电磁供暖系统中电磁感应加热器性能数值模拟

Numerical Simulation of Electromagnetic Induction Heater Performance in Electromagnetic Heating System

介绍电磁供暖系统、电磁感应加热器的结构和工作原理。利用COMSOL Multiphysics软件建立了电磁感应加热器的几何模型并划分网格进行模拟。对某文献中具有相似结构的电磁式水加热器实验进行同参数下的模拟,验证了加热器几何模型建立的准确性。通过分析线圈、发热管结构参数改变下加热器涡流场、温度场、磁场的特性及分布,得到不同设计参数对电磁感应加热器加热性能的影响规律。加热器线圈可选择电导率高、电阻率小的铜线线圈。通过数值模拟得出在电源励磁频率为5 kHz,发热管材料为马氏体不锈钢410,外半径为27 mm,壁厚2 mm情况下,线圈直径为4.0 mm、绕制匝数为50匝、励磁电流强度为40 A的线圈参数下的电磁感应加热器具有较高的磁电效率及水热效率。加热器发热管平均有效功率与管长、管径、电导率等因素有关,发热管外半径及壁厚的设计选择需适应散热器、供暖管道的尺寸范围要求。在线圈直径为4.0 mm、绕制匝数为50匝、励磁电流强度为40 A的线圈参数下,发热管外半径25 mm、壁厚2 mm具有较优的加热效率,总效率可达95.29%。

The electromagnetic heating system and structure and working principle of electromagnetic induction heater are introduced.The geometric model of the electromagnetic induction heater was established by COMSOL Multiphysics software,and the mesh was divided for simulation.The experiment of electromagnetic water heater with similar structure in a reference was simulated under the same parameters,and the accuracy of the geometric model of the heater was verified.By analyzing the characteristics and distribution of eddy current field,temperature field and magnetic field under the change of the structure parameters of the coil and heating tube,the influence law of different design parameters on the heating performance of electromagnetic induction heater was obtained.The heater coil can choose a copper wire coil with high conductivity and low resistivity.Through numerical simulation,it is concluded that the electromagnetic induction heater has high magnetoelectric efficiency and water heating efficiency when the excitation frequency is 5 kHz,the heating tube material is martensitic stainless steel 410,the outer radius is 27 mm,the wall thickness is 2 mm,the coil diameter is 4.0 mm,the number of winding turns is 50 turns,and the excitation current is 40 A.The average effective power of the heater heating tube is related to tube length,tube diameter,electrical conductivity and so on.The design and selection of the heating tube radius and wall thickness should meet the requirements of the size range of the radiator and heating pipeline.Under the coil parameters with a coil diameter of 4.0 mm,winding turns of 50 turns and excitation current of 40 A,the heating tube with outer radius of 25 mm and wall thickness of 2 mm has an excellent heating efficiency,and the total efficiency can reach 95.29%.