⑧ Numerous project renovation experience, mature and stable implementation team, zero safety accident process management ability, and casting high-quality renovation results.

2. Causes and hazards of SVG dust and moisture entry issues

① Causes of dust entry:

The filter material cannot prevent dust under strong wind pressure

Analysis of the pressure borne by the SVG inlet air filter material:

The area of the SVG air inlet window is usually around 1 square meter, and the pressure generated by the centrifugal fan configured for SVG during operation is usually ≥ 500Pa. Therefore, the concentrated suction force on the 1 square meter air inlet window filter material is ≥ 500N, which is equivalent to the suction force of 50Kg object gravity. Therefore, the key to the effectiveness of dust prevention is that the filter material does not deform at both macro and micro levels under the suction force generated by high wind pressure.

SVG, inverters (inverters), and various forced air cooled electrical equipment are equipped with centrifugal or axial fans, which generate high air pressure and large air volume during operation. Conventional IP5X ventilation and dust filtration devices cannot prevent dust from entering, which is the main reason for dust entry.

Figure 2.1 Severe accumulation of dust inside SVG

● Does not meet dust prevention standards:

The protection level against solid foreign objects represented by the first characteristic number in Table 2

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Figure 2.2 Meaning of Protection Level Standards

Standard: GB4208-2017 shell protection level (see Figure 2.2), IP5X (i.e. dustproof level 5) cannot prevent dust from entering. Therefore, using IP5X ventilation and filtering devices cannot prevent dust from entering. According to this standard, under forced air cooling conditions and dust proof level requirements, a standard that meets the dust density IP6X (i.e. dustproof level 6) should be used.

The ventilation and dust filtering device lacks self-cleaning function, which leads to dust entry, increasing labor and reducing power generation

● Avoid the generation of negative pressure:

Negative pressure is caused by the blockage of the SVG inlet window filter material, which is generated under the strong wind pressure of the centrifugal fan equipped with SVG. The solution is to use intelligent automatic control to self clean the filter material and maintain good ventilation and no blockage for a long time.

② Causes and solutions of dampness

● Liquid water (i.e. rainwater) entering:

In rainy and snowy weather, rain and snow are pumped into containers under wind pressure.

Figure 2.3 Rainwater being pumped into the SVG interior

● Gaseous water (water vapor) entering:

In rainy, snowy, and foggy weather, the air humidity is almost 100%. Electrical equipment such as SVG is forced to cool and dissipate heat, and gaseous water vapor is pumped into the SVG device with the air. Therefore, SVG is prone to various faults caused by moisture condensation.

Gaseous water is a component in the air, with a molecular weight (18) smaller than the average molecular weight of air (29). Where air can enter, gaseous water vapor is more likely to enter.

● Temperature difference changes, resulting in moist condensation

When the inverter is running, the temperature inside it and the container is high. When in standby mode, the heat generation is small, and the temperature drops rapidly. Due to rapid temperature difference changes, moisture condensation is easily generated.

3. SVG's intelligent dust tight ventilation, dehumidification, and self-cleaning system solution

(7-step renovation plan) Nesprot Company adopts the SVG cloud intelligent dust dense ventilation, dehumidification and self-cleaning system solution to solve the problems of SVG ventilation, heat dissipation, dust prevention, and dehumidification and moisture-proof. At the same time, it can also perform independent frequency conversion and speed regulation renovation on each channel of the original centrifugal fan.

① Detection and Control

Real time detection of temperature, humidity, and dust concentration in the SVG room, and automatic control of ventilation, dust prevention, dust removal, and dehumidification based on parameters, forming a closed-loop control of the internal microenvironment of SVG

Automatic control, manual remote control (environmental control to solve abnormal weather conditions)

② Ventilation, heat dissipation, and dust prevention plan

Adopting IP65 protection level air inlet window to ensure efficient ventilation and good dust prevention

Equipped with automatic filter material self-cleaning function to prevent dust from blocking the filter material

Reminder for cleaning the filter material

③ Scheme for preventing liquid water (rainwater) from entering

Equipped with an IP65 dustproof filter fan and window, the waterproof level has been increased to IPX5. This product can still prevent rainwater from entering even when the inlet wind speed is ≤ 4m/s.

Note: According to GB/T 4208-2017 "Degrees of Protection Provided by Enclosures (IP Code)", in order to prevent water from entering during outdoor heavy rain, the SVG air inlet window should meet the waterproof level IPX5 and pass the CNAS laboratory type test

Test method for waterproof grade IPX5: Each unit is equipped with a separate ventilation and dust filter device, spraying 12.5 liters of water per minute for 3 consecutive minutes without water entering.

④ Dehumidification and condensation prevention of gaseous water (steam)

We use thermal expansion to reduce relative humidity for dehumidification.

Due to the huge ventilation volume of SVG, real-time dehumidification of huge air volume is required. Industrial Dehumidifier consume too much energy and occupy more space, which affects the electrical safety distance in SVG.

There are two methods to reduce relative humidity by using thermal expansion: dehumidification at the inlet interface and dehumidification through SVG indoor dew point control.

Dehumidification at the air inlet interface:

During SVG operation, moisture is removed from the air inlet interface to dehumidify the humid air flow. After the air enters the room, the SVG generates heat during operation, and with the help of the heat generated during SVG operation, the humidity continues to decrease to 50-70%. This way, the gaseous water in the air will not cause harm to the SVG equipment.

The dehumidification of the air inlet interface can be applied to dehumidification during SVG operation and SVG shutdown. The system will automatically perform dehumidification based on real-time temperature and humidity conditions.

⑤ Frequency Conversion Transformation of SVG Original Centrifugal Fan

The intelligent ventilation and dust prevention system can detect the temperature of the SVG device where up to 32 centrifugal fans are located, and provide data to the system controller. The system controller can independently adjust the speed of each centrifugal fan through PID speed control based on the collected temperature of each SVG, to match the heat generation and heat dissipation capacity, and effectively dissipate heat.

⑥ Cloud/local closed-loop monitoring

Configure mobile monitoring programs and on-site control cabinets, as well as central control room monitoring boxes, to achieve cloud/local Trinity monitoring of SVG indoor environmental data. Remote manual operation can also be achieved, such as in snowy days, remote manual control of the external surface of the filter material to clear snow, or in case of abnormal humidity.

⑦ Targeted solutions

Each SVG room (container) has its own unique characteristics in terms of dust and moisture conditions. Our company has rich experience and is adept at making targeted solutions based on the characteristics and difficulties of SVG rooms.