Application of high frequency ozone generator

This article mainly describes the application of ct100 series frequency converter in high frequency ozone generator of Shenzhen Dolycon Technology Co., Ltd. the power supply system realized by ct100 frequency converter ensures the stability and reliability of ozone generator system.

Ozone is a strong oxidant, which is widely used in drinking water, sewage, industrial oxidation, food processing and preservation, pharmaceutical synthesis, space sterilization and other fields. Since ozone will fission into completely harmless oxygen atoms after acting on microorganisms, it will never produce secondary pollution. Therefore, ozone has been used more and more to replace the disinfection of chlorine and its compounds. Ozone has been recognized as the best disinfectant for environmental protection. The power frequency power supply is used in the traditional ozone generation scheme, but the power frequency generator is large in volume and high in power consumption, and has been basically withdrawn from the market. The medium and high frequency generators have the advantages of small size, low power consumption and large ozone production, which are the most commonly used products now. This paper introduces the application of ct100 series frequency converter developed by Shenzhen Dolycon Technology Co., Ltd. in high-frequency ozone generator, taking the inverter matching touch screen of a Beijing ozone generator company as an example.

Principle of high frequency ozone generator
Principle of ozone generation
The industrial production method of ozone usually uses the principle of high-voltage silent discharge: let the purified dry air or oxygen flow through the electrode gap. Through the high-voltage discharge gap, some oxygen molecules are broken and the chemical bond is broken to generate oxygen atoms. The oxygen atoms and oxygen molecules combine to form ozone. This method of ozone generation is called corona discharge, that is, when the high-frequency sinusoidal AC voltage between the two electrodes of the discharge device is greater than the critical corona inception voltage, corona discharge is generated on the surface of the discharge electrode.
The instability of ozone makes it difficult to realize bottled storage. Generally, ozone generator can only be used for on-site production, which requires that the output of ozone can be automatically adjusted according to actual needs, but the gas production efficiency should not be reduced.

System structure of high frequency ozone generator
The main structure of high frequency ozone generator is divided into four parts

1. Power supply part: the core control part is composed of high frequency output frequency converter and step-up transformer. The high-frequency output converter transforms the power frequency power supply into the high-frequency output above 8kHz, which has provided high-frequency power supply; The step-up transformer transforms the high-frequency power supply provided by the frequency converter into a high-frequency and high-voltage power supply of 2000 ~ 8000v by boosting the voltage.

2. Air source part: ozone generator can use two kinds of air sources, one is air provided by oil-free air compressor, dryer, etc. The other is pure oxygen or oxygen enriched air, which is provided by oxygen cylinder or oxygen generator. After entering the generator, the air or oxygen should be further dried and depressurized, and continuously enter the ozone generating part after metering.

3. Ozone generation and discharge chamber: vertical tubular unit gas chamber is adopted, which is composed of electrode tube, dielectric pipe or water pipe. Both ends of the discharge chamber are connected with stainless steel pipes for air flow passage, and aluminum heat sinks are pasted on the back of the two discharge plates of the discharge chamber for air cooling or water cooling. After entering the discharge chamber, oxygen or air is divided into two paths, which flow through the high-frequency and high-voltage electric field along the surface cracks of the discharge sheet. The chemical bond in some oxygen molecules is broken to generate oxygen atoms. The oxygen atoms combine with oxygen molecules to form ozone molecules, and the mixture of ozone and air is pumped out along the pipeline.

4. Cooling part: the working efficiency of the ozone generator determines that a considerable part of the electric energy is not used to generate ozone, but converted into heat. High temperature is conducive to the decomposition of ozone, resulting in the decrease of ozone production and concentration. Therefore, it is necessary to cool the ozone generator room. Axial flow fan is generally used for air cooling treatment.

Dolycon ozone generator frequency conversion solution
Control scheme
Ct100 frequency converter of Shenzhen Dolycon Technology Co., Ltd. takes DSP control system as the platform, adopts domestic leading PG free vector control technology, and cooperates with various protection methods. It can be applied to asynchronous motor and provides excellent driving performance. Products in the air duct design, hardware configuration, software functions are greatly improved customer usability and environmental adaptability.
Combined with the technology of ozone generator and the powerful VF separation control performance of ct100 series inverter, the maximum output frequency can reach 8kHz, and the output voltage and frequency can be adjusted independently. The system can switch between voltage locking mode and current locking mode freely. In the voltage locking mode, the resonance point of the system is automatically searched to ensure the best operation efficiency of the system; Under current locking mode, the load output can be determined freely, and the optimized PID regulation mode ensures fast and stable load locking without overshoot.
The implementation block diagram of ct100 series inverter on high frequency ozone generator is as follows:

Specific working conditions

System debugging steps
Step 1: inverter parameter configuration: check the wiring, set f01.00 ~ f01.03 parameters according to the load power, and then set the inverter parameters according to the frequency converter parameter setting table. The parameter setting table of frequency converter is as follows:

Step 2: resonance frequency point search: after entering the touch screen interface, the touch screen automatically matches the maximum set value of voltage and current according to the set rated voltage / current and other parameters. At this time, the parameter setting is locked.

Click login and enter the login password to enter the pending operation state. In the state of voltage locking, configure the setting voltage according to the actual situation, and roughly set a set frequency, and then run the equipment. The device automatically adjusts the output frequency under the set voltage and continuously records the contrast output power. Set the operating frequency of the maximum output power under the output voltage as the resonance frequency corresponding to the current voltage. The set frequency is automatically updated to the found resonant frequency.

Please stop the machine manually after the resonance frequency point search is completed.

Step 3: current locking mode operation: after the system stops, switch the operation mode to the current locking mode. At this time, the setting current is configured according to the actual working conditions. The inverter operates in VF separation mode, and automatically adjusts the output voltage through PID control when the output frequency is locked to ensure the stability of the output current, that is, the gas production is basically constant.
According to the actual operation condition, the error between the output current and the set current is compared in real time. If the output current oscillates, the proportional coefficient and integral coefficient can be adjusted manually to ensure the fast and stable current regulation without overshoot.
With the deepening of people's understanding of environmental protection, ozone generator will become more and more common. Dolycon ct100 series frequency converter combines the functions of high frequency power output, VF separation control, resonance point automatic locking, load closed-loop output and other functions, which perfectly completes the efficient balance between the occurrence and use of ozone. Under the premise of meeting the process requirements of customers, it greatly improves the operation efficiency of the system, and has been unanimously praised by customers!