This research carried out on drying kinetics and quality of dried orange slices in three indirect solar dryers with natural convection, to compare the thermal performance of solar dryers, a data acquisition system is used to follow the evolution of climatic variables (temperature, relative humidity, solar radiation). The experimental measurements for several days in April and May show the average temperature does not exceed 19.5 °C, while the average internal temperatures are 40 °C for Dry3 (the third solar dryer), 34 °C for Dry1 (the first solar dryer) and 28 °C for Dry2 (the second solar dryer). While the relative humidity of the outdoor environment varies in the interval [60%, 85%]. For the relative humidity into dryers, it is observed that the values are ranging in the intervals [5%, 35%] for Dry3, [5%, 70%] for Dry1, and [32%, 75%] for Dry2. Based on these obtained climatic conditions, drying the orange slices is carried out. It was found that the orange slices lost 72% of their initial mass after 6 days in the Dry3, after 15 days for Dry1 and after 18 days for Dry2. The study'’s main experiments have shown that a special formulated the third solar dryer is most effective through thermal performance and drying duration, in terms of economic costs, the design of the Dry3 with a single compartment is less expensive than conventional two-compartment solar dryers. So, Dry3 is beneficial and encourages its use by the local producer. • The fabrication of three food solar dryer (natural convection) to reach a simple and cost-effective dryer for use by farmers. • Comparison the effectiveness of three passive solar dryers for food. • Obtention of high thermal performances for relative humidity and temperature inside the dryer. • The result shows that third dryer had a high thermal performance. 

Design, realization and comparison of three passive solar dryers. Orange drying application for the Rabat site (Morocco)

Population growth and urbanization cause developing-country cities to create energy-intensive buildings. Building energy efficiency can be improved through active and passive solar design to reduce energy consumption, increase equipment efficiency, and utilize renewable energy, converting renewable energy into thermal energy or electricity. In this study, passive architecture was evaluated for both urban block and building energy usage. When reliable information and analysis of signs and parameters impacting energy consumption are available, designers and architects can evaluate and passively design a building with higher precision and an accurate picture of its energy consumption in the early stages of the design process. This article compares the location of Baku’s building mass to six climate-related scenarios. Three methodologies are used to determine how much solar energy the models utilize and the difference between annual heating and cooling energy consumption. The structure’s rotation has little effect on the energy utilized in most forms. Only east-west linear designs employ 6 to 4 kWh/m2 of area and are common. Most important is the building’s increased energy consumption, which can take several forms. The building’s westward rotation may be its most important feature. Any westward revolution requires more energy. Building collections together offers many benefits, including the attention designers and investors provide to all places. Having an integrated collection and a sense of community affects inhabitants’ later connections. Dictionary and encyclopedia entries include typology discoveries. These findings will inform future research and investigations. An architect must know a variety of qualities and organizations to define and segregate the environment because architecture relies heavily on the environment. This research involves analyzing the current situation to gain knowledge for future estimations. The present will determine the future.

/pdf/an-analysis-of-urban-block-initiatives-influencing-energy-1yud32wi.pdf

An Analysis of Urban Block Initiatives Influencing Energy Consumption and Solar Energy Absorption

The use of new energy sources, such as geothermal energy, is rapidly expanding worldwide, and it is a viable alternative to fossil fuels. This paper proposes a geothermal power generation system (combined single flash geothermal cycle with transcritical carbon dioxide recovery cycle). To improve system performance, a recuperator is used to recover some of the heat loss. The proposed system simulation is performed in EES software and then validated by previous research. The proposed system is analyzed from the perspective of energy and exergy. The effects of the proposed system separator pressure, carbon dioxide turbine inlet pressure and carbon dioxide condenser outlet temperature on energy efficiency, exergy efficiency and system net power output have been investigated. Findings show that the proposed system in recovery mode has a net power output of 401.40 kW, energy efficiency of 53.6 percent, and exergy efficiency of 46.32 percent, which are significantly higher than the basic mode’s values of 149.9 kW, 2.39 percent, and 12.12 percent, respectively. 

Thermodynamic investigation of a single flash geothermal power plant powered by carbon dioxide transcritical recovery cycle

Renewable energies are the best solutions to reduce CO2 emissions and supply reliable electricity. This study aims to find the best combination of various components considering economic, environmental, and technical factors together. The most important consideration factors are the limitation of using PV panels due to the land constraints and applying CO2 penalties where diesel generators and the grid are generating electricity. Findings show that providing electricity by hybrid systems would be useful even in the well-provided electricity regions by the grid with the least blackouts. The best combination of the proposed components, including PV, bio generator, diesel generator, batteries, and grid for the case study region where the load demand is 890 kWh/day and peak load is 167.2 kW, would be an off-grid hybrid system including PV, bio generator, diesel generator, and battery. The optimization results show an NPC (present value of the costs of investment and operation of a system over its lifetime) of $1.02 million and a COE (the average cost per capital of useful electricity produced by the system) of 0.188 $/kWh. Finally, due to the showing of the effect of different conditions on the optimization results and making the study usable for other circumstances of the case study region, some sensitivity analyses have been carried out.

/pdf/optimal-design-of-hybrid-renewable-systems-including-grid-pv-1lcn5w79.pdf

Optimal Design of Hybrid Renewable Systems, Including Grid, PV, Bio Generator, Diesel Generator, and Battery

Adaptive Meta-Learning Extreme Learning Machine with Golden Eagle Optimization and Logistic Map for Forecasting the Incomplete Data of Solar Irradiance

One of the main approaches for performance improvement of thermal power plants is employing preheating units. Preheating the air or stream in Brayton or Rankine cycles can significantly improve the overall efficiency output power. Solar energy, as an available renewable energy, is an attractive option to be employed as the source of preheating. In the present article, applications of solar energy for preheating air and steam in thermal power plants are reviewed. According to reviews, enhancement in the performance of the systems is under influence of several factors such as the configuration of reference system, operating condition, applied technology etc. Besides performance enhancement of the power plant, integration of solar preheating system can remarkably reduce the fuel consumption and consequently the emission of carbon dioxide. Furthermore, due to the unavailability of the solar energy in nigh and cloudy hours, applying thermal storage units can enhance the reliability of the system and increase contribution of solar energy in the output of the system. 

A review on applications of solar energy for preheating in power plants

One of the main approaches for performance improvement of thermal power plants is employing preheating units. Preheating the air or stream in Brayton or Rankine cycles can significantly improve the overall efficiency output power. Solar energy, as an available renewable energy, is an attractive option to be employed as the source of preheating. In the present article, applications of solar energy for preheating air and steam in thermal power plants are reviewed. According to reviews, enhancement in the performance of the systems is under influence of several factors such as the configuration of reference system, operating condition, applied technology etc. Besides performance enhancement of the power plant, integration of solar preheating system can remarkably reduce the fuel consumption and consequently the emission of carbon dioxide. Furthermore, due to the unavailability of the solar energy in nigh and cloudy hours, applying thermal storage units can enhance the reliability of the system and increase contribution of solar energy in the output of the system.

This investigation inspects on the effect of cavity’s thickness during metal casting process on the corrosion resistance of copper alloy product. As the thickness increases, the cooling rate becomes higher due to higher latent heat available in the thicker and larger cavity volume. As such the quantity of Dendritic Arm Spacing, DAS and its Secondary, SDAS per unit area becomes higher. This eventually results in better properties such as the higher hardness and good corrosion resistance because its correlation with DAS and SDAS distribution in the microstructure. The copper alloy used in this project is Nickel Aluminium Bronze (NAB) alloy which consists of elements such as the copper, aluminium, iron, nickel and manganese. Sand casting process has been used and the NAB alloys have been fabricated according to the ASTM B148 UNS 95,800 standards with the usage of 1.1% degassing agent. A range of product cavity’s thickness have been fabricated for gating system and proper machining processes have been carried out to prepare the specimens for the immersion test. The specimens were immersed in sea water for a period of 17 weeks and changes in the specimen mass and pH and TDS values of the sea water used was measured. The data analysis revealed that the specimens were not corroded yet for the period of 17 weeks as there are not much changes in the specimen mass. The pH and TDS values are showing changes but these changes are very small comparatively. 

Eduardo Souza de Cursi

Papers

A review on applications of solar energy for preheating in power plants

A review on applications of solar energy for preheating in power plants

Effect of Cavity Thickness on Copper Alloy Corrosion Resistance