JP4238178B2 - Ozone generator - Google Patents

Description

  The present invention relates to an ozone generator, and more particularly to an ozone generator that is supplied with electric power by an inverter with constant output current control.

Since ozone has a strong oxidizing power and is non-polluting, it is widely applied in the field of water treatment.
And ozone is produced | generated by the silent discharge in an ozone generator using dry air or oxygen as a raw material.

A conventional ozone generator employs an inverter with a constant output current control system as an inverter for an ozone generator that is a capacitor load (see, for example, Patent Document 1).
In the case of an inverter with a constant output current control method, even if the glass electrode tube constituting the ozone generator is broken and the ozone generator becomes abnormal, the inverter operates normally because the output current of the inverter is controlled to be constant. Therefore, the inverter itself could not detect the abnormality of the ozone generator.

JP 2003-267703 A

Thus, in the ozone generator of Patent Document 1 described above, in order to detect an abnormality in the ozone generator, the determination is made by comparing the input power of the inverter with respect to the output current of the inverter. Is required to input to the controller.
For this reason, there is a problem that the cost is increased, the circuit is complicated, the reliability of the apparatus is lowered, and further, it takes much time to adjust the current converter.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an ozone generator that can detect an abnormality of an ozone generator with a simple configuration for improving reliability.

  An ozone generator according to the present invention includes an ozone generator that generates ozone by an electric output applied from an inverter having a constant output current control for receiving a predetermined electric input and converting it into an electric output having a desired frequency. When the output current command value of the inverter is equal to or greater than a specified value and the input power of the inverter is lower than the specified value, an abnormality signal related to the ozone generator is output. An abnormal signal output means is provided.

  According to this invention, the ozone generator which can detect abnormality of an ozone generator with the simple structure which aims at a reliability improvement can be obtained.

Embodiment 1 FIG.
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram showing a configuration of an ozone generator according to Embodiment 1. In FIG. FIG. 2 is an explanatory diagram showing the principle of ozone generation in the ozone generator in the first embodiment. FIG. 3 is a characteristic line showing the same input power characteristic with respect to the output current command value of the inverter and the specified value of the inverter output current command value and the specified value of the same input power in the ozone generator with an ozone generation amount of 250 g / h in the first embodiment. FIG.

In FIG. 1, AC power is supplied to an ozone generator 1 from an inverter 2 as an inverse conversion device via a transformer 3. An equivalent circuit of the ozone generator 1 includes a capacitor 1a made of a dielectric, a capacitor 1b made of a discharge space, and Zener diodes 1c and 1d that consume active power when ozone is generated by silent discharge.
The control device 4 receives the detection signal of the power converter output detector 5a that detects the output power of the power converter 5 as a forward converter for supplying the input power to the inverter 2, that is, the input power to the inverter 2. The The control device 4 is provided with an output current indicator 6 of the inverter 2.
In the control device 4, the current command value of the inverter output current indicator 6 and the output signal of the power converter output detector 5a for detecting the input power to the inverter 2 are connected to the current comparator 4a and the power comparator 4b. .

Here, when it is detected in the current comparator 4a that the inverter output current command value is greater than or equal to the specified value, and the power comparator 4b detects that the inverter input power is lower than the specified value, A logical expression is incorporated so that the output of the control device 4 is turned ON and an abnormal signal of the ozone generator 1 is generated.
That is, in the current comparator 4a, a current command value I _d by the current indicator 6 for indicating the inverter output current command value is compared with the specified value I ₀ of the current command, the inverter output current command value I _d is a specified value When the state is _{equal to} or higher than I ₀ (I _d ≧ I ₀ ), the ON operation is performed to derive the signal output S ₁ . In current comparator 4b, and the detection output value P _d by the power converter output detector 5a for detecting the inverter input power value is compared with the specified value P ₀ of the inverter input power, the inverter input power P _d is the specified value When it is lower than P ₀ (P _d <P ₀ ), the ON operation is performed to derive the signal output S ₂ . AND circuits 4c as a logic operation circuit derives the logical product operation result of the signal output S ₂ of the signal output S ₁ and the current comparator 4b of the current comparator 4a, the inverter output current command value I _d is the prescribed value I _When the state is equal to or greater than ₀ (I _d ≧ I ₀ ) and the inverter input power value P _d is lower than the specified value P ₀ (P _d <P ₀ ), the output of the control device 4 An abnormal signal SA is sent out.

  FIG. 2 shows the principle of ozone generation in the ozone generator 1. When an alternating high voltage is applied between the high voltage electrode 7 and the ground electrode 9, the dielectric 8 provided on the high voltage electrode 7 and the ground electrode 9 Silent discharge occurs during the period of time, and the supply of the raw material gas flow indicated by the arrow A generates the ozone gas flow indicated by the arrow B.

Next, the operation will be described.
As shown in FIG. 1, a power source of 50 Hz or 60 Hz at 3φ200V is input to the inverter 2, and a current of 1φ1 kHz is output by the inverter 2. Since the ozone generator 1 is a capacitor load, a high voltage is applied to the ozone generator 1 via the transformer 3.
When a high voltage is applied to the ozone generator 1, an alternating voltage is applied between the electrodes 7 and 9 via the dielectric 8 (FIG. 2), and silent discharge occurs. When electric energy is applied to the oxygen in the discharge space and activated, a part of the dissociated or excited oxygen changes to ozone, and the ozone generator 1 generates ozone using oxygen as a raw material. The ozone generator consumes active power when generating ozone by silent discharge.

Based on the current command value from the output current indicator 6 of the control device 4, the output current of the inverter 2 increases / decreases, and the effective power consumed by the ozone generator 1 also increases / decreases.
FIG. 3 shows an example of the input power characteristic with respect to the output current command value of the inverter 2, the specified value of the inverter output current command value, and the specified value of the input power for an ozone generator with an ozone generation amount of 250 g / h. The operating conditions of the ozone generator when the rated ozone is generated are an inverter output current command value of 100% and an inverter input power of 4.4 kW.

In FIG. 3, the specified value of the inverter output current command value is set to 66% from the input power characteristic of the inverter with respect to the output current command value of the inverter, and the specified value of the inverter input power is the inverter input with respect to the inverter output current command value of 66%. The power characteristic is set to 0.7 kW which is about 35% with respect to 2.0 kW.
If the specifications of the ozone generator change due to an increase / decrease in the amount of ozone generated or an increase / decrease in the glass tube, the inverter's input power characteristics with respect to the inverter's output current command value are obtained each time, and the inverter output current command value is specified. Value and specified value of inverter input power.

For example, when operating in the rated ozone generation state (inverter output current command value 100%, inverter input power 4.4 kW), if the glass tube constituting the ozone generator 1 is broken, the ozone generator is short-circuited. Silent discharge becomes impossible and ozone generation stops. In the short circuit state, since the ozone generator does not consume active power, power to the ozone generator 1 cannot be input, so that the input power of the inverter 2 is reduced from a specified value.
Here, the inverter 2 uses the constant output current control method as in the conventional case. That is, the output current of the inverter 2 is controlled so as to be constant regardless of the state of the ozone generator 1.

In this case, since the inverter output current command value is 100% with respect to the specified value 66% of the inverter output current command value, the output of the current comparator 4a is turned on. Since the inverter input power is reduced to 0.2 kW or less with respect to the inverter input power specified value of 0.7 kW, the output of the power comparator 4b is turned on. As a result, the outputs of the current comparator 4a and the power comparator 4b of the control device 4 are both turned ON, and an ozone generator abnormality signal is sent to the outside.
In the above embodiment, the specified value of the inverter output current command value is set to 66% and the specified value of the inverter input power is set to 0.7 kW. However, the glass tube of the ozone generator 1 is short-circuited and is clearly abnormal. If the predetermined value is such that it can be discriminated, the designer can determine another value for the specified value.

In an ozone generator according to an embodiment of the present invention, an ozone generator that generates ozone by silent discharge by applying an electric signal from an inverter for converting into an electric signal having a desired frequency, and the inverter. If the inverter output current command value is higher than the specified value and the inverter input power is lower than the specified value, an ozone generator abnormality signal is output. It can have a mechanism to do.
Since the output current converter of the inverter is unnecessary, the cost can be reduced and the circuit is simplified and the reliability of the apparatus is greatly improved. Furthermore, there is no need to adjust the current converter, and the test time of the ozone generator is greatly reduced.

According to the first embodiment of the present invention, a direct current input is received from a commercial power supply via a power conversion means including a power converter 5 as a forward conversion device, and converted into an alternating current output having a desired frequency. An inverter 2 as an inverse conversion device, a current command means comprising a current indicator 6 for giving a predetermined current command value to the inverter 2 and controlling the output current of the inverter 2 to a constant value, and an application from the inverter 2 in the ozone generating apparatus having the ozone generator 1 for generating ozone by the AC electrical output which is, compared with the specified value I ₀ of the current command to the current command value I _d of the current command means comprising said current indicator 6 a current comparator means comprising a current comparator 4a for deriving a first signal output when 2 output current command value I _d of the aforementioned inverter is prescribed value I ₀ or more states, the power Compares the input power P _d and the input power of the prescribed value P ₀ of the detected the inverter 2 by the power converter output detector 5a for detecting the output of the power conversion means including a converter 5 input power of the inverter 2 a power comparator means consisting of a power comparator 4b for deriving a second signal output when in the state of P _d is lower than the prescribed value P _0, the first signal by the current comparator means comprising the current comparator 4a A logic operation unit comprising an AND circuit 4c for deriving a logical operation output by performing a logical operation on the output and the second signal output by the power comparison unit comprising the power comparator 4b, and comprising a logic operation comprising the AND circuit 4c. Since the abnormality signal output means comprising the control device 4 for outputting the abnormality signal related to the ozone generator 2 by the logical operation output by the operation means is provided, an output current converter of the inverter is provided. In addition, it is possible to obtain an ozone generator that can detect an abnormality of the ozone generator with a simple configuration that improves reliability.

It is a block diagram which shows the structure of the ozone generator in embodiment by this invention. It is an ozone generation | occurrence | production principle figure in the ozone generator in embodiment by this invention. Characteristic diagram showing the same input power characteristic with respect to the output current command value of the inverter, the specified value of the inverter output current command value, and the specified value of the same input power in the ozone generator with an ozone generation amount of 250 g / h in the embodiment according to the present invention. It is.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ozone generator, 1a Capacitor by dielectric, 1b Capacitor by discharge space, 1c, 1d Zener diode, 2 Inverter, 3 transformer, 4 Control device, 4a Power comparator, 4b Current comparator, 4c AND circuit, 5 Power conversion 5a Power converter output detector 6 Inverter output current indicator.

Claims (2)

  Ozone generation comprising an inverter with constant output current control for receiving a predetermined electric input and converting it into an electric output having a desired frequency, and an ozone generator for generating ozone by the electric output applied from the inverter In the device, when the output current command value of the inverter is equal to or greater than a specified value and the input power of the inverter is lower than the specified value, an abnormal signal output that outputs an abnormal signal related to the ozone generator An ozone generator characterized by comprising means. An inverter for receiving a DC electric input from a commercial power source through a power conversion means and converting it into an AC electric output having a desired frequency, and giving a predetermined current command value to the inverter and setting the output current of the inverter to a constant value In an ozone generator comprising: current command means for controlling; and an ozone generator that generates ozone by the AC electric output applied from the inverter, the current command value of the current command means is a specified value of the current command. And comparing the input power of the inverter with a specified value of the input power, comparing the input current of the inverter with a current comparing means for deriving a first signal output when the output current command value of the inverter is equal to or greater than a specified value. A power comparing means for deriving a second signal output when the input power is lower than a specified value; and a first signal output by the current comparing means. Said logical operation and a second signal output by the power comparing unit, the output current command value of the inverter is equal to or greater than a prescribed value, and, in a state where the input power of the inverter is lower than the specified value An ozone generator comprising: an abnormality signal output means for outputting an abnormality signal related to the ozone generator by a logic operation output from the logic operation means.

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