A double-sided radiative cooling architecture with a record local cooling power density of 270 W/m2

2021 ◽  
Author(s):  
Lyu Zhou ◽  
Haomin Song ◽  
Nan Zhang ◽  
Jacob Rada ◽  
Matthew Signer ◽  
...  
Keyword(s):  
Power Density ◽  
Cooling Power ◽  
Radiative Cooling ◽  
Local Cooling

scholarly journals High-Performance Multilayer Radiative Cooling Films Designed with Flexible Hybrid Optimization Strategy

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2885
Author(s):  
Peng You ◽  
Xiong Li ◽  
Yijia Huang ◽  
Xiaoliang Ma ◽  
Mingbo Pu ◽  
...  
Keyword(s):  
Power Density ◽  
High Performance ◽  
Silver Film ◽  
Hybrid Optimization ◽  
Electromagnetic Properties ◽  
Cooling Power ◽  
Radiative Cooling ◽  
Optimization Strategy ◽  
Special Significance ◽  
Traditional Design

Despite their great potential for energy-saving applications, it is still challenging to design passive radiative cooling (RC) materials with simultaneous high performance and simple structures based on traditional design philosophy. To solve the contradiction between optimization speed and corresponding performance, we present a flexible hybrid optimization strategy based on a genetic algorithm (GA) in conjunction with the transfer matrix method and introducing the calculation of radiative cooling power density in the evaluation function of the GA. As a demonstration, an optimized coating with 1.5-μm-overlapping MgF2 and Si3N4 layers on top of a silver film was numerically designed. Based on a detailed analysis of the material’s electromagnetic properties and cooling performance, this coating achieved a radiative cooling power density of 62 W/m2 and a temperature reduction of 6.8 °C at an ambient temperature of 300 K. Our optimization strategy may have special significance in the design of high-performance RC materials or other multi-spectral engineering materials with simple structures.

High cooling power density SiGe/Si micro-coolers

2001 ◽  
Vol 37 (2) ◽  
pp. 126 ◽  
Author(s):  
X. Fan ◽  
G. Zeng ◽  
E. Croke ◽  
C. LaBounty ◽  
C.C. Ahn ◽  
...  
Keyword(s):  
Power Density ◽  
Cooling Power

scholarly journals The Application of Passive Radiative Cooling in Greenhouses

2019 ◽  
Vol 11 (23) ◽  
pp. 6703 ◽  
Author(s):  
Chia-Hsin Liu ◽  
Chyung Ay ◽  
Chun-Yu Tsai ◽  
Maw-Tien Lee
Keyword(s):  
Convection Heat Transfer ◽  
Cooling Power ◽  
Radiative Cooling ◽  
Natural Convection Heat Transfer ◽  
Convection Heat ◽  
Monolayer Film ◽  
Cooling Method ◽  
The World ◽  
Oxide Particles ◽  
Reducing Energy

At present, greenhouses are used to grow a variety of crops around the world. However, with the change of climate, the increasingly harsh weather makes it more and more disadvantageous for people to work inside, and plants are difficult to grow. Previous research has illustrated that radiative cooling can be realized by using certain nonmetal oxide particles created for emission in an infrared atmospheric transparency window, which is an environmentally friendly cooling method due to reducing energy consumption. Polyethylene (PE)-based formulations with a UV stabilizer and nonmetal oxide particles (NOP) were first granulated and then formed a monolayer film by co-injection molding. The experimental results show that due to passive radiative cooling, under the environmental conditions of 35 °C, and only considering the natural convection heat transfer, the net cooling power of the greenhouse film developed in this study is 28 W·m−2 higher than that of the conventional PE film. The temperature inside the simulated greenhouse cladded with the new greenhouse covering was on average 2.2 °C less than that of the greenhouse with the conventional PE film.

DESIGN AND ANALYSIS OF THERMOACOUSTIC REFRIGERATOR

2013 ◽  
Vol 21 (01) ◽  
pp. 1350001 ◽  
Author(s):  
B. G. PRASHANTHA ◽  
M. S. GOVINDE GOWDA ◽  
S. SEETHARAMU ◽  
G. S. V. L. NARASIMHAM
Keyword(s):  
Boundary Layer ◽  
Power Density ◽  
Gas Pressure ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Boundary Layer Approximation ◽  
Resonator Design ◽  
Quarter Wavelength ◽  
Calculation Results ◽  
Thermoacoustic Refrigerator

This paper deals with the design and analysis of a quarter-wavelength, 10 W capacity, thermoacoustic refrigerator using short stack boundary layer approximation assumptions. The effect of operating frequency on the performance of the refrigerator is studied using dimensional normalization technique. The variation of stack diameter with average gas pressure and cooling power is discussed. The resonator optimization is discussed and the calculation results show a 9% improvement in the coefficient of performance and 201% improvement in power density for the optimized quarter-wavelength resonator compared to published optimization studies. The optimized resonator design is tested with DeltaEC software and the results show better performance compared to past established resonator designs.

Simulation of chip-size electrocaloric refrigerator with high cooling-power density

2013 ◽  
Vol 102 (11) ◽  
pp. 112901 ◽  
Author(s):  
Haiming Gu ◽  
Brent Craven ◽  
Xiaoshi Qian ◽  
Xinyu Li ◽  
Ailan Cheng ◽  
...  
Keyword(s):  
Power Density ◽  
Cooling Power ◽  
Chip Size

scholarly journals Integration of daytime radiative cooling and solar heating for year-round energy saving in buildings

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiuqiang Li ◽  
Bowen Sun ◽  
Chenxi Sui ◽  
Ankita Nandi ◽  
Haoming Fang ◽  
...  
Keyword(s):  
United States ◽  
Energy Consumption ◽  
Power Density ◽  
Thermal Contact ◽  
Building Energy ◽  
The United States ◽  
Thermal Contact Conductance ◽  
Cooling Power ◽  
Dual Mode ◽  
Heating And Cooling

AbstractThe heating and cooling energy consumption of buildings accounts for about 15% of national total energy consumption in the United States. In response to this challenge, many promising technologies with minimum carbon footprint have been proposed. However, most of the approaches are static and monofunctional, which can only reduce building energy consumption in certain conditions and climate zones. Here, we demonstrate a dual-mode device with electrostatically-controlled thermal contact conductance, which can achieve up to 71.6 W/m2 of cooling power density and up to 643.4 W/m2 of heating power density (over 93% of solar energy utilized) because of the suppression of thermal contact resistance and the engineering of surface morphology and optical property. Building energy simulation shows our dual-mode device, if widely deployed in the United States, can save 19.2% heating and cooling energy, which is 1.7 times higher than cooling-only and 2.2 times higher than heating-only approaches.

Modeling of Near-Field Concentrated Solar Thermophotovoltaic Microsystem

2014 ◽  
Author(s):  
Mahmoud Elzouka ◽  
Mukesh Kulsreshath ◽  
Sidy Ndao
Keyword(s):  
Power Density ◽  
Output Power ◽  
Conversion Efficiency ◽  
Near Field ◽  
Separation Distance ◽  
Heat Radiation ◽  
Cooling Power ◽  
Emitter Temperature ◽  
Pv Cell ◽  
Field Radiation

Modeling of a near-field concentrated solar thermophotovoltaic (STPV) microsystem is carried out to investigate the use of STPV-based solid-state energy conversion as a high power density MEMS power generator. Near-field radiation can be realized between two closely separated surfaces (i.e. order of radiation wavelength), resulting in the enhancement of the heat radiation flux orders of magnitudes higher than the blackbody limit, consequently increasing cell output power density. The Near-field STPV model consists of an absorber/emitter model used to estimate the net power absorbed from solar irradiance, a near-field radiation transfer model to evaluate the power tunneled from the emitter to the PV cell at different separation distances, and a PV cell model to determine the photocurrent generated due to thermal radiation absorbed. Results reveal that decreasing separation distance between the emitter and the PV cell increases the absorber/emitter thermal efficiency, increases conversion efficiency, and the power density (×100 far-field). The results also predict increase in cooling power requirement as the separation distance is decreased, which may be a limiting design parameter for near-field STPV microsystems. Based on the model, an overall conversion efficiency of 17% at a separation distance of 10 nm and emitter temperature of 2000 K with solar concentration 6000 sun can be reached; this corresponds to an output power density of 9×105 W/m2.

Flexible microfluidic electrocaloric cooling capillary tube with giant specific device cooling power density

Joule ◽  
2022 ◽  
Author(s):  
Heng Cui ◽  
Quan Zhang ◽  
Yiwen Bo ◽  
Peijia Bai ◽  
Mengyan Wang ◽  
...  
Keyword(s):  
Power Density ◽  
Capillary Tube ◽  
Cooling Power ◽  
Specific Device
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