Application du variateur de fréquence Harsvert dans ventilateur brasseur d\'air
2009-12-15 13:52:29

I. Introduction

Tongli Cement Co., Ltd a été fondé en 1995 et est doté de deux lignes de production, avec une productivité journalière de 2500t et une productivité annuelle de 2 000 000t. En 2006, Tongli cement plant s’est procuré un Harsvert-A06/150 pour ajuster la vitesse. L’entraînement à fonctionné stablement depuis qu’il a pris en charge les opérations (janvier 2007) et l’économie en énergie est considérable.
II. Energy-saving effect

Circulating fan is driven by wire-wound motor. Its rated power is 6kV/1250kW. Before using VFD, air flow was adjusted by valve and there is much power loss on valve. Meanwhile, because valve was adjusted frequently, reliability of valve was not good, which affected system stability. After using VFD ( short connecting rotor winding), motor speed is adjusted by VFD. There is no need to adjust valve frequently and valve opens at a large scope.

Data in the site:

item	Before modification	After modification
Total material volume (t/h)	220	200
Given speed of VFD (r/min)	1000	820
Grinding head pressure(Pa)	13	160
Grinding tail pressure(Pa)	1000	1100
Motor current A	55	35
Noise	67	67
Outlet pressure(Pa)	2300	1800
Outlet temperature (℃)	78	52

We can see that motor current is lower after reconstruction with VFD and energy is saved a lot.

III. Characters of Harsvert VFD

Model	Harsvert-A06/150
Rated capacity	1565KVA
Rated current	150A
Rated voltage	6kV
Output frequency	0~50Hz
Motor power	1250kW
Acceleration/deceleration time	0~3200s
Over load capacity	120% for 60s, 150% for 3s, 200% immediately
Protection	Over voltage, low voltage, over current, over heat, earth, lack phase and so on.

IV Advantages
When motor starts, current increases from zero and will be not over rated current. So VFD avoids big current impact when motor starts, decreases maintaince, improves system safety.

V. Conclusion
Adjusting speed by VFD is not only easy and convenient but also saves much energy. It improves system safety and manufacture process.