Heat Receiver Tube With Infrared-Reflective Glass To Reduce Thermal Loss

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Solution Overview

Problem

Existing heat receiver tubes with glass encapsulation suffer from significant thermal losses due to infrared radiation, which are not adequately addressed by current designs.

Innovation Solution

A heat receiver tube with a glass tube encapsulation featuring an infrared light reflective coating comprising tin oxide (indium tin oxide) and an additional layer of Al2O3 or SiO2, applied to the inner surface to reflect infrared radiation back to the core tube, reducing thermal losses while maintaining transparency for solar radiation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the infrared light reflective coating is applied to the glass tube, then infrared radiation reflection is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveinfrared radiation thermal lossVSAvoidmanufacturing complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent specifies particular compositional parameters for the transparent conducting coating (tin oxide and indium) and provides a manufacturing method that controls the deposition process. By defining specific material composition ranges and deposition conditions, the patent simplifies the manufacturing process while achieving the desired infrared reflection performance.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If the transparent conducting coating comprises tin oxide and indium, then infrared light reflection is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveinfrared radiation thermal lossVSAvoidcoating composition precision
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The patent defines specific compositional parameters for the transparent conducting coating, including the use of tin oxide and indium in particular proportions. These parameter specifications provide clear manufacturing targets that simplify quality control while achieving optimal infrared reflection performance.

Inventive Principle:
Principle #35Parameter changes

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 effectively reduces thermal losses by 20-60% through selective reflection of infrared radiation, optimizing energy absorption and conversion efficiency in solar power plants using parabolic trough collectors.

Implementation Method 1

the infrared light reflective coating comprises a transparent conducting coating, the transparent conducting coating comprises tin oxide and the tin oxide comprises indium; and an additional layer comprising Al2O3 or SiO2 covers the infrared light reflective coating. The glass tube of the heat receiver tube can be manufactured with following steps: The method comprises following steps: a) providing a glass tube and b) attaching the infrared light reflective coating onto an inner surface of the glass tube.

Methodology Applied
Scientific EffectInfrared radiation reflection: Reflection

Implementation Method 2

The core tube comprises a core tube surface with a solar energy absorptive coating for absorbing solar absorption radiation of the sunlight.

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

Implementation Method 3

The glass tube, which is transparent for the sunlight, is arranged coaxially around an inner, central stainless tube of the heat receiver tube.

Methodology Applied
Scientific EffectLight transmission: Light

Data Source

PatentEP2739581B1Heat receiver tube with a glass tube with infrared light reflective coating, method for manufacturing the glass tube, parabolic trough collector with the heat receiver tube and use of the parabolic trough collector
Publication Date: 2020.04.29 SIEMENS CONCENTRATED SOLAR POWER
  • EP2739581B1 patent drawingFigure 1~2

AI summary

A glass tube with a glass tube wall is provided, wherein an inner surface of the glass tube wall comprises at least partially at least one infrared light reflective coating. Moreover a method for manufacturing the glass tube is provided. The method comprises following steps: a) providing a glass tube and b) Attaching the infrared light reflective coating onto an inner surface of the glass tube. Additionally a heat receiver tube for absorbing solar energy and for transferring absorbed solar energy to a heat transfer fluid, which can be located inside a core tube of the heat receiver tube, is provided. The core tube comprises a core tube surface with a solar energy absorptive coating for absorbing solar absorption radiation of the sunlight. The core tube is enveloped by an encapsulation with the glass tube with the infrared light reflective coating. The core tube surface and the encapsulation are arranged in a distance between the core tube surface and the inner surface of the encapsulation wall with the infrared reflective surface such, that the solar absorption radiation can penetrate the encapsulation with the infrared light reflective coating and can impinge the solar energy absorptive coating. IR radiation emitted from core tube surface reflects back to the core tube and hence reduces energy losses. A parabolic trough collector is provided with at least one heat receiver tube, which is arranged in a focal line of a parabolic mirror, too. The parabolic trough collector is used in a solar power plant for converting solar energy into electrical energy.