Parabolic Trough Absorber Tube Support for Thermal Expansion

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Solution Overview

Problem

Existing parabolic trough collector systems face challenges with complex, costly, and maintenance-intensive absorber tube connections, leading to pressure drops, heat losses, and increased investment costs due to the need for flexible connections and rotary length compensation devices to accommodate absorber tube expansion and pivoting.

Innovation Solution

A parabolic trough collector module design featuring a pivotably mounted parabolic reflector with a support device that includes a linear guide for the absorber tube, allowing for unhindered expansion and distributing the tube's weight, eliminating the need for complex connections and compensation devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If flexible absorber pipe connections (ball joint or swivel joint connecting pipes) are used to accommodate absorber tube expansion and pivoting, then the absorber tube can move freely during operation, but the structural complexity and investment costs increase significantly

Engineering Contradiction:
Improveabsorber tube movement capabilityVSAvoidconnecting pipe structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention extracts the absorber tube from the rotating joint mechanism and mounts it directly to the rotating support structure. This eliminates the complex flexible connecting pipes (ball joint or swivel joint) while maintaining the absorber tube's ability to move with the reflector during pivoting operations.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention merges the absorber tube mounting function with the rotating support structure itself. Instead of using separate flexible connecting pipes, the absorber tube is integrated directly onto the rotating support, combining the support and connection functions into a single simplified structure.

Inventive Principle:
Principle #5Merging (Combining)

2Adaptability or versatility

If flexible absorber pipe connections are used to accommodate absorber tube expansion and pivoting, then the absorber tube can move freely during operation, but maintenance requirements and operational costs increase

Engineering Contradiction:
Improveabsorber tube movement capabilityVSAvoidconnecting pipe maintenance
Core Design Contradiction:
Adaptability or versatilityVSEase of repair

Solution Approach 1:

The invention removes the flexible connecting pipes (ball joint or swivel joint) from the system, eliminating the maintenance-intensive components that require regular inspection, lubrication, and replacement due to wear from flexible movement.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces expensive, maintenance-intensive flexible connecting pipes with a simpler, more durable direct mounting structure that has fewer moving parts and lower lifecycle costs, even if the initial structure appears more permanent.

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

3Adaptability or versatility

If flexible absorber pipe connections are used to accommodate absorber tube expansion and pivoting, then the absorber tube can move freely during operation, but pressure drop and heat loss increase

Engineering Contradiction:
Improveabsorber tube movement capabilityVSAvoidheat loss and pressure drop
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The invention extracts the absorber tube from the complex flexible connection system, eliminating the multiple joints and bends in ball joint or swivel joint connecting pipes that cause pressure drop and heat loss, while maintaining necessary movement capability through direct mounting to the rotating support.

Inventive Principle:
Principle #2Taking out (Extraction)

4Adaptability or versatility

If the absorber tube is moved along during pivoting (center of gravity near apex), then the parabolic reflector can be aligned with the sun position, but complex absorber tube holders and rotary length compensation devices are required

Engineering Contradiction:
Improvereflector alignment capabilityVSAvoidabsorber tube holder structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention merges the absorber tube support function with the rotating support structure for the parabolic reflector. The absorber tube is mounted directly to the rotating support, combining the alignment and support functions into a single integrated structure, eliminating separate complex absorber tube holders and rotary length compensation devices.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention removes the complex absorber tube holders and rotary length compensation devices from the system by integrating the absorber tube directly onto the rotating support structure, simplifying the alignment mechanism while maintaining functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

5Strength

If the supporting structure of the parabolic reflector is made load-bearing and stable to absorb high weight forces of the absorber pipe, then the absorber tube can be supported during pivoting, but investment costs significantly increase

Engineering Contradiction:
Improvesupport structure load-bearing capacityVSAvoidsupport structure construction
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention merges the support function into the rotating support structure itself, which is already designed to bear the reflector's weight and provide stable pivoting. This integration eliminates the need for separate load-bearing support structures, reducing overall construction complexity and investment costs while maintaining necessary strength.

Inventive Principle:
Principle #5Merging (Combining)

6Adaptability or versatility

If absorber tube holders are tilted to compensate for axial elongation of the absorber tube, then thermal expansion can be accommodated, but the absorber tube may move out of the focus of the parabolic reflector

Engineering Contradiction:
Improvethermal expansion compensationVSAvoidabsorber tube positioning accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The invention extracts the absorber tube from the tilted holder mechanism, eliminating the compromise between expansion compensation and focus positioning. The absorber tube is mounted directly to the rotating support with proper initial positioning, removing the need for tilt adjustment that causes focus deviation.

Inventive Principle:
Principle #2Taking out (Extraction)

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 simplifies the structural support, reduces investment costs, minimizes heat and pressure losses, and enables a stable, efficient solar thermal power plant operation by maintaining the absorber tube within the focus of the reflector, allowing for longer unit lengths and improved thermal performance.

Implementation Method 1

a parabolic trough reflector (5) with a reflector surface (7) that focuses solar radiation onto the absorber tube (3)

Methodology Applied
Scientific EffectSolar radiation focusing: Focusing

Implementation Method 2

Solar thermal power plants harness sunlight energy to heat a heat transfer medium

Methodology Applied
Scientific EffectSolar energy absorption: Absorption (EM radiation)

Implementation Method 3

the absorber tubes expand due to heat when heated by solar radiation

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4013999B1Parabolic trough collector module, parabolic trough collector module unit, and solar thermal power plant
Publication Date: 2024.11.20 DEUTSCHES ZENTRUM FÜR LUFT UND RAUMFAHRT E V
  • EP4013999B1 patent drawingFigure 1
  • EP4013999B1 patent drawingFigure 2
  • EP4013999B1 patent drawingFigure 3a~3b

AI summary

A parabolic trough collector module (1) comprising: an absorber tube (3) with a central axis (A); a parabolic reflector (5) which focuses solar radiation onto the absorber tube (3) and which comprises a reflector surface (7); and a stand device (9), on which the parabolic reflector (5) is pivotally mounted, the stand device (9) having at least one stand post (9a) and the absorber tube (3) being mounted on the stand post (9a), characterised in that, in the reflector surface (7), the parabolic reflector (5) has a cut-out section (12) running perpendicularly to the longitudinal direction, and a support device (14) extends through the cut-out section (12) and has an absorber tube mount (20) that forms a linear guide, on which mount the absorber tube (3) is slidingly mounted in the longitudinal direction.