driver or the like.

If the preset predetermined time has not elapsed (NO determination in S107), the process returns to S103 and the process is executed again. When the preset predetermined time has elapsed (YES determination in S107), the temperature reduction mode is terminated and restored (S108). Restoration is to return to the flow rate state of cold gas and hot gas before the temperature reduction mode is executed. Specifically, the return returns to the opening degree of the hot gas damper 30c and the opening degree of the cold gas damper 30d before the temperature reduction mode is executed.

Then, it is determined whether or not the inlet temperature of the conveyed gas is equal to or higher than the threshold value (S109). When the inlet temperature of the conveyed gas is not equal to or higher than the threshold value (NO determination in S109), it is estimated that the abnormality of the inlet temperature has been improved by the temperature reduction mode, and the process is terminated. That is, the operation is continued at the opening degree of the hot gas damper 30c and the opening degree of the cold gas damper 30d before the execution of the temperature reduction mode. When the operation is continued, the hot gas damper 30c and the cold gas damper 30d are controlled as in the normal operation.

When the inlet temperature of the conveyed gas is equal to or higher than the threshold value (YES determination in S109), the temperature reduction mode is changed (S110), and the process of S103 is executed again. When the mode is changed, the mode is switched to the lower priority mode and a new mode is started. Specifically, when the processing of S110 is performed after the A mode has been executed, the mode is switched to the B mode, the B mode is started, and the processing is executed again. Further, when the processing of S110 is performed after the B mode has been executed, the mode is switched to the C mode, the C mode is started, and the processing is executed again. In this way, each mode of A mode, B mode, and C mode is continuously executed for a predetermined time. In this way, each mode is switched and executed according to the priority.

For example, when the abnormality of the inlet temperature of the conveyed gas is recovered in S109 as a result of executing the A mode, the continuous operation is performed without performing the B mode or the C mode. Therefore, by preferentially executing the mode that has a low influence on the flow rate of the transport gas, the operating condition is improved while suppressing the occurrence of the abnormal flow rate interlock of the transport gas due to the reduction of the flow rate of the transport gas. It becomes possible.

FIG. 5 is an example of an operation flow when an interlock having an abnormal inlet temperature of the transport gas and an interlock having an abnormal flow rate of the transport gas are provided as reference examples. In the reference example, the interlock with an abnormality in the inlet temperature of the transport gas means that the hot gas damper 30c is fully closed (cold) in order to lower the inlet temperature of the transport gas when the inlet temperature of the transport gas exceeds the threshold value. The gas damper 30d is an operation for maintaining the opening degree). The interlock of the flow rate abnormality of the transport gas in the reference example is an operation of stopping the mill 10 when the flow rate of the transport gas becomes less than the threshold value. As shown in FIG. 5, when the inlet temperature of the transport gas rises due to the injection of high-moisture fuel having a high water content (S201), the interlock of the inlet temperature abnormality of the transport gas operates (S202). Therefore, the heat gas damper 30c is fully closed (S203), and the flow rate of the conveyed gas decreases (S204). Then, the interlock of the abnormal flow rate of the conveyed gas is activated (S205), and the operation of the mill 10 is stopped (S206). In this way, if the temperature of the transport gas is simply lowered when the inlet temperature of the transport gas is abnormal as in the reference example, the interlock of the flow rate abnormality of the transport gas will be activated in a chain reaction, and the mill will be operated. The process of stopping the operation of 10 is executed.

However, according to the process of FIG. 4 as in the present embodiment, when the inlet temperature of the transport gas supplied to the mill 10 exceeds the threshold value, the flow rate of the transport gas is within a range of the predetermined value or more. Since the temperature reduction mode for lowering the temperature of the transport gas is executed, it is possible to prevent the process of stopping the operation of the mill 10 from being executed due to the interlock of the flow rate abnormality of the transport gas being activated in a chain reaction. it can.

As described above, according to the stable operation control system and the solid fuel crushing device, the stable operation control method, and the stable operation control program according to the present embodiment, it is possible to stabilize the operating state of the solid fuel crushing device 100. it can. If the temperature of the transport gas supplied to the mill 10 rises too high, the solid fuel may ignite in the mill 10. Biomass fuel is particularly easy to ignite. However, if the temperature of the transport gas supplied to the mill 10 exceeds the threshold value and the transport gas is adjusted and the control is continued as it is, the flow rate of the transport gas decreases and becomes less than a predetermined value, and the solid in the mill 10. The fuel carrying capacity may decrease. If the carrying capacity of the solid fuel in the mill 10 decreases, the mill 10 may be overloaded, so that the operation of the mill 10 is stopped. The predetermined value is set as a threshold value for stopping the operation of the mill 10 with respect to the flow rate of the transport gas. For example, it is allowed to secure the transport power of the crushed solid fuel by the transport gas in the mill. It is set as the lower limit of the flow rate of the conveyed gas to be carried. Therefore, in the present embodiment, when the temperature of the transport gas supplied to the mill 10 is equal to or higher than the threshold value, the temperature of the transport gas is reduced within a range in which the flow rate of the transport gas is equal to or higher than a predetermined value. By executing the mode (provisional mode for reducing the temperature of the transport gas supplied to the mill 10), the temperature of the transport gas supplied to the mill 10 is lowered while suppressing the decrease in the transport force due to the transport gas. Can be made to. That is, even when the temperature of the transport gas supplied to the mill 10 exceeds the threshold value, the flow rate of the transport gas decreases in a chain reaction to prevent the mill 10 from stopping (mill trip), while suppressing the mill 10 It is possible to improve the operating condition. Therefore, it is possible to contribute to the stable operation of the solid fuel crushing device 100.

When the transport gas is composed of a mixture of cold gas and hot gas, the flow rate and temperature of the transport gas are effectively controlled by controlling the flow rate of the cold gas and the flow rate of the hot gas, respectively, to reduce the temperature. Can be executed.

Multiple temperature reduction modes are set. First, the temperature of the transport gas can be lowered by reducing the flow rate of the hot gas. The amount of decrease in heat gas is set within a range in which the flow rate of the conveyed gas is equal to or higher than a predetermined value. First, the temperature of the conveyed gas can be lowered by stopping the supply of the hot gas and increasing the flow rate of the cold gas. The amount of increase in cold gas is set within a range in which the flow rate of the conveyed gas is equal to or higher than a predetermined value. The other one is that the temperature of the conveyed gas can be lowered by increasing the flow rate of the cold gas. Since the treatment is to increase the cold gas, the flow rate of the conveyed gas is kept above a predetermined value. When a plurality of temperature reduction modes can be executed, the transfer gas is preferentially executed by executing the temperature reduction mode having a low influence on the decrease in the flow rate of the transfer gas (that is, the flow rate of the transfer gas is unlikely to decrease). It is possible to prevent the flow rate of the above value from becoming less than a predetermined value. In addition, it is possible to prevent the flow rate of the transport gas from being excessively lowered in the mill and the transportability and drying property of the crushed solid fuel from being lowered.

Even when the temperature reduction mode is being executed, if the operating state of the boiler 200 becomes a preset unstable state, the operation of the mill 10 is stopped to change the operating state of the power plant 1 and the boiler 200. Sudden changes and failures of the mill 10 can be suppressed. Even when the temperature reduction mode is being executed, if the temperature (outlet temperature) of the conveyed gas discharged from the mill 10 falls below the dew point, the operation of the mill 10 is stopped to cause the power plant 1 and the boiler. It is possible to suppress a sudden change in the operating state of the 200 and a failure of the mill 10.

The present disclosure is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the invention.

In this embodiment, biomass fuel is taken as an example of a solid fuel that is easily ignited, but other solid fuels that are easily ignited may also be applied, and PC (petroleum coke) generated during coal or oil refining may be applied. It can also be applied to solid fuels containing carbon such as fuels.

In the present embodiment, the A mode, the B mode, and the C mode are executed respectively, but each mode may be combined. For example, the opening degree of the hot gas damper 30c may be decreased (reduced hot gas flow rate), and the opening degree of the cold gas damper 30d may be increased (increased cold gas flow rate).

It is preferable that the opening and closing speed (or closing degree) of opening and closing the damper in each mode and the opening / closing speed are appropriately set in advance by a test such as a trial run. Further, it is preferable that the opening / closing speed (or closing degree) of opening / closing the damper in each mode and the opening / closing speed are set according to the type of solid fuel used.

When the temperature reduction mode is performed, the outlet temperature of the conveyed gas tends to decrease. When the outlet temperature of the transport gas decreases, the boiler efficiency may decrease. Further, if the outlet temperature of the conveyed gas is maintained at a low temperature for a long time, the temperature drops in the middle of the piping path and dew condensation occurs even if the dew point or higher is reached in the solid fuel supply flow path 100b (pulverized coal pipe). There is also concern about poor transport and blockage due to the adhesion and growth of pulverized fuel on the inner surface of the pulverized coal pipe. Therefore, it is preferable that the temperature reduction mode is not continued for a long time. Therefore, the execution time of the temperature reduction mode may be limited.

In the A mode, when the cold gas damper 30d is opened, the opening degree of the cold gas damper 30d may be maintained when the inlet temperature of the conveyed gas becomes less than the threshold value.

As for the damper operation command, the opening change signal for each mode may be directly input as the damper opening instruction. That is, immediately before the final damper opening command is output, the opening signal of each mode due to the inlet temperature abnormality of the conveyed gas may be reflected in the opening command of each damper. Further, the opening degree change signal for each mode may be input to another signal that affects the damper opening degree (for example, the outlet temperature set value of the mill 10) to indirectly reflect each mode state. ..

The flow rate adjustment of the hot gas and the cold gas may be performed by any of the flow rate regulators installed in each flow path. For example, when a damper (adjuster) and a gate (switch) are provided in each flow path, either the damper (control damper) or the gate (blocking damper) may be used.

The stable operation control system and the solid fuel crusher, the stable operation control method, and the stable operation control program described in each of the above-described embodiments are grasped as follows, for example.
The stable operation control system according to the present disclosure is applied to a solid fuel crushing device including a crushing unit (10) for crushing solid fuel and a blower unit (30) for supplying a transport gas to the crushing unit (10). A stable operation control system with a stop unit (62) that stops the operation of the crushing unit (10) when the flow rate of the conveyed gas supplied to the crushing unit (10) becomes less than a predetermined value. When the temperature of the transport gas supplied to the crushing unit (10) becomes equal to or higher than the threshold value, the temperature at which the temperature of the transport gas is lowered within the range in which the flow rate of the transport gas becomes equal to or higher than the predetermined value. It includes an execution unit (63) that executes a reduction mode.

If the temperature of the transport gas supplied to the crushing section (10) rises too high, the solid fuel crushed by the crushing section (10) may ignite. Biomass fuel is particularly easy to ignite. On the other hand, when the temperature of the transport gas supplied to the crushing section (10) exceeds the threshold value and the transport gas is adjusted, the flow rate of the transport gas decreases to less than a predetermined value in the crushing section (10). The carrying capacity of the crushed solid fuel may decrease. If the transport capacity of the crushed solid fuel in the crushed portion (10) decreases, the crushed portion (10) may be overloaded, so that the crushed portion (10) is stopped. The predetermined value is set as a threshold value for stopping the operation of the crushing section (10) with respect to the flow rate of the transport gas. For example, the transport of the crushed solid fuel by the transport gas in the crushing section (10). It is set as the lower limit of the flow rate of the conveyed gas allowed to secure the force.

Therefore, when the temperature of the transport gas supplied to the crushing unit (10) exceeds the threshold value, the temperature of the transport gas is tentatively lowered within the range in which the flow rate of the transport gas exceeds a predetermined value. By executing the reduction mode (provisional mode for reducing the temperature of the transport gas supplied to the crushing section (10)), the transport supplied to the crushing section (10) while suppressing the decrease in the transport force due to the transport gas. The temperature of the gas can be lowered. That is, even when the temperature of the transport gas supplied to the crushing section (10) exceeds the threshold value, the flow rate of the transport gas decreases in a chain reaction and the operation of the crushing section (10) is stopped ( It is possible to improve the operating condition while suppressing the mill trip). Therefore, it is possible to contribute to the stable operation of the solid fuel crusher (100).

In the stable operation control system according to the present disclosure, the execution unit (63) may execute the temperature reduction mode by controlling the flow rates of the cold gas and the hot gas constituting the transport gas.

According to the stable operation control system according to the present disclosure, the transport gas is composed of cold gas having a low temperature and hot gas having a high temperature, for example, a part of the air sent from the primary air ventilator. The transport gas is composed of a mixture of cold gas at about room temperature and hot gas that is heated by passing a part of the air sent from, for example, a primary air ventilator through a heat exchanger such as an air preheater. ing. In this case, the temperature reduction mode can be executed by effectively controlling the flow rate and temperature of the conveyed gas by controlling the flow rate of the cold gas and the flow rate of the hot gas, respectively.

In the stable operation control system according to the present disclosure, the execution unit (63) may reduce the flow rate of the hot gas in the temperature reduction mode.

According to the stable operation control system according to the present disclosure, the temperature of the conveyed gas can be lowered by reducing the flow rate of the hot gas. The amount of decrease in the hot gas flow rate is set within a range in which the flow rate of the conveyed gas is equal to or higher than a predetermined value.

In the stable operation control system according to the present disclosure, the execution unit (63) may stop the supply of the hot gas and increase the flow rate of the cold gas in the temperature reduction mode.

According to the stable operation control system according to the present disclosure, in the temperature reduction mode, the supply of the hot gas is stopped and the flow rate of the cold gas is increased.

In the stable operation control system according to the present disclosure, the execution unit (63) may increase the flow rate of the cold gas in the temperature reduction mode.

According to the stable operation control system according to the present disclosure, the temperature of the conveyed gas can be lowered by increasing the flow rate of the cold gas. Since the treatment is to increase the cold gas, the flow rate of the conveyed gas is kept above a predetermined value.

In the stable operation control system according to the present disclosure, the execution unit (63) can execute a plurality of the temperature reduction modes, and preferentially prefers the temperature reduction mode having a low degree of influence on the decrease in the flow rate of the conveyed gas. You may do it.

According to the stable operation control system according to the present disclosure, when a plurality of temperature reduction modes can be executed, the degree of influence on the flow rate reduction of the transport gas is low (that is, the flow rate of the transport gas is unlikely to decrease). By preferentially executing the mode, it is possible to prevent the flow rate of the conveyed gas from becoming less than a predetermined value. In addition, it is possible to prevent the flow rate of the transport gas from being excessively lowered and the transportability and drying property of the crushed solid fuel in the crushed portion (10) from being lowered.

In the stable operation control system according to the present disclosure, in the stop unit (62), the operating state of the boiler (200) that burns using the crushed solid fuel while executing the temperature reduction mode is preset. When the unstable state is reached, the operation of the crushing unit (10) may be stopped.

According to the stable operation control system according to the present disclosure, even when the temperature reduction mode is being executed, if the operating state of the boiler (200) becomes an unstable state set in advance, the crushing unit (10) By stopping the operation, it is possible to suppress a sudden change in the operating state of the power plant (1) and the boiler (200) and a failure of the crushing unit (10).

In the stable operation control system according to the present disclosure, the operating state of the boiler (200) may be at least one of the exhaust gas properties of the boiler (200), the boiler main steam temperature, and the boiler main steam pressure. Good.

According to the stable operation control system according to the present disclosure, the supply state of the crushed solid fuel (fine powder fuel) to the boiler (200) by the crushing unit (10) is the exhaust gas properties of the boiler (200) and the boiler main steam temperature. , And because it affects the boiler main steam pressure, it is effective to change the operating state of the boiler (200) by at least one of the exhaust gas properties of the boiler (200), the boiler main steam temperature, and the boiler main steam pressure. Can be grasped.

In the stable operation control system according to the present disclosure, when the stop unit (62) is executing the temperature reduction mode and the temperature of the conveyed gas discharged from the crushing unit (10) becomes equal to or lower than the dew point. , The operation of the crushing unit (10) may be stopped.

According to the stable operation control system according to the present disclosure, even when the temperature reduction mode is being executed, when the temperature (outlet temperature) of the conveyed gas discharged from the crushing unit (10) becomes equal to or lower than the dew point, By stopping the operation of the crushing unit (10), it is possible to suppress a sudden change in the operating state of the power generation plant (1) and the boiler (200) and a malfunction of the crushing unit (10).

The solid fuel crushing device (100) according to the present disclosure includes a crushing unit (10) for crushing solid fuel, a blower unit (30) for supplying a transport gas to the crushing unit (10), and the stable operation control system described above. And.

The stable operation control method according to the present disclosure is applied to a solid fuel crushing device (100) including a crushing unit (10) for crushing solid fuel and a blower unit (30) for supplying transport gas to the crushing unit (10). In the stable operation control method, the step of stopping the operation of the crushing unit (10) when the flow rate of the conveyed gas supplied to the crushing unit (10) becomes less than a predetermined value, and the above-mentioned A temperature reduction mode in which the temperature of the transport gas is lowered within a range in which the flow rate of the transport gas becomes equal to or higher than the predetermined value when the temperature of the transport gas supplied to the crushing unit (10) becomes equal to or higher than the threshold value. Has a step of performing.

The stable operation control program according to the present disclosure is applied to a solid fuel crushing device (100) including a crushing unit (10) for crushing solid fuel and a blower unit (30) for supplying transport gas to the crushing unit (10). In the stable operation control program to be performed, the process of stopping the operation of the crushing unit (10) when the flow rate of the conveyed gas supplied to the crushing unit (10) becomes less than a predetermined value, and the above-mentioned A temperature reduction mode in which the temperature of the transport gas is lowered within a range in which the flow rate of the transport gas becomes equal to or higher than the predetermined value when the temperature of the transport gas supplied to the crushing unit (10) becomes equal to or higher than the threshold value. And let the computer execute the process to execute.

1: Power plant 10: Mill (crushing part)
11: Housing 12: Rotating table 13: Roller 14: Drive unit 16: Rotary classifier (classifier)
16a: Blade 17: Fuel supply unit 18: Motor 19: Outlet 20: Coal supply machine 21: Banker 22: Conveyance unit 23: Motor 24: Down spout unit 30: Blower unit 30a: Hot gas flow path 30b: Cold gas flow path 30c: Hot gas damper 30d: Cold gas damper 31: Primary air ventilator (PAF)
32: Push-in air ventilator (FDF)
34: Heat exchanger 40: State detection unit 41: Bottom surface 42: Ceiling 45: Journal head 47: Support arm 48: Support shaft 49: Pressing device 60: Control unit 62: Stop unit 63: Execution unit 64: First Stop unit 65: Second stop unit 71: Thermometer 72: Flow meter 100: Solid fuel crusher 100a: Transport gas flow path 100b: Supply flow path 110: CPU
120: ROM
130: RAM
140: HDD
150: Communication unit 180: Bus 200: Boiler 210: Fire furnace 220: Burner unit

Claims (12)

A stable operation control system applied to a solid fuel crushing device including a crushing unit for crushing solid fuel and a blower unit for supplying a transport gas to the crushing unit.
A stop unit that stops the operation of the crushing unit when the flow rate of the conveyed gas supplied to the crushing unit falls below a predetermined value.
When the temperature of the transport gas supplied to the crushing unit becomes equal to or higher than the threshold value, a temperature reduction mode for lowering the temperature of the transport gas is executed within a range in which the flow rate of the transport gas becomes equal to or higher than the predetermined value. Execution part and
Stable operation control system equipped with. The stable operation control system according to claim 1, wherein the execution unit controls the flow rates of the cold gas and the hot gas constituting the transport gas to execute the temperature reduction mode. The stable operation control system according to claim 2, wherein the execution unit reduces the flow rate of the hot gas in the temperature reduction mode. The stable operation control system according to claim 2, wherein the execution unit stops the supply of the hot gas and increases the flow rate of the cold gas in the temperature reduction mode. The stable operation control system according to claim 2, wherein the execution unit increases the flow rate of the cold gas in the temperature reduction mode. The stable operation control according to claim 1 or 2, wherein the execution unit can execute a plurality of the temperature reduction modes, and preferentially executes the temperature reduction mode having a low degree of influence on the flow rate reduction of the conveyed gas. system. The stop unit stops the operation of the crushed unit when the operating state of the boiler that burns using the crushed solid fuel becomes a preset unstable state during the temperature reduction mode. The stable operation control system according to any one of claims 1 to 6. The stable operation control system according to claim 7, wherein the operating state of the boiler is at least one of the exhaust gas properties of the boiler, the boiler main steam temperature, and the boiler main steam pressure. The stop unit is any of claims 1 to 8 for stopping the operation of the crushing unit when the temperature of the conveyed gas discharged from the crushing unit becomes equal to or lower than the dew point while the temperature reduction mode is being executed. The stable operation control system according to item 1. A crusher that crushes solid fuel,
A blower that supplies transport gas to the crushed part and
The stable operation control system according to any one of claims 1 to 9,
A solid fuel crusher equipped with. A stable operation control method applied to a solid fuel crushing device including a crushing unit for crushing solid fuel and a blower unit for supplying a transport gas to the crushing unit.
A step of stopping the operation of the crushing section when the flow rate of the conveyed gas supplied to the crushing section becomes less than a predetermined value.
When the temperature of the transport gas supplied to the crushing unit becomes equal to or higher than the threshold value, a temperature reduction mode for lowering the temperature of the transport gas is executed within a range in which the flow rate of the transport gas becomes equal to or higher than the predetermined value. And the process to do
Stable operation control method having. A stable operation control program applied to a solid fuel crushing device including a crushing unit for crushing solid fuel and a blower unit for supplying a transport gas to the crushing unit.
A process of stopping the operation of the crushing unit when the flow rate of the conveyed gas supplied to the crushing unit becomes less than a predetermined value.
When the temperature of the transport gas supplied to the crushing unit becomes equal to or higher than the threshold value, a temperature reduction mode for lowering the temperature of the transport gas is executed within a range in which the flow rate of the transport gas becomes equal to or higher than the predetermined value. Processing to do and
Stable operation control program to let the computer execute.

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