Thermal analysis of a solar hybrid dehydrator designed for uniform multi-product drying

2021 ◽  
pp. 1-34
Author(s):  
Anjum Munir ◽  
Farhat Mahmood ◽  
Waseem Amjad ◽  
Syed Amjad Ahmad
Keyword(s):  
Thermal Analysis ◽  
Solar Collector ◽  
Salient Feature ◽  
Energy Utilization ◽  
Heating Source ◽  
Available Energy ◽  
Entire Height ◽  
Gas Heating ◽  
Energy Ratios ◽  
Perforated Sheet

Abstract Thermal analysis was performed for a vertical cabinet solar hybrid dryer having a salient feature of perforated sheet along its entire height to achieve uniform drying. The dryer was integrated with a solar collector and gas burner for hybrid heating source. Experiments were performed using tomato at 55°C with solar, gas, and dual (solar-gas) heating sources. Energy analysis showed that rates of energy utilization were found in ranges of 2.7-12.5 kW (dual), 3-13 kW (gas), 2.9-12 kW (solar) and energy ratios were 13-56% (dual), 14-58% (gas), 12-50% (solar). Exergy analysis showed that exergy losses were 2.1-5.0 kJ/kg (dual), 2.1-5.3 kJ/kg (gas) 1.5-4.2 kJ/kg (solar) while exergy efficiencies found 33-70% (dual), 30-75% (gas), 20-69% (solar). Based on higher values of exergetic factor and improvement potential rate (IP), it was found that optimization of heating source especially those consisting solar collector and heat exchanger (IP 1.93 kW) is required. The specific energies for the removal of product moisture and to dry the product were found 2.42, 2.72, 2.58 MJ/kg of water and 18.8, 21.2, 20.15 MJ/kg dried product for drying processes conducted under solar, gas, and dual (solar-gas) heating sources respectively. For design optimization, a complete algorithm has been prepared for complete drying systems in terms of available energy and losses.

Thermal analysis on a cascaded solar collector using nanofluid

2020 ◽  
Author(s):  
Devaraj Rangabashiam ◽  
S. Ramachandran ◽  
S. S. Rajesh ◽  
A. Ramkumar ◽  
Hemanandh Janarthanam
Keyword(s):  
Thermal Analysis ◽  
Solar Collector

Thermal Analysis of the Solar Collector Cum Storage System Using a Hybrid-Nanofluids

2021 ◽  
Vol 10 (4) ◽  
pp. 616-626
Author(s):  
Kawthar Dhif ◽  
F. Mebarek-Oudina ◽  
S. Chouf ◽  
H. Vaidya ◽  
Ali J. Chamkha
Keyword(s):  
Thermal Analysis ◽  
Steady State ◽  
Solar Collector ◽  
Heat Storage ◽  
Storage System ◽  
Stored Energy ◽  
Salt Mixture ◽  
Energy Field ◽  
Hybrid Nanofluids ◽  
Flat Plate Collector

The main problem in the solar energy field is the storage of thermal energy. To divert this problem, it was suggested to use a flat-plat solar collector which also serves as a storage system; this solution will reduce the size of a refrigerating machine that we are studying. A high stored energy density is only possible if we through use latent heat of phase change. Thermal analysis has been developed for this type of storage collector for near-steady state conditions using a nanofluid heat storage substance depended on KNO3–NaNO3 binary salt mixture as PCM and a mix of Al2O3–SiO2 as nanoparticle, from which the new Hottel-Whillier-Bliss equations have been used for efficient flat plate collector. Computations were achieved for a large variety of parameters to verify the significance of the created model.

Thermal analysis of PV system and solar collector integrated with greenhouse dryer for drying tomatoes

Energy ◽  
2020 ◽  
Vol 212 ◽  
pp. 118764 ◽  
Author(s):  
Mostafa M. Azam ◽  
Mohamed A. Eltawil ◽  
Baher M.A. Amer
Keyword(s):  
Thermal Analysis ◽  
Solar Collector ◽  
Pv System

Microgrid Power Management With Integrated Quality of Life Considerations

2020 ◽  
Author(s):  
Hailie Suk ◽  
Ayushi Sharma ◽  
Anand Balu Nellippallil ◽  
Ashok K. Das ◽  
John Hall
Keyword(s):  
Quality Of Life ◽  
Power Management ◽  
Solution Space ◽  
Salient Feature ◽  
Social Progress ◽  
Management Options ◽  
Available Energy ◽  
Grid Connection ◽  
Electrical Loads

Abstract Electrification can act as a catalyst in social progress. In some communities, grid connection is not possible. As such, microgrids are a viable alternative to provide access to electricity. Yet, progress can be impacted by challenges with insufficient energy supply. In such scenarios, it is important to understand the relationships between electricity supply and social development in managing available resources. We propose a framework to relate quality of life with power management, such that progress is not hindered when available energy is insufficient. In this paper, electrical loads for pumping water, powering streetlights, and powering household devices are examined. A compromise decision support problem (cDSP) is developed to balance the produced and consumed energy. We develop a set of power management options by exploring the solution space developed from performing the cDSP, anchored in quality of life. Organizations engaged in sustainable development can select the solution most appropriate for the community. A salient feature of the framework is the versatility. The formulation can be modified for different requirements, communities, and time periods. A test problem is used to illustrate the flexibility of the approach. This framework is constructed to support decision making for microgrid operation to continue to uplift communities.

Predator-prey ratios: a special case of a general pattern?

1992 ◽  
Vol 338 (1284) ◽  
pp. 113-130 ◽  
Keyword(s):  
General Pattern ◽  
Apparent Competition ◽  
Data Types ◽  
Predator Prey ◽  
Available Energy ◽  
Enemy Free Space ◽  
Energy Ratios ◽  
Community Data ◽  
Random Draw ◽  
Special Case

Approximately constant ratios between numbers of predator and non-predator (‘prey’) species have been observed in both community and food web data. However, only a limited set of explanations for the pattern have been considered, and interpretation is complicated by the non-equivalence of the two data types. Analysis of predator-prey ratios for a large and heterogeneous set of community data, drawn from freshwater, marine and terrestrial systems, shows that predator richness is almost, though not exactly, proportional to prey richness across and within habitats, with some suggestion that ratios differ between habitat types. Three existing, and two new, explanations for this result are considered: random draw (influence of the species pool); prey niches (more prey types provide more niches for predators); enemy-free space (the number of prey coexisting with a predator is limited by apparent competition); energy ratios (richness is proportional to available energy at each trophic level); and common determinants of diversity (factors influencing diversity act similarly on predators and prey). Separating these is not straightforward, but the latter two hypotheses have high generality, and component parts of each are supported by available evidence. We suggest that a hierarchy of processes, each of predominant importance at different scales from patches to regions, produces the observed pattern of predator-prey ratios and that, in view of these explanations, predator-prey ratios should be considered as a special case of the general problem of guild structure.

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