Vacuum Solar Panel Radiative Screen for Getter-Free Absorbers

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Solution Overview

Problem

Current double-sided vacuum solar panels face issues such as the getter film altering the absorption and reflection properties of the heat absorbers, high production costs due to the use of copper for low infrared emissivity, and challenges in welding the pipe and absorber components.

Innovation Solution

A double-sided vacuum solar panel design featuring a getter pump within a box-like element that does not interfere with the absorber coatings, using aluminum for the thermo-vector fluid pipe to reduce costs and radiation losses, and incorporating flat contact surfaces for improved heat transfer and welding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thin getter film is arranged on the absorber surface under the selective absorption coating, then vacuum maintenance is improved, but the visible light absorption and infrared emission properties of the coating are degraded

Engineering Contradiction:
Improvevacuum maintenanceVSAvoidvisible light absorption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The getter pump is extracted from the absorber surface location and placed in a separate box-like element positioned at the periphery of the vacuum envelope. This separation removes the harmful getter film from the absorber surface, preserving the selective coating's optical properties while maintaining vacuum functionality through the side wall placement.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The box-like element acts as an intermediary structure that houses the getter pump away from the absorber. This intermediate positioning allows the getter to maintain vacuum without its film contaminating the absorber surface, mediating between vacuum maintenance requirements and optical performance needs.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If copper is used for the pipe to achieve low infrared emissivity, then thermal energy losses by pipe irradiation are reduced, but production costs and maximum operating pressure limitations increase

Engineering Contradiction:
Improvethermal energy losses by pipe irradiationVSAvoidproduction costs
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

Instead of using expensive copper pipe, the invention uses an aluminum pipe复制 (copy) of the thermal function, combined with a reflective coating to replicate the low-emissivity surface property. The reflective coating on aluminum provides similar infrared radiation control to copper but at lower material cost.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The material parameter of the pipe is changed from copper to aluminum, and the surface property is modified by adding a reflective coating. This parameter change maintains the low infrared emissivity function while reducing material cost and removing pressure limitations.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If laser welding is used to join the pipe and absorber, then welding precision is improved, but the contact surface area requirement becomes very small and positioning difficulty increases

Engineering Contradiction:
Improvewelding precisionVSAvoidpositioning difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

Flat contact surfaces are prepared in advance on both the pipe and absorber before welding. This preliminary action creates a larger, more tolerant contact area that simplifies positioning and alignment during assembly, while still allowing precise laser welding to be performed on the prepared surfaces.

Inventive Principle:
Principle #10Preliminary action

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 design maintains optimal absorption and reflection properties, reduces thermal energy losses, and facilitates cost-effective production while enhancing heat transfer and welding efficiency.

Implementation Method 1

heat absorbers placed inside said envelope to absorb solar radiation and to convert it into thermal energy

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Implementation Method 2

the infrared emissivity coefficient of a surface provided with a selective absorption coating depends on the constituent material of said surface

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 3

Getter pumps are also positioned in vacuum panels, to absorb by a chemical effect any gas residues still present in the envelope

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 4

The thermal energy collected by the heat absorber is transmitted via said weld to the pipe by conduction

Methodology Applied
Scientific EffectConduction (thermal): Conduction (thermal)

Data Source

PatentEP2229561B1Vacuum solar thermal panel with radiative screen
Publication Date: 2011.12.14 TVP SOLAR
  • EP2229561B1 patent drawingFigure 1
  • EP2229561B1 patent drawingFigure 2
  • EP2229561B1 patent drawingFigure 3

AI summary

A double-sided vacuum thermal solar panel comprising a vacuum-tight envelope (30) capable of withstanding atmospheric pressure when evacuated, said envelope (30) comprising a first and a second glass sheet (1, 2) transparent to solar radiation and facing each other, a perimetral frame (3) defining the lateral surface of said envelope (30), said solar panel comprising at least one first heat absorber (11), a second heat absorber (12), a pipe (13) which enters and leaves said envelope (30) by passing between said first and second heat absorber (11, 12), and a box element (10) which surrounds the outer surface of the pipe (13).