Superconductor Cooling with Sub-Cooling Tank Backup
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Solution Overview
Problem
The existing cooling apparatus for superconducting cables requires high costs and large installation spaces due to the need for multiple refrigerators, and there is a risk of temporary temperature rises when switching to a backup refrigerator, potentially compromising the superconductive function.
Innovation Solution
A cooling apparatus with a sub-cooling tank, secondary heat exchanger unit, depressurizing unit, temperature detection, and fault detection system that allows for continuous cooling of the superconductor by controlling the secondary coolant temperature using the sub-cooling tank and secondary heat exchanger unit, eliminating the need for additional refrigeration units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple refrigerators are prepared for backup cooling, then the reliability of superconductor cooling is improved, but the cost and installation space increase
Solution Approach 1:
The patent implements a nested cooling system where a secondary coolant storage tank is placed inside the existing coolant circulation system. The secondary coolant tank is positioned within the coolant pipeline, creating a compact nested structure that provides backup cooling capacity without requiring separate external refrigeration units. This nested configuration resolves the contradiction by integrating backup functionality into the existing system footprint.
Solution Approach 2:
The patent utilizes parameter changes by controlling the temperature of the secondary coolant through pressure adjustment. A temperature control device adjusts the pressure of the secondary coolant to maintain it at a predetermined sub-cooled temperature, enabling it to provide immediate backup cooling. This parameter-based control allows the system to switch between primary and secondary cooling modes without physical reconfiguration, maintaining reliability while avoiding the need for multiple full-scale refrigerators.
2Reliability
If a backup refrigerator is switched to during a fault, then the reliability is improved, but temporary temperature rise occurs during switching
Solution Approach 1:
The patent applies preliminary action by pre-cooling the secondary coolant to a sub-cooled temperature below the normal operating temperature before any fault occurs. The temperature control device continuously maintains the secondary coolant at this lower temperature through pressure adjustment. When a refrigerator fault occurs, the pre-cooled secondary coolant immediately takes over without requiring warm-up time, eliminating temporary temperature rises during the transition from primary to backup cooling.
3Temperature
If circulative cooling with sub-cooled coolant is used, then the superconductor is maintained at low temperature, but the system becomes vulnerable to temperature rise when refrigerator fails
Solution Approach 1:
The patent introduces the secondary coolant as an intermediary substance that mediates between the primary refrigeration system and the superconductor cooling requirement. The secondary coolant is stored in a dedicated tank within the circulation system and acts as a buffer or mediator that can immediately absorb heat from the superconductor if the primary refrigerator fails. This intermediary approach ensures continuous low-temperature maintenance while improving reliability through the backup 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
This solution prevents temperature rises and maintains superconductive conductivity without the need for extra refrigeration units, achieving a low-cost and compact cooling system even when a refrigerator fails.
Implementation Method 1
a depressurizing unit configured to reduce pressure in the sub-cooling tank to cool the secondary coolant stored in the sub-cooling tank
Implementation Method 2
a secondary heat exchanger unit which is disposed in the sub-cooling tank and which is configured to cool the coolant, having been used for cooling the superconductor, through heat exchange with the secondary coolant stored in the sub-cooling tank
Data Source
AI summary
A low-cost and space-saving cooling apparatus for a superconductor that prevents a function of the superconductor being compromised when a refrigerator is faulty.A cooling apparatus for a superconductor forms a circulation path in which a coolant, having been used for cooing the superconductor, is pumped by a circulation pump to a heat exchanger unit so that the coolant is cooled by a refrigerator, and the coolant is supplied to the superconductor. The cooling apparatus for a superconductor includes: a sub-cooling tank which is disposed on a downstream side of the superconductor and on an upstream side of the heat exchanger unit in the circulation path and which is configured to store a secondary coolant for cooling the coolant; a secondary heat exchanger unit which is disposed in the sub-cooling tank and which is configured to cool the coolant, having been used for cooling the superconductor, through heat exchange with the secondary coolant; a depressurizing unit configured to reduce pressure in the sub-cooling tank to cool the secondary coolant; a temperature detection unit for detecting temperature of the secondary coolant; a fault detection unit capable of detecting a fault state of the refrigerator; and a control unit configured to determine whether the refrigerator is faulty, based on information detected by the fault detection unit, and to control, upon determining that the refrigerator is faulty, an operation of the depressurizing unit so that the temperature of the secondary coolant, detected by the temperature detection unit, becomes a predetermined temperature at which the secondary coolant is capable of cooling the superconductor through the coolant.