THERMAL BEHAVIOR OF SERIES OF VAULTED AND FLAT ROOFS EXPOSED TO WIND FLOW AND SOLAR RADIATION

2008 ◽  
Author(s):  
A. Mehdizadeh ◽  
Mahmood Yaghoubi
Keyword(s):  
Solar Radiation ◽  
Thermal Behavior ◽  
Wind Flow ◽  
Flat Roofs

Simplified Thermal Model for Absolute Radiometer Simulation

2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Andre Godoi Lopes ◽  
Ricardo Toshiyuki Irita ◽  
Luiz Angelo Berni ◽  
Waldeir Amaral Vilela ◽  
Graziela da Silva Savonov ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Solar Radiation ◽  
Thermal Behavior ◽  
Solar Irradiance ◽  
Thermal Model ◽  
Thermal Contact ◽  
Total Solar Irradiance ◽  
Space Environment ◽  
Simplified Model ◽  
Material Volume

Abstract The study of solar radiation in space has become something necessary, motivating the launch of radiometers on board satellites dedicated to perform total solar irradiance (TSI) measurements and to build a record of their behavior over the years, thus making these data essential for meteorology and climatology. In this study, we propose a simplified model to understand the thermal behavior of absolute radiometers, which are used in this type of measurement. The model considers the heat transfer among parts through conduction and loss only by radiation since the instrument operates in a space environment. The goal is to understand how each component interferes with sensitivity and response time of the instrument depending on its design, material, volume, and thermal contact. The model was applied to data generated by a prototype for validation.

Wind flow characteristics and their loading effects on flat roofs of low-rise buildings

2002 ◽  
Vol 5 (1) ◽  
pp. 25-48 ◽  
Author(s):  
Zhongshan Zhao ◽  
Partha P. Sarkar ◽  
Kishor C. Mehta ◽  
Fuqiang Wu
Keyword(s):  
Flow Characteristics ◽  
Wind Flow ◽  
Loading Effects ◽  
Flat Roofs

Simulation of a Solar Receiver-Reactor for Hydrogen Production

2009 ◽  
Author(s):  
Martina Neises ◽  
Felix Goehring ◽  
Martin Roeb ◽  
Christian Sattler ◽  
Robert Pitz-Paal
Keyword(s):  
Hydrogen Production ◽  
Solar Radiation ◽  
Thermal Behavior ◽  
Water Splitting ◽  
Solar Furnace ◽  
Small Scale ◽  
Mathematical Tool ◽  
Thermochemical Cycle ◽  
Set Up ◽  
Solar Receiver

The transient thermal behavior of two solar receiver-reactors for hydrogen production has been modeled using Modelica/Dymola. The simulated reactors are dedicated to carry out the same chemical reactions but represent two different development stages of the project HYDROSOL and two different orders of magnitude concerning reactor size and hydrogen production capacity. The process itself is a two step thermochemical cycle, which uses mixed iron-oxides as a redox-system. The iron-oxide is coated on a ceramic substrate, which is placed inside the receiver-reactor and serves on the one hand as an absorber for solar radiation and on the other hand as the reaction zone for the chemical reaction. The process consists of a water splitting step in which hydrogen is produced and a regeneration step during which the used redox-material is being reduced. The reactor is operated between these two reaction conditions in regular intervals with alternating temperature levels of about 800 °C for the water splitting step and 1200 °C for the regeneration step. Because of this highly dynamic process and because of fluctuating solar radiation during the day, a mathematical tool was necessary to model the transient behavior of the reactor for theoretical studies. Two models have been developed for two existing receiver-reactors. One model has been set up to simulate the behavior of a small scale test reactor, which has been built and tested at the solar furnace of DLR in Cologne. Results are very promising and show that the model is able to reflect the thermal behavior of the reactor. Another model has been developed for a 100 kWth pilot reactor which was set up at the Plataforma Solar de Almeri´a in Spain. This model is based on the first model but special geometrical features had to be adapted. With this model temperatures and hydrogen production rates could be predicted.

scholarly journals Thermal behavior evaluation of ventilated roof under variable solar radiation

2016 ◽  
Vol 34 (Special Issue 2) ◽  
pp. S346-S350 ◽  
Author(s):  
Vincenzo Bianco ◽  
Alessandra Diana ◽  
Oronzio Manca ◽  
Sergio Nardini
Keyword(s):  
Solar Radiation ◽  
Thermal Behavior

scholarly journals Short-term forecasting of wind and solar power generation

2021 ◽  
Vol 2131 (5) ◽  
pp. 052050
Author(s):  
V Z Manusov ◽  
S K Khaldarov ◽  
B V Palagushkin
Keyword(s):  
Solar Radiation ◽  
Power Supply ◽  
Power Supply System ◽  
Supply System ◽  
Wind Flow ◽  
Effective Implementation ◽  
Flow Speeds ◽  
Time Of Year ◽  
Short Term Forecasting

Abstract It is important to note that the generated power of renewable sources depends on the natural conditions at a particular geographic point, the level of wind flow speeds and solar radiation. The patterns characterizing these parameters depend on the time of year, locality and are purely probabilistic in nature. Taking into account the above-mentioned conditions for the effective implementation of “green” objects in the power supply system, the purpose of this work is to build forecasting models that are more likely to be able to determine what part of the load can be covered by the power supply system based on wind power and solar installations. This purpose was achieved by constructing and training artificial neural networks with data on the speed of wind flow and solar radiation obtained from real renewable energy facilities. The most significant result is the identification of the necessary forecasting horizon, taking into account the preservation of a relatively good quality of metrics, as well as understanding what additional data is required to improve this quality. The significance of the results obtained lies in the fact that they make it possible to determine what reserve capacity is required to be included in the project.

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