Cryogenic Cooler Circuit With Passive Valves for Redundant Isolation
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Solution Overview
Problem
Existing cryogenic cooler systems face challenges in thermal isolation of redundant coolers, leading to thermal conduction and inefficiencies, particularly in space applications where maintenance is difficult, and prior solutions require complex configurations like counter-current exchangers that incur high pressure drops and radiation losses.
Innovation Solution
A cryogenic cooler design incorporating passive check valves, such as Tesla diodes, and a heat-transfer fluid circuit with multiple heat-exchange areas and buffer tanks, allowing for efficient cold extraction and thermal disconnection without counter-current exchangers, enabling effective thermal management and reduced thermal load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a redundant cryogenic cooler is implemented for safety, then reliability is improved, but thermal conduction from the redundant cooler to the active cooler causes heat supply and reduces thermal efficiency
Solution Approach 1:
The system divides the thermal management into separate thermal loops for the active and redundant coolers. Each cooler has its own independent thermal circuit, allowing the redundant cooler to be thermally isolated when not in use, preventing heat conduction to the active cooler while maintaining reliability through redundancy.
Solution Approach 2:
A heat transfer fluid circulates through separate thermal loops acting as an intermediary between each cooler and the cold areas. By controlling the circulation of this fluid in each loop independently, the system can activate or deactivate thermal pathways without direct thermal contact between the redundant and active coolers.
2Loss of energy
If a thermal loop with heat-transfer fluid circulation is used to decouple the redundant cooler, then thermal isolation is improved, but the system complexity increases due to additional circulators and fluid circuits
Solution Approach 1:
The system combines the thermal loops of both coolers into a unified fluid circuit architecture. The same heat transfer fluid serves both the active and redundant cooler loops, and the check valves are integrated into a common circuit rather than requiring separate independent systems, reducing overall complexity.
Solution Approach 2:
The check valves automatically control the direction of heat transfer fluid circulation based on pressure differentials, eliminating the need for external mechanical circulators or complex control systems. The system self-regulates thermal pathways through passive valve mechanisms that respond to operational conditions.
3Productivity
If check valves are used to rectify the alternating pressure and flow-rate wave, then continuous flow is achieved, but pressure drops increase and radiation losses occur in the heat-exchangers
Solution Approach 1:
The system replaces complex mechanical flow control mechanisms with passive check valves that use elastic deformation and pressure differential to control flow direction. This substitution reduces mechanical complexity and energy losses associated with active flow control systems while achieving continuous flow rectification.
Solution Approach 2:
The check valves are designed with specific elastic properties and geometric parameters that allow them to respond to pressure wave characteristics. By optimizing the valve parameters to match the operating pressure and flow conditions, the system minimizes pressure drops while maintaining effective flow rectification and continuous circulation.
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 configuration achieves improved thermal efficiency, reduced thermal conduction, and the ability to operate at lower temperatures, such as 15K, while simplifying the distribution of cold power and reducing the thermal load from redundant coolers, enhancing the reliability and efficiency of cryogenic cooling systems.
Implementation Method 1
a piston generating a pressure and flow-rate wave in the gas. The pressure and flow-rate wave will be used to generate cold on a cold finger of the system
Implementation Method 2
The pressure and flow-rate wave generator transmits the pressure and flow-rate wave in the cold finger which allows generating cold down to a determined temperature in the range of −200° C. and even lower
Implementation Method 3
a heat-transfer fluid is made to circulate between the cold area and the member to be cooled
Implementation Method 4
there is still some thermal conduction in its cold finger because in order to ensure the switch between the coolers in case of deficiency of either one, they cold areas shall be thermally connected
Implementation Method 5
this heat-transfer fluid is conveyed in a «counter-current» heat-exchanger
Implementation Method 6
the extraction, called «hot-extraction», of the heat-transfer fluid is done when the heat-transfer fluid is hot from a transfer line connecting the pressure and flow-rate wave generator and the cold area, then this heat-transfer fluid is conveyed in a «counter-current» heat-exchanger
Implementation Method 7
connecting the loop to the outlet of the pressure and flow-rate wave generator by a system of check valves so as to rectify the alternating pressure and flow-rate wave in a continuous flow
Implementation Method 8
at least one application heat-exchanger configured to exchange calories with at least one device to be cooled
Data Source
AI summary
A cryogenic cooler includes a cold region, a heat-transfer fluid circuit, the cold region being positioned in the circuit, and an application heat exchanger configured to exchange calories with a device to be cooled. The cooler includes at least one passive non-return valve fluidly connected to the cold region, the heat exchanger having at least one first fluid inlet positioned downstream of the non-return valve in the flow direction of the heat-transfer fluid, the heat-transfer fluid circulating from the end of the cold region.