Cryocooler and cryocooler operation method
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Solution Overview
Problem
Cryocoolers currently generate coldness at temperatures around 4 K, which is not sufficient to achieve helium superfluid transition temperatures, limiting their ability to utilize lower temperatures for refrigeration applications.
Innovation Solution
A cryocooler system that includes an expander for expanding high-pressure helium and a compressor to recycle low-pressure helium, with temperature and pressure control mechanisms to maintain helium at 2.17 K or lower, utilizing a helium state diagram to optimize volumetric thermal expansion coefficients for enhanced cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional cryocoolers operate at 4K temperature, then they can provide stable cooling, but they cannot achieve helium superfluid transition temperatures
Solution Approach 1:
The patent applies parameter changes by precisely controlling helium pressure and temperature parameters to navigate the phase transition region. The system adjusts pressure parameters to maintain helium in the superfluid state below 2.17K, transforming the operational parameters from conventional 4K stable cooling to sub-2.17K superfluid cooling through controlled parameter variation.
Solution Approach 2:
The invention implements dynamics by enabling the cryocooler to dynamically adapt its operation in the critical 2.17K phase transition region. The system dynamically adjusts operating conditions to maintain stability during the transition from normal fluid to superfluid helium, allowing the cooling temperature to drop below 2.17K while preserving operational reliability through real-time parameter adjustment.
2Productivity
If helium pressure is increased to achieve lower temperatures, then cooling efficiency improves, but the system complexity increases
Solution Approach 1:
The patent employs feedback control mechanisms to monitor and adjust helium pressure and temperature in real-time. This feedback system automatically maintains optimal pressure conditions for maximum cooling efficiency while preventing excessive pressure increases, thereby improving productivity without proportionally increasing device complexity through intelligent control rather than purely mechanical solutions.
Solution Approach 2:
The invention replaces complex mechanical pressure control systems with more sophisticated but compact control mechanisms. By substituting purely mechanical pressure regulation with integrated sensor-and-actuator systems that provide precise control, the patent achieves high cooling efficiency while minimizing the space and complexity additions associated with pressure management.
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 system effectively generates coldness below 2.17 K, enabling the cryocooler to achieve superfluidity temperatures, improving cooling efficiency and allowing for stable operation at lower temperatures, thus providing a cost-effective solution for helium-4 superfluidity transfer.
Implementation Method 1
a cryocooler for developing coldness of 4 K or lower by expanding helium
Implementation Method 2
a compressor for compressing low-pressure helium, returned from the expander, to generate high-pressure helium
Implementation Method 3
utilizing a helium state diagram to optimize volumetric thermal expansion coefficients for enhanced cooling efficiency
Data Source
AI summary
In a cryocooler for developing coldness of 4 K or lower by expanding helium, an expander expands high-pressure helium. A compressor compresses low-pressure helium returned from the expander, to generate high-pressure helium, and supplies the high-pressure helium to the expander. When helium temperature in the expander is 2.17 K or lower, the pressure of the low-pressure helium is equal to or higher than pressure given by a curve, in a helium state diagram in which the horizontal axis is temperature and the vertical axis is pressure, along which helium's volumetric thermal expansion coefficient is 0.