Papers by Keyword: Ambient Temperature

Abstract: Considering the dearth and limited supply of potable water for daily consumption globally, developing a desalination technique to produce water sufficient for the need has become imperative. This study examines the improvement of freshwater productivity in a single-slope solar still by incorporating a solar preheating system. The proposed design utilizes solar still distillation to preheat the feed water before it enters the distillation basin. This approach aims to increase the temperature gradient between the water surface and the glass cover, thereby accelerating the evaporation and condensation process. Experimental evaluations were conducted under varying climatic conditions and flow rates, with and without the preheater. We note that the productivity has improved at each flow rate as follows: at a flow rate of 1 L/min, the improvement percentage reached 96% (CLISS:130 g/hr and CLIPSS:170 g/hr), at a flow rate of 2 L/min, the improvement percentage reached 73% (CLISS:180 g/hr and CLIPSS: 220 g/hr), while the improvement percentage at 3 L/min became 61% (CLISS:240 g/hr and CLIPSS:290 g/hr.), and at a flow rate of 4 L/min, it reached 64% (CLISS:280 g/hr. and CLIPSS: 320 g/hr.), and up to a flow rate of 8 liters/minute, the productivity improvement percentage between the two systems reached 31% (CLISS:310 g/hr. and CLIPSS:340 g/hr.). The results showed that the preheated system significantly improved solar thermal performance and daily production, especially during the early morning and late afternoon hours. Compared to a conventional design, the preheated system achieved an overall productivity increase of 25% to 35%.

Abstract: The increase in the temperature of photovoltaic (PV) cells is a critical factor that negatively affects the efficiency of converting solar radiation into electrical energy. This phenomenon not only reduces energy conversion efficiency but also causes damage to PV components, thereby preventing the achievement of the intended energy production goals. Moreover, the heating of PV modules has two significant impacts: first, a reduction in energy efficiency, and second, a decrease in the lifespan of the solar cells. Therefore, projects aimed at producing clean electrical energy using PV solar panels must consider the study of installation sites for PV solar plants and the impact of environmental conditions on panel performance. Given that an increase in PV cell temperature reduces their productivity, this study examines the impact of ambient temperature on the maximum temperature reached by a PV solar panel and analyzes the results. The results show that installing solar panels in harsh environments characterized by high temperatures, such as Ouarzazate in Morocco, can cause these panels to reach critical temperature thresholds of up to 115°C under high solar flux, which can lead to solar system failure and thus the failure of the entire project. In addition, the heating of photovoltaic modules has two major impacts: firstly, energy efficiency is reduced by around 0.44% for every 1°C increase, and overall efficiency is reduced from 16% to less than 10% under extreme conditions; secondly, solar cell life is shortened. Finally, this study highlights the importance of carrying out thorough climatic and environmental assessments before establishing solar photovoltaic power plants. It also highlights the importance of employing high-performance cooling systems or innovative technologies to reduce the impact of heat on photovoltaic panels. This approach is essential to ensure the longevity and efficiency of solar photovoltaic installations, and to achieve our ambitions for sustainable, green energy production.

Abstract: The following work aims to present the numerical solution for a two-dimensional and transient model for heat transfer on storage bins during the period of one year, in which it was supposed that the structure is exposed to ambient temperature, which depends on time. From this hypothesis, it was executed curve fitting of a relation between those quantities, using meteorological data from the city of Pelotas/RS in the year 2021, and the influence that the outside temperature of a bin has over the process of heat transfer that occurs inside the structure was analyzed. Upon executing simulations of heat transfer inside fictitious bins located in this southern Brazilian city, results show that the boundary condition causes considerable variations in grain temperature, which are more intense in points near the bin's surface. Furthermore, it was concluded that containers of least storage show larger variations in inner temperature during the analyzed period when compared to the behavior of bins containing larger sizes.

Abstract: The current population is increasing rapidly and as a consequence a greater number of houses is required, which are consolidated through urbanizations; which modify the hydrological processes, alter the energy exchanges between the sun, the surface and the atmosphere, generating changes in the flows and components of the radiation balance that affect the urban heat island. An alternative to control this heat is to promote a green space through green roofs that improve the urban climate. The present research work studies on prototypes of solid concrete slabs the effect of the plant species Aptenia cordifolia and Sphagneticola trilobata on the temperature and environmental humidity in an extensive green roof. The results indicate that both species have a different behavior, being the species Sphagneticola trilobata the one that presents a better behavior before the higher and lower environmental temperature and higher relative humidity; while the Aptenia cordifolia presents it behaves better before the lower relative humidity.

Abstract: Thermal anomaly Detection prior to earthquake events has been widely confirmed by researchers over the past decade. In this paper, we use robust satellite technique approach (RST) on a collection of six years of MODIS satellite data, representing land surface temperature (LST) images to predict 21st May 2003 Boumerdès Algeria earthquake. The thermal anomalies results were compared with the ambient temperature variation measured in three meteorological stations of Algerian National Office of Meteorology (ONM) (DELLYS-AFIR, TIZI-OUZOU, and DAR-EL-BEIDA). The results confirm the importance of robust satellite technique as an approach highly effective for monitoring the earthquakes.

Abstract: This paper presents the results of an experimental study on the behavior of fly ash-, bottom ash-, and blended fly and bottom ash-based geopolymer concrete (GPC) cured at ambient temperature. Four bathes of GPC were manufactured to investigate the influence of the fly ash-to-bottom ash mass ratio on the microstructure, compressive strength and elastic modulus of GPC. All the results indicate that the mass ratio of fly ash-to-bottom ash significantly affects the microstructure and mechanical properties of GPCs

Abstract: This paper presents the results of an experimental study on the behavior of bottom ash-based geopolymer concrete (GPC) cured at ambient temperature. A total of five bathes of bottom ash-based GPC were manufactured. The influence of the particle size and chemical composition of bottom ash on the compressive strength of GPC was investigated. The results indicate that the investigated parameters significantly affect the 28-day compressive strength of bottom ash-based GPCs. It is also found that the strength gain of ambiently-cured coal ash-based GPCs continues beyond the concrete age of 28 days.

Abstract: Conditions such as the execution of repair works and ambient environment can affect the protective performance of surface coating material for concrete structures, and they are important in terms of exhibiting a long-term repair effect. This paper presents a fundamental study on the influence of film thickness and ambient temperature to the protective performance of surface coating material: oxygen, moisture vapor and chloride ion permeability. It was confirmed that as film thickness and ambient temperature increased, oxygen, moisture vapor and chloride ion permeation rates decreased and increased, respectively. Test results showed a good agreement with the behavior of polymer molecule membrane.

Abstract: This paper presents the results of measurements of the operation of a photovoltaic system, connected to the power grid of the building. Parallel the intensity of solar radiation and the ambient temperature in the location of the installation was recorded in different weather conditions on selected days throughout the year. For the combined results the analysis of correlation in terms of yields of individual exemplary photovoltaic installation was conducted.

Abstract: As a renewable energy and clean energy source, solar power has great development potential. This paper presents the potential of solar radiation and ambient temperature characteristics can be used as alternative energy. All data collected using Davis Vantage Pro2 Weather Station at Centre of Engineering for Renewable Energy (CERE) in Kangar, Perlis. All data consist of daily and monthly average was analyzed. The result shows the average solar radiation and ambient temperature is high in the middle of the year 2013 which is from April to September. These results provide useful information for the design of solar energy system in order to plan the productive system.