JP5159856B2 - Electric dust collection system and electric dust collection method - Google Patents

Description

  The present invention relates to an electrostatic precipitator that is provided in a ventilation system of an exhaust gas treatment system for coal-fired power and removes soot in exhaust gas (hereinafter simply referred to as exhaust gas), and an electrostatic precipitator system that can be applied to a control method thereof. The present invention relates to an electric dust collection method.

  Conventionally, coal-fired boiler systems that burn coal, generate high-pressure steam, drive a steam turbine, rotate a generator, generate electricity, and supply electricity to consumers doing. This type of coal-fired power plant is equipped with an exhaust gas treatment system for treating exhaust gas (see Patent Document 1).

<Overall configuration example of ventilation system of coal-fired exhaust gas treatment system>
FIG. 14 is applicable to an electric dust collector that is provided in a ventilation system of an exhaust gas treatment system for fired coal fired power according to a conventional example and removes soot in exhaust gas (hereinafter simply referred to as exhaust gas) and a control method thereof. The present invention relates to an electric dust collection system and an electric dust collection method. It is a block diagram which shows the schematic structural example of the ventilation system of a power plant. According to the ventilation system of the thermal power plant shown in FIG. 14, a so-called balanced ventilation boiler system is provided, which is generally used in a coal-fired thermal power plant.

  The ventilation system of the thermal power plant includes an air preheater 11 (abbreviated as AH in FIG. 14) and an exhaust gas denitration device 13 connected to the furnace 12, and a forced air ventilator 10 (abbreviated as FDF in the figure). , Heat recovery device 14 (abbreviated as GGH in the figure), electrostatic precipitator 15 (abbreviated as EP in the figure), induction fan 30 (abbreviated as IDF in the figure), exhaust gas desulfurizer 32, A heater 35 and a chimney 40 are included.

  The furnace 12 is provided with a coal-fired boiler system (not shown). In this boiler system, combustion is performed in a state where the pressure in the furnace 12 is slightly lower than the atmospheric pressure. An exhaust gas denitration device 13 is connected to the furnace 12 via a flue (not shown). The exhaust gas denitration device 13 removes nitrogen oxides from the exhaust gas.

  An air preheater 11 is connected to the exhaust gas denitration device 13 via a flue. The air preheater 11 performs heat exchange between the combustion gas that has passed through the exhaust gas denitration device 13 from the furnace 12 and the combustion air, and heats the air. The heated combustion air is burned together with coal fuel in the furnace 12 to become exhaust gas. The forced air blower 10 is connected to the air preheater 11 through an air duct (not shown). The forced air blower 10 sucks combustion air from the boiler top and supplies it to the inside of the furnace 12.

  A heat recovery device 14 is connected to the air preheater 11 via a flue. The heat recovery unit 14 exchanges heat between the exhaust gas and the untreated gas so as to absorb heat from the exhaust gas. An electric dust collector 15 (Electrostatic Precipitator: hereinafter simply referred to as EP) is connected to the heat recovery unit 14 via a flue. The electric dust collector 15 removes soot and dust from the exhaust gas that has passed through the heat recovery device 14. The electrostatic precipitator 15 generates a corona discharge by a DC high voltage, charges dust in the gas (discharge electrode), passes the charged particles in the electric field (between the electrodes), and separates it from the gas. It will be collected (dust collecting electrode).

  An induction ventilator 30 is connected to the outlet flue 21 (see FIG. 15) of the electric dust collector 15. Since the induction fan 30 controls the pressure inside the furnace 12, the exhaust gas from the electrostatic precipitator 15 from which the dust is removed is sucked and sent to the exhaust gas desulfurization device 32, and released from the chimney 40 to the atmosphere. Made. An exhaust gas desulfurization device 32 is connected to the induction fan 30 via a flue. The exhaust gas desulfurizer 32 removes sulfur oxide from the exhaust gas.

  A reheater 35 is connected to the exhaust gas desulfurization device 32 through a flue. The reheater 35 exchanges heat between the high-temperature untreated gas from the heat recovery unit 14 and the exhaust gas after removing the sulfur oxide, and raises the temperature of the exhaust gas to a predetermined temperature. A chimney 40 is connected to the reheater 35 via a flue. The chimney 40 releases the exhaust gas introduced through the reheater 35 and the booster (not shown) to the atmosphere.

  Thus, according to the ventilation system of the thermal power plant equipped with the balanced ventilation boiler system, the air boosted by the forced air blower 10 is supplied to the furnace 12 and the exhaust gas is drawn from the furnace 12 by the induction fan 30. Therefore, it is operated while keeping the inside of the furnace 12 at a negative pressure. Thereby, it is suppressing that exhaust gas and combustion ash leak from the furnace 12 to the atmosphere.

  By the way, for example, a centrifugal fan or an axial fan is used for the pusher fan 10 or the induction fan 30, but the inlet pressure of the induction fan 30 varies depending on the opening degree of the moving blade (not shown). To do. The blade opening of the induction fan 30 varies depending on the blade opening of the forced air blower 10, that is, the amount of combustion air pushed into the furnace 12, and is controlled to keep the furnace pressure constant. Because. When the air density in summer is low, the moving blade opening of the forced air blower 10 increases, and the moving blade opening of the induction fan 30 also increases accordingly. At this time, if the damper of the electrostatic precipitator 15 is closed, the electrostatic precipitator 15 becomes a resistance, so that the moving blade opening of the induction fan 30 is further increased and the input pressure is also increased. When the blade opening degree of the induction fan 30 exceeds the control range, the furnace pressure control becomes impossible.

<Configuration example of the electric dust collector 15>
Next, a configuration example of the electrostatic precipitator 15 will be described with reference to FIG. The electrostatic precipitator 15 shown in FIG. 15 has a case 15a and a partition plate 15b having a predetermined shape.
The partition plate 15b is disposed in the case 15a in a direction along the flow of exhaust gas (hereinafter referred to as a gas flow direction), and the interior of the case 15a is divided into a first chamber 16 and a second chamber 17 by the partition plate 15b. . The inlets of the first chamber 16 and the second chamber 17 are connected to the inlet flue 18 and the outlet thereof is connected to the outlet flue 21.

  Further, the first chamber 16 and the second chamber 17 are divided (divided) into three sections 1S to 3S by a virtual plane (a plane perpendicular to the gas flow direction) orthogonal to the gas flow direction. The inside of the case 15a is divided into six sections by the three sections 1S to 3S and the partition plate 15b. The first chamber 16 is divided into three compartments 16a to 16c by sections 1S to 3S, and the compartments 16a to 16c correspond to the front chamber, the intermediate chamber, and the rear chamber from the upstream side to the downstream side in the gas flow direction. ing. Similarly, the second chamber 17 is divided into three compartments 17a to 17c, and the compartments 17a to 17c correspond to the front chamber, the intermediate chamber, and the rear chamber.

  Each of the compartments 16a, 16b, 16c, 17a, 17b, and 17c is independently provided with a dust collecting electrode 1 and a discharge electrode 2, a dust collecting electrode striking device 24a, 24b, 24c, 25a, 25b, and 25c described later, and a charge. Have units. The inlet flues 18 of the first chamber 16 and the second chamber 17 are provided with inlet dampers 19 and 20 that can be opened and closed independently. The exit flues 21 of the first chamber 16 and the second chamber 17 are respectively provided with exit dampers 22 and 23 that can be opened and closed independently. The inlet damper 19 and the outlet damper 22 are gradually opened and closed over a predetermined time.

  According to the electrostatic precipitator 15, when the inlet damper 19 and the outlet damper 22 of the first chamber 16 are fully closed, the exhaust gas does not flow from the inlet flue 18 of the first chamber 16, and from the outlet flue 21. There is no spillage. When the inlet damper 20 and the outlet damper 23 of the second chamber 17 are fully opened, the exhaust gas flows from the inlet flue 18 of the second chamber 17 and flows out from the outlet flue 21. Thus, the flow of the exhaust gas in the electrostatic precipitator 15 is controlled by opening / closing control of the inlet dampers 19 and 20 and the outlet dampers 22 and 23.

  In the electrostatic precipitator 15, exhaust gas containing soot passes through the inlet flue 18, and after the flow velocity distribution is uniformed by a baffle plate (not shown), the exhaust gas flows between the dust collection electrode 1 and the discharge electrode 2. Are introduced into the electric field (corona discharge). The dust in the exhaust gas is attracted to the dust collection electrode 1 by the electrostatic force (Coulomb force) of the electric field generated by the discharge electrode 2 and collected.

  The dust collecting electrode 1 of each of the compartments 16a, 16b, 16c, 17a, 17b, 17c is configured to be beaten by dust collecting beating devices 24a, 24b, 24c, 25a, 25b, 25c, respectively. After the dust dust is peeled off from the surface of the dust collecting electrode 1 by the impact force of the hammering by the dust collecting electrode hammering devices 24a, 24b, 24c, 25a, 25b, and 25c, and dropped on the hopper (see FIG. 1). , It is configured to collect dust. The electric dust collector 15 can perform a damper opening and closing operation.

<Example of operation when opening a damper>
With reference to FIGS. 16A to 16D, a control method at the time of opening the damper in the electrostatic precipitator 15 will be described by taking the first chamber 16 as an example. When the electric dust collector 15 is in operation, for example, soot is gradually accumulated on the dust collecting electrode 1 of the first chamber 16.

  Therefore, according to the control method at the time of opening the damper, the predetermined operating time shown in FIGS. 16A and 16B, the inlet damper 19 and the outlet damper 22 are fully opened, and the predetermined operating time shown in FIG. In the ON state, the dust collecting electrodes in the compartment 16a (front chamber) and the compartment 16b (intermediate chamber) of the first chamber 16 by the operating time shown in FIG. 16C and the dust collector striking devices 24a and 24b. It is made to strike one. The full opening operation of the inlet damper 19 and the outlet damper 22 is to suppress draft fluctuation due to opening and closing of the moving blade (not shown) of the induction fan 30.

<Example of operation when the damper is closed>
Next, with reference to FIGS. 17A to 17D, a control method at the time of closing the damper in the electrostatic precipitator 15 will be described by taking the first chamber 16 as an example. According to the control method at the time of closing the damper, the inlet damper 19 and the outlet damper 22 of the first chamber 16 shown in FIG. It is fully closed at the timing of, and the flow of exhaust gas is temporarily interrupted.

  While the flow of the exhaust gas is interrupted, the dust collecting electrode striking devices 24a, 24b, 24c remove the dust collecting electrode 1 in the compartments 16a, 16b, 16c at the predetermined timing shown in FIG. 17C. Hit. At this time, the dust collecting electrode 1 is in an uncharged (charged OFF) state (damper closing strike). Further, after the dust collector electrode 1 is closed and closed, the electrostatic precipitator 15 is charged (charged ON) at a predetermined timing shown in FIG. 17D, and after a predetermined sedation time has elapsed, the inlet damper 19 and The exit damper 22 is fully opened.

  That is, the dust is peeled off from the surface of the dust collecting electrode 1 by the impact force of the striking by the dust collecting electrode striking devices 24a, 24b, 24c, and dropped on the hopper (not shown) and collected by this. The dust scattered by the beating is collected by charging ON of the electrostatic precipitator 15, and then the entrance damper 19 and the exit damper 22 are fully opened, so that the dust is re-scattered and flows out from the exit flue 21. Can be suppressed.

  In the coal-fired boiler system, four electrostatic precipitators 15 are provided, and the time required for closing the damper is about 30 minutes per room of the electrostatic precipitator 15. Therefore, it takes about 1 hour per damper to hit the damper, and about 4 hours for the entire system. Therefore, in one electrostatic precipitator 15, the beat is repeated by the timer for about 30 minutes every 4 hours. The discharge electrode 2 is beaten with the inlet damper 19 and the outlet damper 22 being opened regardless of the method of beating the dust collecting electrode 1 (Patent Document 2).

Japanese Patent Laid-Open No. 06-114288 (page 2 Fig. 1) Japanese Patent Laying-Open No. 2010-022907 (FIG. 2 on page 7)

  By the way, according to the electrostatic precipitator 15 according to the conventional example as seen in Patent Documents 1 and 2, whether the operating condition of the coal-fired boiler system corresponds to the damper opening condition or the damper closing condition. When the operation condition of this boiler system corresponds to the damper closing strike condition, the inlet damper 19 and the outlet damper 22 are closed and in the non-charged state, the compartments 16a, 16b and 16c The dust collecting electrode 1 is beaten. After the control of the first chamber 16, the second chamber 17 is similarly controlled, and these controls are repeatedly performed every predetermined time.

  When the operating condition of the coal-fired boiler system is, for example, the moving blade opening at the inlet of the induction fan becomes greater than or equal to a predetermined value during the daytime in summer, the damper opening is performed. According to the damper opening hammering, in the first chamber 16, the dust collecting electrode 1 in the compartments 16a and 16b is hammered while the inlet damper 19 and the outlet damper 22 are opened and charged. As described above, the operation method of the electrostatic precipitator 15 is the regular (main) damper closing and the damper opening and closing operation is selected according to the operation status of the ventilation system. For this reason, not only the power cost (ventilation loss) of the ventilation system during normal operation has not been reduced, but also the coal-fired boiler system is not being operated efficiently.

  Therefore, the present invention solves such a problem, and improves the EP strike control system for controlling the damper open strike and damper close strike to reduce the power cost of the ventilation system during normal operation. An object of the present invention is to provide an electric dust collection system and an electric dust collection method capable of efficiently operating a coal-fired boiler system.

In order to solve the above-described problem, an electric dust collection system according to claim 1 is an equilibrium ventilation system having a forced draft fan for sending combustion air into a furnace and an induction draft fan for controlling the pressure in the furnace. In order to remove the dust in the exhaust gas from the furnace, the interior of the case is divided into a plurality of compartments, each of which can be independently charged, and each compartment A dust collecting electrode provided to collect the dust, an inlet damper provided in an inlet flue of the case to control the flow of the exhaust gas, an outlet damper provided in an outlet flue, and the dust collecting An electric dust collection system comprising a dust collection electrode striking device for striking a pole, wherein the inlet damper and the outlet damper are in an open state, and the dust collection electrode is charged and the dust collection electrode is charged. Intermittent strike against dust electrode The repeated operation is an interval charge strike, and the entrance damper and the exit damper are closed, and the dust collection electrode is uncharged and strikes the dust collection electrode in the compartment a predetermined number of times. When the operation to perform is a damper-linked non-charged strike, the operation mode for the strike mode selection for selecting either the interval charge strike or the damper-linked uncharged strike, and the operating conditions of the boiler system A detecting unit for detecting, a control unit for controlling the dust collecting and striking device based on operating conditions of the boiler system obtained from the detecting unit, and a concentration for detecting the concentration of soot in the exhaust gas discharged from the furnace a detecting unit, configured and a ash processing apparatus for processing a dust discharged from each of said compartments, said controller, normally the interval charged hammering by the selection by the operation unit The dust collecting striker is controlled so as to perform, and it is determined whether or not the operation condition of the boiler system corresponds to the interval charge strike condition during the execution of the interval charge strike. Based on this, the dust collecting striking device is controlled so as to perform the damper-linked non-charged striking , and further, the dust concentration value based on the dust concentration information obtained from the concentration detecting unit and the striking method are determined. When the dust concentration value is less than or equal to the discrimination reference value, the dust collecting striking device is controlled so that the interval charge strike is always performed, and the dust concentration value is discriminated. If the reference value is exceeded, the dust collecting electrode striking device is controlled to perform the damper-linked non-charged striking, and further, the dust ash processing time processed by the ash processing device, and the striking method Discriminant reference value to determine When the ash treatment time is equal to or less than the determination reference value, the dust collecting electrode striking device is controlled so that the interval charge striking is always performed .

According to the electric dust collection system of the present invention, the compartment, the dust collecting electrode, the inlet damper, the outlet damper, the dust collecting pole striking device, the operation unit for selecting the striking mode, the detecting unit , the concentration detecting unit, the ash treatment A device and a control device. The operation unit is operated so as to select either the interval charge strike or the damper-linked non-charge strike. The detection unit detects operating conditions of the boiler system. The control device controls the dust collecting pole striking device based on the operating conditions of the boiler system obtained from the detection unit. The concentration detector detects the concentration of soot in the exhaust gas discharged from the furnace. The ash treatment device treats the dust discharged from each compartment. These on the assumption, control unit, the selection by the operation unit, and controls the dust collecting Gokutsuchi punching device so as to implement the interval charged hammering always the boiler system in the practice of the interval charged hammering operation conditions Is determined to satisfy the interval charge striking condition, and based on the determination result, the dust collecting striking device is controlled so that the damper-linked non-charge striking is performed . Further, the control device compares the dust concentration value based on the dust concentration information obtained from the concentration detection unit with the determination reference value for determining the strike method, and if the dust concentration value is equal to or less than the determination reference value, The dust collector strike device is controlled so that the charged strike is always performed. When the dust concentration value exceeds the discrimination reference value, the dust collecting pole striking device is controlled so that the damper-linked non-charge striking is performed. Further, the control device compares the ash processing time of the dust processed by the ash processing device with the determination reference value for determining the striking method, and if the ash processing time is less than the determination reference value, the interval charge soot The dust collecting and punching device is controlled so as to always perform the striking .

  When the dust collecting electrode striking device is controlled so that this interval charge striking is always performed, the dust collecting electrode in the compartment with the inlet and outlet dampers opened and the dust collecting electrode charged. Since the dust is removed so as to intermittently repeat the beating, the power consumption related to the ventilation loss (hereinafter also referred to as draft loss) can be omitted as compared with the damper-linked non-charged beating. Moreover, even if the power consumption associated with the dust collection electrode charging is subtracted from the power consumption related to the draft loss, the in-house power related to the electric dust collection system can be reduced.

  In addition, when the dust collecting electrode striking device is controlled so as to perform damper-linked non-charged striking, the inlet damper and the outlet damper are closed, and the dust collecting electrode is uncharged and the compartment Since the strike is performed a predetermined number of times with respect to the dust collecting electrode, the draft cleaning effect of the dust collecting electrode can be enhanced as compared with the interval charge strike, although it involves the draft fluctuation of the furnace. In this way, the interval charge strike can be executed mainly during normal operation, and the damper-linked non-charge strike can be executed as necessary.

According to a second aspect of the present invention, there is provided the electric dust collection system according to the first aspect , wherein the control device performs the damper-linked non-charge strike when the ash treatment time exceeds a determination reference value. The hitting device is controlled.

According to a third aspect of the present invention, there is provided an electric dust collection system according to the first or second aspect , wherein a time input unit for inputting a start time and an end time for performing the damper-linked non-charge strike, and no interval charge strike or damper-linked operation. A time output unit that outputs time information indicating the current time when the charge strike is performed, and the interval charge other than the operation set time for performing the damper-linked non-charge strike input by the time input unit. In the case of performing a strike, the control device inputs time information indicating the current time when the interval charge strike is being implemented from the time output unit, and the damper interlocked from the time input unit. Enter the start time for carrying out the non-charged strike, and enter the current time when the interval charge strike is carried out and the start time for carrying out the damper-linked non-charge strike In contrast, when the current time and the start time coincide with each other, the dust collecting pole striking device is controlled to start the damper-linked non-charge striking while continuing the interval charge striking. It is characterized by.

According to a fourth aspect of the present invention, there is provided the electric dust collection system according to the third aspect , wherein the time input unit is input with a first operation set time for performing most of the interval charge strike for one day, and the damper is not linked. A second operation set time for performing charge strike at night is input, and the control device performs interval charge strike based on the first operation set time output from the time input unit. And controlling the dust collecting pole striking device so that the damper-linked non-charge striking is performed at night based on the second operation setting time. To do.

The electric dust collection method according to claim 5 is installed in a ventilation system of a balanced ventilation type boiler system having a forced draft fan for sending combustion air into the furnace and an induction draft fan for controlling the pressure in the furnace. In order to remove the dust in the exhaust gas from the furnace, the inside of the case is divided into a plurality of compartments, each of which can be independently charged, and a collection chamber for collecting the dust provided in each compartment. A dust electrode, an inlet damper provided in an inlet flue of the case to control the flow of the exhaust gas, an outlet damper provided in an outlet flue, and a dust collecting electrode for striking the dust collecting electrode electrostatic precipitator system comprising a striking device, comprising the steps of: detecting an operating condition of the boiler system, and controlling the dust collector Gokutsuchi hitting device based on the operating conditions of the detection by said boiler system Including and running the entrance An operation that repeats striking intermittently with respect to the dust collecting electrode of the compartment with the dust collecting electrode in a charged state while the damper and the outlet damper are open is referred to as interval charging striking, and the inlet damper In addition, the operation that strikes the dust collecting electrode in the compartment a predetermined number of times in a state where the outlet damper is closed and the dust collecting electrode is in an uncharged state is referred to as a damper-linked uncharged striking. A step operated to select one of the interval charge strike and the damper-linked non-charge strike, and the dust collecting electrode strike device so as to always carry out the selected interval charge strike. A step of determining whether or not an operating condition of the boiler system corresponds to an interval charge strike condition during execution of the interval charge strike, and Run and controlling the dust collector Gokutsuchi punching device to perform the damper interlocking uncharged hammering, further, dust concentration based on dust concentration information indicating the concentration of dust in exhaust gas discharged from the furnace Comparing the value with a discrimination reference value for determining a striking method, and, if the dust concentration value is equal to or less than the discrimination reference value, the dust collecting pole strike so that the interval charge strike is always performed. Controlling the apparatus, and if the dust concentration value exceeds a discrimination reference value, executing the step of controlling the dust collecting electrode striking device to perform the damper-linked non-charged striking, Comparing the ash treatment time of the dust discharged from each of the compartments with a discrimination reference value for determining a striking method; and when the ash treatment time is equal to or less than the discrimination reference value, the interval charge soot Always hitting And a step of controlling the dust collecting pole striking device so as to be applied.

According to the electric dust collection system and the electric dust collection method of the present invention, the electric dust collection system and the electric dust collection method are provided with a control device that controls the dust collection electrode striking device based on the operating condition of the boiler system. The dust collecting striker is controlled so as to perform, and it is determined whether or not the operation condition of the boiler system corresponds to the interval charge strike condition during the execution of the interval charge strike. And control the dust collecting striker so that the damper-linked uncharged strike is performed . Further, the control device compares the dust concentration value based on the dust concentration information obtained from the concentration detection unit with the determination reference value for determining the strike method, and if the dust concentration value is equal to or less than the determination reference value, The dust collector strike device is controlled so that the charged strike is always performed. When the dust concentration value exceeds the discrimination reference value, the dust collecting pole striking device is controlled so that the damper-linked non-charge striking is performed. Further, the control device compares the ash processing time of the dust processed by the ash processing device with the determination reference value for determining the striking method, and if the ash processing time is less than the determination reference value, the interval charge soot The dust collecting and punching device is controlled so that the hitting is always performed .

  With this configuration, when the dust collecting electrode striking device is controlled so that interval charge striking is always performed, the dust collecting electrode is charged with the inlet and outlet dampers open, and the dust collecting electrode in the compartment is charged. Since dust is removed so as to intermittently strike the pole, it is possible to omit the power consumption related to the draft loss as compared with the damper-linked non-charged strike. Moreover, even if the power consumption associated with the dust collection electrode charging is subtracted from the power consumption related to the draft loss, the in-house power related to the electric dust collection system can be reduced.

  In addition, when the dust collecting electrode striking device is controlled so as to perform damper-linked non-charged striking, the dust collecting electrode in the compartment with the inlet and outlet dampers closed and the dust collecting electrode uncharged. Although the strike is performed a predetermined number of times with respect to the pole, and the draft fluctuation of the furnace is accompanied, the dust cleaning effect of the dust collecting electrode can be enhanced as compared with the interval charge strike. As a result, the power cost of the ventilation system during normal operation can be reduced, the cost of the coal-fired boiler system can be reduced, and the system can be operated efficiently.

It is a block diagram which shows the example of schematic structure of the control system of the electric dust collection system 100 as embodiment which concerns on this invention. It is the schematic which shows the structural example of the ventilation system in the electric dust collector. It is the schematic which shows the example of control at the time of interval charge strike. It is the schematic which shows the control example (the 1) at the time of a damper interlocking non-charge strike. It is the schematic which shows the control example (the 2) at the time of a damper interlocking non-charging strike. It is the schematic which shows the control example (the 3) at the time of damper interlock | cooperating non-charge strike. It is the schematic which shows the control example (the 4) at the time of a damper interlocking non-charging strike. It is the schematic which shows the example of control (the 5) at the time of a damper interlocking non-charge strike. It is the schematic which shows the control example (the 6) at the time of damper interlocking non-charging strike. It is the schematic which shows the control example (the 7) at the time of a damper interlocking non-charging strike. It is the schematic which shows the control example (the 8) at the time of a damper interlocking non-charge strike. 5 is a flowchart showing an example of control of the electric dust collector 15. It is a table | surface figure which shows the comparative example of IDF power cost in the electric dust collection system. It is a block diagram which shows the schematic structural example of the ventilation system of the thermal power plant which concerns on a prior art example. 4 is a plan sectional view showing a schematic configuration example of the electrostatic precipitator 15. FIG. (A)-(D) are time charts which show the example of a control at the time of damper opening hammering. (A)-(D) is a time chart which shows the example of control at the time of damper closing hitting.

  Hereinafter, an electric dust collection system and an electric dust collection method according to the present invention will be described with reference to the drawings. An electric dust collection system 100 shown in FIG. 1 is applicable to a coal-fired boiler system and is installed in a ventilation system of a balanced ventilation boiler system so as to remove dust in exhaust gas from the furnace 12. Function. The electric dust collection system 100 includes an electric dust collection device 15, an EP ash treatment device 42, a damper drive device 43, a dust concentration detection device 44, an operation unit 54, and a control device 55.

  As the electrostatic precipitator 15, the same structure as that of the electrostatic precipitator 15 described in the prior art is used. Therefore, in the following description, the same members as those already described are denoted by the same reference numerals, and redundant description is omitted. In this embodiment, when the control device 55 controls the electrostatic precipitator 15 based on the operating conditions of the coal-fired boiler system, the interval charge strike is mainly executed during normal operation, and as necessary. The damper-linked uncharged strike can be executed.

  Here, the interval charge strike is a state in which the entrance dampers 19 and 20 and the exit dampers 22 and 23 described with reference to FIG. 15 are opened, and the dust collection electrode 1 is charged and the compartments 16a, 16b, and 16c are collected. An operation that intermittently strikes the dust electrode 1 (corresponding to a damper opening strike). The damper-linked non-charged striking means that the inlet dampers 19 and 20 and the outlet dampers 22 and 23 are closed and the dust collecting electrode 1 is uncharged to the dust collecting electrodes 1 of the compartments 16a, 16b and 16c. The operation of hitting a predetermined number of times (corresponding to a damper closing strike).

  The EP ash treatment device 42 takes in the dust discharged from each compartment 16a, 16b, 16c of the electric dust collector 15 through the hopper 41, processes the dust based on the ash treatment control signal S42, and forms gypsum. A predetermined ash treatment time (hereinafter referred to as an EP ash treatment time) is required to make gypsum into gypsum. The EP ash treatment device 42 is connected to the control device 55 and outputs EP ash treatment information D42 indicating the EP ash treatment time to the control device 55. The ash processing control signal S42 is output from the control device 55 to the EP ash processing device 42.

  The damper driving device 43 drives the inlet dampers 19 and 20 and the outlet dampers 22 and 23 based on the damper driving information D43. The damper driving device 43 is connected to the control device 55. The damper drive information D43 is output from the control device 55 to the damper drive device 43. The damper driving device 43 decodes the damper driving information D43 and generates damper control signals S19, S20, S22, and S23.

  The damper control signal S19 is output from the damper driving device 43 to a motor (not shown) that drives the inlet damper 19. The damper control signal S20 is output from the damper driving device 43 to a motor (not shown) that drives the inlet damper 20. The damper control signal S22 is output from the damper driving device 43 to a motor (not shown) that drives the outlet damper 22. The damper control signal S23 is output from the damper driving device 43 to a motor (not shown) that drives the outlet damper 23.

  The dust concentration detection device 44 constitutes an example of a detection unit and detects the operating conditions of the coal-fired boiler system. The soot concentration detection device 44 is connected to the control device 55 and detects the concentration of soot in the exhaust gas discharged from the furnace 12. The measurement point is, for example, in the vicinity of the exit flue 21 and is a position where the dust concentration of the exhaust gas after the dust removal can be detected. A dust concentration detection sensor (not shown) is disposed at this position, and a dust concentration detection signal S44 is output from the dust concentration detection sensor to the dust concentration detection device 44.

  The dust concentration detection device 44 outputs dust concentration information D44 after analog / digital conversion of the dust concentration detection signal S44 to the control device 55. Of course, a measurement point is provided in the vicinity of the inlet flue 18 or downstream of the induction fan 30 to detect the dust concentration of the exhaust gas after removal of the dust discharged therefrom, and output the dust concentration information to the control device 55. You may make it do.

  The controller 55 is connected to an operation unit 54 for selecting a beating mode, and is operated in the electric dust collection system 100 so as to select either an interval charge beating or a damper-linked non-charge beating. The operation unit 54 includes an operation selection display unit 56, a strike selection display unit 57, and four selection buttons 54a to 54d.

  The operation selection display unit 56 is a display that displays a selection of whether to operate the electrostatic precipitator 15 in the automatic mode or the manual mode. Below the operation selection display section 56, an automatic mode selection button 54a and a manual mode selection button 54b are arranged. The selection button 54a is pressed when the electric dust collector 15 is automatically operated (automatic mode selection). The selection button 54b is pressed when manually operating the electrostatic precipitator 15 (manual mode selection).

  The striking selection display unit 57 is a display that displays whether to select interval operation (damper-open charge striking) or damper-linked operation (damper-closed non-charge striking) in the electric dust collector 15. Below the strike selection display portion 57, an interval operation selection button 54c and a damper-linked operation selection button 54d are arranged. The selection button 54 c is pressed when selecting the interval operation in the electric dust collector 15. The selection button 54d is pressed when the damper operation is selected in the electric dust collector 15.

  The operation unit 54 also serves as a time input unit, and is provided with a numeric keypad such as numerals 0 to 9 (not shown), and is operated to input a start time and an end time for performing the damper-linked non-charge strike. The above-described start time and end time are operation setting times for the damper-linked non-charge strike. In this example, the interval charge beating is performed except for the operation set time in which the damper-linked non-charge beating input by the operation unit 54 is performed. The operation unit 54 outputs, to the control device 55, operation information D54 obtained by the above-described operation and indicating the automatic mode or manual mode, interval operation or damper-linked operation, operation set time, and the like.

  When such an operation unit 54 is provided, the interval charge beating set in the summer daytime when using the air conditioner, the concentration of soot in the exhaust gas discharged from the furnace 12, the compartments 16a, 16b, 16c, etc. Based on the EP ash treatment time or the like for treating the dust discharged from the vehicle, for example, at night, it can be switched to a damper-linked non-charged strike.

  A monitor 58 is connected to the control device 55. The monitor 58 displays a ventilation screen, a schedule screen such as interval operation or damper-linked operation, operation set time, and the like. Of course, it is not limited to the schedule screen. For example, IDF measurement time [h] vs. IDF motor current [A], EP current [A], etc. when comparing IDF power costs as shown in FIG. 13 may be displayed. The schedule screen or the like is displayed based on display information D58 output from the control device 55 to the monitor 58.

  The control device 55 is provided with a timer 52 as an example of a time output unit in addition to the memory 51 and the CPU 53. The timer 52 outputs to the CPU 53 time information indicating the current time when the interval charge strike or the damper-linked non-charge strike is performed. The memory 51 stores information input at the time of initial setting, for example, schedule information related to operation setting time for interval charge strike or damper-linked non-charge strike.

  Further, the control device 55 controls the dust collecting and hammering devices 24a, 24b, 24c, 25a, 25b and 25c based on the operating conditions of the coal fired boiler system obtained from the dust concentration detector 44. For example, the control device 55 controls the dust collecting electrode striking devices 24a, 24b, 24c, 25a, 25b, and 25c so that the interval charge striking operation is always and actively performed, and during the interval charge striking operation. It is determined whether or not the operating condition of the boiler system corresponds to the interval charge striking condition. If the operating condition of the coal fired boiler system does not correspond to the interval charge striking condition, an exception is linked to the damper. The dust collecting pole strikers 24a, 24b, 24c, 25a, 25b, and 25c are controlled so as to perform uncharged strikes.

  In this example, the control device 55 compares the dust concentration value based on the dust concentration information obtained from the dust concentration detection device 44 with the determination reference value for determining the hitting method, and the dust concentration value is equal to or less than the determination reference value. In some cases, the dust collector striking devices 24a, 24b, 24c, 25a, 25b, and 25c are controlled so as to perform interval charge striking. With this control, the inlet dampers 19 and 20 and the outlet dampers 22 and 23 are opened and the dust collecting electrode 1 is in a charged state without the draft fluctuation of the furnace 12 during the summer daytime when using the cooling. It becomes possible to remove dust so as to intermittently strike the dust collecting electrode 1 such as the compartments 16a, 16b and 16c.

  When the dust concentration value described above exceeds the discrimination reference value, the control device 55 controls the dust collecting electrode striking devices 24a, 24b, 24c, 25a, 25b, and 25c so as to perform damper-linked non-charged striking. By this control, the compartments 16a, 16b, 16c, etc. can be used with the inlet dampers 19, 20 and the outlet dampers 22, 23 closed and the dust collecting electrode 1 in an uncharged state at night in the summer when cooling is used. By striking the dust collecting electrode 1 a predetermined number of times, the draft of the furnace 12 is fluctuated, but the dust cleaning effect of the dust collecting electrode 1 can be enhanced as compared with the interval charge striking.

  In this example, the control device 55 compares the EP ash processing time of the dust processed by the EP ash processing device 42 with the determination reference value for determining the striking method, and the EP ash processing time is less than the determination reference value. In some cases, the dust collector striking devices 24a, 24b, 24c, 25a, 25b, and 25c are controlled so as to perform interval charge striking. With this control, the inlet dampers 19 and 20 and the outlet dampers 22 and 23 are opened and the dust collecting electrode 1 is in a charged state without the draft fluctuation of the furnace 12 during the summer daytime when using the cooling. It becomes possible to remove dust so as to intermittently strike the dust collecting electrode 1 such as the compartments 16a, 16b and 16c.

  When the above-mentioned EP ash treatment time exceeds the discrimination reference value, the control device 55 controls the dust collecting electrode striking devices 24a, 24b, 24c, 25a, 25b, and 25c so as to perform damper-linked non-charged striking. . By this control, the compartments 16a, 16b, 16c, etc. can be used with the inlet dampers 19, 20 and the outlet dampers 22, 23 closed and the dust collecting electrode 1 in an uncharged state at night in the summer when cooling is used. By striking the dust collecting electrode 1 a predetermined number of times, the draft of the furnace 12 is fluctuated, but the dust cleaning effect of the dust collecting electrode 1 can be enhanced as compared with the interval charge striking.

  Then, with reference to FIG. 2, the structural example of the ventilation system in the electric dust collection system 100 is demonstrated. According to the ventilation system of the electric dust collection system 100 shown in FIG. 2, two flue systems are provided. For example, when the two flue series are the A series and the B series, two series of electric dust collection units A1 and A2 are provided in parallel in the A series. Two electrostatic precipitators 15 are provided in the electrostatic precipitator unit A1. Two electrostatic precipitators 15 are also provided in the electrostatic precipitator unit A2. Each electrostatic precipitator 15 is unitized as shown in FIG. The electric dust collector 15 is similarly provided in the B series, but the description thereof is omitted.

  In FIG. 2, the dust collecting pole striking device 24a (see FIG. 15) in the compartment 16a of the section 1S of the electric dust collecting unit A1 is denoted by reference numeral A1-11 for convenience. Similarly, the dust collecting pole striking device 24b (see FIG. 15) in the section 16b of the section 2S is denoted by reference numeral A1-21. Similarly, the dust collecting pole striking device 24c (see FIG. 15) in the compartment 16c of the section 3S is denoted by reference numeral A1-31. Similarly, the dust collecting pole striking device 25a (see FIG. 15) in the section 17a of the section 1S is denoted by reference numeral A1-12.

  Similarly, the dust collecting pole striking device 25b (see FIG. 15) in the section 17b of the section 2S is indicated by reference numeral A1-22. Similarly, the dust collecting pole striking device 25c (see FIG. 15) in the compartment 17c of the section 3S is denoted by reference numeral A1-32. These dust collecting pole striking devices A1-11, A1-21, A1-31, A1-12, A1-22, A1-32 are controlled by the control device 55.

  Further, the inlet damper 19 (see FIG. 15) of the electric dust collection unit A1 is denoted by reference numeral A1-1. The inlet damper 20 (see FIG. 15) is denoted by reference numeral A1-2. The outlet damper 22 (see FIG. 15) is denoted by reference numeral A1-3. The outlet damper 23 (see FIG. 15) is denoted by reference numeral A1-4. These inlet damper A1-1, inlet damper A1-2, outlet damper A1-3, and outlet damper A1-4 are driven by the damper driving device 43 shown in FIG.

  In the first chamber 16 of the section 1S of the electric dust collection unit A2, a dust collecting electrode striking device A2-11 is provided in the same manner as the electric dust collection unit A1. The first chamber 16 of the section 2S is provided with a dust collecting pole striker A2-21. The first chamber 16 of the section 3S is provided with a dust collecting pole striker A2-31. In the second chamber 17 of the section 1S, a dust collecting pole striker A2-12 is provided. In the second chamber 17 of the section 2S, a dust collecting pole striker A2-22 is provided. In the second chamber 17 of the section 3S, a dust collecting pole striker A2-32 is provided. These dust collecting pole striking devices A2-11, A2-21, A2-31, A2-12, A2-22, A2-32 are controlled by the control device 55.

  In addition, an entrance damper A2-1 and an entrance damper A2-2 are provided at the entrance of the electrostatic dust collection unit A2, similarly to the electrical dust collection unit A1. At the outlet, an outlet damper A2-3 and an outlet damper A2-4 are provided. These inlet damper A2-1, inlet damper A2-2, outlet damper A2-3 and outlet damper A2-4 are also driven by a damper driving device 43 as shown in FIG.

  An inlet common damper 49 is provided between the A-series inlet flue 18 and the B-series inlet flue 18, and the A-series flue and the B-series flue are provided on the inlet side of the electrostatic precipitator 15. It is possible to communicate (communicate with) the exhaust gas before electric dust collection. Further, an outlet common damper 59 is provided between the A-series outlet flue 21 and the B-series outlet flue 21, and the A-series flue and the B-series flue are disposed on the outlet side of the electrostatic precipitator 15. The exhaust gas after electrostatic dust collection can be communicated (communication) with

  For example, in maintenance of the A series electric dust collection units A1, A2, etc., the inlet damper A1-1, the inlet damper A1-2, the inlet damper A2- 1. By opening / closing the inlet damper A2-2, outlet damper A1-3, outlet damper A1-4, outlet damper A2-3, and outlet damper A2-4, the A series electric dust collection units A1 and A2 are passed. It can be done.

  Then, the control example of the electrostatic dust collection system 100 is demonstrated with reference to FIGS. 3-12 about the electrical dust collection method which concerns on this invention. In the electric dust collection system 100, it is determined whether or not the operating condition of the coal-fired boiler system corresponds to the interval charge strike condition during execution of the interval charge strike. The operating conditions of the coal-fired boiler system cover the dust concentration of exhaust gas, the EP ash treatment time, and the disclosure time of the damper-linked non-charged strike. In this example, an operation set time for performing most of the interval charge strikes for one day is input via the operation unit 54, and an operation set time for performing a damper-linked non-charge strike at night is input. The

  Under these control conditions, the CPU 53 executes operation settings related to the control of the electric dust collection system 100 in step ST1 of the flowchart shown in FIG. At this time, the operator performs an input operation on the operation unit 54, in addition to the specified value related to the dust concentration and the specified value related to the ash processing time, the operation setting time for the interval charge strike and the operation set time for the damper-linked non-charge strike Enter etc.

  For example, 4 hours from 2 am to 6 am on the current day is set as the operation setting time for the damper-linked non-charge strike. 2:00 am corresponds to the start time of the damper-linked non-charge strike, and 6:00 am corresponds to the end time. As the operation setting time of the interval charge strike, most of the day, for example, 20 hours from 6 am on the current day to 2 am on the next day is set.

  Next, in step ST2, the CPU 53 branches control depending on whether the EP strike mode is automatic or manual. At this time, when the electric dust collector 15 is automatically operated, the operator selects the automatic mode by pressing the selection button 54a shown in FIG. In the automatic mode, the interval charge strike method is set. When the electric dust collector 15 is manually operated, the selection button 54b is pressed and the manual mode is selected. In the manual mode, the damper-linked non-charge strike method is set. When the automatic mode EP strike method is selected, the process proceeds to step ST3.

  In step ST3, the CPU 53 executes interval charge strike. The CPU 53 is configured to always perform interval charge striking based on the operation set time output from the operation unit 54, so that the dust collecting electrode striking devices A1-11, A1-21, A1−31, A1−12, A1−22, A1−32, and dust collector striking devices A2−11, A2−21, A2−31, A2−12, A2−22 of the electric dust collection unit A2, Control A2-32.

  In the interval charging strike, the inlet dampers A1-1 and A1-2 and the outlet dampers A1-3 and A1-4 shown in FIG. 3 are fully opened and the dust collecting electrode 1 shown in FIG. 15 is charged. In the dust collecting electrode striking devices A1-11, A1-21, A1-31, A1-12, A1 so as to intermittently strike the dust collecting electrodes 1 such as the compartments 16a, 16b, 16c. Controls −22, A1−32, etc. The satin shown in FIG. 3 is a state in which the dust collecting electrode 1 shown in FIG. 15 is charged.

  According to the strike timers of the dust collection strikers A1-11, A1-21, A1-31, A1-12, A1-22, A1-32 of the electric dust collection unit A1, the compartment 16a shown in FIG. , 17a are assigned to the dust collecting pole strikers A1-11 and A1-12 of section 1S, as shown in Table 1, perform the strike operation of the dust collecting pole 1 for 4 seconds, and then 29 seconds. The strike operation is stopped. The dust collecting electrode striking devices A1-21 and A1-22 of the section 2S to which the compartments 16b and 17b are assigned execute the striking operation of the dust collecting electrode 1 for 4 seconds, and then perform the striking operation for 63 seconds. To stop. The dust collecting electrode striking devices A1-31 and A1-32 of the section 3S to which the compartments 16c and 17c are assigned perform the striking operation of the dust collecting electrode 1 for 4 seconds, and then perform the striking operation for 96 seconds. To stop.

  Based on such a strike timer, the dust collector strikers A1-11, A1-21, A1-31, A1-12, A1-22, A1-32 are controlled. In this example, the dust collector striking devices A1-11, A1-21, A1-31, A1-12, A1-22, A1-32 are operated for 20 hours from 6 am on the day to 2 am on the next day. An interval charge strike based on the strike timer is executed over a set time. The dust collecting striker A2-11, A2-21, A2-31, A2-12, A2-22, A2-32 of the electric dust collecting unit A2 shown in FIG. The electric dust collection units B1 and B2 are similarly controlled.

  Thereafter, in step ST4, the CPU 53 compares the dust concentration of the exhaust gas with a specified value that serves as a reference when evaluating the dust in the exhaust gas, and branches control according to the comparison result. Here, the dust concentration is Dx, and the specified value is Dth. When the dust concentration Dx is not more than the specified value Dth (DX ≦ Dth), the process proceeds to step ST5.

  In step ST5, the CPU 53 further compares the EP ash treatment time with a specified value that serves as a reference when evaluating the ash treatment time of the EP ash treatment device 42, and branches control according to the comparison result. Here, the EP ash treatment time is Ta, and the specified value is Tth. If this EP ash treatment time is not less than the specified value (Ta ≧ Tth), the process proceeds to step ST6.

  In step ST6, the CPU 53 further compares the current time during execution of the interval charge strike with the set time when executing the damper-linked non-charge strike, and branches the control according to the comparison result. Here, the current time is Tx and the set time is Tb. At this time, the CPU 53 inputs time information indicating the current time Tx when the interval charge strike is performed from the timer 52, and also indicates a set time Tb at which the damper-linked non-charge strike starts from the memory 51. Information is input, and the current time Tx when the interval charge strike is performed is compared with the set time Tb for performing the damper-linked non-charge strike. If the current time Tx is not the set time Tb (Tx ≠ Tb), the process returns to step ST2 and the above-described steps are executed.

  When the dust concentration Dx exceeds the specified value Dth in step ST4 (Dx> Dth), the EP ash treatment time is less than the specified value in step ST5 (Ta <Tth), or the current time in step ST6. When Tx reaches the set time Tb (Tx = Tb), the process proceeds to step ST8 while continuing the interval charge strike. When the soot concentration Dx exceeds the specified value Dth (Dx> Dth), it is assumed that a large amount of soot adheres to the dust collecting electrode 1 and is just before saturation.

  When the EP ash treatment time is less than the specified value (Ta <Tth), the amount of dust collected from each of the compartments 16a, 16b, 16c, etc. decreases, and a large amount of dust adheres to the dust collecting electrode 1. Is assumed. When the current time Tx becomes the set time Tb (Tx = Tb), it is assumed that the current time Tx is the time when the damper-linked non-charge strike is started, in this example, 2 am on that day.

  On the other hand, if the manual mode EP strike method is selected in step ST2, the process proceeds to step ST7. In step ST7, the CPU 53 branches control depending on whether or not the operation selection is linked to the damper. If the operation selection is not damper-linked, the process returns to step ST2 and is executed to repeat the above-described steps.

  If the damper interlock is selected, the process proceeds to step ST8 while continuing the interval charge strike, and the CPU 53 executes the damper interlock non-charge strike. The CPU 53 collects the dust collector striker A1-11, A1-21, A1 so that the damper-linked non-charge strike is performed based on the operation set time (from 2 am to 6 am) output from the memory 51. -31, A1-12, A1-22, A1-32 are controlled.

  In the damper-linked non-charged strike, the inlet dampers A1-1 and A1-2 and the outlet dampers A1-3 and A1-4 are closed in a predetermined order, and in this state, the dust collecting electrode 1 shown in FIG. The dust collecting electrode striking devices A1-11, A1-21, A1-31, A1- so that the dust collecting electrodes 1 such as the compartments 16a, 16b, 16c are beaten a predetermined number of times in a charged state. 12, A1-22 and A1-32 are controlled.

  In this example, when the interval charge strike shown in FIG. 3 is shifted to the damper-linked non-charge strike shown in FIG. 4, the inlet dampers A1-1, A1-2 and the electrostatic dust collection unit A1 shown in FIG. The entrance dampers A2-1 and A2-2 of the electric dust collection unit A2 remain fully open.

  In this state, the outlet dampers A1-3 and A1-4 of the electric dust collection unit A1 are shifted from the fully opened state to the 50% opened state, and the outlet dampers A2-3 and A2-4 of the electric dust collection unit A2 are moved from the fully opened state. Transition to the 55% open state. The dust collection electrodes 1 such as the compartments 16a, 16b, 16c, 17a, 17b, and 17c of the sections 1S to 3S of the electric dust collection units A1 and A2 are in a charged state (see satin in the drawing).

  According to the damper-linked non-charged strike, next, the inlet dampers A1-1 and A1-2 of the electrostatic dust collecting unit A1 and the inlet dampers A2-1 and A2-2 of the electrostatic dust collecting unit A2 shown in FIG. From the fully opened state, the inlet damper A1-1 of the electrostatic dust collection unit A1 shown in FIG. 5 is shifted from the fully opened state to the 50% opened state. Note that the outlet dampers A1-3 and A1-4 of the electric dust collection unit A1 are maintained at 50% open, and the outlet dampers A2-3 and A2-4 of the electric dust collection unit A2 are maintained at 55% open. Yes. The dust collection electrodes 1 such as the compartments 16a, 16b, 16c, 17a, 17b, and 17c of the sections 1S to 3S of the electric dust collection units A1 and A2 remain in a charged state (see satin in the drawing).

  Further, the inlet damper A1-1 and the outlet damper A1-3 of the electric dust collection unit A1 shown in FIG. 6 are maintained while the inlet damper A1-1 of the electric dust collection unit A1 shown in FIG. Transition from the 50% open state to the fully closed state. The outlet damper A1-4 is maintained in an open state of 50%. The outlet dampers A2-3 and A2-4 of the electric dust collection unit A2 are maintained 55% open. The dust collection electrodes 1 such as the compartments 16a, 16b, 16c, 17a, 17b, and 17c of the sections 1S to 3S of the electric dust collection units A1 and A2 remain in a charged state (see satin in the drawing).

  The inlet damper A1-1 and outlet damper A1-3 of the electric dust collection unit A1 shown in FIG. 7 are fully closed. In this state, the dust collection electrode 1 of the section 1S of the section 1S and the section 16b of the section 2S of the electric dust collection unit A1 shown in FIG. Dust strike is executed by driving the dust collectors A1-11 and A1-21.

  In the compartment 16a of the section 1S and the compartment 16b of the section 2S of the electric dust collection unit A1 shown in FIG. 8, the collection of the compartments 16a and 16b is performed by the striking of the dust collector striking devices A1-11 and A1-21. The dust that has fallen from the dust electrode 1 is discharged and accommodated in the EP ash treatment device 42 via the hopper 41 shown in FIG. In the EP ash treatment device 42, dust is ash-treated.

  Except for the compartment 16a of the section 1S and the compartment 16b of the section 2S of the electrostatic dust collection unit A1, the compartment 16c of the section 3S and other electrostatic dust collection units A2 and B series of electrostatic dust collection units B1 and B2 are The interval charge strike is continued (see Nashiji in the figure).

  And after making the dust collection pole 1 of the compartment 16a of the section 1S and the compartment 16b of the section 2S of the electrostatic dust collection unit A1 shown in FIG. 9 into a charged state, as shown in FIG. The dust collecting electrode 1 in the compartment 16c of the section 3S is set to an uncharged state. The dust collecting strike device A-31 is driven to carry out the dust strike. In the compartment 16c, the soot that has fallen from the dust collecting electrode 1 of the compartment 16c by the strike of the dust collecting striker A1-31 is discharged and accommodated in the EP ash treatment device 42 through the hopper 41 shown in FIG. Is done. In the EP ash treatment device 42, dust is ash-treated.

  The compartments 16a and 16b of the sections 1S and 2S, excluding the compartment 3c of the section 3S of the electrostatic dust collection unit A1, are shifted to interval charge strike, and the other electrostatic dust collection units A2 and B series of electrical dust collection are performed. Units B1 and B2 continue the interval charge strike (see satin in the figure).

  Then, the entrance damper A1-1 and the exit damper A1-3 shown in FIG. 7 are fully closed by charging the dust collection electrode 1 in the compartment 16c of the section 3S of the electric dust collection unit A1 shown in FIG. As a result, the dust collection electrodes 1 of the compartments 16a, 16b, and 16c of the sections 1S to 3S return to the charged electrostatic dust collection unit A1. As a result, the damper-linked non-charge strike in the first chamber 16 of the electric dust collection unit A1 is completed.

  Similarly, the damper-linked non-charged striking of the second chamber 17 of the electrostatic dust collection unit A1 is continued, and then the damper-linked uncharged striking of the first chamber 16 of the electrostatic dust collecting unit A2 is performed. Then, the damper-linked uncharged strike of the second chamber 17 of the electric dust collection unit A2 is executed. As a result, the damper-linked non-charge strike of the A-series electric dust collection units A1 and A2 is completed. Thereafter, damper-linked non-charge strikes of the B series electric dust collection units B1 and B2 are executed.

  The strike time for the damper-linked non-charge strike in the first chamber 16 of the electric dust collection unit A1 is about 30 minutes. It takes 2 hours for the damper-linked non-charged strike of the A series electric dust collection units A1 and A2. Similarly, the damper-linked non-charged striking of the B series electrostatic dust collection units B1 and B2 requires 2 hours, so the A and B series electrostatic dust collection units A1, A2, B1 and B2 take 4 hours. In short, the damper-linked non-charge strike is made.

  As a result, the dust collector striking devices A1-11, A1-21, A1-31, A2- so that the damper-linked non-charged striking is performed at night based on the operation setting time from 2:00 am to 6:00 am 11, A2-21, A2-31 can be controlled. By this control, it continues from 6:00 am on the day of the interval charge strike that was set in the daytime in summer during cooling use to 2:00 am on the next day (first operation setting time: 20 hours), The control is periodically switched at the set time Tb or the like, and the damper-linked non-charge strike can be executed using 4 hours from 2 am to 6 am.

  And it transfers to step ST9 and control branches depending on whether driving | operation selection is automatic. If the operation selection is not automatic, the process returns to step ST8 and the CPU 53 continues the damper-linked non-charge strike. When the operation selection is automatic, the process proceeds to step ST20, where the CPU 53 compares the number of operations of the damper-linked non-charged strike with the set number of times, and branches control according to the comparison result.

  Here, the number of operations is Nx, and the set number is Nb. At this time, the CPU 53 inputs the number-of-times information indicating the number of operation times Nx of the damper-linked non-charge strike, and also inputs the setting information indicating the set number of times Nb of the damper-linked uncharged strike from the memory 51, The number of strikes Nx is compared with the set number Nb. When the operation number Nx does not match the set number Nb (Tx ≠ Tb), the process returns to step ST8 and returns to the above-described step ST8 to repeat the damper-linked non-charge strike. When the operation number Nx matches the set number Nb, the process returns to step ST2 to repeat the above steps.

  As described above, according to the electric dust collection system 100 as the embodiment, the dust collecting striker A1-11, A1-21, A1-31 so that the interval charge strike is always executed (used regularly). , A1-12, A1-22, and A1-32, and determines whether the operating condition of the boiler system corresponds to the interval charge strike condition during the interval charge strike. Based on the determination result, the dust collector striking devices A1-11, A1-21, A1-31, A1-12, A1-22, A1-32 are controlled so that the damper-linked uncharged striking is performed. Will come to do.

  When the dust collector striker A1-11, A1-21, A1-31, A1-12, A1-22, A1-32 is controlled to perform this interval charge strike, the damper-linked uncharged Compared to the beating, the power consumption related to the draft loss can be omitted. Moreover, even if the power consumption associated with the charging of the dust collection electrode 1 is subtracted from the power consumption related to the draft loss, the in-house power related to the electric dust collection system 100 can be reduced.

  In addition, if the dust collector striking devices A1-11, A1-21, A1-31, A1-12, A1-22, A1-32 are controlled so that the damper-linked uncharged striking is performed, Although accompanied by 12 draft fluctuations, etc., the dust cleaning effect of the dust collecting electrode 1 can be enhanced as compared with the interval charge strike. In this way, the interval charge strike can be executed mainly during normal operation, and the damper-linked non-charge strike can be executed as necessary. As a result, the power cost of the ventilation system during normal operation can be reduced, the cost of the electric dust collection system 100 can be reduced, and the coal-fired boiler system can be operated efficiently.

  Here, referring to FIG. 13, IDF power costs in the electric dust collection system 100 according to the present invention and the conventional method will be compared. As described above, according to the operation method of the electric dust collection system 100, the interval charge striking method II is used (main), and the electric dust collection units A1, A2, etc. are not suitable for operation or the dust collection electrode 1 is cleaned. In this case, the damper-linked non-charge strike method I is selected. The damper-linked non-charge strike method I is executed only once a day, for example, at night (a cycle once a day).

  In FIG. 13, the vertical axis on the left is the IDF motor current [A], which is the current supplied to the motor of the A series induction fan 30. The vertical axis on the right is the EP current [A]. For example, the collection of the compartments 16a, 16b, and 16c and the compartments 17a, 17b, and 17c of the sections 1S to 3S of the A-series electrostatic dust collection units A1 and A2 is performed. It is the sum total of the charging current supplied between the dust electrode 1 and the discharge electrode 2. The horizontal axis represents the operating time of the electric dust collection system 100, and 4 hours of the day are set to the damper-linked non-charge strike method I, and the remaining 20 hours are set to the interval charge strike method II.

  According to the damper-coupled non-charge strike method I, with respect to the IDF motor current [A], the Idf current peaks at 350 [A], and if the current is df [= 340 [A], ± 10 [A] It has fluctuated. According to the interval charge strike method II, the Idf current peaks at 325 [A] and is based on Ifd current = 315 [A], ± 10 [A] compared to the damper-linked non-charge strike method I It is fluctuating.

  Regarding the IDF motor current [A], the difference between the Idf current = 340 [A] of the damper-coupled non-charging strike method I and the Idf current = 315 [A] of the interval charge strike method II is 25 [A]. is there. According to the interval charge strike method II compared with the damper-linked non-charge strike method I, the IDF power cost can be reduced by about 7%.

  Further, according to the damper-linked non-charged striking method I, with respect to the charging current, the EP current between the dust collecting electrode 1 and the discharge electrode in the corresponding compartment is stopped when the dust collecting electrode 1 is beaten (uncharged state). Therefore, it decreases from the steady value 140 [A]. According to the interval charge strike method II, the EP current is fixed at approximately 140 [A].

  In the above-described example, the interval charge striking method II is executed in 20 hours in one day, and the load current of the induction fan 30 (IDF) is reduced. As a result, the cost can be reduced by 24,000 thousand yen per year. With the interval charge striking method II, it is possible to suppress the moving blade opening degree of the induction fan 30 (IDF) in the summer heavy load period.

  INDUSTRIAL APPLICABILITY The present invention is extremely suitable when applied to an electric dust collector and a control method thereof that are provided in a ventilation system of an exhaust gas treatment system for coal-fired power to remove soot and dust.

DESCRIPTION OF SYMBOLS 10 Pushing ventilator 11 Air preheater 12 Furnace 13 Exhaust gas denitration apparatus 14 Heat recovery device 15 Electric dust collector 15a Case 15b Partition plate 16 1st chamber 16a Partition chamber (front chamber)
16b compartment (intermediate room)
16c compartment (rear room)
17 Second room 17a Compartment room (front room)
17b Compartment room (intermediate room)
17c Compartment (rear room)
18 Inlet flue 19, 20, A1-1, A1-2 Inlet damper 21 Outlet flue 22, 23, A1-3, A1-4 Outlet damper 24a, 24b, 24c, A1-11, A1-21, A1- 31 Dust collector striker 25a, 25b, 25c, A1-12, A1-22, A1-32 Dust collector striker 30 Induction fan 32 Exhaust gas desulfurizer 35 Reheater 40 Chimney 100 Electric dust collection system

Claims (6)

It is installed in the ventilation system of a balanced ventilation boiler system that has a forced draft fan that sends combustion air into the furnace and an induction ventilator that controls the pressure in the furnace, and removes dust in the exhaust gas from the furnace. In order to remove, the inside of the case is divided into a plurality of compartments, each of which can be charged independently, a dust collecting electrode provided in each compartment and collecting the dust, and controlling the flow of the exhaust gas. Therefore, in an electric dust collection system comprising an inlet damper provided in an inlet flue of the case, an outlet damper provided in an outlet flue, and a dust collecting electrode striking device for striking the dust collecting electrode ,
With the inlet damper and the outlet damper opened, and the dust collecting electrode charged, the operation of repeating the striking intermittently against the dust collecting electrode of the compartment is referred to as interval charging striking,
The operation of performing a predetermined number of strikes on the dust collecting electrode in the compartment with the inlet damper and the outlet damper closed and the dust collecting electrode in an uncharged state When hitting
An operation unit for selecting a strike mode for selecting either the interval charge strike or the damper-linked non-charge strike,
A detector for detecting operating conditions of the boiler system;
A control device for controlling the dust collecting striker based on operating conditions of the boiler system obtained from the detection unit ;
A concentration detector for detecting the concentration of dust in the exhaust gas discharged from the furnace;
An ash treatment device for treating the dust discharged from each of the compartments ,
The controller is
Controlling the dust collecting striker so as to always carry out the interval charge strike according to the selection by the operation unit ;
It is determined whether or not the operating condition of the boiler system corresponds to the interval charge strike condition during the execution of the interval charge strike,
Controlling the dust collecting electrode striking device to perform the damper-linked non-charged striking based on the determination result ;
Further, the dust concentration value based on the dust concentration information obtained from the concentration detection unit is compared with a discrimination reference value for determining a strike method,
When the dust concentration value is less than the discrimination reference value,
Controlling the dust collecting striker so as to always carry out the interval charge strike,
If the dust concentration value exceeds the criterion value,
Controlling the dust collecting striker to carry out the damper-linked non-charged strike,
Further, the ash treatment time of the dust treated by the ash treatment device is compared with the discrimination reference value for determining the strike method,
When the ash treatment time is equal to or less than a discrimination reference value,
An electric dust collection system that controls the dust collecting pole strike device so as to always carry out the interval charge strike . The controller is
If the ash treatment time exceeds the criterion value,
Electrostatic precipitator system according to claim 1, characterized in that to control the dust Gokutsuchi punching device to perform the damper interlocking uncharged hammering. A time input unit for inputting a start time and an end time for performing the damper-linked non-charge strike,
A time output unit that outputs time information indicating the current time when performing the interval charge strike or damper-linked non-charge strike,
It is a case where the interval charge strike is always performed except for the operation set time for performing the damper-linked non-charge strike input by the time input unit,
The controller is
While inputting the time information indicating the current time when the interval charge strike is performed from the time output unit, the start time for performing the damper-linked non-charge strike is input from the time input unit,
Compare the current time when performing the interval charge strike and the start time for carrying out the damper-linked non-charge strike,
When the current time coincides with the start time, the dust collecting electrode striking device is controlled so as to start the implementation of the damper-linked non-charge striking while continuing the interval charge striking. The electric dust collection system according to claim 1 or 2 . The time input unit is
A first operation set time for performing most of the interval charge strike for one day is input,
The second operation set time for performing the damper-linked non-charged strike at night is input,
The controller is
Controlling the dust collecting electrode striking device to perform interval charge striking based on the first operation setting time output from the time input unit;
The electric dust collection system according to claim 3 , wherein the dust collecting pole strike device is controlled so that the damper-linked non-charge strike is performed at night based on the second operation setting time. It is installed in the ventilation system of a balanced ventilation boiler system that has a forced draft fan that sends combustion air into the furnace and an induction ventilator that controls the pressure in the furnace, and removes dust in the exhaust gas from the furnace. In order to remove, the inside of the case is divided into a plurality of compartments, each of which can be charged independently, a dust collecting electrode provided in each compartment and collecting the dust, and controlling the flow of the exhaust gas. Therefore, an electric dust collection system comprising an inlet damper provided in the inlet flue of the case, an outlet damper provided in the outlet flue, and a dust collecting electrode striking device that strikes the dust collecting electrode. ,
Detecting operating conditions of the boiler system;
Based on the operating conditions of the detection by said boiler system running and a step of controlling the dust collector Gokutsuchi punching device,
When controlling the dust collecting striker,
With the inlet damper and the outlet damper opened, and the dust collecting electrode charged, the operation of repeating the striking intermittently against the dust collecting electrode of the compartment is referred to as interval charging striking,
The operation of performing a predetermined number of strikes on the dust collecting electrode in the compartment with the inlet damper and the outlet damper closed and the dust collecting electrode in an uncharged state When hitting
Operated to select either one of the interval charge strike or the damper-linked non-charge strike;
Controlling the dust collecting electrode striking device to always perform the selected interval charge striking;
Determining whether or not the operating condition of the boiler system corresponds to the interval charge strike condition during the execution of the interval charge strike;
Performing the step of controlling the dust collecting electrode striking device so as to perform the damper-linked non-charged striking based on the determination result ,
Further, a step of comparing the dust concentration value based on the dust concentration information indicating the concentration of the dust in the exhaust gas discharged from the furnace with a determination reference value for determining a strike method;
When the dust concentration value is equal to or less than a discrimination reference value, controlling the dust collecting electrode striking device to always perform the interval charge striking; and
When the dust concentration value exceeds a discrimination reference value, the step of controlling the dust collecting electrode striking device to perform the damper-linked non-charged striking,
Further, the step of comparing the ash treatment time of the dust discharged from each of the compartments with a determination reference value for determining a striking method,
And a step of controlling the dust collecting electrode striking device so as to always perform the interval charge striking when the ash treatment time is equal to or less than a discrimination reference value .   If the ash treatment time exceeds the criterion value,
  The electrostatic dust collection method according to claim 5, wherein the step of controlling the dust collecting pole striker so as to perform the damper-linked non-charge strike is performed.

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