JP2021159912A - Power supply control system for electric dust collector, electric dust collector, and operation method thereof - Google Patents

Abstract

To enable complicated voltage control processing executed by a program to be executed at higher speed and with higher accuracy when an "IGBT power supply" is employed in an electric dust collector.SOLUTION: A power supply control system includes a power supply 21 and a control command transmitter 22. In the power supply control system 2 for an electric dust collector, the power supply 21 includes: a DC high voltage power supply 211 that includes an insulation gate bipolar transistor (IGBT); and a voltage control unit 212 that controls operation of the IGBT by a program. The control command transmitter 22 includes a program command generation unit 222 that converts a primary command into a command for program.SELECTED DRAWING: Figure 2

Description

The present invention relates to a power supply control system for an electrostatic precipitator, an electrostatic precipitator, and an operation method thereof. More specifically, the present invention provides a power supply control system for an electrostatic collector, which controls a DC high voltage power supply including an insulated gate bipolar transistor (IGBT) as a switching element, and such a system. It relates to an electric dust collector provided and an operation method thereof.

Conventionally, an electrostatic precipitator has been used for the purpose of collecting harmful dust and mist from waste gas generated in a waste incinerator process as well as sulfuric acid mist treatment and aluminum refining exhaust gas treatment (Patent Document 1). See ~ 3).

In such an electrostatic precipitator, it is required to improve the dust collection efficiency of dust containing heavy metals. As a general method for increasing the dust collection efficiency, a method is known in which the voltage between the dust collection electrode and the discharge electrode, that is, the voltage applied to the discharge electrode is set to a high voltage of a certain voltage or more (for example, 70 kV or more). ..

As a power source for the electrostatic collector operating at such a high voltage, a DC power source (hereinafter, also referred to as “IGBT power source” in the present specification) including an insulated gate bipolar transistor (IGBT) as a switching element can be preferably used. (See Patent Document 4).

However, at present, only the "IGBT power supply" has a built-in program for complicated control as a default configuration on the market, and the commands that can be input from an external device are very simple commands. In reality, it was limited to (for example, an alternative command for increasing or decreasing the voltage).

Based on the above facts, in an electrostatic precipitator equipped with an "IGBT power supply", for example, a process requiring complicated voltage control such as "intermittent charge processing" and "glow elimination processing" disclosed in Patent Document 4 is performed. It is still difficult to carry out with sufficient accuracy, and it has been regarded as a problem that various incidental effects that should be originally enjoyed cannot be fully enjoyed by adopting the "IGBT power supply".

Japanese Unexamined Patent Publication No. 2007-196159 Japanese Unexamined Patent Publication No. 2002-119889 Special Fair 6-91965 Gazette Japanese Unexamined Patent Publication No. 2020-11208

The present invention makes it possible to perform complicated voltage control processing executed by a program at higher speed and with higher accuracy when an "IGBT power supply" suitable as a DC high voltage power supply is adopted in an electrostatic precipitator. The purpose is.

The present inventor gives a primary command to be input to a voltage control program from the outside when an insulated gate bipolar transistor (IGBT) is used as a switching element constituting a DC high voltage power supply that generates a high voltage in an electrostatic dust collector. It was found that the above problem can be solved by newly introducing and arranging a control command transmitter having a function of converting to an appropriate language for the program as an external device separate from the IGBT type power supply in advance. , The present invention has been completed. Specifically, the present invention provides the following.

(1) A power supply control system for an electrostatic dust collector, comprising a power supply and a control command transmitter arranged apart from the power supply, the power supply being an insulated gate bipolar transistor (as a switching element). A DC high-voltage power supply equipped with an IGBT), a voltage control unit that controls the operation of the isolated gate bipolar transistor (IGBT) by a program, and a program command input unit that can input program commands in a program language from the outside. , The voltage control unit is installed with a program that executes voltage control according to the primary command input to the control command transmitter, and the control command transmitter can input the primary command. It has a primary command input unit, a program command generation unit that converts the primary command into the program command, and a program command output unit that outputs the program command to the program command input unit. , Power control system.

According to the invention of (1), when the "IGBT power supply" is adopted as the power supply of the electrostatic precipitator, the complicated voltage control process executed by the program can be performed at higher speed and with higher accuracy. be able to.

(2) The power supply control system according to (1), wherein the voltage control is a control for switching between continuous charge and intermittent charge for a charging method from the DC high voltage power supply.

According to the invention of (2), in the power supply control system of (1), a complicated voltage control process executed by a program for "intermittent charge processing", "glow elimination processing", etc. can be performed at higher speed. It can be done with higher accuracy.

(3) The power supply control system according to (2), wherein the voltage control is a control for changing a combination of a charge time and a non-charge time when the intermittent charge is performed.

According to the invention of (3), in the power supply control system of (2), complicated voltage control processing executed by a program for "intermittent charge processing", "glow elimination processing", etc. is further performed. It can be performed at high speed and with higher accuracy.

(4) An electrostatic precipitator comprising the power supply control system according to any one of (1) to (3).

According to the invention of (4), the characteristics of the "IGBT power supply" suitable for the high voltage power supply can be sufficiently brought out by enjoying the above-mentioned effect of the power supply control system according to any one of (1) to (3). However, it is possible to configure an electrostatic dust collector capable of performing complicated voltage control processing executed by a program for "intermittent charge processing", "glow elimination processing", and the like with sufficient accuracy.

(5) The operation of the electrostatic precipitator according to the operation method of the electrostatic precipitator according to (4), wherein the abnormal discharge erasing process is performed by the processing flow in which the following processes (i) to (iii) are sequentially performed. Method.
(I) When the value of the output voltage of the power supply becomes equal to or less than a predetermined threshold value, a low voltage detection signal is output.
(Ii) While the low voltage detection signal is being output, the control of shutting off the output from the power supply and then reapplying the output to the electrostatic precipitator main body is repeatedly executed at predetermined intervals.
(Iii) When the output of the low voltage detection signal starts, the timekeeping operation is started, and when the timekeeping time reaches the first predetermined time, an abnormal discharge erasing signal is output and the output of the power supply is completely cut off. Control is executed.

According to the invention of (5), in the electrostatic precipitator according to (4), by appropriately setting each of the above predetermined times, the dust collecting electrode of the electrostatic precipitator main body may be damaged due to the occurrence of a fire or the like. It is possible to stop the application of the output voltage V of the DC high-voltage power supply to the main body of the electrostatic precipitator before it is burnt out. In this way, damage or burning of the dust collecting electrode of the electrostatic precipitator main body is appropriately prevented, and eventually a fire of the electrostatic precipitator main body is appropriately prevented.

(6) The operation method of the electrostatic precipitator according to (5), wherein the abnormal discharge erasing process is performed by a process flow in which the following processes (iA) to (iiiA) are sequentially performed.
(IA) When the value of the output voltage of the power supply becomes equal to or less than a predetermined threshold value, a low voltage detection signal is output, and when the low voltage detection signal is output, the timer starts a timekeeping operation.
(IiA) When the time counting time by the timer elapses from the first predetermined time, an abnormal discharge erasing signal is output, and control is executed to completely shut off the output of the power supply. However, if the time for which the output voltage value of the power supply is restored to the predetermined threshold value or more continues for the second predetermined time or more while the time counting operation by the timer is continued, the time counting operation is stopped and the timer is stopped. Resets the time counting time to 0S.
(IiiA) When the recovery time is equal to or less than the second predetermined time, it is not regarded as recovery, the time counting operation is continued, and when the time counting time by the timer reaches the first predetermined time, an abnormality occurs. A discharge erasing signal is output, and control is executed to completely shut off the output of the power supply.

According to the invention of (6), in the electrostatic precipitator according to (5), based on the time when it can be determined that the abnormal discharge is eliminated and there is no risk of damage or burning of the dust collecting electrode of the electrostatic precipitator main body. By setting the second predetermined time, the above-mentioned fire or the like can be prevented from occurring, and erroneous detection of abnormal discharge can be prevented, and the output voltage V of the DC high-voltage power supply with respect to the main body of the electrostatic precipitator can be set. It is possible to avoid the necessary stoppage of application and to maintain better operating efficiency of the operation of the electrostatic precipitator main body while maintaining safety and stability.

(7) In the operation method of the electrostatic precipitator according to (5) or (6), all voltage control including voltage control for the abnormal discharge elimination process for the power supply is transmitted by the control command. How to operate the electrostatic precipitator by remote communication from the device.

According to the invention of (7), in the electrostatic precipitator according to (5) or (6), not only the abnormal discharge erasing process is controlled by an external signal from the control command transmitter, but also the electrostatic precipitator. It was decided to use a control flow in which all voltage control for the power supply of the device is performed by remote communication, and additional functions such as an abnormal discharge elimination processing function are added to a part of those controls. According to this, the response delay of the abnormal discharge erasing processing function can be further reduced, the operating speed can be made faster and faster, and the operating efficiency of the operation of the electrostatic precipitator main body can be further maintained.

According to the present invention, when an "IGBT power supply" suitable as a high voltage power supply is adopted as the power supply of the electrostatic precipitator, the complicated voltage control process executed by the program can be performed at higher speed and with higher accuracy. Can be done.

It is a block diagram which shows the structure of the electrostatic precipitator including the power supply control system for the electrostatic precipitator of this invention. It is a block diagram which shows the structure of the power-source control system for the electrostatic precipitator of this invention. It is a block diagram which shows the structure of the power-source control system for the conventional electrostatic precipitator. It is sectional drawing of the electric dust collector provided with the power control system for the electric dust collector of this invention. 1 (A) and 1 (B) are cross-sectional views taken from different directions substantially at right angles to each other. It is a perspective view which shows the structure inside the housing of the electrostatic precipitator main body which comprises the electrostatic precipitator of FIG. It is a partial cross-sectional view which shows the structure of the DC high voltage power source which comprises the electrostatic precipitator of FIG. 6 (A) and 6 (B) are cross-sectional views taken from different directions substantially at right angles to each other. It is an equivalent circuit diagram which shows the circuit structure of the power conversion circuit of the power source which constitutes the power source control system for the electrostatic precipitator of this invention.

<Electrostatic precipitator>
The electrostatic precipitator of the present invention can be configured by installing the power control system unique to the present invention on the main body of the electrostatic precipitator.

The electrostatic precipitator 10, which is one of the embodiments of the present invention, is used for the purpose of collecting harmful dust and mist contained as fine particles in various exhaust gases, like the conventional electrostatic precipitator. As shown in FIG. 1, the electrostatic precipitator 10 includes an electrostatic precipitator main body 1 and a power supply control system 2.

The main feature of the electrostatic precipitator 10 is that it includes a power supply control system 2 which is a power supply control system having a configuration different from that of the conventional one. By providing the power supply control system 2 in the electrostatic precipitator 10, complicated and highly accurate voltage control in the "IGBT power supply", which has been difficult to realize in the past, is realized.

[Electrostatic precipitator body]
The electrostatic precipitator main body 1 constituting the electrostatic precipitator 10 has an upper casing 11, a dust collecting electrode 12 that also functions as a side casing, a lower casing 13, and a frame 14. The upper casing 11, the dust collecting electrode 12, and the lower casing 13 are combined in this order from above to form a housing of the electrostatic precipitator main body 1. The housing of the electrostatic precipitator main body 1 is usually fixed by a frame 14 so as to be separated upward by a predetermined distance from the ground.

As a preferable example of the material of the housing of the electrostatic precipitator main body 1, conductive FRP (Fiber Reinforced Plastic) can be mentioned. In recent years, the waste gas to be treated by the electrostatic precipitator 10 may contain so-called corrosive substances such as hydrofluoric acid and sulfite gas in addition to harmful dust and mist. A conductive fiber-reinforced plastic is used instead of the conventional metal material as a material for forming a gas contact portion such as a casing of a dust device or a dust collecting electrode. By adopting FRP, it is possible to mainly enhance the corrosion resistance and to manufacture it at a lower cost than the highly corrosion resistant metal material.

As will be described in detail later, the electrostatic precipitator 10 can sufficiently prevent a fire from occurring due to spark discharge even during operation at a high voltage, and thus is conductive as a material of a member in contact with gas. It is easy to adopt sex FRP. As a result, corrosion of this portion is more reliably prevented, and as a result, the long-term durability of the electrostatic precipitator main body 1 can be improved.

Inside the housing of the electrostatic precipitator main body 1, as shown in FIG. 5, an upper grid 121, a dust collecting electrode 12, a lower grid 122, an electrode rod 123, a discharge line 124, a weight 125, an upward spray nozzle 126, and a cleaning nozzle are used. Piping 127 is provided. The upper grid 121, the dust collecting electrode 12, and the lower grid 122 are arranged so as to be substantially parallel to each other in the horizontal direction, separated from each other by a predetermined distance in that order from above.

As shown in FIG. 5, the dust collecting electrode 12 has a plurality of "chambers" repeatedly and continuously arranged with a square cylinder as a unit (in the present specification, such a unit is referred to as a "chamber"). It is composed of. Specifically, the dust collecting pole 12 is configured by repeatedly and continuously arranging N units in the vertical direction and repeatedly and continuously arranging M units in the horizontal direction (). In the present specification, one of the substantially horizontal directions is referred to as "vertical direction", and the direction perpendicular to this vertical direction is referred to as "horizontal direction"). Here, N and M are arbitrary integer values independent of each other, and as shown in FIG. 5, the number of “chambers” of the dust collecting pole 12 is N × M = 9 × 9. As the material of the dust collecting electrode 12, conductive FRP can be preferably used as described above. In this case, the dust collecting electrode 12 is composed of an aggregate of a plurality of the units, with a polygonal cylinder having an opening having a predetermined shape as a unit, and the discharge electrode is the unit of the plurality of units constituting the dust collecting electrode. It can be contained within each.

On the other hand, the release electrode is composed of an electrode rod 123 and a discharge line 124. As shown in FIG. 5, the electrode rod 123 is arranged so as to penetrate the central interior of a predetermined "chamber" of the dust collecting electrode 12 in a substantially vertical direction, and the upper end portion thereof is fixed to the upper grid 121. The lower end is fixed to the lower grid 122. As shown in FIG. 5, the discharge line 124 is suspended from the upper grid 121 and is arranged so as to penetrate the central interior of a predetermined “chamber” of the dust collecting electrode 12 in a substantially vertical direction. Further, the discharge line 124 is connected to a weight 125 provided on the upper part of the lower grid 122 so as to have a tension that does not loosen.

The DC high voltage of the negative electrode supplied from the DC high voltage power supply 211 constituting the power supply control system 2 is directly applied to the electrode rod 123. On the other hand, a high DC voltage of the negative electrode is applied to the discharge line 124 via the electrode rod 123 and the upper grid 121.

The upward spray nozzle 126 is arranged above the four corners of each "chamber" of the dust collecting electrode 12, and ejects the cleaning water flowing through the cleaning pipe 127 as a fine mist in a substantially vertical upward direction. This makes it possible to clean and remove fine particles such as mist and dust adhering to the dust collecting electrode 12.

[Power control system for electrostatic precipitators]
The details of the power supply control system 2 for the electrostatic precipitator, which can form the electrostatic precipitator 10 in combination with the electrostatic precipitator main body 1, will be described.

The power supply control system 2, which is also one of the independent embodiments of the present invention, is a power supply control system for an electrostatic precipitator, and includes a power supply 21 and a control command transmitter 22 as shown in FIG. Consists of.

Of the power supply 21 and the control command transmitter 22, which are the basic components of the power supply control system 2, the former power supply 21 is directly connected to the electrostatic precipitator main body 1 in a manner that substantially constitutes a part of the electrostatic precipitator main body 1. Or placed in close proximity to the electrostatic precipitator body 1. On the other hand, the latter control command transmitter 22 is arranged at a position at a certain distance from the electrostatic precipitator main body 1 and the power supply 21 as an external device for remotely controlling the electrostatic precipitator main body 1. In the power supply control system 2, since the two devices are arranged apart from each other in this way, complicated voltage control with high accuracy can be performed by remote control. The specific position of the control command transmitter 22 is not particularly limited, but from the viewpoint of ensuring the advantage of remote control, the distance between the electrostatic precipitator main body 1 and the power supply 21 is approximately 10 m or more. Is preferable.

(Power supply)
As shown in FIG. 2, the power supply 21 constituting the power supply control system 2 is a DC high-voltage power supply 211 including an insulated gate bipolar transistor (IGBT) as a switching element, and a voltage for controlling the operation of the insulated gate bipolar transistor (IGBT) by a program. It includes a control unit 212 and a program command input unit 213 capable of inputting a program command in a program language from the outside.

As an example, the DC high voltage power supply 211 includes a DC high voltage generating unit 211A and a DC high voltage input unit 211B, as shown in FIGS. 4 and 6. A DC high voltage of the negative electrode is applied to the electrode rod 123 constituting the discharge electrode of the electrostatic precipitator main body 1 from the DC high voltage power supply 211.

In the DC high voltage generator 211A, a series of processes such as boosting and rectifying the AC voltage supplied from the AC power supply (not shown in FIGS. 4 and 6; AC power supply 235 in FIG. 7) is executed. The high-voltage direct current obtained by this is output from the high-voltage output terminal 211C (FIG. 6).

The DC high voltage input unit 211B includes a bus duct 151 and an insulator chamber 153. Inside the bus duct 151, a bus bar 152, a wall-penetrating insulator 156, and a closing plate 157 are installed. A support insulator 158 is installed inside the insulator chamber 153.

The bus bar 152 connects one end of the protection resistor 154 (the end opposite to the end to which the high voltage output terminal 211C is connected) and one end of the wall-penetrating insulator 156. The wall-penetrating insulator 156 is arranged so as to penetrate the closing plate 157, one end thereof is connected to the bus bar 152, and the other end is connected to the support insulator 158 described later in the insulator chamber 153. .. The closing plate 157 is installed between the bus duct 151 and the insulator chamber 153 for the purpose of blocking the infiltration of the gas to be treated into the bus duct 151. One end of the support insulator 158 is connected to the wall-penetrating insulator 156 described above, and the other end is connected to the electrode rod 123 constituting the releasing electrode.

In the DC high voltage power supply 211 having the above configuration, the DC high voltage output from the high voltage output terminal 211C of the DC high voltage generation unit 211A is input to the DC high voltage input unit 211B, and the protection resistor 154, the bus bar 152, It is applied to the discharge electrode via the wall-penetrating porcelain 156 and the support porcelain 158. The protection resistor 154 is connected between the high voltage output terminal 211C and the bus bar 152 for the purpose of overvoltage protection.

FIG. 7 shows an equivalent circuit of the power conversion circuit constituting the DC high voltage power supply 211. As shown in the figure, in the power conversion circuit C1, the AC power supply 235, the input side rectifier 234, the switching element 233, the transformer 232, and the output side rectifier 231 are sequentially connected from the input side to the output side. In the power conversion circuit C1, the switching element 233 is an insulated gate bipolar transistor (IGBT). The insulated gate bipolar transistor (IGBT) is a power switching element that uses a MOSFET in the input section and a bipolar transistor in the output section. As long as it can correspond to the voltage assumed in the present application, it is not limited to a specific element, and various conventionally known IGBT elements can be appropriately used.

The power conversion circuit C1 is charged to switch the charging method for the electrostatic precipitator main body 1 from continuous charge to intermittent charge, for example, when the concentration of fine particles in the gas charged into the electrostatic precipitator main body 1 becomes a certain concentration or less. The method switching means 236 is installed.

Further, the power conversion circuit C1 is a high-voltage type power supply, but is characterized in that a capacitor for reducing the output voltage ripple is not installed.

The voltage control unit 212 is a control device that executes high-voltage DC voltage control output from the DC high-voltage power supply 211 in accordance with a primary command input to the control command transmitter 22 described later. The voltage control unit 212 controls the charging method to switch from continuous charging to intermittent charging, and controls to arbitrarily change the combination of charging time and non-charging time when intermittent charging is performed. In the power supply 21, such voltage control is performed by controlling the operation of the insulated gate bipolar transistor (IGBT) by a program installed in the voltage control unit 212.

The voltage control unit 212 operates the insulated gate bipolar transistor (IGBT) in accordance with a function of executing voltage control in the power supply 21, that is, a command (program command) in the program language input to the program command input unit 213. It is composed of an information processing device that can be controlled and a program for voltage control installed in the information processing device. The specific form of the voltage control unit 212 is not particularly limited. As an example, it may be incorporated in a power conversion circuit constituting the DC high voltage power supply 211, or as another example, it may be arranged outside the DC high voltage power supply 211 as an independent control device. It may be in a mode in which it is connected so as to be communicable.

The program command input unit 213 is installed in the voltage control unit 212 for the purpose of allowing the program command in the programming language output from the control command transmitter 22 to be input from the outside. The specific form of the connecting device having such a function is not particularly limited, and may be integrated as a part of the voltage control unit 212, for example.

(Control command transmitter)
As shown in FIG. 2, the control command transmitter 22 has a primary command input unit 223 capable of inputting a primary command (command) composed of a natural language that does not depend on the program language, and the primary command is described in a program command (described in the program language). The program command generation unit 222 that converts the command to the command) and the program command output unit 221 that outputs the program command to the program command input unit 213 provided in the power supply 21 are included. It is configured.

In the present specification, the "primary command" input to the primary command input unit 223 is a command (command) described in a natural language, a symbol, or the like before being translated into a programming language, or a "voltage Information related to control ", which is information that has not been translated into a programming language equivalent to those commands (commands). "Information related to voltage control" refers to information that should be reflected in voltage control, such as the concentration of a specific component in the exhaust gas discharged from the electrostatic precipitator main body 1.

The control command transmitter 22 is, for example, a general-purpose "control panel for the main body of the electrostatic precipitator" installed in an existing electrostatic precipitator, with necessary improvements, and each of the above-mentioned functions, that is, for a program. It can also be configured by adding all the functions to be fulfilled by the command output unit 221 and the program command generation unit 222, and the primary command input unit 223.

As described above, in the power supply control system 2B provided with the conventional "IGBT power supply", as shown in FIG. 3, a program command generation unit 222 necessary for executing a program is provided inside the power supply 21B. It is built-in, and a program command generation unit is not provided on the side of the control command transmission unit 22B. Due to this structure, in the power supply control system 2B provided with the conventional "IGBT power supply", it is difficult to execute complicated voltage control with high accuracy by an external operation. On the other hand, in the power supply control system 2, since the program command generation unit 222 is built in the control command transmitter 22 which is an external device, various primary commands can be input by remote operation. , More complicated voltage control can be executed at higher speed, higher accuracy, and by remote operation.

[Operation and operation method of electrostatic precipitator]
The basic operation and operation method of the electrostatic precipitator 10 having the above-described configuration will be described. In the electrostatic dust collector 10, the DC high voltage of the negative electrode generated from the DC high voltage generation unit 211A (FIGS. 4 and 6) is DC via the DC high voltage input unit 211B (FIGS. 4 and 6). A high voltage is applied to the discharge electrodes (electrode rod 123 and discharge line 124). Then, when the value of the DC high voltage rises, a negative corona discharge is generated between the discharge electrode and each side surface of the "chamber" of the dust collecting electrode 12 surrounding the discharge electrode, and as a result, dust is collected from the discharge electrode. Negative ions are transferred in the direction toward each side surface of the "chamber" of the pole 12, and ion wind is generated in the same direction.

As described above, in the electrostatic precipitator 10, the internal space of each "chamber" of the dust collecting electrode 12 becomes an ion space. Therefore, as shown in FIG. 4, the gas G1 containing fine particles such as mist and dust is supplied to the lower part of the housing of the electrostatic precipitator, and is supplied from the opening at the lower end of each "chamber" of the dust collector 12 to the upper end. When the particles flow toward the opening of the particle, the fine particles are charged by the collision of negative ions. The charged fine particles move by a direct current electric field inside each "chamber" of the dust collecting electrode 12 from the discharge electrode in a direction toward each of the side surfaces of each "chamber" of the dust collecting electrode 12 to collect the charged fine particles. It adheres to the side surface of each "chamber" of the dust electrode 12. In this way, the fine particles are removed from the gas G1. The gas G2 from which the fine particles have been removed from the gas G1 is discharged from the upper end of each "chamber" of the dust collecting electrode 12, and further, as shown in FIG. 4, from the upper part of the housing of the electrostatic precipitator of the present embodiment. It is discharged.

Here, in the electrostatic precipitator 10 which is a high voltage type electrostatic precipitator having an "IGBT power supply", the dust collection efficiency is improved by setting the charging voltage to a high voltage of, for example, about 70 kV or more. Can be done. However, it is not always economically preferable to continue to consume a large amount of electric power regardless of the concentration of fine particles contained in the exhaust gas to be treated. Therefore, from the viewpoint of energy saving, it is more preferable to variably control the charge voltage according to the concentration of fine particles in the exhaust gas in the high voltage type dust collector. As a result, it is possible to achieve power saving by suppressing an excessively applied DC high voltage, maintain dust collection efficiency, and achieve power saving.

Further, in the electrostatic precipitator 10 of the present invention, in the above-mentioned control of the charge voltage for energy saving, specifically, the concentration of fine particles in the gas charged into the electrostatic precipitator main body 1 becomes a certain concentration or less. In this case, it is more preferable that the charging method for the main body of the electrostatic precipitator is performed by a control method for switching from continuous charge to intermittent charge.

Further, in the electrostatic precipitator 10 capable of executing complicated voltage control with high accuracy and by remote operation, the electrostatic precipitator is changed from "abnormal discharge (mainly glow discharge which is a precursor of spark discharge)". The "abnormal discharge erasing process" for protecting the main body 1 can be executed with extremely high accuracy. This abnormal discharge erasing process can be performed by, for example, the following method.

The basic processing flow of the above-mentioned abnormal discharge erasing process in the electrostatic precipitator 10 is as follows (i) to (iii).
(I) When the value of the output voltage of the DC high voltage power supply 211 becomes equal to or less than a predetermined threshold value (for example, 24 kV), a low voltage detection signal is output.
(Ii) While the low voltage detection signal is being output, the control of shutting off the output from the DC high voltage power supply 211 and then re-inputting the output to the electrostatic precipitator main body 1 is repeatedly executed at predetermined intervals. (As an example, control that shuts off the output between 20 mS and then turns it on again every 450 mS).
(Iii) When the output of the above low voltage detection signal starts, the timekeeping operation is started, and when the timekeeping time reaches the first predetermined time (for example, 8S), the abnormal discharge erasing signal is output, and the timekeeping operation is started. As a result, control is executed to completely cut off the output of the DC high voltage power supply 211.

The electrostatic precipitator 10 further executes the processing according to the following processing flows (ia) to (iiiA) with extremely high accuracy in addition to the above processing as the processing flow for the abnormal discharge erasing process. Can be done.
(IA) A low voltage detection signal is output when the output voltage value of the DC high voltage power supply 211 is equal to or less than a predetermined threshold value (24 kV as an example), and a timer is output when the low voltage detection signal is output. Starts the timekeeping operation.
(IiA) When the time counting time by the timer elapses the first predetermined time (8S as an example), an abnormal discharge erasing signal is output, and as a result, the control that completely shuts off the output of the DC high voltage power supply 211 is performed. Will be executed. However, the time during which the output voltage value of the DC high-voltage power supply 211 recovers to a predetermined threshold value (24 kV as an example) or more while the timekeeping operation by the timer is continuing is a second predetermined time (600 mS as an example). ) If it continues for more than that, the time counting operation is stopped and the time counting time by the timer is reset to 0S.
(IiiA) When the above-mentioned "recovering time" is less than or equal to the above-mentioned second predetermined time (600 mS as an example), it is not regarded as recovery, the time counting operation is continued, and the time counting time by the timer is the predetermined time. (As an example, 8S), an abnormal discharge erasing signal is output, and as a result, control is executed to completely cut off the output of the DC high-voltage power supply 211.

The electrostatic dust collector 10 of the present invention employs a power supply control system 2 having a configuration in which the power supply 21 and the control command transmitter 22 are separated from each other as the power supply control means. The configuration is provided with a program command generator that converts the primary command into the program command. As a result, it is possible to control the operation of the switching element of the "IGBT power supply" in a more complicated, high-speed and highly accurate output voltage control than the conventional "IGBT power supply" having a built-in program command generator. became.

For example, in order to properly execute the above-mentioned "abnormal discharge elimination" process according to the performance and operating conditions of the electrostatic collector main body, high-precision control with an extremely short reaction time to the command is essential, but for programming. In the conventional "IGBT power supply" with a built-in command generator, the types of commands that can be input to the power supply are fixed, complicated, and high-precision control with a short reaction time to commands can be sufficiently performed. In many cases, it was not. On the other hand, in the electrostatic precipitator 10 of the present invention, the degree of freedom of the commands that can be input is large because the external device for inputting the primary command is provided with the command generator for the program. As described above, it has become possible to control the output voltage more complicatedly, at higher speed, and with higher accuracy because fine adjustment can be performed by remote operation from the power supply.

Further, in the above-mentioned conventional "IGBT power supply", the intermittent charge switching operation for the "abnormal discharge elimination" process has a response delay of about 2.5 seconds at the start of the operation, and is switched between charged and uncharged. As for the operation interval, switching in units of 1 second was the upper limit of the switching speed. On the other hand, in the electrostatic precipitator 10 of the present invention, not only the abnormal discharge erasing process is controlled by an external signal from the control command transmitter, but also all voltage control for the power supply of the electrostatic precipitator is performed. According to the control flow in which the above-mentioned response delay is eliminated and the switching operation interval is ON / The switching speed can be improved to 200 msec OFF. In this case, for example, by enabling charge control at the above switching speed, the number of return trials for normal charging is 12 times in the time from low voltage detection to cutoff (8 seconds), and the electrostatic precipitator main body has. An extremely preferable operation as an operation mode for the "abnormal discharge elimination" process becomes possible.

The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the range in which the object of the present invention can be achieved are included in the present invention. For example, in the DC high-voltage power supply 211, the main part can be configured by a single piece of hardware (circuit) as described above, but the present invention is not limited to this, and any part or the whole may be configured by software. good. When a series of processes are executed by software, the programs constituting the software are installed on a computer or the like from a network or a recording medium. The computer may be a computer embedded in dedicated hardware. Further, the computer may be a computer capable of executing various functions by installing various programs, for example, a general-purpose personal computer.

1 Electrostatic precipitator body 11 Upper casing 12 Dust collector pole (side casing)
121 Upper grid 122 Lower grid 123 Electrode rod 124 Discharge line 125 Weight 126 Upward spray nozzle 127 Cleaning piping 13 Lower casing 14 Frame 151 Bus duct 152 Bus bar 153 Busbar chamber 154 Protective resistance 156 Wall-penetrating transformer 157 G Exhaust gas contained G2 Exhaust gas from which dust has been removed 2 Power supply control system 21 Power supply 211 DC high voltage power supply 211A DC high voltage generator 211B DC high voltage input unit 211C High voltage output terminal 212 Voltage control unit 213 Program command input unit 22 Control Command transmitter 221 Program command output unit 222 Program command generator unit 223 Primary command input unit 224 Command input unit 225 Command output unit 231 Output side rectifier 232 Transformer 233 Switching element (IGBT)
234 Input side rectifier 235 AC power supply 236 Charging method switching means C1 Power conversion circuit 10 Electrostatic precipitator

Claims (7)

A power control system for electrostatic precipitators
A power supply and a control command transmitter arranged apart from the power supply are provided.
The power supply
A DC high-voltage power supply equipped with an insulated gate bipolar transistor (IGBT) as a switching element,
A voltage control unit that controls the operation of the insulated gate bipolar transistor (IGBT) by a program,
It is equipped with a program command input section that allows you to input program commands in a programming language from the outside.
The voltage control unit has a program installed that executes voltage control according to the primary command input to the control command transmitter.
The control command transmitter has a primary command input unit capable of inputting the primary command, a program command generation unit that converts the primary command into the program command, and the program command input unit. Has a command output unit for programs that outputs to
Power control system. The voltage control is a control for switching between continuous charge and intermittent charge for the charging method from the DC high voltage power supply.
The power control system according to claim 1. The power supply control system according to claim 2, wherein the voltage control is a control for changing a combination of a charge time and a non-charge time when the intermittent charge is performed. An electrostatic precipitator comprising the power supply control system according to any one of claims 1 to 3 and an electrostatic precipitator main body. The method of operating the electrostatic precipitator according to claim 4.
An operation method of an electrostatic precipitator that performs an abnormal discharge erasing process according to a process flow in which the following processes (i) to (iii) are sequentially performed.
(I) When the value of the output voltage of the power supply becomes equal to or less than a predetermined threshold value, a low voltage detection signal is output.
(Ii) While the low voltage detection signal is being output, the control of shutting off the output from the power supply and then reapplying the output to the electrostatic precipitator main body is repeatedly executed at predetermined intervals.
(Iii) When the output of the low voltage detection signal starts, the timekeeping operation is started, and when the timekeeping time reaches the first predetermined time, an abnormal discharge erasing signal is output and the output of the power supply is completely cut off. Control is executed. The operation method of the electrostatic precipitator according to claim 5, wherein the abnormal discharge erasing process is performed by a processing flow in which the following processes (iA) to (iiiA) are sequentially performed.
(IA) When the value of the output voltage of the power supply becomes equal to or less than a predetermined threshold value, a low voltage detection signal is output, and when the low voltage detection signal is output, the timer starts a timekeeping operation.
(IiA) When the time counting time by the timer elapses from the first predetermined time, an abnormal discharge erasing signal is output, and control is executed to completely shut off the output of the power supply. However, if the time for which the output voltage value of the power supply is restored to the predetermined threshold value or more continues for the second predetermined time or more while the time counting operation by the timer is continued, the time counting operation is stopped and the timer is stopped. Resets the time counting time to 0S.
(IiiA) When the recovery time is equal to or less than the second predetermined time, it is not regarded as recovery, the time counting operation is continued, and when the time counting time by the timer reaches the first predetermined time, an abnormality occurs. A discharge erasing signal is output, and control is executed to completely shut off the output of the power supply. The method of operating the electrostatic precipitator according to claim 5 or 6.
All voltage control of the power supply, including voltage control for the abnormal discharge elimination process, is performed by remote communication from the control command transmitter.
How to operate the electrostatic precipitator.

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