Temperature-dependent dual-mode thermal management device with net zero energy for year-round energy saving

Abstract

Reducing needs for heating and cooling from fossil energy is one of the biggest challenges, which demand accounts for almost half of global energy consumption, consequently resulting in complicated climatic and environmental issues. Herein, we demonstrate a high-performance, intelligently auto-switched and zero-energy dual-mode radiative thermal management device. By perceiving temperature to spontaneously modulate electromagnetic characteristics itself, the device achieves ~859.8 W m−2 of average heating power (∼91% of solar-thermal conversion efficiency) in cold and ~126.0 W m−2 of average cooling power in hot, without any external energy consumption during the whole process. Such a scalable, cost-effective device could realize two-way temperature control around comfortable temperature zone of human living. A practical demonstration shows that the temperature fluctuation is reduced by ~21 K, compared with copper plate. Numerical prediction indicates that this real zero-energy dual-mode thermal management device has a huge potential for year-round energy saving around the world and provides a feasible solution to realize the goal of Net Zero Carbon 2050.

Passive Daytime Radiative Cooling of Silica Aerogels

“…The working principle of PRC is emitting heat into the cold space by radiation in the range of 8–13 µm, in which the heat absorption by the atmosphere is negligible. Therefore, to obtain daytime PRC, high solar reflectance is also required [ 21 , 22 , 23 , 24 , 25 ]. Consequently, silica aerogels must also be excellent PRC materials, and when used in outdoor environments, their PRC ability may outperform their thermal insulation properties.…”

Recent progress in organic-based radiative cooling materials: fabrication methods and thermal management properties

“…10f and g). 135 The UV-Vis-IR absorptivity/emissivity spectrum of the device in heating (an aluminum plate coated with nano-chromium oxide powders) and cooling (dioctyl phthalate (DOP)-mod-ified poly(4-methyl-1-pentene) (PMP) encapsulating rutile titanium dioxide nanoparticles) modes is close to the ideal spectrum (Fig. 10h).…”

In Situ Mineralizing Spinning of Strong and Tough Silk Fibers for Optical Waveguides

“…As corroborated by finite difference time domain (FDTD) simulation, the small CaCO 3 NCs are capable of redirecting incident light (Figure S13). 40 We measured the light propagation losses of the fibers by focusing the laser light on the fiber tip and analyzing the images of light propagated inside the fiber obtained with a CCD camera (Figure 5a). The light loss is increased with the fiber elongating (Figure 5b).…”