KR20200035046A - Crusher and operation method of grinder - Google Patents

Abstract

It is an object of the present invention to suppress rapid combustion by spraying an extinguishing agent when rapid combustion occurs in the case, even if the pressure in the case is at least any other operating state. A grinder 5 for pulverizing solid fuel into finely divided solid fuel includes a housing 41 constituting the outer shell of the grinder 5, pressure sensors 61A, 61B for detecting pressure in the housing 41, and a grinder In the normal operation state of (5), when the pressure detected by the pressure sensor 61A is equal to or greater than a predetermined first threshold value, the first extinguishing agent ejecting portion 60A for ejecting the extinguishing agent and the pulverizer 5 In the stop operation state, when the pressure detected by the pressure sensor 61B is equal to or higher than the second threshold value, which is a threshold value different from the first threshold value, a second extinguishing agent ejection unit 60B for ejecting the extinguishing agent is provided. have.

Description

Crusher and operation method of grinder

The present invention relates to a pulverizer equipped with a fire extinguishing facility and a method of operating the pulverizer.

Solid fuels such as coal and biomass used in thermal power generation facilities are pulverized into a fine powder with a grinder and supplied to a combustion device such as a boiler. The pulverizer pulverizes solid fuel, such as coal or biomass, which has been fed into the pulverization table from the coal feed tube by crushing it between the crushing table and the crushing roller, and conveys gas supplied from the outer periphery of the crushing table. The pulverized and finely pulverized fuel is divided by the classifier into smaller particle sizes and conveyed to the combustion device.

Biomass fuels are attracting attention as one of measures to reduce carbon dioxide emissions, such as boilers using fossil fuels. Biomass fuel is supplied to a pulverizer in a pellet form and pulverized, but for example, it is likely to cause rapid combustion because it is easy to ignite by static electricity, and there is a possibility of rapid combustion than coal (pulverized coal). When using fuel, it is necessary to strengthen safety management.

Patent Document 1 discloses that when a pressure equal to or higher than the normal pressure occurs inside the mill, a plurality of provided suppressors are operated and the pulverized coal supplying means, grinding means, and separating means are stopped.

In patent document 2, when the pressure difference between the pressure along the traveling direction of the shock wave generated by the rapid combustion and the direction perpendicular to the traveling direction is greater than or equal to a predetermined pressure, or the internal pressure of the pulverizer or the heat air duct becomes greater than or equal to the predetermined pressure, the pulverizer It is disclosed to stop.

Japanese Patent Publication No. 58-035239 Japanese Patent Publication No. 2002-143714

Although Patent Document 1 and Patent Document 2 disclose that the function of the pulverizer is stopped when the pressure in the pulverizer becomes equal to or higher than a predetermined pressure, solids inside the pulverizer when the pulverizer is stopped or when the stopper is transferred No ignition of fuel is described.

The grinder is not only different in pressure within the grinder depending on the operating state (for example, a normal operating state or an operation stop operation state), but also in any operating state, when solid fuel is present, the grinder There is a possibility that rapid combustion may occur due to ignition of solid fuel inside the interior of the gas. Therefore, even if rapid combustion is suppressed by detecting ignition of solid fuel only for a specific operation state, there is a fear that rapid combustion cannot be suppressed in other operation states.

The present invention has been made in view of such circumstances, and at least when the pressure in the crusher is in any other operating state, when rapid combustion occurs in the case, the operation of the crusher and the crusher capable of suppressing rapid combustion by spraying an extinguishing agent. It aims to provide a method.

In order to solve the above-mentioned problems, the following means are employed for the grinder of the present invention and the operating method of the grinder.

A pulverizer according to an aspect of the present invention is a pulverizer for pulverizing solid fuel into finely divided solid fuel, a case constituting the outer shell of the pulverizer, a pressure sensor for detecting pressure in the case, and the pulverizer In the first operating state, when the pressure detected by the pressure sensor is equal to or greater than a predetermined first threshold value, the first extinguishing agent ejecting unit for ejecting the extinguishing agent into the case and the pulverizer are different from the first operating state. A second extinguishing agent ejecting the extinguishing agent into the case when the pressure detected by the pressure sensor is equal to or greater than the second threshold value which is a threshold value different from the first threshold value in the second driving state in a different driving state. We have wealth.

Since there are many pulverized solid fuels in the case of the pulverizer, the pulverized fine solid fuel may ignite. When the finely divided solid fuel ignites, the pressure in the case rises above the pressure before rapid combustion (that is, the pressure during normal operation). For this reason, it is possible to determine the occurrence of rapid combustion by detecting the pressure in the case.

In the above-described configuration, another threshold value is set as a first threshold value in the first operation state and a second threshold value in the second operation state. Therefore, even when the pressure during normal operation is different in the first operation state and the second operation state, it is possible to determine the occurrence of rapid combustion in the case in each operation state. In addition, in the first driving state and the second driving state, another extinguishing agent ejection unit operates. In this way, even when the fire extinguishing agent is ejected in one driving state and the other driving state is achieved, the fire extinguishing agent can be ejected when rapid combustion occurs even in the other driving state. Therefore, even if the pressure in the case is at any other operating state, in the case where rapid combustion occurs in the case, the extinguishing agent can be ejected to suppress rapid combustion.

The pulverizer according to an aspect of the present invention, wherein the first operating state is the normal operating state of the pulverizer, and the second operating state is a stop operation state including when the grinder is stopped and when the operation is stopped. , The first threshold value may be set based on the highest pressure in the case in the normal operation state, and the second threshold value may be set based on the pressure in the case in the stop operation state. Further, the second threshold value may be set higher than the first threshold value.

In the above configuration, the first threshold value is set based on the pressure in the case in which the grinder is in the normal operating state. Thereby, the pulverizer is in the normal operating state, and in response to the rapid combustion occurring in the case, the extinguishing agent can be injected, and rapid combustion can be suppressed. Further, in the stop operation state, the pressure value in the case changes in each operation state, so the second threshold value is set based on the highest pressure in the case in which the grinder is in the stop operation state. As a result, the pulverizer is in a stationary operation state, and in response to the rapid combustion occurring in the case, the extinguishing agent can be injected to suppress rapid combustion.

Therefore, for example, when the rapid combustion occurs in the case in the normal operation state, and after the first extinguishing agent injection part injects the extinguishing agent to suppress the rapid combustion, in order to stop the pulverizer, it is operating in a stop operation state, Even when rapid combustion occurs in the case again, the rapid combustion in the case can be suppressed by the second extinguishing agent injection part spraying the extinguishing agent.

In addition, as a method of setting the first threshold value based on the pressure in the case in the normal operation state, for example, as the first threshold value, the pressure obtained by adding a predetermined pressure to the normal pressure in the normal operation state is applied. You may set. Moreover, as a method of setting the second threshold value based on the pressure in the case in the stationary operation state, for example, as the second threshold value, the pressure obtained by adding a predetermined pressure to the normal pressure in the stationary operation state is applied. You may set.

The pulverizer according to one aspect of the present invention may be provided in pairs of the first extinguishing agent ejecting portion and the second extinguishing agent ejecting portion.

In the above structure, the first extinguishing agent ejecting portion and the second extinguishing agent ejecting portion are provided in pairs. Thereby, when performing installation or maintenance of the 1st fire extinguishing agent spraying part and the 2nd fire extinguishing agent spraying part, it is possible to work simultaneously with respect to the 1st fire extinguishing agent spraying part and the 2nd fire extinguishing agent spraying part. Therefore, compared to the case where the first extinguishing agent ejecting portion and the second extinguishing agent ejecting portion are separately provided, it is possible to reduce the work load during installation and also reduce the work load during maintenance.

According to the type of the solid fuel, the pulverizer according to an aspect of the present invention may not spray the extinguishing agent from the first extinguishing agent ejecting portion and / or the second extinguishing agent ejecting portion.

In the above configuration, the extinguishing agent is not injected from the first extinguishing agent ejecting part and / or the second extinguishing agent ejecting part depending on the type of solid fuel pulverized by the grinder. Thereby, it is possible to determine whether or not to inject an extinguishing agent into the case according to the type of the solid fuel. Therefore, for example, when pulverizing a solid fuel having low ignition property, when the extinguishing agent is not ejected from the first extinguishing agent ejecting part and / or the second extinguishing agent ejecting part, rapid combustion does not occur in the case. In, the pressure rises due to factors other than rapid combustion, and a malfunction of spraying an extinguishing agent into the case can be prevented.

The grinder according to one aspect of the present invention includes a carrier gas supply pipe through which the carrier gas supplied into the case flows, and a part of the carrier gas supply pipe is opened by the inside of the carrier gas supply pipe becoming a predetermined pressure or more (開口).

In the said structure, a part of a conveyance gas supply pipe is opened because the inside of a conveyance gas supply pipe becomes a predetermined pressure or more. As a result, when rapid combustion occurs in the case and the pressure rise in the case propagates in the carrier gas supply pipe, a part of the carrier gas supply pipe is opened when the pressure in the carrier gas supply pipe exceeds a predetermined pressure. When a part of the conveying gas supply pipe is opened, the pressure is effectively released from the opening portion, so that a rise in excess of a predetermined pressure of the pressure in the conveying gas supply pipe can be suppressed. Therefore, while maintaining the pressure in the conveying gas supply pipe below a predetermined pressure, the rapid increase in pressure in the case of the grinder is also suppressed, and the increase in the density of local fine solid fuel in the case is suppressed to further suppress the progress of rapid combustion. have. Therefore, it is possible to prevent the carrier gas supply pipe from being damaged due to the pressure inside the carrier gas supply pipe being higher than expected, and to further suppress rapid combustion when the extinguishing agent in the case of the pulverizer is ejected.

In addition, since a part of the conveying gas supply pipe is opened, the pressure in the conveying gas supply pipe can be taken out without having to provide a new space for a device such as a disk by separately rupturing the carrier gas supply pipe. Therefore, compared with the case of providing a separate device or the like, space saving and cost reduction can be achieved.

A method of operating a grinder according to an aspect of the present invention is a method of operating a grinder for pulverizing solid fuel supplied in a case constituting an outer shell, a pressure detection step for detecting the pressure in the case, and the grinder operating first In the state, when the pressure detected in the pressure detection step is equal to or greater than a predetermined first threshold value, a first extinguishing agent ejecting step for ejecting the extinguishing agent from the first extinguishing agent ejecting portion in the case and the pulverizer In the second driving state, which is a different driving state from the first driving state, when the pressure detected in the pressure detection step is equal to or greater than the second threshold value, which is a threshold value different from the first threshold value, in the case, the second 2 A second extinguishing agent ejecting step for ejecting the extinguishing agent from the extinguishing agent ejecting portion is provided.

According to the present invention, even if the pressure in the case is at least any other operating state, in the case where rapid combustion occurs in the case, an extinguishing agent can be ejected to suppress rapid combustion.

1 is a schematic configuration diagram showing a boiler facility equipped with a grinder according to a first embodiment of the present invention.
2 is a longitudinal sectional view showing a grinder according to a first embodiment of the present invention.

Hereinafter, an embodiment of a pulverizer and a method of operating the pulverizer according to the present invention will be described with reference to the drawings.

[First Embodiment]

Hereinafter, 1st Embodiment of this invention is described using FIG. 1 and FIG.

1, the boiler installation 1 equipped with the grinder which concerns on this embodiment is shown. In addition, in this embodiment, the upper side represents the vertical upward direction, and the lower side represents the vertical downward direction.

In the present embodiment, the boiler facility 1 uses, for example, biomass fuel as a solid fuel, and a pulverizer for pulverizing solid fuel such as biomass fuel supplied to the boiler body 3 into finely divided solid fuel ( 5). The pulverizer 5 may be a type in which only biomass fuel is pulverized or a type in which biomass fuel is crushed together with coal. Here, the biomass fuel is an organic resource derived from renewable organisms, for example, thinning wood, waste wood, driftwood, grass, waste, mud, tires, and recycling using them as raw materials. It is a fuel (pellet or chip) and the like, and is not limited to what is presented here. Since biomass fuel is considered to be a carbon neutral that does not emit carbon dioxide, which is a global warming gas, in terms of introducing carbon dioxide in the growth process of biomass, its use has been studied in various ways.

A pulverized fuel supply pipe 7 is connected to the pulverizer 5, and the pulverized fuel pulverized by the pulverizer 5 is guided to the burner 9 through the pulverized fuel supply pipe 7 together with heat air serving as a carrier gas. .

In the pulverizer 5, biomass fuel stored in the biomass silo 11 is guided through the bunker 13.

A heat air supply pipe (carrying gas supply pipe) 15 is connected to the pulverizer 5. The hot air supply pipe 15 is connected to the primary ventilator 17, and air preheated by the air preheater 19 and air bypassing the air preheater 19 are mixed to induce temperature adjusted air. It is supposed to be. In addition, a portion of the exhaust gas that has passed through the electrostatic precipitator 23 is guided through the gas recirculation ventilator 21 to the heat air supply pipe 15. Therefore, a mixer in which the temperature is adjusted in the air preheater 19 and the oxygen concentration is adjusted by the exhaust gas is guided to the grinder 5 through the heat air supply pipe 15.

In the furnace in the boiler body 3, a flame is formed by the burner 9, and steam is generated by a heat exchanger (not shown) in the boiler body 3. The generated steam is guided to a steam turbine (not shown) to generate electricity.

The exhaust gas discharged from the boiler body 3 is denitrated by the denitrification device 25 and then heated in the air preheater 19 to the electrostatic precipitator 23 after heating the air derived from the primary ventilator 17. . After the exhaust gas is exhausted from the electrostatic precipitator 23, it is led to the desulfurization device 29 through the attracted ventilator 27. On the upstream side of the manned ventilator 27, some exhaust gas may be extracted and guided to the heat air supply pipe 15 through the gas recirculation ventilator 21.

The exhaust gas derived from the manned ventilator 27 is desulfurized in the desulfurization device 29 and then led to the chimney 31 and discharged to the atmosphere.

2, the details of the grinder 5 shown in FIG. 1 are shown. The grinder 5 is a vertical mill, and pulverizes solid fuel such as biomass fuel to make it fine.

The housing (case) 41 constituting the outer shell of the grinder 5 has a vertical cylindrical hollow shape, and a fuel supply pipe 43 is attached to the center of the ceiling 42. The fuel supply pipe 43 supplies pellet-like biomass fuel derived from the biomass silo 11 (see FIG. 1) into the housing 41, and vertically (vertical) to the center position of the housing 41. Direction), and the lower end is spoken to the inside of the housing 41.

A trestle 44 is installed on the bottom surface portion 40 of the housing 41, and a crushing table 45 is rotatably arranged on the trestle 44. The lower end of the fuel supply pipe 43 is arranged to face the center of the grinding table 45. The fuel supply pipe 43 supplies biomass fuel from the top to the bottom, as indicated by the arrow A0.

The crushing table 45 is rotatable around a central axis in the vertical direction (vertical direction), and is driven by a driving device (not shown). The upper surface of the crushing table 45 may have, for example, a high center, an inclined shape that decreases toward the outside, and an outer circumferential portion may be curved upward.

Above the crushing table 45, a plurality of crushing rollers 46 are arranged to face each other. Each crushing roller 46 is arranged at equal intervals in the circumferential direction above the outer circumferential portion of the crushing table 45 (also, only one crushing roller 46 and its peripheral devices are shown representatively in FIG. 2). ). The crushing roller 46 is capable of swinging up and down, and is supported so as to be accessible from and to the upper surface of the crushing table 45. When the grinding table 45 rotates while the outer circumferential surface is in contact with the upper surface of the grinding table 45, the grinding roller 46 receives rotational force from the grinding table 45 and rotates together. When biomass fuel is supplied from the fuel supply pipe 43, the biomass fuel is compressed between the grinding roller 46 and the grinding table 45 and crushed.

A scraper 48 for vertically discharging the crushing table 45 to discharge biomass fuel or foreign substances deposited on the bottom surface portion 40 of the housing 41 to the outside of the housing 41 is provided. The scraper 48 is fixed to a part of the crushing table 45 and is rotatable coaxially with the crushing table 45. At the distal end of the scraper 48, a brush portion 49 is provided. The brush portion 49 is arranged such that the lower end is in contact with the upper surface of the bottom surface portion 40 of the housing 41, and the upper surface of the bottom surface portion 40 is slid. Moreover, it is the bottom surface part 40 of the housing 41, and the discharge opening 50 is formed on the rotational orbit of the brush part 49. The discharge opening 50 communicates with the pyrite box 52 disposed outside the housing 41 through the discharge pipe 51.

A heat air supply pipe 15 (see FIG. 1) is connected to the lower portion of the housing 41. The heat air supply pipe 15 includes a preheating air flow pipe 15b through which air preheated by the air preheater 19 flows, and a cooling air flow pipe 15c through which cooling air bypassing the air preheater 19 flows, Preheated air circulating in the preheating air distribution pipe 15b and cooling air circulating in the cooling air distribution pipe 15c join (mix) the confluence section 15a and the mixed air in the confluence section 15a. It has a mixed air flow pipe 15d. The mixed air flow pipe 15d is in communication with the housing 41. The air is supplied from the primary ventilator 17, of which preheated air heated by the air preheater 19 and cold air supplied by bypassing the air preheater 19 are supplied, and preheated air and cold air are joined. In (15a), the heat air is controlled to reach a temperature in a predetermined range. In addition, a part of the exhaust gas that has passed through the electrostatic precipitator 23 is induced through the gas recirculation ventilator 21, and the oxygen concentration of the heat air is adjusted by the exhaust gas.

A part of the cooling air flow pipe 15c is formed of, for example, a flexible expansion 47 so as to allow expansion and contraction of the cooling air flow pipe 15c in the extending direction. In addition, the expansion 47 is formed so that it breaks (opens) when the pressure inside the heat air supply pipe 15 reaches a predetermined pressure. The predetermined pressure at which the expansion 47 breaks is set based on the pressure in the housing 41 in the normal operating state. Specifically, the pressure is higher than the pressure acting on the expansion 47 during normal operation of the grinder 5 (that is, a situation in which no abnormality such as rapid combustion occurs), and heat air supplied to the heat air supply pipe 15 The various devices (for example, the primary ventilator 17 or the air preheater 19) disposed on the upstream side of the flow of are set to a pressure lower than the pressure at which they are broken. In addition, in this embodiment, although the expansion 47 is broken, it is not limited to this, You may be formed so that a part of a flange seam part or another exchangeable part, such as a measurement sheet, may be broken (opened).

The hot air supplied by the hot air supply pipe 15 is guided into the housing 41 as indicated by the arrow A1, and is supplied to the lower space S1 located below the grinding table 45.

2, the piping through which the exhaust gas flows from the gas recirculation ventilator 21 is omitted for illustration.

A space in which ignition and rapid combustion may occur will be described. In this embodiment, the lower space S1, the upper space S2, and the classification space S3 correspond.

The side wall portion of the housing 41 forming the lower space S1 is provided with an extinguishing agent ejection device 60 for spraying the extinguishing agent into the lower space S1. The extinguishing agent ejecting device 60 includes a first extinguishing agent ejecting portion 60A and a second extinguishing agent ejecting portion 60B. The first extinguishing agent ejecting portion 60A and the second extinguishing agent ejecting portion 60B are provided in pairs. That is, the first extinguishing agent ejecting portion 60A and the second extinguishing agent ejecting portion 60B are provided close to each other. Moreover, you may arrange | position the 1st fire extinguishing agent blowing part 60A and the 2nd fire extinguishing agent blowing part 60B.

In the present embodiment shown in Fig. 2, two extinguishing agent ejection devices 60 are provided in the lower space S1, for example, two each of the first extinguishing agent ejection unit 60A and the second extinguishing agent ejection unit 60B. ), And is provided to face the center axis of the housing 41 therebetween. However, the number of the extinguishing agent ejection devices 60 is not limited to two, and is determined according to the size of the lower space S1.

In the lower space S1, the pressure sensor 61 may be provided at a position indicated by an X mark. The pressure sensor 61 has a first pressure sensor 61A and a second pressure sensor 61B, and the first pressure sensor 61A and the second pressure sensor 61B are provided in pairs. That is, the first pressure sensor 61A and the second pressure sensor 61B are provided close to each other. Moreover, you may arrange | position the 1st pressure sensor 61A and the 2nd pressure sensor 61B apart.

In addition, the pressure sensor 61 in the lower space S1 may be omitted (to be described later).

On the upper part of the housing 41, a rotary separator (classifier) 53 is provided. The rotary separator 53 is disposed to surround the fuel supply pipe 43 and rotates around the fuel supply pipe 43. With the rotation of the rotary separator 53, a plurality of blades 53a mounted on the outer circumferential side are made to travel in the circumferential direction. The fine powder of the biomass fuel pulverized by the crushing table 45 and the crushing roller 46 flows from the lower space S1 through the outer circumferential side of the crushing table 45 (arrow (A2)). (See above). Among the finely pulverized powder, the fine powder having a relatively large diameter is shaken off by the blade 53a, returned to the crushing table 45, and pulverized again. Thereby, the rotary separator 53 is classified to the size of the fine powder, and the fine powder of the biomass fuel having a predetermined diameter or less is transported and discharged from the fine fuel supply pipe 7 together with the heat air.

An upper space S2 is formed between the upstream side of the rotary separator 53 (the lower side of the rotary separator 53) and the upper side of the grinding table 45. On the side wall portion of the housing 41 forming the upper space S2, a fire extinguishing agent ejection device 60 for spraying the fire extinguishing agent toward the upper space S2 is provided. In FIG. 2, two extinguishing agent ejection devices 60 are provided in the upper space S2, for example, and are provided so as to face each other with the central axis of the housing 41 interposed therebetween. The number of extinguishing agent ejection devices 60 is not limited to two. However, the number of the fire extinguishing agent ejection device 60 is determined according to the size of the upper space S2.

When two extinguishing agent ejection devices 60 are provided, for example, the center axis of the housing 41 is provided so as to face each other, but the extinguishing agent ejection device 60 of the upper space S2 and the lower space The extinguishing agent ejection device 60 of (S1) need not be at the same position in the circumferential direction of the housing 41, but may be shifted in the circumferential direction of each other. For this reason, it is possible to spray the extinguishing agent by reducing the deflection over a wide area in both of the upper space S2 and the lower space S1.

In the upper space S2, a pressure sensor 61 for detecting rapid combustion is provided at a position indicated by an X mark. The number of the pressure sensors 61 is determined according to the volume in the upper space S2, and in the present embodiment shown in Fig. 2, for example, two. The number of pressure sensors 61 is not limited to two.

A fine fuel supply pipe 7 is connected to the ceiling portion 42. The fine fuel supply pipe 7 discharges the fine powder of the biomass fuel after being classified by the rotary separator 53 together with the heat air as indicated by the arrow A3, and guides it to the boiler body 3 (see FIG. 1). do. A classification space S3 is formed in the space on the downstream side of the rotary separator 53 and on the upstream side of the fine fuel supply pipe 7 (that is, the inner space surrounded by the blades 53a of the rotary separator 53). It is done.

The ceiling part 42 forming the classification space S3 is provided with an extinguishing agent ejection device 60 for spraying the extinguishing agent toward the interior of the classification space S3. In FIG. 2, the extinguishing agent ejection device 60 provided in the classification space S3 is, for example, one. The number of extinguishing agent ejection devices 60 is not limited to one. However, the number of fire extinguishing agent ejection devices 60 is determined according to the size of the classification space S3.

In the classification space S3, a pressure sensor 61 for detecting rapid combustion is provided at a position indicated by an X mark. The number of pressure sensors 61 provided in the classification space S3 is determined according to the volume in the classification space S3, and in the present embodiment shown in FIG. 2, for example, one. The number of pressure sensors 61 is not limited to one.

Fire extinguishing agent ejected from the extinguishing agent ejection device 60 provided in the lower space S1, the upper space S2 and the classification space S3 (that is, from the first extinguishing agent ejecting portion 60A and the second extinguishing agent ejecting portion 60B) As a fire extinguishing agent), regardless of the type, provided with a fire extinguishing function, for example, powder (sodium hydrogen carbonate: generally sodium bicarbonate) is used.

The pressure sensor 61 provided in the lower space S1, the upper space S2, and the classification space S3 detects a pressure increase when the biomass fuel is ignited in the pulverizer 5 and rapid combustion occurs. . The output of the pressure sensor 61 is transmitted to the control part (not shown). The control unit determines the occurrence of rapid combustion from the pressure value transmitted from the pressure sensor 61, and based on the result, the fire extinguishing agent ejection device provided in the lower space S1, the upper space S2, and the classification space S3 ( 60).

Specifically, as shown below, the control unit determines the occurrence of rapid combustion, and controls the operation of the extinguishing agent ejection device 60.

The control unit always grasps the operating state of the grinder 5. The operating state of the grinder 5 may be automatically determined by the control unit or may be manually input.

When the operating state of the grinder 5 is in a normal operating state (first operating state), the control unit rapidly burns when the pressure detected by the first pressure sensor 61A exceeds a predetermined first threshold value. I think it happened. When it is determined that rapid combustion has occurred by the control unit in the normal operation state, the fire extinguishing agent is controlled to be ejected from the first extinguishing agent ejecting portion 60A almost simultaneously with this.

In addition, the control unit is rapid even when the pressure detected by the second pressure sensor 61B exceeds a predetermined second threshold value when the operating state of the grinder 5 is in a stopped operating state (second operating state). It is determined that combustion has occurred. When it is determined that rapid combustion has occurred by the control unit in the stop operation state, the fire extinguishing agent is controlled to be ejected from the second extinguishing agent ejecting portion 60B almost simultaneously with this.

In addition, the normal operating state means an operating state in which the biomass fuel is pulverized into a fine powder in the grinder 5 and the fine powder of the crushed biomass fuel is supplied to the boiler body 3 by heat air for conveying. . In addition, the stop operation state means an operation state including both the state in which the grinder 5 is stopped (when the operation is stopped) and the state where the operation is stopped (when the operation is stopped). In the state of moving to the stoppage, in order to stop the operation, the rotary separator 53 is rotated at a high speed to clean the rotary separator 53, and the biomass fuel and heat air are supplied into the housing 41. There is a clearing state in which the biomass fuel is discharged from the pulverizer 5 by rotating the crushing table 45 and the scraper 48 in a non-existing state.

In addition, the generation of rapid combustion by the control unit may be determined as follows. The control unit determines that rapid combustion has occurred when any one pressure sensor 61 provided in the lower space S1, the upper space S2, and the classification space S3 detects a pressure exceeding a predetermined threshold value. do. Or, in the normal operation state, the first pressure of the two first pressure sensors 61A among the pressure sensors 61 provided in the upper space S2 and the pressure sensor 61 provided in the classification space S3. When two of the three first pressure sensors 61A composed of the sensors 61A detect a pressure exceeding a predetermined threshold, it may be judged as the occurrence of rapid combustion and suppress the misjudgment. In addition, the control unit similarly, in the stop operation state, the second pressure sensor 61B of the two pressure sensors 61 provided in the upper space S2 and the pressure sensor 61 provided in the classification space S3 are 1 When two of the three second pressure sensors 61B composed of the two second pressure sensors 61B detect a pressure exceeding a predetermined threshold, it may be judged as the occurrence of rapid combustion to suppress misjudgment. . When it is determined that the rapid combustion has occurred by the control unit, the fire extinguishing agent is controlled to be ejected from the extinguishing agent ejection device 60 provided in the lower space S1, the upper space S2, and the classification space S3 almost simultaneously with this.

The first threshold value is set based on the pressure in the housing 41 in the normal operating state. Specifically, it is set in a normal operating state, and is set to a pressure in which a predetermined pressure (for example, 200 Aq or more and 500 Aq or less) is added to the pressure in the housing 41 when operating normally. Moreover, the 2nd threshold value is set based on the highest pressure in the housing 41 in a stop operation state. Specifically, it is in the stop operation state, and since the pressure value varies according to each operation state, the highest pressure in the housing 41 when operating normally is a predetermined pressure (for example, 200 Aq or more and 500 Aq or less) Is set to the pressure added. In addition, since the pressure in the housing during normal operation and during normal operation and the pressure in the housing 41 during normal operation during stop operation are different pressure values, they are the first and second threshold values. The value of 곗 becomes a different pressure. Specifically, in the stationary operation state, the inert gas is supplied into the housing 41 in a large amount in the clearing state in which the biomass fuel is discharged from the grinder 5, and the pressure is higher than in normal operation. That is, in the stop operation state, an operation of introducing an inert gas for the purpose of lowering the oxygen concentration in the housing 41 occurs, and the internal pressure of the housing 41 increases by the amount of input of the medium. In addition, the second threshold value is set higher than the first threshold value.

The control unit includes, for example, a central processing unit (CPU), random access memory (RAM), read only memory (ROM), and a computer-readable storage medium. In addition, a series of processes for realizing various functions are stored in a storage medium or the like in the form of a program as an example, and various functions are performed by reading the program into a RAM or the like and performing processing and computation processing of information. Is realized. Further, the program may be applied in a form previously installed in a ROM or other storage medium, a form provided in a state stored in a computer-readable storage medium, or a form transmitted through communication means by wire or wireless. do. Computer-readable storage media are magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

The reason for installing the extinguishing agent ejection device 60 in the lower space S1, the upper space S2, and the classification space S3 will be described.

The reason for installing the extinguishing agent ejection device 60 in the upper space S2 and the classification space S3 is that in the upper space S2, a large amount of biomass fuel after pulverization exists for the upper portion of the grinding table 45. This is because in the classification space S3, when there is a large amount of biomass fuel that has been finely divided, and when the heat air serving as the carrier gas is heated, it is easier to ignite than other spaces. Furthermore, there is a spark generated due to the case where volatile matter or foreign matter is mixed from the biomass fuel, and it is a space that is easily ignited compared to other spaces. Therefore, the pressure sensor 61 is also provided in such a space so that fire extinguishing can be performed at an appropriate timing.

On the other hand, the lower space (S1) is the lower side of the grinding table 45, and the biomass fuel pulverized on the grinding table 45 is blown up by the heat air supplied to the lower space (S1), so the upper space ( Compared to S2), the amount of fine powder is small. However, there are many fine powders of biomass fuel, and since there is a large amount of heat air, there is a fear of ignition compared to other spaces. Therefore, the extinguishing agent ejection device 60 is provided. However, the pressure sensor 61 may be omitted, or the signal of the pressure sensor 61 in the upper space S2 or the classification space S3 close to the lower space S1 may be used.

As described above, hot air is supplied from the heat air supply pipe 15 to the lower space S1, passes through the upper space S2, passes through the classification space S3, and flows to the fine fuel supply pipe 7. The fuel pulverized between the pulverizing roller 46 and the pulverizing table 45 becomes a fine powder, is entangled by hot air, and classified after passing through the rotary separator 53, and then passes through the fine fuel supply pipe 7 to the boiler body ( It is guided to the burner 9 of 3). For this reason, there are spaces having the effect of rapid combustion in addition to the lower space S1, the upper space S2, and the classification space S3.

Next, unlike a space in which ignition and rapid combustion occur, a space in which ignition of rapid combustion may occur due to ignition in another space will be described. In this embodiment, the fuel supply pipe 43, the heat air supply pipe 15, and the fine fuel supply pipe 7 correspond.

The fire extinguishing agent blowing device 60 is also provided in the fuel supply pipe 43, the heat air supply pipe 15, and the fine fuel supply pipe 7. The fire extinguishing agent ejection device 60 provided in the heat air supply pipe 15 is provided on the downstream side of the flow of heat air rather than the confluence section 15a. Each extinguishing agent ejection device 60 is controlled by a control unit in the same manner as the above-described extinguishing agent ejection device 60. By these extinguishing agent blowing devices 60, the spread of rapid combustion is prevented.

In addition, when the expansion 47 which ruptures at a predetermined pressure is provided in a part of the cooling air flow pipe 15c, the expansion 47 ruptures, so that the heat air supply pipe 15 does not reach a predetermined pressure or higher. In the case of a space having a capacity to suppress the spread of rapid combustion, the extinguishing agent ejection device 60 provided in the heat air supply pipe 15 may be omitted in some cases.

In addition, the fuel supply pipe 43, the heat air supply pipe 15, and the fine fuel supply pipe 7 may need to be provided with an extinguishing agent ejection device 60 because there is a risk of smearing, but the possibility of ignition is low, so the pressure sensor ( It is not necessary to provide 61), and by using the signal of the pressure sensor 61 in the upper space S2 or the classification space S3 close to the blurring space, an appropriate timing of the extinguishing agent is taken into account in consideration of the propagation time of rapid combustion. It is desirable to be ejected to.

The installation position of the extinguishing agent ejection device 60 is provided in consideration of the propagation time of rapid combustion. Specifically, in the case where rapid combustion occurs, it is provided at a position where the extinguishing agent can be sprayed before and after the flame propagation of the rapid combustion reaches. Pressure increase can be suppressed by spraying an extinguishing agent before and after the smear propagation reaches.

On the other hand, when the installation position of the fire extinguishing agent blowing device 60 is closer to the place where rapid combustion occurs than the appropriate position, since the fire extinguishing agent is too fast against the expansion of the flame, the fire extinguishing agent does not develop due to the spread by spreading the flame. After passing through the device 60, the fire extinguishing agent is sprayed, and the spread of smear cannot be effectively suppressed. After spraying the fire extinguishing agent, a flame develops and spreads, and the pressure rises.

In addition, when the installation position of the fire extinguishing agent ejection device 60 is farther from the location where rapid combustion occurs than the appropriate position, the fire extinguishing agent is ejected after the spread of the spread of the spread, the digestion is slow, or the spread of the spread of the spread is greater than that of the design It is necessary to add an extinguishing agent in a state, and a large amount of extinguishing agent is required more than the expected amount of extinguishing agent, and rapid combustion cannot be effectively suppressed. This causes a cost increase.

The grinder 5 of the above structure operates as follows.

When biomass fuel is input from the fuel supply pipe 43 toward the center of the grinding table 45 (see arrow A0), the biomass fuel is crushed by the centrifugal force by rotation of the grinding table 45. It is guided to the outer circumferential side of, and is crushed by entering between the crushing rollers 46. The pulverized biomass fuel is wound upward by hot air derived from the heat air supply pipe 15 (see arrow A2), and is guided to the rotary separator 53. In the rotary separator 53, the fine powder with a relatively large diameter is shaken off by the blade 53a and returned to the grinding table 45. The fine powder after classification that has passed through the blade 53a is guided to the fine powder fuel supply pipe 7 together with the hot air, and supplied to the burner 9 (see FIG. 1) of the boiler body 3.

When the biomass fuel is ignited during the normal operation of the grinder 5 as described above, and rapid combustion occurs, the control unit generates rapid combustion by the detection value of the first pressure sensor 61A properly provided in each space. It is judged, and the fire extinguishing agent is sprayed at the appropriate timing from each of the first fire extinguishing agent ejecting portions 60A provided in each space. In the case where the biomass fuel is ignited during the stationary operation of the grinder 5 and rapid combustion occurs, the control unit generates rapid combustion by the detection value of the second pressure sensor 61B properly provided in each space. Judging, the fire extinguishing agent is sprayed at an appropriate timing from each of the second fire extinguishing agent ejecting portions 60B appropriately provided in each space.

Specifically, the control unit performs the following control.

First, the control unit determines the operating state of the grinder 5. When the operation state is the normal operation state, the first pressure sensor 61A detects the pressure in the housing 41 (pressure detection step), and transmits the detected pressure to the control unit. The control unit determines whether the pressure detected by the first pressure sensor 61A is equal to or greater than the first threshold value. When it is equal to or higher than the first threshold, it is determined that biomass fuel is ignited in the pulverizer 5 and rapid combustion has occurred, and the extinguishing agent is ejected from each of the first extinguishing agent ejection units 60A (first extinguishing agent ejection step). When the detected pressure is lower than the first threshold value, the operation returns to the step of determining the operating state. Moreover, after extinguishing an extinguishing agent, it returns to the step of determining a driving condition. Moreover, when cleaning the extinguishing agent ejected from each 1st fire extinguishing agent ejection part 60A, it shifts to the operation | movement which stops the grinder 5.

On the other hand, when the operation state is the stop operation state, the second pressure sensor 61B detects the pressure in the housing 41 (pressure detection step), and transmits the detected pressure to the control unit. The control unit determines whether the pressure detected by the second pressure sensor 61B is equal to or greater than the second threshold value. When it is equal to or higher than the second threshold value, biomass fuel is ignited in the grinder 5, and it is determined that rapid combustion has occurred, and the extinguishing agent is ejected from each of the second extinguishing agent ejection units 60B (second extinguishing agent ejection step). When the detected pressure is lower than the second threshold value, the process returns to the step of determining the operating state. Moreover, when cleaning the fire extinguishing agent ejected from each 2nd fire extinguishing agent ejection part 60B, it shifts to the operation | movement which stops the grinder 5 completely.

According to this embodiment, the following operational effects are exhibited.

In the pulverizer 5, rapid combustion may occur even in a normal operating state or a stopped operating state.

In this embodiment, different threshold values are set in the normal operation state and the stop operation state. Specifically, the grinder 5 sets the first threshold value based on the pressure in the housing 41 in the normal operation state, and the grinder 5 is second based on the pressure in the housing 41 in the stationary operation state. The threshold is being set. In the normal operation state and the stop operation state, the pressure value during normal operation is different, but by setting the threshold value according to each operation state in this way, rapid combustion in the housing 41 is generated in any operation state. I can judge.

In addition, in the normal operation state and the stop operation state, another extinguishing agent ejection unit operates. Therefore, even in any operation state, since an extinguishing agent is prepared for each operation state, when rapid combustion occurs in the housing 41, the extinguishing agent can be ejected to suppress rapid combustion.

Therefore, for example, in the normal operation state, rapid combustion occurs in the grinder 5, and after the first extinguishing agent ejection portion 60A sprays the extinguishing agent to suppress the rapid combustion, to stop the grinder 5 , Even when the rapid combustion occurs in the grinder 5 again when operating in the stationary operation state, the second pressure sensor 61B and the control unit detect the rapid combustion, and the second extinguishing agent ejection unit 60B is the extinguishing agent By spraying, it is possible to suppress rapid combustion generated in the grinder 5.

In addition, the first extinguishing agent ejecting portion 60A and the second extinguishing agent ejecting portion 60B are provided in pairs. Thus, when the installation or maintenance of the first extinguishing agent ejecting portion 60A and the second extinguishing agent ejecting portion 60B is performed, for the installation work of the first extinguishing agent ejecting portion 60A and the second extinguishing agent ejecting portion 60B, You can work at the same time. Therefore, as compared with the case where the first extinguishing agent ejecting portion 60A and the second extinguishing agent ejecting portion 60B are respectively provided, it is possible to reduce the work load during installation and also reduce the work load during maintenance.

Moreover, the expansion 47 provided in a part of the heat air supply pipe 15 is broken by a predetermined pressure acting from the inside. As a result, when rapid combustion occurs in the grinder 5 and the pressure rise in the housing 41 propagates in the heat air supply pipe 15, when the pressure in the heat air supply pipe 15 reaches a predetermined pressure, the expansion 47 ) Is broken. When the expansion 47 breaks, the pressure is released from the breakage portion, so that the increase in pressure in the heat air supply pipe 15 can be suppressed. Therefore, the pressure in the heat air supply pipe 15 can be maintained below a predetermined pressure. Therefore, it is possible to prevent the heat air supply pipe 15 from being damaged beyond the portion of the expansion 47 due to the pressure inside the heat air supply pipe 15 being greater than or equal to the assumed pressure. In addition, it is possible to prevent various devices on the upstream side of the flow of the hot air supplied by the hot air supply pipe 15 from being damaged by propagation of pressure. In addition, since the breakage point of the heat air supply pipe 15 is set as an easily replaceable expansion 47, the breakage portion can be easily repaired.

In addition, by maintaining the pressure in the heat air supply pipe 15 below a predetermined pressure, the pressure in the case of the pulverizer 5 is also suppressed, and the density in which the fine powder of the biomass fuel is present increases locally. It is possible to suppress, further suppress the progress of rapid combustion in the housing 41 when the extinguishing agent is ejected, and more effectively suppress the rapid combustion when the extinguishing agent in the grinder 5 is ejected.

In addition, since the expansion 47 already installed in a part of the heat air supply pipe 15 is to be broken, an apparatus such as a rupture disk for suppressing pressure rise is not provided in the heat air supply pipe 15 separately. The pressure in the heat air supply pipe 15 can be withdrawn. In addition, when a separate device or the like is provided for the existing grinder 5, there is a possibility that the layout of the piping needs to be changed since it is necessary to secure a new space for disposing the device. If it is a structure, an increase in pressure can be suppressed without changing the layout of the conventional piping. Therefore, compared with the case of providing a separate device or the like, space saving and cost reduction can be achieved.

Further, in the present embodiment, an example of crushing biomass fuel as a solid fuel pulverized by the grinder 5 has been described, but the pulverized solid fuel is not limited to biomass fuel, and may be ignited coal or the like. . In addition, the pulverizer 5 may be a type in which only coal is pulverized or a type in which only biomass fuel is crushed. Further, the biomass fuel may be pulverized together with coal, or the coal and biomass fuel may be converted and pulverized.

In this embodiment, in the example in which the first pressure sensor 61A and the second pressure sensor 61B are respectively provided, and the pressure sensor for detecting the pressure is separately used according to the operating state of the grinder 5. Although the description has been made, one pressure sensor may be used, and the pressure may be detected by one pressure sensor in all operating states.

[Second Embodiment]

Hereinafter, the second embodiment of the present invention will be described.

In this embodiment, the pulverizer 5 is different from the first embodiment in that it is a type in which coal and biomass fuel are converted and crushed. About the other structure, since it is the same as 1st Embodiment, the description is abbreviate | omitted.

In the present embodiment, when pulverizing coal, which is a solid fuel with low ignition property, the pressure sensor 61 is stopped. On the other hand, when crushing biomass fuel, which is a solid fuel with high ignition property, the extinguishing agent ejection device 60, the pressure sensor 61, and the like are operated by the method described in the first embodiment. In this way, depending on the type of solid fuel pulverized by the grinder 5, the first extinguishing agent ejecting portion 60A and the second extinguishing agent ejecting portion 60B are not to be injected, to be injected, or to be switched. .

In addition, the stop of the pressure sensor 61 and switching of operation may be performed manually by an operator, or may be performed automatically by the control unit.

According to this embodiment, the following operational effects are exhibited.

Since the control unit determines the rapid combustion based on the pressure rise in the grinder 5, when the pressure rise due to other factors occurs despite the fact that the rapid combustion does not occur, the rapid combustion does not actually occur. It is possible to misjudge that rapid combustion has occurred. If such a wrong judgment is made, unnecessary extinguishing agent injection (malfunction) is performed. In this embodiment, when pulverizing coal, which is a solid fuel having low ignition property (that is, there is little possibility of rapid combustion), the extinguishing agent is injected from the first extinguishing agent ejecting portion 60A and the second extinguishing agent ejecting portion 60B. Not to do it. Therefore, even when the pressure rises due to factors other than rapid combustion in a state in which rapid combustion is not occurring, a malfunction of spraying an extinguishing agent into the grinder 5 can be prevented.

In addition, when pulverizing coal, which is a solid fuel with low ignition property, the first threshold value and the second threshold value are set when the biomass, which is a fuel with higher ignition property than coal, is used as solid fuel. And a value higher than the second threshold (for example, 2000 Aq or more). When the biomass fuel, which is a solid fuel having high ignition property, is crushed, the first threshold value and the second threshold value are set as described in the first embodiment. In this way, the first threshold value and the second threshold value are adjusted according to the type of solid fuel. In addition, the operator may manually adjust the first threshold value and the second threshold value, or the controller may automatically perform the adjustment.

In this way, when pulverizing coal, the pressure that does not actually reach is set as the threshold value, so that the fire extinguishing agent ejection device 60 can be brought into an inoperable state. Therefore, even when the pressure rises due to factors other than rapid combustion in a state where rapid combustion is not occurring, a malfunction that injects an extinguishing agent into the grinder 5 can be prevented.

In addition, this invention is not limited to the invention which concerns on each said embodiment, The deformation | transformation can be suitably carried out in the range which does not deviate from the summary. For example, in each of the above embodiments, the fuel supply pipe 43, the heat air supply pipe 15, and the fine fuel supply pipe 7 are provided with an extinguishing agent ejection device 60, but any one or two of them The fire extinguishing agent blowing device 60 may be provided in the.

1 Boiler equipment
3 Boiler body
5 grinder
7 Differential fuel supply pipe
9 burner
11 Biomass Silos
13 bunker
15 Heat air supply pipe (return gas supply pipe)
15b preheat air distribution pipe
15c cooling air flow pipe
15d mixed air distribution pipe
17 Primary ventilator
19 air preheater
21 gas recirculation ventilator
23 Electrostatic precipitator
25 Denitrification device
27 Manned Ventilator
29 Desulfurization device
31 chimney
40 bottom
41 Housing (case)
42 Ceiling
43 Fuel supply pipe
44 trestle
45 grinding table
46 grinding roller
47 expansion
48 scraper
52 Pyrite Box
60 fire extinguishing device
60A first extinguishing agent spray
60B second extinguishing agent spray
61 pressure sensor
61A first pressure sensor
61B 2nd pressure sensor

Claims (7)

A pulverizer for pulverizing solid fuel into finely divided solid fuel,
A case constituting the outer shell of the pulverizer,
And a pressure sensor for detecting the pressure in the case,
A first extinguishing agent ejection unit for ejecting an extinguishing agent into the case when the pressure detected by the pressure sensor is equal to or greater than a predetermined first threshold in the first operating state;
In a second operation state in which the grinder is in a different operation state from the first operation state, when the pressure detected by the pressure sensor is equal to or greater than a second threshold value that is a threshold value different from the first threshold value, the A pulverizer having a second extinguishing agent ejecting portion for ejecting an extinguishing agent in the case. The method according to claim 1,
In the first operation state, the grinder is in a normal operation state,
The second operation state is a stop operation state including when the grinder is stopped and when the stop is performed,
The first threshold value is set based on the pressure in the case in the normal operation state,
The second threshold value is set based on the highest pressure in the case in the stop operation state. The method according to claim 2,
The second threshold value is set higher than the first threshold value. The method according to any one of claims 1 to 3,
The first extinguishing agent ejecting portion and the second extinguishing agent ejecting portion are pulverizers provided in pairs. The method according to any one of claims 1 to 4,
According to the type of the solid fuel, the first extinguishing agent ejection unit and / or, the second extinguishing agent ejector from the extinguishing agent so as not to inject the pulverizer. The method according to any one of claims 1 to 5,
A carrier gas supply pipe through which the carrier gas supplied in the case flows is provided,
A part of the carrier gas supply pipe is a pulverizer that is opened by the inside of the carrier gas supply pipe being at a predetermined pressure or higher. As a driving method of the pulverizer to crush the solid fuel supplied in the case constituting the outer shell,
A pressure detection step for detecting pressure in the case,
A first extinguishing agent ejecting step for ejecting the extinguishing agent from the first extinguishing agent ejecting portion in the case when the pressure detected in the pressure detecting step is equal to or greater than a predetermined first threshold in the first operating state; ,
In a second operation state in which the grinder is in a different operation state from the first operation state, when the pressure detected in the pressure detection step is equal to or greater than a second threshold value that is a threshold value different from the first threshold value, A method of operating a pulverizer having a second extinguishing agent ejecting step for ejecting an extinguishing agent from the second extinguishing agent ejecting part in the case.

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