Thermomagnetic liquid cooling: A novel variable speed motor drives thermal management solution

Abstract

Liquid cooling for thermal management has been extensively applied in high power electronic systems. However, the use of pumps may introduce reliability and mechanical limitations such as vibration, noise, leakage, and considerable power consumption. It has been shown that temperature sensitive ferrofluids in the presence of temperature field and magnetic field gradients are able to produce a liquid flow without a mechanical pump. This paper presents results from experiments using a single-phase, MnZn ferrite based ferrofluid operating under transient and steady laminar flow conditions in a partially heated thermomagnetic circulation loop under the influence of an external magnetic field created by a solenoid. The effects of several operational factors on the system performance are discussed. Additionally, the self-regulating feature of this cooling system is demonstrated as the heat load is increased a larger heat dissipation rate can be managed due to a stronger thermomagnetic convection effect.

A critical review on thermal management technologies for motors in electric cars

“…Nevertheless, placing the channel located nearer the winding will surely benefit the temperature decrease [150], but may cause an increase of losses. The most common working fluid is water, while the oil, water/glycol, and even dielectric fluid, thermomagnetic fluid are also available to cool the motor [151,152]. No matter what coolant is used, the optimizations of the channel dimensions and flow rate are proved efficient ways to improve the heat transfer ability of jacket cooling.…”