Segmented Heat Storage Tank for Uniform Thermal Stratification

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Thermocline heat storage tanks face challenges with thermal ratcheting and inhomogeneities, leading to non-uniform temperature distribution and reduced efficiency in maintaining constant temperature levels during charging and discharging phases.

Innovation Solution

A heat storage tank design featuring a solid matrix with multiple stages separated by layers of liquid coolant, allowing for natural convection to homogenize temperatures and maintain a uniform thermal piston, reducing thermal ratcheting and enhancing temperature stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single tank with solid matrix and liquid heat transfer fluid is used for thermocline storage, then the number of components is reduced and control is simplified, but thermal stratification becomes inhomogeneous and temperature distribution becomes non-uniform

Engineering Contradiction:

Improvenumber of componentsVSAvoidthermal stratification uniformity

Core Design Contradiction:

Device complexityVSStability of the object's composition

Solution Approach 1:

The tank is divided into multiple compartments by horizontal partitions, with each compartment containing a solid matrix bed. This segmentation allows independent thermal management in each compartment while maintaining overall system simplicity, resolving the contradiction between reduced component complexity and improved thermal stratification uniformity

Inventive Principle:

Principle #1Segmentation

2Use of energy by moving object

If high fluid velocity is used during charging and discharging phases, then heat transfer efficiency is improved, but thermal ratcheting increases and causes mechanical stress and inhomogeneities

Engineering Contradiction:

Improveheat transfer efficiencyVSAvoidmechanical stress from thermal ratcheting

Core Design Contradiction:

Use of energy by moving objectVSStress or pressure

Solution Approach 1:

By segmenting the tank into multiple compartments, the fluid velocity in each compartment can be controlled independently at lower levels, reducing thermal ratcheting and mechanical stress while maintaining overall heat transfer efficiency through the distributed compartment structure

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each compartment can have optimized local flow characteristics and solid matrix properties tailored to minimize thermal ratcheting effects, while the overall system maintains efficient heat transfer through the distributed compartment arrangement

Inventive Principle:

Principle #3Local quality

3Strength

If the tank geometry has large diameter and low height ratio, then mechanical strength is improved and thermal ratcheting is reduced, but heat transfer fluid distribution becomes inhomogeneous and thermal piston uniformity deteriorates

Engineering Contradiction:

Improvemechanical strengthVSAvoidthermal piston uniformity

Core Design Contradiction:

StrengthVSStability of the object's composition

Solution Approach 1:

The tank is divided into multiple compartments with optimized individual geometry ratios. Each compartment can have appropriate height-to-diameter ratios for uniform thermal piston, while the overall tank maintains mechanical strength through the distributed compartment structure and reduced individual compartment dimensions

Inventive Principle:

Principle #1Segmentation

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 design achieves stable and uniform temperature distribution across the tank, improving the duration and volume of the isothermal zone, reducing mechanical stress, and maintaining constant temperature levels during operation.

Implementation Method 1

separated by a layer of liquid coolant in which natural convection movements appear in the event of temperature inhomogeneity in a transverse plane. These movements of natural convection ensure a homogenization of the temperature

Methodology Applied

Scientific EffectNatural convection: Free Convection

Implementation Method 2

the said solid thermal storage elements are distributed in at least two superimposed beds along the longitudinal axis, separated by a layer of heat transfer liquid, the heat transfer liquid being able to circulate between the first longitudinal end and the second longitudinal end

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 3

Heat storage can typically be achieved either as sensible energy (by varying the temperature level of a solid or liquid storage material)

Methodology Applied

Scientific EffectSensible heat storage: Heating

Data Source

PatentEP2847535B1Heat storage tank with improved thermal stratification

Publication Date: 2017.03.01 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES

AI summary

A heat storage tank comprising an envelope (2) with a longitudinal axis (X) filled with a heat transfer liquid and solid heat storage elements, a first longitudinal end fitted with first means (10) for collecting and supplying a liquid at a first temperature and a second longitudinal end provided with second means (12) for collecting and supplying a liquid at a second temperature, in which said solid heat storage elements are distributed across three beds (TH1, TH2 and TH3) superposed along the longitudinal axis (X), separated by a layer of liquid (L1, L2 and L3), the heat transfer liquid being capable of flowing from the first longitudinal end to the second longitudinal end.