Radiative Cooling Device Silver Aluminum Reflective Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing radiative cooling devices face challenges in effectively cooling targets while minimizing costs, as they either suffer from high manufacturing complexity or require expensive materials like silver to achieve efficient cooling.
Innovation Solution
A radiative cooling device is designed with a light reflective layer comprising a first layer of silver or silver alloy, a second layer of aluminum or aluminum alloy, and an anti-alloying transparent layer, stacked in a specific order to reduce the amount of silver used and enhance cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a photon bandgap layer is provided as a multilayered assembly of titanium dioxide and magnesium fluoride layers, then light reflection performance is improved, but manufacturing complexity increases and cost reduction becomes difficult
Solution Approach 1:
The patent extracts and removes the complex photon bandgap layer (multilayered assembly of TiO2 and MgF2) from the light reflective layer structure. Instead, it uses a simple single-layer metal layer made of aluminum or aluminum alloy, thereby eliminating manufacturing complexity while maintaining the essential light reflection function through the metallic material's inherent properties.
Solution Approach 2:
The patent changes the material parameter from complex dielectric multilayers (TiO2/MgF2) to a simple metal material (aluminum or aluminum alloy). This parameter change simplifies the structure from multiple layers requiring precise thickness control to a single layer that can be deposited more easily, reducing manufacturing complexity while achieving comparable light reflection performance.
2Quantity of substance
If aluminum is used as the metal layer material, then cost is reduced, but light absorption increases causing heating of the cooling target
Solution Approach 1:
The patent changes the material parameter from silver (high reflectivity, high cost) to aluminum or aluminum alloy (lower reflectivity, lower cost). This parameter change accepts increased light absorption as a trade-off for significant cost reduction, making the radiative cooling device economically viable while still achieving cooling functionality.
Solution Approach 2:
The patent adopts a cheaper metal material (aluminum) that may have shorter operational lifespan or degraded performance compared to silver, but provides sufficient cooling function at a much lower cost. This aligns with the principle of using cost-effective materials that fulfill the basic functional requirements without requiring premium materials.
3Reliability
If silver is used as the metal layer material, then light reflection performance is improved, but cost increases
Solution Approach 1:
The patent extracts and removes silver from the light reflective layer structure, replacing it with aluminum or aluminum alloy. This elimination of the expensive material (silver) directly reduces cost while the aluminum material provides sufficient light reflection performance for the radiative cooling application, achieving a balance between performance and cost.
Solution Approach 2:
The patent substitutes expensive silver with cheaper aluminum material, accepting that the performance may not be identical but is sufficient for the application. This material substitution directly addresses the cost issue while maintaining the essential light reflection function needed for radiative cooling.
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 configuration allows for effective cooling of targets while reducing the cost of the light reflective layer, maintaining the cooling effect over an extended period by preventing alloying between silver and aluminum.
Implementation Method 1
infrared light (radiation) radiated from the radiative surface of the infrared radiative layer is transmitted through the atmospheric window
Implementation Method 2
infrared light (radiation) radiated from the radiative surface of the infrared radiative layer
Implementation Method 3
the light reflective layer reflects the light (visible light, ultraviolet light, infrared light) transmitted through the infrared radiative layer from the radiative surface
Implementation Method 4
an anti-alloying transparent layer for preventing alloying between silver and aluminum
Data Source
AI summary
A radiative cooling device in which an infrared radiative layer for radiating infrared light from a radiative surface and a light reflective layer disposed on a side opposite the radiative surface of the infrared radiative layer are provided in a mutually stacked state. The light reflective layer includes a first layer made of silver or silver alloy, a second layer made of aluminum or aluminum alloy and an anti-alloying transparent layer for preventing alloying between silver and aluminum are stacked in the order of the first layer, the anti-alloying transparent layer and the second layer with the first layer closest to the infrared radiative layer.