Gradient Coil Cooling via Liquid Dielectric Medium
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic resonance imaging (MRI) systems face issues with partial discharge between gradient coils, leading to image artifacts, inefficient cooling, and long manufacturing cycles due to the use of epoxy-based materials with low partial discharge inception voltage and vacuum pressure impregnation procedures.
Innovation Solution
Employing a liquid dielectric medium, such as mineral oil with perchlorethylene, to electrically separate and cool gradient coils, which enhances breakdown voltage, reduces heat rise, and simplifies manufacturing by avoiding epoxy impregnation procedures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If epoxy-based resin is used to electrically separate gradient coils, then electrical separation is achieved, but partial discharge inception voltage is low and manufacturing cycles are long
Solution Approach 1:
The patent changes the physical state of the dielectric material from solid (epoxy resin requiring vacuum pressure impregnation) to liquid (dielectric fluid), which eliminates the need for complex impregnation procedures and significantly reduces manufacturing time while maintaining electrical separation functionality
Solution Approach 2:
The patent employs a liquid dielectric fluid that can be circulated through the gradient coil assembly, using hydraulic principles to enable both electrical separation and active cooling, replacing the static epoxy-based system with a dynamic fluid-based system
2Reliability
If epoxy-based resin is used to electrically separate gradient coils, then electrical separation is achieved, but cooling efficiency is poor
Solution Approach 1:
The liquid dielectric fluid serves multiple functions simultaneously: it provides electrical separation between gradient coils, acts as a cooling medium to remove heat, and enables active thermal management through circulation, replacing the single-function epoxy resin that only provided electrical isolation
Solution Approach 2:
The system uses a circulated liquid dielectric fluid that can be pumped through cooling channels, utilizing hydraulic flow to efficiently remove heat from gradient coils, thereby improving cooling efficiency compared to the static epoxy-based system
3Volume of moving object
If gradient coils are disposed near to one another, then space utilization is improved, but partial discharge occurs between coils
Solution Approach 1:
The patent introduces a liquid dielectric fluid as an intermediary substance between adjacent gradient coils, which fills the gaps and provides high dielectric strength to prevent partial discharge, allowing coils to be positioned closer together without compromising electrical insulation
Solution Approach 2:
The patent changes the dielectric medium from air or epoxy resin to a liquid dielectric fluid with superior dielectric properties, which increases the breakdown voltage and prevents partial discharge, enabling tighter coil spacing while maintaining reliability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution increases partial discharge inception voltage, improves gradient coil cooling efficiency, and shortens manufacturing cycles, reducing the occurrence of image artifacts and enhancing overall MRI system performance.
Implementation Method 1
a first and second gradient coil of the gradient coil assembly are disposed in a liquid dielectric medium
Implementation Method 2
a first and second gradient coil of the gradient coil assembly are disposed in a liquid dielectric medium... improves gradient coil cooling efficiency
Data Source
Figure 1
Figure 2~3
Figure 4~6
AI summary
Magnetic resonance imaging systems having gradient coil assemblies employing a liquid dielectric medium are provided. In one embodiment, a magnetic resonance imaging system (10) includes a gradient coil assembly (58, 60) with a plurality of gradient coils (26, 28, 30). In the gradient coil assembly (58, 60), at least two of the gradient coils (26, 28, 30) are electrically separated from one another by a fluid medium.