JP2013181680A - Solid fuel crushing device, and method for operation of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid fuel crushing device capable of preventing such a problem that a classified and pulverized fuel is deposited in a supply flow path for supplying the pulverized fuel to a burner unit, and to provide a method for operation of the same.SOLUTION: A solid fuel crushing device 1 includes: a primary air fan 90 for ventilating a primary air to supply coal pulverized by a roller to a classification unit; an air preheater 40 for preheating the primary air; a supply flow path for supplying a pulverized coal classified by the classification unit to a burner unit 110 for combusting the pulverized coal along with the primary air preheated by the air preheater 40; and a bypass flow path 104 for bypassing the primary air preheated by the air preheater 40 without passing a coal pulverization unit 10.

Description

  The present invention relates to a solid fuel crusher and a method for operating the solid fuel crusher.

Conventionally, a solid fuel pulverization apparatus that pulverizes solid fuel such as coal, classifies the pulverized solid fuel into a pulverized fuel smaller than a predetermined particle size, and supplies the classified pulverized fuel to a burner unit that burns the pulverized fuel Is known (for example, see Patent Document 1).
The conventional solid fuel pulverization apparatus supplies an oxidizing gas such as air containing an oxidant to a pulverization unit that pulverizes solid fuel such as coal, and raises the pulverized solid fuel. To produce an oxidizing gas mixed with the finely divided fuel, and supply the oxidizing gas mixed with the finely divided fuel to the burner section.

JP 2001-29835 A

  When solid fuel such as coal containing a large amount of water is pulverized by a fuel pulverizer, the humidity in the supply flow path for supplying finely pulverized fuel from the fuel pulverization unit to the burner unit increases. When the humidity is high, moisture is condensed in the supply channel, and the pulverized fuel is easily deposited on the supply channel. When the pulverized fuel is deposited on the supply flow path, there is a problem that the flow path diameter of the supply flow path is reduced due to the deposit or a problem that the deposit generates heat.

In order to reduce the humidity in the supply flow path, it is effective to increase the amount of oxidizing gas relative to moisture, that is, increase the amount of primary oxidizing gas supplied to the fuel pulverization unit.
However, when the amount of the primary oxidizing gas supplied to the fuel pulverization unit is increased, the amount of the pulverized solid fuel increases, and the solid fuel having a coarse particle size reaches the classification unit for classifying the fine fuel. .
And if finely divided fuel reaches a classification part to a solid fuel with a coarse particle size, there exists a problem that the precision of classification of finely divided fuel will worsen.

  The present invention has been made in view of such circumstances, and pulverized fuel is deposited in a supply channel for supplying classified pulverized fuel to a burner unit without degrading the classification accuracy of the pulverized fuel. It is an object of the present invention to provide a solid fuel pulverization apparatus and an operation method thereof that can suppress such a problem.

In order to achieve the above object, the present invention employs the following means.
A solid fuel pulverizing apparatus according to the present invention includes a pulverizing unit that pulverizes solid fuel, and a classification unit that is provided above the pulverizing unit and classifies the solid fuel pulverized by the pulverizing unit into a pulverized fuel smaller than a predetermined particle size. A primary oxidizing gas blowing section for blowing a primary oxidizing gas for supplying the solid fuel pulverized by the pulverizing section to the classification section, and preheating the primary oxidizing gas supplied to the pulverizing section. A preheating unit, a supply flow path for supplying the pulverized fuel classified by the classification unit together with the primary oxidizing gas preheated by the preheating unit to a burner unit for burning the pulverized fuel, and the preheating unit. A bypass flow path that bypasses the preheated primary oxidizing gas to the supply flow path without passing through the pulverizing section and the classification section.

  According to the solid fuel pulverization apparatus according to the present invention, the solid fuel pulverized by the pulverization unit is supplied to the classification unit by the primary oxidizing gas preheated by the preheating unit, and the fine powder having a particle size smaller than the predetermined particle size in the classification unit. Classified as fuel. Further, the primary oxidizing gas mixed with the pulverized fuel is supplied to the burner unit for burning the pulverized fuel through the supply channel. The primary oxidizing gas preheated by the preheating unit is guided to the supply channel without passing through the pulverization unit and the classification unit via the bypass channel.

  By doing in this way, the preheated primary oxidizing gas is guide | induced to the supply flow path which guides pulverized fuel to a burner part, without increasing the flow volume of the primary oxidizing gas which passes a crushing part and a classification part. Accordingly, there is provided a solid fuel pulverization apparatus capable of suppressing a problem that pulverized fuel accumulates in a supply flow path for supplying classified pulverized fuel to a burner unit without degrading the classification accuracy of the pulverized fuel. be able to.

  In the solid fuel pulverization apparatus according to the first aspect of the present invention, the supply channel is connected to the classification unit, and the upstream supply channel that guides the primary oxidizing gas mixed with the pulverized fuel to the upper side of the classification unit. And a downstream supply passage for horizontally guiding the primary oxidizing gas mixed with the pulverized fuel supplied from the upstream supply passage, and the bypass passage is preheated by the preheating unit. The primary oxidizing gas is bypassed to the upstream supply flow path.

  The solid fuel pulverization apparatus according to the first aspect of the present invention includes an upstream supply channel that is connected to the classification unit and guides the mixed oxidizing gas of the pulverized fuel to the upper side of the classification unit, and an upstream supply channel. And a downstream supply passage that guides the mixed oxidizing gas of pulverized fuel supplied from the horizontal direction in the horizontal direction, the bypass passage bypasses the primary oxidizing gas to the upstream supply passage. In this way, the primary oxidizing gas introduced from the bypass channel surely flows into the downstream supply channel where pulverized fuel is likely to accumulate, so the supply flow for supplying the classified pulverized fuel to the burner unit The problem that pulverized fuel accumulates in the road can be more reliably suppressed.

  The solid fuel pulverization apparatus according to the second aspect of the present invention includes a flow rate adjusting valve that is disposed in the bypass flow path and is capable of adjusting an air volume of the primary oxidizing gas that passes through the bypass flow path. In this way, considering the amount of moisture contained in the solid fuel, the amount of moisture contained in the primary oxidizing gas blown by the blower, the temperature of the supply flow path, etc., the primary oxidizing gas at an appropriate flow rate Can be circulated through the bypass flow path.

  The solid fuel pulverization apparatus according to a third aspect of the present invention includes a control unit that controls an air volume of the primary oxidizing gas blown by the primary oxidizing gas blowing unit and an opening degree of the flow rate adjusting valve, and the control unit includes: The flow rate adjusting valve and the primary oxidizing gas blowing unit reduce the air volume of the primary oxidizing gas blown by the primary oxidizing gas blowing unit in response to decreasing the opening of the flow rate adjusting valve. It is characterized by controlling.

  The solid fuel pulverization apparatus according to the third aspect of the present invention is configured to reduce the air volume of the primary oxidant gas blown by the primary oxidant gas blower as the opening degree of the flow rate control valve is reduced. And a control unit for controlling the primary oxidizing gas blowing unit. By doing in this way, the problem that the flow rate of the primary oxidizing gas supplied to the pulverization unit varies depending on whether the primary oxidizing gas bypasses (bypasses) through the bypass flow path or not. Can be prevented.

  A solid fuel pulverizing apparatus according to a fourth aspect of the present invention includes a first flow path through which the primary oxidizing gas blown from the primary oxidizing gas blowing unit is circulated without passing through the preheating unit, and the primary oxidizing property. The primary oxidizing gas blown from the gas blowing section is supplied from the second flow path through the preheating section, the primary oxidizing gas supplied from the first flow path, and the second flow path. A third flow path that mixes the primary oxidizing gas to be supplied to the pulverization unit, and the bypass flow path is a flow path that connects the third flow path and the supply flow path. It is characterized by that.

  In the solid fuel pulverization apparatus according to the fourth aspect of the present invention, the primary oxidizing gas blown from the primary oxidizing gas blowing section flows without passing through the first flow path through the preheating section and the preheating section. Branches to the second flow path. Thereafter, the branched primary oxidizing gas joins in the third flow path and is supplied to the pulverization unit. By doing in this way, the primary oxidizing gas adjusted to appropriate temperature can be supplied to a supply flow path via a bypass flow path.

  In the solid fuel pulverizing apparatus according to the fifth aspect of the present invention, the preheating part is provided between the primary oxidizing gas blowing part and the pulverizing part, and the primary air blown by the primary oxidizing gas blowing part. The preheating unit preheats the oxidizing gas. By doing in this way, after preheating the primary oxidizing gas blown by the primary oxidizing gas blowing part, it can be supplied to the grinding part.

  In the solid fuel pulverization apparatus according to the sixth aspect of the present invention, the preheating part is provided upstream of the primary oxidizing gas blowing part, and the oxidizing gas preheated by the preheating part is blown into the primary oxidizing gas blowing part. The section is blown as the primary oxidizing gas. By doing in this way, the oxidizing gas preheated by the preheating part can be blown as primary oxidizing gas.

  The solid fuel pulverizing apparatus according to a seventh aspect of the present invention is characterized in that the primary oxidant gas blowing unit includes an indentation blowing unit that blows an oxidizing gas. By doing in this way, sufficient primary oxidizing gas can be supplied to a grinding | pulverization part using a forced air blowing part with a primary oxidizing gas blowing part.

  An operation method of a solid fuel pulverization apparatus according to the present invention includes a pulverization unit that pulverizes solid fuel, and classifies the solid fuel that is provided above the pulverization unit and is pulverized by the pulverization unit into a pulverized fuel smaller than a predetermined particle size A classifying unit, a primary oxidizing gas blowing unit for blowing a primary oxidizing gas for supplying the solid fuel pulverized by the pulverizing unit to the classifying unit, and the primary oxidizing gas supplied to the pulverizing unit. A solid fuel comprising: a preheating part for preheating; and a supply flow path for supplying the finely divided fuel classified by the classification part to a burner part for burning the finely divided fuel together with the primary oxidizing gas preheated by the preheating part. A method of operating a pulverizing apparatus, the step of blowing a primary oxidizing gas for supplying the solid fuel pulverized by the pulverizing unit to the classifying unit to the pulverizing unit, and a preheating by the preheating unit. It said primary oxidizing gas without passing through the crushing unit and the classifying unit, characterized in that it and a step of bypassing the said supply passage through the bypass passage.

  According to the operation method of the solid fuel pulverization apparatus according to the present invention, the solid fuel pulverized by the pulverization unit is supplied to the classification unit by the primary oxidizing gas preheated by the preheating unit, Even small pulverized fuel is classified. Further, the primary oxidizing gas mixed with the pulverized fuel is supplied to the burner unit for burning the pulverized fuel through the supply channel. The primary oxidizing gas preheated by the preheating unit is guided to the supply channel without passing through the pulverization unit and the classification unit via the bypass channel.

  By doing in this way, the preheated primary oxidizing gas is guide | induced to the supply flow path which guides pulverized fuel to a burner part, without increasing the flow volume of the primary oxidizing gas which passes a crushing part and a classification part. Therefore, the operation method of the solid fuel pulverization apparatus that can suppress the problem that the pulverized fuel accumulates in the supply flow path for supplying the classified pulverized fuel to the burner unit without deteriorating the classification accuracy of the pulverized fuel. Can be provided.

  According to the present invention, solid fuel pulverization that can suppress the problem of pulverized fuel accumulating in the supply channel for supplying the classified pulverized fuel to the burner unit without degrading the classification accuracy of the pulverized fuel. An apparatus and a method for operating the apparatus can be provided.

It is a lineblock diagram showing the coal crusher of a 1st embodiment. It is sectional drawing which shows the coal grinding | pulverization part of 1st Embodiment. It is sectional drawing which shows the roller and roller support part of 1st Embodiment. It is a flowchart which shows the process of the control part of 1st Embodiment. It is a flowchart which shows the process of the control part of 2nd Embodiment. It is a block diagram which shows the coal grinding | pulverization apparatus of 3rd Embodiment.

[First Embodiment]
Hereinafter, in the first embodiment, a coal pulverization apparatus which is an example of a solid fuel pulverization apparatus will be described with reference to FIG. Drawing 1 is a lineblock diagram showing the coal crusher of a 1st embodiment. In the present embodiment, air is used as an example of the oxidizing gas.
A coal pulverization apparatus (solid fuel pulverization apparatus) 1 according to the first embodiment preheats a coal pulverization unit 10, a coal supply unit 36 that supplies coal to the coal pulverization unit 10, and primary air blown to the coal pulverization unit 10. And a primary air fan 90 that blows air preheated by the air preheater 40 to the coal crushing unit 10 as primary air.

Further, the coal pulverizer 1 bypasses the primary air from the primary air fan 90 to the upstream supply passage 105 from the boiler 60 including the burner unit 110 that burns the pulverized coal supplied from the coal pulverization unit 10. A flow rate adjusting valve 70c disposed on the bypass flow path 104 is provided. The flow rate adjustment valve 70c is a valve whose opening degree can be adjusted by driving an electric motor.
The coal pulverization apparatus 1 includes a control unit 50 that controls each part of the coal pulverization apparatus 1 such as the coal pulverization unit 10, the coal supply unit 36, the pushing fan 80, and the primary air fan 90.

Next, the flow of air in the coal pulverizer 1 will be described.
Air outside the coal pulverizer 1 flows from the flow path 100 by the pushing fan 80. A part of the air flowing in from the flow path 100 by the pushing fan 80 is preheated from the flow path 101 via the air preheater 40, and the preheated air is supplied to the burner unit 110 via the flow path 109. The air supplied to the burner unit 110 via the flow path 109 is used as secondary air for the combustion of pulverized coal in the burner unit 110.

  Another part of the air that has flowed in from the flow path 100 by the pushing fan 80 flows into the primary air fan 90 and is blown by the primary air fan 90 to the flow path 102a. Part of the air blown to the flow path 102 a is preheated by the air preheater 40, and the preheated air joins the flow path 102 b through the flow path 103. Another part of the air blown to the flow path 102a is blown to the flow path 102b without passing through the air preheater 40. At the position where the flow path 102a and the flow path 103 merge, the air preheated by the air preheater 40 and the air that has not been preheated by the air preheater 40 are mixed, and the coal pulverization unit 10 is passed through the flow path 102b. Be blown.

  After the air passing through the flow path 102 a and the air passing through the flow path 103 are mixed at the merge position, a part thereof flows into the bypass flow path 104, and the other part flows into the coal pulverization unit 10. As will be described later, the air (primary air) flowing into the coal pulverization unit 10 is mixed with pulverized coal in the coal pulverization unit 10, passes through the upstream supply channel 105 and the downstream supply channel 106, and then burner unit 110. To be supplied. In the burner unit 110, the mixed air of the pulverized coal supplied from the coal pulverizing unit 10 is used as primary air, and the air supplied from the air preheater 40 is used as the secondary air, so that the pulverized coal is burned.

  As shown in FIG. 1, the upstream supply channel 105 is a channel that guides the primary air mixed with the pulverized coal discharged from the coal pulverization unit 10 upward. Further, as shown in FIG. 1, the downstream supply channel 106 is a channel that guides the mixed air (primary air) supplied from the upstream supply channel 105 in the horizontal direction. The downstream supply channel 106 is connected to the burner unit 110.

  In the boiler 60, heat is generated by applying heat generated by the combustion of pulverized coal in the burner unit 110 to steam flowing through a steam pipe (not shown). The steam having a high temperature is used as power for rotating a steam turbine (not shown). From the boiler 60, high-temperature combustion gas is supplied to the air preheater 40 via the flow path 112 and then discharged to the outside of the coal pulverization apparatus 1 via the flow path 111. The reason why the high-temperature combustion gas is supplied to the air preheater 40 via the flow path 112 is that the high-temperature combustion gas is used as a heat source for preheating the air.

  What is characteristic of the first embodiment is that the entire amount of primary air blown by the primary air fan 90 is not guided to the coal pulverizing unit 10, but a part of the primary air is diverted to the bypass flow path 104, and the upstream supply flow It is at a point leading to the path 105. With such a configuration, it is possible to guide the primary air preheated by the air preheater 40 to the upstream supply flow path 105 without increasing the flow rate of the primary air supplied to the coal pulverization unit 10. . By guiding the primary air preheated by the air preheater 40 to the upstream supply flow path 105, it is possible to suppress a problem that moisture is condensed inside the downstream supply flow path 106. And the malfunction that pulverized coal accumulates in the inside of the downstream supply flow path 106 can be suppressed by suppressing the malfunction that moisture condenses.

Next, the coal grinding | pulverization part 10 is demonstrated in detail using FIG. FIG. 2 is a cross-sectional view illustrating the coal pulverization unit of the first embodiment.
The coal pulverization unit 10 includes a hollow housing 11 having a substantially cylindrical shape, a rotary table 12 that is disposed in a lower portion of the housing 11 and that is rotatably mounted around an axis extending in the vertical direction, and an outer periphery of the rotary table 12. The roller 12 (pulverization part) 13 which is pressed by the part 12b and cooperates with the rotary table 12 to crush coal, and the drive part 14 which rotates the rotary table 12 are provided. The drive unit 14 includes an electric motor and a speed reducer, and a speed reducer that decelerates the number of rotations of the electric motor is connected to the central portion 12a of the rotary table 12 via a rotating shaft.

  The coal pulverization unit 10 supplies the classification unit 16 disposed at the upper part in the housing 11 and the coal that is attached so as to penetrate the upper end of the housing 11 and is supplied from the upper part to the central part 12 a of the turntable 12. And a coal input unit 17. The lower end portion of the housing 11 communicates with the flow path 102b, and primary air flows from the flow path 102b to the lower end portion of the housing 11. The housing 11 is fixed to the upper surface of a pair of rectangular parallelepiped concrete blocks 19 installed on the floor 18.

  In FIG. 2, only one roller 13 is shown, but a plurality of rollers 13 are arranged at regular intervals in the outer circumferential direction so as to press the outer circumferential portion 12 b of the rotary table 12. For example, three rollers 13 are arranged on the outer peripheral portion 12b with an angular interval of 120 °. In this case, the portions where the three rollers 13 are in contact with the outer peripheral portion 12 b of the rotary table 12 (the portions to be pressed) are equidistant from the central portion 12 a of the rotary table 12.

  At a plurality of locations outside the turntable 12, air outlets 32 are provided for allowing the primary air flowing from the flow path 102 b to flow out into the space above the turntable 12 in the housing 11. A vane 33 is installed above the air outlet 32, and the vane 33 gives a turning force to the primary air blown out from the air outlet 32. The primary air to which the turning force is given by the vane 33 becomes an air current as shown by an arrow in FIG. 2, and guides the coal pulverized on the rotary table 12 to the classification unit 16 above the housing 11. Of the pulverized coal mixed with the primary air, the one having a large particle size falls without reaching the classification unit 16 and is returned to the rotary table 12 again.

  The classifying unit 16 includes a blade that rotates about the cylindrical axis of the substantially cylindrical housing 11. The pulverized coal that has reached the classifying section 16 has only the pulverized coal smaller than the predetermined particle size flow into the blade due to the relative balance between the centrifugal force and the centripetal force generated by the rotating blade and the flow of primary air. 34 flows out. The outlet 34 communicates with the upstream supply channel 105.

  Next, the structure of the roller 13 and the roller support part 20 is demonstrated using FIG. The roller 13 is supported on the housing 11 by a roller support portion 20. The roller support unit 20 includes a support shaft 21 to which the roller 13 is attached, a boss 22 that holds the support shaft 21, a rotary shaft 23 that is fixedly attached to the side of the boss 22, and an upper surface of the boss 22. The arm 24 is attached so as to exist, and the protrusion 25 is provided on the lower surface of the boss 22 so as to protrude downward.

A hollow hub 26 having a substantially cylindrical shape is attached to the center of the roller 13. The roller 13 is attached to the tip end portion of the support shaft 21 via the hub 26. Therefore, the roller 13 is rotatable in the circumferential direction around the support shaft 21.
The rotary shaft 23 is arranged so that the axis is substantially horizontal and extends in the tangential direction of the circular shape of the rotary table 12. The roller support portion 20 is rotatable about the rotation shaft 23, and the distance of the roller 13 relative to the outer peripheral portion 12 b of the rotary table 12 changes by rotating about the rotation shaft 23.

  A load applying portion 27 that presses the upper end portion of the arm 24 is attached to the housing 11. The load adding portion 27 includes a slider 28 attached to the housing 11 so as to be movable in the longitudinal direction, and a hydraulic load portion 29 attached to the outer periphery of the housing 11 to press the outer end portion of the slider 28. The inner end portion of the slider 28 is connected to the outer peripheral side of the upper end portion of the arm 24. The load adding unit 27 swings the roller support unit 20 around the rotation shaft 23 by moving the slider 28 in the longitudinal direction by the hydraulic load unit 29.

  The protrusion 25 abuts against the stopper 30 when the roller support 20 swings to a certain position around the rotation shaft 23. The stopper 30 functions as a limiting member that limits the amount of movement of the roller 13 in the direction in which the rotary table 12 is pressed. The stopper 30 is a screw member in which a male screw is carved on the outer peripheral surface, and is screwed with a female screw carved on the inner circumference of the holding portion 31 attached so as to penetrate the housing 11. The stopper 30 can be manually rotated with a dedicated special tool. Thereby, the relative position of the roller 13 with respect to the rotary table 12 when it is closest to the rotary table 12 can be adjusted.

Next, operation | movement of the coal pulverization apparatus 1 is demonstrated using FIG. FIG. 4 is a flowchart showing processing of the control unit 50 of the coal pulverizer 1. The control unit 50 executes each process shown in the flowchart of FIG. 4 by executing a program stored in a storage unit included in the control unit 50.
In step S401, the control unit 50 starts warming of the coal pulverizer 1. Here, the warming refers to a process of warming the inside of the housing 11 of the coal pulverizing unit 10 by flowing primary air into the coal pulverizing unit 10 in advance. In this warming, when coal is fed into the cold coal pulverization unit 10, the coal is not sufficiently dried, and the upstream flow channel 105 and the downstream flow channel 106 that are outlets of pulverized coal from the coal pulverization unit 10. The purpose is to prevent pulverized coal from settling and accumulating due to condensation. The control unit 50 operates the pushing fan 80 and the primary air fan 90 to cause the primary air preheated by the air preheater 40 that exchanges heat with the exhaust gas of the boiler 60 to flow into the coal pulverization unit 10.

In step S402, the control unit 50 detects the output of a temperature sensor provided near the outlet of the coal pulverizing unit 10, and determines whether or not the detected temperature is equal to or higher than a predetermined temperature (for example, 70 ° C.). When it is determined that the temperature has become equal to or higher than the predetermined temperature, the control unit 50 advances the process to step S403.
In step S403, the control unit 50 instructs the coal supply unit 36 to start coal supply. The coal supply unit 36 that has received an instruction from the control unit 50 starts supplying coal to the coal input unit 17 of the coal crushing unit 10.

In step S404, the control unit 50 instructs the flow rate adjustment valve 70c to open the flow rate adjustment valve 70c. The flow rate adjustment valve 70c that has received an instruction from the control unit 50 opens the valve so that the primary air from the flow path 102b flows through the bypass flow path 104. When the primary air flows through the bypass flow path 104, the primary air can be bypassed to the upstream supply flow path 105 without passing through the coal pulverization unit 10.
The opening degree of the valve when the flow regulating valve 70c is opened takes into consideration the moisture content of coal, the moisture content of primary air blown by the primary air fan 90, the temperature of the supply flow path, etc. Therefore, it is desirable to set appropriately.
In step S405, the control unit 50 instructs to set the rotational speed of the fan so that the air volume blown by the primary air fan 90 becomes the first air volume. The primary air fan 90 that has received an instruction from the control unit 50 sets the rotational speed of the fan so that the air volume blown by the primary air fan 90 becomes the first air volume.

In step S406, the control unit 50 detects the output of a humidity sensor provided near the outlet of the coal pulverizing unit 10, and determines whether the detected humidity is equal to or lower than a predetermined humidity. When it is determined that the detected humidity is equal to or lower than the predetermined humidity, the control unit 50 advances the process to step S407.
In step S407, the control unit 50 instructs to set the rotational speed of the fan so that the air volume blown by the primary air fan 90 becomes the second air volume. The primary air fan 90 that has received an instruction from the control unit 50 sets the rotational speed of the fan so that the air volume blown by the primary air fan 90 becomes the second air volume.
In step S408, the control unit 50 instructs the flow rate adjustment valve 70c to close the flow rate adjustment valve 70c. The flow rate adjustment valve 70 c that has received an instruction from the control unit 50 closes the valve so that the primary air from the flow path 102 b does not flow through the bypass flow path 104.

Here, when the first air volume is set in step S405, the air volume of the primary air flowing through the bypass flow path 104 is defined as the bypass air volume. The second air volume set in step S407 is an air volume obtained by subtracting the bypass flow rate from the first air volume.
When the first air volume is set in step S <b> 405, the primary air for the bypass air volume out of the primary air of the first air volume blown by the primary air fan 90 flows through the bypass flow path 104. Then, primary air corresponding to the second flow rate obtained by subtracting the bypass air volume from the first air volume flows into the coal pulverization unit 10.
On the other hand, when the second air volume is set in step S407, primary air does not flow through the bypass flow path 104, and primary air corresponding to the second air volume flows into the coal pulverization unit 10.
As described above, by controlling the air volume of the primary air blown by the primary air fan 90, the coal pulverization is performed in both cases where the flow rate adjustment valve 70c is opened and when the flow rate adjustment valve 70c is closed. The air volume of the primary air flowing into the section 10 can be made constant (second air volume).

  In step S409, the control unit 50 determines whether or not to end the operation of the coal pulverizer 1, and ends the processing of FIG. 4 when determining to end the operation.

  As described above, according to the coal pulverization apparatus 1 of the first embodiment, the coal pulverized by the roller (pulverization unit) 13 is supplied to the classification unit 16 by the primary air preheated by the air preheater 40, The classification unit 16 classifies the pulverized coal smaller than the predetermined particle size. Further, the primary air mixed with the pulverized coal is supplied to the burner unit 110 that burns the pulverized coal through the supply channels (the upstream supply channel 105 and the downstream supply channel 106). The primary air preheated by the air preheater 40 from the roller (pulverization unit) 13 and the supply channel (upstream supply channel 105, downstream supply channel 106) is supplied to the supply channel (upstream supply channel 105, downstream supply channel 106). It is guided without passing through the classification unit 16.

  By doing in this way, the preheated primary air is guided to the supply flow path that guides the pulverized coal to the burner unit 110 without increasing the flow rate of the primary air that passes through the roller (pulverization unit) 13 and the classification unit 16. . Therefore, the problem that pulverized coal accumulates in the supply channel which supplies the classified pulverized coal to the burner unit 110 can be suppressed without degrading the classification accuracy of the pulverized coal.

  Further, the coal pulverization apparatus 1 of the first embodiment includes an upstream supply flow path 105 that has a supply flow path connected to the classification unit 16 to guide mixed air of pulverized coal to the upper side of the classification unit 16, and an upstream supply flow. When it has the downstream supply flow path 106 which guides the mixed air of the pulverized coal supplied from the path 105 in the horizontal direction, the bypass flow path 104 detours (bypasses) the primary air to the upstream supply flow path. By doing in this way, since the primary air led from the bypass flow path 104 surely flows into the downstream supply flow path 106 where pulverized coal tends to accumulate, the supply for supplying the classified pulverized coal to the burner unit 110 A problem that pulverized coal accumulates in the flow path can be more reliably suppressed.

  In addition, the coal pulverization apparatus 1 according to the first embodiment includes a flow rate adjustment valve 70 c that is disposed in the bypass flow path 104 and can adjust the air volume of the primary air that passes through the bypass flow path 104. By doing in this way, considering the amount of moisture contained in the coal, the amount of moisture contained in the primary air blown by the primary air fan 90, the temperature of the supply flow path, etc., the primary air having an appropriate flow rate is bypassed. It becomes possible to distribute to the road.

  Further, the coal pulverization apparatus 1 of the first embodiment is configured so that the flow rate adjustment valve 70c and the primary air flow are reduced so that the primary air blown by the primary air fan 90 is reduced as the opening degree of the flow rate adjustment valve 70c is reduced. A control unit 50 for controlling the air fan 90 is provided. By doing so, there is a problem that the flow rate of the primary air supplied to the roller (pulverization unit) 13 varies depending on whether the primary air is bypassed (bypassed) via the bypass flow path or not. Can be prevented.

  Further, the coal pulverization apparatus 1 according to the first embodiment is configured such that the primary air blown from the primary air fan 90 flows through the air flow path 103 through the air preheater 40 and the air preheater 40. Branches to the path 102a. The flow path 103 is provided with a flow rate adjusting valve 70b capable of adjusting the air volume, and the flow path 102a is provided with a flow rate adjusting valve 70a capable of adjusting the air volume. The flow rate adjustment valve 70 a and the flow rate adjustment valve 70 b are valves whose opening degree can be adjusted by an electric motor controlled by the control unit 50. The air volume of primary air flowing through the flow path 103 and the air volume of primary air flowing through the flow path 103a are adjusted by the flow rate adjusting valve 70a and the flow rate adjusting valve 70b, respectively. The primary air branched into the flow path 102a and the flow path 103 joins in the flow path 102b and is supplied to the coal pulverization unit 10. By adjusting the volume of primary air flowing through the flow path 102a and the volume of primary air flowing through the flow path 103, primary air adjusted to an appropriate temperature is supplied to the supply flow path via the bypass flow path 104. can do. For example, when it is desired to increase the temperature of the primary air, the flow rate of the flow rate adjustment valve 70b is increased to increase the air volume of the flow channel 103, or the flow rate of the flow rate adjustment valve 70a is decreased to reduce the flow rate. What is necessary is just to reduce the air volume of 102a.

  In the coal pulverization apparatus 1 of the first embodiment, the air preheater 40 is provided between the primary air fan 90 and the coal pulverization unit 10, and the primary air blown by the primary air fan 90 is used as the air preheater. 40 is preheated. In this way, the primary air blown by the primary air fan 90 can be preheated and supplied to the coal pulverization unit 10.

  In addition, the coal pulverization apparatus 1 according to the first embodiment includes a pushing fan 80 that blows air to the primary air fan 90. By doing so, a sufficient amount of primary air can be supplied to the coal crushing unit 10 using the pushing fan 80 together with the primary air fan 90.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a flowchart illustrating processing of the control unit of the second embodiment. The control unit 50 executes each process shown in the flowchart of FIG. 5 by executing a program stored in a storage unit included in the control unit 50.
The second embodiment is a modification of the first embodiment, and is the same as the first embodiment except for a part that will be specifically described below.
Further, the process of the flowchart of FIG. 5 is a modification of the process of the flowchart of FIG. The processing from step S501 to step S505 in FIG. 5 is the same as the processing from step S401 to step S405 in FIG.

  In the first embodiment, when it is determined in step S406 that the humidity is equal to or lower than the predetermined humidity, the air volume of the primary air fan 90 is decreased and the flow rate adjustment valve 70c is closed. In contrast, in the second embodiment, when the flow rate adjusting valve 70c is manually closed by the operator of the coal pulverizing apparatus 1 in step S506, the air volume of the primary air fan 90 is reduced.

In step S506 of FIG. 5, the control unit 50 determines whether or not the flow rate adjustment valve 70c is in a closed state. If it is determined that the flow rate adjustment valve 70c is in a closed state, the process proceeds to step S507. The flow rate adjusting valve 70c includes a sensor capable of detecting the open / closed state of the valve. Whether the flow rate adjusting valve 70c is closed by detecting the output of the center provided in the flow rate adjusting valve 70c. Determine if.
As described in the first embodiment, the opening degree of the flow rate adjusting valve 70c can be adjusted by an electric motor. However, the operator of the coal pulverizer 1 can also adjust the opening degree manually. . In the second embodiment, the operator of the coal crusher 1 manually closes the flow rate adjustment valve 70c. Then, it is detected in step S506 that the flow rate adjustment valve 70c is closed.

In step S507, the control unit 50 instructs to set the rotational speed of the fan so that the air volume blown by the primary air fan 90 becomes the second air volume. The primary air fan 90 that has received an instruction from the control unit 50 sets the rotational speed of the fan so that the air volume blown by the primary air fan 90 becomes the second air volume.
In step S508, the control unit 50 determines whether or not to end the operation of the coal pulverizer 1, and ends the process of FIG. 5 when determining to end the operation.

In the second embodiment, when the operator of the coal pulverization apparatus 1 recognizes the operating status of the coal pulverization apparatus 1 and determines that there is no problem that pulverized coal accumulates in the downstream supply passage 106, the flow rate adjustment is performed. The valve 70c is closed. When the closed state of the flow rate adjusting valve 70c is determined, the control unit 50 of the coal pulverizer 1 automatically reduces the air volume of the primary air fan 90.
Then, in the case where the first air volume is set in step S505 and in the case where the second air volume is set in step S507, the air volume of the primary air flowing into the coal pulverizing unit 10 is made the same amount. . That is, when the first air volume is set in step S505, the second air volume set in step S507 is decreased by the amount of the bypass air volume flowing through the bypass flow path 104.
By doing in this way, the trouble which the flow volume of the primary air supplied to the coal pulverization part 10 fluctuates by the case where primary air bypasses (bypass) via the bypass flow path 104 and the case where it is not so is prevented. can do.

[Third Embodiment]
Next, a third embodiment of the present invention will be described.
The third embodiment is a modification of the first embodiment and the second embodiment, and is the same as the first embodiment and the second embodiment, except for the portions specifically described below.
In FIG. 1 corresponding to the first embodiment and the second embodiment, an air preheater 40 is provided between the primary air fan 90 and the coal pulverization unit 10. The type shown in FIG. 1 is called a cold air fan type.
On the other hand, in FIG. 6 corresponding to the third embodiment, the air preheater 40 is provided on the upstream side of the primary air fan 90. The type shown in FIG. 6 is called a hot air fan type.

The flow of air or the like in the coal pulverizer 1 of the third embodiment will be described with reference to FIG.
Air outside the coal pulverizer 1 flows from the flow path 100 by the pushing fan 80. A part of the air flowing from the flow path 100 by the pushing fan 80 is preheated from the flow path 101 via the air preheater 40, and a part of the preheated air is supplied to the burner unit 110 via the flow path 109. Is done. The air supplied to the burner unit 110 via the flow path 109 is used as secondary air for the combustion of pulverized coal in the burner unit 110.

  Another part of the air preheated by the air preheater 40 passes through the flow path 103 and joins the flow path 101. At this joining position, the primary air blown from the pushing fan 80 without passing through the air preheater 40 and the preheated air that has passed through the flow path 103 are mixed and blown to the primary air fan 90. Part of the primary air blown from the primary air fan 90 flows into the bypass flow path 104, and the other part flows into the coal crushing unit 10.

  As described above, in the coal pulverization apparatus 1 of the third embodiment, the air preheater 40 is provided upstream of the primary air fan 90, and the primary air fan 90 converts the air preheated by the air preheater 40. It blows as primary air. By doing in this way, the air preheated by the air preheater 40 can be blown as primary air.

[Other Embodiments]
In 1st Embodiment and 2nd Embodiment, after starting coal supply (step S403, step S503), the flow regulating valve 70c is made into an open state, However, Another aspect may be sufficient. For example, the flow rate adjustment valve 70c may be opened at the same time as or before the start of warming. By doing in this way, at the time of warming before a coal supply start, the humidity of the supply path of the primary air from the coal pulverization part 10 to the burner part 110 can be kept low, and accumulation of pulverized coal can be suppressed.

  Moreover, in 1st Embodiment, although the flow regulating valve 70c was made into the closed state by step S408, another aspect may be sufficient. For example, the flow rate adjustment valve 70c may be set to an arbitrary opening degree that is smaller than the opening degree in step S404 without being closed. By doing in this way, when the humidity is equal to or lower than a predetermined humidity, the flow rate of primary air flowing through the bypass flow path 104 can be reduced in view of the low possibility of pulverized coal accumulation.

  In 1st Embodiment and 2nd Embodiment, although the flow regulating valve 70c was provided on the bypass flow path 104, another aspect may be sufficient. For example, the primary air from the primary air fan 90 may always flow through the bypass flow path 104 without providing the flow rate adjustment valve 70 c on the bypass flow path 104.

1 Coal crusher (solid fuel crusher)
DESCRIPTION OF SYMBOLS 10 Coal grinding | pulverization part 11 Housing 12 Rotary table 13 Roller 14 Drive part 16 Classification part 36 Coal supply part 40 Air preheater 50 Control part 60 Boilers 70a, 70b, 70c Flow control valve 80 Pushing fan 90 Primary air fan 104 Bypass flow path 105 Upstream supply channel 106 Downstream supply channel 110 Burner section

Claims (9)

A pulverizing unit for pulverizing the solid fuel;
A classifying unit provided at an upper part of the pulverizing unit and classifying the solid fuel pulverized by the pulverizing unit into a finely divided fuel smaller than a predetermined particle size;
A primary oxidizing gas blowing section for blowing a primary oxidizing gas for supplying the solid fuel pulverized by the pulverizing section to the classification section;
A preheating unit for preheating the primary oxidizing gas supplied to the pulverization unit;
A supply flow path for supplying the pulverized fuel classified by the classification unit to a burner unit that burns the pulverized fuel together with the primary oxidizing gas preheated by the preheating unit;
A bypass flow path for bypassing the primary oxidizing gas preheated by the preheating section to the supply flow path without passing through the pulverization section and the classification section;
A solid fuel pulverizing apparatus comprising: The supply channel is connected to the classification unit, and an upstream supply channel that guides the primary oxidizing gas mixed with the pulverized fuel to the upper side of the classification unit, and the supply channel supplied from the upstream supply channel A downstream supply passage that guides the primary oxidizing gas mixed with pulverized fuel in a horizontal direction,
2. The solid fuel pulverization apparatus according to claim 1, wherein the bypass flow channel bypasses the primary oxidizing gas preheated by the preheating unit to the upstream supply flow channel.   3. The solid fuel pulverization apparatus according to claim 1, further comprising a flow rate adjustment valve that is disposed in the bypass flow path and is capable of adjusting an air volume of the primary oxidizing gas passing through the bypass flow path. . A controller for controlling the air volume of the primary oxidizing gas blown by the primary oxidizing gas blower and the opening of the flow rate adjustment valve;
The flow control valve and the primary oxidation are controlled so that the control unit decreases the air volume of the primary oxidizing gas blown by the primary oxidizing gas blowing unit in response to decreasing the opening of the flow control valve. The solid fuel pulverization apparatus according to claim 3, wherein the property gas blower is controlled. A first flow path through which the primary oxidizing gas blown from the primary oxidizing gas blowing section flows without passing through the preheating section;
A second flow path through which the primary oxidizing gas blown from the primary oxidizing gas blowing section flows through the preheating section;
A third flow path that mixes the primary oxidizing gas supplied from the first flow path and the primary oxidizing gas supplied from the second flow path and supplies the mixed gas to the pulverization unit,
5. The solid fuel pulverization apparatus according to claim 1, wherein the bypass flow path is a flow path that connects the third flow path and the supply flow path. The preheating part is provided between the primary oxidizing gas blowing part and the pulverization part,
The solid fuel pulverization apparatus according to claim 1, wherein the preheating unit preheats the primary oxidizing gas blown by the primary oxidizing gas blowing unit. The preheating unit is provided upstream of the primary oxidizing gas blowing unit,
The solid fuel pulverization according to any one of claims 1 to 5, wherein the primary oxidizing gas blowing section blows the oxidizing gas preheated by the preheating section as the primary oxidizing gas. apparatus.   The solid fuel pulverization apparatus according to any one of claims 1 to 7, wherein the primary oxidant gas blower includes a push blower for blowing an oxidant gas. A pulverizing unit that pulverizes solid fuel, a classification unit that is provided at an upper portion of the pulverizing unit, classifies the solid fuel pulverized by the pulverizing unit into finely pulverized fuel having a particle size smaller than a predetermined particle size, and the solid fuel pulverized by the pulverizing unit The primary oxidizing gas blowing section for blowing the primary oxidizing gas for supplying the classification section to the classification section, the preheating section for preheating the primary oxidizing gas supplied to the pulverization section, and the classification section A supply flow path for supplying the pulverized fuel to a burner unit for burning the pulverized fuel together with the primary oxidizing gas preheated by the preheating unit,
Blowing a primary oxidizing gas for supplying the solid fuel pulverized by the pulverizing unit to the classifying unit;
Bypassing the primary oxidizing gas preheated by the preheating section to the supply flow path through a bypass flow path without passing through the pulverization section and the classification section;
A method for operating a solid fuel pulverizing apparatus, comprising:

Images