Daylighting Dynamic Control by Smart Window with Grating Optical Filter

2021 ◽  
pp. 27-32
Author(s):  
Irina A. Odenbakh
Keyword(s):  
Solar Radiation ◽  
Dynamic Control ◽  
Optical Filter ◽  
Thermal Conditions ◽  
Working Hours ◽  
Time Of Day ◽  
Light Transmittance ◽  
The Sun ◽  
Smart Window ◽  
Solar Radiation Intensity

A smart window with a novel grating optical filter is proposed, which supplies dynamic daily and annual control of window transmission without the use of blinds and similar devices. The filter attenuates direct solar radiation, letting in diffused and reflected radiation, thus creating more comfortable conditions for daylighting, insolation, and sun protection in rooms. A method for calculating the grating filter is changed and numerical modelling is conducted to show the capabilities of the new method of dynamic control of transmission. The optimal geometric parameters of the filter for a single-glazed smart window at a given azimuth of the window orientation are determined. The hourly values of the light transmittance of the filter during daylighting hours are calculated for the 15th day of each month from April to September, and the theoretical angular characteristics of the transmission of the filter, corrected for reflection and absorption, are constructed. The average monthly values of the theoretical and corrected light transmittance of a smart window are obtained, based on the results of calculations every hour compared to the time of day when the azimuths of the Sun and the window are equal. It is shown that the smart window with the built-in grating optical filter provides the minimum transmission at a given time of the day, taking into account the azimuth of the window, the geographic coordinates of the building, the seasonal and daily distribution of the solar radiation intensity on the calculated day of the year, and in the rest of the time, with the most demanded protection from solar radiation, the filter functions within acceptable limits. It is stated that the smart window with the built-in optical filter is most suitable for rooms with a long stay of people during daylight hours that is for office, educational, industrial, etc. rooms, in order to provide comfortable daylighting and the required insolation and thermal conditions during working hours.

A Smart Window for Angular Selective Filtering of Direct Solar Radiation

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Rustam S. Zakirullin
Keyword(s):  
Solar Radiation ◽  
Light Transmission ◽  
Slope Angle ◽  
Optical Filter ◽  
Time Of Day ◽  
Direct Solar Radiation ◽  
Smart Window ◽  
Smart Windows ◽  
Solar Radiation Intensity ◽  
Parallel Strips

Thin-film grating coatings are proposed for smart windows to angular selective filtering of solar radiation. The gratings are formed by absorptive, reflective, or scattering parallel strips (made of chromogenic or other materials) alternating with directionally transmissive strips (untreated surface of pure glass) on two surfaces of the window pane(s). The smart window with grating optical filter has angular selective light transmission and partially or completely blocks the direct solar radiation in a preset angular range and transmits the scattered and reflected radiation without using the daylight redistribution devices. The results of numerical simulation and experimental confirmation of optimum slope angle of the strips on the pane(s), their widths, and relative position on two surfaces to minimize the directional light transmission of the window at the preset date and time of day taking into account orientation of the window to the cardinal, the latitude of the building, and the seasonal and daily distribution of the solar radiation intensity are demonstrated.

Determination of Mars Solar-Belt by Modeling of Solar Radiation Using Artificial Neural Networks

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Tamer Khatib ◽  
Irjuwan Abunajeeb ◽  
Zainab Heneni
Keyword(s):  
Solar Radiation ◽  
Back Propagation ◽  
Photovoltaic System ◽  
Photovoltaic Systems ◽  
The Sun ◽  
Water Ice ◽  
Available Energy ◽  
Feed Forward Back Propagation ◽  
Solar Radiation Intensity ◽  
Artificial Neural

Missions to Mars need a power source, while, one of the most compatible sources for such a purpose is the photovoltaic system. Photovoltaic systems generate power based on the available energy from the Sun, and thus, solar radiation intensity at Mars should be known for design purposes. In this research, the feed-forward back-propagation artificial neural network is developed to predict solar radiation in terms of longitude, latitude, time of the day, temperature, altitude, pressure, amount of dust, and volume mixing ratio of water ice clouds. Data which are used to develop this model are obtained from the Mars Climate Database. The results of the developed method are accurate as compared with other methods whereas the correlation (R2) coefficient for the developed model is 0.97. The developed model then is used to predict mean solar radiation and mean temperature for every location on Mars and then the data are presented on Mars maps in order to determine the best location for harvesting energy from the Sun by photovoltaic systems. According to results, the solar radiation-temperature belt on Mars is found to be between latitudes 20 deg south and 15 deg north.

ATMOSPHERIC REFRACTION AND TEMPERATURE GRADIENT

1962 ◽  
Vol 16 (1) ◽  
pp. 24-31 ◽  
Author(s):  
P.V. Angus-Leppan
Keyword(s):  
Temperature Gradient ◽  
Solar Radiation ◽  
Radiation Intensity ◽  
Time Of Day ◽  
Vertical Temperature Gradient ◽  
Vertical Temperature ◽  
Atmospheric Refraction ◽  
Intensity Measurements ◽  
Solar Radiation Intensity

The coefficient of refraction is far from constant. It varies chiefly because of changes in the vertical temperature gradient of the atmosphere. From measurements of vertical angles between points of known heights, observed angles of refraction can be deduced. By the use of simultaneous meteorological measurements, various methods of calculating refraction are developed. It is necessary to derive a formula representing temperature as a function of height and time of day. Calculated refraction compares accurately with observed, especially when solar radiation intensity measurements are used.

scholarly journals Smart window for angular selective filtering of solar radiation

2019 ◽  
Vol 124 ◽  
pp. 01002
Author(s):  
R. Zakirullin ◽  
I. Odenbakh
Keyword(s):  
Solar Radiation ◽  
Light Transmission ◽  
Slope Angle ◽  
Optical Filter ◽  
Angular Range ◽  
Smart Window ◽  
New Approach ◽  
Direct Radiation ◽  
Daily Change ◽  
Parallel Strips

A new approach to angular selective filtering of the solar radiation without using the sunlight redistribution devices is proposed. Parallel strips of chromogenic materials on two surfaces of the pane(s) form an optical filter having angular selective light transmission. Clarified methods to calculate the optimum slope angle of the strips on the pane(s), their widths and relative position on two surfaces considering the seasonal and daily change in the solar radiation, the location of the building and the window’s azimuth are presented. Such a smart window blocks the direct radiation in a preset angular range and transmits the scattered and reflected radiation that is provides comfortable daylighting indoors.

Experimental Research of Solar Wall in Building Application

2011 ◽  
Vol 128-129 ◽  
pp. 1456-1459
Author(s):  
Lin Qiu ◽  
Yue Zou ◽  
Li Huang ◽  
Geng Ren
Keyword(s):  
Solar Radiation ◽  
Air Temperature ◽  
Sun Exposure ◽  
The Sun ◽  
System Function ◽  
Solar Radiation Intensity ◽  
Reasonable Range ◽  
Solar Wall ◽  
The Relationship ◽  
Wall System

The paper investigated the efficient model of solar wall and the operation modes of solar wall system on buildings application, The construction of efficient solar wall was devised and experiment studied the operation effect. In order to find out the relationship between solar radiation and outlet air temperature, the air temperature change per unit solar radiation intensity (▽) was introduced. Study given: the system function or use of shade structures and architecture integration measures, relative to the building directly by the sun exposure, the surface temperature of building with the efficient solar wall can be achieved a more substantial cooling; the same time the system can be improved through natural convection air-conditioned room air quality will not result in excessive waste of energy. Solar radiation is the decisive factor in the process of heating air. to meet the requirement of indoor heating, the reasonable range of ▽ is 5.63-6.35, the optimum system wind velocity would be 3 m/s-7m/s.

scholarly journals High-Efficiency Responsive Smart Windows Fabricated by Carbon Nanotubes Modified by Liquid Crystalline Polymers

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 440
Author(s):  
Yuan Deng ◽  
Shi-Qin Li ◽  
Qian Yang ◽  
Zhi-Wang Luo ◽  
He-Lou Xie
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Crystalline ◽  
Near Infrared ◽  
High Efficiency ◽  
Polymer Brush ◽  
Light Transmittance ◽  
Smart Window ◽  
Vertical Orientation ◽  
Smart Windows ◽  
Conversion Materials

Smart windows can dynamically and adaptively adjust the light transmittance in non-energy or low-energy ways to maintain a comfortable ambient temperature, which are conducive to efficient use of energy. This work proposes a liquid crystal (LC) smart window with highly efficient near-infrared (NIR) response using carbon nanotubes grafted by biphenyl LC polymer brush (CNT-PDB) as the orientation layer. The resultant CNT-PDB polymer brush can provide the vertical orientation of LC molecules to maintain the initial transparency. At the same time, the smart window shows a rapid response to NIR light, which can quickly adjust the light transmittance to prevent sunlight from entering the room. Different from common doping systems, this method avoids the problem of poor compatibility between the LC host and photothermal conversion materials, which is beneficial for improving the durability of the device.

Thermal comfort analysis of a high-speed train cabin considering the solar radiation effects

2019 ◽  
Vol 29 (8) ◽  
pp. 1101-1117
Author(s):  
Lin Yang ◽  
Xiangdong Li ◽  
Jiyuan Tu
Keyword(s):  
Solar Radiation ◽  
Thermal Comfort ◽  
High Speed ◽  
Radiation Effects ◽  
Numerical Study ◽  
Thermal Conditions ◽  
Long Distance ◽  
High Speed Rail ◽  
Hot Weather ◽  
Cabin Environment

Due to the fast development of high-speed rail (HSR) around the world, high-speed trains (HSTs) are becoming a strong competitor against airliners in terms of long-distance travel. Compared with airliner cabins, HST cabins have much larger window sizes. When the big windows provide better lighting and view of the scenery, they also have significant effects on the thermal conditions in the cabins due to the solar radiation through them. This study presents a numerical study on the solar radiation on the thermal comfort in a typical HST cabin. The effect of solar radiation was discussed in terms of airflow pattern, temperature distribution and thermal comfort indices. Parametric studies with seven different daytime hours were carried out. The effect of using the roller curtain was also studied. The overall cabin air temperature, especially near passengers, was found to have significantly increased by solar radiation. Passengers sitting next to windows were recorded to have an obvious thermal comfort variation at different hours of the day. To improve the passengers’ comfort and reduce energy consumption during hot weather, the use of a curtain could effectively reduce the solar radiation effect in the cabin environment.

Wastewater disinfection by neutral pH photo-Fenton: The role of solar radiation intensity

2016 ◽  
Vol 181 ◽  
pp. 1-6 ◽  
Author(s):  
E. Ortega-Gómez ◽  
M.M. Ballesteros Martín ◽  
B. Esteban García ◽  
J.A. Sánchez Pérez ◽  
P. Fernández Ibáñez
Keyword(s):  
Solar Radiation ◽  
Radiation Intensity ◽  
Neutral Ph ◽  
Solar Radiation Intensity ◽  
Wastewater Disinfection
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