Analysis of Energy Saving Effect of Induction Coils in Induction Melting Furnace

Induction coils and water cables are partly improved . The reactive power consumption of induction melting furnaces is mainly the copper loss caused by the induction coils and water cables during the operation of the electric furnace. The unit resistance has a huge impact on the copper loss. At present, in order to reduce costs in some electric furnace production plants, most of the copper raw materials for induction coils use low-priced and high-resistance copper instead of low-resistance No. 1 electrolytic copper, which leads to high resistance of induction coils and water cables. The electrical loss per unit time is relatively large.

High-quality and high-purity copper tubes have bright surface color, low resistivity, and good electrical conductivity. Inferior copper uses not all copper materials, and the copper tubes are black and hard. Due to the large amount of impurities, they cannot withstand large currents and generate high heat. It should be distinguished when selecting materials.

① Increase the cross-sectional area of the induction coil and water cable. Copper wires and copper conductor cables with larger cross-sections can not only reduce the heating and voltage loss of the wires, but also increase the reliability of distribution lines and adapt to long-term development. It is also extremely beneficial from an economic point of view, increasing investment It can be recovered quickly, and users can get more benefits in long-term use.

By increasing the cross-sectional area of the induction coil and water cable, the current density can be greatly reduced, the copper consumption of the power supply line can be reduced, and the working temperature of the coil and water cable can be reduced, the probability of scale formation, the failure rate, and the saving Production costs, energy saving and consumption reduction, increase the economic benefits of enterprises.

To 0. 5t 400kW of induction melting furnace , for example, the induction coils (external dimensions) 30mmX25mm X- 2mm rectangular hollow copper tube, 16 turns, the coil diameter of 560mm, the operating temperature is 80 [deg.] C , electric power factor is 0.1, It is calculated that the power consumption of the induction coil itself at 80°C is 80.96kW. In the same way, the water cable has a diameter of 60mm and a length of 2m, and its power consumption at 80°C is calculated to be 0.42kW . Only these two power supply lines at 80 [deg.] C power consumption is at 81. 38kW O with increasing water induction coil and the cross-sectional area of the cable, the resistance change, the energy saving effect supply lines shown in Table 2-7.

■Table 2-7 Induction melting furnace coil wall thickness, water cable diameter increase and its energy-saving effect comparison

Coil wall thickness increase /mm	0	0.5	1	1.5	2	2.5	3
R’ /R/%	100	78.46	64. 15 г.	54. 97 г.	46. 36 г.	40. 48 г.	35.79
Increase in diameter of water cable /mm	0	5	10	15	20	25	30
Rt /R/%	100	85. 21 г.	73. 47 г.	64.00	56. 25 г.	49.83	44.44
Power saving/ (kW- h)	0	17. 50 г.	29.14	36. 61 г.	43. 61 г.	48. 40 г.	52. 22 г.
Total power saving of both/%	0	21.51	35.80	44.98	53. 59 г.	59.47	64.17

It can be seen from Table 2-7 that if the wall thickness of the induction coil is increased by 3mm and the diameter of the water cable is increased by 3cm, the hourly power consumption of the induction coil and the water cable will be increased by 64.17% and 52.22kW per hour , which is significant Save energy.