Lead-Based Reactor Load-Following with Phase Change Heat Buffering
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Solution Overview
Problem
Lead-based reactors with autonomous load-following function face issues such as flow rate divergence, thermal fatigue of structural components, and high safety risks due to rapid temperature fluctuations and slow response times during power adjustments.
Innovation Solution
Incorporating a phase change energy storage device with a consistent phase change temperature matching the reactor core inlet temperature, a thermal energy utilization device, and adjustable reflective layers to manage neutron leakage, allowing for controlled power adjustments and stable core inlet temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If autonomous load-following control is implemented by adjusting natural-circulation flow rate, then power can automatically change with external load, but temperature changes cannot match flow changes causing flow rate divergence and flow oscillation
Solution Approach 1:
A thermal energy storage device is introduced as an intermediary component between the reactor core and the external load. This device buffers temperature changes and releases heat gradually, mediating the mismatch between rapid flow rate adjustments and slower temperature response, thereby preventing flow oscillation and divergence while maintaining autonomous load-following capability
Solution Approach 2:
The thermal energy storage device performs preliminary heat storage during high-power operation, so when load decreases and flow rate needs to increase rapidly, the stored heat is released to maintain core temperature. This preliminary action prevents the temperature-flow rate mismatch that causes instability
2Speed
If core power is adjusted rapidly to match external load changes, then response speed improves, but core temperature becomes excessive due to slow natural circulation re-establishment
Solution Approach 1:
The thermal energy storage device acts as a heat buffer that absorbs excess heat when core power increases rapidly and releases heat when power decreases. This intermediary function prevents core temperature from becoming excessive during rapid power adjustments while maintaining fast response capability
Solution Approach 2:
The thermal energy storage device provides beforehand cushioning by storing heat capacity in advance. When rapid power adjustments occur, this pre-stored thermal capacity cushions against temperature excursions, preventing core temperature from becoming excessive during transient periods before natural circulation re-establishes
3Temperature
If natural circulation flow rate is adjusted to match temperature changes, then temperature stability improves, but response speed becomes slow
Solution Approach 1:
The thermal energy storage device serves as a mediator that decouples the relationship between flow rate adjustments and temperature changes. It allows flow rate to respond rapidly to load changes while the device handles temperature buffering, achieving both fast response and temperature stability without requiring slow natural circulation adjustments
4Speed
If rapid heating and cooling occurs during load following, then power adjustment speed improves, but thermal fatigue of structural components increases
Solution Approach 1:
The thermal energy storage device provides beforehand cushioning against thermal shocks to structural components. By absorbing and releasing heat gradually, it prevents rapid heating and cooling cycles that would cause thermal fatigue, allowing fast power adjustment while protecting component strength and durability
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 buffers thermal changes, stabilizes natural circulation, reduces thermal fatigue, and enhances safety by maintaining consistent core inlet temperature, thus preventing flow oscillation and structural damage, ensuring safe and timely power adjustments.
Implementation Method 1
a phase change energy storage device is provided at an inlet side of the reactor core, and configured for exchanging heat with the coolant
Implementation Method 2
the phase change temperature of the phase change energy storage device is consistent with a preset inlet temperature of the reactor core
Implementation Method 3
the reactor core is configured for heating a coolant
Implementation Method 4
the reactor core is configured for heating a coolant
Implementation Method 5
the thermal energy utilization device is configured for absorbing heat in the coolant
Implementation Method 6
an adjustable reflective layer is provided on the outside of the reactor core... the adjustable reflective layer is configured to be movable relative to the fixed reflective layer to adjust a shielding area of the notch
Data Source
AI summary
The nuclear-energy storage integrated lead-based reactor with an autonomous load-following function includes a reactor core, a phase change energy storage device, and a thermal energy utilization device; the reactor core is configured for heating a coolant, and the thermal energy utilization device is configured for absorbing heat in the coolant; the phase change energy storage device is provided at an inlet side of the reactor core, and configured for exchanging heat with the coolant, and a phase change temperature of the phase change energy storage device is consistent with a preset inlet temperature of the reactor core. The nuclear-energy storage integrated lead-based reactor has a natural circulation flow rate that is not easy to oscillate and diverge, the fuel assembly does not have the risk of overheating and melting, and the structural components are not easy to suffer from thermal fatigue, and it has high safety performance.