Passive flow direction biasing of cryogenic thermosiphon
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Solution Overview
Problem
Existing thermosiphon cooling devices for superconducting magnets do not guarantee counter-flow in the heat exchanger, leading to reduced heat transfer efficiency and making it difficult to ensure optimal flow direction, especially in systems where geometrical placement in a gravity field is not feasible.
Innovation Solution
Incorporating passive one-way valves in the primary and secondary coolant circuits to ensure counter-flow in the heat exchanger by allowing flow in specific directions and blocking opposite directions, ensuring efficient heat exchange and reliable startup of the thermosiphon cooling system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If passive thermosiphon flow is used in the secondary cooling circuit, then startup can be performed with only gas helium, but the flow direction in the heat exchanger cannot be guaranteed, leading to reduced heat transfer efficiency
Solution Approach 1:
The system uses passive one-way valves that automatically control flow direction without requiring external control systems or additional energy input. The valves self-regulate based on pressure differentials created during operation, ensuring counter-flow in the heat exchanger while maintaining the simplicity of passive thermosiphon startup
Solution Approach 2:
The patent introduces one-way valves that change the flow parameters (direction) based on pressure differentials. These valves remain closed during startup allowing gas helium operation, then open to enforce counter-flow once liquid helium is present, dynamically adjusting flow characteristics to optimize heat transfer efficiency
2Ease of operation
If geometrical placement in gravity field is used to control flow direction, then passive thermosiphon flow can be achieved, but it is not feasible in all system configurations
Solution Approach 1:
The one-way valves act as intermediary devices that mediate between the gravitational field and the coolant flow. They translate pressure differentials into controlled flow directions, enabling passive thermosiphon operation in configurations where direct gravitational control through geometrical placement would be impractical or impossible
3Device complexity
If counter-flow is not guaranteed in the heat exchanger, then system simplicity is maintained, but heat exchange efficiency is reduced
Solution Approach 1:
The one-way valves automatically enforce counter-flow conditions without requiring complex control systems, variable geometry mechanisms, or additional energy input. The valves self-regulate based on inherent pressure differentials during operation, maintaining system simplicity while ensuring optimal heat exchange efficiency through guaranteed counter-flow in the heat exchanger
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
The solution provides improved and reliable startup of the thermosiphon cooling system, ensuring efficient heat exchange by guaranteeing counter-flow in the heat exchanger, which enhances the cooling efficiency and stability of the cryogenic thermosiphon cooling system, particularly in systems where geometrical placement is not sufficient to control flow direction.
Implementation Method 1
A first passive one way valve is disposed on the first flow loop and is oriented to allow flow in an allowed direction of flow in the first flow loop and to block flow in an opposite blocked direction of flow in the first flow loop
Implementation Method 2
a heat exchanger, a first flow loop connecting a cold sink and the heat exchanger, and a second flow loop connecting a hot sink and the heat exchanger
Implementation Method 3
Another known approach for cooling a superconducting magnet employs a thermosiphon
Implementation Method 4
promoting passive thermosiphon flow in the secondary cooling circuit
Data Source
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AI summary
A cooling device (40) includes a heat exchanger (50), a first flow loop (52) connecting a cold sink (42, 44, 46) and the heat exchanger, and a second flow loop (54) connecting a hot sink (20) and the heat exchanger. A first passive one way valve (62) disposed on the first flow loop is oriented to allow flow in an allowed direction of flow (F1) and to block flow in the opposite direction. A second passive one way valve (64) disposed on the second flow loop is oriented to allow flow in an allowed direction of flow (F2) and to block flow in the opposite direction. The allowed directions of flow produce counter-flow in the heat exchanger. In an illustrative embodiment, the hot sink is comprises a cryogenic magnet coil (20) and the hot sink is a cold head (42, 44) and liquid helium tank (46).