scholarly journals PERFORMANCE EVOLUTION OF AN IMPROVED SOLAR THERMAL HOT AIR HEATING SYSTEM FOR DRYING GROUND-NUTS

Author(s):  
Agarwal A. ◽  
Seretse O.M ◽  
Letsatsi M.T ◽  
Maele L.T ◽  
Koketso D
Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2815
Author(s):  
Florin-Emilian Țurcanu ◽  
Cătălin-George Popovici ◽  
Marina Verdeș ◽  
Vasilică Ciocan ◽  
Sebastian-Valeriu Hudișteanu

Background: The aim of our study was to identify an optimal heating system for the analyzed church. We also evaluated the energy consumption of the existing system and of those proposed in order to choose the best heating system. Methods: We analyzed the current existing heating system, a mixed system (static heaters and hot air heating) in a Romanian heritage church, build in the 16th century, and we compared it with an underfloor heating system that has been mentioned in the literature as an alternative for church heating. We used a computational fluid dynamics (CFD) analysis of the indoor climate with two turbulence models (k-ε and k-ω). Results: Comparing the two heating systems through boxplot graphs, we could highlight pertinent conclusions regarding the temperatures and velocities of the measured air currents. Thus, of all the heating systems, the underfloor heating had the lowest temperatures, but the highest air velocities, in the churchgoers area, especially under the towers zone. Conclusions: We observed that the underfloor heating system was more efficient than the existing heating system (static heaters and hot air heating), ensuring heritage conservation and high thermal comfort to the churchgoers.


Author(s):  
Octavio García Valladares ◽  
Néstor Manuel Ortiz Rodríguez ◽  
Isaac Pilatowsky Figueroa ◽  
Aidé Carolina Menchaca Valdez

2020 ◽  
Vol 148 ◽  
pp. 1302-1320 ◽  
Author(s):  
O. García-Valladares ◽  
N.M. Ortiz ◽  
I. Pilatowsky ◽  
A.C. Menchaca

Author(s):  
Vijayakumar Rajendran ◽  
Harichandran Ramasubbu ◽  
Karthick Alagar ◽  
Vignesh Kumar Ramalingam

An experimental study has been carried out to enhance a solar air heater’s performance by integrating artificial roughness through baffles on the absorber plate. In this paper, the thermal and energy matrices analysis of a Solar Air Heater (SAH) roughened with V up perforated baffles have been investigated. The effect of various mass flow rates on the SAH was analyzed with and without baffles. Experimental outputs like outlet air temperature, useful energy (heat) gain and thermal efficiency were evaluated to confirm the performance improvement. The baffled absorber plate SAH was found to give the maximum thermal efficiency and useful energy gain of 89.3% and 1321.37 W at a mass flow rate of 0.0346 kg/s, 13% and 12% higher than SAH without baffle. This result showed that the V up-shaped ribs in flow arrangement provide better thermal performance than smooth plate SAH for the parameter investigated. Energy matrices analysis and carbon dioxide mitigation of the SAH system were also analyzed.


Fluids ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 275
Author(s):  
Ahmed J. Hamad

One essential utilization of phase change materials as energy storage materials is energy saving and temperature control in air conditioning and indirect solar air drying systems. This study presents an experimental investigation evaluating the characteristics and energy savings of multiple phase change materials subjected to internal flow in an air heating system during charging and discharging cycles. The experimental tests were conducted using a test rig consisting of two main parts, an air supply duct and a room model equipped with phase change materials (PCMs) placed in rectangular aluminum panels. Analysis of the results was based on three test cases: PCM1 (Paraffin wax) placed in the air duct was used alone in the first case; PCM2 (RT–42) placed in the room model was used alone in the second case; and in the third case, the two PCMs (PCM1 and PCM2) were used at the same time. The results revealed a significant improvement in the energy savings and room model temperature control for the air heating system incorporated with multiple PCMs compared with that of a single PCM. Complete melting during the charging cycle occurred at temperatures in the range of 57–60 °C for PCM1 and 38–43 °C for PCM2, respectively, thereby validating the reported PCMs’ melting–solidification results. Multiple PCMs maintained the room air temperature at the desired range of 35–45.2 °C in the air heating applications by minimizing the air temperature fluctuations. The augmentation in discharging time and improvement in the room model temperature using multiple PCMs were about 28.4% higher than those without the use of PCMs. The total energy saving using two PCMs was higher by about 29.5% and 46.7% compared with the use of PCM1 and PCM2, respectively. It can be concluded that multiple PCMs have revealed higher energy savings and thermal stability for the air heating system considered in the current study.


2016 ◽  
Vol 92 ◽  
pp. 01049
Author(s):  
Nikolay I. Kurilenko ◽  
Pavel A. Artamonov ◽  
Elena Yu. Kurilenko ◽  
Gennady Ya. Mamontov
Keyword(s):  
Hot Air ◽  

2011 ◽  
Vol 71-78 ◽  
pp. 2073-2076
Author(s):  
Fen E Hu ◽  
Zhi Juan Wang

A solar air drying system including solar air collector, drying cabinet and air blower for notoginseng drying has been constructed and tested. Two identical air solar collectors with two air channels, V-groove absorption heat plates and a single glass cover have been employed. The results of test show that the solar air collectors can obtain a good thermal performance in winter season. When the air flow mass rate is fixed at 0.0597kg·s-1, the maximum values of thermal efficiency and outlet air temperature are 76.0% and 62.2°C, respectively. The experimental analysis between two sampling notoginseng drying suggests that the solar drying is very effective, and the drying time has been shorten to about 440 minutes from 990 minutes of the traditional drying by sun. It is also observed that using the solar drying system notoginseng has a higher quality than traditional drying method.


1989 ◽  
Author(s):  
J. Balsavich ◽  
F.E. Becker ◽  
L.A. Smolensky
Keyword(s):  

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