JPH0664732U - Automatic intermittent power supply controller for electrostatic precipitator - Google Patents

Abstract

(57) [Abstract] [Objective] The automatic power supply control device for the electrostatic precipitator of the present invention is designed to detect turbidity of dust particles, turn on / off the electrification / non-conduction of the optimum level of DC power supplied to the electrostatic precipitator The purpose is to make a decision based on the energization parameter, reduce the human labor involved in the intermittent power supply control, and to automate the operation. In a configuration of an electrostatic precipitator that is activated / powered by DC power generated by rectifying means connected to an AC power supply, the magnitude of DC power is adjusted by adjusting the energized / de-energized period of the AC power supply. And a turbidity meter for detecting the turbidity of dust particles flowing through the electrostatic precipitator, and a turbidity level OPd detected by the dust particles flowing through the electrostatic precipitator. And CPU means for retrieving the lookup table based on.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention generally relates to an automatic intermittent power supply control device for use in an electrostatic precipitator.

[0002]

[Prior art]

 For the purpose of environmental protection, manufacturing equipment that generates exhaust gas is generally equipped with an electrostatic precipitator to collect suspended dust contained in the exhaust gas. A typical ESP includes a dust collecting plate arranged in parallel to each other and a discharge line arranged between the dust collecting plates. As is known as corona discharge, direct current power is supplied to the discharge line so that electrons discharged by the discharge line cause ionization of suspended dust passing through the ESP. The ionized dust particles are attracted by the electric field generated by the DC power, and are thus collected on the dust collecting plate.

Further, for the purpose of energy saving and high dust removal efficiency, the DC power supplied to the ESP may be changed according to the concentration of suspended dust passing through the ESP. That is, the direct current power is supplied at the maximum level when it is detected that the concentration of dust particles is extremely high, and the direct current power is reduced when it is detected that the flow rate of dust particles is low. be able to.

FIG. 4 is a configuration diagram of an intermittent power supply control device of an electrostatic dust collector according to a conventional example, and FIGS. 5A, 5B and 6 show an ESP power supply control device according to a conventional example. The AC signal waveform diagrams (Nos. 1 and 2) to be described are respectively shown. Fig. 5 (a) shows the AC voltage signal, and Fig. 5 (b) shows the AC voltage partially corresponding to the energized / non-energized pair (C, P) = (5, 1). The cleaved signal is shown, and FIG. 6 shows another signal in which the AC voltage is partially cleaved corresponding to the energized / non-energized pair (C, P) = (2, 5).

In FIG. 4, an AC power supply source 10 has a period T and is used as a main power supply source for generating an AC voltage V1 (t) of T = 1/60 in a general industrial power application. , Its waveform is shown in FIG. The thyristor circuit 20 is used in combination with the thyristor activation control circuit 30 to control passage or interruption of all sine wave cycles in the AC voltage V1 (t).

In the present discussion, the energization cycle will be defined as one cycle that can pass through the thyristor circuit 20 as one cycle including the first predetermined number C of all sinusoidal wave cycles in the AC voltage V1 (t). Further, the non-energization period that appears immediately after the end of one energization period is cut off by the thyristor circuit 20 as one period including the second predetermined number C of all sine wave periods in the AC voltage V1 (t). It is defined as one. Therefore, one energization period and the following one non-energization period alternately appear in the cycle of T1 + T2.

In the example shown in FIG. 5B, when (C, P) = (5,1), the entire sine wave period in the thyristor circuit V1 (t) is passed through this circuit five times in succession. Then, the subsequent cycle is cut off for a period of 6T. In another example, shown in FIG. 5 (c), if (C, P) = (2,5), the thyristor circuit 20 has two consecutive full sine wave cycles at V1 (t). Through and interrupt the following 5 cycles for a period of 7 · T.

Therefore, the entire sine wave period at V1 (t) is intermittently sent to the rectifier circuit 50 via the step-up transformer 40, and this circuit is used to generate a direct current output VDC proportional to the average power V2 (t). generate. According to the basic principle of electricity, the output DC voltage is also proportional to RC ', so that Rc' = C / C + P holds. When Rc is large, a large amount of electric energy is consumed, and when Rc is small, a small amount of electric energy is consumed.

The selection of the energized / non-energized parameter set (C, P) in the ESP power feeding control device according to the related art is performed only by manual input. Once selected, the control device cannot adapt to changes in the dust particle flow rate. The only way to change the DC power level input to the ESP is to manually enter another new set (C, P). Therefore, the ESP operator must stand by the ESP, monitor the dust particle flow rate, and thereby select the appropriate pair of parameters (C, P) for proper control of the dust removal process. is there.

[0010]

[Problems to be solved by the device]

 Therefore, a first object of the present invention is to provide an ESP power feeding control device having the ability to control the level of DC power supplied to the ESP device according to the flow rate of dust particles.

[0011]

[Means for Solving the Problems]

 The automatic intermittent power supply control device for an electrostatic precipitator of the present invention is activated / powered by DC power generated by a rectifying means connected to an AC power supply, as shown in FIGS. In the configuration of the electrostatic precipitator according to the present invention, it is a device for controlling the magnitude of the direct current power by adjusting the energized / non-energized period of the alternating current power supply, which is (a) the electrostatic precipitator. A turbidimeter for detecting the turbidity of the dust particles flowing through, and (b) CPU means for searching a reference table based on the turbidity level OPd detected in the dust particles flowing through the electrostatic precipitator. The reference table comprises a predetermined number of energized / de-energized periods for varying the DC power level, and the CPU means provides the difference between the detected turbidity level OPd and the initial turbidity level OPs. Is within the specified tolerance range Until it finds one value of the energization and non-energization period, and detects the optimum level of the DC power by relatively turbidity level OPd initial turbidity level OPs which, respectively it corresponds.

Further, in the automatic intermittent power supply control device for the electrostatic precipitator of the present invention, the reference table for the energized / non-energized period includes 20 items. Further, the automatic intermittent power supply control device for the electrostatic precipitator of the present invention is characterized in that the predetermined permissible range for the detected turbidity level OPd is -3≤OPd-OPs≤0.

In the automatic intermittent power supply control device for the electrostatic precipitator of the present invention, the CPU means detects dust particles flowing through the electrostatic precipitator after the optimum DC power is found. When the turbidity is continuously monitored and a difference is detected between the detected turbidity level and the default turbidity level that deviates from the predetermined permissible range, the CPU means returns to the above The above-mentioned object is achieved, which is characterized in that a reference table for energized / non-energized periods is searched.

[0014]

[Action]

 According to the automatic intermittent power supply control device of the electrostatic precipitator of the present invention, the turbidity meter and the CPU means are provided.

Therefore, it becomes possible to make the detected turbidity level of the dust particles passing through the electrostatic precipitator substantially equal to the predetermined turbidity level, and determine the optimum level of the DC power. It becomes possible.

That is, the turbidity meter attached to the ESP device detects the turbidity of the dust particles flowing therethrough, and the turbidity level is compared with a predetermined turbidity level by the CPU, and accordingly, the turbidity level is compared. The CPU searches a reference table having a large number of predetermined energization / de-energization parameter pairs.

This makes it possible to find one energization / de-energization parameter such that the detected turbidity level can fall within a predetermined range. As a result, compared to the conventional example, the human labor involved in the intermittent power supply control of the electrostatic precipitator is reduced, and the automation thereof is achieved.

[0018]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. 1 is a block diagram of an ESP automatic intermittent power supply control device according to an embodiment of the present invention, and FIG. 2 is a CPU control (main routine) flow chart of the ESP automatic power supply control device according to an embodiment of the present invention. is there.

The control (subroutine) flow charts of the CPU of the ESP automatic power supply control device according to the embodiment of the present invention are shown respectively. Further, in FIG. 1, the same reference numerals are assigned to the blocks that are not changed in the block diagram of the ESP intermittent power supply control device shown in the prior art.

That is, the automatic ESP intermittent power supply control device of the present invention includes the CPU 100 and the nephelometer 200 installed on the dust collecting plate of the ESP in FIG. The nephelometer 200 is a device that optionally includes a light beam emitting device and a light detecting device (neither shown), which is used to detect the turbidity of dust particles flowing through the ESP.

The light beam emitting device is used to emit a light beam, which flows through the path of the dust particles to the photodetector device, thereby actuating the photodetector device and causing dust inside the ESP. An electric signal OPd representing the detected turbidity of the flow rate is generated. The electric signal OPd is fed back to the CPU. When the concentration of dust particles is high, the photodetector detects a dim light beam, which produces a small current.

Further, when the concentration of dust particles is low, the photodetector detects a bright light beam, and thus a large current is generated. Therefore, the magnitude of the current generated by the photodetector can be used to indicate the opacity of the dust stream. The unit used to express opacity is called turbidity, where a high turbidity value indicates a high flow of dust particles and a low turbidity value indicates a low flow of dust particles.

Before entering the operation of the automatic ESP intermittent power supply control device, two predetermined constant parameters OPs and tR are manually input to the CPU 100. Where OPs is a predetermined value of the desired opacity for the dust stream and tR is the residence time of the dust stream in the ESP.

The function of the CPU 100 is to obtain the optimum value of the energized / non-energized group corresponding to the opacity OPd detected in the dust flow. When the optimum energized / non-energized combination is found, this is sent to the thyristor control circuit 40.

The flow of the program executed by the CPU 100 is shown in the control flow chart of FIG. In order to find the optimal energized / de-energized combination, a reference table search method is used to search from 20 predetermined energized / de-energized combinations. This includes the following combinations: (C0, P0) = (5,1), (C1, P1) = (4,1), (C2, P2) = (3,1), (C3, P3) = (5,2), (C4, P4) = (2,1), (C5, P5) = (4,2), (C6, P6) = (5,3), (C7, P7) = (3 , 2), (C8, P8) = (4,3), (C9, P9) = (5,4), (C10, P10) = (2,2), (C11, P11) = (3,3) ), (C12, P12) = (4,4), (C13, P13) = (5,5), (C14, P14) = (2,3), (C15, P15) = (3,4), (C16, P16) = (4,5), (C17, P17) = (3,5), (C18, P18) = (2,4), (C19, P19) = (2,5). When i <j, the energized / non-energized combination (Ci, Pi) supplies more DC power to the ESP than the energized / non-energized combination (Cj, Pj). The output energization / non-energization combination of the CPU 100 is represented by (Ccppt, Pcppt), where 0 ≦ CPPT ≦ 19.

At the beginning of the program, the CPU selects CPPT = 0, ie (Ccppt, Pcppt) = (C 0, P 0) = (5,1), as the output to the thyristor control circuit 30. The CPU 100 continuously executes the turbidity reading stage by the DC power operated at this energization / de-energization rate, and during this period, the CPU 100 continuously outputs the output of the turbidity meter 200 10 times at intervals of 2 seconds. Read, thereby collecting 10 detected turbidity readings. The 10 readings are then averaged to obtain OPd.

The value OPd is compared with the initial value OPs, and if the value OPd> OPs, high-concentration dust particles are still present in the ESP, so that the energized / de-energized parameter corresponding to CPPT = 0. The combination shows that it is not high enough for effective removal of dust particles.

Therefore, the AC output V1 (t) is transferred to the step-up transformer 40 and the rectifier circuit 50 without partial cutting (chopping), and the maximum DC power is supplied to the ESP. The full transfer of AC power lasts for 5 to 132 seconds. After this, the CPU 100 returns to the first stage of the program.

On the other hand, in the case of the value OPd <OPs, the dust particles of low flow rate exist in the ESP, and this causes more DC power than necessary during the energized / de-energized period corresponding to CPPT = 0. Indicates that As a result, the CPU 100 tries CPPT = 19, that is, uses (Ccppt, Pcppt) = (C19, P19) = (2,5) to activate the minimum DC power.

Using this combination of energized / non-energized parameters, the CPU 100 again reads the output of the turbidimeter 200 10 times at 2 second intervals, thereby collecting 10 turbidity readings. The 10 readings are then averaged to obtain a new OPd.

The new OPd is also compared with the initial value OPs. When OPd <OPs, it is shown that there is a very low flow rate of dust particles in the ESP. In this case, the energized / non-energized period corresponding to CPPT = 19 is maintained as an output from the CPU 100 to the thyristor start control circuit 30. At the same time, the CPU 100 displays (5, 2) on the display device 300 to provide the ESP operator with information.

On the other hand, when the value is OPd> OPs, it indicates that the optimum combination of energization / de-energization parameters (Ccppt, Pcppt) should exist somewhere between 0 and 19 in the coefficient CPPT. There is. FIG. 3 shows a control (subroutine) flowchart for detecting the optimum combination of energization / de-energization parameters.

Here, referring to FIG. 3, the CPU 100 tries a new combination of energization / de-energization parameters (Ccppt, Pcppt) with the CPPT value determined by the following calculation. CPPT = TRUNC (TOPINDEX / 2) TRUNC (TOPINDEX / 2) is an arithmetic operation that generates an integer value by rounding the addend part of the numbers in parentheses. TOPINDEX is an integer with an initial value of 19, which is the lowest CPPT value. Therefore, CPPT = 9 is selected and the turbidity reading step is performed again to obtain a new OPd which is compared to OPs.

In the preferred embodiment of the present invention, when OPd-OPs is in the range of -3 to 0, the current value of CPPT is optimum (Ccppt, Ccppt, which should be sent from the CPU 100 to the thyristor start control circuit 30). Pcppt) index is accepted.

Therefore, in the case of OPd−OPs ≦ −3, the optimum combination of energization / de-energization parameters (Ccppt, Pcppt) is that the CPPT coefficient does not exist anywhere from 0 to 9. Understand. In this case, the CPU 100 executes an arithmetic operation, that is, TOPINDEX = TOPINDEX-4, and TOPINDEX is changed from 19 to 15.

Further, as a result, CPPT = 7 is obtained in the next step. The CPU 100 repeats these steps until it finds one coefficient value CPPT that gives -3≤OPd-OPs≤0, and once the CPPT value is found, the CPU 100 causes the thyristor activation control circuit 30 to operate. (Ccppt, Pcppt) values are continuously transmitted and the values of CCPPT and PCPPT are displayed on the display device 200.

On the other hand, when OPd−OPs ≧ 0, it is understood that the optimum combination of energization / de-energization parameters should have a CPPT coefficient somewhere between (Ccppt, Pcppt) 11 and 18. . In this case, the CPU 100 executes the following arithmetic operation.

TOPINDEX = TOPINDEX + TRUNC (CPPT / 2) +1 This does not allow TOPINDEX to be changed from 19 to 24, and this also gives CP PT = 12 in the next step. The CPU 100 repeats these processing steps until it finds one coefficient value CPPT such that -3≤OPd-OPs≤0 is obtained.

Once the optimum CPPT value is found, the CPU 100 continues to send (Ccppt, Ccppt) corresponding to the optimum CPPT to the thyristor activation control circuit 30, and displays the values of CCPPT and PCPPT on the display device 200. To do.

After finding the optimum coefficient value CPPT for the combination of energized / de-energized parameters, the CPU 100 continues to monitor the turbidity of the dust stream. If the detected turbidity value OPd is outside the allowable range of -3≤OPd-OPs≤0, the CPU 100 executes the program from the first stage to select another optimum energization / non-energization parameter combination. Try to discover.

Although detailed above with exemplary preferred embodiments of the present invention, it should be understood that the scope of the present invention should not be limited to the disclosed preferred embodiments. Rather, it is intended to include various modifications and similar arrangements within the scope of the appended claims. The claims should be read as broadly as possible to encompass all such modifications and similar arrangements.

[0042]

[Effect of device]

 As described above, according to the automatic intermittent power supply control device of the electrostatic precipitator of the present invention, the turbidimeter for detecting the turbidity of the dust particles flowing through the electrostatic precipitator, and the electrostatic precipitator. CPU means for retrieving the reference table based on the turbidity level OPd detected in the dust particles flowing through the dust device.

Therefore, it is possible to make the detected turbidity level of the dust particles passing through the electrostatic precipitator substantially equal to the predetermined turbidity level, and determine the optimum level of the DC power. It becomes possible.

As a result, compared with the conventional example, the human labor involved in the intermittent power supply control of the electrostatic precipitator is reduced, and the automation thereof is achieved. This makes it possible to rationalize the dust removal process and improve the performance of the device.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an ESP automatic power supply control device according to an embodiment of the present invention.

FIG. 2 is a control (main routine) flowchart of the CPU of the ESP automatic power supply control device according to the embodiment of the present invention.

FIG. 3 is a control (subroutine) flowchart of the CPU of the ESP automatic power supply control device according to the embodiment of the present invention.

FIG. 4 is a configuration diagram of an intermittent power supply control device of an electrostatic dust collector according to a conventional example.

FIG. 5 is an AC signal waveform diagram (No. 1) for explaining an ESP power feeding control device according to a conventional example.

FIG. 6 is an AC signal waveform diagram (No. 2) for explaining an ESP power feeding control device according to a conventional example.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Zhang Suin, No. 195, 4th Section, Zhongxing Road, Zhongxing Town, Hsinchu County, Taiwan 64th Building, National Institute of Advanced Industrial Science and Technology

Claims (4)

[Scope of utility model registration request] 1. A structure of an electrostatic precipitator which is activated / powered by a DC power generated by a rectifying means connected to an AC power supply, wherein the DC power is adjusted by adjusting the energization / de-energization period of the AC power supply. A device for controlling the magnitude of electric power, comprising: (a) a turbidimeter for detecting the turbidity of dust particles flowing through the electrostatic precipitator; and (b) passing through the electrostatic precipitator. CPU means for retrieving a reference table based on the turbidity level OPd detected by flowing dust particles, the reference table comprising a predetermined number of energized / non-energized periods for varying the DC power level, Until the means finds one value of the energized / de-energized period such that the difference between the detected turbidity level OPd and the initial turbidity level OPs is within a predetermined allowable range, the corresponding turbidity is detected. Every time An automatic intermittent power supply control device for an electrostatic precipitator, characterized in that an optimum level of DC power is detected by making a level OPd and an initial turbidity level OPs face each other. 2. The reference table for the energized / non-energized period is 2
The automatic intermittent power feeding control device for an electrostatic precipitator according to claim 1, characterized in that it includes 0 items. 3. The electrostatic precipitator according to claim 1, wherein the predetermined permissible range for the detected turbidity level OPd is -3≤OPd-OPs≤0. Automatic intermittent power supply control device. 4. The CPU means continues to monitor the turbidity of dust particles flowing through the electrostatic precipitator after the optimum DC power is found, and the detected turbidity level and initial setting. When a difference between the turbidity level and the turbidity level is detected that deviates from the predetermined allowable range, the CPU means again searches the reference table of the energized / non-energized period. An automatic intermittent power supply control device for an electrostatic precipitator according to claim 1.