Basic information
The power of the fan is 210Kw, and the shutter valve (wind deflector) is used to adjust and control the air volume, which runs 24 hours.Analysis of fan operation
Waste of electric energy
The fan power is 210Kw, and the damper is adjusted and controlled. The speed of the fan is constant, and the air volume is controlled by the baffle, resulting in the air volume is not proportional to the motor output power, resulting in a lot of energy waste.
2. Poor adaptability to load in production process
As the production load is changing, and the adjustment of the air door is also constantly changing. If the air volume is unstable, the air pressure will change, which will affect the work efficiency, the dust separation effect and the production quality of cement.
3. The motor starts to impact the power grid
The starting mode of motor is reduced. During the start-up process, the starting impulse current is 3-4 times of the high-voltage irregular current, which has a great impact on the power grid. Moreover, the operation is complex, the maintenance quantity is large, the equipment failure rate is high, the maintenance cost is high, which causes the shutdown loss.
Characteristics and effect of frequency conversion energy saving in fan system
1. There is no comparable superiority of frequency control
The energy saving effect is remarkable. According to the principle of fluid mechanics, the flow rate Q of fan pump load is directly proportional to the speed n, and the required power P is proportional to the cubic power of speed n. Therefore, when the air volume is less than the rated air volume, changing the motor speed will significantly reduce its power, which has significant energy saving effect.
2. The efficiency of fan is improved
The working efficiency of the fan is calculated by the following formula:
ηp=C1（Q/n）-C2（Q/n）2
Where q is the air volume, n is the rotational speed, and C1C2 is a constant
When the air volume is controlled by the air door, the efficiency η P decreases because the speed n remains unchanged, while the flow rate Q decreases. When the air flow is controlled by the speed, the air flow is proportional to the rotating speed, and the ratio (Q / N) remains unchanged. Therefore, the efficiency η P is always in good condition.
3. The operation is simple and convenient, the amount of maintenance is small, and the working efficiency of the fan will be greatly improved. And realize the range of stepless speed regulation, because of starting, can make the motor continuous smooth and stable speed.
Benefit analysis
1. Save electricity
Taking the operation of 210Kw induced draft fan at 40Hz as an example, its working speed is 80% of the rated speed, and the power consumption of the fan is PZ = 0.83pn = 0.512pn. According to the 12-month production period every year, considering various losses, it is calculated as 20% power saving.
W=210KW×12×30×24×20%=362880KW.h.
Based on the price of 0.5 yuan per kilowatt hour, the electricity charge can be saved every year
362880 × 0.5 yuan = 181440 yuan
Return on investment analysis
The investment return period is calculated as follows:
One 280KW is calculated as 180000
Investment return = power saving benefit △ investment cost = 181440 △ 180000 = 100%
Return on investment period = 12 months ／ return on investment = 12 ／ 100% = 12 months
The above calculation is based on 20% energy saving. According to the actual energy saving rate range (20% - 60%), there is a large space for energy saving. Based on the frequency converter life of 8 years, one investment, long-term benefits.
summary
The transformation of the fan shows that:
1. It has the characteristics of simple structure, convenient transformation, obvious energy-saving effect and short payback period of investment.
2. After using the frequency converter, the fan can start and stop soft, reduce the mechanical impact of the equipment, extend the service life of the equipment, and reduce the maintenance cost of the equipment.
3. The frequency control technology is advanced and mature, which improves the technical content of the equipment.
