The reactive power consumption of the intermediate frequency induction electric furnace is mainly caused by the copper loss caused by the induction coil and the water cooling cable during the operation of the electric furnace, and its unit resistance has great influence on the copper loss. Now, some electric furnace manufacturers to reduce costs, most of the induction coil copper raw materials using low-cost, high resistance value of the complex copper rather than the low resistance value of No. 1 electrolytic copper, resulting in induction coil and water line resistance is higher, the unit Time power loss is relatively large.
High-quality high-purity copper, the surface color shiny, low resistance, good electrical conductivity, and poor quality copper is not all copper material, brass black and hard, because the impurities can not withstand high current, high heat Should be distinguished.
A large induction coil, water cable cross-sectional area
Large cross-section of copper wire and copper conductor cable, which not only can reduce the wire heat and voltage loss, but also increase the reliability of distribution lines, and to adapt to long-term development, but also from the economic point of view is also very good, Of the investment can be quickly recovered, the user in the long-term use can get more benefits.
By increasing the cross-sectional area of the induction coil and water cable,Induction Coil it can greatly reduce the current density and reduce the copper consumption of the power supply line and help reduce the working temperature of the coil and water cable, reduce the chance of scale formation, reduce the failure rate, Production costs, energy saving, increase the economic efficiency of enterprises.
Take the 0.5t 400kW IF furnace as an example, the induction coil is (dimensions) 30x25x2 (mm) rectangular hollow copper tube, the number of turns is 16, the coil diameter is 560mm. The working temperature is 80 ℃, the electric power factor is 0.1, The induction coil itself at 80 ℃ when the power consumption of 80.96kW. Similarly, the water cable diameter of 60mm, length 2m, calculated at 80 ℃ when the power consumption of 0.42kW • power supply line only two in the 80 ℃ when the power consumption of 8l.38kW.
Two reduce the induction coil, water cable operating temperature
Induction furnace melting induction coil and water cable working temperature, due to the existence of copper resistance temperature coefficient, the resistivity increases, the resistance becomes larger, power consumption increases, the mathematical equation is as follows:
From the formula (1), copper coil operating temperature of each rise of 10 ℃, the resistance increased by 4%, power loss is also increased by 4%. When the operating temperature of the induction coil is reduced from 80 ° C to 50 ° C, the power loss is reduced by 12%, which is a considerable loss for a larger power IF induction furnace. So the use of an effective cooling system to effectively reduce the temperature of the power supply line,Induction Coil try to avoid the formation of temperature rise -> resistance rise -> the temperature rise of this vicious cycle, reducing line loss.
Three copper coil surface insulation treatment
Copper coil surface insulation treatment can not be ignored, a good insulation treatment can prevent the coil ignition, serious can even cause copper breakdown or burn the negative power of the bad consequences. To prevent the coil itself can also effectively reduce the power consumption, shorten the smelting time, improve production efficiency. In the 10 ton furnace for the results of the test, after six months in operation, after a good insulation of the coil compared with the untreated coil, power consumption savings of 10%.
Unfortunately, the copper coil surface insulation in the industry has not yet attracted enough attention, and some manufacturers in order to save costs, not the coil insulation treatment,Induction Coil or just buy cheap insulating paint in the market for spraying, just to To ensure that the sale is a beautiful appearance effect.
Good surface insulation need to use high temperature, water resistance, high voltage level insulation paint, the use of better results are TSC-L ultra-high temperature insulation paint and APC-H + high temperature anti-arc insulation enamel, the two paint are for The use of IF furnace characteristics of the development of the two in terms of temperature and compression some differences, according to their actual use of the need to carefully choose.