Numerical Study on the Heat Dissipation Effect of the Water-Cooled Structure of the Lateral Flange on the Pulsed Strong Magnetic Coil

Pulse strong magnetic coil can generate pulse strong magnetic field, and it can be applied to electromagnetic molding, electromagnetic emission, pulse power supply, and other fields. While the coil generates a strong magnetic field through a large current pulse, the coil temperature increases sharply due to Joule heating. The thermal conductivity of the insulating material in the coil is low, the heat is difficult to release after a single discharge, the heat continues to accumulate after continuous discharge, and the temperature will continue to rise. Excessive temperature will cause the insulation material to age, shorten the service life of the coil, and cause structural damage to the coil. Therefore, aiming at the problem that the temperature rise of the pulse strong magnetic coil is too high under continuous discharge, a method of heat dissipation of the coil by the water-cooled structure of the side flange is proposed. A 3-D transient coupling heat transfer model for pulsed strong magnetic coil with liquid cooling mode is established. A temperature rise test was designed to verify the accuracy of the coupling model. By comparing with the temperature rise of the coil under natural cooling conditions, the heat dissipation effect of the water-cooled structure on the pulsed strong magnetic coil after continuous discharge is analyzed. The results show that within the safety threshold (120 °C) of epoxy resin, the coil under natural heat dissipation conditions can be discharged eight times, and the maximum temperature of the coil after eight discharges is 102 °C under the water-cooled conditions of the side flange with a discharge interval of 300 s, a flow rate of 3 m/s, and an inlet water temperature of 20 °C. More discharges can be performed with a water-cooled coil. In addition, the effects of continuous discharge on coil heat dissipation under different water temperatures (0 °C, 20 °C), different flow rates (3, 5 m/s), and different discharge intervals (50, 300 s) were analyzed. For different loading conditions, the discharge interval has the greatest impact on the coil heat dissipation, followed by the inlet temperature, and the flow rate has the least impact on it.