JP2016000377A - Power station operation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power station operation system capable of performing damper-linked hammering appropriately.SOLUTION: In a power station operation system having an electric dust collector for removing smoke dust in exhaust gas from a furnace where coal is burnt, a dust collecting electrode hammering device for performing the hammering of a dust collecting electrode, and an operation control device for executing control of the dust collecting electrode hammering device, the operation control device includes a coal property database for associating an ash content and a total sulfur content of coal with the number of times of hammering, and storing them, an interval hammering control part for performing the hammering of the dust collecting electrode in a state that an inlet damper and an outlet damper of the electric dust collector are open, and a damper-linked hammering control part for performing the hammering of the dust collecting electrode in a state that the inlet damper and the outlet damper of the electric dust collector are closed. When the hammering mode is switched from the interval hammering to the damper-linked hammering, the coal property database is referred to and the number of times of the hammering is set based on the ash content and the total sulfur content of the coal currently used.

Description

  The present invention relates to a power plant operation system applied to removal of soot in exhaust gas (hereinafter simply referred to as exhaust gas) generated by coal combustion in a coal-fired power plant.

  Conventionally, coal-fired boiler systems burn coal, generate high-pressure steam, drive steam turbines to rotate generators, and operate coal-fired power plants that generate electricity to supply power to consumers. ing. This type of coal-fired power plant is equipped with an exhaust gas treatment system for treating exhaust gas.

The exhaust gas treatment system includes an electric dust collector that removes dust from the exhaust gas, and a ventilator that attracts the exhaust gas from the electric dust collector. The ventilator is provided with a moving blade that opens and closes the outlet of the electric dust collector, and the input pressure that the ventilator receives from the exhaust gas can be adjusted by the opening degree of the moving blade.
The input pressure to the ventilator is controlled so that the furnace pressure becomes constant when combustion air is pushed into the furnace. However, when the air density in summer is low, the amount of combustion air pushed into the furnace increases, and the input pressure to the ventilator increases accordingly. As a result, the blade opening increases to keep the furnace pressure constant.

  By the way, the electric dust collector is provided with a dust collecting electrode striking device for striking the dust collecting electrode, and this dust collecting electrode striking device adheres to the dust collecting electrode by striking the dust collecting electrode. The dust that has been removed is peeled off. Thereby, the dust collection function of the electric dust collector is maintained.

  If the inlet and outlet of the electrostatic precipitator are closed in order to strike the precipitator of the electrostatic precipitator and remove the dust from the precipitator, the electrostatic precipitator becomes a resistance in the flow of exhaust gas. Therefore, it is necessary to further increase the moving blade opening of the ventilator in order to make the furnace pressure constant. However, when the moving blade opening of the ventilator increases and exceeds the control range of the moving blade opening, the furnace pressure control may be impossible. For this reason, when the outside air temperature rises, it is necessary to ensure the margin of the ventilation system in the electric dust collector so that the electric dust collector does not become a resistance.

  Therefore, conventionally, a technique described in Patent Document 1 has been proposed. According to Patent Document 1, a control device that controls a dust collecting electrode striking device that strikes the dust collecting electrode and separates the dust from the dust collecting electrode based on the operating conditions of the boiler system is provided. Then, the dust collecting electrode striking device is controlled so that the interval striking which opens the ventilation system and strikes the charged dust collecting electrode is always performed. Further, it is determined whether or not the operating condition of the boiler system corresponds to the interval hitting condition during the interval hitting, and the ventilation system is closed and the non-charged dust collecting electrode is based on the determination result. A technique has been proposed for controlling the dust collecting and punching device so as to perform a damper-linked hammering that strikes the drum.

  With this configuration, when the dust collecting electrode striking device is controlled so as to always perform interval striking, the inlet damper and the outlet damper are opened and the dust collecting electrode in the compartment is opened. Dust is removed by intermittent hitting. As a result, it is possible to reduce the power consumption related to the draft loss as compared with the damper-linked strike. In addition, it is possible to reduce the in-house power related to the power plant operation system even if the power consumption associated with the dust collection electrode charging is subtracted from the power consumption related to the draft loss. In addition, when the dust collecting electrode striking device is controlled so as to perform the damper linked striking, the inlet and outlet dampers are closed and the dust collecting electrode is not charged. However, since the beating is performed, the draft of the furnace is fluctuated, but the dust cleaning effect of the dust collecting electrode can be enhanced as compared with the interval beating. In this way, the exhaust gas treatment system of the power plant can be operated efficiently.

JP 2012-71280 A

  However, in the past, there is no clear standard for how much the damper-linked strike is executed, so there is a risk that the damper-linked strike will be performed more than necessary or the damper-linked strike will be insufficient. Performing a damper-linked strike more than necessary leads to an increase in the ventilation system power cost and an increase in the cost of load control due to insufficient ventilation system tolerance. There is a risk that the dust collection performance will be reduced and the exhaust gas concentration will exceed the environmental regulation value.

  It is an object of the present invention to provide a power plant operation system that solves such problems and makes it possible to appropriately perform damper interlocking strikes.

  In order to achieve the above object, the present invention has the following configuration.

  (1) Electric dust collector that removes dust in exhaust gas from a furnace that burns coal, dust collector strike device installed in the dust collector, and control of the dust collector strike device In the power plant operation system including the operation control device to perform, the electrostatic precipitator includes a case in which the exhaust gas circulates, a compartment in which the inside of the case is partitioned into a plurality, and each can be charged independently. A dust collecting electrode provided in each of the compartments for collecting the dust, an inlet damper provided in an inlet flue of the case for controlling a flow of the exhaust gas, and an outlet flue of the case The dust collecting electrode striking device strikes the dust collecting electrode, and the operation control device associates the ash content of coal, the total sulfur content, and the number of strikes. And store the coal property database, the inlet damper and the front The dust collecting electrode striking device is configured to perform interval striking that repeats striking intermittently with respect to the dust collecting electrode in the compartment in a state where the outlet damper is opened and the dust collecting electrode is charged. An interval striking control unit for controlling the damper, and a damper for striking the dust collecting electrode in the compartment with the inlet damper and the outlet damper being closed and the dust collecting electrode being uncharged A damper-linked strike control unit that controls the dust collecting pole striker to perform linked strikes, and when switching from interval strikes to damper-linked strikes, the coal property database is referred to and used at present. A damper-operated strike frequency setting unit for setting the strike frequency corresponding to the ash content and total sulfur content of coal.

  According to (1), since the number of strikes is set according to the ash content and total sulfur content of the coal burned in the furnace, for example, when the total sulfur content is low or the ash content is high, the strike is performed. The number of strikes can be set to be reduced when the total sulfur content is high or the ash content is low. As a result, it is possible to reduce the occurrence of the damper-interlocked hitting more than necessary or the shortage of the damper-linked hitting, and the damper-linked hitting can be appropriately performed.

  (2) In (1), the apparatus further comprises a soot concentration detecting device for detecting the soot concentration in the exhaust gas discharged from the furnace, wherein the damper interlocking hitting control unit detects the soot dust from the detection result of the soot concentration detecting device. The power plant operation system is characterized in that the concentration change rate of the dust is obtained, and when the dust concentration and the concentration change rate exceed a preset threshold value, the interval strike is switched to the damper linked strike.

  According to (2), when there is a possibility that the dust collection performance of the electric dust collector has deteriorated during operation of the furnace, it is possible to switch from the interval strike to the damper-linked strike as necessary. This makes it possible to maintain the dust collection performance of the electric dust collector.

  According to the present invention, by providing a reference for setting the number of times that the damper interlocking strike is performed, an increase in the ventilation system power cost by performing the damper interlocking strike more than necessary, and load suppression due to insufficient ventilation system tolerance In addition, it is possible to reduce an excess of the environmental regulation value of the exhaust gas concentration due to a decrease in the dust collection performance of the electrostatic precipitator due to a lack of damper-linked strike.

It is a block diagram which shows the schematic structural example of the ventilation system in the exhaust gas treatment system of a thermal power plant. It is a figure which shows the structural example of the electric dust collector. It is a block diagram which shows schematic structure of the control system of the power plant operation system 100 in one Embodiment of this invention. It is explanatory drawing which shows the coal property database 51a. It is a figure which shows the flow of the drive control of a dust collecting pole striker. It is a flowchart which shows the striking number setting process of step ST14 shown in FIG.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
First, a ventilation system of a coal-fired exhaust gas treatment system to which a dust collection system according to an embodiment of the present invention is applied will be described with reference to FIG.

<Overall configuration example of ventilation system of coal-fired exhaust gas treatment system>
FIG. 1 is a block diagram illustrating a schematic configuration example of a ventilation system in an exhaust gas treatment system of a thermal power plant. According to the ventilation system of the thermal power plant shown in FIG. 1, a so-called balanced ventilation boiler system is provided, which is generally used in a coal-fired thermal power plant.

  The ventilation system of this thermal power plant includes an air preheater 11 (abbreviated as AH in FIG. 1) and an exhaust gas denitration device 13 connected to the furnace 12, a forced draft fan 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 ventilator 30 (abbreviated as IDF in the figure), and exhaust gas desulfurization device 32 And a reheater 35 and a chimney 40.

  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 through a flue. 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. A push ventilator 10 is connected to the air preheater 11 through an air duct. The forced air blower 10 sucks in combustion air and supplies the air into the furnace 12.

  A heat recovery device 14 is connected to the air preheater 11 via a flue. An electric dust collector 15 (Electrostatic Precipitator) is connected to the heat recovery unit 14 via a flue (dust). 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 the dust in the exhaust gas, passes the charged particles in the electric field (between the electrodes), and separates and collects the dust from the exhaust gas. is there. The configuration of the electric dust collector 15 will be described later with reference to FIG.

  An induction fan 30 is connected to the outlet flue 21 (see FIG. 2) of the electric dust collector 15. In order to control the pressure inside the furnace 12, the induction fan 30 sucks the exhaust gas from the electrostatic precipitator 15 from which dust is removed, sends it to the exhaust gas desulfurization device 32, and releases it from the chimney 40 to the atmosphere. 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. Between the heat recovery unit 14 and the reheater 35, exhaust gas from which sulfur oxide has not been removed by the exhaust gas desulfurization device 32 (hereinafter referred to as untreated gas) circulates. The heat recovery unit 14 exchanges heat between the exhaust gas and the untreated gas so as to absorb heat from the exhaust gas. 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.

<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. 2 includes two electrostatic precipitator units 15c and 15d. Each of the electrostatic dust collection units 15c and 15d has a dust collection electrode 1, a discharge electrode 2, a case 15a, a partition plate 15b, inlet dampers 19 and 20, and outlet dampers 22 and 23.

  The partition plate 15b is arranged in a direction along the flow of exhaust gas (hereinafter referred to as a gas flow direction) inside the case 15a, and the inside of the case 15a is divided into a first chamber 16 and a second chamber 17 by the partition plate 15b. Yes. 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, an electric field (corona discharge) is formed between the dust collecting electrode 1 and the discharge electrode 2 by flowing a DC high voltage current (EP current) between the dust collecting electrode 1 and the discharge electrode 2. The Further, in the electrostatic precipitator 15, after the exhaust gas containing soot passes through the inlet flue 18 and the flow velocity distribution is made uniform by a baffle plate (not shown), the exhaust gas is separated from the dust collection electrode 1 and the discharge electrode 2. It is introduced into the electric field (corona discharge) formed between the two. 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. Then, the dust is peeled off from the surface of the dust collecting electrode 1 by the impact force of the strike by the dust collecting electrode strike device 24a, 24b, 24c, 25a, 25b, 25c, and this dust falls on the hopper 41 (see FIG. 3). And it is comprised so that it may be collected by EP ash processing apparatus 42 (refer FIG. 3). The electric dust collector 15 can perform a damper opening and closing operation.

  The damper opening hammering means that the entrance damper 19 and the outlet damper 22 are fully opened and are in a charged state (ON state), and the compartment 16a (front chamber) of the first chamber 16 by the dust collecting pole hammering devices 24a and 24b. And intermittently striking each dust collecting electrode 1 of the compartment 16b (intermediate chamber). The damper closing strike means that the inlet damper 19 and the outlet damper 22 of the first chamber 16 shown in FIG. 2 are fully closed at a predetermined timing to temporarily block the flow of exhaust gas, and further, no charge (charge OFF). In this state, the dust collecting electrode 1 of the compartments 16a, 16b, 16c is beaten.

  The damper closing hammer can clean the compartments 16a, 16b, 16c more efficiently than the damper opening hammer, but temporarily blocks the flow of exhaust gas. On the other hand, in the case of the damper open hammering, the dust is easily scattered by the hammering, but the flow of the exhaust gas is not blocked.

<Configuration example of ventilation system in power plant operation system 100>
Next, a configuration example of the ventilation system in the power plant operation system 100 will be described. According to the ventilation system of the power plant operation system 100 shown in FIG. 2, two flue systems are provided. For example, when two flue series are designated as A series and B series, the electric dust collector 15 is provided for each series. The A series of electrostatic dust collection units 15c and 15d are referred to as electrostatic dust collection units A1 and A2, and the B series of electrostatic dust collection units 15c and 15d are referred to as electrical dust collection units B1 and B2. In the A-series electrostatic precipitator 15, electrostatic precipitator units A1 and A2 are provided in parallel. In the B series electrostatic precipitator 15, two systems of electrostatic precipitator units B1 and B2 are provided in parallel.

  For convenience, the dust collecting electrode striking device 24a in the compartment 16a of the section 1S of the electric dust collecting unit A1 is denoted by reference numeral A1-11. Similarly, the dust collecting pole striking device 24b in the section 16b of the section 2S is denoted by reference numeral A1-21. Similarly, the dust collecting and punching device 24c in the section 16c of the section 3S is denoted by reference numeral A1-31. Similarly, the dust collecting and punching device 25a in the section 17a of the section 1S is denoted by reference numeral A1-12.

  Similarly, the dust collecting and punching device 25b in the compartment 17b of the section 2S is denoted by reference numeral A1-22. Similarly, the dust collecting and hammering device 25c 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, and A1-32 are controlled by a control device 55 (see FIG. 3).

  The inlet damper 19 of the electric dust collection unit A1 is denoted by reference numeral A1-1. The inlet damper 20 is indicated by reference numeral A1-2. The outlet damper 22 is indicated by reference numeral A1-3. The outlet damper 23 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 a damper driving device 43 (see FIG. 3).

  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. In the first chamber 16 of the section 3S, a dust collecting pole striker A2-31 is provided. 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 electrode striking device A2-32 is provided. These dust collecting pole striking devices A2-11, A2-21, A2-31, A2-12, A2-22, and A2-32 are controlled by a control device 55 (see FIG. 3).

  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 (see FIG. 3) 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- cooperate with the opening / closing operation of the inlet common damper 49 and the outlet common damper 59. 1. By opening / closing the inlet damper A2-2, the outlet damper A1-3, the outlet damper A1-4, the outlet damper A2-3, and the outlet damper A2-4, the A series electric dust collection units A1 and A2 are passed. It can be done.

<Configuration of this embodiment>
FIG. 3 is a block diagram showing a schematic configuration of a control system of the power plant operation system 100 in one embodiment of the present invention.

  The power plant operation system 100 is applicable to a coal-fired boiler system, and is installed in a ventilation system of a balanced ventilation type boiler system and functions to remove dust in the exhaust gas from the furnace 12. The power plant operation system 100 includes an electric dust collector 15, a dust collector striking device 24 a, 24 b, 24 c, 25 a, 25 b, 25 c, an EP ash treatment device 42, a damper drive device 43, and a dust concentration detector. 44, a control device 55 corresponding to the operation control device, an operation unit 57, and a monitor 58.

The control device 55 controls the power plant operation system 100 as a whole, and includes the electric dust collector 15, the dust collector striker 24a, 24b, 24c, 25a, 25b, 25c, the induction fan 30, The EP ash treatment device 42, the damper drive device 43, the dust concentration detection device 44, the operation unit 57, and the monitor 58 are communicably connected.
The electric dust collector 15 is as described with reference to FIG.

  The dust collecting and punching devices 24a, 24b, 24c, 25a, 25b, and 25c are driven and controlled by control signals S24a, S24b, S24c, S25a, S25b, and S25c from the control device 55. The control device 55 mainly performs interval strikes during normal operation, and the dust collector strikers 24a, 24b, 24c, 25a, 25b, so as to execute damper-linked strikes in a preset time zone. 25c is controlled.

  In the interval strike, the above-described damper opening strike is executed, and in the damper-linked strike, the above-described damper closing strike is executed.

  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, and processes the dust based on the ash treatment control signal S42 from the control device 55. And 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 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 from the control device 55. 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 the motor that drives the inlet damper 19. The damper control signal S20 is output from the damper driving device 43 to the motor that drives the inlet damper 20. The damper control signal S22 is output from the damper driving device 43 to the motor that drives the outlet damper 22. The damper control signal S23 is output from the damper driving device 43 to the motor that drives the outlet damper 23.

  The soot concentration detector 44 detects the soot concentration 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 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 operation unit 57 inputs various types of information to the control device 55 by the operation of the worker. The monitor 58 displays various information related to the power plant operation system 100.

  As illustrated in FIG. 3, the control device 55 includes a memory 51, a timer 52, and a CPU 53. The CPU 53 is a central processing unit that controls the entire power plant operation system 100. The memory 51 stores information input at the time of initial setting and the like, various programs for controlling the power plant operation system 100, a coal property database 51a that is referred to when performing a damper linked strike, and the like. Yes. The timer 52 counts the current time, and outputs a switching request for switching the strike to the damper-linked strike when the current time for performing the damper-linked strike is reached.

  By executing the program stored in the memory 51, the CPU 53 functions as an interval strike control unit, a damper linked strike control unit, and a damper linked strike count setting unit. The interval hitting control unit controls the dust collecting pole hitting devices 24a, 24b, 24c, 25a, 25b, and 25c so as to execute the interval hitting. The damper interlocking strike control unit controls the dust collecting strikers 24a, 24b, 24c, 25a, 25b, and 25c so as to execute the damper interlocking strike in a preset time zone. The damper-linked strike count setting section refers to the coal property database when switching from interval strike to damper-linked strike, and the number of strikes based on the currently used coal ash and total sulfur. Set.

<Specific example of interval strike>
In the interval strike, the inlet dampers A1-1, A1-2, A2-1, A2-2 and the outlet dampers A1-3, A1-4, A2-3, A2-4 in the A series shown in FIG. Is fully open. The same applies to the B series.

  The strike of the dust collecting electrode 1 (see FIG. 2) is performed from the A series. First, in the electric dust collecting unit A1, the dust collecting and punching device A1-11, the dust collecting and punching device A1-21, the dust collecting and punching device A1-31, the dust collecting and punching device A1-12, The dust electrode striker A1-22 and the dust collector striker A1-32 are driven in this order. That is, the dust collection electrode 1 is beaten in the order of the compartment 16a, the compartment 16b, the compartment 16c, the compartment 17a, the compartment 17b, and the compartment 17c.

  After hitting by the six dust collecting pole hitting devices in the electric dust collecting unit A1, hitting is performed in the electric dust collecting unit A2. Similarly, in the electric dust collecting unit A2, the dust collecting striker A2-11, the dust collecting striker A2-21, the dust collecting striker A2-31, the dust collecting striker A2-12, The dust collector strike device A2-22 and the dust collector strike device A2-32 are driven in this order.

  After the dust collecting electrode 1 is beaten in the A series electric dust collection units A1 and A2, the dust collecting electrode is beaten in the B series. Since the strike of the dust collecting electrode 1 in the B series is the same as that in the A series, the description thereof is omitted.

<Specific example of damper linked strike>
In the damper interlocking strike, first, the inlet damper A1-1 and the outlet damper A1-3 are fully closed, the inlet dampers 1-2, A2-1, and A2-2 are fully opened, and the outlet dampers A1-4, A2-3 and A2-4 are opened about 50%. Next, the dust collection electrode striking device A1-11, the dust collection electrode striking device A1-21, and the dust collection electrode striking device A1-31 are driven in this order, and the compartment 16a in the A-line electric dust collection unit A1 is driven. The dust collecting electrode 1 of the compartment 16b and the compartment 16c is beaten.

  Next, the inlet damper A1-2 and the outlet damper A1-4 are fully closed, the inlet dampers A1-1, A2-1, A2-2 are fully opened, and the outlet dampers A1-3, A2-3, A2- 4 is about 50% open. Next, the dust collecting pole striking device A1-12, the dust collecting pole striking device A1-22, and the dust collecting pole striking device A1-32 are driven in this order, and the compartment 17a in the A series electric dust collecting unit A1 is driven. The dust collecting electrode 1 of the compartment 17b and the compartment 17c is beaten.

  Next, the inlet damper A2-1 and the outlet damper A2-3 are fully closed, the inlet dampers A1-1, A1-2, and A2-2 are fully opened, and the outlet dampers A1-3, A1-4, A2- 4 is about 50% open. Next, the dust collecting pole striker A2-11, the dust collector striker A2-21, and the dust collector striker A2-31 are driven in this order, and the compartments 16a in the A-series electric dust collecting unit A2 are driven. The dust collecting electrode 1 of the compartment 16b and the compartment 16c is beaten.

  Next, the inlet damper A2-2 and the outlet damper A2-4 are fully closed, the inlet dampers A1-1, A1-2, and A2-1 are fully opened, and the outlet dampers A1-3, A1-4, A2- 3 is about 50% open. Next, the dust collecting and punching device A2-12, the dust collecting and punching device A2-22, and the dust collecting and punching device A2-32 are driven in this order, and the compartment 17a in the electric dust collecting unit A2 of the A series, The dust collecting electrodes 1 in the compartment 17b and the compartment 17c are beaten.

  After the strike of the dust collection electrode 1 in the A series electric dust collection units A1 and A2, the strike of the dust collection electrode 1 in the B series is performed. Since the strike of the dust collecting electrode 1 in the B series is the same as that in the A series, the description thereof is omitted.

  The time required for striking is about 30 minutes per room of the electrostatic precipitator 15. Therefore, the strike in the damper-linked strike requires about 1 hour per electric dust collection unit, and the entire system requires about 4 hours.

<Contents of coal property database>
FIG. 4 is an explanatory diagram showing the coal property database 51a. The coal property database 51a stores coal ash, sulfur, and the number of strikes in association with each other.
In the properties of the coal burned in the furnace 12 (see FIG. 1), the sulfur content and the ash content of the coal affect the dust collection performance.

Specifically, the higher the sulfur content, the lower the electrical resistivity (Ω · cm), and the higher the dust collection performance. This is due to surface conduction, and in the low temperature range, current easily flows on the surface of the particles due to adsorption of moisture and SO ₃ . The effect decreases with increasing temperature. However, since the electrostatic precipitator 15 in the present embodiment uses an apparatus called a low-temperature EP that operates by lowering the exhaust gas temperature, the sulfur content has a great influence on the dust collection performance. In particular, when coal with a total sulfur content of less than 0.40% is used, sparks are generated and EP current is reduced. For this reason, when using coal with a low total sulfur content, it is necessary to remove the dust adhering to a dust collection electrode reliably.

  Further, when the ash content increases, the dust concentration that cannot be collected by the electric dust collector 15 increases, so that the dust concentration in the outlet flue 21 increases. As the soot concentration increases, the number of sparks generated between the dust collection electrode 1 and the discharge electrode 2 also increases, and the EP current decreases. For this reason, even when using coal with high ash content, it is necessary to reliably remove the dust adhering to the dust collection electrode.

  The coal property database 51a associates the combination of the ash value and the total sulfur value of coal with whether the number of strikes in the damper-linked strike is one cycle or two cycles. Here, as described with reference to FIG. 2, one cycle refers to the period from the start of the damper-linked strike from the A series until the end of the B-series damper linked strike. Therefore, according to the present embodiment, it takes 4 hours per cycle.

  According to the coal property database 51a shown in FIG. 4, when the total sulfur content is lower than 0.25%, two cycles are associated regardless of the ash value. Further, when the total sulfur content is higher than 0.25%, either one cycle or two cycles is associated with the ash value. In FIG. 4, the range of the combination of ash and total sulfur set in one cycle is referred to as a damper-linked 1 cycle zone, and the range of the combination of ash and total sulfur set in 2 cycles is set to two cycles linked to a damper. It will be called a zone. In the damper-linked 1-cycle operation zone, a zone close to the damper-linked 2-cycle operation zone is referred to as a dust concentration caution zone.

  In this way, by obtaining the values of the ash content and total sulfur content of the coal burned in the furnace 12 (see FIG. 1), one cycle of the damper-linked strike is performed by referring to the coal property database 51a. It is possible to determine whether to perform two cycles.

<Driving control of dust collecting hammer>
Next, drive control of the dust collecting pole striker will be described with reference to FIG.
First, the worker examines in advance the ash value and the total sulfur value of the coal currently being burned in the furnace 12. Furthermore, the operator operates the operation unit 57 to register the coal ash value and the total sulfur value in the memory 51. Each time the type of coal burned in the furnace 12 changes, the value is registered in the memory 51 and the coal ash content and total sulfur content are updated.

  First, in step ST10, the CPU 53 obtains the presence / absence of a switching request for switching to the damper-linked strike, and if there is no switch request, the process proceeds to step ST12 to perform the interval strike. The striking devices 24a, 24b, 24c, 25a, 25b, 25c are controlled. The switch request to switch to the damper-linked strike is output from the timer 52 when the timer 52 has timed to switch to the preset damper-linked strike (for example, 0:00). In addition, the control device 55 obtains the dust concentration change rate from the detection result of the dust concentration detection device 44, and the switching request to switch to the damper-linked strike exceeds the threshold value set in advance. Is output if.

  In addition, when there is a switching request in step ST10, the CPU 53 shifts the process to step ST14 and performs the striking number setting process to set whether to perform the one-cycle operation or the two-cycle operation. The process shifts to ST16, and the dust collector striking device 24a, 24b, 24c, 25a, 25b, 25c is controlled to execute the damper interlocking striking. The details of the strike count setting process (step ST14) will be described later with reference to FIG.

  Further, the CPU 53 continues monitoring whether or not there is a switching request for switching to the damper-linked strike while executing the interval strike in step ST12 (step ST10).

  Then, when the set number of strikes is executed, the CPU 53 ends the damper linked strike (YES in step ST18), switches to the interval strike (step ST20), and proceeds to the process of step ST10.

  That is, the control device 55 mainly performs interval strikes during operation of the furnace 12, and when there is a request to switch to damper linkage strikes, the damper linkage strikes are performed in the cycle set in the process of step ST14. Run.

  According to the present embodiment, the switching request to switch to the damper-linked strike is output from the timer 52 when the timer 52 measures a preset damper-linked strike start time (for example, midnight). Or output from the operation unit 57 by an operation input of the operation unit 57 by a worker. In addition, the output method of the switching request | requirement switched to a damper interlocking strike is not restricted above.

<Strike count setting process>
Next, the striking number setting process in step ST14 shown in FIG. 5 will be described with reference to FIG.

  First, in step ST30, the CPU 53 (damper-linked strike count setting unit) determines whether or not it is currently between November and March. If it is between November and March, the strike count is set. As a result, two-cycle operation is set (step ST32). If it is not between November and March, the CPU 53 refers to the coal property database 51a in step ST34 (step ST34), and the combination of the value of total sulfur and the value of ash that is known in advance is 1 Determine whether you are in the cycle zone or the two-cycle zone.

  When the CPU 53 determines that the vehicle is in the 2-cycle zone (YES in step ST36), the 2-cycle operation is set as the number of strikes (step ST32). When the CPU 53 determines that it is in the dust concentration caution zone (YES in step ST38), the dust concentration monitoring setting is performed and the one-cycle operation is set as the number of strikes (step ST40 and step ST42). When the CPU 53 does not determine that it is in the dust concentration caution zone (NO in step ST38), in other words, when it is determined that it is in the one cycle zone, one cycle operation is set as the number of strikes (step ST42). ). When the process of step ST42 is completed, the CPU 53 shifts the process to the damper-linked strike (step ST16) of FIG.

  When the soot concentration monitoring setting is performed in step ST40, the change in the EP current, the soot concentration in the outlet flue 21 and the concentration increase rate are displayed on the monitor 58 in real time. The worker monitors the information displayed on the monitor 58 and, when it is determined to switch from the one-cycle operation to the two-cycle operation, operates the operation unit 57 and transmits a switching request to the control device 55. Alternatively, the control device 55 may compare the dust concentration and the concentration increase rate with a preset threshold value, and automatically execute the damper linked strike when the threshold value is exceeded.

  When performing 2-cycle operation, even if the second cycle starts immediately after the end of the first cycle, the second cycle starts after an interval after the end of the first cycle. Good. For example, after the end of the first cycle, the second cycle may be started after, for example, performing an interval beating for 8 hours. In this case, a damper-linked strike is carried out from midnight to 4 am, an interval strike is carried out from 4 am or midnight, and a damper-linked strike is carried out from 0 pm to 4 pm Interval strikes and damper linked strikes can be performed alternately at the same time interval, such as performing an interval strike until 4 pm or midnight. As described above, the timing of the implementation is not limited as long as the damper linked strike of two cycles per day is performed.

  According to the present embodiment configured as described above, since the number of strikes is set based on the ash content and total sulfur content of the coal burned in the furnace, for example, when the total sulfur content is small or the ash content is small If there are many, the number of strikes can be increased, and if the total sulfur content is large or the ash content is small, the number of strikes can be reduced. As a result, it is possible to reduce the need for damper-linked strikes or insufficient damper-linked strikes, and to properly perform damper-linked strikes.

  Further, according to the present embodiment, when the dust concentration and the concentration change rate exceed a preset threshold value, the interval dusting is switched to the damper interlocking hammering, so that the electric dust collector 15 is operated during the operation of the furnace 12. When there is a possibility that the dust collecting performance has deteriorated, it is possible to switch from the interval strike to the damper linked strike as necessary. This makes it possible to maintain the dust collection performance of the electric dust collector.

DESCRIPTION OF SYMBOLS 1 Dust collecting electrode 2 Discharge electrode 10 Pushing ventilator 11 Air preheater 12 Furnace 13 Exhaust gas denitration device 14 Heat recovery device 15 Electric dust collector 15a Case 15b Partition plate 16 First chamber 16a, 16b, 16c Partition chamber 17 Second chamber 17a, 17b, 17c Compartment room 18 Inlet flue 19, 20 Inlet damper 21 Outlet flue 22, 23 Outlet damper 24a, 24b, 24c Dust collector striker 25a, 25b, 25c Dust collector striker 30 Induction air Machine 32 Exhaust gas desulfurization device 35 Reheater 40 Chimney 41 Hopper 42 EP ash treatment device 43 Damper drive device 44 Dust concentration detection device 49 Inlet common damper 50 Control device 51 Memory 51a Coal property database 52 Timer 53 CPU
57 Operation section 55 Control device 58 Monitor 59 Exit common damper

Claims (2)

An electrostatic precipitator that removes soot in the exhaust gas from a furnace that burns coal;
A dust collector strike device installed in the electric dust collector;
An operation control device for controlling the dust collecting and punching device;
In a power plant operation system equipped with
The electric dust collector is
A case where exhaust gas circulates;
The inside of the case is partitioned into a plurality of compartments, each of which can be charged independently,
A dust collection electrode provided in each of the compartments for collecting the dust,
An inlet damper provided in the inlet flue of the case to control the flow of the exhaust gas;
An exit damper provided in the exit flue of the case,
The dust collecting electrode striking device strikes the dust collecting electrode,
The operation control device includes:
A coal property database for storing the coal ash content, total sulfur content, and the number of strikes;
In the state in which the inlet damper and the outlet damper are opened and the dust collecting electrode is charged, the collection is performed so that the interval beating repeatedly repeats the beating on the dust collecting electrode in the compartment. An interval hitting control unit for controlling the dust pole hitting device;
With the inlet damper and the outlet damper being closed and the dust collecting electrode being uncharged, the damper-linked hammering is performed so as to perform a hammering strike against the dust collecting electrode in the compartment. A damper interlocking hitting control unit for controlling the dust pole hitting device;
When switching from interval strikes to damper linked strikes, refer to the coal property database and set the number of strikes corresponding to the ash content and total sulfur content of the coal used in the current situation. A power plant operation system comprising: a setting unit; Further comprising a dust concentration detection device for detecting the concentration of dust in the exhaust gas discharged from the furnace,
The operation control device obtains the concentration change rate of the dust from the detection result of the dust concentration detection device, and when the dust concentration and the concentration change rate exceed a preset threshold value, from the interval strike to the damper linked strike. The power plant operation system according to claim 1, wherein the power plant operation system is switched.

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