Thermal efficiency of vertical and horizontal-finned solar collector integrated with forced air circulation dryer for Apple as a sample

2018 ◽  
Vol 37 (5) ◽  
pp. 546-558 ◽  
Author(s):  
Maytham Ali Al-Neama ◽  
Istvan Farkas
Keyword(s):  
Thermal Efficiency ◽  
Solar Collector ◽  
Forced Air ◽  
Air Circulation

scholarly journals Air circulation in a gastrointestinal light source box and endoscope in the era of SARS-CoV-2 and airborne transmission of microorganisms

2021 ◽  
Vol 09 (03) ◽  
pp. E482-E486
Author(s):  
Stanislas Chaussade ◽  
Einas Abou Ali ◽  
Rachel Hallit ◽  
Arthur Belle ◽  
Maximilien Barret ◽  
...  
Keyword(s):  
Light Source ◽  
Cooling System ◽  
Air Cooling ◽  
Airborne Transmission ◽  
Plastic Tube ◽  
Care Workers ◽  
Air Cooling System ◽  
Forced Air ◽  
Air Circulation ◽  
Closed Environment

Abstract Background and study aims The role that air circulation through a gastrointestinal endoscopy system plays in airborne transmission of microorganisms has never been investigated. The aim of this study was to explore the potential risk of transmission and potential improvements in the system. Methods We investigated and described air circulation into gastrointestinal endoscopes from Fujifilm, Olympus, and Pentax. Results The light source box contains a lamp, either Xenon or LED. The temperature of the light is high and is regulated by a forced-air cooling system to maintain a stable temperature in the middle of the box. The air used by the forced-air cooling system is sucked from the closed environment of the patient through an aeration port, located close to the light source and evacuated out of the box by one or two ventilators. No filter exists to avoid dispersion of particles outside the processor box. The light source box also contains an insufflation air pump. The air is sucked from the light source box through one or two holes in the air pump and pushed from the air pump into the air pipe of the endoscope through a plastic tube. Because the air pump does not have a dedicated HEPA filter, transmission of microorganisms cannot be excluded. Conclusions Changes are necessary to prevent airborne transmission. Exclusive use of an external CO2 pump and wrapping the endoscope platform with a plastic film will limit scatter of microorganisms. In the era of pandemic virus with airborne transmission, improvements in gastrointestinal ventilation systems are necessary to avoid contamination of patients and health care workers.

scholarly journals Mathematical modeling and determination of thermodynamic properties of jabuticaba peel during the drying process

2016 ◽  
Vol 20 (6) ◽  
pp. 576-580 ◽  
Author(s):  
Cristian F. Costa ◽  
Paulo C. Corrêa ◽  
Jaime D. B. Vanegas ◽  
Fernanda M. Baptestini ◽  
Renata C. Campos ◽  
...  
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
Drying Process ◽  
Drying Temperature ◽  
Air Temperatures ◽  
Nutritional Qualities ◽  
Forced Air ◽  
Air Circulation ◽  
Best Fit

ABSTRACT Jabuticaba is a fruit native of Brazil and, besides containing many nutritional qualities, it also has a good field for use in products such as flour for cakes and biscuits, juice, liqueur, jelly and others. This study aimed to model the drying kinetics and determine the thermodynamic properties of jabuticaba peel at different drying air temperatures. Ripe fruits of jabuticaba (Myrciaria jaboticaba) were collected and pulped manually. Drying was carried out in a forced-air circulation oven with a flow of 5.6 m s-1 at temperatures of 40, 50, 60 and 70 °C. Six mathematical models commonly used to represent the drying process of agricultural products were fitted to the experimental data. The Arrhenius model was used to represent the drying constant as a function of temperature. The Midilli model showed the best fit to the experimental data of drying. The drying constant increased with the increment in drying temperature and promoted an activation energy of 37.29 kJ mol-1. Enthalpy and Gibbs free energy decreased with the increase in drying temperature, while entropy decreased and was negative.

scholarly journals EXAMINATION OF THE THERMAL EFFICIENCY OF THE SOLAR COLLECTOR INTEGRATED INTO THE LIGHT TRANSPARENT BUILDING FACADE

2020 ◽  
Vol 2020 (1) ◽  
pp. 30-37
Author(s):  
Stepan Shapoval ◽  
◽  
Vasyl Zhelykh ◽  
Iryna Venhryn ◽  
Khrystyna Myroniuk ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
Solar Collector ◽  
Building Facade

Industrial solar collector vs alternative solar collector: Environmental impact comparison by LCA perspective / Colector solar industrial versus colector solar alternativo: Comparação do impacto ambiental por perspectiva LCA

2021 ◽  
Vol 7 (7) ◽  
pp. 71355-71372
Author(s):  
Adrison Carvalho De Loreto ◽  
Adriane de Assis Lawisch Rodriguez ◽  
Allan Ramone de Araujo Scharnberg ◽  
Rafael Martins Da Silva ◽  
Diosnel Antonio Rodriguez Lopez ◽  
...  
Keyword(s):  
Life Cycle ◽  
Environmental Impacts ◽  
Thermal Efficiency ◽  
Solar Collector ◽  
Absorption Capacity ◽  
Environmental Evaluation ◽  
Alternative System ◽  
Life Cycle Perspective ◽  
System Use ◽  
System Verification

Adequacy to sustainable development standards requires the use of methods and tools that enable the quantification and monitoring of environmental impacts related to production processes. As a subsidy to the potential reduction of impacts by solar collectors, this paper proposes an environmental evaluation, considering an alternative solar collector scenario to be compared with a commercial one, from the life cycle perspective. Using the Life Cycle Assessment (LCA) tool, the scenarios were evaluated using the SimaPro 8.5 software. The functional unit definition was defined with real system verification through the system preparation and operation in the laboratory, which is characterized as heating 26 L of water utilizing a thermosyphon system at a temperature greater than or equal to 38 ºC. Analyzing the LCA results, it was observed that the alternative system use offers environmental impacts reduction in all impact categories selected when compared to the commercial system. In addition, a sensitivity analysis was proposed considering a variation in polyester resin mass used in the alternative system. The simulation of changes in the resin resulted in even more decreases in the environmental impacts. Regarding thermal efficiency, the industrial system excelled in terms of absorption capacity and thermal reserve. Thus, the present paper using the analyzes proposed within the defined scope, allowed the comparison between the systems in such a way that it was possible to know whether the use of the alternative solar collector results in environmental advantages without losing thermal efficiency.  

scholarly journals Determining the Effect of Inlet Flow Conditions on the Thermal Efficiency of a Flat Plate Solar Collector

Fluids ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 67 ◽  
Author(s):  
Mohammad Alobaid ◽  
Ben Hughes ◽  
Andrew Heyes ◽  
Dominic O’Connor
Keyword(s):  
Flat Plate ◽  
Thermal Efficiency ◽  
Solar Collector ◽  
Maximum Temperature ◽  
Inlet Temperature ◽  
Flow Conditions ◽  
Riser Pipe ◽  
Computational Fluid Dynamics Cfd ◽  
Flat Plate Solar Collector ◽  
Feed Temperature

The main objective of this study was to investigate the effect of inlet temperature (Tin) and flowrate ( m ˙ ) on thermal efficiency ( η t h ) of flat plate collectors (FPC). Computational Fluid Dynamics (CFD) was employed to simulate a FPC and the results were validated with experimental data from literature. The FPC was examined for high and low level flowrates and for inlet temperatures which varied from 298 to 373 K. Thermal efficiency of 93% and 65% was achieved at 298 K and 370 K inlet temperature’s respectively. A maximum temperature increase of 62 K in the inlet temperature was achieved at a flowrate of 5 × 10−4 kg/s inside the riser pipe. Tin and m ˙ were optimised in order to achieve the minimum required feed temperature for a 10 kW absorption chiller.

scholarly journals Numerical and Experimental Study on Energy Performance of Photovoltaic-Heat Pipe Solar Collector in Northern China

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Hongbing Chen ◽  
Xilin Chen ◽  
Sai Chu ◽  
Lei Zhang ◽  
Yaxuan Xiong
Keyword(s):  
Heat Pipe ◽  
Water Flow ◽  
Thermal Efficiency ◽  
Solar Collector ◽  
Water Flow Rate ◽  
Northern China ◽  
Energy Performance ◽  
Good Choice ◽  
Water Type ◽  
Pv Panel

Several studies have found that the decrease of photovoltaic (PV) cell temperature would increase the solar-to-electricity conversion efficiency. Water type PV/thermal (PV/T) system was a good choice but it could become freezing in cold areas of Northern China. This paper proposed a simple combination of common-used PV panel and heat pipe, called PV-heat pipe (PV-HP) solar collector, for both electrical and thermal energy generation. A simplified one-dimensional steady state model was developed to study the electrical and thermal performance of the PV-HP solar collector under different solar radiations, water flow rates, and water temperatures at the inlet of manifold. A testing rig was conducted to verify the model and the testing data matched very well with the simulation values. The results indicated that the thermal efficiency could be minus in the afternoon. The thermal and electrical efficiencies decreased linearly as the inlet water temperature and water flow rate increased. The thermal efficiency increased while the electrical efficiency decreased linearly as the solar radiation increased.

Experimental Studies on the Thermal Performance of the Balcony-Type Flat-Plate Solar Water Heater

2014 ◽  
Vol 953-954 ◽  
pp. 111-114
Author(s):  
Sheng Xian Wei ◽  
Fen E Hu ◽  
Dong Yu Li ◽  
Hui Li
Keyword(s):  
Water Temperature ◽  
Flat Plate ◽  
Temperature Rise ◽  
Thermal Efficiency ◽  
Solar Collector ◽  
Water Heating ◽  
Solar Water Heating ◽  
Solar Water ◽  
Daily Water Temperature ◽  
Daily Water

Based on the test methods for solar water heating systems, the unsteady thermal efficiency, the daily thermal efficiency and the daily water temperature rise of the balcony-type solar water heating system with a flat-plate solar collector fixed at a large tilt angle (≥60o) have been discussed by the experimental test in Kunming. The results indicate that the average daily thermal efficiencies of the solar collector installed at 60o, 70o, 80o and 90o are around 0.35, 0.39, 0.34 and 0.40. The intercept and the slope of the unsteady thermal efficiency equations are about 0.36~0.44 and 1.62~4.01W·°C-1·m-2. The average daily water temperature rise is 25.2°C, 20.1°C, 18.2°C and 17.4°C for the solar collector fixed at 60o, 70o, 80o and 90o.

scholarly journals Industrial Ceramic Blocks for Buildings: Clay Characterization and Drying Experimental Study

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2834
Author(s):  
A.M. Vasconcelos da Silva ◽  
J.M.P.Q. Delgado ◽  
A.S. Guimarães ◽  
W.M.P. Barbosa de Lima ◽  
R. Soares Gomez ◽  
...  
Keyword(s):  
Mass Loss ◽  
Particle Diameter ◽  
Ceramic Materials ◽  
Raw Material ◽  
Average Particle ◽  
Ceramic Block ◽  
Ceramic Blocks ◽  
Dimensional Variation ◽  
Forced Air ◽  
Air Circulation

The conformation of a ceramic piece follows the steps of preparing the raw material, molding, lamination, drying, and firing. Drying is a thermodynamic process of heat and mass transfer, with dimensional variations of the product that requires a large amount of energy. Ceramic materials when exposed to non-uniform drying may suffer cracks and deformations, reducing their post-drying quality. Thus, this work aimed to study the drying of industrial ceramic blocks in an oven with forced air circulation. Experiments were carried out to characterize the clay and drying of the ceramic block at temperatures ranging from 50 °C to 100 °C. Results of the chemical, mineralogical, granulometric, differential thermal, and thermogravimetric analysis of the clay, and heating kinetics, mass loss, and dimensional variation of the industrial ceramic block are presented and analyzed in detail. It was found that the clay is basically composed of silica and alumina (≈ 80.96%), with an average particle diameter of 13.36 μm. The study proved that drying at high temperature and low relative humidity of the air generates high rates of mass loss, heating, and volumetric shrinkage in the ceramic product, and high thermo-hydraulic stresses, which cause the appearance and propagation of cracks, gaps, and cleavages, compromising the final quality of the product.

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