KR20150031533A - Dgital control ozone generatoer - Google Patents

Abstract

A conventional analog control ozonizer has a problem that discharge current according to discharge resistance of discharge luminous caused by temperature change or accumulation of foreign materials is varied, thereby occurring over discharge or under discharge and not being able to automatically control optimum discharge current. In order to solve the above problem, a digital control ozonizer is disclosed which comprises a micom controlling electric current, which is digitally provided to the ozonizer, to make constant current flow in the ozonizer by detecting incoming current of the ozonizer. The ozonizer comprises discharge tubes and a power supply device as shown in the figure 1. The power supply device comprises an inverter which generates high frequency pulse; and a high voltage transformer for silent discharge.

Description

[0001] DIGITAL CONTROL OZONE GENERATOR [0002]

Disclosure of the Invention Problems to be Solved by the Invention The present invention relates to a problem that the discharge current due to the discharge resistance of the discharge tube due to the temperature change or the foreign matter accumulation phenomenon of the conventional analog control type ozone generator is varied and the optimum discharge current can not be controlled automatically due to excessive discharge or underdischarge The present invention relates to an ozone generator that is solved through microcomputer control.

Ozone (O ₃ ), which has a strong oxidizing power and is finally decomposed by autoxidation and reduced to oxygen, generates ozone (O ₃ , O ₃ ) which does not cause harmful secondary pollution and generates gas discharge to sterilize, deodorize, deplete, purify, , Water and wastewater treatment, and medical fields.

Ozone is a molecule bound with three oxygen (O) atoms and having a molecular weight of 48, a melting point of 251.5 ° C, and a specific gravity of 1.7. The coupling angle is 116.8 degrees and the O-O bonding distance is 1278 Å. In the underwater dissolution state, four resonance structures are characterized by a light blue color in liquid state, a black blue color in liquid state, and a dark color in solid state. There are various methods for generating ozone. Typical methods include ultraviolet, electrolytic, and high-pressure silent discharge type. High efficiency and economical method for industrial use are high pressure silent discharge type. The amount of ozone generated is controlled by varying the power density depending on the voltage and the frequency, and a method of applying a high voltage (14 [kV] or more) with a commercial frequency (50/60 [Hz]) and a medium frequency (Less than or equal to 10 [kV]) of the number (500 [Hz] or more).

Ozone generator generating ozone using gas discharge was first developed by Werner Von Siemens of Germany in 1857 as a silent discharge type ozone generator, and has been widely used as a practical ozone generator until now.

However, in practical silent discharge type ozone generators, when the raw material gas is oxygen and air, the ozone production yields are about 220 and 90 [g / kWh], respectively, so that the theoretical ozone production yield using 1,200 [g / kWh] It is necessary to improve the ozone production yield.

Therefore, in order to improve ozone generation yield in the US and Japan and other developed countries, it is necessary to use a silent discharge type ozone generator using a mixed raw material gas, a complex discharge type ozone generator in which silent discharge and surface discharge are superimposed, Ozone generators are being studied. Particularly, studies on factors affecting the discharge type such as the electrode shape material of the ozone generator, the distance between the electrodes, and the characteristics of the applied voltage are considered to be important for improving the performance of the ozone generator.

The ozone generator is composed of a discharge tube and a power supply as shown in FIG. 1. The power supply includes an inverter for generating a high-frequency pulse and a high-voltage generating transformer for silent discharge.

The biggest problem with existing ozone generators is that discharge current is changed due to discharging resistance due to foreign matter in the air to a discharge tube to which ozone is supplied. Therefore, there is a problem that the conventional power supply control device can not be controlled by analog method. This results in shortening the lifetime of the discharge tube and the breakage of the discharge tube and the dielectric, which ultimately leads to breakage of the power supply. Normally, ozone generators should have a lifetime of about 3 years. However, when used in actual field, most of the time, after 1 year, these problems cause A / S, shortening product life and adversely affecting profit structure of company have.

The second problem is that moisture inside the discharge tube is generated, which hinders silent discharge, and the amount of ozone generated is reduced due to overheating of the discharge tube. We used a heater or fan to solve this problem, but we found that it is analogue, which makes it difficult to control the temperature and humidity accurately.

Finally, the existing high voltage high frequency FBT (FlyBack Transformer) for neon sign needs to develop itself because the inventory is gradually getting short due to the decrease of neon sign demand.

In order to improve the performance of a conventional analog ozone discharge tube, an inverter for generating a high-frequency pulse is subjected to current control and overcurrent detection through digital control through a microcomputer. Also, ozone generator state information which is not present in the existing ozone generator is stored and displayed through the microcomputer.

Disclosure of Invention Technical Problem [8] The present invention can digitally control the variability of discharge current due to the discharge resistance of a discharge tube of a conventional analog ozone generator using a microcomputer, thereby reducing breakdown failure of a discharge tube and failure of ozone generation.

Plane discharge tube ozone generator Power supply block diagram for ozone generator Power supply circuit diagram for ozone generator Square wave output frequency adjustment algorithm Algorithm for judging normal operation Half-bridge circuit operation Method for reducing air impurities (CAD drawing)

The ozone generator can be divided into a discharge tube and a power supply unit. The discharge tube refers to the portion of ozone generated by the electric energy supplied through the power supply. An important part of this ozone generation is in the control of the power supply. FIG. 2 is a block diagram for digitally controlling power supplied to the ozone generator based on a micom.

A circuit diagram based on the block diagram of FIG. 2 is shown in FIG. The structure of the circuit can be divided into the following parts.

○ Input AC220V power source

○ Noise filter and DC rectifier circuit (Line filter & rectifier circuit)

○ HALF BRIDGE circuit for generating high voltage (half bridge switching circuit)

○ High Voltage Transformer (High Voltage Transformer)

○ FET drive circuit

○ MICOM circuit for frequency oscillation and control (microcomputer circuit)

○ Flyback SMPS circuit for MICOM power supply (switching power circuit 5V / 12V power supply)

The approximate operation method of FIG. 3 is as follows.

① C1 and LF1 are input noise filters, and BD1 and C3 are rectifier circuits that convert AC to DC.

② DC voltage rectified by BD2 and C4 has AC characteristic when U1 2B265 PWM IC is switched and applied to the primary side of transformer T1 and the voltage is induced on the secondary side and the induced voltage is converted to DC voltage by D5 and C13 And is rectified. The rectified DC voltage becomes a constant voltage source of 5 [V] through the U3 MC7805 and serves to supply power to the MICOM drive power terminal. Also, 12 [V] of CN3 corresponds to a spare power source for driving the fan which can be operated for the purpose of maintaining the temperature of the ozone generator.

③ When power is supplied to the MICOM circuit, square wave of frequency 18.5 [kHz] is output to Out1 and Out2. When the FET drive transformer drives the FET, the half bridge circuit operates and a high voltage is generated, discharging the ozone generator, causing current to flow and detecting the input current as CS1. In this process, the input current uses a current transformer (CT). In general, the input current can be obtained through the characteristic that the secondary current flows 5 [A] when the rated current flows to the primary side.

④ If the detection voltage converted by CS1 is applied to the MICOM C / S (current sensor) stage and the MICOM is higher than 2.5 [V] compared with the programmed reference voltage 2.5 [V] read at 3 [s [ the input voltage of AC220V is set to 2 [A] by keeping the voltage input to the C / S stage at 2.5 [V] by decreasing the frequency by 0.25 [kHz] The algorithm is used to make it flow. (Figure 4)

⑤ If the input current of AC220V is higher than 2.6 [A] or lower than 1.2 [A] due to a problem of ozonizer load, the voltage should be 2.8 [V] or higher at the MICOM S / D (shut- Or 1.5 [V] or less, and MICOM is programmed to stop operation and restart after 20 minutes. If this stop operation is repeated 20 times, MICOM stops operation until it is reset manually. (Fig. 5)

Out1 and Out2, whose frequency is adjusted based on the voltage of C / S stage, are connected to a transformer for high frequency / high voltage output via FET drive circuit and half bridge circuit. Here, the operation of the half bridge circuit is shown in Fig.

로 고정하였다. 구형파의 출력 주파수에 따라 1주기의 시간은 다음과 같이 결정된다.As shown in FIG. 6, there is no section in which two square wave outputs operate simultaneously. This section is called the dead zone

Respectively. The time of one cycle is determined as follows according to the output frequency of the square wave.

이면 주기는

이고

로 고정되어 있으므로

의 값을 갖는다. 이러한 구형파에 대해 전체 주기에 대해 high value가 차지하는 시간의 비율을 duty cycle이라 하고 다음과 같이 정의된다.For example, if the frequency of the square wave output from MICOM is

If the cycle is

ego

Is fixed to

Lt; / RTI > The duty cycle is defined as the ratio of the time that the high value takes over the whole cycle for this square wave.

이면 46.4[%]의 duty cycle을 갖고, 구형파의 주파수가

이면 46.6[%]의 duty cycle로 커진다.That is, when the dead zone time is fixed, the duty cycle becomes smaller as the frequency of the output waveform increases. For example, if the frequency of a square wave is

Has a duty cycle of 46.4 [%], and the frequency of the square wave is

, The duty cycle becomes 46.6 [%].

The concentration of ozone to be generated may vary depending on the application in which the ozone generator is intended to be used. This is related to the target input current. The devices that can control this are the variable resistors corresponding to VR1 and VR2 of the circuit diagram. The principle of adjusting the ozone discharge current using the above-described output frequency adjustment algorithm can be described as follows.

○ Principle of reducing ozone discharge current

- Turn the VR1 variable resistor to the left.

- The voltage at the C / S stage of the microcomputer increases due to the voltage drop of the resistor R14, VR1, R15.

- Since the voltage applied to the C / S stage of the microcomputer is higher than the reference voltage of 2.5 [V]

- The oscillation frequency increases by 0.25 [kHz].

- The switching frequency of the half bridge increases.

- The secondary voltage of the high-voltage transformer is lowered.

- Ozone discharge current is low.

- The input current is low.

- CT detection voltage is lowered.

- The charging voltage of C15 capacitor is low.

- The voltage at the C / S stage of the microcomputer is lowered due to the voltage drop of the resistor R14, VR1, R15.

- The input current is lowered by repeating operation until the voltage applied to the C / S terminal of the microcomputer becomes equal to the reference voltage 2.5 [V].

○ Principle of increasing ozone discharge current

- Turn the VR2 variable resistor to the right.

- The voltage at the C / S stage of the microcomputer is lowered due to the voltage drop of the resistor R14, VR1, R15.

- Since the voltage applied to the C / S terminal of the microcomputer is lower than the reference voltage of 2.5 [V]

- The oscillation frequency is lowered by 0.25 [kHz].

- The switching frequency of the half bridge is low.

- The secondary side voltage of the high-voltage transformer becomes high.

- Ozone discharge current increases.

- Input current increases.

- The CT detection voltage becomes high.

- The charging voltage of capacitor C15 is increased.

- The voltage at the C / S stage of the microcomputer increases due to the voltage drop of the resistor R14, VR1, R15.

- The input current is increased by repeating operation until the voltage applied to the C / S terminal of the microcomputer becomes equal to the reference voltage 2.5 [V].

○ Variable resistance operation method

- Correct the deviation of CT detection voltage by VR2 variable resistor due to variation of parts such as trans-poker, ozone generator load, CT, resistance, etc.

- When the variable position of VR1 variable resistor is in the center and the variable position of VR2 variable resistor is turned to the left end and 220 [V] is turned on, the current flows below 2 [A]

- At this time, slowly turn the VR2 variable resistor to the right to adjust the current of 2A. - After correcting with VR2 variable resistor, adjust the input current to about 1.5 ~ 2.5 [A] with VR1 variable resistor

.

The power supply of the ozonizer capable of digital control using the microcomputer should select the winding ratio of the high-voltage transformer correctly according to the shape of the discharge tube. The reason for this is that the planar and cylindrical discharge tubes have different capacities. This affects the impedance seen from the primary side of the high-voltage transformer, so that the optimum frequency varies. In addition, the winding ratio of the transformer can also be an important parameter since it can substantially affect the load impedance.

The present invention uses two types of discharge tubes. The two discharge tubes are not only different in shape but also in their characteristics. That is, since the load varies, a power supply suitable for each discharge tube should be constructed. The parameters that can be determined from the power supply are the winding ratio and the diameter of the high voltage / high frequency transformer (FBT). Also, several discharge tubes can be used for the cylindrical discharge tube ozone generator.

In order to generate ozone of high yield, the state of air as a raw material of ozone is important. With this adventure, some companies' ozone generators use oxygen rather than normal air. The use of oxygen instead of normal air improves yield, but it is a disadvantage in terms of economy, so a careful approach is needed. The content of impurities can be minimized by using a filter and a heater as shown in Fig. 7 in order to use ordinary air as a raw material of ozone and reduce the content of impurities.

Air, which is the raw material of ozone, is filtered through the filter to filter out primary impurities and pass through the motor fan through the heater to reduce the humidity and become an input to the ozone generator. It is known that the removal of impurities and the drying process can greatly improve the yield of ozone.

A device for allowing the air containing an appropriate humidity to flow into the circular discharge tube by using an air cooler (air chiller) may be used.

As a result of the present invention, it is possible to digitally control the variability of the discharge current due to the discharge resistance of the discharge tube of the conventional analog ozone generator, thereby reducing the breakdown failure of the discharge tube, It was.

Claims (5)

An ozone generator for measuring a current flowing through a discharge tube by a digital circuit and controlling the power supplied to the discharge tube by a digital circuit so as to flow a constant current to a discharge tube for generating ozone,
The digital circuit uses a microcomputer,
The power supplied from the power supply unit is supplied to the microcomputer through the noise filter and the rectifying circuit, the rectified DC voltage through the transformer,
When the micom is supplied with power, two square waves are output. The two square wave outputs are connected to the transformer through the FET drive circuit and the half bridge circuit. The high frequency, high voltage transformer output is connected to the ozone generator, And a microcomputer operative to detect an input current of the ozone generator and to control a current supplied to the ozonizer in a digital manner so that a constant current flows through the ozone generator. The method according to claim 1,
The input current detected by the ozone generator is converted into a detection voltage and applied to the microcomputer. The voltage is increased when the reference voltage is higher than the reference voltage and lower than the reference voltage when the voltage is read at a predetermined time interval. The microcomputer is operated so as to maintain the reference voltage so that the current supplied to the ozone generator flows at a constant magnitude. The method of claim 2,
The frequency of the output of the two square wave type microcomputers in which there is no section to be operated at the same time is adjusted based on the detection voltage. The dead zone time, which is a section that is not operated simultaneously, is fixed, The duty cycle, which means the ratio of the high value to the whole period, is reduced with respect to the square wave, and the duty cycle becomes larger as the frequency of the output signal of the microcomputer becomes smaller. The method of claim 3,
The concentration of ozone to be generated is adjustable using a variable resistor. The method of claim 4,
When the ozone discharge current is reduced by adjusting the variable resistance, the detection voltage of the microcomputer is increased, and the voltage applied to the measurement voltage of the microcomputer is higher than the reference voltage, so that the oscillation frequency becomes higher, the switching frequency of the half bridge becomes higher, The voltage decreases and the ozone discharge current decreases. As a result, the input current is lowered and the detection voltage is lowered. However, when the detection voltage input to the microcomputer is repeatedly operated until the voltage becomes equal to the reference voltage, Operating,
When the ozone discharge current is increased by adjusting the variable resistor, the detection voltage of the microcomputer is lowered, the voltage applied to the microcomputer's measured voltage is lower than the reference voltage, so that the oscillation frequency is lowered and the switching frequency of the half bridge is lowered. The output voltage becomes higher and the ozone discharge current becomes higher. As a result, the input current becomes higher and the detection voltage becomes higher. However, the input current is increased by repeating operation until the detection voltage input to the microcomputer becomes equal to the reference voltage , Ozone generator.

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