JP6526581B2 - Ozone generator and power supply - Google Patents

Description

  Embodiments of the present invention relate to an ozone generator and a power supply.

  In general, ozone generators are known as devices that generate strong residual ozone while generating less persistent ozone, and fields that require applications such as cleaning, sterilization, deodorization, decoloring, etc. while considering the environment (especially water treatment Are actively used in

  As a basic configuration of such an ozone generation apparatus, the raw material gas is flowed into the discharge gap formed between the dielectric electrode and the metal electrode, and a power supply is applied to the dielectric electrode, so as to be contained in the raw material gas. Is a mechanism to generate ozone by discharge at

Japanese Patent Application Laid-Open 10-182109 JP, 2013-193893, A

  By the way, in order to increase the amount of ozone generated by the ozone generator, a large capacity ozone generator provided with a plurality of metal electrodes and a plurality of dielectric electrodes is known. In the case of a large capacity ozone generator, when an abnormality occurs due to damage or the like of the dielectric electrode, a short circuit current flows from the normal dielectric electrode to the dielectric electrode in which the abnormality occurs. Therefore, in the case of a large capacity ozone generator, an overcurrent flows through the dielectric electrode where the abnormality occurs, and the fuse connected to the dielectric electrode is melted down to separate the dielectric electrode from the normal dielectric electrode. Can keep the device stable. However, in a small capacity ozone generator, it may not be sufficient to melt the fuse connected to the dielectric electrode in which an abnormality has occurred with only a short circuit current, and a stable ozone generator may not be able to operate. is there.

  The ozone generator of the embodiment includes a metal electrode, a plurality of dielectric electrodes, a fuse, and a power supply. The plurality of dielectric electrodes have discharge gaps between which the source gas is introduced and the metal electrodes, and are connected in parallel to one another. A fuse is provided for each dielectric electrode, and can cut off the flow of current to the dielectric electrode. The power supply device applies a power supply to the dielectric electrode and discharges the raw material gas to generate a power supply unit, and a break in which a current larger than the current flowing from the power supply unit to the dielectric electrode flows to the dielectric electrode The circuit has a first switch for connecting the dielectric electrode to the power supply unit or the fusing circuit, and when an abnormality occurs in the dielectric electrode, the first switch is controlled to cut the dielectric electrode into the fusing circuit. By connecting, the fuse of the dielectric electrode in which the abnormality has occurred is blown, and after the fuse is blown, the first switch is controlled to connect the dielectric electrode to the power supply unit.

FIG. 1 is a view showing an example of a schematic configuration of an ozone generator according to the present embodiment. FIG. 2 is a view showing an example of the electrical configuration of the ozone generator according to the present embodiment. FIG. 3 is a view showing an example of the fusing characteristics of the fuse included in the ozone generating apparatus according to the present embodiment. FIG. 4 is a view showing an example of the relationship between the capacitance and the constant of the capacitor of the ozone generation apparatus according to the present embodiment. FIG. 5 is a diagram showing an example of the characteristic of the fusing current flowing into the fuse of the dielectric electrode in which an abnormality has occurred in the ozone generation apparatus according to the present embodiment.

  Hereinafter, an ozone generator according to the present embodiment and a power supply device of the ozone generator according to the present embodiment will be described using the attached drawings.

  FIG. 1 is a view showing an example of a schematic configuration of an ozone generator according to the present embodiment. The ozone generator 10 is, for example, a dielectric barrier discharge type ozone generator. The ozone generator 10 concerning this embodiment has the ozone generator main body 11 and the storage container 12 which accommodates the said ozone generator main body 11 in an airtight state, as shown in FIG. The ozone generator main body 11 has a metal electrode 15, a dielectric electrode 16, a fixed electrode 17, and stainless steel wool 18, and a plurality of these are respectively installed.

  In the present embodiment, the metal electrode 15 is a cylindrical electrode. Specifically, the metal electrode 15 is, for example, an electrode made of stainless steel. Further, the metal electrode 15 has a closed space 21 into which cooling water is introduced on the inner peripheral surface side of the metal electrode 15. The dielectric electrode 16 has a predetermined discharge gap g between the metal electrode 15 and the source gas such as oxygen or dry air. The plurality of dielectric electrodes 16 are connected in parallel to one another.

  In the present embodiment, the dielectric electrode 16 is connected in parallel to another dielectric electrode 16 via the power line L connected to the commercial power supply C. Further, in the present embodiment, the dielectric electrode 16 is a cylindrical electrode coaxial with the metal electrode 15, and is connected to the power line L via the fixed electrode 17 provided on the inner peripheral surface side of the dielectric electrode 16. It is done. Further, in the present embodiment, the dielectric electrode 16 is connected to the fixed electrode 17 through the stainless steel wool 18 provided in at least a part of the gap between the dielectric electrode 16 and the fixed electrode 17. .

  Further, in the ozone generating apparatus main body 11, fuses 20 capable of cutting the flow of current to the dielectric electrode 16 are provided for each dielectric electrode 16. In the present embodiment, the fuses 20 are provided between the fixed electrode 17 provided on the inner peripheral surface side of each dielectric electrode 16 and the commercial power source C.

  The storage container 12 has a gas inlet side space 22 and a gas outlet side space 23. The gas inlet side space 22 and the gas outlet side space 23 are connected via a discharge gap g. In addition, the storage container 12 has a gas inlet 24 for introducing a source gas into the gas inlet side space 22. In addition, the storage container 12 has an ozonized gas discharge port 25 for discharging the gas (hereinafter referred to as ozone gas) flowing into the gas outlet side space 23 to the outside. Further, the storage container 12 has a cooling water inlet 26 for introducing the cooling water into the closed space 21 of the metal electrode 15 and a heat exchange with the metal electrode 15 to discharge the high temperature cooling water to the outside. And a cooling water outlet 27.

  In the above-described ozone generator 10, the source gas introduced into the gas inlet side space 22 therein flows into the discharge gap g. Next, a power supply (in the present embodiment, an AC power supply) is applied from the commercial power supply C to the dielectric electrode 16, and a dielectric barrier discharge is generated by the source gas flowing into the discharge gap g. As a result, oxygen molecules contained in the source gas flowing into the discharge gap g are dissociated into oxygen atoms, and other oxygen atoms are combined to generate ozone gas which ozonizes the source gas. Thereafter, the generated ozone gas flows out to the gas outlet side space 23 and is discharged from the ozonized gas outlet 25 to the outside.

  Further, in order to remove the heat generated in the metal electrode 15 by the dielectric barrier discharge, the cooling water is introduced into the closed space 21 from the outside through the cooling water inlet 26. Thereby, heat exchange is performed between the metal electrode 15 and the cooling water, and the metal electrode 15 is cooled. Thereafter, the cooling water which has become high temperature by heat exchange is discharged to the outside through the cooling water discharge port 27.

  Furthermore, when an abnormality occurs in the dielectric electrode 16 due to dielectric breakdown or the like, the fuse 20 provided between the dielectric electrode 16 and the commercial power source C by the short circuit current flowing in the dielectric electrode 16 in which the abnormality occurs. Is melted and the dielectric electrode 16 is separated from the other dielectric electrodes 16. As a result, it is possible to prevent the flow of charges charged in the discharge gap g between the normal dielectric electrode 16 and the metal electrode 15 with respect to the dielectric electrode 16 in which the abnormality has occurred. Even if an abnormality occurs in some of the dielectric electrodes 16 among 16, the dielectric barrier discharge can be generated between normal dielectric electrodes 16 and metal electrodes 15 to continue generation of ozone. .

  Next, an example of an electrical configuration of the ozone generator 10 according to the present embodiment will be described using FIG. 2.

  As shown in FIG. 2, the power supply device 30 included in the ozone generating apparatus 10 according to the present embodiment is a DC power supply of AC power of commercial power frequency supplied from a commercial power supply C (three phase AC power supply in the present embodiment). And an inverter 32 for converting DC power converted by the converter 31 into AC power of a predetermined frequency (for example, 1.0 to 5.0 kHz). Further, the power supply device 30 applies the alternating current power converted to a predetermined frequency by the inverter 32 to the dielectric electrode 16 through the transformer 33. In the present embodiment, the converter 31 and the inverter 32 function as an example of a power supply unit that generates ozone by applying a power to the dielectric electrode 16 and discharging the material gas.

  The equivalent circuit of the ozone generator 10 is a circuit in which a capacitance Cg corresponding to the dielectric electrode 16 and a capacitance Co corresponding to the discharge gap g are connected in series. Then, when the voltage Vo of the AC power supply applied to the discharge gap g (hereinafter referred to as the discharge gap voltage) exceeds a predetermined voltage Vs (hereinafter referred to as the discharge maintaining voltage), the source gas flowed into the discharge gap g Generate a dielectric barrier discharge. Since the dielectric barrier discharge has a constant voltage characteristic, the discharge gap voltage Vo is maintained at the discharge sustaining voltage Vs while the dielectric barrier discharge is generated. Thus, the equivalent circuit of the discharge gap g is represented by the Zener diode 34 having a breakdown voltage.

  As described above, since the discharge gap g functions as a capacitive load, the coil 35 is connected in series to the discharge gap g in order to make the power factor in the ozone generator 10 close to "1". In the present embodiment, in the ozone generator 10, the coil 35 is connected in series to the discharge gap g, but the invention is not limited to this. The coil 35 may be connected in parallel to the discharge gap g .

  Further, the power supply device 30 includes a fusing circuit 36 for supplying a current to the dielectric electrode 16, a switch SW1 (an example of a first switch) for connecting the dielectric electrode 16 to the power supply device 30 or the fusing circuit 36, and And 30, a control unit 37 that controls the operation of the entire system. When an abnormality occurs in the dielectric electrode 16, the control unit 37 controls the switch SW1 to connect the fusing circuit 36 and the dielectric electrode 16 and fuses the fuse 20 of the dielectric electrode 16 in which the abnormality occurs. A current is applied to blow the fuse 20. Here, the fusing current is a current that enables the fuse 20 to be fused, and is a current larger than the current flowing from the inverter 32 to the dielectric electrode 16. Then, the control unit 37 fuses the fuse 20 of the dielectric electrode 16 in which the abnormality has occurred, then controls the switch SW1 to connect the dielectric electrode 16 to the inverter 32, and restarts the generation of ozone. In the present embodiment, the control unit 37 detects the current value of the current flowing through the dielectric electrode 16, and when the detected current value reaches a predetermined value, an abnormality such as breakage occurs in the dielectric electrode 16 to decide.

  In the conventional ozone generator, when one dielectric electrode is damaged or the like, and an abnormality occurs, the current flowing to the dielectric electrode where the abnormality occurs is increased, the fuse is melted by the current, and the abnormality is It is possible to block the flow of current to the generated dielectric electrode. However, in a small-capacity ozone generator, since the current flowing to the dielectric electrode is small, when an abnormality occurs in the dielectric electrode, a fuse is used to cut the flow of the current to the dielectric electrode in which the abnormality occurs. It can not be melted and the voltage of other dielectric electrodes is lowered, which may lower the efficiency of ozone generation.

  On the other hand, in the ozone generating apparatus 10 according to the present embodiment, as described above, when an abnormality occurs in the dielectric electrode 16, the switch SW1 is controlled to connect the dielectric electrode 16 to the fusing circuit 36. The fusing circuit 36 can flow a large current to the fuse 20 as compared to the commercial power supply C, and therefore, the fuse 20 of the dielectric electrode 16 in which the abnormality has occurred is fused by certain means. Thus, even when the capacity of the ozone generator 10 is small, it is possible to separate the dielectric electrode 16 in which the abnormality has occurred. Therefore, it is possible to prevent the ozone generation efficiency from being lowered and operate the ozone generator stably. It can be realized.

  In the present embodiment, the fusing circuit 36 is provided between a power supply c (an example of a DC power supply) for flowing a current to the dielectric electrode 16, a capacitor Cc connected in parallel to the power supply c, and a power supply c and a capacitor Cc. And a switch SW2 (an example of a second switch) for connecting or disconnecting the power supply c and the capacitor Cc in parallel. When an abnormality occurs in the dielectric electrode 16, the fusing circuit 36 controls the switch SW2 to connect the power supply c and the capacitor Cc in parallel to charge the capacitor Cc. When the capacitor Cc is charged, the fusing circuit 36 causes a current to flow from the capacitor Cc and the power supply c to the dielectric electrode 16. Thereby, the fusing circuit 36 can fuse the fuse 20 in order to prevent the flow of the current to the dielectric electrode 16 in which the abnormality has occurred.

  In this embodiment, the voltage applied from the power supply c to the dielectric electrode 16 is the same as the voltage (for example, 10.0 kV) of the AC power supply voltage-converted by the transformer 33. The resistance value of the resistor Rc is determined by the charging time required to charge the capacitor Cc. The charging time is determined by the product of the capacitance of the capacitor Cc and the resistance value of the resistor Rc. For example, when the capacitance of the capacitor Cc is 3.6 μF and the resistance value of the resistor Rc is 160.0 kΩ, the charging time required to charge the capacitor Cc is 3.6 μF × 160.0 kΩ = 0.58 sec It becomes. The charging current I, which is a current flowing through the capacitor Cc, is a value obtained by dividing the voltage applied from the power supply c by the resistance value of the resistor Rc. For example, the charging current I is 10.0 kV / 160.0 kΩ = 63.0 mA.

  Next, with reference to FIG. 3, in the ozone generating apparatus 10 according to the present embodiment, the time required to melt the fuse 20 (hereinafter referred to as the melting time) and the current at which the fuse 20 is melted (hereinafter referred to as the melting current) The melting characteristics showing the relationship between The vertical axis in FIG. 3 represents the melting time, and the horizontal axis represents the melting current.

  As shown in FIG. 3, the melting characteristics of the fuse 20 are that the heat generation of the fuse 20 due to the flow of the melting current and the heat diffusion to the outside are on the long side (0.15 to 1000 sec) where the melting time is relatively long. It is stable, and the fusing current tends to change gradually. For example, when the fuse 20 is used for 10 years, the current flowing through the fuse 20 can be adjusted so that the fusing time is 100,000 hours or more. On the other hand, on the short side (0.1 to 0.00001 sec) where the fusing time is relatively short, the fuse 20 generates heat in a short time due to the flowing of the fusing current, so the fusing current tends to change rapidly. That is, the melting characteristics of the fuse 20 mean that the heat amount which the core wire of the fuse 20 is melted and the heat generation amount become equal in a short time, as the melting time becomes shorter.

According to the melting characteristics of the fuse 20 described above, the temperature rise of the core wire of the fuse 20 is represented by I 2 × R × t. Here, I is the fusing current, R is the resistance value of the core of the fuse 20, and t is the fusing time. Then, the constant H = I ^ 2 × t becomes constant. Therefore, the fusing time t is H × I ^ ² and has a slope of −2 with respect to the fusing current I. For example, in the fusing characteristics of the fuse 20 shown in FIG. 3, the fusing time t is 0.14 sec at the fusing current I = 10.0 A, so the slope of the fusing characteristics (that is, the constant H) is 10.0 ^ 2. × 0.14 = 14.0.

  FIG. 4 is a view showing an example of the relationship between the capacitance and the constant of the capacitor of the ozone generation apparatus according to the present embodiment. The vertical axis in FIG. 4 represents the constant H, and the horizontal axis represents the capacitance of the capacitor Cc. In general, when the constant H = I ^ 2 × t is expressed by an exponential function, it becomes 1 / (√3) × Io ^ 2 × tо. Here, Io is a peak value of the fusing current, and tо is a time constant (charging time determined by the product of the capacitance F of the capacitor Cc and the resistance value of the resistor Rc). Therefore, according to the relationship between the capacitance of the capacitor Cc and the constant H shown in FIG. 4, the fusing current Io is a value obtained by dividing the DC voltage DCV applied from the power supply c by the resistance value R. According to the above, the constant H is represented by the following equation (1). According to equation (1), the capacitor Cc is represented by the following equation (2).

したがって、Ｈ＝Ｉ＾２×ｔ＝１４．０の条件でヒューズ２０が溶断するため、コンデンサＣｃの静電容量は、３．６μＦ以上である必要がある。

Therefore, the fuse 20 is melted under the condition of H = I ^ 2 × t = 14.0, so the capacitance of the capacitor Cc needs to be 3.6 μF or more.

  FIG. 5 is a diagram showing an example of the characteristic of the fusing current flowing into the fuse of the dielectric electrode in which an abnormality has occurred in the ozone generation apparatus according to the present embodiment. The vertical axis in FIG. 5 represents the fusing current flowing from the capacitor Cc to the fuse 20 of the dielectric electrode 16 in which an abnormality has occurred, and the horizontal axis represents a flow in which the fusing current can flow from the capacitor Cc to the fuse 20 in the dielectric electrode 16 having the abnormality. Represents time. The elapsed time at the time of the peak (666.0 A) of the fusing current flowing into the fuse 20 is 54.0 μsec. If this is compared with the fusing characteristics of the fuse 20 shown in FIG. 3, the fuse 20 can be fused at a fusing current of 666.0 A and an elapsed time of 54.0 μsec.

  Therefore, the control unit 37 of the ozone generator 10 controls the switch SW1 to connect the fusing circuit 36 and the dielectric electrode 16 within several seconds after the occurrence of the abnormality of the dielectric electrode 16, and an abnormality occurs. In order to prevent the flow of current into dielectric electrode 16, fuse 20 is blown. Thereafter, the switch SW1 is controlled to reconnect the power supply 30 and the dielectric electrode 16 to resume the generation of ozone. As a result, the flow of current from the normal dielectric electrode 16 to the dielectric electrode 16 in which an abnormality has occurred can be prevented, so that the voltage of the normal dielectric electrode 16 is lowered to prevent the ozone generation efficiency from being lowered. Stable operation of the ozone generator can be realized.

  Thus, according to the ozone generator 10 concerning this embodiment, stable operation of the ozone generator can be realized.

  Although the embodiments of the present invention have been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. This embodiment is included in the scope and the gist of the invention, and is included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ozone generator 15 metal electrode 16 dielectric electrode 20 fuse 30 power supply 31 converter 32 inverter 36 fusion circuit c power supply Cc capacitor Rc resistance SW1, SW2 switch g discharge gap

Claims (6)

With metal electrodes,
A plurality of dielectric electrodes connected in parallel with each other and having discharge gaps between which the source gas flows and the metal electrodes;
A fuse provided for each of the dielectric electrodes and capable of cutting the flow of current into the dielectric electrodes;
A power supply unit that generates ozone by applying a power supply to the dielectric electrode and discharging it with the raw material gas, and a blowout that causes a current larger than the current flowing from the power supply unit to the dielectric electrode to the dielectric electrode A circuit and a first switch for connecting the dielectric electrode to the power supply unit or the fusing circuit, and when an abnormality occurs in the dielectric electrode, the first switch is controlled to perform the dielectric By connecting the body electrode to the fusing circuit, the fuse of the dielectric electrode where the abnormality has occurred is fused and the fuse is fused, and then the first switch is controlled to control the dielectric electrode as the power supply unit. A power supply connected to the
Ozone generator equipped with   The fusing circuit includes: a DC power supply for passing a current to the dielectric electrode; a capacitor connected in parallel to the DC power supply; a resistor connected between the DC power supply and the capacitor; And a second switch for connecting or disconnecting the capacitor in parallel, and controlling the second switch to connect the DC power supply and the capacitor in parallel to charge the capacitor, thereby charging the capacitor. The ozone generator according to claim 1, wherein current flows from the capacitor and the DC power supply to the dielectric electrode. The ozone generator according to claim 2, wherein the capacitance of the capacitor satisfies the following equation.

In the above equation, Cc is the capacitance, R is the resistance of the resistor, V is the voltage of the DC power supply, I is the current flowing from the DC power supply, and t is the fuse It is time to melt. A power supply unit that generates ozone by applying a power to a plurality of dielectric electrodes having discharge gaps into which a source gas flows in with the metal electrode and connected in parallel with each other to cause discharge with the source gas When,
A fusing circuit for causing a current larger than the current flowing from the power supply unit to the dielectric electrode to flow to the dielectric electrode;
A first switch connecting the dielectric electrode to the power supply unit or the fusing circuit;
When an abnormality occurs in the dielectric electrode, the flow of current to the dielectric electrode in which the abnormality occurs can be cut off by controlling the first switch to connect the dielectric electrode to the fusing circuit. A power supply apparatus, wherein a fuse is melted and the fuse is melted, and then the first switch is controlled to connect the dielectric electrode to the power supply unit.   The fusing circuit includes: a DC power supply for passing a current to the dielectric electrode; a capacitor connected in parallel to the DC power supply; a resistor connected between the DC power supply and the capacitor; And a second switch for connecting or disconnecting the capacitor in parallel, and controlling the second switch to connect the DC power supply and the capacitor in parallel to charge the capacitor, thereby charging the capacitor. The power supply device according to claim 4, wherein current flows from the capacitor and the DC power supply to the dielectric electrode. The power supply device according to claim 5, wherein the capacitance of the capacitor satisfies the following equation.

In the above equation, Cc is the capacitance, R is the resistance of the resistor, V is the voltage of the DC power supply, I is the current flowing from the DC power supply, and t is the fuse It is time to melt.

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