Significant effect of system power saving, combined with the actual operation of the enterprise, it is recommended that ceramic enterprises promote the application of a large number.

1 Frequency conversion control, power saving, application 1 Preface The ceramic industry is a large energy consumer, and the energy consumption cost accounts for about 1/3 of the total cost. Therefore, reducing energy consumption is a topic worth exploring for each enterprise. Among them, the application of frequency conversion control technology in the ceramic industry, especially the use of frequency conversion speed regulation of various fans to reduce power consumption, is recognized and accepted by more and more companies.

2 Fan characteristics and frequency conversion power saving principle Most of the fans in ceramic enterprises are driven by squirrel cage asynchronous motors, which are coaxially combined with the motors to form electromechanical integration products for constant speed operation. When it is necessary to adjust the air pressure and air volume, most of them use baffle valves to adjust, and the power loss is very large. Adjusting the air pressure and air volume of the fan when using variable frequency speed regulation is the best way to avoid power loss and save energy.

2.1 Fan parameters and characteristics Air volume Q, wind pressure H, shaft power P and efficiency Ti are the basic parameters of the fan. The air volume Q of the commonly used centrifugal fan is proportional to the speed n, the wind pressure H is proportional to the square of the speed n2, and the shaft power P is proportional to the cube of the speed n3. If the fan parameters and in a certain operating state are known, when the speed becomes n2, the corresponding parameter air volume (2, wind pressure H2 and shaft power P2 are respectively: let h be the ventilation resistance of the pipe network, i is the pipe The wind resistance of the network is known by the law of resistance h=rQ2. As shown in Figure (1), the fan characteristic curve, the intersection of the pipe network h=f(Q) curve and the fan H=f(Q) curve in the figure is called the operating point. The fan is in an operating state with an air volume of Qi and a wind pressure of Z. When the fan speed n and the wind resistance r of the pipe network change, the h=f(Q), H=f(Q) curves and their operating points all change accordingly. For example, A2 and A3A are the new working points, that is, the larger the Q, the larger the h, the smaller the characteristic curve of the H fan. Therefore, the basic principle and method of fan adjustment is to change the H=f(Q) of the fan itself (such as Change the speed n) or change the h=f(Q) of the external pipe network (eg change the wind resistance r).

2.2 The principle of variable speed and power saving The basic principle of variable frequency control is to directly change the power frequency of the AC power to a lower frequency AC power, to adjust the speed of the motor by changing the power supply frequency, and to meet certain torque requirements. It is known from electromechanics that the formulas for the speed and slip of asynchronous motors are: n=60f(ls)/P f stator frequency P stator pole pairs according to the above rate f, the speed n is proportional to f, so the power supply is changed The frequency can smoothly adjust the motor speed. One of the asynchronous motor speed regulation methods is to change the power frequency to change the motor rotor frequency, that is, frequency conversion speed regulation.

In the principle of energy saving, it is assumed that the fan works at the point of efficiency, and the output air volume is free. Its corresponding fan shaft power is proportional to the area AftOQi. If according to production requirements, the air volume needs to be changed from A to free. If the damper method is adopted, r3 increases to r4, h=f(Q) curve 3 becomes curve 4, and the operating point becomes A2. At this time, the fan power P2 is proportional to the area and does not decrease much compared to the dagger. If the motor frequency modulation is used to reduce A to f2, the H=f (Q) curve 1 of the fan becomes 2, and the operating point becomes A3. At this time, the fan power P3 is proportional to the area A3H3Q2. Obviously, compared with adjusting the damper, H3P3 is significantly reduced when the same air volume Q2 is satisfied. The electric power saved AP=P2-P3 is proportional to the area. It can be seen that this is a larger area.

Since Q is proportional to n and P is proportional to n3, when the air volume decreases, the frequency conversion speed regulation method is very effective in power saving. If Q needs to decrease by 50%, P will drop to (50%) M2.5%. 3Comparison of power consumption before and after the actual operation of the enterprise Jiangsu Yixing Jingtao Co., Ltd. has fully considered the cost reduction in each process of production work. Among them, the fan of the kiln was transformed, the traditional Y-A starting and auto-coupling reduction were eliminated, and the Panasonic inverter was installed. Taking a 62m long roller kiln as an example, the comparison of the air consumption of each fan and the various power consumption before and after the reformation of the surface kiln fan. The atomizing fan exhaust fan suction fan seal ten before the transformation (kwh) after the transformation (kwh) wind Under the premise of constant pressure, the following are the various power consumption statistics compared by the author (the kiln atomizing fan is connected to the combustion fan outlet pipe, only one fan is required).

According to the above table, per kWh.

According to the calculation of 52 yuan, the electricity consumption for the whole year (330 days) was 164,736 yuan before the transformation, and 83,160 yuan after the transformation, saving 81,576 yuan. According to the transformation of 3 fans per kiln, each inverter is 6,000 yuan, and the investment can be recovered in 2.5 months.

Yixing Jingtao Co., Ltd. has a total of 1 roller kiln. According to the above calculation, it can save 800,000 yuan in electricity costs throughout the year, and the power saving effect is very obvious.

Of course, the frequency conversion controller will also produce new problems during use, mainly because it may generate multiple harmonics during use, which will affect the surrounding electronic equipment and have a certain interference to the nearby communication system, but it will affect the ceramic industry. Electrical equipment has little impact. With the rapid development of the electronics industry and the continuous advancement of frequency conversion control technology, these problems are gradually being solved.

4 Conclusion From the actual operation of Yixing Jingtao Co., Ltd., the application of frequency conversion control technology, the enterprise's power saving effect is very obvious. Although the one-time cost of frequency conversion control is relatively low when the equipment is put in, the investment recovery period is short. Therefore, the application of advanced technology not only brings economic benefits from power saving, but also saves a lot of equipment maintenance costs and labor hours. As a member of the ceramic industry, it is recommended that enterprise producers apply a large number of frequency conversion control technologies to take another solid step in the enterprise's production cost reduction work.