Phase Change Thermal Storage Agglomerate Breakup
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Concentrated solar thermal power plants face inefficiencies due to temperature fluctuations and the formation of a solid phase change material agglomerate during the charging phase, which hinders liquid circulation and leads to power drops and increased costs in thermal storage systems.
Innovation Solution
A thermal storage device with a reservoir containing a phase change material and external heat exchangers, where means are provided to initiate liquid circulation paths within the agglomerate, reduce the agglomerate volume, and ensure unhindered liquid flow, using techniques like Joule effect heating and abrasion to manage the solid-liquid mixture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If phase change material is used for thermal storage, then storage density is improved, but thermal conductivity is insufficient
Solution Approach 1:
The patent uses composite materials by combining phase change material with graphite particles to create a composite phase change material that maintains the high storage density of PCM while adding the high thermal conductivity of graphite to overcome the thermal conductivity deficiency
Solution Approach 2:
The patent introduces graphite as an intermediary substance that acts as a thermal conduit between the heating element and the phase change material, facilitating heat transfer without requiring the PCM itself to have high thermal conductivity
2Device complexity
If passive latent heat storage system is used, then device complexity is reduced, but heat transfer surface area is insufficient
Solution Approach 1:
The patent transitions from a passive system relying on natural convection to an active system using forced circulation pumps, adding the dimension of mechanical energy input to enhance heat transfer efficiency without proportionally increasing system complexity
Solution Approach 2:
The patent employs hydraulic circulation systems with pumps to actively move the heat transfer fluid through the storage tank, creating forced convection that significantly increases heat transfer surface area utilization while maintaining manageable device complexity
3Use of energy by moving object
If phase change material solidifies during discharge, then latent heat is recovered, but power exchange decreases
Solution Approach 1:
The patent implements dynamic control of the discharge process by adjusting pump speeds and flow rates to optimize the balance between latent heat recovery and maintaining power exchange, adapting system operation to the changing state of the phase change material
Solution Approach 2:
The patent changes operational parameters such as fluid flow rate, temperature differential, and circulation speed to maintain optimal power exchange during the discharge process, preventing the power exchange from decreasing as the PCM solidifies
4Loss of energy
If exchangers with fins are used, then heat transfer is improved, but storage density is reduced
Solution Approach 1:
The patent applies local quality by concentrating enhanced heat transfer features only where most needed - using fins or extended surfaces on the heat exchanger portions in direct contact with the phase change material, while maintaining simple tank geometry to preserve storage density
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 enhances the efficiency of the charging phase by preventing agglomerate blockages, maintaining power transfer, and reducing storage costs by minimizing the volume of the agglomerate, thus improving the overall performance and reliability of the thermal storage system.
Implementation Method 1
the means for initiating the at least one circulation path are heating means capable of generating heat by the Joule effect
Implementation Method 2
storage using phase change materials which pass from the solid state to the liquid state and vice versa is interesting because the quantity of heat stored per unit volume is greater than that obtained by a sensitive system
Implementation Method 3
the heat transfer takes place by conduction and by natural convection in the liquid phase
Implementation Method 4
the heat transfer takes place by conduction and by natural convection in the liquid phase
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
Device for storing heat in the form of latent heat comprising a reservoir (102) containing a phase-change material, two heat exchangers (104, 106) arranged outside the reservoir (102), the phase-change material being inside the reservoir, at least at the start of a phase change, partly in a solid phase forming an agglomerate (MCPS) situated in the bottom of the reservoir (2), said device comprising: - means (122) that create a circulation path in-between the agglomerate (MCPS) and the reservoir (102) so as to cause a circulation of liquid phase-change material between the agglomerate (MCPS) and a wall of the reservoir (102), and - means (124) that cause the volume of agglomerate (MCPS) to break up and produce chips of phase-change material to form a solid-liquid mixture circulating toward the heat exchangers.