Ozone generation device and ozone generation method

Abstract

The purpose of the present disclosure is to provide a structure of an ozone generation device that is capable of generating a relatively high concentration of ozone gas while suppressing a refrigerant amount of a refrigerant to a minimally needed amount. In an ozone generation device according to the present disclosure, raw material gas (G1) is supplied from the entire periphery of an electric discharge space (6) toward the center, and ozone gas (G2) obtained in the electric discharge space (6) is output from an electric discharge central space (S1) to the outside via a gas outflow port (12). A refrigerant flow path (4) provided in a low-voltage electrode (1) has a center-priority refrigerant flow path structure in which a refrigerant (C1) is made to flow in an electrode center region (D1) prior to in an electrode peripheral region (D2), by causing the refrigerant (C1) to flow from a refrigerant inlet (4a) toward a refrigerant outlet (4b).

Description

Ozone generator and ozone generation method

[0001] The present disclosure relates to an ozone generator having an electrode structure including first and second flat metal electrodes, and an ozone generation method.

[0002] Conventional ozone generators include an ozone generator having an electrode structure including first and second flat metal electrodes, such as that disclosed in Patent Document 1.

[0003] The ozone generator disclosed in Patent Document 1 includes a flat low-voltage electrode, a flat high-voltage electrode facing a main surface of the low-voltage electrode, a flat dielectric provided between the low-voltage electrode and the high-voltage electrode, and a spacer for forming a discharge space having a small thickness in the stacking direction. An ozone gas passage is provided in the low-voltage electrode.

[0004] The oxygen gas used as the source gas flows from the periphery to the center of the discharge space, where it is generated as ozone gas (ozonized oxygen gas), which is then output to the outside via an internal ozone gas passage. Meanwhile, a cooling water passage is provided in the low-voltage electrode, and cooling water, which acts as a refrigerant, is passed through the cooling water passage to lower the gas temperature in the discharge space.

[0005] Japanese Patent Application Laid-Open No. 2003-160312

[0006] Conventional ozone delivery devices, such as the ozone generator disclosed in Patent Document 1, lower the gas temperature in the discharge space by providing a refrigerant flow path (cooling water passage) through which a refrigerant (cooling water) flows in the low-voltage electrode.

[0007] However, as the coolant flow path provided in the low-voltage electrode, a plurality of partial coolant flow paths are provided, each of which is provided along the circumferential direction within the low-voltage electrode, and the coolant flows through each of the plurality of partial coolant flow paths.

[0008] As described above, the coolant flow paths provided in the electrodes of conventional ozone generators are designed to lower the gas temperature throughout the discharge space, and therefore the amount of coolant used is not optimized, and the ozone concentration of the generated ozone gas is not optimally increased.

[0009] An object of the present disclosure is to provide an ozone generator and an ozone generation method that can solve the above-mentioned problems and generate relatively high-concentration ozone gas while minimizing the amount of refrigerant used.

[0010] The ozone generator of the present disclosure comprises a flat first metal electrode and a flat second metal electrode arranged opposite the first metal electrode, at least one of the first and second metal electrodes having a gas outlet at a center thereof, and further comprising at least one electrode dielectric provided adjacent to at least one of the first and second metal electrodes between the first and second metal electrodes, a discharge space being provided between the first and second metal electrodes in contact with the at least one electrode dielectric, a voltage being applied between the first and second metal electrodes to generate a dielectric barrier discharge in the discharge space, a raw material gas being supplied to the discharge space, and ozone gas being obtained by the raw material gas passing through the discharge space in which the dielectric barrier discharge is generated, and the discharge space is the discharge central space communicates with the gas outlet, and a discharge peripheral space exists around the discharge central space, the source gas is supplied from the discharge peripheral space toward the discharge central space, at least one of the first and second metal electrodes is a flow path-integrated metal electrode, the flow path-integrated metal electrode has an electrode central region overlapping with the discharge central space in a planar view, and an electrode peripheral region overlapping with the discharge peripheral space in a planar view, the flow path-integrated metal electrode has a refrigerant flow path through which a refrigerant flows inside, the refrigerant flow path is formed from the electrode central region to the electrode peripheral region, the ozone gas obtained in the discharge space is output from the discharge central space to the outside via the gas outlet, and the refrigerant flow path has a center-priority refrigerant flow path structure that causes the refrigerant to flow to the electrode central region before the electrode peripheral region.

[0011] In the ozone generator of the present disclosure, the coolant flow path provided in the flow path-integrated metal electrode has the above-mentioned center-priority coolant flow path structure, so that the temperature of the central region of the electrode close to the gas outlet can be kept relatively low. On the other hand, since the source gas is supplied from the peripheral discharge space toward the central discharge space, the ozone concentration in the central discharge space tends to be higher than the ozone concentration in the peripheral discharge space with respect to the ozone gas generated in the discharge space.

[0012] Therefore, the ozone generator of the present disclosure can generate relatively high-concentration ozone gas by minimizing the amount of refrigerant used by the refrigerant flow path provided in the flow path-integrated metal electrode to have the above-mentioned center-priority refrigerant flow path structure, thereby enhancing the cooling effect in the central discharge space.

[0013] The objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description and the accompanying drawings.

[0014] FIG. 1 is an explanatory diagram schematically showing the principle of an ozone generator. FIG. 1 is an explanatory diagram schematically showing the cross-sectional structure of an electrode unit, which is a basic configuration of embodiment 1. FIG. 2 is an explanatory diagram schematically showing the planar structure of a refrigerant flow path of a low-voltage electrode in a first aspect of embodiment 1. FIG. 3 is an explanatory diagram schematically showing a discharge space on the low-voltage electrode shown in FIG. 3. FIG. 4 is an explanatory diagram (part 1) schematically showing the cross-sectional structure of the low-voltage electrode shown in FIG. 3. FIG. 5 is an explanatory diagram (part 2) schematically showing the cross-sectional structure of the low-voltage electrode shown in FIG. 3. FIG. 6 is an explanatory diagram schematically showing the planar structure of a refrigerant flow path of a low-voltage electrode in a second aspect of embodiment 1. FIG. 7 is an explanatory diagram (part 1) schematically showing the cross-sectional structure of the low-voltage electrode shown in FIG. 7. FIG. 7 is an explanatory diagram (part 2) schematically showing the cross-sectional structure of the low-voltage electrode shown in FIG. 19 is an explanatory diagram (part 2) schematically showing the cross-sectional structure of the ozone gas generation unit shown in FIG. 10 . FIG. 19 is an explanatory diagram (part 1) schematically showing the planar structure of the refrigerant flow path of the low-voltage electrode in the fourth aspect of embodiment 1. FIG. 19 is an explanatory diagram (part 2) schematically showing the planar structure of the refrigerant flow path of the low-voltage electrode in the fourth aspect of embodiment 1. FIG. 19 is an explanatory diagram (part 1) schematically showing the planar structure of the refrigerant flow path of the low-voltage electrode in the fourth aspect of embodiment 1. FIG. 19 is an explanatory diagram (part 2) schematically showing the planar structure of the low-voltage electrode in the first aspect of embodiment 3. 23 is an explanatory diagram showing a cross-sectional structure of an electrode unit according to a fourth embodiment of the present invention;

[0015] <Principle of the Present Disclosure> Figure 1 is an explanatory diagram that schematically illustrates the principle of the ozone generator of the present disclosure. The figure shows an electrode internal region R1 of a channel-integrated metal electrode having a refrigerant channel therein. The channel-integrated metal electrode corresponds to at least one of first and second flat metal electrodes.

[0016] A refrigerant C1 is supplied from an external refrigerant supply flow path 31 to the electrode internal region R1 of the flow path-integrated metal electrode through a refrigerant supply port 21, and after the refrigerant C1 is supplied into the electrode internal region R1, it is discharged to an external refrigerant discharge flow path 32 through a refrigerant discharge port 22.

[0017] By applying an AC voltage between the first and second metal electrodes, a dielectric barrier discharge can be generated in the discharge space 6. Here, it is assumed that the space above the electrode internal region R1 shown in FIG.

[0018] When a dielectric barrier discharge is generated in the discharge space 6, if a source gas G1 such as oxygen gas is supplied from the entire periphery of the discharge space 6 toward the center of the discharge space 6, ozone gas G2 can be obtained from the source gas G1 in the discharge space 6. The generated ozone gas G2 is output to the outside through a gas outlet 12 provided so as to penetrate the center of the electrode internal region R1.

[0019] As described above, the electrode internal region R1 is cooled because the refrigerant C1 is supplied to the electrode internal region R1. For example, if the temperature distributions T(0) to T(8) caused by the refrigerant C1 exist concentrically around the gas outlet 12 as shown in Figure 1, it is desirable to make the temperature distributions T(0) to T(2) in the central discharge space closest to the gas outlet 12 the lowest.

[0020] This is because the ozone gas G2 generated in the discharge space 6 has the highest ozone concentration in the discharge central space of the discharge space 6, and therefore it is necessary to lower the temperature in the discharge central space to prevent the ozone gas G2 in a high ozone concentration state from being decomposed.

[0021] Ideally, the temperature distribution T(0) is the lowest and the temperature distribution T(8) is the highest, and it is desirable that T(k) < T(k+1) holds when k = 0 to 7. By setting such temperature distributions T(0) to T(8), it is expected that the amount of refrigerant C1 supplied to the electrode internal region R1 can be kept to a necessary minimum, thereby generating a relatively high concentration of ozone gas G2.

[0022] <First Embodiment> (Basic Configuration) Fig. 2 is an explanatory diagram schematically showing the cross-sectional structure of an electrode unit 61, which is the basic configuration of a first embodiment of the present disclosure. An ozone generator including the electrode unit 61 is the ozone generator of the first embodiment. An XYZ Cartesian coordinate system is depicted in Fig. 2. As shown in Fig. 2, the electrode unit 61 includes electrode components E1 and E2 and a spacer 7 as main components.

[0023] The electrode configuration part E1 includes, as a main component, a low-voltage electrode 1. The low-voltage electrode 1, which is a flat first metal electrode, has a gas outlet 12 that penetrates the center as a gas outlet provided in the center.

[0024] An electrode configuration E2 is provided on the low-voltage electrode 1 of the electrode configuration E1 via a spacer 7. The electrode configuration E2 includes a high-voltage electrode 2 and a dielectric 3 as its main components. The dielectric 3, which serves as an electrode dielectric, is formed on the lower surface of the high-voltage electrode 2, which is a flat-plate-shaped second metal electrode. The dielectric 3 is formed as a thin film.

[0025] In this manner, the high-voltage electrode 2, which serves as a flat-plate second metal electrode, is disposed opposite the low-voltage electrode 1, which serves as a flat-plate first metal electrode. A discharge space 6 is provided between the low-voltage electrode 1 and the high-voltage electrode 2, in contact with the dielectric 3.

[0026] 2, dielectric 3 serving as the electrode dielectric is provided adjacent to high-voltage electrode 2, but it may also be provided adjacent to low-voltage electrode 1. In other words, it is sufficient to provide at least one electrode dielectric between low-voltage electrode 1 and high-voltage electrode 2, adjacent to at least one of low-voltage electrode 1 and high-voltage electrode 2.

[0027] However, it is necessary that the discharge space 6 be provided in contact with at least one electrode dielectric between the low-voltage electrode 1 and the high-voltage electrode 2. In other words, when forming an electrode dielectric in the electrode configuration portion E1, it is necessary to provide the electrode dielectric on the upper surface of the low-voltage electrode 1.

[0028] 2, a dielectric barrier discharge can be generated in the discharge space 6 by applying an AC voltage between the low-voltage electrode 1 and the high-voltage electrode 2. For example, an AC voltage is applied to the high-voltage electrode 2, and the low-voltage electrode 1 is set to a reference voltage such as ground voltage.

[0029] The discharge space 6 includes a central discharge space S1 communicating with the gas outlet 12 and a peripheral discharge space S2 existing around the central discharge space S1.

[0030] 2, a source gas G1 such as oxygen gas is supplied from the entire periphery toward the center of the discharge space 6. That is, the source gas G1 is supplied from the discharge peripheral space S2 toward the discharge central space S1. Ozone gas G2 is obtained by passing the source gas G1 through the discharge space 6 where a dielectric barrier discharge is generated.

[0031] The ozone gas G2 obtained in the discharge space 6 is discharged from the discharge central space S1 to the outside via the gas outlet 12.

[0032] The low-voltage electrode 1 functions as a flow path-integrated metal electrode and has a refrigerant flow path 4 therein through which a refrigerant C1 flows. The low-voltage electrode 1, which functions as a flow path-integrated metal electrode, has an electrode central region D1 that overlaps with the discharge central space S1 in a planar view, and an electrode peripheral region D2 that overlaps with the discharge peripheral space S2 in a planar view in the XY plane. Note that cooling water, for example, can be used as the refrigerant C1.

[0033] The refrigerant flow path 4 provided in the low-voltage electrode 1 has a refrigerant inlet 4a in a central region on the underside of the low-voltage electrode 1 and a refrigerant outlet 4b on a side surface of the low-voltage electrode 1, and is formed from the electrode central region D1 to the electrode peripheral region D2. The refrigerant flow path 4 provided in the low-voltage electrode 1 has a center-priority refrigerant flow path structure in which the refrigerant C1 flows from the refrigerant inlet 4a toward the refrigerant outlet 4b, thereby causing the refrigerant C1 to flow to the electrode central region D1 before the electrode peripheral region D2.

[0034] In the ozone generator having the electrode unit 61 that is the basic configuration of the first embodiment of the present disclosure, the refrigerant flow path 4 provided in the low-voltage electrode 1 that functions as a flow path-integrated metal electrode has the above-mentioned center-priority refrigerant flow path structure, and therefore the temperature of the electrode central region D1 near the gas outlet 12 can be kept relatively low.

[0035] On the other hand, since the raw material gas G1 is supplied from the discharge peripheral space S2 toward the discharge central space S1, the ozone concentration in the discharge central space S1 tends to be higher than the ozone concentration in the discharge peripheral space S2 for the ozone gas G2 generated in the discharge space 6.

[0036] Therefore, in the ozone generator having the basic configuration of the first embodiment, the refrigerant flow path 4 provided in the low-voltage electrode 1 has the above-mentioned central priority refrigerant flow path structure, thereby enhancing the cooling effect in the central discharge space S1, and thereby lowering the temperature in the central discharge space S1, making it possible to minimize the phenomenon of decomposition of ozone gas G2 in a high ozone concentration state.

[0037] As a result, the ozone generator having the basic configuration of the first embodiment can generate a relatively high concentration of ozone gas G2 while minimizing the amount of refrigerant C1.

[0038] In the electrode unit 61 shown in FIG. 2, of the low-voltage electrode 1 and the high-voltage electrode 2, the low-voltage electrode 1 functions as a flow path-integrated metal electrode, but it is sufficient if at least one of the low-voltage electrode 1 and the high-voltage electrode 2 functions as a flow path-integrated metal electrode.

[0039] For example, the high-voltage electrode 2 may be a metal electrode with a built-in flow path, and a refrigerant flow path corresponding to the refrigerant flow path 4 may be provided inside the high-voltage electrode 2. However, the refrigerant flowing through the refrigerant flow path inside the high-voltage electrode 2 must have insulating properties.

[0040] (Ozone Generation Method) An ozone generation method using an ozone generator having the basic configuration of embodiment 1 shown in FIG. 2 (hereinafter, in embodiments 1 and 2, this may be abbreviated as "ozone generation method for basic configuration") includes the following steps (a) to (c).

[0041] Step (a): An AC voltage is applied between a low-voltage electrode 1 serving as a first metal electrode and a high-voltage electrode 2 serving as a second metal electrode to generate a dielectric barrier discharge in a discharge space 6 .

[0042] Step (b): In the refrigerant flow path 4 within the low-voltage electrode 1, a central priority refrigerant flow path setting process is performed by flowing the refrigerant C1 from the refrigerant inlet 4a to the refrigerant outlet 4b, thereby flowing the refrigerant C1 to the electrode central region D1 before the electrode peripheral region D2.

[0043] Step (c): Ozone gas G2 is obtained in the discharge space 6 by supplying raw material gas G1 from the entire periphery of the discharge peripheral space S2 toward the discharge central space S1.

[0044] By performing the above-mentioned steps (a) to (c), the ozone gas G2 obtained in the discharge space 6 is output from the discharge central space S1 to the outside via the gas outlet 12. Note that the order of performing steps (a) to (c) is arbitrary.

[0045] In the ozone generation method for the basic configuration of embodiment 1, the central-priority coolant flow path setting process is performed by the above-mentioned step (b), so it is possible to maintain a relatively low temperature in the electrode central region D1 close to the gas outlet 12. On the other hand, with regard to the ozone gas G2 generated in the discharge space 6, the ozone concentration in the discharge central space S1 tends to be higher than the ozone concentration in the discharge peripheral space S2.

[0046] Therefore, the ozone generation method for the basic configuration can generate a relatively high concentration of ozone gas G2 by performing step (b) to enhance the cooling effect of the discharge central space S1 and minimizing the amount of refrigerant C1.

[0047] (First Aspect) Figure 3 is an explanatory diagram schematically showing the planar structure of the refrigerant flow path 4 of the low-voltage electrode 1A in an ozone generator according to a first aspect of embodiment 1. Figure 4 is an explanatory diagram schematically showing the discharge space 6 above the low-voltage electrode 1A shown in Figure 3. An XYZ Cartesian coordinate system is depicted in each of Figures 3 and 4.

[0048] Figures 5 and 6 are explanatory diagrams schematically showing the cross-sectional structure of the low-voltage electrode 1A shown in Figure 3. Figure 5 shows the A-A cross section of Figure 3, and Figure 6 shows the B-B cross section of Figure 3. An XYZ Cartesian coordinate system is depicted in each of Figures 5 and 6. A first aspect of the first embodiment will be described below with reference to Figures 3 to 6. Note that the first aspect shows the specific structure of the low-voltage electrode 1A, which corresponds to the low-voltage electrode 1 in the electrode unit 61 of the basic configuration shown in Figure 2.

[0049] As shown in Figures 3 and 4, low-voltage electrode 1A has a rectangular shape when viewed in plan in the XY plane. On the other hand, as shown in Figure 4, discharge space 6 has a circular shape when viewed in plan in the XY plane. For example, by forming high-voltage electrode 2 into a circular shape in plan view, discharge space 6 formed between low-voltage electrode 1A and high-voltage electrode 2 can be made circular.

[0050] 3 and 6, the lower surface of the low-voltage electrode 1A has a refrigerant supply port 21 and a refrigerant discharge port 22. The refrigerant supply port 21 receives the refrigerant C1 from the outside, and the refrigerant discharge port 22 discharges the refrigerant C1 to the outside. The refrigerant discharge port 22 also has a cross-sectional structure similar to that of the refrigerant supply port 21 shown in FIG.

[0051] In the low-voltage electrode 1 of the first embodiment, flow path outer wall 25 is provided along the outer periphery, and flow path separation wall 26 is provided inside, so that refrigerant flow path 4 has bent flow paths 41(1) to 41(2) that change the flow path direction, and circulating flow paths 42(1) to 42(3) that each flow refrigerant C1 along the flow path direction. Bent flow paths 41(1) to 41(2) form at least one bent flow path, and circulating flow paths 42(1) to 42(3) form multiple circulating flow paths. Note that flow path outer wall 25 is formed to match the outer periphery of discharge space 6 when viewed in a plan view on the XY plane.

[0052] 3 and 6 , the coolant supply port 21 and the coolant discharge port 22 are arranged at positions that do not overlap with the discharge space 6 in plan view on the XY plane. Furthermore, the coolant supply port 21 and the coolant discharge port 22 are provided on the same +X direction side with respect to the discharge space 6 in plan view.

[0053] The refrigerant flow path 4 is provided with a gas outlet 12 that is blocked from the refrigerant C1 flowing through the refrigerant flow path 4 by a gas outlet wall 16 .

[0054] Among the circular flow paths 42(1) to 42(3), a pair of adjacent circular flow paths 42(i) and 42(i+1) (i = 1 or 2) are connected via a bent flow path 41(i) so that their flow paths are in opposite directions.

[0055] That is, a pair of adjacent circulating flow paths among the plurality of circulating flow paths (circulating flow paths 42(1) to 42(3)) are connected via one of at least one bent flow paths (bent flow paths 41(1) to 41(2)) so that their flow path directions are opposite to each other.

[0056] The circulating flow path 42(1) communicates with the refrigerant supply port 21, and the circulating flow path 42(3) communicates with the refrigerant discharge port 22. Therefore, the circulating flow path 42(1) serves as a supply-side circulating flow path, and the circulating flow path 42(3) serves as a discharge-side circulating flow path.

[0057] That is, the multiple circulating flow paths (circulating flow paths 42(1) to 42(3)) include a supply-side circulating flow path (circulating flow path 42(1)) that communicates with the refrigerant supply port 21, and a discharge-side circulating flow path (circulating flow path 42(3)) that communicates with the refrigerant discharge port 22.

[0058] Of the circular flow paths 42(1) to 42(3), the circular flow path 42(1), which serves as the supply-side circular flow path, is located closest to the gas outlet 12, and the circular flow path 42(3), which serves as the discharge-side circular flow path, is located farthest from the gas outlet 12.

[0059] In this way, refrigerant flow path 4 provided within low-voltage electrode 1A realizes a circular circulation flow path structure in which refrigerant C1 flows through circular flow paths 42(1) to 42(3) and bent flow paths 41(1) to 41(2), such that refrigerant C1 is first supplied from refrigerant supply port 21 to circumferential flow path 42(1), and finally, refrigerant C1 is discharged from circumferential flow path 42(3) to the outside via refrigerant discharge port 22.

[0060] That is, in the first aspect of the first embodiment, a circulating flow path structure is realized as a central-priority refrigerant flow path structure of the basic configuration, and the flow path widths of the circulating flow paths 42(1) to 42(3) and the bent flow paths 41(1) to 41(2) are each set within a certain range.

[0061] The ozone generator according to the first aspect of the first embodiment of the present disclosure achieves the above-described circular circulation flow path structure as a central priority refrigerant flow path structure. Therefore, since the flow path width falls within a certain range, the flow rate of the refrigerant C1 flowing through the refrigerant flow path 4 can be improved and the thermal conductivity of the refrigerant C1 can be maintained relatively high, thereby enhancing the cooling effect of the refrigerant C1 on the discharge space 6.

[0062] In the ozone generator of the first aspect of the first embodiment, the refrigerant supply port 21 and the refrigerant discharge port 22 do not overlap the discharge space 6 in plan view. Therefore, even if the refrigerant supply port 21 and the refrigerant discharge port 22 are provided, the discharge space 6 can be provided without any hindrance between the low-voltage electrode 1A of the electrode configuration unit E1 and the electrode configuration unit E2.

[0063] In the first aspect of embodiment 1, the refrigerant supply port 21 and the refrigerant discharge port 22 are provided in the same direction relative to the discharge space 6 in a plan view, and therefore the refrigerant supply port 21 and the refrigerant discharge port 22 can be arranged close to each other, making it relatively easy to supply the refrigerant C1 from the outside and discharge the refrigerant C1 to the outside.

[0064] In the first aspect of the first embodiment, the discharge space 6 has a circular shape in plan view, so that the source gas G1 can be supplied uniformly from the entire periphery of the discharge space 6 toward the central discharge space.

[0065] (Ozone Generation Method) The ozone generation method using the ozone generator according to the first aspect of the first embodiment shown in FIGS. 3 to 6 includes the following steps (b-1) and (b-2) as the above-described central priority refrigerant flow path setting process in step (b) executed in the ozone generation method for the basic configuration.

[0066] Step (b-1): The refrigerant C1 is supplied from the refrigerant supply port 21 to the circulation flow path 42(1) which serves as the supply-side circulation flow path.

[0067] Step (b-2): The refrigerant C1 is discharged from the circular flow path 42(3) serving as the discharge-side circular flow path to the refrigerant discharge port 22.

[0068] By performing the above-described steps (b-1) and (b-2), a circular circulation flow path is established in refrigerant flow path 4, in which refrigerant C1 flows through circular flow paths 42(1) to 42(3) and bent flow paths 41(1) to 41(2), in such a manner that refrigerant C1 is first supplied from refrigerant supply port 21 to circular flow path 42(1), and finally, refrigerant C1 is discharged from circulatory flow path 42(3) to the outside via refrigerant discharge port 22.

[0069] In the ozone generation method for the first aspect, the above-mentioned circular circulation flow path is set by performing the above-mentioned steps (b-1) and (b-2), so that the flow rate of the refrigerant C1 flowing through the refrigerant flow path 4 can be improved and the thermal conductivity of the refrigerant C1 can be kept relatively high, thereby enhancing the cooling effect of the refrigerant C1 on the discharge space 6.

[0070] (Second Aspect) Fig. 7 is an explanatory diagram schematically showing the planar structure of the refrigerant flow path 4 of the low-voltage electrode 1B in an ozone generator according to a second aspect of embodiment 1. Fig. 7 shows an XYZ orthogonal coordinate system.

[0071] Figures 8 and 9 are explanatory diagrams schematically showing the cross-sectional structure of the low-voltage electrode 1B shown in Figure 7. Figure 8 shows the CC cross section of Figure 7, and Figure 9 shows the DD cross section of Figure 7. An XYZ Cartesian coordinate system is depicted in each of Figures 8 and 9. A second aspect of the first embodiment will be described below with reference to Figures 3 and 7 to 9. The second aspect shows the specific structure of the low-voltage electrode 1B, which corresponds to the low-voltage electrode 1 in the electrode unit 61 of the basic configuration shown in Figure 2.

[0072] The internal structure of the coolant flow path 4 formed in the low voltage electrode 1B is substantially the same as the internal structure of the coolant flow path 4 formed in the low voltage electrode 1A shown in FIG.

[0073] Hereinafter, components similar to those of the first embodiment shown in FIGS. 3 to 6 will be denoted by the same reference numerals and explanations thereof will be omitted as appropriate, and the description will focus on the features of the second embodiment.

[0074] 7 and 8, an ozone gas outlet 19 is provided on the lower surface of low-voltage electrode 1B. Gas outlet 12B communicates with ozone gas passage 15 in an intermediate region without passing through low-voltage electrode 1B. Ozone gas passage 15 is formed horizontally along the X direction, with one end on the −X direction side communicating with the lower end of gas outlet 12B and the other end on the +X direction side communicating with the upper end of ozone gas outlet 19.

[0075] Therefore, the ozone gas G2 obtained in the discharge space 6 passes through the gas outlet 12B and the ozone gas passage 15 and is taken out from the ozone gas outlet 19 to the outside.

[0076] As described above, in the second aspect of the first embodiment, the gas outlet 12B, the ozone gas passage 15, and the ozone gas outlet 19 are provided in correspondence with the gas outlet 12 of the basic configuration shown in FIG.

[0077] The ozone generator according to the second aspect of the first embodiment of the present disclosure has a circular circulation flow path structure, similar to the first aspect. This increases the flow rate of the refrigerant C1 flowing through the refrigerant flow path 4, and maintains a relatively high thermal conductivity of the refrigerant C1, thereby enhancing the cooling effect of the refrigerant C1 on the discharge space 6.

[0078] (Third Aspect) Fig. 10 is an explanatory diagram schematically showing the planar structure of an ozone gas generation unit 55 including a low-voltage electrode 1C in an ozone generator according to a third aspect of embodiment 1. An XYZ orthogonal coordinate system is shown in Fig. 10.

[0079] Figures 11 and 12 are explanatory diagrams schematically showing the cross-sectional structure of the ozone gas generation unit 55 shown in Figure 10. Figure 11 shows the E-E cross section of Figure 10, and Figure 12 shows the F-F cross section of Figure 10. An XYZ Cartesian coordinate system is depicted in each of Figures 11 and 12. Below, a third aspect of the first embodiment will be described with reference to Figures 3 and 10 to 12. Note that the third aspect shows a specific structure of an ozone gas generation unit 55 including a low-voltage electrode 1C that corresponds to the low-voltage electrode 1 in the electrode unit 61 of the basic configuration shown in Figure 2.

[0080] The low-voltage electrode 1C has an ozone gas connection 45, a refrigerant supply connection 46, and a refrigerant discharge connection 47 on the ozone gas / refrigerant auxiliary member 30 side, and the low-voltage electrode 1C is connected to the ozone gas / refrigerant auxiliary member 30 via the ozone gas connection 45, the refrigerant supply connection 46, and the refrigerant discharge connection 47. A plurality of bolt fixing holes 38 are provided in the low-voltage electrode 1C and the ozone gas / refrigerant auxiliary member 30 shown in Figure 10.

[0081] 10, the main portion of the low-voltage electrode 1C is circular when viewed in plan in the XY plane. The main portion of the low-voltage electrode 1C refers to the portion of the low-voltage electrode 1C excluding the ozone gas connection portion 45, the refrigerant supply connection portion 46, and the refrigerant discharge connection portion 47.

[0082] In the third aspect of the first embodiment, for example, the planar shape of the high-voltage electrode 2 is formed to be circular, so that the discharge space 6 has a circular shape when viewed in plan in the XY plane, similar to the first and second aspects.

[0083] The internal structure of the coolant flow path 4 formed in the low-voltage electrode 1C is substantially the same as the internal structure of the coolant flow path 4 formed in the low-voltage electrode 1A shown in FIG.

[0084] Hereinafter, components similar to those of the first embodiment shown in Figures 3 to 6 or the second embodiment shown in Figures 7 to 9 will be assigned the same reference numerals and explanations thereof will be omitted as appropriate, and the description will focus on the characteristic features of the third embodiment.

[0085] As described above, the third embodiment is configured with an ozone gas generating unit 55 including a low-voltage electrode 1C and an auxiliary member 30 for ozone gas and refrigerant.

[0086] As shown in Figures 10 and 12, ozone gas / refrigerant auxiliary member 30 has a refrigerant supply passage 36, which is formed in the Z direction. This refrigerant supply passage 36 also serves as the refrigerant supply port in the third embodiment. As shown in Figure 12, in the refrigerant flow passage 4 formed in low-voltage electrode 1C, circumferential flow passage 42(1) and refrigerant supply passage 36 communicate with each other. In the third embodiment, circumferential flow passage 42(1) is formed to extend through refrigerant supply connection portion 46 of low-voltage electrode 1C and into ozone gas / refrigerant auxiliary member 30.

[0087] Ozone gas / refrigerant auxiliary member 30 further has a refrigerant discharge passage 37, which is also formed along the Z direction like refrigerant supply passage 36. This refrigerant discharge passage 37 also serves as the refrigerant discharge port in the third embodiment. In the refrigerant flow path 4 formed in low-voltage electrode 1C, circumferential flow path 42(3) and refrigerant discharge passage 37 communicate with each other. In the third embodiment, circumferential flow path 42(3) is formed to extend into refrigerant discharge connection portion 47 of low-voltage electrode 1C and ozone gas / refrigerant auxiliary member 30.

[0088] As shown in FIGS. 10 and 11, the ozone gas / refrigerant auxiliary member 30 further includes an ozone gas passage 35, which is also formed along the Z direction, similar to the refrigerant supply passage 36 and the refrigerant discharge passage 37.

[0089] 11 , gas outlet 12C is provided so as to penetrate low-voltage electrode 1C, and its intermediate region is in communication with ozone gas passage 18. Ozone gas passage 18 is formed horizontally along the X direction, with one end on the −X direction side in communication with the intermediate region of gas outlet 12C, and the other end on the +X direction side in communication with ozone gas passage 35.

[0090] In the third embodiment, the ozone gas passage 18 is formed so as to extend into the ozone gas connection portion 45 of the low voltage electrode 1C and the auxiliary member 30 for ozone gas and refrigerant.

[0091] Therefore, the ozone gas G2 obtained in the discharge space 6 flows into the ozone gas passage 35 via the gas outlet 12C and the ozone gas passage 18, and is taken out to the outside from an ozone output port (not shown) that communicates with the ozone gas passage 35 provided in the ozone gas / refrigerant auxiliary member 30.

[0092] 10 , the refrigerant supply passage 36 serving as a refrigerant supply port and the refrigerant discharge passage 37 serving as a refrigerant discharge port are disposed in positions that do not overlap with the discharge space 6 in plan view on the XY plane. Furthermore, the refrigerant supply passage 36 and the refrigerant discharge passage 37 are provided on the same +X direction side with respect to the discharge space 6 in plan view.

[0093] As described above, in the third aspect of the first embodiment, the gas outlet 12C, the ozone gas passage 18, the ozone gas passage 35, and the ozone output port (not shown) are provided in correspondence with the gas outlet 12 of the basic configuration shown in FIG.

[0094] The reason why the gas outlet 12C is provided through the low-voltage electrode 1C is that the ozone gas generating unit 55 is configured with a laminated structure in which an electrode component E2 is also provided on the lower surface side of the low-voltage electrode 1C, and discharge spaces 6 are formed on both the upper and lower surfaces of the low-voltage electrode 1C.

[0095] The ozone generator according to the third aspect of the first embodiment of the present disclosure has a circular circulation flow path structure, similar to the first and second aspects. This increases the flow rate of the refrigerant C1 flowing through the refrigerant flow path 4, and maintains a relatively high thermal conductivity of the refrigerant C1, thereby enhancing the cooling effect of the refrigerant C1 on the discharge space 6.

[0096] Furthermore, in the third aspect of the first embodiment, the ozone gas / refrigerant auxiliary member 30 can perform processes such as supplying and discharging the refrigerant C1 and taking out the ozone gas G2.

[0097] In the ozone generator of the third aspect of the first embodiment, the refrigerant supply passage 36 and the refrigerant discharge passage 37 do not overlap the discharge space 6 in plan view. Therefore, even if the ozone gas / refrigerant auxiliary member 30 having the refrigerant supply passage 36 and the refrigerant discharge passage 37 is provided, the discharge space 6 can be provided without any hindrance between the low-voltage electrode 1C and the electrode configuration part E2.

[0098] Therefore, in the ozone generator of the third aspect of the first embodiment, a stacked structure of a plurality of electrode units 61 each including a low-voltage electrode 1C, a high-voltage electrode 2, and a dielectric 3 can be realized relatively easily.

[0099] In the third aspect of the first embodiment, the refrigerant supply passage 36, which also serves as a refrigerant supply port, and the refrigerant discharge passage 37, which also serves as a refrigerant discharge port, are provided in the same direction relative to the discharge space 6 in a plan view. Therefore, the refrigerant supply passage 36 and the refrigerant discharge passage 37 can be arranged close to each other, making it relatively easy to supply the refrigerant C1 from the outside and discharge the refrigerant C1 to the outside.

[0100] Furthermore, in the third aspect of the first embodiment, the ozone gas / refrigerant auxiliary member 30 having the refrigerant supply passage 36 and the refrigerant discharge passage 37 is used as a dedicated member for supplying and discharging the refrigerant C1, thereby enabling the supply and discharge processes of the refrigerant C1 to be performed with high accuracy.

[0101] (Fourth Aspect) Figure 13 is an explanatory diagram schematically showing the planar structure of refrigerant flow path 4 of low-voltage electrode 1D in an ozone generator according to a fourth aspect of embodiment 1. Figure 14 is an explanatory diagram schematically showing the details of branching and bending region R50(1) of low-voltage electrode 1D shown in Figure 13. An XYZ Cartesian coordinate system is shown in Figures 13 and 14.

[0102] As shown in Fig. 13, the refrigerant flow path 4 of the fourth embodiment has eight branching and bending regions R50(1) to R50(8). Note that the gas outlet provided in the center of the low-voltage electrode 1D is not shown in Fig. 13. Possible gas outlets of the fourth embodiment include structures such as gas outlet 12, gas outlet 12B, and gas outlet 12C of the first to third embodiments.

[0103] A fourth aspect of the first embodiment will be described below with reference to Figures 13 and 14. The fourth aspect shows a specific structure of a low-voltage electrode 1D that corresponds to the low-voltage electrode 1 in the electrode unit 61 having the basic configuration shown in Figure 2.

[0104] 13, similarly to the first embodiment, the lower surface of the low-voltage electrode 1D has a coolant supply port 21 and a coolant discharge port 22. The coolant supply port 21 receives a coolant C1 from the outside, and the coolant discharge port 22 discharges the coolant C1 to the outside.

[0105] In low-voltage electrode 1D of the fourth aspect, flow path outer wall 25 is provided along the outer periphery, and flow path separation wall 27 is provided inside, thereby providing branching and bending regions R50(1) to R50(8). Partial refrigerant flow paths are formed in each of branching and bending regions R50(1) to R50(8). In other words, refrigerant flow path 4 formed in low-voltage electrode 1D includes eight partial refrigerant flow paths corresponding to branching and bending regions R50(1) to R50(8).

[0106] Since the partial refrigerant flow paths formed in each of the branching and bending regions R50(1) to R50(8) have similar structures, the partial refrigerant flow paths formed in the branching and bending region R50(1) shown in Figure 14 will be described below as a representative example.

[0107] 14, the branching and bending region R50(1) includes branching and bending flow paths 51(1) to 51(7) that change the flow path direction, and branching and circulating flow paths 52(1) to 52(8) that allow refrigerant C1 to flow along the flow path direction. Each of the branching and bending flow paths 51(1) to 51(7) corresponds to at least one bent flow path, and each of the branching and circulating flow paths 52(1) to 52(8) corresponds to a plurality of circulating flow paths.

[0108] Among the branch circulation flow paths 52(1) to 52(8), a pair of adjacent branch circulation flow paths 52(i) and 52(i+1) (i = any one of 1 to 7) are connected via a bent flow path 41(i) so that their flow paths are in opposite directions.

[0109] That is, a pair of adjacent circular flow paths among the plurality of circular flow paths (branch circular flow paths 52(1) to 52(8)) are connected via one of at least one bent flow paths (branch refracted flow paths 51(1) to 51(7)) so that the flow paths are in opposite directions.

[0110] Branched circular flow path 52(1) of each of branched bending regions R50(1) to R50(8) communicates with refrigerant supply port 21, and a flow path corresponding to branched circular flow path 52(8) of each of branched bending regions R50(1) to R50(8) communicates with refrigerant discharge port 22. Therefore, branched circular flow path 52(1) serves as a supply-side circular flow path, and a flow path corresponding to branched circular flow path 52(8) serves as a discharge-side circular flow path.

[0111] The flow path equivalent to the branched circular flow path 52(8) means the branched circular flow path 52(K) (K is any of 2 to 8) that is positioned farthest from the gas outlet 12 in each of the branched bending regions R50(1) to R50(8).

[0112] That is, the multiple circular flow paths (branch circular flow paths 52(1) to 52(8)) include a supply-side circular flow path (branch circular flow path 52(1)) that communicates with the refrigerant supply port 21, and a discharge-side circular flow path (a flow path equivalent to branch circular flow path 52(8)) that communicates with the refrigerant discharge port 22.

[0113] Of the branched circular flow paths 52(1) to 52(8), the branched circular flow path 52(1), which serves as the supply-side circular flow path, is located closest to the gas outlet 12, and the flow path equivalent to the branched circular flow path 52(8), which serves as the discharge-side circular flow path, is located farthest from the gas outlet 12.

[0114] As described above, refrigerant flow path 4 provided in low-voltage electrode 1D has a branched supply configuration in which refrigerant C1 is supplied from refrigerant supply port 21 to branched circulating flow paths 52(1) of branching bending regions R50(1) to R50(8). Furthermore, refrigerant flow path 4 has a confluence discharge configuration in which refrigerant C1 merges from flow paths corresponding to branched circulating flow paths 52(8) of branching bending regions R50(1) to R50(8), and is then discharged from the outside via refrigerant discharge port 22. Therefore, refrigerant flow path 4 of the fourth aspect realizes a circulating flow path structure in which refrigerant C1 flows through branched circulating flow paths 52(1) to 52(8) and branching bending flow paths 51(1) to 51(7) in the branched supply configuration and confluence discharge configuration described above.

[0115] That is, in the fourth aspect of the first embodiment, as a basic central-priority refrigerant flow path structure, partial refrigerant flow paths having the branching supply pattern and merging discharge pattern described above are provided in each of the branching bending regions R50(1) to R50(8), and the flow path widths of the partial refrigerant flow paths are set within a certain range.

[0116] In this way, the refrigerant flow path 4 formed in the low-voltage electrode 1D in the fourth aspect of the first embodiment has a plurality of partial refrigerant flow paths corresponding to the branching and bending regions R50(1) to R50(8).

[0117] Each of the plurality of partial refrigerant flow paths has a plurality of branched circular flow paths 52(1) to 52(8) that form a plurality of circular flow paths, and a branched bent flow path 51(1) to 51(7) that forms at least one bent flow path.

[0118] The branched circular flow paths 52(1), which serve as supply-side circular flow paths for each of the plurality of partial refrigerant flow paths, are connected to the refrigerant supply port 21, and the flow paths corresponding to the branched circular flow paths 52(8), which serve as discharge-side circular flow paths for each of the plurality of partial refrigerant flow paths, are connected to the refrigerant discharge port 22.

[0119] As described above, in the fourth aspect of the first embodiment, each of the plurality of partial refrigerant flow paths provided corresponding to the branching and bending regions R50(1) to R50(8) has a circulating flow path structure.

[0120] In the ozone generator according to the fourth aspect of the first embodiment of the present disclosure, a circular circulation flow path structure is realized in each of the branching and bending regions R50(1) to R50(8). This improves the flow rate of the refrigerant C1 flowing through the refrigerant flow path 4, and maintains a relatively high thermal conductivity of the refrigerant C1, thereby enhancing the cooling effect of the refrigerant C1 on the discharge space 6.

[0121] The refrigerant flow path 4 in the ozone generator of the fourth aspect of the first embodiment includes a plurality of partial refrigerant flow paths. A plurality of circulatory flow path structures are realized in such a manner that the refrigerant supply port 21 branches into branch circulatory flow paths 52(1) of the plurality of partial refrigerant flow paths in parallel, and then flow paths corresponding to the branch circulatory flow paths 52(8) of the plurality of partial refrigerant flow paths that are parallel to each other join together and communicate with the refrigerant discharge port 22. In other words, a plurality of circulatory flow path structures are realized corresponding to the plurality of partial refrigerant flow paths.

[0122] In this way, the fourth aspect of the first embodiment can realize a structure with multiple circular circulation channels as a central priority refrigerant channel structure. Meanwhile, the ozone gas G2 generated in the discharge space 6 has a directional component of ozone gas flowing from the entire periphery of the discharge space 6, via the discharge peripheral space S2 and the discharge central space S1, toward the gas outlet 12 in plan view.

[0123] Therefore, the temperature distribution formed by the multiple circular circulation flow path structures is a temperature distribution that precisely opposes the above-mentioned ozone gas direction component, so that the central discharge space S1 can be set to a uniformly low temperature state.

[0124] As a result, the ozone generator according to the fourth aspect of the first embodiment can generate a higher concentration of ozone gas G2 by uniformly increasing the cooling effect in the central discharge space S1 in the discharge space 6.

[0125] (Experimental Results) FIG. 15 shows the relationship between the cooling water flow rate [L / min] of the cooling water, which is the refrigerant flow rate of the refrigerant C1, and the ozone (gas) concentration [g / Nm ３ ] In this figure, the horizontal axis represents the cooling water flow rate and the vertical axis represents the ozone concentration.

[0126] In the figure, ozone gas concentration change line L1 is the ozone gas concentration change line of the ozone generator of embodiment 1 having low-voltage electrode 1 (low-voltage electrodes 1A to 1D), and ozone gas concentration change line L2 is the ozone gas concentration change line of the ozone generator having a conventional low-voltage electrode as represented by Patent Document 1.

[0127] As shown in FIG. 15, the ozone gas concentration change line L1 can generate ozone gas G2 with a relatively high ozone concentration, which is difficult to achieve with the ozone gas concentration change line L2, at a lower cooling water flow rate than the ozone gas concentration change line L2.

[0128] 16 is a graph showing the relationship between the temperature [°C] in the electrode central region D1 of the low-voltage electrode 1 (low-voltage electrodes 1A to 1D) and the ozone (gas) concentration of the ozone gas G2 in accordance with embodiment 1. In the figure, the horizontal axis represents the temperature in the electrode central region D1, and the vertical axis represents the ozone concentration.

[0129] From the ozone gas concentration change line L10 shown in the figure, it can be seen that the lower the temperature of the electrode central region D1, the higher the ozone concentration of the ozone gas G2.

[0130] From the experimental results shown in Figures 15 and 16, it can be understood that the ozone generator of embodiment 1 generates a relatively high concentration of ozone gas G2 by minimizing the amount of refrigerant C1 (cooling water) (cooling water flow rate).

[0131] In the first to fourth aspects of the first embodiment, the coolant supply port 21 (coolant supply passage 36) and the coolant discharge port 22 (coolant discharge passage 37) are configured to be located outside the discharge space 6 in plan view, but other configurations are of course possible. For example, the coolant supply mechanism may be located directly below the coolant inlet 4a of the coolant flow path 4 located on the underside of the low-voltage electrode 1 (1A to 1D). However, the coolant supply mechanism needs to be located in a manner that does not affect the ozone gas G2 output from the gas outlet 12.

[0132] <Second Embodiment> (Basic Configuration) Fig. 17 is an explanatory diagram schematically showing the cross-sectional structure of an electrode unit 62 which is the basic configuration of a second embodiment of the present disclosure. An XYZ Cartesian coordinate system is depicted in the figure. An ozone generator including the electrode unit 62 is the ozone generator of the second embodiment. As shown in the figure, the electrode unit 62 includes electrode components E1 and E22 and a spacer 7 as main components.

[0133] Hereinafter, components similar to those in the basic configuration of the first embodiment shown in FIG. 2 will be denoted by the same reference numerals, and explanations thereof will be omitted as appropriate. The following description will focus on the features of the second embodiment.

[0134] An electrode configuration E22 is provided on the low-voltage electrode 1 of the electrode configuration E1 via a spacer 7. The electrode configuration E22 includes, as its main components, a high-voltage electrode 2, a dielectric 3, an insulating structure 5, and a cooling plate 8. The dielectric 3 is formed on the lower surface of the high-voltage electrode 2.

[0135] The low voltage electrode 1 functions as a metal electrode having a refrigerant flow path 4, similar to the first embodiment.

[0136] In the electrode configuration portion E22, an insulating structure 5 is provided on the upper surface of the high-voltage electrode 2. That is, the insulating structure 5 is provided on the opposite side of the discharge space 6 adjacent to the high-voltage electrode 2 which serves as the second metal electrode.

[0137] Furthermore, a cooling plate 8 having a cooling function is provided on the upper surface of the insulating structure 5. That is, the cooling plate 8 is provided adjacent to the insulating structure 5 on the opposite side of the discharge space 6.

[0138] The cooling plate 8 has a refrigerant flow path 9 therein, which serves as a second refrigerant flow path for flowing a refrigerant C2 serving as a second refrigerant. The cooling plate 8 also has a central cooling region B1 that overlaps with the central discharge space S1 in plan view in the XY plane, and a peripheral cooling region B2 that overlaps with the peripheral discharge space S2 in plan view in the XY plane.

[0139] The refrigerant flow path 9 provided in the cooling plate 8 has a refrigerant inlet 9a in a central region on the top surface of the cooling plate 8 and a refrigerant outlet 9b on a side surface of the cooling plate 8, and is formed from the central cooling region B1 to the peripheral cooling region B2. The refrigerant flow path 9 has a second central priority refrigerant flow path structure in which the refrigerant C2 flows from the refrigerant inlet 9a toward the refrigerant outlet 9b, causing the refrigerant C2 to flow to the central cooling region B1 before the peripheral cooling region B2.

[0140] The ozone generator of embodiment 2 having electrode unit 62 is provided with cooling plate 8, so that discharge space 6 can be cooled from the low-voltage electrode 1 side by low-voltage electrode 1 having refrigerant flow path 4 through which refrigerant C1 flows, and discharge space 6 can also be cooled from the high-voltage electrode 2 side by cooling plate 8.

[0141] As a result, the ozone generator of the second embodiment can further enhance the cooling effect of the discharge space 6.

[0142] Furthermore, since the cooling plate 8 in the ozone generator of embodiment 2 has the second central priority refrigerant flow path structure described above, the temperature of the cooling central region B1, which is located from the high-voltage electrode 2 side and close to the gas outlet port 12, can be kept relatively low.

[0143] As a result, the ozone generator of the second embodiment can generate a higher concentration of ozone gas G2 by minimizing the amount of the second refrigerant C2, which is the second refrigerant.

[0144] In the second embodiment, the basic configuration shown in FIG. 17 can also be expanded to realize a structure similar to the first to fourth aspects of the first embodiment, and similar effects can be achieved.

[0145] <Third Embodiment> (Basic Configuration) Fig. 18 is an explanatory diagram schematically showing the cross-sectional structure of an electrode unit 63 which is the basic configuration of a third embodiment of the present disclosure. An XYZ Cartesian coordinate system is depicted in the figure. An ozone generator including the electrode unit 63 is the ozone generator of the third embodiment. As shown in the figure, the electrode unit 63 includes electrode components E1R and E2 and a spacer 7 as main components.

[0146] Hereinafter, components similar to those in the basic configuration of the first embodiment shown in FIG. 2 will be denoted by the same reference numerals, and explanations thereof will be omitted as appropriate. The following description will focus on the features of the third embodiment.

[0147] The electrode configuration E1R includes a low-voltage electrode 1R as a main component. The low-voltage electrode 1R, which is a flat first metal electrode, has a gas supply port 11 that penetrates the center as a gas supply port provided in the center.

[0148] An electrode configuration E2 is provided on the low-voltage electrode 1R of the electrode configuration E1R via a spacer 7. The electrode configuration E2 includes, as its main components, a high-voltage electrode 2 and a dielectric 3. The dielectric 3, which is an electrode dielectric, is formed on the lower surface of the high-voltage electrode 2, which is a flat-plate-shaped second metal electrode.

[0149] In the third embodiment, dielectric 3 serving as the electrode dielectric is provided adjacent to high-voltage electrode 2, but it may also be provided adjacent to low-voltage electrode 1R. That is, it is sufficient to provide at least one electrode dielectric between low-voltage electrode 1R and high-voltage electrode 2, adjacent to at least one of low-voltage electrode 1R and high-voltage electrode 2.

[0150] However, it is necessary that the discharge space 6 be provided in contact with at least one electrode dielectric between the low-voltage electrode 1R and the high-voltage electrode 2. In other words, when forming an electrode dielectric in the electrode configuration portion E1R, it is necessary to provide the electrode dielectric on the upper surface of the low-voltage electrode 1R.

[0151] In the electrode unit 63 shown in FIG. 18, as in the electrode unit 61 of the first embodiment, a dielectric barrier discharge can be generated in the discharge space 6 by applying an AC voltage between the low voltage electrode 1R and the high voltage electrode 2.

[0152] The discharge space 6 includes a central discharge space S1 communicating with the gas supply port 11 and a peripheral discharge space S2 existing around the central discharge space S1. The external space communicating with the peripheral discharge space S2 serves as the ozone gas output space. In other words, the space communicating with the peripheral discharge space S2 around the entire periphery of the discharge space 6 serves as the ozone gas output space.

[0153] 18, source gas G1 is supplied from below gas supply port 11 of low-voltage electrode 1R, and is supplied from the center of discharge space 6 toward the entire periphery. That is, source gas G1 is supplied from discharge central space S1 toward discharge peripheral space S2. Ozone gas G2 is obtained by passing source gas G1 through discharge space 6 where a dielectric barrier discharge is generated.

[0154] The ozone gas G2 obtained in the discharge space 6 is output to an external ozone gas output space via the discharge peripheral space S2.

[0155] The low-voltage electrode 1R functions as a flow path-integrated metal electrode and has a refrigerant flow path 4R therein through which a refrigerant C1 flows. The low-voltage electrode 1R, which functions as a flow path-integrated metal electrode, has an electrode central region D1 that overlaps with the discharge central space S1 in plan view in the XY plane, and an electrode peripheral region D2 that overlaps with the discharge peripheral space S2 in plan view in the XY plane.

[0156] The refrigerant flow path 4R provided in the low-voltage electrode 1R has a refrigerant inlet 4Ra on the side of the low-voltage electrode 1, a refrigerant outlet 4Rb in a central region on the underside of the low-voltage electrode 1, and is formed from the electrode peripheral region D2 to the electrode central region D1. The refrigerant flow path 4R provided in the low-voltage electrode 1R has a periphery-priority refrigerant flow path structure in which the refrigerant C1 flows from the refrigerant inlet 4Ra to the refrigerant outlet 4Rb, causing the refrigerant C1 to flow to the electrode peripheral region D2 before the electrode central region D1.

[0157] In an ozone generator having an electrode unit 63 that is the basic configuration of the third embodiment of the present disclosure, the refrigerant flow path 4R provided in the low-voltage electrode 1R that functions as a flow path-integrated metal electrode has the above-mentioned periphery-priority refrigerant flow path structure, and therefore, the temperature of the electrode peripheral region D2 close to the ozone gas output space can be kept relatively low.

[0158] On the other hand, since the raw material gas G1 is supplied from the discharge central space S1 toward the discharge peripheral space S2, the ozone concentration in the discharge peripheral space S2 tends to be higher than the ozone concentration in the discharge central space S1 for the ozone gas G2 generated in the discharge space 6.

[0159] Therefore, in the ozone generator having the basic configuration of the third embodiment, the refrigerant flow path 4R provided in the low-voltage electrode 1R has the above-mentioned periphery-priority refrigerant flow path structure, thereby enhancing the cooling effect in the discharge peripheral space S2, thereby lowering the temperature in the discharge peripheral space S2 and minimizing the phenomenon of decomposition of ozone gas G2 in a high ozone concentration state.

[0160] As a result, the ozone generator having the basic configuration of the third embodiment can generate a relatively high concentration of ozone gas G2 while minimizing the amount of refrigerant C1.

[0161] In the electrode unit 63 shown in Figure 18, of the low-voltage electrode 1R and the high-voltage electrode 2, the low-voltage electrode 1R functions as a flow path-integrated metal electrode, but it is sufficient if at least one of the low-voltage electrode 1R and the high-voltage electrode 2 functions as a flow path-integrated metal electrode.

[0162] For example, the high-voltage electrode 2 may be a metal electrode with a built-in flow path, and a refrigerant flow path corresponding to the refrigerant flow path 4R may be provided within the high-voltage electrode 2. However, the refrigerant flowing through the refrigerant flow path within the high-voltage electrode 2 must have insulating properties.

[0163] (Ozone Generation Method) An ozone generation method using an ozone generator having the basic configuration of embodiment 3 shown in FIG. 18 (hereinafter, in embodiments 3 and 4, this may be abbreviated as "ozone generation method for basic configuration") includes the following steps (a) to (c).

[0164] Step (a): An AC voltage is applied between the low voltage electrode 1R, which serves as the first metal electrode, and the high voltage electrode 2, which serves as the second metal electrode, to generate a dielectric barrier discharge in the discharge space 6.

[0165] Step (b): In the refrigerant flow path 4R within the low-voltage electrode 1R, a peripheral priority refrigerant flow path setting process is performed in which the refrigerant C1 flows from the refrigerant inlet 4Ra to the refrigerant outlet 4Rb, causing the refrigerant C1 to flow to the electrode peripheral region D2 before the electrode central region D1.

[0166] Step (c): Ozone gas G2 is obtained in the discharge space 6 by supplying raw material gas G1 from gas supply port 11 toward discharge peripheral space S2 via discharge central space S1.

[0167] By carrying out the above steps (a) to (c), the ozone gas G2 obtained in the discharge space 6 is output to the external ozone gas output space from the entire periphery of the discharge peripheral space S2 via the discharge peripheral space S2.

[0168] In the ozone generation method for the basic configuration, the temperature of the discharge peripheral space S2 can be kept relatively low because the peripheral-priority coolant flow path setting process is performed by the above-mentioned step (b). On the other hand, with regard to the ozone gas G2 generated in the discharge space 6, the ozone concentration in the discharge peripheral space S2 tends to be higher than the ozone concentration in the discharge central space S1.

[0169] Therefore, the ozone generation method for the basic configuration can generate a relatively high concentration of ozone gas G2 by performing step (b) to enhance the cooling effect of the discharge peripheral space S2 and minimizing the amount of refrigerant C1.

[0170] (First aspect) Figure 19 is an explanatory diagram schematically showing the planar structure of a refrigerant flow path 4R of a low-voltage electrode 1AR in an ozone generator according to a first aspect of embodiment 3. Figure 20 is an explanatory diagram schematically showing a discharge space 6 above the low-voltage electrode 1AR shown in Figure 19. An XYZ Cartesian coordinate system is depicted in each of Figures 19 and 20.

[0171] Figures 21 and 22 are explanatory diagrams schematically showing the cross-sectional structure of the low-voltage electrode 1AR shown in Figure 19. Figure 21 shows the G-G cross section of Figure 19, and Figure 22 shows the H-H cross section of Figure 19. An XYZ Cartesian coordinate system is depicted in each of Figures 21 and 22. Below, a first aspect of embodiment 3 will be described with reference to Figures 19 to 22. Note that the first aspect shows the specific structure of the low-voltage electrode 1AR corresponding to the low-voltage electrode 1R in the electrode unit 63 of the basic configuration shown in Figure 18.

[0172] 19 and 20, the low-voltage electrode 1AR has a rectangular shape when viewed in plan in the XY plane. On the other hand, as shown in Fig. 20, the discharge space 6 has a circular shape when viewed in plan in the XY plane. For example, by forming the high-voltage electrode 2 into a circular shape in plan view, the discharge space 6 formed between the low-voltage electrode 1AR and the high-voltage electrode 2 can be made circular.

[0173] 19 and 22, the lower surface of low-voltage electrode 1AR has coolant supply port 21R and coolant discharge port 22R. Coolant discharge port 22R discharges coolant C1 from circumferential flow path 42(1), and coolant supply port 21R supplies coolant C1 to circumferential flow path 42(3) within low-voltage electrode 1AR. Coolant supply port 21R has a cross-sectional structure similar to that of coolant discharge port 22R shown in FIG.

[0174] In low-voltage electrode 1AR of the first aspect, flow path outer wall 25 is provided along the outer periphery, and flow path separation wall 26 is provided inside, so that refrigerant flow path 4R has bent flow paths 41(1) to 41(2) that change the flow path direction, and circulating flow paths 42(1) to 42(3) that each flow refrigerant C1 along the flow path direction. That is, in the first aspect of Embodiment 3, similar to the first aspect of Embodiment 1, bent flow paths 41(1) to 41(2) form at least one bent flow path, and circulating flow paths 42(1) to 42(3) form multiple circulating flow paths.

[0175] 19 and 22 , the coolant supply port 21R and the coolant discharge port 22R are arranged at positions that do not overlap with the discharge space 6 in plan view on the XY plane. Furthermore, the coolant supply port 21R and the coolant discharge port 22R are provided on the same +X direction side with respect to the discharge space 6 in plan view.

[0176] The coolant flow path 4R is provided with a gas supply port 11 that is blocked from the coolant C1 flowing through the coolant flow path 4R by a gas outlet wall 16.

[0177] Among the circular flow paths 42(1) to 42(3), a pair of adjacent circular flow paths 42(i+1) and 42(i) (i = 2 or 1) are connected via a bent flow path 41(i) so that their flow paths are in opposite directions.

[0178] That is, a pair of adjacent circulating flow paths among the plurality of circulating flow paths (circulating flow paths 42(1) to 42(3)) are connected via one of at least one bent flow paths (bent flow paths 41(1) to 41(2)) so that their flow path directions are opposite to each other.

[0179] The circulating flow path 42(1) communicates with the refrigerant discharge port 22R, and the circulating flow path 42(3) communicates with the refrigerant supply port 21R. Therefore, the circulating flow path 42(1) serves as a discharge-side circulating flow path, and the circulating flow path 42(3) serves as a supply-side circulating flow path.

[0180] That is, the multiple circulating flow paths (circulating flow paths 42(1) to 42(3)) include a supply-side circulating flow path (circulating flow path 42(3)) that communicates with the refrigerant supply port 21R, and a discharge-side circulating flow path (circulating flow path 42(1)) that communicates with the refrigerant discharge port 22R.

[0181] Of the circular flow paths 42(1) to 42(3), the circular flow path 42(3), which serves as the supply-side circular flow path, is located farthest from the gas supply port 11, and the circular flow path 42(1), which serves as the discharge-side circular flow path, is located closest to the gas supply port 11.

[0182] In this way, refrigerant flow path 4R provided within low-voltage electrode 1AR realizes a circular circulation flow path structure in which refrigerant C1 flows through circular flow paths 42(1)-42(3) and bent flow paths 41(1)-41(2) so that refrigerant C1 is first supplied from refrigerant supply port 21R to circumferential flow path 42(3), and finally, refrigerant C1 is discharged from circumferential flow path 42(1) to the outside via refrigerant discharge port 22R.

[0183] That is, in the first aspect of the third embodiment, a circulating flow path structure is realized as a peripheral-priority refrigerant flow path structure of the basic configuration, and the flow path widths of the circulating flow paths 42(1) to 42(3) and the bent flow paths 41(1) to 41(2) are each set within a certain range.

[0184] The ozone generator according to the first aspect of the third embodiment of the present disclosure achieves the above-described circular circulation flow path structure as a periphery-priority refrigerant flow path structure. Therefore, the flow path width falls within a certain range, which improves the flow rate of the refrigerant C1 flowing through the refrigerant flow path 4R and maintains relatively high thermal conductivity of the refrigerant C1, thereby enhancing the cooling effect of the refrigerant C1 on the discharge space 6.

[0185] In the ozone generator of the first aspect of the third embodiment, the refrigerant supply port 21R and the refrigerant discharge port 22R do not overlap the discharge space 6 in plan view. Therefore, even if the refrigerant supply port 21R and the refrigerant discharge port 22R are provided, the discharge space 6 can be provided between the low-voltage electrode 1AR and the electrode configuration part E2 without any hindrance.

[0186] In the first aspect of embodiment 3, the refrigerant supply port 21R and the refrigerant discharge port 22R are arranged in the same direction relative to the discharge space 6 when viewed in a plane. Therefore, the refrigerant supply port 21R and the refrigerant discharge port 22R can be arranged close to each other, making it relatively easy to supply the refrigerant C1 from the outside and discharge the refrigerant C1 to the outside.

[0187] In the first aspect of the third embodiment, the discharge space 6 has a circular shape in a plan view, so that the ozone gas G2 can be output evenly from the entire periphery of the discharge space 6 to the external ozone gas output space.

[0188] (Ozone Generation Method) The ozone generation method using the ozone generator according to the first aspect of the third embodiment shown in FIGS. 19 to 22 includes the following steps (b-1) and (b-2) as the peripheral-priority refrigerant flow path setting process described above in step (b) executed in the ozone generation method for the basic configuration.

[0189] Step (b-1): The refrigerant C1 is supplied from the refrigerant supply port 21R to the circulation flow path 42(3) which serves as the supply-side circulation flow path.

[0190] Step (b-2): The refrigerant C1 is discharged from the circular flow path 42(1) serving as the discharge-side circular flow path to the refrigerant discharge port 22R.

[0191] By performing the above-described steps (b-1) and (b-2), a circular circulation flow path is established in refrigerant flow path 4R, in which refrigerant C1 flows through circular flow paths 42(1)-42(3) and bent flow paths 41(1)-41(2), in such a manner that refrigerant C1 is first supplied from refrigerant supply port 21R to circular flow path 42(3), and finally, refrigerant C1 is discharged from circulatory flow path 42(1) to the outside via refrigerant discharge port 22R.

[0192] In the ozone generation method for the first aspect, the above-mentioned circular circulation flow path is set by performing the above-mentioned steps (b-1) and (b-2), so that the flow rate of the refrigerant C1 flowing through the refrigerant flow path 4R can be improved and the thermal conductivity of the refrigerant C1 can be kept relatively high, thereby enhancing the cooling effect of the refrigerant C1 on the discharge space 6.

[0193] (Second Aspect) In the third embodiment, a structure similar to that of the second embodiment of the first embodiment shown in Figures 7 to 9 can be realized. The same effects as those of the second embodiment of the first embodiment can be achieved. In this case, the gas supply port, source gas inlet, coolant discharge port 22R, and coolant supply port 21R in the second embodiment of the third embodiment correspond to the gas outlet 12B, ozone gas outlet 19, coolant supply port 21, and coolant discharge port 22 in the second embodiment of the first embodiment.

[0194] 10 to 12, a structure similar to that of the third aspect of the first embodiment can be realized in the third embodiment. The same effects as those of the third aspect of the first embodiment can be achieved. In this case, the gas supply port, the source gas passage, the coolant discharge port, and the coolant supply port in the third aspect of the third embodiment correspond to the gas outlet 12C, the ozone gas passage 35, the coolant supply passage 36, and the coolant discharge passage 37 in the third aspect of the first embodiment.

[0195] (Fourth Aspect) Figure 23 is an explanatory diagram schematically showing the planar structure of a refrigerant flow path 4R of a low-voltage electrode 1DR in an ozone generator according to a fourth aspect of embodiment 3. Figure 24 is an explanatory diagram schematically showing the details of a branching bending region R50(1) of the low-voltage electrode 1DR shown in Figure 23. An XYZ Cartesian coordinate system is shown in Figures 23 and 24.

[0196] As shown in Fig. 23, the coolant flow path 4R of the fourth embodiment has eight branching and bending regions R50(1) to R50(8). Note that the gas supply port provided in the center of the low-voltage electrode 1DR is not shown in Fig. 23. The gas supply port of the fourth embodiment may have the same structure as gas supply port 11 of the first embodiment.

[0197] A fourth aspect of the third embodiment will be described below with reference to Figures 23 and 24. The fourth aspect shows a specific structure of a low-voltage electrode 1DR that corresponds to the low-voltage electrode 1R in the electrode unit 63 having the basic configuration shown in Figure 18.

[0198] 23, similarly to the first embodiment, the low-voltage electrode 1DR has a coolant supply port 21R and a coolant discharge port 22R on the lower surface thereof. The coolant supply port 21R receives the coolant C1 from the outside, and the coolant discharge port 22R discharges the coolant C1 to the outside.

[0199] In low-voltage electrode 1DR of the fourth aspect, branching and bending regions R50(1) to R50(8) are formed by providing flow path outer wall 25 along the outer periphery and flow path separation wall 27 inside. Partial refrigerant flow paths are formed in each of branching and bending regions R50(1) to R50(8). In other words, refrigerant flow path 4R formed in low-voltage electrode 1DR includes eight partial refrigerant flow paths corresponding to branching and bending regions R50(1) to R50(8).

[0200] Since the partial refrigerant flow paths formed in the branching and bending regions R50(1) to R50(8) have similar structures, the partial refrigerant flow path formed in the branching and bending region R50(1) shown in Figure 24 will be described below as a representative example.

[0201] In the branching and bending region R50(1), branching and bending flow paths 51(1) to 51(7) that change the flow path direction and branching and circulating flow paths 52(1) to 52(8) that each allow refrigerant C1 to flow along the flow path direction are provided. That is, in the fourth aspect of the third embodiment, similar to the fourth aspect of the first embodiment, branching and bending flow paths 51(1) to 51(7) correspond to at least one bent flow path, and branching and circulating flow paths 52(1) to 52(8) correspond to multiple circulating flow paths.

[0202] Among branch circulation flow paths 52(1) to 52(8), a pair of adjacent branch circulation flow paths 52(i+1) and branch circulation flow path 52(i) (i = any one of 7 to 1) are connected via bent flow path 41(i) so that their flow paths are in opposite directions.

[0203] That is, a pair of adjacent circular flow paths among the plurality of circular flow paths (branch circular flow paths 52(1) to 52(8)) are connected via one of at least one bent flow paths (branch refracted flow paths 51(1) to 51(7)) so that the flow paths are in opposite directions.

[0204] The flow paths corresponding to branched circulation flow paths 52(8) of each of branching and bending regions R50(1) to R50(8) communicate with refrigerant supply port 21R, and branched circulation flow paths 52(1) of each of branching and bending regions R50(1) to R50(8) communicate with refrigerant discharge port 22R. Therefore, the flow paths corresponding to branched circulation flow paths 52(8) serve as supply-side circulation flow paths, and branched circulation flow paths 52(1) serve as discharge-side circulation flow paths.

[0205] That is, the multiple circular flow paths (branch circular flow paths 52(1) to 52(8)) include a supply-side circular flow path (a flow path equivalent to branch circular flow path 52(8)) that communicates with refrigerant supply port 21R, and a discharge-side circular flow path (branch circular flow path 52(1)) that communicates with refrigerant discharge port 22R.

[0206] Of the branched circular flow paths 52(1) to 52(8), the flow path corresponding to the branched circular flow path 52(8), which serves as the supply-side circular flow path, is located farthest from the gas supply port 11, and the branched circular flow path 52(1), which serves as the discharge-side circular flow path, is located closest to the gas supply port 11.

[0207] As described above, refrigerant flow path 4R provided within low-voltage electrode 1DR has a branched supply configuration in which refrigerant C1 is supplied from refrigerant supply port 21R to flow paths corresponding to branched circulating flow paths 52(8) in branching bending regions R50(1) to R50(8). Furthermore, refrigerant flow path 4R has a confluence discharge configuration in which refrigerant C1 merges from branched circulating flow paths 52(1) in branching bending regions R50(1) to R50(8) and is discharged to the outside via refrigerant discharge port 22R. Therefore, refrigerant flow path 4R of the fourth aspect realizes a circulating flow path structure in which refrigerant C1 flows through branched circulating flow paths 52(1) to 52(8) and branched bending flow paths 51(1) to 51(7) in the branched supply configuration and confluence discharge configuration described above.

[0208] That is, in the fourth aspect of the third embodiment, as a peripheral-priority refrigerant flow path structure of the basic configuration, partial refrigerant flow paths having the branching supply pattern and merging discharge pattern described above are provided in each of the branching bending regions R50(1) to R50(8), and the flow path width of the partial refrigerant flow paths is set within a certain range.

[0209] In this way, the refrigerant flow path 4R formed in the low-voltage electrode 1DR in the fourth aspect of the third embodiment has a plurality of partial refrigerant flow paths corresponding to the branching and bending regions R50(1) to R50(8).

[0210] Each of the plurality of partial refrigerant flow paths has a plurality of branched circular flow paths 52(1) to 52(8) that form a plurality of circular flow paths, and a branched bent flow path 51(1) to 51(7) that forms at least one bent flow path.

[0211] The flow paths corresponding to the branched circular flow paths 52(8), which serve as supply-side circular flow paths for each of the plurality of partial refrigerant flow paths, are connected to the refrigerant supply port 21R, and the branched circular flow paths 52(1), which serve as discharge-side circular flow paths for each of the plurality of partial refrigerant flow paths, are connected to the refrigerant discharge port 22R.

[0212] As described above, in the fourth aspect of the third embodiment, each of the plurality of partial refrigerant flow paths provided corresponding to the branching and bending regions R50(1) to R50(8) has a circulating flow path structure.

[0213] In the ozone generator according to the fourth aspect of the third embodiment of the present disclosure, a circular circulation flow path structure is realized in each of the branching and bending regions R50(1) to R50(8). This improves the flow rate of the refrigerant C1 flowing through the refrigerant flow path 4R, and maintains a relatively high thermal conductivity of the refrigerant C1, thereby enhancing the cooling effect of the refrigerant C1 on the discharge space 6.

[0214] The refrigerant flow path in the ozone generator of the fourth aspect of the third embodiment includes a plurality of partial refrigerant flow paths. Therefore, a plurality of circulating flow path structures are realized in such a manner that the refrigerant supply port 21R branches into parallel paths corresponding to the branch circulating flow paths 52(8) of each of the partial refrigerant flow paths, and then the branch circulating flow paths 52(1) of each of the parallel partial refrigerant flow paths join together and communicate with the refrigerant discharge port 22R. In other words, a plurality of circulating flow path structures are realized corresponding to the plurality of partial refrigerant flow paths.

[0215] In this way, the fourth aspect of the third embodiment can realize a structure with multiple circular circulation channels as a periphery-prioritized refrigerant channel structure. On the other hand, the ozone gas G2 generated in the discharge space 6 has an ozone gas directional component that flows from the gas supply port 11 toward the entire periphery of the discharge space 6 via the discharge central space S1 and the discharge peripheral space S2.

[0216] Therefore, the temperature distribution formed by the multiple circular circulation flow path structures is a temperature distribution that precisely opposes the above-mentioned ozone gas direction component, so that the discharge peripheral space S2 can be set to a uniformly low temperature state.

[0217] As a result, the ozone generator according to the fourth aspect of the third embodiment can generate a higher concentration of ozone gas G2 by uniformly increasing the cooling effect of the discharge peripheral space S2 in the discharge space 6.

[0218] In the first to fourth aspects of the third embodiment, the coolant supply port 21R and the coolant discharge port 22R are provided outside the discharge space 6 in plan view, but other configurations are of course possible. For example, the coolant discharge mechanism may be provided directly below the coolant outlet 4Rb of the coolant flow path 4R provided on the underside of the low-voltage electrode 1R (1AR, 1DR). However, the coolant discharge mechanism needs to be provided in a manner that does not affect the source gas G1 supplied from the gas supply port 11.

[0219] <Fourth Embodiment> (Basic Configuration) Fig. 25 is an explanatory diagram schematically showing the cross-sectional structure of an electrode unit 64 which is the basic configuration of a fourth embodiment of the present disclosure. An XYZ Cartesian coordinate system is depicted in the figure. An ozone generator including the electrode unit 64 is the ozone generator of the fourth embodiment. As shown in the figure, the electrode unit 64 includes electrode components E1R and E22R and a spacer 7 as main components.

[0220] Hereinafter, components similar to those in the basic configuration of the third embodiment shown in FIG. 18 will be denoted by the same reference numerals and explanations thereof will be omitted as appropriate, and the description will focus on the features of the fourth embodiment.

[0221] An electrode configuration E22R is provided on the low-voltage electrode 1R of the electrode configuration E1R via a spacer 7. The electrode configuration E22R includes a high-voltage electrode 2, a dielectric 3, an insulating structure 5, and a cooling plate 8R as main components. The dielectric 3 is formed on the lower surface of the high-voltage electrode 2.

[0222] The low voltage electrode 1R functions as a metal electrode having a refrigerant flow path 4, similar to the third embodiment.

[0223] In the electrode configuration portion E22R, an insulating structure 5 is provided on the upper surface of the high-voltage electrode 2. That is, the insulating structure 5 is provided on the opposite side of the discharge space 6 adjacent to the high-voltage electrode 2 which serves as the second metal electrode.

[0224] Furthermore, a cooling plate 8R having a cooling function is provided on the upper surface of the insulating structure 5. That is, the cooling plate 8R is provided adjacent to the insulating structure 5 on the opposite side of the discharge space 6.

[0225] The cooling plate 8R has a refrigerant flow path 9R therein, which serves as a second refrigerant flow path for flowing a refrigerant C2 serving as a second refrigerant. The cooling plate 8R also has a cooling central region B1 that overlaps with the discharge central space S1 in plan view in the XY plane, and a cooling peripheral region B2 that overlaps with the discharge peripheral space S2 in plan view in the XY plane.

[0226] The refrigerant flow path 9R provided in the cooling plate 8R has a refrigerant inlet 9Ra on the side of the cooling plate 8R, a refrigerant outlet 9Rb in the central region on the top surface of the cooling plate 8R, and is formed from the cooling peripheral region B2 to the cooling central region B1. The refrigerant flow path 9R has a second peripheral-priority refrigerant flow path structure in which the refrigerant C2 flows from the refrigerant inlet 9Ra toward the refrigerant outlet 9Rb, causing the refrigerant C2 to flow to the cooling peripheral region B2 before the cooling central region B1.

[0227] The ozone generator of embodiment 4 having electrode unit 64 is provided with cooling plate 8R, so that discharge space 6 can be cooled from the low-voltage electrode 1R side by low-voltage electrode 1R having refrigerant flow path 4R through which refrigerant C1 flows, and discharge space 6 can also be cooled from the high-voltage electrode 2 side by cooling plate 8R.

[0228] As a result, the ozone generator of the fourth embodiment can further enhance the cooling effect of the discharge space 6.

[0229] Furthermore, since the cooling plate 8R in the ozone generator of embodiment 4 has the second periphery-priority refrigerant flow path structure described above, the temperature of the cooling peripheral region B2, which is close to the ozone gas output space around the entire periphery of the discharge space 6 from the high-voltage electrode 2 side, can be kept relatively low.

[0230] As a result, the ozone generator of the fourth embodiment can generate a higher concentration of ozone gas G2 by minimizing the amount of the second refrigerant C2, which is the second refrigerant.

[0231] In addition, in the fourth embodiment, the basic configuration shown in FIG. 25 can be expanded to realize a structure similar to the first to fourth aspects of the third embodiment, and similar effects can be achieved.

[0232] Although the present disclosure has been described in detail, the above description is illustrative in all respects and does not limit the present disclosure to the above. It is understood that countless variations not illustrated can be envisioned without departing from the scope of the present disclosure.

[0233] In the above-described embodiment, the gas outlet 12 (12B, 12C) is provided in the center of the low-voltage electrode 1 (1A to 1D, 1AR, 1DR), but it is sufficient if at least one of the low-voltage electrode 1 and the high-voltage electrode 2 has the gas outlet 12 in the center.

[0234] REFRIGERATED POINTS OF SYMBOL 1, 1A to 1D, 1AR, 1DR Low voltage electrode 2 High voltage electrode 3 Dielectric 4, 4R, 9, 9R Coolant flow path 5 Insulating structure 6 Discharge space 8, 8R Cooling plate 11 Gas supply port 12, 12B, 12C Gas outlet 19 Ozone gas outlet 21 Coolant supply port 22 Coolant discharge port 30 Auxiliary member for ozone gas and coolant 35 Ozone gas passage 36 Coolant supply passage 37 Coolant discharge passage 55 Ozone gas generating unit 61 to 64 Electrode unit C1, C2 Coolant E1, E1R, E2, E22, E22R Electrode configuration part G1 Raw material gas G2 Ozone gas

Claims

1. A plasma generating device comprising: a first flat metal electrode; and a second flat metal electrode disposed opposite the first metal electrode, at least one of the first and second metal electrodes having a gas outlet at its center; further comprising at least one electrode dielectric disposed adjacent to at least one of the first and second metal electrodes between the first and second metal electrodes; a discharge space is provided between the first and second metal electrodes in contact with the at least one electrode dielectric; a voltage is applied between the first and second metal electrodes to generate a dielectric barrier discharge in the discharge space; a source gas is supplied to the discharge space, and ozone gas is obtained by the source gas passing through the discharge space where the dielectric barrier discharge is generated; the discharge space includes a discharge central space communicating with the gas outlet and a discharge peripheral space present around the discharge central space, and the source gas is supplied from the discharge peripheral space toward the discharge central space; at least one of the first and second metal electrodes is a flow path-integrated metal electrode; an electrode peripheral region overlapping with the discharge central space in a plan view, and an electrode peripheral region overlapping with the discharge peripheral space in a plan view; the metal electrode has a refrigerant flow path therein for flowing a refrigerant, the refrigerant flow path being formed from the electrode central region to the electrode peripheral region; the ozone gas obtained in the discharge space is output from the discharge central space to the outside via the gas outlet; and the refrigerant flow path has a center-priority refrigerant flow path structure that causes the refrigerant to flow to the electrode central region before the electrode peripheral region.

2. An ozone generator according to claim 1, further comprising a refrigerant supply port that receives the refrigerant from the outside, and a refrigerant discharge port that discharges the refrigerant to the outside, wherein the refrigerant flow path includes at least one bent flow path that changes a flow direction, and a plurality of circulating flow paths that each flow the refrigerant along the flow direction, wherein a pair of adjacent circulating flow paths among the plurality of circulating flow paths are connected via one of the at least one bent flow paths so that their flow directions are opposite to each other, and the plurality of circulating flow paths include a supply-side circulating flow path that communicates with the refrigerant supply port and a discharge-side circulating flow path that communicates with the refrigerant discharge port, and among the plurality of circulating flow paths, the supply-side circulating flow path is located nearest to the gas outlet, and the discharge-side circulating flow path is located farthest from the gas outlet, and the center-priority refrigerant flow path structure is an ozone generator including a circular circulation flow path structure that causes the refrigerant to flow through the plurality of circular flow paths and the at least one bent flow path so that the refrigerant is first supplied from the refrigerant supply port to the supply-side circular flow path, and finally discharged from the discharge-side circular flow path through the refrigerant discharge port to the outside.

3. An ozone generator according to claim 2, wherein the refrigerant flow path includes a plurality of partial refrigerant flow paths, each of the plurality of partial refrigerant flow paths having the plurality of circulating flow paths and the at least one bent flow path, the supply-side circulating flow path of each of the plurality of partial refrigerant flow paths communicating with the refrigerant supply port, the discharge-side circulating flow path of each of the plurality of partial refrigerant flow paths communicating with the refrigerant discharge port, and each of the plurality of partial refrigerant flow paths having the circulating flow path structure.

4. An ozone generator according to claim 2 or 3, wherein the refrigerant supply port and the refrigerant discharge port do not overlap the discharge space in a plan view.

5. An ozone generator according to claim 4, wherein the coolant supply port and the coolant discharge port are provided in the same direction relative to the discharge space in a plan view.

6. An ozone generator according to any one of claims 1 to 5, wherein the discharge space is circular in plan view.

7. An ozone generator according to any one of claims 1 to 6, wherein the flow path-integrated metal electrode includes the first metal electrode, and further comprising: an insulating structure provided adjacent to the second metal electrode on the opposite side of the discharge space; and a cooling plate having a cooling function, provided adjacent to the insulating structure on the opposite side of the discharge space.

8. An ozone generator according to claim 7, wherein the cooling plate has a second refrigerant flow path therein for flowing a second refrigerant, the cooling plate has a central cooling region that overlaps with the central discharge space in a plan view, and a peripheral cooling region that overlaps with the peripheral discharge space in a plan view, the second refrigerant flow path is formed from the central cooling region to the peripheral cooling region, and has a second central priority refrigerant flow path structure that flows the second refrigerant into the central cooling region before flowing into the peripheral cooling region.

9. An ozone generation method for generating ozone gas using an ozone generator, the ozone generator comprising: a flat first metal electrode having a gas outlet at its center; a flat second metal electrode arranged opposite the first metal electrode; and at least one electrode dielectric provided between the first and second metal electrodes and adjacent to at least one of the first and second metal electrodes; a discharge space is provided between the first and second metal electrodes in contact with the at least one electrode dielectric, the discharge space including a discharge central space communicating with the gas outlet and a discharge peripheral space existing around the discharge central space; at least one of the first and second metal electrodes is a flow path-integrated metal electrode, the flow path-integrated metal electrode having an electrode central region overlapping with the discharge central space in a plan view and an electrode peripheral region overlapping with the discharge peripheral space in a plan view; the flow path-integrated metal electrode has a refrigerant flow path therein for flowing a refrigerant, the refrigerant flow path being formed from the electrode central region to the electrode peripheral region; (a) applying a voltage between the first and second metal electrodes to generate a dielectric barrier discharge in the discharge space; (b) performing a center-priority coolant flow path setting process in the coolant flow path, causing the coolant to flow to the electrode central region prior to the electrode peripheral region; and (c) obtaining the ozone gas in the discharge space by supplying a raw material gas from the periphery of the discharge peripheral space toward the discharge central space, wherein the ozone gas obtained in the discharge space is output from the discharge central space to the outside via the gas outlet.

10. An ozone generation method according to claim 9, wherein the ozone generator further comprises a refrigerant supply port that receives the refrigerant from the outside and a refrigerant discharge port that discharges the refrigerant to the outside, the refrigerant flow path includes at least one bent flow path that changes a flow direction and a plurality of circulating flow paths that each allow the refrigerant to flow along the flow direction, a pair of adjacent circulating flow paths among the plurality of circulating flow paths are connected via one of the at least one bent flow paths so that their flow directions are opposite to each other, the plurality of circulating flow paths include a supply-side circulating flow path that communicates with the refrigerant supply port and a discharge-side circulating flow path that communicates with the refrigerant discharge port, and of the plurality of circulating flow paths, the supply-side circulating flow path is located nearest to the gas outlet and the discharge-side circulating flow path is located farthest from the gas outlet, and the center-priority refrigerant flow path setting process in step (b) comprises: (b-1) a step of supplying the refrigerant from the refrigerant supply port to the supply-side circulating flow path; and (b-2) and discharging the refrigerant from the discharge-side circular flow path to the refrigerant discharge port, wherein by performing steps (b-1) and (b-2), a circular circulation flow path through which the refrigerant flows is set in the plurality of circular flow paths and the at least one bent flow path in such a manner that, in the refrigerant flow path, the refrigerant is first supplied from the refrigerant supply port to the supply-side circular flow path, and finally, the refrigerant is discharged from the discharge-side circular flow path to the outside via the refrigerant discharge port.

11. A gas supply device comprising: a flat first metal electrode; and a flat second metal electrode arranged opposite the first metal electrode, at least one of the first and second metal electrodes having a gas outlet at its center; at least one electrode dielectric provided between the first and second metal electrodes and adjacent to at least one of the first and second metal electrodes; a discharge space provided between the first and second metal electrodes in contact with the at least one electrode dielectric; a dielectric barrier discharge occurring in the discharge space when a voltage is applied between the first and second metal electrodes; a source gas being supplied to the discharge space via the gas supply port, and ozone gas being obtained when the source gas passes through the discharge space where the dielectric barrier discharge occurs; the discharge space including a discharge central space communicating with the gas supply port and a discharge peripheral space existing around the discharge central space; the source gas being supplied from the discharge central space toward the discharge peripheral space; and an external space communicating with the discharge peripheral space serving as an ozone gas output space; an ozone generator, wherein at least one of the first and second metal electrodes is a flow path-integrated metal electrode, the flow path-integrated metal electrode having an electrode central region that overlaps with the discharge central space in a planar view and an electrode peripheral region that overlaps with the discharge peripheral space in a planar view, the flow path-integrated metal electrode having a refrigerant flow path therein for flowing a refrigerant, the refrigerant flow path being formed from the electrode peripheral region to the electrode central region, the ozone gas obtained in the discharge space is output from the discharge peripheral space to the ozone gas output space, and the refrigerant flow path has a periphery-priority refrigerant flow path structure that causes the refrigerant to flow to the electrode peripheral region before the electrode central region.

12. An ozone generator according to claim 11, further comprising a refrigerant supply port that receives the refrigerant from the outside, and a refrigerant discharge port that discharges the refrigerant to the outside, wherein the refrigerant flow path includes at least one bent flow path that changes the flow direction, and a plurality of circulating flow paths that each flow the refrigerant along the flow direction, wherein a pair of adjacent circulating flow paths among the plurality of circulating flow paths are connected via one of the at least one bent flow paths so that their flow directions are opposite to each other, and the plurality of circulating flow paths include a supply-side circulating flow path that communicates with the refrigerant supply port and a discharge-side circulating flow path that communicates with the refrigerant discharge port, and among the plurality of circulating flow paths, the supply-side circulating flow path is located farthest from the gas supply port, and the discharge-side circulating flow path is located nearest to the gas supply port, and the periphery-priority refrigerant flow path structure is an ozone generator including a circular circulation flow path structure that causes the refrigerant to flow through the plurality of circular flow paths and the at least one bent flow path so that the refrigerant is first supplied from the refrigerant supply port to the supply-side circular flow path, and finally discharged from the discharge-side circular flow path through the refrigerant discharge port to the outside.

13. An ozone generator according to claim 12, wherein the refrigerant flow path includes a plurality of partial refrigerant flow paths, each of the plurality of partial refrigerant flow paths having the plurality of circulating flow paths and the at least one bent flow path, the supply-side circulating flow path of each of the plurality of partial refrigerant flow paths communicating with the refrigerant supply port, the discharge-side circulating flow path of each of the plurality of partial refrigerant flow paths communicating with the refrigerant discharge port, and each of the plurality of partial refrigerant flow paths having the circulating flow path structure.

14. An ozone generator according to claim 12 or 13, wherein the refrigerant supply port and the refrigerant discharge port do not overlap the discharge space in a plan view.

15. An ozone generator according to claim 14, wherein the coolant supply port and the coolant discharge port are provided in the same direction relative to the discharge space in a plan view.

16. An ozone generator according to any one of claims 11 to 15, wherein the discharge space is circular in plan view.

17. An ozone generator according to any one of claims 11 to 16, wherein the flow path-integrated metal electrode includes the first metal electrode, and further comprising: an insulating structure provided adjacent to the second metal electrode on the opposite side of the discharge space; and a cooling plate having a cooling function, provided adjacent to the insulating structure on the opposite side of the discharge space.

18. An ozone generator according to claim 17, wherein the cooling plate has a second refrigerant flow path therein through which a second refrigerant flows, the cooling plate has a central cooling region that overlaps with the central discharge space in a planar view, and a peripheral cooling region that overlaps with the peripheral discharge space in a planar view, the second refrigerant flow path is formed from the peripheral cooling region to the central cooling region, and has a second peripheral-priority refrigerant flow path structure that flows the second refrigerant into the peripheral cooling region prior to the central cooling region.

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