Some applications of frequency converter
1, air conditioning load
Office buildings, shopping malls, and some supermarkets and factories all have central air-conditioning. During the summer months, electricity consumption is very high. In hot weather, the electricity consumption of air-conditioners in Beijing, Shanghai, and Shenzhen accounted for more than 40% of peak power. Therefore, using the frequency conversion device to drive the refrigeration pump, cold water pump, and fan of the air conditioning system is a very good energy-saving technology. At present, many companies specializing in air conditioning have emerged throughout the country. The main technology is frequency conversion and energy saving.
2, crusher load
Many crushers and ball mills are used in metallurgical mines and building materials, and the effects of such loads after frequency conversion are significant.
3, large furnace calcining furnace load
Most large industrial rotary kilns (converters) such as metallurgy, building materials, and caustic soda used DC, commutator motors, slip motors, cascade speed control, or medium-frequency unit speed control. Because these speed control methods have slip rings or low efficiency, in recent years, many units have adopted variable frequency control and have excellent results.
4, the compressor load
Compressors also belong to a wide range of applications. Low-pressure compressors are commonly used in various industrial sectors. High-pressure and large-capacity compressors are used in steel (such as oxygen generators), mines, chemical fertilizers, and ethylene. The use of variable frequency speed regulation brings the advantages of small starting current, energy saving, and optimized equipment service life.
5, rolling mill load
In the metallurgical industry, in the past, large-scale rolling mills mostly used AC-AC frequency converters. In recent years, AC-DC-AC frequency converters have been used. The exchange of rolling mills is a trend, especially in light-load mills, such as the multi-stand of Ningxia National Aluminum Products Factory. The aluminum rolling mill adopts a universal frequency converter to meet the requirements of low-frequency band start-up, synchronous operation between racks, constant tension control, and simple and reliable operation.
6, winch load
The hoisting machine load is frequency controlled, stable and reliable. Ironworks blast furnace hoisting equipment is the main raw material conveying equipment for ironmaking. It requires smooth starting and braking, uniform acceleration and deceleration, and high reliability. Many of the original use of cascade, DC or rotor resistance series speed regulation, low efficiency and poor reliability. Replace the above-mentioned speed control method with the AC frequency converter, can obtain the ideal result.
7, converter load
The converter load is simple and reliable, and the operation is stable.
8, roller class load
Roller class load, mostly in the iron and steel metallurgy industry, adopts AC motor frequency conversion control, which can improve equipment reliability and stability.
9, pump load
Pump load, a wide range of products, including pumps, oil pumps, chemical pumps, mud pumps, sand pumps, etc., there are low-pressure low-capacity pumps, high pressure and large capacity pumps.
Many water companies, such as water pumps, chemical and chemical industries, chemical pumps, reciprocating pumps, non-ferrous metals and other industries such as mud pump frequency control, have a very good results.
10, Crane, dump truck load
Cranes, dump trucks and other load torque are large and require stable, frequent and positive and require reliable. Frequency converter control cranes, dump trucks can meet these requirements.
11, drawing machine load
Wire drawing machines for wire production require high-speed, continuous production. The wire strength is 200Kg/mm2, the speed control system requires high precision, high stability and requires synchronization.
12, transport vehicle load
The use of frequency conversion technology in coal mine trucks or steel mills in steel plants works well. Fast start and stop, strong overload capacity, flexible forward and reverse, and coal leveling, correct weight (no more or less), basically do not need manual operation, improve raw coal production efficiency, and save energy.
13, elevator overhead tour car class load
Because the elevator is a manned tool, requiring a highly reliable drag system, but also frequent acceleration and deceleration and positive and negative, the elevator dynamic characteristics and reliability, while increasing the elevator ride safety, comfort and efficiency. In the past, the majority of elevator speed-regulating DCs were gradually converted to AC motor speed control in recent years, regardless of Japan or Germany. Many elevator factories in China are eager to use the frequency conversion to equip elevators. Such as Shanghai Mitsubishi, Guangzhou Hitachi, Qingdao Fujitsu, Tianjin Otis, etc. are using AC frequency control. Many of the elevators originally produced also undergo frequency conversion.
14, feeder load
In metallurgy, electric power, coal, chemical industry and other industries, there are many feeders. Regardless of disc feeders or vibrating feeders, the effect of frequency conversion is very significant. The disc feeder of sulfuric acid production line of Jilin Chemicals Dyestuffs Factory was originally used for slip speed control, low-frequency torque, failure, and frequent card transfer. After adopting variable frequency speed regulation, because it is an asynchronous machine, it has high reliability and power saving. What's more important is that the closed loop of the temperature transmitter guarantees the accuracy of the material to be transported. It will not cause the oxidizer to be transported excessively and overheated to cause an accident and ensure production. The orderliness.
15, heap reclaimer load
The stacker and reclaimer is the main equipment for the coal yard, dock, and mine material stacking. The main function is stacking and reclaiming. The automatic stacking and semi-automatic reclaiming are realized, the equipment reliability is improved, the equipment runs smoothly, no impact and shaking phenomenon, and the reclaiming process is rotated according to the 1/cosφ rule, which improves the revolving reclaiming efficiency of the bucket wheel and the belt transporting coal Evenness is very popular with workers.
16, fan load
Fan load is a large amount of equipment, steel, power plants, non-ferrous metals, mining, chemicals, textiles, chemical fiber, cement, paper and other industries more applications. Most of the use of adjusting the baffle opening to adjust the air volume, a lot of energy wasted, using frequency control, you can save electricity and reduce mechanical wear and prolong equipment life.
17, mixer load
There are many mixers in the chemical and pharmaceutical industries. The use of variable frequency speed control to replace other speed control methods has many advantages.
18, spinning machine load
Spinning process is complicated, many work stations require tension control, and some require position control. The frequency conversion speed regulation effect is good.
19, special power load
Many power supplies, such as experimental power supply and aircraft power supply (400Hz), can be completed with variable frequency devices. The advantages are low investment, quick results, small size, and simple operation.
20, paper machine load
Paper machines in China's papermaking industry require highly accurate SCR DC speed control methods, and some use slip motors and commutator motors. The reliability and accuracy are not high due to the presence of slip rings and carbon brushes. Leading to the backwardness of papermaking machinery, the general speed is only about 200m/min, which is difficult to compare with foreign 2000m/min. Therefore, the frequency conversion of papermaking machinery is a general trend.
21, washing equipment load
In the past, the washing machines and ironing facilities at larger hotels used mechanical speed control or pole-changing speed control. They could only provide one speed or several speeds, and were not ideal for fabrics that required repeated washing and ironing. Using frequency control, greatly improve the efficiency of the washing machine.
22, musical fountain load
It is a music fountain that attracts visitors. The level of the water is controlled by the frequency converter.
23, grinders and other mechanical loads
The spindle spindle does not require a high rotational speed and requires a high frequency of power supply, 200 Hz, 400 Hz or even 800 Hz. In the past, the power of the spindle motor was mostly dragged by the medium-frequency generator. IF units are bulky, inefficient, have many noises, and have poor accuracy.
24, cigarette machine load
The cigarette machines imported by the cigarette industry in the past, whether Molin 8 or Molin 0, are not stepless. Therefore, in the cigarette industry is mainly to solve the problem of stepless speed regulation and reliability, the technology is simple, the use of frequency converter is simple, and the effect is great.
25. Vibration reduction and noise reduction load
Many loads, such as large air compressors, medium frequency generators, etc., have large noise and vibration. With frequency conversion technology, vibration reduction and noise reduction can be achieved within the standard.
26, printing and dyeing machine load
Most printing and dyeing machines are multi-unit work equipment. The process requires each unit to run synchronously at the same linear speed and maintain a constant tension, otherwise it will break the cloth, wrapped cloth, uneven color, color is not enough, the shrinkage rate is too large and other quality problems. In the past, printing and dyeing machinery adopts a DC speed regulation system regardless of whether it is a common power supply method or a sub-power supply method.
Due to the inherent shortcomings of DC crazing, the printing and dyeing industry has gradually adopted AC inverter technology. The rotary screen printing machine is composed of a cloth feeding unit, a printing unit, a drying house guide belt unit and a cloth falling unit, and belongs to a complicated one of the printing and dyeing speed adjusting systems. Frequency control is used to form the speed chain control. Good synchronization performance, high precision and high reliability.
27, injection molding machine load
Injection molding machines are the key equipment for plastics processing and molding. In the past, most of the energy-saving methods used to convert electricity from △-type (triangular type) to Y-type (star-type) to save electricity, and the effect was general. The use of variable frequency speed control does not change the original structure of the injection molding machine and controls the pressure or flow of the oil pump in several processes (such as clamping, mold closing, injection molding, pressure keeping, mold release, mold retreat, etc.), saving 20% ​​to 52% %, better to replace the past, the proportion of valve throttle method, greatly reducing energy consumption, many injection molding plants in the Pearl River Delta have carried out frequency conversion. When remolding the injection molding machine, it is necessary to pay attention to mold acceleration, otherwise the output is reduced, pay attention to the harmonic interference at the input and output ends.
28. Wastewater treatment and other environmental protection loads
Environmental protection has become more and more important. It is related to the environment in which human beings are living. As a result, clean energy and green cities have emerged. Frequency control can be used in three aspects of environmental protection load. The first is industrial sewage treatment, the second is the waste power plant, and the third is the control of industrial smoke, exhaust, and dust removal.
29, glass, ceramics, pharmaceuticals, beverages, food, packaging and other production line load
Glass, ceramics, pharmaceuticals, beverages, food, packaging and other production lines using frequency control, have achieved very good results.
30. Offshore oil platform load
The use of AC motors for frequency conversion in oil drilling is much better than DC speed control, especially in areas with heavy sand and dust because of the reliability of AC motors. Offshore oil rigs require frequency converters.
31. Submersible pump load
Submersible pumping is a way of producing oil in the oil field. Submersible pumps are mostly operated in oil wells below 1800m. Most of them use full-frequency start-up, constant-speed operation, and have the following drawbacks:
Ø Excessive starting current will damage the motor insulation
Ø Produce impact torque, damage the structure of the pump;
Ø The pump suddenly generates a large suction force, which can easily inhale the sand and cause the pump to pump. There is no regulated system and large fluctuations in the liquid level in the downhole, resulting in unstable voltage and current, making the submersible motor over-excitation and under-excitation, causing failure.
32, polyester chip load
Polyester chips are one of the main products in the petrochemical industry. Due to the high precision of frequency control, it is easy to control multiple control points, and it is stable and reliable. After using variable frequency speed control, it can increase product quality and bring great benefits to enterprises. Many companies use variable frequency speed control technology when expanding capacity.