Superconducting magnet system including thermally efficient ride-through system and method of cooling superconducting magnet system
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Solution Overview
Problem
Superconducting magnet systems face significant challenges during power outages or cryocooler malfunctions, leading to rapid temperature increases and quenching, which result in cryogenic fluid loss and potential damage, requiring costly and time-consuming recovery processes, especially in sealed systems with limited cryogenic fluid volumes.
Innovation Solution
A ride-through system incorporating a thermal regenerator, multiple heat exchangers, and storage devices to manage boiled-off gas, preventing quenching and allowing extended operation without external refrigeration, and enabling quick recovery by storing and efficiently reusing cryogenic fluid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cryocooler stops operating due to power loss or malfunction, then the system can continue operating temporarily, but the temperature of the superconducting magnet will rise to critical temperature causing quenching and cryogenic fluid loss
Solution Approach 1:
The system pre-cools and stores a large volume of cryogenic fluid (1000 liters of liquid helium) in the cryostat before operation. This preliminary action ensures that when the cryocooler stops operating, there is sufficient cold mass to maintain the magnet temperature below critical temperature for an extended period, preventing quenching during power outages or maintenance.
Solution Approach 2:
The system incorporates a large thermal mass of cryogenic fluid as a cushion against temperature rise. This cushioning effect absorbs the thermal energy that would otherwise cause the magnet to quench, providing a safety buffer that allows the system to ride through cryocooler failures without losing cryogenic fluid or requiring immediate intervention.
2Duration of action of moving object
If a large volume of cryogenic fluid is used to extend operation time, then the thermal mass increases providing longer ride-through capability, but the system size and cost increase
Solution Approach 1:
The system changes the physical parameters of the cryogenic fluid storage by using a large volume (1000 liters) of liquid helium at cryogenic temperatures. This parameter change creates a substantial thermal mass that extends the ride-through time from minutes to days, allowing the magnet to operate independently of continuous external refrigeration while maintaining a manageable system footprint through efficient thermal management.
3Productivity
If the cryocooler is turned off for maintenance or the power is lost, then operational continuity is disrupted, but with proper preparation the system can recover quickly without technician intervention
Solution Approach 1:
The system is pre-prepared with sufficient cryogenic fluid storage capacity to maintain operation during cryocooler maintenance or power loss. This preliminary preparation ensures that when the cryocooler is turned off for maintenance, the magnet continues to operate without interruption, and recovery is achieved automatically without requiring technician dispatch or manual intervention.
Solution Approach 2:
The system is designed to be self-sufficient during cryocooler outages, using its internal cryogenic fluid reserves to maintain magnet operation. This self-service capability allows the system to automatically ride through failures and recover without external assistance, maximizing productivity and minimizing downtime while reducing operational costs.
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 delays or prevents magnet quenching, reduces the need for external cryogenic refills, and facilitates rapid restoration of superconducting operation, minimizing downtime and costs by utilizing stored cryogenic fluid and thermal management techniques.
Implementation Method 1
one or more gravity-fed cooling tubes thermally connected at a lower end thereof to the superconducting magnet and connected at an upper end to a first heat exchanger
Implementation Method 2
cooling the superconducting magnet with the cold gaseous helium circulating therein
Implementation Method 3
first heat exchanger configured to have a second cryogenic fluid disposed therein and thermally connected via a cooling loop to the second stage element of the cryocooler
Implementation Method 4
the first heat exchanger is disposed at a top portion of the one or more gravity-fed cooling tubes
Implementation Method 5
power is still supplied to a compressor which drives a cooling unit or 'cold head' - herein referred to as a 'cryocooler' - in order to maintain the temperature of the superconducting magnet near absolute zero
Implementation Method 6
the superconducting magnet maintains the current and the magnetic field due to its superconductivity
Implementation Method 7
A ride-through system incorporating a thermal regenerator, multiple heat exchangers, and storage devices to manage boiled-off gas
Implementation Method 8
storing and efficiently reusing cryogenic fluid
Data Source
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AI summary
A superconducting magnet system, including a cryostat, and a ride-through system for the superconducting magnet system include: one or more gravity-fed cooling tubes configured to have therein a cryogenic fluid; a first heat exchanger configured to transfer heat from the one or more gravity-fed cooling tubes to a cryocooler; a storage device having an input connected to the first heat exchanger and configured to receive and store a boiled-off gas from the first heat exchanger; and a thermal regenerator having an input connected to the output of the storage device.