Sodium tungsten bronze(Na_(x)WO_(3))-doped near-infrared-shielding bulk glasses for energy-saving applications

Tungsten bronze coatings and films have attracted global attention for their applications in near-infrared(NIR)-shielding windows.However,they are unstable in strong ultraviolet,humid heat,alkaline and/or oxidizing environments and are difficult to be coated on glass surfaces with complex shape.Here,we address these limitations by doping sodium tungsten bronze(Na_(x)WO_(3))into bulk glasses using a simple glass melting method.X-ray diffraction,Raman spectroscopy,X-ray photoelectron spectroscopy,TEM and SEM-EDS characterization confirmed the presence of sodium tungsten bronze(Na_(x)WO_(3))functional units inside the 34SiO_(2)-38B_(2)O_(3)-28NaF glass matrix.Because the functional units are well protected by the glass matrix,the fabricated glasses are stable under hot,humid,oxidizing conditions,as well as under ambient conditions,with no change after 360 days.The NIR-shielding performance of these glasses can be adjusted to as high as 100%by varying WO_(x)concentration(2-8 mol%)and quenching temperature(1000-1400℃).With a content of 6 mol%WO_(x)and a quenching temperature of 1000℃,the bulk glass shows 63%transmission of visible light and only 11%transmission of NIR light at 1100 nm.Thermal insulation experiments show that the NIR-shielding performance of the glasses are far superior to commercial soda lime window glass or indium-doped tin oxide(ITO)glass,and comparable to cesium tungsten bronze coated glass.The novel bulk glasses have higher stability,simpler processing,and can be easily made into complex shapes,making them excellent alternative materials for energy-saving glasses.

Realization of energy-saving glass using photonic crystals

This work successfully developed an energy- saving glass with wavelength selectivity. The glass is composed of a SiO2 substrate and two layers of three- dimensional photonic crystals. Each crystal is composed of identical and transparent polystyrene spheres after their self-assembling. The glass then possesses dual photonic band gaps in the near-infrared region to suppress penetration of thermal radiation. Experimental results show that the energy-saving glass decreases temperature increment in a mini-house. Moreover, the temperature after thermal equilibrium is lower than that inside a counterpart using ordinary glass.

Research on Landscape Energy-Saving Integrated Water Curtain System

Aiming at the serious heat and cold loss of the building glass curtain wall in the field of amusement and tourism,and the need to meet the landscape requirements of the building facade,this paper put forward the idea of integrating the shading and consumption reduction of glass curtain wall with the landscape requirements,that is,the water curtain was set outside the glass curtain wall to form a landscape energy-saving integrated water curtain wall system,while meeting the needs of landscape and shading.By establishing the numerical calculation model of the system,the corresponding relationship between the thickness of water film and the weakening of solar radiation intensity was revealed,as well as the influence of wind speed and wind direction on the nozzle exit angle and velocity selection;and the synergistic law of air flow rate and air temperature drop amplitude.The results showed that the water film thickness at 3-4 cm can reduce the solar radiation by 65%-80%.The temperature of the air layer between the water film and the curtain wall decreased as the air flow rate decreased,when the thickness of water film was 2 cm and the air velocity was 0.5-1.5 m/s,the air temperature dropped to 2.47-3.6°C.Finally,through the analysis of the actual project-ICE World&WATER Park,the system can reduce 66.8%of solar radiation,and reduce the air layer temperature by 3.9°C.