JP2007192417A - Soot blower and method for controlling soot blower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a soot blower capable of surely removing dust attached to a rotating body, and reducing steam wastefully blown out. <P>SOLUTION: In this soot blower 30 for removing dust attached to the cylindrical rotating body 21 of a rotary air preheater 1 exchanging heat between an exhaust gas including dust and air, a control device 60 is disposed to adjust and control a moving speed of a nozzle 37 to an optimum set speed, when the nozzle 37 blowing out a gas is radially reciprocated between a position α for blowing out the gas toward a central portion of a circular plane of the rotating body 21 and a position β for blowing out the gas toward an outer peripheral portion of the circular plane of the rotating body 21. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention, for example, a cylindrical shape provided in a rotary air preheater that exchanges heat between exhaust gas containing dust that exits a combustion engine such as a boiler and air used for combustion by entering the combustion engine such as a boiler The present invention relates to a soot blower for removing dust adhering to a rotating body of the machine and a control method for the soot blower.

  A conventionally known rotary air preheater divides the inside of a cylindrical main body into two semi-cylindrical passages, and one of these two semi-cylindrical passages is exhausted from a combustion engine such as a boiler. The flowing exhaust gas side passage is used, and the other side is an air side passage through which air entering a combustion engine such as a boiler flows. Further, there is provided a rotating body of a heat storage material configured in a cylindrical shape concentrically and with the same diameter as the main body, which can be rotated across both of the exhaust gas side passage and the air side passage that run side by side. This rotating body stores the heat of the exhaust gas in the heat storage material when passing through the exhaust gas side passage, and releases the heat stored in the heat storage material to the air when passing through the air side passage. It is possible to heat the air supplied to the boiler by exchanging heat with it.

  When the above-described rotary air preheater is used to exchange heat between exhaust gas containing dust and air, dust adheres to the heat storage material of the rotating body. The dust adhering to the heat storage material prevents the exhaust gas and air from passing through the heat storage material, lowering the heat exchange efficiency of the rotary air preheater and increasing the pressure loss. In Patent Document 1, this problem is solved by a soot blower that removes dust adhering to the heat storage material of the rotating body. In the soot blower described in Patent Document 1, steam at a constant flow rate (steam containing a mixture) is jetted from a nozzle toward a circular surface on the lower side of a rotating body rotating at a constant speed, and the nozzle is jetted. For example, it is reciprocated at a constant speed in the radial direction to remove dust adhering to the heat storage material of the rotating body.

Japanese Patent Laid-Open No. 5-33920

  However, when removing dust adhering to the heat storage material of the rotating body using the soot blower described in Patent Document 1, the nozzle for injecting a constant flow of steam is reciprocated at a constant speed in the radial direction. As will be described below, there is a difference in the injection amount per unit area of the steam injected onto the circular surface at each radial position.

FIG. 1 shows a nozzle N that injects steam at a constant flow rate W (ton / min) toward a circular surface S having a radius R (m) on the lower side of a rotating body that rotates at a constant speed. / Min) is a schematic diagram in the case where the linear motion is performed in the radial direction from the outer peripheral portion A to the central portion O. With reference to FIG. 1, when the soot blower described in Patent Document 1 is used, the injection amount δ ₁ (ton / m ² ) per unit area of the steam injected to the outer peripheral portion A and the central portion O are injected. Specifically, the injection amount δ ₂ (ton / m ² ) per unit area of steam is calculated. It is assumed that the rotation speed of the rotating body is sufficiently larger than the speed V at which the nozzle N moves in the radial direction.

The nozzle N starting from the outer peripheral portion A advances to the position B after a predetermined time t (min) has elapsed. Since AB = Vt (m), the area S ₁ (m ² ) in the vicinity of the outer periphery A where the nozzle N injects steam during the time required to travel from the outer periphery A to the position B (ie, the predetermined time t (min)). S ₁ = circular portion with radius OA−circular portion with radius OB = πR ² −π (R−Vt) ² . On the other hand, since CO = Vt (m), the nozzle N reaches the center O after the elapse of a predetermined time t (min) after reaching the position C. Accordingly, the area S ₂ (m ² ) in the vicinity of the central portion O where the nozzle N injects steam during the time required to travel from the position C to the central portion O (ie, the predetermined time t (min)) is S ₂ = π (Vt) ² (For the schematic diagram shown in FIG. 1 to hold, the predetermined time t (min) needs to satisfy the relationship of R> Vt.)

Since the amount of steam injected by the nozzle N per unit time is W (ton / min) as described above, the amount of steam δ ₁ (ton / m per unit area) of the steam ejected from the nozzle N to the outer peripheral portion A. ² ) is δ ₁ = W / S ₁ . Further, the injection amount δ ₂ (ton / m ² ) per unit area of the steam injected from the nozzle N to the central portion O is δ ₂ = W / S ₂ . When the values of S ₁ and S ₂ described above are used for these δ ₁ and δ ₂ , the ratio of δ ₁ and δ ₂ is δ ₁ / δ ₂ = S ₂ / S ₁ = {π (Vt) ² } / [ ^{πR 2 -π {R- (Vt)} 2}] = a Vt / (2R-Vt). Since R> Vt as described, δ ₁ / δ ₂ <1, and the value of the injection amount δ ₂ (ton / m ² ) per unit area of the steam that the nozzle N injects into the central portion O is greater. , Larger than the value of the injection amount δ ₁ (ton / m ² ) per unit area of the steam ejected from the nozzle N to the outer peripheral portion A (δ ₁ <δ ₂ ).

For this reason, when the value of the flow rate W (ton / min) injected by the nozzle N is set so that the value of the injection amount δ ₂ (ton / m ² ) per unit area of the central portion O is optimal, the outer peripheral portion The value of the injection amount δ ₁ (ton / m ² ) per unit area of A becomes too small, and the dust on the outer peripheral portion A cannot be completely removed.

On the other hand, when the value of the flow rate W (ton / min) injected by the nozzle N is set so that the value of the injection amount δ ₁ (ton / m ² ) per unit area of the outer peripheral portion A is optimal, the central portion O Since the value of the injection amount δ ₂ (ton / m ² ) per unit area becomes too large, steam is unnecessarily injected into the central portion O, and the cost increases.

  The present invention has been made in view of the above problems, and the injection amount per unit area of a gas such as steam injected toward the circular plane of the rotating body of the rotary preheater is applied to the entire circular plane of the rotating body. It is an object of the present invention to provide a soot blower and a soot blower control method that can reliably remove dust adhering to a rotating body and that is more economical than the conventional one.

  In order to solve the above problems, according to the present invention, there is provided a soot blower for removing dust adhering to a cylindrical rotating body provided in a rotary air preheater that performs heat exchange between exhaust gas containing dust and air. A nozzle for injecting gas toward the circular plane of the rotating body; a first position for injecting gas toward the center of the circular plane of the rotating body; and the circular plane of the rotating body. And a drive mechanism that reciprocates in the radial direction between the second positions for injecting gas toward the outer periphery of the nozzle, and detecting that the nozzle has reached the first position or the second position And a control device for controlling the drive mechanism, the control device controls the drive mechanism so that the nozzle moves at a predetermined moving speed according to a radial position, And the front by the sensor A soot blower is provided that controls the drive mechanism to reverse the direction of movement of the nozzle when it senses that the nozzle has reached the first position or the second position. .

  In the soot blower, the predetermined moving speed is set so that an injection amount per unit area of gas injected by the nozzle toward the circular plane of the rotating body is uniform on the circular plane of the rotating body. It may be.

  The soot blower may include the nozzle, the driving mechanism, the sensor, and the control device for one or both of the circular planes on both sides of the rotating body.

  In the soot blower, the rotary air preheater includes a semi-cylindrical exhaust gas side passage and a semi-cylindrical air side passage, and the rotating body is disposed across the exhaust gas side passage and the air side passage. Also good.

  In the soot blower, the nozzle may be provided in the exhaust gas side passage.

  According to the present invention, there is provided a soot blower that jets and removes gas from a nozzle to the dust attached to a cylindrical rotating body provided in a rotary air preheater that exchanges heat between exhaust gas containing dust and air. In the control method, the nozzle is moved toward the center of the circular plane while rotating the rotating body at a constant rotational speed and injecting a constant flow rate of gas from the nozzle onto the circular plane of the rotating body. Between the first position for injecting gas and the second position for injecting gas toward the outer periphery of the circular plane, the nozzle is moved back and forth in the radial direction. A soot blower control method is provided, wherein the soot blower is moved at a predetermined moving speed according to the position of the soot blower.

  In the soot blower control method, the predetermined moving speed is such that the injection amount per unit area of the gas injected by the nozzle toward the circular plane of the rotating body is uniform on the circular plane of the rotating body. May be set.

  In the soot blower control method, the radial position of the nozzle may be calculated as a movement distance of the nozzle from the first position or the second position.

  In the soot blower control method, the calculated movement distance may be initialized when the nozzle reaches the first position or the second position.

  According to the present invention, dust adhering to a rotating body can be reliably removed by optimizing the injection amount per unit area of a gas such as steam injected onto the rotating body of the rotary preheater. Further, it is possible to reduce the amount of wastefully injected steam, and it is possible to improve the economic efficiency as compared with the prior art.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 2 is a configuration diagram illustrating the configuration of a thermal power generation facility 2 including a rotary air preheater 1 used for carrying out the embodiment of the present invention. The thermal power generation facility 2 includes a boiler 3 for burning coal, a turbine / generator 4 for generating power by rotating a steam turbine (not shown) with steam, and water / steam between the boiler 3 and the turbine / generator 4. It is comprised with the steam pipe 5 to circulate. A coal bunker 6 that supplies coal is connected to the boiler 3 via a crusher 7 that crushes the coal. The thermal power generation facility 2 returns the supply water supplied from the turbine / generator 4 to the turbine / generator 4 as high-temperature and high-pressure steam by combustion heat in the boiler 3 and rotates the steam turbine to generate power. Can be done.

  As shown in FIG. 2, the boiler 3 is connected to an air supply pipe 10 that supplies air when burning coal and an exhaust gas discharge pipe 11 that discharges exhaust gas generated by the combustion of coal. One end of the air supply pipe 10 is connected to the vicinity of the combustion part for burning the coal of the boiler 3, and the other end communicates with the outside. At the other end of the air supply pipe 10, a pusher fan 12 that blows air into the boiler 3 is provided. One end of the exhaust gas discharge pipe 11 is connected to the upper part of the boiler 3, and the other end is connected to a chimney 13 that exhausts exhaust gas. The other end of the exhaust gas discharge pipe 11 is provided with an induction blower 14 that sucks exhaust gas from the boiler 3 and sends it to the chimney 13 side.

The exhaust gas exhaust pipe 11 is provided with a denitration device 15 that removes NO _X from the exhaust gas and an electric dust collector 16 that removes and cleans harmful substances such as soot from the exhaust gas along the traveling direction of the exhaust gas.

  The rotary air preheater 1 is provided across the exhaust gas discharge pipe 11 between the denitration device 15 and the electrostatic precipitator 16 and the air supply pipe 10. FIG. 3 is a perspective view showing a simple configuration of the rotary air preheater 1.

  As shown in FIG. 3, the rotary air preheater 1 has a configuration in which a cylindrical rotating body 21 that is rotatable around the same axis as the casing 20 is provided inside a cylindrical casing 20. The rotating body 21 is made of a material having good thermal conductivity such as metal, and is rotated by the rotor 22 at the center. The inside of the casing 20 is divided into two by a radial partition 23 including a rotor 22 at the center, and two semi-cylindrical spaces 24 and 25 are formed. One semi-cylindrical space 24 communicates with the air supply pipe 10 on the upper side and the lower side so that the air supplied to the boiler 3 flows from the lower side to the upper side along the axial direction and passes through the rotating body 21. It is configured. The other semi-cylindrical space 25 communicates with the exhaust gas discharge pipe 11 on the upper side and the lower side, and the exhaust gas containing dust discharged from the boiler 3 flows from the upper side to the lower side along the axial direction. It is configured to pass.

  FIG. 4 is a plan view of the rotary air preheater 1 including the soot blowers 30 and 31 according to the embodiment of the present invention. FIG. 5 is a side view of the rotary air preheater 1 of FIG. 4 as viewed in the X direction. FIG. 6 is a side view of the rotary air preheater 1 of FIG. 4 as viewed in the Y direction.

  The soot blowers 30 and 31 are provided on the space 25 side where the exhaust gas flows. The soot blower 30 is provided on the upper side of the rotary air preheater 1, and the soot blower 31 is provided on the lower side of the rotary air preheater 1. Since the soot blowers 30 and 31 are configured in the same manner and function in the same manner, the soot blower 30 will be described below.

  The soot blower 30 has a main body 35 provided at a position higher than the circular plane (that is, the upper surface) of the radius R of the rotating body 21, and extends parallel to the circular plane from the main body 35, and can swing along the circular plane. A supply pipe 36 and a nozzle 37 provided at the tip of the supply pipe 36 and capable of injecting gas such as steam supplied through the supply pipe 36 toward the circular plane of the rotating body 21 are configured. The supply pipe 36 has a position α as a first position where the nozzle 37 is disposed immediately above the center of the rotating body 21 and a second position where the nozzle 37 is disposed immediately above the outer peripheral portion of the rotating body 21. It is possible to swing back and forth between the position β.

  FIG. 7 is an enlarged plan view of the main body 35 of the soot blower 30. In the present embodiment, the drive mechanism of the soot blower 30 includes the supply pipe 36 provided with the nozzle 37, the rotary shaft 41, the lever 42, the shaft 45, the motor 47, and the bevel gear 48 provided on the support body 40 of the main body 35. 49, as will be described later, the rotation (forward / reverse) of the motor 47 is changed into the swinging motion of the supply pipe 36 through the reciprocating motion of the shaft 45 back and forth and the swinging motion of the lever 42. By converting, the nozzle 37 is configured to reciprocate in the radial direction of the rotating body 21.

  The rotating shaft 41 arranged in the vertical direction is rotatably provided on the support body 40. A lever 42 and a supply pipe 36 are horizontally coupled to the rotary shaft 41. The lever 42 and the supply pipe 36 are disposed so that their longitudinal directions are orthogonal to each other. The support body 40 is provided with a housing 43, and the supply pipe 36 swings in the housing 43. The lever 42, the supply pipe 36, and the rotation shaft 41 are integrated. When the lever 42 is rotated by a predetermined angle, the supply pipe 36 is rotated by the same predetermined angle via the rotation shaft 41. In the present embodiment, the lever 42 includes a position α ′ (position indicated by a one-dot chain line in FIG. 7) at which the supply pipe 36 is disposed at the position α and a position β ′ at which the supply pipe 36 is disposed at the position β. It is possible to rotate between.

  The tip of the lever 42 is pivotally connected to a pin 46 formed at the tip of the shaft 45 that can reciprocate linearly back and forth. As the shaft 45 reciprocates linearly back and forth, the lever 42 can be rotated within a range of a predetermined angle. A long hole that engages the pin 46 is formed at the tip of the lever 42 so that the lever 42 can swing in conjunction with the reciprocating linear movement of the shaft 45.

  The support body 40 is provided with a motor 47 that can be rotated in both forward and reverse directions to drive the shaft 45 forward and backward while rotating. In the present embodiment, a motor capable of inverter control of the direction and number of rotations is used as the motor 47. The drive shaft of the motor 47 is arranged so as to be orthogonal to the shaft 45, and a bevel gear 49 fixed to the drive shaft of the motor 47 and a bevel gear 48 rotatably mounted on the shaft 45 mesh with each other. The rotation is transmitted between the two (bevel gears 48 and 49). Here, the outer peripheral surface of the shaft 45 has a male screw shape, and the shaft 45 penetrates through the male screw portion formed in the bevel gear 48. Accordingly, the rotation of the motor 47 is transmitted to the bevel gear 48 via the bevel gear 49, and the shaft 45 can be moved back and forth by the rotation of the bevel gear 48.

  The main body 35 is provided with a first sensor 50 capable of sensing that the lever 42 has reached the position α ′, and a second sensor 51 capable of sensing that the lever 42 has reached the position β ′. . In the present embodiment, when the lever 42 reaches the position α ′, the pin 46 provided at the tip of the shaft 45 presses the contact portion of the first sensor 50, so that the position α ′ of the lever 42 is reached. It is configured to sense the arrival at. Similarly, when the lever 42 reaches the position β ′, the pin 46 provided at the tip of the shaft 45 presses the contact portion of the second sensor 51, so that the lever 42 reaches the position β ′. Is configured to sense.

  The soot blower 30 includes a control device 60 capable of inverter-controlling the rotation direction and the rotation speed of the motor 47. The control device 60 is configured to control the rotation speed of the motor 47 based on the radial position r of the nozzle 37 provided at the tip of the supply pipe 36. In the present embodiment, the radial distance r from the center position α of the rotating body 21 is defined as the radial position r. The control device 60 is connected to the first sensor 50 and the second sensor 51, and can receive signals from the first sensor 50 and the second sensor 51. As a result, the control device 60 senses the arrival of the lever 42 at the position α ′ by sensing the arrival of the lever 42 at the position α ′, and also reaches the position β ′ of the lever 42 by reaching the position α ′. The supply pipe 36 is configured to sense the arrival at the position β.

  A method for controlling a soot blower according to an embodiment of the present invention that removes dust adhering to the rotating body 21 of the rotary air preheater 1 using the soot blower 30 according to the embodiment of the present invention configured as described above. This will be described with reference to FIGS. FIG. 8 is an overall flowchart showing the procedure of the soot blower control method according to the embodiment of the present invention. FIG. 9 is a flowchart showing a detailed control procedure for controlling the motor 47 so as to control the moving speed of the nozzle 37 based on the current position r in the radial direction of the nozzle 37 in FIG.

  When the soot blower 30 is started and the removal of dust attached to the rotating body 21 of the rotary air preheater 1 is started (SP0), the control device 60 initializes the current position r in the radial direction of the nozzle 37 (SP1). ). When the nozzle 37 is arranged at the position α, the current position r in the radial direction of the nozzle 37 is set to r = 0, and when the nozzle 37 is arranged at the position β, This is performed by setting the current position r in the radial direction of the nozzle 37 to r = R (R is the radius of the circular plane of the rotating body 21). Here, a case where the soot blower 30 is activated in a state where the nozzle 37 is disposed at the position β will be described. Therefore, the current position r in the radial direction of the nozzle 38 is set as r = R.

  The control device 60 controls the rotational speed ω of the motor 47 based on the current position r in the radial direction of the nozzle 37 so that the moving speed v in the radial direction of the nozzle 37 becomes an optimum value (SP2). The control procedure for controlling the rotational speed ω of the motor 47 will be described in detail with reference to FIG.

The control device 60 calculates the current position r in the radial direction of the nozzle 37 (SP2A). At this timing, immediately after initialization, the position r in the radial direction of the nozzle 37 is r = R. The control device 60 calculates the optimum set speed v _set of the nozzle 37 from the calculated current position r in the radial direction of the nozzle 37 (SP2B). In the present embodiment, when calculating the optimum set speed v _set of the nozzle 37 from the current position r in the radial direction of the nozzle 37, it is calculated using the swing function shown in FIG. The swing function shown in FIG. 10 is obtained when the injection amount per unit area of the gas injected from the nozzle 37 is uniform at any position in the radial direction. ) And the set speed v _set .

The control device 60 calculates a set rotation speed ω _set that needs to be _set in the motor 47 in order to obtain the calculated optimum setting speed v _set of the nozzle 37 (SP2C). The set rotational speed ω _set can be calculated based on the length of the supply pipe 36 in the longitudinal direction. The control device 60 performs inverter control of the motor 47 to set the current rotational speed ω _real to the set rotational speed ω _set (SP2D). The nozzle 37 is driven by a motor 47 having a set rotational speed ω _set while jetting a gas such as steam toward the circular plane of the rotary air preheater 1, and the position β is _set at an optimal set speed v _set. Move toward position α.

As shown in FIG. 9, after setting the set rotational speed ω _set for the motor 47, the control device 60 again calculates the current position r in the radial direction of the nozzle 37 (SP2A). Current position r in the radial direction of the nozzle 37, time that has elapsed since the set nozzle 37 to the set speed v _{The set,} a value obtained by multiplying the set speed v _{The set} of nozzles 37, cumulative addition from the time of initialization This can be calculated. Next, an optimum set speed v _set of the nozzle 37 is calculated based on the calculated current position r in the radial direction of the nozzle 37 (SP2B), and a set rotation speed ω _set of the motor 47 is calculated based on the calculated set speed. (SP2C), the calculated set rotational speed ω _set is _set in the motor 47 (SP2D). In the same manner, the above procedure is repeated.

  As described above, the control procedure shown in FIG. 9 for controlling the rotational speed ω of the motor 47 is repeated until the nozzle 37 reaches the position α from the position β (No in SP3), and the nozzle 37 is set at each radial position. Move at the optimum setting speed. Eventually, the nozzle 37 reaches the position α from the position β (Yes in SP3). When the first sensor 50 senses that the lever 42 has reached the position α ′, the control device 60 senses that the nozzle 37 has reached the position α. The control device 60 that senses that the nozzle 37 has reached the position α sets the rotation of the motor 47 in the reverse direction so as to reverse the direction of movement of the nozzle 37 from the position α toward the position β (SP4). ).

  The control device 60 initializes the current position r in the radial direction of the nozzle 37. Since the nozzle 37 has reached the position α, r = 0 is set (SP1). The control device 60 rotates the motor 47 in accordance with the control procedure shown in FIG. 9 described above so that the radial movement speed v of the nozzle 37 becomes an optimum value based on the current position r of the nozzle 37 in the radial direction. The number ω is controlled (SP2). This control procedure is repeated until the nozzle 37 reaches the position β from the position α (No in SP3), and the nozzle 37 is moved at the optimum set speed at each position in the radial direction. Eventually, the nozzle 37 reaches the position β from the position α (Yes in SP3). When the second sensor 51 senses that the lever 42 has reached the position β ′, the control device 60 senses that the nozzle 37 has reached the position β. The control device 60 that senses that the nozzle 37 has reached the position β sets the rotation of the motor 47 in the reverse direction so as to reverse the direction of movement of the nozzle 37 from the position β toward the position α (SP4). ). Similarly, the control device 60 repeats the control according to the control procedure shown in FIGS. 8 and 9, whereby the nozzle 37 reciprocates between the position α and the position β while the movement speed is optimally adjusted.

According to the above embodiment, when the nozzle 37 of the soot blower 30 is moved in the radial direction while injecting a gas such as steam toward the circular plane of the rotating body 21 of the rotary preheater 1, the control device 60. Thus, the nozzle 37 is sprayed onto the rotating body 21 of the rotary preheater 1 by performing control to adjust the moving speed of the nozzle 37 so as to be the optimum set speed v _set corresponding to each radial current position r. The amount of gas injected per unit area can be made optimal and uniform, and dust attached to the rotating body 21 can be reliably removed. Furthermore, it is possible to reduce the amount of gas that is wasted and to improve economy.

  As a second embodiment of the present invention, the nozzle 37 of the soot blower 30 may be reciprocated in the radial direction using the supply pipe 36 that reciprocates linearly in the radial direction. FIG. 11 is a plan view showing, as an example, a soot blower 30 provided at the tip of a supply pipe 36 that reciprocally linearly moves the nozzle 37 in the radial direction.

According to the second embodiment described above, the nozzle 37 is provided at the tip of the supply pipe 36 that performs reciprocating linear motion, and the moving direction of the nozzle 37 is matched with the radial direction. _Can be set more accurately when setting the optimum setting speed v _set according to each position r in the radial direction. The second embodiment also has the same effect as the first embodiment.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, this invention is not limited to the example which concerns. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  In the above-described embodiment, the case where the soot blower 30 according to the embodiment of the present invention is applied to the rotary air preheater 1 used in the thermal power generation facility 2 for burning coal has been described. The soot blower 30 according to the embodiment may be used for a rotary air preheater of a thermal power generation facility that generates power by burning petroleum or heavy oil, and other rotary air preheaters.

  In the above-described embodiment, the case where the soot blower 30 is provided on one or both of the circular planes on both sides of the rotating body 21 of the rotary air preheater 1 has been described, but the soot blower 30 (31) A plurality may be provided on one or both of the circular planes on both sides of the rotating body 21.

  In the above-described embodiment, the case where the soot blower 30 (31) is provided on the circular planes on both sides of the rotating body 21 of the rotary air preheater 1 has been described. , May be provided on a circular plane other than both sides.

  In the embodiment described above, the case where the gas ejected from the nozzle 37 of the soot blower 30 is steam has been described, but the gas ejected from the nozzle 37 may be a gas other than steam.

  In the above-described embodiment, the case where the supply pipe 36 of the soot blower 30 is driven by the motor 47 via the shaft 45 has been described, but the supply pipe 36 may be directly driven by the motor 47.

In the above-described embodiment, the case where the optimum set speed v _set of the nozzle 37 is calculated from the current position r in the radial direction of the nozzle 37 using the swing function shown in FIG. 10 has been described, but other methods are used. Thus, the optimum set speed v _set of the nozzle 37 may be calculated from the current position r in the radial direction of the nozzle 37.

  In the above-described embodiment, the case has been described in which the optimization is performed by making the injection amount per unit area of the gas injected to the rotating body 21 of the rotary preheater 1 uniform. The injection amount per area may be optimized without being made uniform.

  A comparison will be made between the injection amounts when dust is removed using a conventionally known soot blower and the soot blower of the present invention. The radius of the rotary body of the rotary preheater is 5.0 (m) and the rotational speed is 1.4 (rpm). The soot blower nozzle provided on one circular plane (high temperature side) of this rotary body is a steam The flow rate for injecting steam is 1.7 (ton / h), the flow rate at which the nozzle of the soot blower provided on the other circular plane (low temperature side) of the rotating body injects steam is 2.0 (ton / h), An injection time during which the low temperature side nozzle injects steam is 1 (h).

First, in the case of a conventionally known soot blower, the injection amount per unit time is constant.
Injection amount of high temperature side nozzle = 1.7 (ton / h) × 1 (h)
= 1.7 (ton / time)
Injection quantity of low temperature side nozzle = 2.0 (ton / h) × 1 (h)
= 2.0 (ton / time)
Thus, the injection amount per one time is 3.7 (ton / time) in total on the high temperature side and the low temperature side.

On the other hand, in the case of the soot blower of the present invention, the injection is performed with a constant injection amount per unit area. Note that the injection amount per unit area at this time is the minimum required value for removing dust sprayed by the nozzle of a conventionally known soot blower toward the outer peripheral portion of the rotating body. The injection amount per area is 7.1 × 10 ⁻³ (ton / m ² ), and the injection amount per unit area of the low temperature side nozzle is 8.4 × 10 ⁻³ (ton / m ² ). As a result,
Injection amount of high temperature side nozzle = 7.1 × 10 ⁻³ (ton / m ² ) × (circular plane area)
= 7.1 × 10 ⁻³ (ton / m ² ) × (π × 5.0 ² ) (m ² )
= 0.56 (ton / time)
Injection amount of low temperature side nozzle = 8.4 × 10 ⁻³ (ton / m ² ) × (circular plane area)
= 8.4 × 10 ⁻³ (ton / m ² ) × (π × 5.0 ² ) (m ² )
= 0.66 (ton / time)
Thus, the injection amount per one time is 1.22 (ton / time) in total on the high temperature side and the low temperature side.

  That is, when the soot blower of the present invention is used, dust can be removed with a steam injection amount of about 35%, compared to the case where a conventionally known soot blower is used. For example, if the number of times the soot blower is operated is 2 (times / day), for example, if the steam unit price is 3500 (yen / ton), (3.7-1.22) (ton / time) × 2 ( Time / day) x 365 (day / year) x 3500 (yen / ton) = 6336400 (yen / year) As can be seen from the calculation, the cost is reduced by about 6.3 million yen compared to the conventional soot blower. Can do.

  The present invention can be applied to, for example, a rotary air preheater of a thermal power generation facility that generates power by burning coal, but a rotary air preheater of a thermal power generation facility that generates power by burning petroleum or heavy oil, or other rotary type It is also useful for air preheaters.

Schematic diagram in the case where a nozzle that injects steam at a constant flow rate toward the lower circular surface of a rotating body that rotates at a constant speed is linearly moved in a radial direction from the outer periphery A to the center O at a constant speed. It is. It is a block diagram explaining the structure of the thermal power generation equipment provided with the rotary air preheater used for implementing embodiment of this invention. It is a perspective view which shows the simple structure of a rotary air preheater. It is a top view of the rotary air preheater provided with the soot blower which concerns on embodiment of this invention. It is the side view which looked at the rotary air preheater of Drawing 4 toward the X direction. It is the side view which looked at the rotary air preheater of FIG. 4 toward the Y direction. It is the top view to which the main body of the soot blower was expanded. It is a whole flowchart which shows the procedure of the control method of the soot blower which concerns on embodiment of this invention. In FIG. 8, it is a flowchart which shows the detailed control procedure at the time of controlling a motor so that the moving speed of a nozzle may be controlled based on the present position of the radial direction of a nozzle. It is a diagram showing the swing function indicating the relationship between the position r and the optimum set speed v _{The set} of radial nozzles used to calculate the current position r from the optimum set speed v _{The set} of nozzles in the radial direction of the nozzle . It is the top view which showed the soot blower which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating air preheater 2 Thermal power generation equipment 3 Boiler 4 Turbine / generator 5 Steam pipe 6 Coal bunker 7 Crusher 10 Air supply pipe 11 Exhaust gas exhaust pipe 12 Pushing fan 13 Chimney 14 Induction fan 15 Denitration device 16 Electric dust collector 20 Casing DESCRIPTION OF SYMBOLS 21 Rotating body 22 Rotor 23 Partition 24, 25 Semi-cylindrical space 30, 31 Soot blower 35 Main body of soot blower 36 Supply pipe 37 Nozzle 40 Support body 41 Rotating shaft 42 Lever 43 Housing 45 Shaft 46 Pin 47 Motor 48, 49 Bevel gear 50 , 51 sensors a, B, C, O radial position of the nozzle N nozzles R rotator center X of the circular plane of the outer peripheral portion S ₂ rotator circular plane of the circular plane S ₁ rotator of radius S rotator , Y, Z direction r Nozzle radial position t Predetermined time α, β Nozzle position α ', β' lever position

Claims (9)

A soot blower for removing the dust attached to a cylindrical rotating body provided in a rotary air preheater that exchanges heat between exhaust gas containing dust and air,
A nozzle for injecting gas toward a circular plane of the rotating body;
A diameter between the first position for injecting gas toward the center of the circular plane of the rotating body and the second position for injecting gas toward the outer periphery of the circular plane of the rotating body. A drive mechanism that reciprocates in the direction;
A sensor capable of sensing that the nozzle has reached the first position or the second position;
A control device for controlling the drive mechanism;
The control device controls the driving mechanism so that the nozzle moves at a predetermined moving speed according to a radial position, and the nozzle is moved to the first position or the second position by the sensor. The soot blower is characterized by controlling the drive mechanism so as to reverse the direction of movement of the nozzle when it is sensed that the nozzle reaches the position. The predetermined moving speed is set so that an injection amount per unit area of gas injected by the nozzle toward the circular plane of the rotating body is uniform on the circular plane of the rotating body. The soot blower according to claim 1, characterized in that it is characterized in that 3. The soot blower according to claim 1, wherein the nozzle, the drive mechanism, the sensor, and the control device are provided for one or both of the circular planes on both sides of the rotating body. The rotary air preheater includes a semi-cylindrical exhaust gas side passage and a semi-cylindrical air side passage, and the rotating body is disposed across the exhaust gas side passage and the air side passage. The soot blower according to any one of claims 1 to 3. The soot blower according to claim 4, wherein the nozzle is provided in the exhaust gas side passage. A soot blower control method for ejecting gas from a nozzle to remove dust attached to a cylindrical rotating body provided in a rotary air preheater that exchanges heat between exhaust gas containing dust and air,
Rotating the rotating body at a constant rotational speed;
While injecting a constant flow of gas from the nozzle onto the circular plane of the rotating body,
The nozzle is reciprocated in a radial direction between a first position for injecting gas toward the center of the circular plane and a second position for injecting gas toward the outer periphery of the circular plane; In the reciprocal movement, the soot blower control method is characterized in that the nozzle is moved at a predetermined moving speed according to a radial position. The predetermined moving speed is set so that an injection amount per unit area of gas injected by the nozzle toward the circular plane of the rotating body is uniform on the circular plane of the rotating body. The method for controlling a soot blower according to claim 6, wherein the soot blower is controlled. The soot blower control method according to claim 6 or 7, wherein the radial position of the nozzle is calculated as a moving distance of the nozzle from the first position or the second position. The soot blower control method according to claim 8, wherein the calculated movement distance is initialized when the nozzle reaches the first position or the second position.

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