Composite Solar Reflector Sandwich Structure for Low-Weight Precision

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Solution Overview

Problem

Current reflective elements for solar fields, particularly in tower concentration technology, face issues with excessive weight, mechanical weakness, high manufacturing costs, and optical precision due to metal underframes, which limit mirror size and increase costs, and pose safety risks during maintenance.

Innovation Solution

A sandwich-type composite reflective element is manufactured in a single step using a press system with differential temperature control, comprising a reflective sheet, a reinforcement sheet, and a layer of foam, eliminating the need for intermediate support elements and reducing peripheral corrugations, while ensuring high reflectance and optical precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metal underframes with mechanical attachments are used, then structural strength is improved, but weight increases excessively

Engineering Contradiction:
Improvestructural strengthVSAvoidunderframe weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent replaces traditional metal underframes with a composite sandwich structure consisting of a reflective sheet, foam core, and reinforcement sheet. This composite construction provides the necessary structural strength while significantly reducing weight compared to solid metal frames, directly resolving the contradiction between strength and weight.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The reflective sheet in the sandwich structure serves as a thin, lightweight structural element that provides both the reflective function and part of the structural integrity. This thin-film approach eliminates the need for heavy metal support structures while maintaining adequate strength.

Inventive Principle:
Principle #30Flexible shells and thin films

2Stability of the object's composition

If metal underframes with welds and mechanical attachments are used, then structural integrity is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvestructural integrityVSAvoidgeometric precision
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent combines the structural support function and the reflective function into a single integrated sandwich element. The foam core bonded to both the reflective sheet and reinforcement sheet creates a unified structure that eliminates separate support components, reducing the need for high-precision mechanical attachments and welding operations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces mechanical attachment systems (welds, bolts, and mechanical fasteners) with chemical bonding through foam adhesive. This substitution eliminates the need for precise mechanical alignment and drilling operations, significantly reducing manufacturing precision requirements while maintaining structural integrity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Strength

If metal underframes are used, then support for large mirrors is improved, but manufacturing costs increase

Engineering Contradiction:
Improvemirror support capabilityVSAvoidmanufacturing cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The sandwich composite structure provides adequate support for large mirrors through the combined rigidity of the foam core and reinforcement sheet, eliminating the need for expensive metal fabrication. The composite materials are more cost-effective for large-area applications while providing sufficient structural support.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent employs cost-effective materials and a simplified manufacturing process that uses readily available foam and sheet materials. The single-step manufacturing approach reduces labor and equipment costs compared to precision metal fabrication, making large mirror support more economically viable.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Device complexity

If reflective sheets are directly glued to metal structures, then assembly is simplified, but interception loss increases

Engineering Contradiction:
Improveassembly complexityVSAvoidinterception loss
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent merges the adhesive bonding function into the structural core of the sandwich element. The foam material serves simultaneously as the structural core and the bonding medium, eliminating the need for separate adhesive layers and complex multi-step assembly processes. This integration maintains optical precision while simplifying assembly.

Inventive Principle:
Principle #5Merging (Combining)

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 solution results in a self-supporting reflective element with improved weight distribution, reduced manufacturing costs, enhanced optical precision, and increased mirror size, minimizing the risk of breakage during maintenance, thus optimizing solar radiation concentration efficiency.

Implementation Method 1

providing a foamable material in such a way that it completely fills the gap between the first sheet and the reinforcement sheet subjecting them to pressure, the foamable material acquiring its final consistency and forming a substantially rigid layer of foam adhered to both sheets

Methodology Applied
Scientific EffectFoam expansion and curing: Foam

Implementation Method 2

moving the first and second approximation means closer to one another, such that the second approximation means contact the reinforcement sheet and it acquires temperature T2, and providing a foamable material such that it completely fills the gap between the first sheet and the reinforcement sheet subjecting them to pressure

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP2687791B1Method for the production of a reflector element
Publication Date: 2018.12.19 RIOGLASS SOLAR
  • EP2687791B1 patent drawingFigure 1~2
  • EP2687791B1 patent drawingFigure 3A~3C
  • EP2687791B1 patent drawingFigure 4A~4C

AI summary

The present invention relates to a reflective element for solar fields, having a sandwich-type structure, comprising a reflective sheet (1), a reinforcement sheet (2) and a layer of foam (3) arranged between the reflective sheet (1) and the reinforcement sheet (2). The method of manufacturing the reflective element is performed in a press with first and second approximation means, with the following steps: heating the first approximation means to a temperature T1, arranging a reflective sheet on the first approximation means and acquiring the temperature T1, arranging separating means in the periphery of the reflective sheet, arranging a reinforcement sheet in contact with said separating means, heating the second approximation means to a temperature T2 different from T1, moving the approximation means closer to one another, the second approximation means contacting with the reinforcement sheet and acquiring the temperature T2, and providing a foamable material filling the gap between both sheets, subjecting them to pressure, and the foamable material acquiring its final consistency in the form of a substantially rigid layer of foam (3) adhered to both sheets.