Gradient Coil Thermal Management via Intermediary Connectors
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Solution Overview
Problem
Existing MRI systems face challenges in efficiently managing heat generated by gradient coils and RF shields, leading to inhomogeneous temperature distributions and hotspots, which can affect the quality of MRI scans and increase system complexity and cost.
Innovation Solution
The implementation of a thermal management system using first and second thermal connectors to create heat bridges between the cooling arrangement and the RF shield, and between different windings of the cooling tubes, respectively, to enhance heat dissipation and reduce hotspots without increasing the bore size of the MRI system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional cooling tubes are used for gradient coil cooling, then cooling function is provided, but inhomogeneous temperature fields and hot spots occur due to low thermal conductivity of resin material
Solution Approach 1:
A thermal connector made of thermally conductive material (such as metal) is introduced as an intermediary between the cooling tube and the gradient coil windings. This thermal connector serves as a heat bridge that efficiently transfers heat from multiple winding locations to the cooling tube, overcoming the low thermal conductivity of the resin material and eliminating hot spots without complicating the cooling arrangement.
Solution Approach 2:
The thermal connector is divided into multiple segments, with each segment positioned at different locations around the gradient coil windings. Each segment creates a localized heat bridge to specific winding sections, enabling distributed heat extraction throughout the coil assembly. This segmented approach ensures uniform temperature distribution while maintaining a simple cooling tube structure.
2Temperature
If thermal connectors are added to improve heat dissipation, then temperature homogeneity improves, but device complexity increases
Solution Approach 1:
The thermal connector serves multiple functions simultaneously: it acts as a heat bridge for thermal management, provides structural support for the gradient coil windings, and maintains electrical insulation between different coil sections. By combining multiple functions into a single component, temperature homogeneity is achieved without proportionally increasing assembly complexity.
Solution Approach 2:
The thermal connector is integrated with the existing gradient coil assembly structure, merging the thermal management function with the mechanical support structure. This integration allows heat dissipation improvement while minimizing additional components and assembly steps, as the thermal connector becomes part of the overall coil assembly rather than a separate add-on.
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 improves the homogeneity of the temperature field, reduces hotspots, and enhances the cooling efficiency of the gradient coil assembly, thereby maintaining the quality of MRI scans while simplifying the system design and reducing costs.
Implementation Method 1
cooling tubes (4) in which a cooling fluid (9) flows and which are in thermal contact with the gradient coils (3)
Implementation Method 2
first and second thermal connectors (7, 5) to create heat bridges between the cooling arrangement and the RF shield, and between different windings of the cooling tubes
Implementation Method 3
a cooling fluid (9) flows and which are in thermal contact with the gradient coils (3)
Implementation Method 4
This heating is mainly caused by eddy currents and resistive heating as current is passed through the gradient coil
Implementation Method 5
heat also originates from eddy current heating of the radiofrequency shield (RF shield) of the MRI system
Data Source
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AI summary
The invention relates to cooling a gradient coil (3) of a magnetic resonance imaging system (11). It is an object of the invention to provide an improved assembly of a magnetic resonance imaging apparatus with a gradient coil (3) which allows a cooling of the gradient coil (3) in such a way that a better homogeneity of the temperature distribution an reduced hot spots effects can be achieved. According to the invention, an assembly of a magnetic resonance imaging system is provided, the assembly (1) comprising at least one gradient coil (3), a cooling arrangement (2) for cooling the gradient coil (3), and an RF shield (6), wherein the cooling arrangement (2) comprises at least one cooling tube (4) which is configured to transport a cooling fluid (9) and which is disposed on and in thermal contact with the gradient coil (3), wherein the assembly further comprises a thermal connector arrangement with at least one of a first thermal connector (7) and a second thermal connector (5), the first thermal connector (7) disposed between the RF shield (6) and the at least one cooling tube (4) and in thermal contact with the RF shield (6) and the at least one cooling tube (4) thereby providing a radially extending connection between the RF shield (6) and the at least one cooling tube (4), and the second thermal connector (5) affixed to the at least one cooling tube (4) thereby providing a circumferentially extending thermal connection between windings of a first one of the at least one cooling tube (4) and/or different tubes of the at least one cooling tube (4).