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Anil Kumar - One of the best experts on this subject based on the ideXlab platform.
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development of indirect type Solar Dryer and experiments for estimation of drying parameters of apple and watermelon
Thermal science and engineering, 2020Co-Authors: Abhay Lingayat, V P Chandramohan, V R K Raju, Anil KumarAbstract:Abstract In the present paper, an indirect type Solar Dryer (ITSD) has been developed for apple and watermelon drying. The performance of ITSD and drying kinetics of watermelon and apple slices have been analyzed. From the experimental analysis, diffusion coefficient, surface transfer coefficients and activation energy of apple and watermelon were estimated. Experimental outcomes showed that the temperature inside the drying cabinet varied with time because of frequent variation in Solar intensity. The average thermal efficiency of the collector and Dryer was 54.5% and 25.39% during apple drying and 56.3% and 28.76% for watermelon drying, respectively. Moisture content of apple decreased from 6.16 to 0.799 kg/kg of dry basis (db) and that of watermelon reduced from 10.76 to 0.496 kg/kg of db. Drying curve was fitted with different models of existing studies. Average effective moisture diffusivity was estimated and it was 4.28 × 10−9 m2/s and 4.01 × 10−9 m2/s for apple and watermelon, respectively. Mass transfer coefficient is found to be in the range 1.584 × 10−4 to 3.158 × 10−3 m/s for apple and 5.17 × 10−4 to 4.98 × 10−3 m/s for watermelon. Heat transfer coefficient was in the range of 0.16 to 3.19 W/m2 K and 0.52 to 5.04 W/m2 K for apple and watermelon, respectively. Activation energy for apple and watermelon is 17.34 and 18.71 kJ/mol, respectively.
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exergo environmental analysis of an indirect forced convection Solar Dryer for drying bitter gourd slices
Renewable Energy, 2020Co-Authors: S. Vijayan, T. V. Arjunan, Anil KumarAbstract:Abstract In this study, a low cost indirect forced convection Solar Dryer integrated with porous bed sensible heat storage medium has been developed and studied under the climatic conditions of Coimbatore for drying bitter gourd slices. The experimental setup consists of a Solar collector with 2 m2 area, drying chamber and a centrifugal blower to force the air. The main objective of the study is to investigate the effect of mass flow rate of air on the exegetic and pickup efficiencies of the Solar drying system for drying bitter gourd slices. The results indicate that the mass of the bitter gourd slices was reduced from 4000 to 723 g in 7 h at the mass flow rate of air 0.0636 kg/s in Solar drying system. The average exergy efficiency values vary from 28.74% to 40.67% for the mass flow rates of air from 0.0141 to 0.0872 kg/s respectively. The average pickup efficiency of the drying air varied from 54.29% to 17.18% for various mass flow rates of air and it decreases with increase in mass flow rate of air. The effective moisture diffusivity of bitter gourd slices was observed from 8.6293 × 10−10 to 12.9585 × 10−10 m2/s, whereas for open sun drying it gives the lowest value of 0.9568 × 10−10 m2/s. Environmental impact analysis indicated that the energy payback time for the indirect Solar Dryer is found to be 2.21 years only. The CO2 mitigation and earned carbon credit values for the developed system are 33.52 tons and INR 10894 to 43576 for the expected lifetime of 35 years. Impact analysis shows that the Solar Dryer is a suitable solution for preserving the agricultural products with environmental sustainability.
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Experimental investigation on the comparison of fenugreek drying in an indirect Solar Dryer and under open sun
Heat and Mass Transfer, 2016Co-Authors: Vipin Shrivastava, Anil KumarAbstract:The convective heat transfer coefficient is an essential parameter for designing of any Solar drying system. In this paper heat transfer modeling in term of convective heat transfer coefficient is performed and compared with open sun drying. The data obtained from experimentation under open sun and indirect Solar drying conditions have been used to find values of the experimental constant ‘C’ and exponent ‘n’ by regression analysis and, consequently, convective heat transfer coefficient. From this study it is concluded that the convective heat transfer coefficient is decreasing with drying time it is due to decrease in moisture content. Results also showed that convective heat transfer coefficients are more in indirect Solar Dryer system than under open sun drying.
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mathematical modeling and performance analysis of thin layer drying of bitter gourd in sensible storage based indirect Solar Dryer
Innovative Food Science and Emerging Technologies, 2016Co-Authors: S. Vijayan, T. V. Arjunan, Anil KumarAbstract:Abstract An indirect forced convection Solar Dryer integrated with porous sensible heat storage medium was developed. The effect of porous thermal storage and mass flow rate of air on the performance of the system for drying bitter gourd was studied. The experimental setup consists of a blower, Solar flat plate collector with corrugated absorber plate (2 m 2 ) and a drying chamber. The thermal storage medium (pebble) is placed below the corrugated absorber plate, in the air passage as a porous medium. The experiments have been carried out with various mass flow rates of air and different drying models have been used for explaining the drying behaviour of sliced bitter gourd. The result shows that, (i) the initial moisture content 92% (w.b) of bitter gourd was reduced to 9% (w.b) in 7 h in the proposed drying system, while it was 10 h for open sun drying, (ii) the maximum specific moisture extraction rate was observed as 0.215 kg/kWh at the mass flow rate of 0.0636 kg/s and the corresponding specific energy consumption was 4.44 kWh/kg, (iii) the collector and drying efficiency of the system were 22% and 19% respectively. The two term model and Midilli–Kucuk model are most suitable for indirect Solar Dryer and open sun drying in terms of statistical parameter respectively. The drying inside sensible heat storage based indirect Dryer was more consistent and produced better quality product as compared to open sun drying. Industrial relevance • Every year post harvest losses are increasing rapidly due to the lack of storage facilities. • Solar Dryers are the most suitable technology that can be easily availed at low cost and in small scale and it can be used as an income generation option for farmers and women in rural areas. • The role of Solar Dryers in food processing industries is significant especially in developing countries in the following areas o For preserving fruits and vegetables o Dairy industries o Agricultural crop drying o Timber drying o Industrial waste drying • The utilization of thermal storage medium in the Solar Dryers is being focused much for the reasons of extending the availability of the system for operation and to achieve better quality of the products.
Sumit Tiwari - One of the best experts on this subject based on the ideXlab platform.
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energy and exergy analysis of a mixed mode greenhouse type Solar Dryer integrated with partially covered n pvt air collector
Energy, 2017Co-Authors: Sumit Tiwari, G N TiwariAbstract:In the present communication, a hybrid mixed mode greenhouse Solar Dryer, integrated with partially covered number of photovoltaic thermal (N-PVT) Solar air collectors has been proposed for drying and different performance parameters are evaluated for the climatic conditions of New Delhi, India. Thermal modelling has been done for the drying system and analytical expressions for different parameters such as crop temperature, greenhouse temperature, outlet air temperature of collector and cell temperature have been obtained. The set of governing equations has been solved with the help of MATLAB 2013a. Further, the effect of mass flow rate and variation of number of air collectors on thermal energy, electrical energy, equivalent thermal energy, thermal exergy efficiency and overall thermal efficiency have been calculated. It was found that with variation of number of air collectors from 1 to 5, equivalent thermal energy, equivalent thermal efficiency and equivalent exergy efficiency changes from 3.24 to 10.57 kWh/day, 61.56%–42.22% and 28.96%–19.11% respectively.
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Thermal analysis of photovoltaic-thermal (PVT) single slope roof integrated greenhouse Solar Dryer
Solar Energy, 2016Co-Authors: Sumit TiwariAbstract:Abstract In this research paper, a hybrid photovoltaic-thermal (PVT) single slope roof integrated greenhouse Solar Dryer under natural and forced mode has been tested for climatic condition of New Delhi, India. Thermal modelling of PVT Dryer has been experimentally validated under natural and forced mode without load condition. Further, characteristic curves have also been discussed on the basis of thermal efficiency, overall thermal efficiency, overall exergy efficiency and Solar cell efficiency including the effect of packing factor and mass flow rate. The thermal energy decreased and the electrical energy increased by 76.39% and 88.73% respectively with increment in packing factor of PV module. It was also found that with increment in mass flow rate, the thermal energy increased by 89.44% and 65.70% for natural and forced mode respectively.
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exergoeconomic analysis of photovoltaic thermal pvt mixed mode greenhouse Solar Dryer
Energy, 2016Co-Authors: Sumit Tiwari, G N TiwariAbstract:Abstract A hybrid photovoltaic-thermal (PVT) greenhouse Solar Dryer under forced mode has been proposed and different parameters have been evaluated for different climatic condition of Indian Institute of Technology, New Delhi (28_350 N, 77_120E, 216 m above MSL), India. In the present study, radiation data and ambient air temperature have been taken from IMD (Indian Meteorological Department) Pune. Further, thermal modelling has been done for the PVT greenhouse Dryer and different parameter such as crop temperature, greenhouse temperature, outlet air temperature and cell temperature have been calculated by the help of program made on MATLAB 2013a. Fair agreement has been found between theoretical and experimental data with correlation coefficient value (r) and root mean square percentage deviation (e) are 0.92 and 4.64, 0.99 and 0.97, 0.99 and 0.96 for Solar cell, greenhouse room and crop temperature respectively. Further, on yearly basis useful thermal energy, useful electrical energy, useful equivalent thermal energy, thermal exergy and overall thermal efficiency have been calculated. Further, embodied energy, energy payback time, CO 2 mitigation and carbon credit earn have also been calculated. It was found that payback time for system is 1.23 and 10 years on the basis of overall thermal energy and overall exergy basis respectively.
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performance analysis of photovoltaic thermal pvt mixed mode greenhouse Solar Dryer
Solar Energy, 2016Co-Authors: Sumit Tiwari, G N Tiwari, I M AlhelalAbstract:Abstract A hybrid photovoltaic–thermal (PVT) greenhouse Solar Dryer under mixed mode has been proposed and different parameters have been evaluated for climatic condition of Indian Institute of Technology, New Delhi (28_350N, 77_120E, 216 m above MSL), India. Further thermal modelling has been developed for the PVT greenhouse Dryer by considering different parameter namely crop, greenhouse and Solar cell temperatures, etc. Numerical computations have been done with the help of program made on MATLAB 2013a and the results are validated with experimental values. Characteristic curves have been developed for drying and system efficiency with experimental validation. Further, an overall thermal energy and exergy have been calculated. Theoretical and experimental values of overall thermal energy found to be 1.92 kW h and 2.03 kW h respectively. It can be seen that there is good agreement between theoretical and experimental value with r = 0.98 and e = 10.76. Further validation has also been done for energy and exergy of PVT Dryer.
S M Shalaby - One of the best experts on this subject based on the ideXlab platform.
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experimental investigation of a novel indirect Solar Dryer implementing pcm as energy storage medium
Energy Conversion and Management, 2014Co-Authors: S M Shalaby, M A BekAbstract:Abstract A novel indirect Solar Dryer (ISD) design using phase change material (PCM) as energy storage medium was experimentally investigated. The system consists of two identical Solar air heaters, drying compartment, PCM storage units and a blower. The ISD was tested under no load with and without PCM at a wide range of mass flow rates (0.0664–0.2182 kg/s). It is found that after using the PCM, the temperature of the drying air is higher than ambient temperature by 2.5–7.5 °C after sunset for five hours at least. In addition, the mass flow rates of 0.1204 and 0.0894 kg/s give the peak values of the drying temperature when the ISD is operated with and without PCM, respectively. The novel design successfully maintains the desired temperature for seven consecutive hours every day. This helps reaching the final moisture content of Ocimum Basilicum and Thevetia Neriifolia after 12 and 18 h, respectively.
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experimental investigation of an indirect mode forced convection Solar Dryer for drying thymus and mint
Energy Conversion and Management, 2013Co-Authors: A A Elsebaii, S M ShalabyAbstract:Abstract An indirect-mode forced convection Solar Dryer was designed and fabricated. The thermal performance of the Solar Dryer under Tanta (latitude, 30° 47′ N and longitude, 31° E) prevailing weather conditions was experimentally investigated. The system consists of a double pass v-corrugated plate Solar air heater connected to a drying chamber. A blower was used to force the heated air to the drying chamber. Drying experiments were performed for thymus (initial moisture content 95% on wet basis) and mint (initial moisture content 85% on wet basis) at an initial temperature of 29 °C. The final moisture contents for thymus and mint were reached after 34 and 5 h, respectively. Fourteen mathematical models of thin layer drying were tested to specify the suitable model for describing the drying behavior of the studied products. It was found that, Midilli and Kucuk model is convenient to describe the thin layer Solar drying of mint. However, the Page and modified Page models were found to be the best among others for describing the drying curves of thymus.
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experimental investigation of an indirect mode forced convection Solar Dryer for drying thymus and mint
Energy Conversion and Management, 2013Co-Authors: A A Elsebaii, S M ShalabyAbstract:Abstract An indirect-mode forced convection Solar Dryer was designed and fabricated. The thermal performance of the Solar Dryer under Tanta (latitude, 30° 47′ N and longitude, 31° E) prevailing weather conditions was experimentally investigated. The system consists of a double pass v-corrugated plate Solar air heater connected to a drying chamber. A blower was used to force the heated air to the drying chamber. Drying experiments were performed for thymus (initial moisture content 95% on wet basis) and mint (initial moisture content 85% on wet basis) at an initial temperature of 29 °C. The final moisture contents for thymus and mint were reached after 34 and 5 h, respectively. Fourteen mathematical models of thin layer drying were tested to specify the suitable model for describing the drying behavior of the studied products. It was found that, Midilli and Kucuk model is convenient to describe the thin layer Solar drying of mint. However, the Page and modified Page models were found to be the best among others for describing the drying curves of thymus.
S. Vijayan - One of the best experts on this subject based on the ideXlab platform.
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exergo environmental analysis of an indirect forced convection Solar Dryer for drying bitter gourd slices
Renewable Energy, 2020Co-Authors: S. Vijayan, T. V. Arjunan, Anil KumarAbstract:Abstract In this study, a low cost indirect forced convection Solar Dryer integrated with porous bed sensible heat storage medium has been developed and studied under the climatic conditions of Coimbatore for drying bitter gourd slices. The experimental setup consists of a Solar collector with 2 m2 area, drying chamber and a centrifugal blower to force the air. The main objective of the study is to investigate the effect of mass flow rate of air on the exegetic and pickup efficiencies of the Solar drying system for drying bitter gourd slices. The results indicate that the mass of the bitter gourd slices was reduced from 4000 to 723 g in 7 h at the mass flow rate of air 0.0636 kg/s in Solar drying system. The average exergy efficiency values vary from 28.74% to 40.67% for the mass flow rates of air from 0.0141 to 0.0872 kg/s respectively. The average pickup efficiency of the drying air varied from 54.29% to 17.18% for various mass flow rates of air and it decreases with increase in mass flow rate of air. The effective moisture diffusivity of bitter gourd slices was observed from 8.6293 × 10−10 to 12.9585 × 10−10 m2/s, whereas for open sun drying it gives the lowest value of 0.9568 × 10−10 m2/s. Environmental impact analysis indicated that the energy payback time for the indirect Solar Dryer is found to be 2.21 years only. The CO2 mitigation and earned carbon credit values for the developed system are 33.52 tons and INR 10894 to 43576 for the expected lifetime of 35 years. Impact analysis shows that the Solar Dryer is a suitable solution for preserving the agricultural products with environmental sustainability.
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Thermodynamic analysis of a triple-pass Solar Dryer for drying potato slices
Journal of Thermal Analysis and Calorimetry, 2019Co-Authors: S. Kesavan, T. V. Arjunan, S. VijayanAbstract:An indirect-type triple-pass forced convection Solar Dryer has been developed and the performance parameters such as thermal, pickup and exergy efficiency are studied for drying potato slices. The triple-pass Solar Dryer consists of a blower, triple-pass Solar collector integrated with sensible heat storage (sand) bed along with absorber plate and aluminum wire mesh and drying chamber. The experiments were conducted at the optimum value of air mass flow rate of 0.062 kg s^−1. The experimental results showed that the maximum collector outlet air temperature of 62 °C was observed at 1.00 pm and the respective Solar irradiance of 998 W m^−2. The initial moisture content of the potato slices was reduced from 76% (wet basis) to the final moisture content of 13% (wet basis) in 4.5 h. The Solar collector thermal efficiency was varied from 12 to 66%, and the mean value of 45% was observed. The pickup efficiency of the Solar Dryer for drying potato slices was varied from 2.5 to 62.9%, and an average of 29.9% was observed. The exergy efficiency varies from 2.8 to 87.02%, and the mean value for the day was obtained as 53.57%. The thin-layer drying characteristics of potato slices have been studied, and Midilli and Kucuk model was proposed as most suitable drying model.
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mathematical modeling and performance analysis of thin layer drying of bitter gourd in sensible storage based indirect Solar Dryer
Innovative Food Science and Emerging Technologies, 2016Co-Authors: S. Vijayan, T. V. Arjunan, Anil KumarAbstract:Abstract An indirect forced convection Solar Dryer integrated with porous sensible heat storage medium was developed. The effect of porous thermal storage and mass flow rate of air on the performance of the system for drying bitter gourd was studied. The experimental setup consists of a blower, Solar flat plate collector with corrugated absorber plate (2 m 2 ) and a drying chamber. The thermal storage medium (pebble) is placed below the corrugated absorber plate, in the air passage as a porous medium. The experiments have been carried out with various mass flow rates of air and different drying models have been used for explaining the drying behaviour of sliced bitter gourd. The result shows that, (i) the initial moisture content 92% (w.b) of bitter gourd was reduced to 9% (w.b) in 7 h in the proposed drying system, while it was 10 h for open sun drying, (ii) the maximum specific moisture extraction rate was observed as 0.215 kg/kWh at the mass flow rate of 0.0636 kg/s and the corresponding specific energy consumption was 4.44 kWh/kg, (iii) the collector and drying efficiency of the system were 22% and 19% respectively. The two term model and Midilli–Kucuk model are most suitable for indirect Solar Dryer and open sun drying in terms of statistical parameter respectively. The drying inside sensible heat storage based indirect Dryer was more consistent and produced better quality product as compared to open sun drying. Industrial relevance • Every year post harvest losses are increasing rapidly due to the lack of storage facilities. • Solar Dryers are the most suitable technology that can be easily availed at low cost and in small scale and it can be used as an income generation option for farmers and women in rural areas. • The role of Solar Dryers in food processing industries is significant especially in developing countries in the following areas o For preserving fruits and vegetables o Dairy industries o Agricultural crop drying o Timber drying o Industrial waste drying • The utilization of thermal storage medium in the Solar Dryers is being focused much for the reasons of extending the availability of the system for operation and to achieve better quality of the products.
M C Ndukwu - One of the best experts on this subject based on the ideXlab platform.
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development of a low cost wind powered active Solar Dryer integrated with glycerol as thermal storage
Renewable Energy, 2020Co-Authors: M C Ndukwu, D Onyenwigwe, Fidelis I Abam, A B Eke, C DiriohaAbstract:Abstract The paper presents an active mix-mode wind-powered fan Solar Dryer (AWPFS) with a passive mix-mode non-wind-powered Solar Dryer (PNWPS) evaluated with pre-treated potato slices. The two Dryers were tested with and without glycerol as thermal energy storage. The objective was to present a non-electricity powered active Solar Dryer using only clean energy sources. Evaluation of the Dryer took place at ambient temperature range of 24–50 °C and humidity of 10–52%. The results indicate that drying with AWPFS integrated with glycerol showed shorter drying time than drying with AWPFS only or PNWPS. Dipping the potato in a salt solution and blanching for 30 s before drying quickened the drying rate of the potato compared to other treatments. The energy consumed for drying ranged from 4.10 to 4.98 MJ, while the specific energy consumption ranged from 2.846 to 3.686 kWh/kg. The drying efficiencies ranged from 25.031% to 31.5%, while the exergy efficiency ranged from 14.5 to 80.9%. With low electricity penetration density across Africa, this Dryer with naturally powered fan will help crop processors dry their product faster and about 15.3–290.4 $/year could be saved at 10–100% rate of usage
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numerical analysis and validation of a natural convection mix mode Solar Dryer for drying red chilli under variable conditions
Renewable Energy, 2020Co-Authors: Merlin Simotagne, M C Ndukwu, Andre Zoulalian, Lyes Bennamoun, Fatima Kifanisahban, Yann RogaumeAbstract:Abstract The objective of this paper is to model a natural convection mix-mode Solar Dryer (NCMMSD) for drying agricultural products in an environment with short sunshine duration. The Solar Dryer was used to dry red chilli and was operating under the climate of the coastal area of South Eastern Nigeria characterized by low Solar radiation intensity with a short duration of sunshine hours. The model took into consideration the thermophysical properties of the drying air and dried red chilli. The simultaneous heat and mass transfer equations were solved using the fourth-order Runge-Kutha method. The numerical solution allows for the determination of temperature and relative humidity of drying air at different points within the Dryer as well as the moisture profile of the dried product. The experimental values of moisture ratios, temperature, and relative humidity during the mix-mode Solar drying process with and without NaCl were used to validate the proposed model. Numerical simulation results were in close agreement with experimental results. The present model can serve as good reference bases to explain the drying phenomenon of mix-mode Solar drying of other agricultural products when necessary thermophysical properties of these products are known. Using this model, the potential of mitigating gross fossil (coal) CO2 in Africa is annually estimated to 1280148 tons of CO2.
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energy and exergy analysis of a Solar Dryer integrated with sodium sulfate decahydrate and sodium chloride as thermal storage medium
Renewable Energy, 2017Co-Authors: M C Ndukwu, Fidelis I Abam, A B Eke, Lyes Bennamoun, D UkohaAbstract:Abstract Energy and exergy-based performances of a natural-convective Solar Dryer (NCSDR) integrated with sodium sulfate decahydrate (Na2SO4·10H2O) and sodium chloride (NaCl) as thermal storage medium are presented. The NCSDR was operational in Nigerian climate and applied for red chilli. The objectives of this study were to evaluate the thermal storage potential of Na2SO4·10H2O and NaCl with focus on energy consumption and exergy-sustainability indicators. The performances were compared to control-experiment conditions. The results showed that NCSDR integrated with Na2SO4·10H2O, NaCl, and the control-experiment reduced the moisture content of red chilli from 72.27% to 7.6, 10.1 and 10.3% respectively. While, the overall drying efficiency and energy consumption of the three scenarios varied from 10.61 to 18.79% and 7.54–12.98 MJ respectively. The exergy efficiency for the drying system during sunshine-hours ranged from 66.79 to 96.09%. The exergy efficiency of drying using Na2SO4·10H2O thru off-sunshine hours and overall exergy-efficiency of the entire drying process were 81.19 and 66.82% respectively. Furthermore, the exergy-based sustainability indicators, waste-exergy ratio, sustainability index and improvement potential for sunshine-hours ranged from 0.166 to 0.174, 3.01 to 8.15 and 1.285–1.295 W respectively. Approximately 602 tonnes/year of CO2 could be limited from entering the air using Na2SO4·10H2O as thermal storage medium compared to diesel powered Dryer.