scholarly journals Exergy and Energy Analyses of Microwave Dryer for Cantaloupe Slice and Prediction of Thermodynamic Parameters Using ANN and ANFIS Algorithms

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4838
Author(s):  
Safoura Zadhossein ◽  
Yousef Abbaspour-Gilandeh ◽  
Mohammad Kaveh ◽  
Mariusz Szymanek ◽  
Esmail Khalife ◽  
...  

The study targeted towards drying of cantaloupe slices with various thicknesses in a microwave dryer. The experiments were carried out at three microwave powers of 180, 360, and 540 W and three thicknesses of 2, 4, and 6 mm for cantaloupe drying, and the weight variations were determined. Artificial neural networks (ANN) and adaptive neuro-fuzzy inference systems (ANFIS) were exploited to investigate energy and exergy indices of cantaloupe drying using various afore-mentioned input parameters. The results indicated that a rise in microwave power and a decline in sample thickness can significantly decrease the specific energy consumption (SEC), energy loss, exergy loss, and improvement potential (probability level of 5%). The mean SEC, energy efficiency, energy loss, thermal efficiency, dryer efficiency, exergy efficiency, exergy loss, improvement potential, and sustainability index ranged in 10.48–25.92 MJ/kg water, 16.11–47.24%, 2.65–11.24 MJ/kg water, 7.02–36.46%, 12.36–42.70%, 11.25–38.89%, 3–12.2 MJ/kg water, 1.88–10.83 MJ/kg water, and 1.12–1.63, respectively. Based on the results, the use of higher microwave powers for drying thinner samples can improve the thermodynamic performance of the process. The ANFIS model offers a more accurate forecast of energy and exergy indices of cantaloupe drying compare to ANN model.

2020 ◽  
Vol 12 (11) ◽  
pp. 4447 ◽  
Author(s):  
Tamal Chowdhury ◽  
Hemal Chowdhury ◽  
Ashfaq Ahmed ◽  
Young-Kwon Park ◽  
Piyal Chowdhury ◽  
...  

Globally, the agriculture sector consumes a considerable portion of energy. Optimizing energy consumption and energy loss from different fuel-based types of machinery will increase the energy sustainability of this sector. Exergy analysis is a useful optimizing method that applies the thermodynamic approach to minimize energy loss. The main goal of this study is to highlight the impact of exergy loss on the energy sustainability of the agriculture sector. Hence, this study focuses on the implementation of exergy-based sustainability parameters to determine the sustainability of the agricultural sector in Bangladesh. A comprehensive analysis combining energy, exergy, and sustainability indicators was conducted based on the data obtained from 1990 to 2017. Overall energy and exergy efficiencies varied between 29.86% and 36.68% and 28.2% and 35.4%, respectively, whereas the sustainability index varied between 1.39 and 1.54. The values of relative irreversibility and lack of productivity indices from diesel fuel are higher than that of other fuel types. Maximum relative irreversibility is 0.95, whereas maximum lack of productivity is 2.50. The environmental effect factor of diesel fuel is the highest (2.47) among all the analyzed fuel types. Replacing old farming devices and selecting appropriate farming methods, appliances, and control systems will reduce exergy loss in this sector.


2015 ◽  
Vol 12 (2) ◽  
pp. 161-176 ◽  
Author(s):  
S.O. Oyedepo ◽  
R.O Fagbenle ◽  
S.S Adefila ◽  
M.M Alam

This study presents thermodynamic analysis of the design and performance of eleven selected gas turbine power plants using the first and second laws of thermodynamics concepts. Energy and exergy analyses were conducted using operating data collected from the power plants to determine the energy loss and exergy destruction of each major component of the gas turbine plant. Energy analysis showed that the combustion chamber and the turbine are the components having the highest proportion of energy loss in the plants. Energy loss in combustion chamber and turbine varied from 33.31 to 39.95% and 30.83 to 35.24% respectively. The exergy analysis revealed that the combustion chamber is the most exergy destructive component compared to other cycle components. Exergy destruction in the combustion chamber varied from 86.05 to 94.67%. Combustion chamber has the highest exergy improvement potential which range from 30.21 to 88.86 MW. Also, its exergy efficiency is lower than that of other components studied, which is due to the high temperature difference between working fluid and burner temperature. Increasing gas turbine inlet temperature (GTIT), the exergy destruction of this component can be reduced.


2020 ◽  
Vol 5 (1) ◽  
pp. 563-572
Author(s):  
Iman Golpour ◽  
Mohammad Kaveh ◽  
Reza Amiri Chayjan ◽  
Raquel P. F. Guiné

AbstractThis research work focused on the evaluation of energy and exergy in the convective drying of potato slices. Experiments were conducted at four air temperatures (40, 50, 60 and 70°C) and three air velocities (0.5, 1.0 and 1.5 m/s) in a convective dryer, with circulating heated air. Freshly harvested potatoes with initial moisture content (MC) of 79.9% wet basis were used in this research. The influence of temperature and air velocity was investigated in terms of energy and exergy (energy utilization [EU], energy utilization ratio [EUR], exergy losses and exergy efficiency). The calculations for energy and exergy were based on the first and second laws of thermodynamics. Results indicated that EU, EUR and exergy losses decreased along drying time, while exergy efficiency increased. The specific energy consumption (SEC) varied from 1.94 × 105 to 3.14 × 105 kJ/kg. The exergy loss varied in the range of 0.006 to 0.036 kJ/s and the maximum exergy efficiency obtained was 85.85% at 70°C and 0.5 m/s, while minimum exergy efficiency was 57.07% at 40°C and 1.5 m/s. Moreover, the values of exergetic improvement potential (IP) rate changed between 0.0016 and 0.0046 kJ/s and the highest value occurred for drying at 70°C and 1.5 m/s, whereas the lowest value was for 70°C and 0.5 m/s. As a result, this knowledge will allow the optimization of convective dryers, when operating for the drying of this food product or others, as well as choosing the most appropriate operating conditions that cause the reduction of energy consumption, irreversibilities and losses in the industrial convective drying processes.


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