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NANOFLUIDS FOR COOLING OF INSULATED-GATE BIPOLAR TRANSISTOR (IGBT)

IP.com Disclosure Number: IPCOM000194156D
Publication Date: 2010-Mar-19
Document File: 6 page(s) / 77K

Publishing Venue

The IP.com Prior Art Database

Abstract

The present invention discloses a cooling technique for power electronic devices such as, insulated-gate bipolar transistor (IGBT) in Magnetic Resonance Imaging (MRI) systems. The present cooling technique utilizes nanofluids as a coolant that enhances the heat transfer rates without any additional pressure drop in the nanofluids. The nanofluid coolant comprises nanoparticles of materials that include metals and non-metals.

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RP13341

NANOFLUIDS FOR COOLING OF INSULATED-GATE BIPOLAR TRANSISTOR (IGBT)

BRIEF ABSTRACT

    The present invention discloses a cooling technique for power electronic devices such as, insulated-gate bipolar transistor (IGBT) in Magnetic Resonance Imaging (MRI) systems. The present cooling technique utilizes nanofluids as a coolant that enhances the heat transfer rates without any additional pressure drop in the nanofluids. The nanofluid coolant comprises nanoparticles of materials that include metals and non-metals.

KEYWORDS

    Cooling technique(s), power electronic device(s), insulated-gate bipolar transistor, IGBT, nano fluid(s), heat transfer rate(s), nanoparticle(s), Magnetic Resonance Imaging, MRI, heat flux, temperature fluctuation(s), nano-diamond and liquid cooled cold plate(s)

DETAILED DESCRIPTION

    Insulated-gate bipolar transistors (IGBT) are three-terminal power semiconductor devices, and are known as fast switching electronic devices. The IGBTs is generally used in gradient drivers of Magnetic Resonance Imaging (MRI) systems. The gradient driver typically delivers current pulses to a gradient coil of the Magnetic Resonance Imaging (MRI) system. Further, the gradient drivers utilize the IGBTs to generate the current waveforms. The IGBTs rapidly switch on and off at frequencies greater than 10 KHz in order to generate the current waveforms. The rapid switching of the IGBTs creates die-level heat

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RP13341

fluxes of around 100 W/cm2. Due to generation of such heat fluxes and temperature fluctuations, performance of the IGBTs is reduced. Therefore, it is always desirable to lower the temperature of the IGBTs in order to achieve high performance during applications.

    Conventional techniques use liquid coolants in a high-performance cold plate that is attached to multiple IGBTs. The cold plate can comprise single or multiple channels (micro meters to few milli meters) through a metal plate that is attached to the packed IGBT. In other conventional techniques, multiple impinging jet or sprays are provided on the metal plate that is attached to the IGBTs surface. Further, due to development of miniaturization techniques, multiple IGBTs are available in a relatively compact size. As a result, there is a significant increase in the die level heat fluxes. Moreover, the liquid cooling techniques utilized in such conventional techniques are insufficient for cooling the IGBTs that are available in compact size. Accordingly, there exists a need in the state of art for developing an improved cooling technique for the compact sized IGBTs.

    The proposed technique discloses a nanofluid coolant that transfers the heat associated with power electronic devices such as, IGBT's in the MRI systems. The nanofluid coolant described herein is used for both direct and indirect cooling of IGBT's. The nanofluid coolant generally comprises a base fluid in combination with nano-particles.

    The nano-particles include various metals and non-metals. The...