MR System Cooling Circuit Using Heat Source to Prevent Coolant Freezing

Solution Overview

Problem

Magnetic resonance examination systems face challenges in efficiently removing heat from components like gradient coils and RF amplifiers without the need for antifreeze, especially at low temperatures, which can lead to freezing of the cooling fluid.

Innovation Solution

A simplified cooling circuit system that utilizes a heat source, such as a cryocooler, to maintain the temperature of the cooling fluid above freezing, eliminating the need for antifreeze by using a low-viscosity coolant like water and employing a backup pump to ensure continuous fluid flow, even if the main pump fails.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a cooling circuit uses water as coolant without antifreeze, then heat transfer efficiency is improved and viscosity is reduced, but the cooling fluid freezes at low temperatures

Engineering Contradiction:

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

A heating element is introduced as an intermediary device in the cooling circuit to prevent freezing of the water coolant. The heating element acts as a mediator between the cooling function and the anti-freezing requirement, allowing water to be used as coolant while preventing it from freezing at low temperatures.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The temperature parameter of the cooling fluid is actively controlled by the heating element to maintain it above the freezing point. By dynamically adjusting the heating power based on temperature feedback, the system maintains water in a liquid state while preserving its high heat transfer efficiency.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If antifreeze is added to the cooling circuit, then the freezing risk is reduced, but heat transfer efficiency decreases and viscosity increases

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

Instead of adding antifreeze chemicals to the coolant, a heating element is introduced as an external intermediary to prevent freezing. This approach maintains the purity and thermal properties of the water coolant while providing freezing protection through active heating.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The chemical solution (antifreeze additives) is replaced with a thermal solution (heating element). This substitution maintains the physical and chemical properties of water as coolant while achieving the same freezing protection goal through thermal energy input.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If the main pump fails, then the system complexity is reduced, but the cooling function is lost and heat cannot be removed

Engineering Contradiction:

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

A backup pump is installed in parallel with the main pump to provide cushioning against pump failure. This redundancy ensures that if the main pump fails, the backup pump can immediately take over to maintain cooling continuity, protecting the system from heat accumulation.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The backup pump serves as a standby component that remains inactive during normal operation but is activated when the main pump fails. This allows the system to maintain simplicity during normal operation while recovering full cooling functionality when needed through the backup pump.

Inventive Principle:

Principle #34Discarding and recovering

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 prevents freezing of the cooling fluid at low temperatures, reduces the risk of system failure, and allows for efficient heat transfer, thereby extending the operational life of the magnetic resonance examination system without the need for antifreeze, which would decrease efficiency.

Implementation Method 1

wherein said heat source is arranged in thermal correspondence with the short-circuit, so that the temperature of cooling fluid inside the short-circuit is affected by the heat source

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

including a main pump arranged in the system cooling circuit to drive fluid flow in the system cooling circuit

Methodology Applied

Scientific EffectPumping: Pump

Implementation Method 3

A system cooling circuit in thermal correspondence with the cooling client and in thermal correspondence with a heat drain

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3374780B1Magnetic resonance examination system with fluid cooling arrangement

Publication Date: 2021.09.01

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AI summary

A magnetic resonance examination system comprises cooling clients (113, 144, 115) from which heat is carried-off by way of a system cooling circuit. A heat source (109) is in thermal contact with the system cooling circuit. A main pump (107) drives flow of the coolant in the system cooling circuit. The coolant is kept in motion and may be heated by the heat source. Thus, freezing of the coolant is avoided without the need of antifreeze. A back-up pump (121) of lower performance requirements may maintain flow of the coolant even if the main pump fails. A low viscosity coolant, such as water may be used. The system also contains a shut-off valve (127) and a short-circuit (141) parallel to the shut-off valve.