System for warming-up and cooling-down a superconducting magnet
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cryogenic refrigeration systems face challenges in warming and cooling superconducting magnets and other cryogenic systems without moving the cryostat or breaking the vacuum, which is essential for servicing and maintaining these systems at cryogenic temperatures.
Innovation Solution
A portable servicing system that circulates gaseous cryogen through a cryostat using GM or Brayton cycle expanders and compressors, with vacuum jacketed lines and a control system to manage fan speed, heater power, and expander speed, allowing for warming and cooling without moving the cryostat or breaking the vacuum.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a cryogenic refrigeration system is used to cool a superconducting magnet, then the magnet can operate at cryogenic temperatures, but the system becomes complex and difficult to service without breaking vacuum
Solution Approach 1:
The system is divided into separate functional modules: a portable refrigeration unit that can be moved to the magnet location, vacuum jacketed transfer lines for cryogen delivery, and a servicing system that operates independently of the main cryostat. This segmentation allows the complex refrigeration function to be separated from the magnet, simplifying servicing procedures.
Solution Approach 2:
A portable servicing system acts as an intermediary between the external environment and the cryogenic magnet. This system includes vacuum jacketed transfer lines that deliver cryogen to the magnet without breaking the vacuum seal, and can be connected or disconnected without affecting the magnet's vacuum environment.
2Ease of operation
If the cryostat is moved for servicing, then access to the magnet is improved, but the vacuum is broken and the system must be re-cooled
Solution Approach 1:
The refrigeration system is extracted from the cryostat and made portable. The portable servicing system can be moved to the magnet location and connected through vacuum-sealed interfaces, allowing servicing to occur without breaking the magnet's vacuum or requiring the magnet to be re-cooled from ambient temperature.
Solution Approach 2:
The portable servicing system is pre-positioned and pre-connected to the magnet through vacuum jacketed transfer lines before servicing is needed. This allows the system to be ready for immediate operation, eliminating the time required to re-establish vacuum and re-cool the magnet after servicing.
3Ease of repair
If the magnet is warmed to room temperature for servicing, then access and maintenance are improved, but the warm-up and cool-down times are extended
Solution Approach 1:
The portable refrigeration system maintains continuous cooling capability during servicing operations. The system can deliver cryogen to the magnet throughout the servicing process, allowing the magnet to remain at cryogenic temperature while maintenance is performed, thereby eliminating warm-up and cool-down cycles.
Solution Approach 2:
The servicing system is designed to be dynamically adaptable, allowing it to operate in different modes: continuous cooling during servicing, controlled warm-up when necessary, and rapid cool-down when needed. This dynamic operation optimizes both maintenance accessibility and time efficiency.
4Ease of operation
If a portable servicing system is designed to be moved through standard doors, then ease of deployment is improved, but the system size and capacity are constrained
Solution Approach 1:
The portable refrigeration system employs a nested configuration where components are arranged concentrically or in compact layers. The vacuum jacketed transfer lines are nested within the portable refrigeration unit, and the expander and compressor are integrated in a space-efficient manner, allowing the system to fit through standard doors while maintaining adequate cooling capacity.
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
Enables efficient warming and cooling of cryogenic systems, minimizing warm-up and cool-down times, and can be used on systems operating below 100 K, with the ability to be moved through standard doors and operated by one or two people, effectively managing the temperature range from ambient to cryogenic levels.
Implementation Method 1
A portable servicing system that circulates gaseous cryogen through a cryostat using GM or Brayton cycle expanders and compressors
Implementation Method 2
U.S. Pat. No. 8,448,461 by Longsworth describes an engine operating on the Brayton cycle that is designed for fast cool down of a MRI magnet to less than 40 K
Implementation Method 3
vacuum jacketed lines and a control system to manage fan speed, heater power, and expander speed
Implementation Method 4
heater power, and expander speed, allowing for warming and cooling without moving the cryostat or breaking the vacuum
Data Source
AI summary
A cryogenic refrigerator system with heaters is constructed in modular form to serve as a portable servicing system to warm up and then cool down a target object by circulating a gaseous cryogen through a target object cryostat without moving the target object or breaking its vacuum. The main module is a refrigerator cryostat containing a fan that circulates gas through one or more heat exchangers which can warm or cool the gas by heaters and by one or more GM or Brayton cycle expanders. Additional components including one or more compressors, a gas charge and vent assembly, a control system, gas lines, power lines, and vacuum jacketed transfer lines can be assembled in the main module or additional modules. An example is a system that can be wheeled through a hospital to service a MRI cryostat.