Power supply for ozone generator

Abstract

To obtain a power supply device for an ozone generator capable of preventing condensation on the outer surface of a board case. [Solution] An ozone generator power supply device 50 supplies power to an ozone generator 2 that generates ozone from an oxygen-containing gas by silent discharge. The ozone generator power supply device 50 includes a main heating element 12 including a transformer, an inverter, and a reactor, and a heat exchanger 11 that cools air flowing inside a panel housing 20 with cooling water. At least one of the transformer, the inverter, and the reactor, and the heat exchanger 11 are disposed inside the panel housing 20. An electrically driven valve 16 that controls the flow rate of cooling water flowing in and out of the heat exchanger 11 is connected to the heat exchanger 11, and opening and closing of the electrically driven valve 16 is controlled by a control unit 13.

Description

[Technical field]

[0001] The present disclosure relates to a power supply device for an ozone generator, which is a power supply device for an ozone generator that generates ozone from an oxygen-containing gas by silent discharge. [Background technology]

[0002] A typical power supply device for an ozone generator includes a transformer, a reactor, and an inverter. In a conventional power supply device for an ozone generator that supplies, for example, 100 kW or more of power, the capacity of the transformer, reactor, and inverter is large, and the heat density of these devices is high. For this reason, the inside of the panel housing that houses these devices is sometimes cooled using a heat exchanger. The following Patent Document 1 discloses a small-sized and simply structured power supply device for an ozone generator that optimizes the arrangement and cooling of the devices inside the panel housing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6537737 Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of an ozone generator power supply device that uses a heat exchanger to cool the inside of the panel case, if the temperature of the supplied cooling water is low, the inside of the panel case is cooled, which may cause condensation on the outer surface of the panel case. In the ozone generator power supply device described in Patent Document 1, condensation on the outer surface of the panel case is also mentioned, but there is no guarantee that condensation on the outer surface of the panel case will be prevented.

[0005] The present disclosure has been made in consideration of the above, and has an object to provide a power supply device for an ozone generator that can prevent condensation on the outer surface of a panel housing. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the power supply device for an ozone generator according to the present disclosure is a power supply device for an ozone generator that supplies power to an ozone generator that generates ozone from a gas containing oxygen by silent discharge. The power supply device for an ozone generator includes a transformer that transforms a voltage from a commercial AC power supply, an inverter that converts the AC voltage transformed by the transformer into an AC voltage of a higher frequency, and a reactor connected to the output of the inverter. The power supply device for an ozone generator also includes a panel housing that is a housing that houses at least one of the transformer, the inverter, and the reactor. A heat exchanger that cools the air flowing through the panel housing with cooling water is disposed inside or outside the panel housing adjacent to the panel housing. At least one of the transformer, the inverter, and the reactor housed inside the panel housing is cooled by the air flowing through the panel housing. An electrically driven valve that controls the flow rate of the cooling water flowing in and out of the heat exchanger is connected to the heat exchanger, and the opening and closing of the electrically driven valve is controlled by a control unit. Effect of the Invention

[0007] The power supply device for an ozone generator according to the present disclosure has the effect of preventing condensation on the outer surface of the panel housing. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a configuration example of an ozone generator including an ozone generator power supply device according to a first embodiment. [Diagram 2] FIG. 1 is a left side view of the inside of a power supply device for an ozone generator according to a first embodiment. [Diagram 3] FIG. 3 is an internal side view of an example of a configuration of the power supply device for an ozone generator according to the first embodiment, which is different from that of FIG. 2, as viewed from the left side. [Figure 4] FIG. 3 is a diagram for explaining a preferred monitoring position for the air temperature inside the panel of the power supply device for an ozone generator shown in FIG. [Diagram 5] FIG. 4 is a diagram for explaining a preferable monitoring position of the air temperature inside the panel in the power supply device for an ozone generator shown in FIG. [Figure 6] 1 is a flowchart illustrating the operation of a control unit in the first embodiment. [Figure 7] FIG. 1 is a block diagram showing an example of a hardware configuration for implementing the functions of a control unit according to a first embodiment. [Figure 8] FIG. 11 is a block diagram showing another example of the hardware configuration for implementing the functions of the control unit in the first embodiment. [Figure 9] FIG. 11 is a left side view of the inside of the power supply device for an ozone generator according to the second embodiment. [Figure 10] FIG. 1 is a first diagram for explaining the operation of a power supply device for an ozone generator according to a third embodiment of the present invention; [Figure 11] FIG. 2 is a second diagram for explaining the operation of the power supply device for an ozone generator according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a power supply device for an ozone generator according to an embodiment of the present disclosure will be described in detail with reference to the attached drawings. Note that in the attached drawings, the scale of each component may be depicted differently from the actual scale for ease of understanding or for convenience of drawing.

[0010] Embodiment 1 Fig. 1 is a diagram showing a configuration example of an ozone generator 100 including an ozone generator power supply device 50 according to the first embodiment. The ozone generator power supply device 50 is a power supply device that supplies power to an ozone generator 2. The ozone generator 2 is a device that generates ozone from a gas containing oxygen by silent discharge. As shown in Fig. 1, the ozone generator 100 includes the ozone generator 2 and the ozone generator power supply device 50, and further includes a chiller 1, a flow rate adjustment valve 4, a cooling water circulation pump 5, and a flow meter 6.

[0011] The chiller 1 is a cooling device that cools the ozone generator 2. The chiller 1 cools the ozone generator 2 by causing cooling water to flow in and out of the ozone generator 2. The cooling water that flows in and out of the ozone generator 2 is circulated by a cooling water circulation pump 5.

[0012] The ozone generator power supply device 50 includes a heat exchanger 11, a main heating element 12, a control unit 13, a fan 14, and a temperature detector 15 as main components for supplying the required power to the ozone generator 2. Examples of the main heating element 12 include a transformer, an inverter, and a reactor. The heat exchanger 11, the main heating element 12, the control unit 13, the fan 14, and the temperature detector 15 are housed inside a panel housing 20. The panel housing 20 is a housing that forms an accommodation space for accommodating these components.

[0013] 1 shows an example in which the control unit 13 is housed inside the panel housing 20, but the present invention is not limited to this example. The control unit 13 may be present outside the panel housing 20. For example, a control panel may be provided as a parallel panel next to the panel housing 20, and the control unit 13 may be installed on the control panel. Alternatively, the control unit 13 may be located at a distance within a range in which signals can be exchanged.

[0014] The ozone generator power supply device 50 has a main heat generating element 12 and therefore requires cooling. As shown in Fig. 1, the ozone generator power supply device 50 according to the first embodiment is configured so that a part of the cooling water supplied from the chiller 1 to the ozone generator 2 branches off and flows in and out. That is, the ozone generator power supply device 50 according to the first embodiment is configured to use the cooling water supplied to the ozone generator 2, and is not configured to have a separate cooling device dedicated to the ozone generator power supply device 50.

[0015] The flow rate control valve 4 is a manual control valve. At the beginning of operation of the ozone generator power supply device 50, the flow rate is manually set so that the cooling water flowing in and out of the heat exchanger 11 of the ozone generator power supply device 50 becomes a specified flow rate. The flow rate of the cooling water can be confirmed by the flow meter 6. Meanwhile, during operation of the ozone generator power supply device 50, the flow rate of the cooling water flowing in and out of the heat exchanger 11 is controlled by opening and closing an electrically driven valve 16 connected to the heat exchanger 11 via a pipe. The opening and closing of the electrically driven valve 16 is controlled by the control unit 13. Examples of the electrically driven valve 16 include a solenoid valve driven by a solenoid (electromagnet) and an electric valve driven by a motor. Either a solenoid valve or an electric valve may be used, but a solenoid valve is preferable in terms of instantaneous operation and relatively low cost.

[0016] 1, the flow rate control valve 4 and the electrically driven valve 16 are shown as separate bodies, but the flow rate control valve 4 and the electrically driven valve 16 may be configured as an integrated body. That is, in the configuration of FIG. 1, the flow rate control valve 4 can be omitted, and the configuration may include only the electrically driven valve 16 controlled by the control unit 13.

[0017] In the ozone generator power supply device 50, the white arrows shown in the panel housing 20 indicate the air flow within the panel housing 20. This air flow is caused by the fan 14 and flows into the heat exchanger 11. The heat exchanger 11 cools the flowing air with cooling water. As a result, the air flowing inside the panel housing 20 is cooled by the cooling water flowing in and out of the heat exchanger 11.

[0018] The temperature detector 15 monitors the internal air temperature, which is the temperature of the air flowing through the inside of the panel housing 20, and outputs the monitoring result to the control unit 13. The control unit 13 controls the opening and closing of the electrically driven valve 16 based on the monitoring result of the temperature detector 15. As described above, the flow rate of the cooling water flowing in and out of the heat exchanger 11 is controlled by opening and closing the electrically driven valve 16. That is, in the ozone generator power supply device 50 according to the first embodiment, the control unit 13 controls the flow rate of the cooling water by controlling the opening and closing of the electrically driven valve 16 based on the internal air temperature. Note that the control of the flow rate also includes control of flow / stop, that is, ON / OFF control.

[0019] FIG. 2 is an internal side view of the inside of the ozone generator power supply device 50 according to the first embodiment, seen from the left side. In FIG. 2, the heat exchanger 11 and the fan 14 described with reference to FIG. 1 are shown inside the panel housing 20. FIG. 2 also shows a transformer 121, an inverter 122, and a reactor 123 as examples of the main heating element 12 described in FIG. 1. The transformer 121 transforms the voltage from a commercial AC power supply. The inverter 122 converts the AC voltage transformed by the transformer 121 into an AC voltage of a higher frequency. The reactor 123 is connected to the output of the inverter 122. The ozone generator 2 using silent discharge is capacitive as a load of the ozone generator power supply device 50. For this reason, an inductive reactor 123 is usually provided on the output side of the inverter 122.

[0020] Next, the arrangement of each component will be described with reference to the example of Fig. 2. First, heat exchanger 11 is arranged on the lower side inside panel housing 20. Heat exchanger 11 is arranged with a downward inclination from the front side to the rear side of panel housing 20. The inclination angle is preferably 45 degrees or less with respect to the horizontal direction so that the space occupied by heat exchanger 11 is not large, and more preferably 25 degrees or less.

[0021] On the other hand, the transformer 121 , the inverter 122 and the reactor 123 are disposed on the upper side inside the panel housing 20 .

[0022] The transformer 121 and the inverter 122 are components that generate a large amount of heat. Furthermore, the inverter 122 has a built-in semiconductor element, and sufficient cooling is required to prevent damage to the semiconductor element. Taking these points into consideration, the transformer 121 and the inverter 122 are arranged directly above the heat exchanger 11. By arranging them in this manner, it becomes possible for the transformer 121 and the inverter 122 to be cooled by the coldest cooling air inside the panel housing 20.

[0023] Furthermore, the reactor 123 is disposed above the transformer 121 and the inverter 122, and is cooled using the cooling air that has cooled the transformer 121 and the inverter 122. A reactor mounting plate (not shown) is provided below the reactor 123, and an opening is provided in a portion of the reactor mounting plate that is below the reactor 123 to allow the cooling air to flow. Although the temperature of the cooling air hitting the reactor 123 is rising, most of the cooling air flowing inside the panel housing 20 can be used to cool the reactor 123, so the reactor 123 can be sufficiently cooled.

[0024] A heat exchanger mounting plate 17 is provided directly above the heat exchanger 11 so as to close the gap between the panel housing 20 and the heat exchanger 11. The heat exchanger mounting plate 17 is provided so that the cooling air introduced from the return air passage 19 into the lower part of the panel housing 20 flows to the upper part of the panel housing 20 via the heat exchanger 11. The return air passage 19 is an air passage for circulating the air inside the panel after cooling the transformer 121, the inverter 122, and the reactor 123.

[0025] The fan 14 is disposed at a position inside the front panel 22. In addition, a grounded protective panel 18 is disposed between the fan 14 and the inverter 122. The return air passage 19 is formed by the protective panel 18 and the front panel 22 of the panel housing 20.

[0026] Although a high voltage is applied to the inverter 122, providing a grounded protective panel 18 can prevent an operator from accidentally coming into contact with residual high voltage, for example, when replacing the fan 14. In addition, the protective panel 18 and the front panel 22 of the panel housing 20 can form the return air passage 19, eliminating the need for special structural members dedicated to the air passage. This allows the panel housing 20 to be made smaller, simpler, and less expensive.

[0027] The transformer 121 is disposed, for example, at a distance of about 5 mm to 50 mm from the inner surface of the rear panel 21. With this arrangement, the rear panel 21 of the panel housing 20 can also be used as a partition of the air passage, and cooling air can be actively circulated to the inside or outer surface of the transformer 121. In addition, the distance between the transformer 121 and the inverter 122, and the distance between the inverter 122 and the protective panel 18 are also disposed at a distance of about 5 mm to 50 mm. With this arrangement, the space between the transformer 121 and the inverter 122, and the front side of the inverter 122 can also be used as an air passage, and cooling air can be actively circulated to the inside and outer surfaces of the transformer 121 and the inverter 122. It goes without saying that the distance between the rear panel 21 of the panel housing 20 and the transformer 121 is at least the length of the insulation distance required in consideration of the voltage applied to the transformer 121.

[0028] The configuration in Fig. 2 is merely an example, and the arrangement of the components in the ozone generator power supply device 50 according to the first embodiment is not limited to the example in Fig. 2. For example, while the fan 14 is disposed on the front panel 22 side in Fig. 2, the fan 14 may be disposed so as to be located on the rear panel 21 side. Alternatively, the fan 14 may be disposed so as to be located on the right side panel side or the left side panel side not shown in Fig. 2.

[0029] 2 illustrates a configuration in which the transformer 121, the inverter 122, and the reactor 123 are disposed on the upper side inside the panel housing 20, and the heat exchanger 11 is disposed on the lower side inside the panel housing 20, but the configuration is not limited to this. For example, the heat exchanger 11 may be disposed at the position of the fan 14 in FIG. 2, and the fan 14 may be disposed above the heat exchanger 11. This configuration is shown in FIG. 3. FIG. 3 is an interior side view of an example of a configuration of the ozone generator power supply device 50 according to the first embodiment, which is different from that in FIG. 2, as seen from the left side. In FIG. 3, components that are the same as or equivalent to those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2. In FIG. 3, the air flow in the panel housing 20 is indicated by an outlined arrow, as in FIG. 2.

[0030] In the case of the configuration of FIG. 3, the protective panel 18 is not necessary, and a panel 40 constituting a part of the panel housing 20 is present at a position corresponding to the protective panel 18. An opening 41 is provided at the top of the panel 40, and an opening 42 is provided at the bottom of the panel 40. Also, in FIG. 3, a new housing 44 for forming the return air passage 19 is installed outside the panel 40, that is, adjacent to the outside of the panel housing 20. The fan 14 is installed in the opening 41 provided at the top of the panel 40. The heat exchanger 11 is installed inside the new housing 44 for forming the return air passage 19, and the heat exchanger mounting plate 17 blocks the entrance of the gap so that the air inside the panel that has passed through the opening 41 does not flow into the gap around the heat exchanger 11. The opening 41 and the opening 42 allow the air inside the panel to circulate between the panel housing 20 and the housing 44.

[0031] 2 and 3 show an example of a configuration in which the transformer 121, the inverter 122, and the reactor 123 are all housed inside the panel housing 20, but at least one of the transformer 121, the inverter 122, and the reactor 123 may be housed inside the panel housing 20. In other words, the main heat generating element 12 cooled by air flowing inside the panel housing 20 may be at least one of the transformer 121, the inverter 122, and the reactor 123.

[0032] 2 and 3, the transformer 121, the inverter 122, and the reactor 123 are each configured as one unit, but each of these units may be configured as a plurality of units.

[0033] FIG. 4 is a diagram for explaining a preferred monitoring position of the air temperature inside the panel in the ozone generator power supply device 50 shown in FIG. 2. FIG. 4 shows a space 26 indicating a preferred monitoring position of the air temperature inside the panel, a space 27 indicating a more preferred monitoring position of the air temperature inside the panel, and a space 30 indicating an even more preferred monitoring position of the air temperature inside the panel. The space 30 is shown with fine hatching, and the space 27 is shown with coarse hatching. The space 27 includes the range of the space 30, and the space 26 includes the ranges of the space 27 and the space 30. In this paper, in order to distinguish the spaces 26, 27, and 30 without reference numbers, the space 26 may be called the "first space", the space 27 may be called the "second space", and the space 30 may be called the "third space".

[0034] In the first embodiment, in order to monitor the air temperature inside the panel, the temperature detector 15 is installed in the space 26. In the example of FIG.

[0035] The space 26 is a space inside the panel housing 20, which is formed above the top end of the main heat generating part of the main heat generating element 12 including the transformer 121, the inverter 122, and the reactor 123, and is a space in a cross section seen to the right or left of the return air passage 19 for circulating the air inside the panel after cooling the main heat generating element 12. Here, the main heat generating part of the main heat generating element 12 is a part whose heat generation amount is, for example, 10% or more of the heat generation amount of the entire main heat generating element 12. In other words, even if a part such as a protrusion whose heat generation amount is less than 10% of the total is included in the space 26, the part is not considered to be a main heat generating part. Therefore, the part such as the protrusion may be included in the space 26. Note that 10% mentioned here is an example, and is not limited to this numerical value. For example, instead of 10%, 8% or 12% may be used.

[0036] To prevent condensation on the outer surface of the panel housing 20, a possible method is to monitor the temperature of the area where condensation is to be prevented and control the cooling water so that the temperature of the area is 1 to 2°C higher than the dew point temperature, that is, to control the temperature of the area where condensation is to be prevented to be slightly higher than the dew point temperature. However, this method has the problem that it is not possible to grasp the temperature behavior of the main heating element 12, which is the object to be cooled, and therefore the main heating element 12 may overheat due to an unexpected temperature rise, shortening the lifespan of the main heating element 12.

[0037] In contrast, the method of the first embodiment is a method in which the monitoring position of the air temperature inside the panel is set above the uppermost end of the main heat generating part of the main heat generating body 12 including the transformer 121, the inverter 122, and the reactor 123. This method makes it possible to monitor the temperature inside the panel after passing through the main heat generating body 12, which is the object to be cooled. That is, the method of the first embodiment is a method of controlling the cooling water by monitoring the temperature of the place where the temperature behavior of the main heat generating body 12 can be reflected. The space 26 is the place where the temperature behavior of the main heat generating body 12 can be most comprehensively reflected, including the case where there are multiple main heat generating bodies 12. On the other hand, the temperature of the lower part of the rear side of the panel housing 20, where condensation is most likely to occur, is affected by both the cooling water temperature and the air temperature entering the heat exchanger 11 when the cooling water is flowing, and is affected by the air temperature entering the heat exchanger 11 when the cooling water is not flowing. In the flow of the air inside the panel, since the main heat generating body 12 does not exist downstream of the space 26, the temperature of the space 26 is almost equal to the air temperature entering the heat exchanger 11. That is, when the temperature detector 15 is disposed in the space 26, the temperature detector 15 can obtain information on a temperature that affects both the temperature of the main heating element 12 and the temperature of the lower part of the rear side of the panel housing 20 where condensation is most likely to occur. Therefore, the ozone generator power supply device 50 according to the first embodiment has the effect of preventing both the overheating of the main heating element 12 and condensation on the panel housing 20.

[0038] Moreover, the space 27, which is the second space, indicates a more preferable monitoring position for the air temperature inside the panel than the space 26, which is the first space. The space 27 is the space inside the panel housing 20 on the return air passage 19 side of the vertical imaginary plane 28 that divides the space 26 that houses the main heating element 12 excluding the return air passage 19 into two, that is, the space inside the panel housing 20 on the fan 14 side of the imaginary plane 28. It is considered that the air passing through the reactor 123 and heading toward the return air passage 19 passes through the space 27 more than the space 26 that does not include the space 27. For this reason, it can be considered that the space 27 is a place that can reflect the temperature behavior of the main heating element 12 more than the space 26.

[0039] Moreover, the space 30, which is the third space, indicates a more preferable monitoring position for the air temperature inside the panel than the space 27, which is the second space. The space 30 is the space 27, and is a space inside the panel housing 20 that is closer to the return air duct 19 than the imaginary plane 31 that is parallel to the vertical imaginary plane 28 at the position on the return air duct 19 side of the outer casing of the main heating element 12 (in the example of FIG. 4, the reactor 123) that is arranged at the top of the panel housing 20, that is, a space inside the panel housing 20 that is closer to the fan 14 than the imaginary plane 31. The air that passes through the reactor 123 and heads toward the return air duct 19 always passes through the space 30 eventually. For this reason, the space 30 can be considered to be a place that can reflect the temperature behavior of the main heating element 12 more than the space 27. In this paper, in order to distinguish the imaginary planes 28 and 31 without a reference symbol, the imaginary plane 28 may be called the "first imaginary plane" and the imaginary plane 31 may be called the "second imaginary plane".

[0040] In addition, the ozone generator power supply device 50 may be conventionally provided with a temperature detector for the purpose of an alarm, for example. In this case, the temperature detector may be used instead of the temperature detector 15 as long as the temperature detector is disposed at a position that can reflect the temperature behavior of the main heating element 12 to be cooled.

[0041] Fig. 5 is a diagram for explaining a preferred monitoring position for the air temperature inside the panel in the ozone generator power supply device 50 shown in Fig. 3. As in Fig. 3, Fig. 5 shows a space 26 indicating a preferred monitoring position for the air temperature inside the panel, a space 27 indicating a more preferred monitoring position for the air temperature inside the panel by coarse hatching, and a space 30 indicating an even more preferred monitoring position for the air temperature inside the panel by fine hatching. Fig. 5 shows an example in which the temperature detector 15 is installed in the space 30, but the concept regarding the monitoring position for the air temperature inside the panel is the same as that of the ozone generator power supply device 50 shown in Fig. 4, and the temperature detector 15 may be installed in any of the spaces 26, 27, and 30.

[0042] Next, the operation of the control unit 13 in the first embodiment will be described with reference to Fig. 6. Fig. 6 is a flow chart for explaining the operation of the control unit 13 in the first embodiment. In explaining Fig. 6, the environmental conditions according to the specifications are an internal air temperature of 30°C, a relative humidity of 85%, and a dew point temperature of 27.5°C. Also, while the ozone generator power supply device 50 is stopped, the electrically driven valve 16 is controlled to be closed.

[0043] First, when the operation of the ozone generator power supply device 50 is started with the electrically driven valve 16 closed, the cooling water does not flow, and the heat generated by the main heating element 12 causes the air temperature inside the panel to rise. The control unit 13 judges whether the air temperature inside the panel is 40° C. or higher (step S11). If the air temperature inside the panel is less than 40° C. (step S11, No), the control unit 13 returns to step S11 and repeats the process of step S11. That is, the process of step S11 is repeated until the air temperature inside the panel is 40° C. or higher. If the air temperature inside the panel is 40° C. or higher (step S11, Yes), the control unit 13 controls the electrically driven valve 16 to open (step S12). Note that in step S11, the case where the air temperature inside the panel is 40° C. is judged as “Yes”, but the case where the air temperature inside the panel is 40° C. may be judged as “No”. That is, the case where the air temperature inside the panel is equal to the judgment value 40° C. may be judged as either “Yes” or “No”.

[0044] When the electrically driven valve 16 is opened, the cooling water flows into the heat exchanger 11, and the air temperature inside the panel drops. The control unit 13 judges whether the air temperature inside the panel is 39°C or lower (step S13). If the air temperature inside the panel exceeds 39°C (step S13, No), the control unit 13 returns to step S13 and repeats the process of step S13. That is, the process of step S13 is repeated until the air temperature inside the panel is 39°C or lower. Also, if the air temperature inside the panel is 39°C or lower (step S13, Yes), the control unit 13 controls the electrically driven valve 16 to close (step S14). Note that in step S13, the case where the air temperature inside the panel is 39°C is judged as "Yes", but it may be judged as "No". That is, the case where the air temperature inside the panel is equal to the judged value 39°C may be judged as either "Yes" or "No".

[0045] When the electrically driven valve 16 is closed, the cooling water stops flowing to the heat exchanger 11, and the air temperature inside the panel rises. The control unit 13 checks whether or not an interrupt process has occurred (step S15), and if an interrupt process has occurred (step S15, Yes), ends the process in Fig. 6. If an interrupt process has not occurred (step S15, No), the control unit 13 returns to step S11 and repeats the processes of steps S11 to S15.

[0046] A supplementary explanation of the processing in Fig. 6 will be provided. According to the processing in Fig. 6, when the air temperature inside the panel reaches 40°C, the electrically driven valve 16 opens and cooling water starts to flow. As the cooling water flows, the air temperature inside the panel drops, and the cooling water continues to flow until the air temperature inside the panel reaches 39°C, at which point the electrically driven valve 16 closes and the cooling water stops. When the cooling water stops, the air temperature inside the panel rises and eventually reaches 40°C. These processing steps are then repeated.

[0047] When the load of the ozone generator power supply device 50 is very low, for example, and the air temperature inside the panel does not reach 40°C, the electrically driven valve 16 can be kept closed without any problem. It has been confirmed that the temperature inside the main heating element 12 is equal to or lower than the allowable upper limit temperature until the air temperature inside the panel reaches 40°C. It has also been confirmed that, if the air temperature inside the panel is 39°C or higher, the temperature of any part of the outer surface of the panel housing 20, particularly the lower part of the back panel 21 where condensation is most likely to occur, is 28.5°C or higher. As described above, the dew point temperature is 27.5°C, so condensation does not occur. When the ozone generator power supply device 50 is started from a stopped state, there is a period in which the air temperature inside the panel is 39°C or lower during the period from the start to step S11 in FIG. 6, but since cooling water does not flow during this period in logic, condensation does not occur even if the air temperature inside the panel is 39°C or lower.

[0048] 6 shows an example in which the control temperature difference of the air temperature inside the panel is set to 1.0°C (=40-39°C), but this is merely an example and is not limited to this example. The control temperature difference of the air temperature inside the panel can be set preferably to 0.3°C or more and 2°C or less, more preferably to 0.5°C or more and 1.5°C or less, and even more preferably to 0.7°C or more and 1.2°C or less.

[0049] If the control temperature difference of the air temperature inside the panel is too small, the electrically driven valve 16 opens and closes more frequently, shortening the life of the electrically driven valve 16. If the control temperature difference is too large, the electrically driven valve 16 opens for a longer time, causing the panel housing 20 to become too cold and making condensation more likely to occur. The above setting value for the control temperature difference takes these points into consideration, and makes it possible to prevent condensation on the panel housing 20 while extending the life of the electrically driven valve 16.

[0050] Fig. 7 is a block diagram showing an example of a hardware configuration for realizing the functions of control unit 13 in embodiment 1. When part or all of the functions of control unit 13 in embodiment 1 are to be realized, a configuration including processor 300 for performing calculations, memory 302 for storing programs read by processor 300, and interface 304 for inputting and outputting signals can be used, as shown in Fig. 7. The functions including processor 300, memory 302, and interface 304 may be configured using, for example, a programmable logic controller (PLC).

[0051] The processor 300 is an example of a computing means. The processor 300 may be a computing means called a microprocessor, a microcomputer, a CPU (Central Processing Unit), or a DSP (Digital Signal Processor). Examples of the memory 302 include a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable ROM), or an EEPROM (Electrically EPROM), a magnetic disk, an optical disk, a compact disk, a mini disk, and a DVD (Digital Versatile Disc).

[0052] The memory 302 stores a program that executes the functions of the control unit 13 in the first embodiment. The processor 300 receives and transmits necessary information via the interface 304, executes the program stored in the memory 302, and refers to the table stored in the memory 302, thereby performing the above-mentioned processing. The calculation results by the processor 300 can be stored in the memory 302.

[0053] Furthermore, when part of the functions of the control unit 13 in the first embodiment is to be realized, a configuration shown in Fig. 8 may be used. Fig. 8 is a block diagram showing another example of a hardware configuration for realizing the functions of the control unit 13 in the first embodiment. In Fig. 8, the processor 300 and memory 302 shown in Fig. 5 are replaced with a processing circuit 303.

[0054] The processing circuit 303 may be a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination of these. Information input to the processing circuit 303 and information output from the processing circuit 303 can be exchanged via an interface 304.

[0055] It is also possible that a part of the processing in the control unit 13 is performed by the processing circuit 303 , and the processing that is not performed by the processing circuit 303 is performed by the processor 300 and the memory 302 .

[0056] As described above, in the power supply device 50 for an ozone generator according to the first embodiment, the transformer 121, the inverter 122, and the reactor 123 are disposed in the upper part of the inside of the panel housing 20, which is a housing that houses these components, and the heat exchanger 11 that cools the air flowing through the inside of the panel housing 20 with cooling water is disposed in the lower part of the inside of the panel housing 20. The heat exchanger 11 is connected to the electrically driven valve 16 that controls the flow rate of the cooling water flowing in and out of the heat exchanger 11, and the opening and closing of the electrically driven valve 16 is controlled by the control unit 13. According to the power supply device 50 for an ozone generator configured in this manner, the first space formed in the panel housing 20 above the transformer 121, the inverter 122, and the reactor 123 can be set as a monitoring position for the in-panel air temperature, and the opening and closing of the electrically driven valve 16 is controlled based on the monitoring result of the in-panel air temperature in this first space, so that it is possible to prevent condensation on the outer surface of the panel housing 20.

[0057] Embodiment 2 Fig. 9 is an interior side view of the inside of the ozone generator power supply device 50 according to the second embodiment, as viewed from the left side. The difference from the ozone generator power supply device 50 according to the first embodiment shown in Fig. 2 is the position of the temperature detector 15. Specifically, in the ozone generator power supply device 50 shown in Fig. 9, the temperature detector 15 is disposed in a return air passage 19 formed by the protective panel 18 and the front panel 22 of the board housing 20. Note that, in the example of Fig. 9, the temperature detector 15 is disposed on the exhaust side of the fan 14, but is not limited to this example. The temperature detector 15 may be disposed on the intake side of the fan 14.

[0058] In the return air passage 19, air flows after passing through the main heating element 12 including the transformer 121, the inverter 122, and the reactor 123 to be cooled. For this reason, it can be said that the return air passage 19 is a place where the temperature behavior of the main heating element 12 can be reflected. Therefore, by disposing the temperature detector 15 in the return air passage 19, the temperature detector 15 can obtain information on the temperature that affects both the temperature of the main heating element 12 and the temperature of the lower part of the rear side of the panel housing 20 where condensation is most likely to occur. Therefore, according to the power supply device 50 for an ozone generator according to the second embodiment, similarly to the power supply device 50 for an ozone generator according to the first embodiment, it is possible to obtain an effect of preventing both the overheating of the main heating element 12 and the condensation of the panel housing 20.

[0059] In this embodiment, the temperature detector 15 is disposed in the return air duct 19 of the ozone generator power supply device 50 shown in Fig. 2, but the present invention is not limited to this example. The temperature detector 15 may be disposed on the exhaust side or intake side of the return air duct 19 of the ozone generator power supply device 50 shown in Fig. 3. In either configuration, the effects according to the second embodiment described above can be obtained.

[0060] Embodiment 3 In the third embodiment, a power supply device 50 for an ozone generator will be described which can obtain the same effects as those of the first and second embodiments without using a temperature detector 15. The configuration of the power supply device 50 for an ozone generator according to the third embodiment is the same as those of the first and second embodiments, except that the temperature detector 15 is not included.

[0061] FIG. 10 is a first diagram for explaining the operation of the ozone generator power supply device 50 according to the third embodiment. FIG. 10 shows, in the form of a table, an electrically driven valve open time and an electrically driven valve close time that are set corresponding to the load factor of the ozone generator power supply device 50. In FIG. 10, the load factor is the ratio of the power output from the ozone generator power supply device 50 to the ozone generator 2, which is a load, to the rated power of the ozone generator power supply device 50. Note that the load factor may be defined based on the maximum power that the ozone generator power supply device 50 can output, instead of the rated power. The set values ​​shown in FIG. 10 can be held in the control unit 13.

[0062] In FIG. 10, for example, when the load factor is constant at 100%, the electrically driven valve 16 is controlled to be open for 350 seconds and closed for 60 seconds, and these controls are repeated.

[0063] Moreover, Fig. 11 is a second diagram for explaining the operation of the ozone generator power supply device 50 according to the third embodiment. Fig. 11 shows an example of operation when actually operated using the set values ​​in Fig. 10, with the load factor shown on the upper side and the open / closed state of the electrically driven valve 16 shown on the lower side. Note that Fig. 11 takes into consideration the case where the load factor is not constant but changes during control by the control unit 13. The example of operation in Fig. 11 will be explained below.

[0064] First, in FIG. 11, the load factor at time 0 seconds is 45%, and therefore the set value for opening at a load factor of 45% in FIG. 10 is 100 seconds, so the electrically driven valve 16 is opened for 100 seconds and then closed. If the load factor does not change, the set value for closing at a load factor of 45% is 400 seconds, so the closed state continues for 400 seconds. On the other hand, in the example of FIG. 11, the load factor changes to 55% at time 300 seconds, so the electrically driven valve 16 is controlled to be closed for 350 seconds. 200 seconds out of the 350 seconds is the elapsed time from 100 seconds when the electrically driven valve 16 was closed to 300 seconds when the load factor changed to 55%, that is, 300-100=200 seconds. The remaining 150 seconds out of the 350 seconds are calculated as 300 seconds * (1 / 2) = 150 seconds. 300 seconds is the set value for closing at a load factor of 55%. Additionally, (1 / 2) is the remaining ratio of the elapsed time, which is the value obtained by subtracting the ratio of the elapsed time from 1. Of the set value of 400 seconds for closing when the load factor is 45%, 200 seconds have elapsed by the time the load factor changes to 55%, so the ratio of the elapsed time is 200 / 400=1 / 2, and the remaining ratio of the elapsed time is 1-(1 / 2)=1 / 2. The aforementioned 150 seconds can be calculated by multiplying this remaining ratio by 300 seconds. In this way, the electrically driven valve 16 remains closed from time 100 seconds to 350 seconds, that is, until time 450 seconds.

[0065] 450 seconds after the start of control, the electrically driven valve 16 is controlled to the open state, and this open time can also be calculated in the same manner as above. In the example of FIG. 11, the load factor changes to 65% 500 seconds after the start of control, so the electrically driven valve 16 is controlled to the open state for 183 seconds. 50 seconds of the 183 seconds is the elapsed time from 450 seconds, when the electrically driven valve 16 is opened, to 500 seconds, when the load factor changes to 65%, that is, 500-450=50 seconds. The remaining 133 seconds of the 183 seconds are calculated as 200 seconds * (2 / 3) ≒ 133 seconds. 200 seconds is the open setting value for a load factor of 65%, and (2 / 3) is the remaining proportion of the elapsed time. Of the set open time of 150 seconds at a load factor of 55%, 50 seconds have elapsed by the time the load factor changes to 65%, so the ratio of the elapsed time is 50 / 150=1 / 3, and the remaining ratio of the elapsed time is 1-(1 / 3)=2 / 3. The aforementioned 133 seconds can be calculated by multiplying this remaining ratio by 200 seconds. In this way, the electrically driven valve 16 remains open from time 450 seconds to 183 seconds, that is, until time 633 seconds.

[0066] After that, since the load factor does not change, the opening and closing of the electrically driven valve 16 is controlled based on the closing time setting of 200 seconds when the load factor is 65% and the opening time setting of 200 seconds when the load factor is 65%.

[0067] As described above, when the load rate changes during control by the control unit 13, the opening and closing time of the electrically driven valve 16 is first considered to be 100% for the electrically driven valve open time or the electrically driven valve closed time in each load rate range. Then, even if the load rate changes, the percentage of time for which the electrically driven valve 16 is controlled to be open or closed at each load rate is accumulated, and the electrically driven valve open time or the electrically driven valve closed time until the accumulated time reaches 100% is obtained. In this way, it becomes possible to calculate the electrically driven valve open time or the electrically driven valve closed time without using a future load rate that cannot be known at the time of control.

[0068] Although Fig. 11 shows an example in which the load factor changes stepwise, similar calculations are possible in the case of continuous change, since this corresponds to one of the rows in the table of Fig. 10. Also, Fig. 10 shows the switching times versus the load factor in table format, but it may be specified by a function or the like.

[0069] As described above, in the ozone generator power supply device 50 according to the third embodiment, the control unit 13 controls the flow rate of the cooling water by controlling the opening and closing of the electrically driven valve 16 according to the predetermined closing time and opening time. Compared with the first and second embodiments, the ozone generator power supply device 50 according to the third embodiment has the advantage that it is not necessary to monitor the air temperature inside the panel and the temperature detector 15 is not necessary.

[0070] In the ozone generator power supply device 50 according to the third embodiment, the opening and closing control of the electrically driven valve 16 can be performed based on the load factor of the ozone generator 2. The load factor of the ozone generator 2 can be easily grasped. In addition, since the ozone generator power supply device 50 has the control unit 13, the method according to the third embodiment can be simply and easily implemented in the ozone generator power supply device 50. According to the ozone generator power supply device 50 according to the third embodiment, as in the first and second embodiments, it is possible to obtain an effect of preventing both the main heating element 12 from overheating and condensation on the panel housing 20.

[0071] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or the embodiments may be combined with each other. Also, parts of the configurations may be omitted or modified without departing from the spirit of the invention. [Explanation of symbols]

[0072] 1 chiller, 2 ozone generator, 4 flow control valve, 5 cooling water circulation pump, 6 flow meter, 11 heat exchanger, 12 main heating element, 13 control unit, 14 fan, 15 temperature detector, 16 electrically driven valve, 17 heat exchanger mounting plate, 18 protective panel, 19 return air duct, 20 panel housing, 21 rear panel, 22 front panel, 26, 27, 30 space, 28, 31 virtual surface, 40 panel, 41, 42 opening, 44 housing, 50 power supply for ozone generator, 100 ozone generator, 121 transformer, 122 inverter, 123 reactor, 300 processor, 302 memory, 303 processing circuit, 304 interface.

Claims

1. A power supply device for an ozone generator, comprising: a transformer for transforming a voltage from a commercial AC power supply; an inverter for converting the AC voltage transformed by the transformer into an AC voltage of a higher frequency; a reactor connected to an output of the inverter; and a panel case that is a case that houses at least one of the transformer, the inverter, and the reactor, the power supply device supplying power to an ozone generator that generates ozone from a gas containing oxygen by silent discharge, A heat exchanger is disposed inside the panel housing or on the adjacent outside thereof, the heat exchanger cooling air flowing through the panel housing with cooling water; At least one of the transformer, the inverter, and the reactor housed inside the panel housing is cooled by air flowing through the panel housing; an electrically driven valve for controlling a flow rate of the cooling water flowing in and out of the heat exchanger is connected to the heat exchanger; The opening and closing of the electrically driven valve is controlled by a control unit.

1. A power supply device for an ozone generator.

2. The control unit controls the flow rate of the cooling water based on an internal air temperature of the panel, which is the temperature of the air flowing through the inside of the panel housing.

2. The power supply device for an ozone generator according to claim 1.

3. A first space formed above the uppermost end of a main heat generating portion of a main heat generating element including the transformer, the inverter, and the reactor is set as a monitoring position for the air temperature inside the panel.

3. The power supply device for an ozone generator according to claim 2.

4. A return air passage is formed for circulating the air inside the panel after cooling the main heat generating element, and in a cross section looking to the right or left of the return air passage, The monitoring position of the air temperature inside the panel is the second space in the panel housing, which is the first space and is located on the return air duct side of a first imaginary plane that divides the space accommodating the main heat generating element excluding the return air duct into two vertical spaces.

4. The power supply device for an ozone generator according to claim 3.

5. The monitoring position of the air temperature inside the panel is the second space, which is a third space inside the panel housing that is parallel to the first imaginary plane at a position on the return air duct side of the outer casing of the main heating element arranged at the top inside the panel housing and is on the return air duct side of a second imaginary plane on the return air duct side.

5. The power supply device for an ozone generator according to claim 4.

6. A return air passage is formed for circulating the air in the panel after cooling the main heat generating elements including the transformer, the inverter, and the reactor, The return air duct is used as a monitoring position for the air temperature inside the panel.

3. The power supply device for an ozone generator according to claim 2.

7. A temperature detector is installed at the monitoring position.

7. The power supply device for an ozone generator according to claim 3, wherein the power supply device is a power supply for an ozone generator.

8. The control unit controls the flow rate of the cooling water by controlling opening and closing of the electrically driven valve based on the detection value of the temperature detector.

8. The power supply device for an ozone generator according to claim 7.

9. The control temperature difference of the air temperature inside the panel, which controls the opening and closing of the electrically driven valve, is set to 0.3° C. or more and 2° C. or less.

9. The power supply device for an ozone generator according to claim 8.

10. The control unit controls the flow rate of the cooling water by controlling opening and closing of the electrically driven valve in accordance with a predetermined closing time and opening time.

2. The power supply device for an ozone generator according to claim 1.

11. The control unit changes the closing time and the opening time based on a load factor of the ozone generator.

11. The power supply device for an ozone generator according to claim 10.

12. The ozone generator is cooled by a chiller; A part of the cooling water supplied from the chiller to the ozone generator is branched and flows in and out of the heat exchanger.

12. A power supply device for an ozone generator according to claim 1, wherein the power supply device is a power supply for an ozone generator.

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