Application of Magnetic Governor in Energy Saving of Fan in cement PlantDate: 2019-06-25 Views:
Cement industry is an indispensable basic raw material industry for national economic development, production and construction and people's life. With the development of China's economy, the cement industry has reached a considerable scale. With the rapid development and application of new dry cement production technology. The process system needs a large number of fan equipment, including raw material grinding circulation fan (roller milling, ball milling), waste gas treatment exhaust fan, kiln tail high temperature fan, grate cooler cooling fan, cooler exhaust fan, coal grinding system fan, cement grinding roller press system circulation fan, cement grinding ventilation fan and powder selection fan. These fans need to follow the working conditions. Variations in conditions and production, adjustment of air volume, wind pressure. The electric power consumption of these large fan motors accounts for 30%of the cost. The competition among cement production enterprises is very fierce. The most critical is to compress the manufacturing cost. Therefore, it is important to choose a reasonable speed regulation mode to meet the production under different working conditions, and reduce the electric energy consumed by the system fan, which will play an important role in reducing the cement cost and improving the economic benefits of the enterprise. The magnetic governor introduced in this paper is a good way to solve these problems.
First, the present situation of fan energy consumption in cement plant
The selection points of fans in cement plant are designed according to the full load state. The actual production is affected by many complex factors and deviates greatly from the working state of the design. The fan often runs under the full load condition below the design. In order to meet the full load state, the fan adds a certain amount of air volume and wind pressure reserve when selecting the type. If the air volume reserve is 10% and the wind pressure reserve is 15%, then the power reserve is 26.5%, which artificially increases the power reserve of the motor. The fan with bag dust collector is used in the system. The difference between the new bag and the filter bag resistance before changing the bag is about 1 × 3, which is equivalent to 400 × 500Pa, and the fan design is selected. It is considered according to the maximum resistance of the filter bag, so for a long time from the beginning of production, the fan often runs under low resistance, which is obvious in the production process and has an effect on the fan power by about 20%. The opening and stopping of raw material grinding and coal grinding have influence on the air volume of kiln head and dust collector at the end of the kiln, especially in recent years, the opening and stopping of waste heat power generation system will have an impact on the air volume and wind pressure of the system fan. Affected by the above factors. It is necessary for cement plants to choose an effective method to adjust performance to meet the inevitable requirements of the process.
Second, the traditional performance adjustment mode of fan in cement plant at present.
Regulating door throttling method is the most commonly used traditional regulation method in cement plant at present. The air volume of fan is adjusted by adjusting the opening of fan inlet valve. However, this method has some shortcomings, such as artificially increasing wind resistance, low fan efficiency, serious loss and so on. With the change of inlet valve opening, the working point of fan system is offset and the efficiency is reduced.
The speed regulation of the fluid coupling is to change the rotating speed of the torque and the output shaft transmitted by the fluid coupling by changing the height of the liquid level in the working chamber of the hydraulic coupler when the rotation speed of the motor is not changed, so that the rotation speed of the motor and the fan is not consistent, and the purpose of adjusting the air volume is realized. But the power and the mechanical loss are to be generated in the adjusting process, the rotating speed of the output end of the motor is not changed, the required power is not changed, and the energy saving can not be realized only by the purpose of speed regulation.
The variable frequency speed regulation of the motor is to achieve the purpose of speed regulation by changing the frequency and the rotation speed of the power supply, and the variable frequency speed regulation of the motor can realize the stepless speed change of the speed of the fan, and the flow rate of the fan can be adjusted. The method can not only speed the speed, but also has the energy-saving effect, and the current application is wide. The foreign products of the frequency converter are more stable, but the price is high. The quality of the frequency converter is uneven, and the electric components of the frequency converter are more, in particular, the processing chip is upgraded quickly and the aging is easy to occur. Spare parts are required, and professional maintenance personnel shall be required for troubleshooting. Therefore, the life of the frequency converter is generally 5-10 years. The frequency converter is high in price and large in volume. For operating environment, High, especially for medium high-voltage frequency converter, need a special air-conditioning room. The use of a frequency converter usually requires the use of a dedicated variable-frequency motor.
III. Principle of the magnetic governor with the most energy-saving advantages
Magnetic speed regulation technology is a new and new technology which was born and developed in the early 21st century. The principle is to follow the basic law of magnetic induction, i.e. ``Lun law'' . When the driving force drives the rotation of the conductor disk, the cutting magnetic line moves with the permanent disk installed at the load end, and then the eddy current is generated in the conductor disk. The vortex generates the anti-magnetic field around the conductor disk, so as to drive the permanent disk to rotate and realize the air transmission of energy. The magnetic speed regulation is based on these laws, and is developed by combining the application of rare earth permanent magnet technology, new transmission technology and high-precision equipment manufacturing technology.
IV. Technical advantages of using magnetic speed-regulating fan
Magnetic governor is a new mechanical energy saving speed regulation device, which is applied to centrifugal fan speed regulation and energy saving transformation in cement plant. It will be a great leap in energy saving and consumption reduction in cement plant. Its main advantages are as follows:
The main results are as follows: (1) High efficiency and energy saving: the stepless speed regulation of motor in the range of 0% and 98% can be realized by using magnetic speed regulating fan. The performance change of the fan follows the similarity determination: Q 1 ≤ Q 2 = (n1/n2), H 1 ≤ H 2 = (n1/n2) 2, T 1 T 2 = (n1/n2) 2, the output torque of P T motor is equal to the load torque, P 1 / P 2 = (n1/n2) 3 saves power by the speed regulation of the equipment, and the general power saving rate can reach 10% ≤ 60%. For example, when the speed is reduced to 80%, the flow rate is reduced to 80%, while the shaft power is reduced to (80%) 3 of the rated power. = 51.2%, so that the energy-saving effect of the flow is remarkable by changing the rotating speed, and the general energy-saving rate is more than 20%.
(2) The method is simple and reliable, the maintenance is small, and the land occupation is small. The performance is reliable, the service life is long, and the maintenance is basically maintenance-free. The design life is 25-30 years. The device has the advantages of simple structure and low failure rate of the electronic equipment, and only needs to change the relative position of the motor and the load when the equipment is installed, and the original coupling can be replaced by the magnetic speed regulator, and the laser calibration shaft is not required to be installed at the time of installation, and the centering error within 1 mm is not allowed, and an additional load is not generated. And the motor dragging system capable of adapting to the axial displacement of up to 10 mm can be used.
(3) Vibration isolation. The vibration amplification transmission of rigid coupling is reduced. The magnetic governor replaces the original rigid coupling, so that there is no mechanical connection between the motor and the load, and the vibration of the fan and the side vibration of the motor will not be transmitted to each other. At the same time, it also eliminates the amplification effect of vibration in the process of transmission, and will not produce vibration.
(4) Magnetic governor is a pure mechanical product, the performance is stable and does not need electricity, and can adapt to all kinds of bad working conditions: load slip speed regulation technology is adopted. The voltage of power grid does not affect the reliability of the original system. For the power grid voltage fluctuation, high harmonic content, flammable, explosive, wet, high dust content, high temperature, low temperature and other places, will not produce any pollutants to the environment.
(5) the total cost is the lowest, the magnetic speed regulation energy saving fan with magnetic coupling and governor is installed, the energy saving is obvious, the investment recovery is fast, the product structure is simple, there are no vulnerable parts, no electrical components are worn out, and the maintenance cost of the equipment is reduced. Non-contact transmission, simple control process, easy to achieve stepless speed regulation. The service life is 25 years, which is equivalent to the service life of 6 inverters.
(5)Magnetic governor is equipped with magnetic speed governor with wide application range of magnetic speed regulation and energy saving fan, applicable speed range:750~3000r/min, power:4.0~3000KW, torque:40~24650N.m, speed regulation:0~99%, efficiency:96-99%, slip difference:1~4%, installation accuracy:<3mm.
Since the application of the magnetic speed regulation technology, from the regulation of the throttle method, the hydraulic coupling technology, the electric variable frequency drive technology to the magnetic transmission technology, it is an epoch-making innovative technology in the power transmission history, and the revolution of the rotary mechanical power transmission technology is realized, In particular, the magnetic transmission technology is a green product which can achieve the double indexes of safety, reliability and energy saving and consumption reduction, and is an ideal substitute green product. The National Development and Reform Commission of the People's Republic of China, the Ministry of Industry and Information of the People's Republic of China, and the Ministry of Industry and Information of the People's Republic of China, shall not send a document, and focus on the promotion of the magnetic