Review on Performance Enhancement Studies on Solar Dryer

2015 ◽  
Vol 787 ◽  
pp. 129-133
Author(s):  
A.S. Ramana ◽  
T.V. Ashokumaar ◽  
K. Vignesh
Keyword(s):  
Solar Energy ◽  
Large Scale ◽  
Performance Enhancement ◽  
Cost Effective ◽  
Optimization Techniques ◽  
Heating Process ◽  
Thermal Systems ◽  
Drying Time ◽  
Solar Dryer ◽  
Drying System

Abundant availability of solar energy and fast depleting fossil fuel reserves have necessitated deployment of large scale solar thermal systems for meeting the space heating, process heating and drying requirements. Researchers worldwide have focused on developing energy efficient dryer capable of enhancing product quality, reduced drying time, high throughput, minimal pre-treatments prior to drying with less energy loss in cost effective way. The present paper surveys literature on performance enhancement studies on solar dryer with a thrust on energy efficiency improvements in solar air collector and a multipurpose solar drying system. The effect of adoption of absorber plate with different types of fins, design modifications, CFD based optimization techniques and incorporation of storage materials have been reviewed. A dual-purpose solar water heating and drying system with phase change material (PCM) is suggested for effective harnessing of solar energy.

scholarly journals Enabling Large-Scale Simulations of Quantum Transport with Manycore Computing

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 253
Author(s):  
Yosang Jeong ◽  
Hoon Ryu
Keyword(s):  
Quantum Transport ◽  
Large Scale ◽  
Performance Enhancement ◽  
Silicon Nanowire ◽  
Matrix Multiplication ◽  
Tight Binding ◽  
Optimization Techniques ◽  
Wide Energy Range ◽  
Processing Unit ◽  
Binding Model

The non-equilibrium Green’s function (NEGF) is being utilized in the field of nanoscience to predict transport behaviors of electronic devices. This work explores how much performance improvement can be driven for quantum transport simulations with the aid of manycore computing, where the core numerical operation involves a recursive process of matrix multiplication. Major techniques adopted for performance enhancement are data restructuring, matrix tiling, thread scheduling, and offload computing, and we present technical details on how they are applied to optimize the performance of simulations in computing hardware, including Intel Xeon Phi Knights Landing (KNL) systems and NVIDIA general purpose graphic processing unit (GPU) devices. With a target structure of a silicon nanowire that consists of 100,000 atoms and is described with an atomistic tight-binding model, the effects of optimization techniques on the performance of simulations are rigorously tested in a KNL node equipped with two Quadro GV100 GPU devices, and we observe that computation is accelerated by a factor of up to ∼20 against the unoptimized case. The feasibility of handling large-scale workloads in a huge computing environment is also examined with nanowire simulations in a wide energy range, where good scalability is procured up to 2048 KNL nodes.

scholarly journals Solar drying of jack fruit almonds

2011 ◽  
Vol 31 (6) ◽  
pp. 1150-1161 ◽  
Author(s):  
Alexandre J. de M Queiroz ◽  
Hermeval J Dantas ◽  
Rossana M. F. de Figueirêdo ◽  
Karla dos S Melo
Keyword(s):  
Solar Energy ◽  
Heat Source ◽  
The Sun ◽  
Solar Drying ◽  
Drying Time ◽  
Solar Dryer

Dryers heated by solar energy have been constructed and used in drying whole and half jack fruit almonds. The samples were dried during the day in direct sun and in the conventional solar dryer prepared for this purpose. Another piece of equipment was built for reception and accumulation of sun energy in a body of water, which was used as a heat source for night drying. The drying with the sun energy was compared with artificial drying. The jack fruit almonds were dried whole, half, with pellicle and without it. The storage of solar energy in water was technically viable for use in night drying. The drying by combining solar dryers in the day and night periods were completed in approximately 35 hours, and were equivalent to artificial drying between 40ºC and 70ºC. Almond cut in half and the pellicle removed reduced the drying time.

scholarly journals Shadow enhanced self-charging power system for wave and solar energy harvesting from the ocean

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qian Zhang ◽  
Qijie Liang ◽  
Dilip Krishna Nandakumar ◽  
Hao Qu ◽  
Qiongfeng Shi ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Solar Energy ◽  
Power System ◽  
Large Scale ◽  
Moving Objects ◽  
Photovoltaic Cells ◽  
Cost Effective ◽  
Shadow Effect ◽  
Solar Energy Harvesting ◽  
Energy Ball

AbstractHybrid energy-harvesting systems that capture both wave and solar energy from the oceans using triboelectric nanogenerators and photovoltaic cells are promising renewable energy solutions. However, ubiquitous shadows cast from moving objects in these systems are undesirable as they degrade the performance of the photovoltaic cells. Here we report a shadow-tribo-effect nanogenerator that hybrids tribo-effect and shadow-effect together to overcome this issue. Several fiber-supercapacitors are integrated with the shadow-tribo-effect nanogenerator to form a self-charging power system. To capture and store wave/solar energy from oceans, an energy ball based on the self-charging power system is demonstrated. By harnessing the shadow-effect, i.e. the shadow of the moving object in the energy ball, the charging time shortens to 253.3 s to charge the fiber-supercapacitors to the same voltage (0.3 V) as using pure tribo-effect. This cost-effective method to harvest and store the wave/solar energy from the oceans in this work is expected to inspire next-generation large-scale blue energy harvesting.

Improvement of the Thermal Performance of Solar Drying Systems Using Different Techniques: A Review

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Messaoud Sandali ◽  
Abdelghani Boubekri ◽  
Djamel Mennouche
Keyword(s):  
Heat Pump ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Solar Drying ◽  
Drying Time ◽  
Buoyant Force ◽  
Circulation Mode ◽  
Solar Dryer ◽  
Drying System ◽  
Air Circulation

Solar drying is one of the most important processes of preserving agricultural products. This review paper focused mainly on the enhancement of efficiency a solar drying system. The establishment of different techniques and factors, which may affect the performance of solar dryers, helps to improve solar dryers’ effectiveness. Different types of solar dryers were described here; moreover, various performance analyses of solar drying systems (SDSs) were presented. Factors and techniques for improving efficiency of solar dryers were discussed as well. The effect of operating conditions, geometrical conditions, adding of reflectors, heat exchanger, heat pump, photovoltaic source, air circulation mode, and phase change material (PCM) on the efficiency of a solar drying system were studied and discussed. Results showed that climatic conditions such as ambient temperature and solar radiation have an important influence on the solar dryer performance. The chimney integrated in solar dryer increases the buoyant force applied on the air stream to maintain a greater air flow velocity, which removes one side of moisture. The concentrators found to be effective in reducing the drying time by increasing the air temperature inside the dryer. Photovoltaic panels provides electricity source to run electrical components such as the fan to provide a forced air circulation that removes more moisture from the product compared with the natural convection or the heat pump to ensure the drying process at night. PCMs store the thermal energy during sunshine hours and release it after sunset, which can reduce the heat losses and improve the thermal efficiency of the drying system.

scholarly journals An active indirect solar system for food products drying

2019 ◽  
Vol 12 (1) ◽  
pp. 142-149 ◽  
Author(s):  
Abdul Wasim Noori ◽  
Mohammad Jafar Royen ◽  
Juma Haydary
Keyword(s):  
Ambient Temperature ◽  
Air Temperature ◽  
Food Products ◽  
Sample Thickness ◽  
Drying Process ◽  
Rectangular Section ◽  
Drying Time ◽  
Solar Dryer ◽  
Temperature And Humidity ◽  
Drying System

AbstractAn energy independent active indirect solar drying system for the study of food products drying at specific climate conditions was developed and tested. As a model material, sliced tomato was selected because of its short shelf live, high humidity and potential to be a high value dried product. Indirect solar dryer enabled complete protection of the dried material against sunlight, birds, insects, rain and dust during the drying process. The solar dryer system design includes a rectangular section (1000 × 600 × 400) mm chamber and a flat solar collector (1500 × 600 × 100) mm with the surface area of 0.9 m2. Air flow was induced by a fan installed at the inlet of the collector and powered by a photovoltaic solar panel and a battery system. Temperature and humidity of air were monitored at the collector inlet, collector outlet and the drying chamber outlet. The key element of the collector is a 10.5 m long rectangular section aluminum pipe (55 × 35) mm coated with an absorption layer. The maximum dryer capacity is around 3 kg of wet material (sliced tomato) per batch. Average air temperature increase in the collector was measured to be 30 °C during the winter season. Air relative humidity decreased from 21 % to 15 % after passing through the collector. The moisture of tomato slices decreased from the initial value of 92 % down to 22 % during the time of the experiment (30 h). Quality of tomatoes dried using the designed solar dryer differed significantly in color as well as in texture from those dried by the commonly used methods, like an open sun drying system. Equilibrium moisture content of the product was reached after 30 h in December when the maximum outside temperature was 17.6 °C. The tomato mass decreased from 333 g to 33.15 g; the mass loss being approximately 90 %. The heated air temperature and humidity at the dryer inlet and outlet were influenced by the change of the ambient temperature and humidity during the day. Variation of the drying rate with the change of the ambient temperature and humidity was observed. During summer, when the sun radiation increases, the drying time for sliced tomato with 9 mm thickness decreased from 25 h to 15 h. The sample thickness also has an impact on the drying process. When the sample thickness increased from 9 mm to 12 mm, the drying time increased from 15 h to 20 h of active device time.

scholarly journals Augmenting natural convection and conduction based solar dryer

2018 ◽  
Author(s):  
B. Thorat ◽  
A. Chavan ◽  
A. Sikarwar ◽  
V. Tidke
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Solar Energy ◽  
Boundary Conditions ◽  
Cost Effective ◽  
Global Market ◽  
Cfd Modeling ◽  
Solar Insolation ◽  
Radiation Mechanism ◽  
Drying System

Solar conduction dryer (SCD) is a unique technology that uses conduction, convection and radiation mechanism of heat transfer making it one of the most efficient drying system. The SCD is one of the most effective piece of equipment’s designed indigenously and it has tremendous potential to capitalize in erstwhile nations of tropical and torrid region where there is abundance of solar insolation. SCD, the most cost-effective dryer which runs on no electricity has already made inroads in the global market. In the present study, CFD studies were carried out for a given geometry and the corresponding boundary conditions. Keywords: Solar Energy; Solar Conduction Dryer; CFD modeling 

scholarly journals Performance Enhancement of a Sludge Continuous Feed Heat Pump Drying System by Air Deflectors and Auxiliary Cooling Subsystems

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6651
Author(s):  
Win-Jet Luo ◽  
Cheng-Yan Lin ◽  
Nai-Feng Wu ◽  
Zhi-Qun Xu
Keyword(s):  
Performance Enhancement ◽  
Heat Pumps ◽  
Drying Time ◽  
Operational Conditions ◽  
Subsystem Design ◽  
Airflow Field ◽  
Continuous Feed ◽  
Drying System ◽  
Improved Design ◽  
Drying Chamber

This study proposes an improved design for a typical sludge continuous feeding drying system connected with three air-source heat pumps. The system’s performance was further improved using air-deflectors on the drying chamber’s internal sidewalls, enhancing the heat and mass transfer between the conveyor sludge and circulating airflow. In this study, numerical analysis was performed to elucidate the deflector designs on the airflow field and thermal temperature field distributions in the drying chamber. The specific moisture extraction rate (SMER) value was quantified to evaluate the system’s overall improvement during experiments. With a suitable deflector design, the average percent water content in sludge could be further reduced to 22.2% with drying time of 18.3 h, and the SMER value could be enhanced from 1.38 kg/kWh to as high as 1.83 kg/kWh with an increment of 32.44%. Moreover, to prevent overloading and frequent shutdown of the compressors, an auxiliary cooling subsystem was designed to attain stable operational conditions. By the auxiliary cooling subsystem design, the compressors’ shutdown can be avoided, the temperature difference between airflow inlets and outlet of the drying chamber can be increased, and SMER value can be further increased to a value of 1.94 kg/kWh.

scholarly journals Development and effectiveness of greenhouse type solar dryer for coriander leaves

2022 ◽  
Vol 43 (1) ◽  
pp. 85-96
Author(s):  
S.K. Singh ◽  
◽  
Mr. Samsher ◽  
B.R. Singh ◽  
R.S. Sengar ◽  
...  
Keyword(s):  
Qualitative Evaluation ◽  
Ascorbic Acid Content ◽  
Cost Effective ◽  
Quality Parameters ◽  
Leafy Vegetables ◽  
Rehydration Ratio ◽  
Drying Time ◽  
Sun Drying ◽  
Solar Dryer ◽  
Coriander Leaves

Aim: Sun drying system is not able to provide the best drying performance and quality dried produce of leafy vegetables. To facilitate better options to the farmers, this study aims to develop and evaluate a cost-effective greenhouse type solar dryer to improve shelf stability of coriander leaves. Methodology: A greenhouse type solar dryer (5m x 3m x 2.3m) was developed with the provision of rigid frame, 200 µ UV stabilized LDPE glazing material, solar collector cum drying chamber, inlet air and outlet air openings. The dryer was evaluated for its performance, drying characteristics of coriander leaves and qualitative evaluation of dried product as compared to open sun drying. Results: The greenhouse type solar dryer performed well for coriander drying with increased level of temperature inside the dryer (42oC) and 24% reduced drying time as compared to sun drying (29oC).The loading capacity, efficiency, payback period and B:C ratio of the dryer were found to be 100 kg, 70.47 %, 1.26 yr and 1.79, respectively. The drying of coriander leaves occured mostly in falling rate period. Coriander leaves dried under the dryer possessed higher values of chlorophyll content (1.356 mg g-1 of tissue), ascorbic acid content (111.257 mg 100g-1), rehydration ratio (5.302) and coefficient of rehydration (0.762) than sun dried coriander leaves with the respective values of these quality parameters being 1.097 mg g-1 of tissue, 62.37 mg 100g-1, 4.715 and 0.689, respectively.

A Review of Various Nanostructures to Enhance the Efficiency of Solar-Photon-Conversions

2015 ◽  
pp. 277-312
Author(s):  
S. A. Akhoon ◽  
S. Rubab ◽  
M. A. Shah
Keyword(s):  
Solar Cells ◽  
Energy Harvesting ◽  
Solar Energy ◽  
Alternative Energy ◽  
Large Scale ◽  
Cost Effective ◽  
Energy Utilization ◽  
Electron Collection ◽  
Solar Hydrogen Production ◽  
Cost Efficient

The problem of dwindling energy can be attributed to the rapidly increasing worldwide energy demand, leading to an urgent need for alternative energy-harvesting technologies to sustain the economic growth by maintaining our appetite for energy. Among them, solar-energy-harvesting is most promising, and the huge demand for clean, cost-effective, and cost-efficient energy can be met by solar energy. The large-scale solar energy utilization has not become practical because of the high cost and inadequate efficiencies of the current solar-energy-conversions. Nanotechnology offers tools to develop cost-effective and cost-efficient technologies for solar-energy conversions. Nanostructures, such as nanowires, nanopillars, nanodomes, nanorods, quatumdots, nanoparticles, etc., facilitate photon absorption, electron transport, and electron collection properties of the solar-energy-conversion devices. This review specifically summarizes the contribution of the nanotechnology to photovoltaics, dye-sensitive solar cells, quantum-dot-sensitized solar cells, and solar hydrogen production devices.

Recent developments in heterogeneous photocatalysts for solar-driven overall water splitting

2019 ◽  
Vol 48 (7) ◽  
pp. 2109-2125 ◽  
Author(s):  
Zheng Wang ◽  
Can Li ◽  
Kazunari Domen
Keyword(s):  
Solar Energy ◽  
Water Splitting ◽  
Large Scale ◽  
Cost Effective ◽  
Hydrogen Energy ◽  
Overall Water Splitting ◽  
Effective Technology ◽  
Recent Developments ◽  
Renewable Hydrogen

Overall water splitting based on particulate photocatalysts is an easily constructed and cost-effective technology for the conversion of abundant solar energy into clean and renewable hydrogen energy on a large scale.

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