scholarly journals Thermal Analysis of a Solar Assisted Cold Storage Unit for the Storage of Agricultural Perishables Produce

2021 ◽  
Vol 12 (1) ◽  
pp. 24
Author(s):  
Waseem Amjad ◽  
Fatima Akram ◽  
Sidrah Rehman ◽  
Anjum Munir ◽  
Owais Manzoor
Keyword(s):  
Thermal Analysis ◽  
Cold Storage ◽  
Exergy Efficiency ◽  
Energy Utilization ◽  
Coefficient Of Determination ◽  
Cooling Process ◽  
Storage Unit ◽  
Average Value ◽  
Cubic Model ◽  
Utilization Ratio

A solar based cold storage unit for the preservation of food products is an excellent way to reduce post-harvest losses at lower energy costs. Energy optimization is essential to improve the reliability of the system. In the case of cooling, a major factor to reduce energy consumption is the uniform distribution of air inside the cooling chamber to maintain the even temperature of stored products. For this, a detailed thermal analysis is required to analyse the cooling process for energy saving and optimum conditions. In the current study, an energy and exergy based thermal analysis of a solar assisted cold storage unit is presented. A parametric investigation and a proper understanding about the influence of thermodynamics on the cooling process were obtained. All the experimentally calculated parameters (energy utilized, energy utilization ratio, energy loss and exergy efficiency) were subjected to a model curve fitting using Sigmaplot-12 and a polynomial cubic model was found best fitted based on the values of coefficient of determination. Thermal analysis showed variations in the rate of energy utilization, energy utilization ratio, exergy losses and exergy efficiency in the range of 3–18 kJ/s, 0.37–0.80, 0.8–2.25 kJ/s and 40–60%, respectively. The average value of COP of the system was found to be 3.95.

Microwave Field Distribution Uniformity Coefficient in the Grain Mass

2020 ◽  
Vol 67 (2) ◽  
pp. 87-92
Author(s):  
Dmitriy A. Budnikov
Keyword(s):  
Electromagnetic Field ◽  
Numerical Experiment ◽  
Microwave Field ◽  
Research Purpose ◽  
Coefficient Of Determination ◽  
Material Research ◽  
Dense Layer ◽  
Uniformity Coefficient ◽  
Average Value ◽  
Processed Material

The article considers the microwave electromagnetic fields as one of the options for improving the thermal drying of grain. Their application is limited by the high unevenness of the field propagation in the layer of the processed material. (Research purpose) The research purpose is in justifying the uniformity of distribution of microwave field in the layer of the processed grain. (Materials and methods) The article presents the scheme of computer models of microwave processing zones and waveguides, properties of materials for conducting a numerical experiment. (Results and discussion) A numerical experiment was performed to determine the uniformity coefficient of propagation of the microwave field in a layer of grain material. The article presents the dependencies. (Conclusions) It was found that the results of modeling the distribution of the electromagnetic field in the zone of microwave convective influence of the installation containing two sources of microwave power for processing the grain layer indicate a high level of its unevenness in the volume of the product pipeline. To assess the uniformity of the distribution of the electromagnetic field in the working area of a laboratory installation, there used a coefficient that is the ratio of the average value of the intensity in the zone of microwave convective action to its average value of the wave strength passing through the output of the waveguide. The values of the uniformity coefficient in the considered implementation options are in the range of 0.1757-0.4946 for a dense layer of wheat. To ensure a sufficient level of uniformity of the electromagnetic wave distribution in the volume of the microwave convective zone, the uniformity coefficient must be higher than 0.37. The article presents the dependence of the uniformity coefficient of the electromagnetic field on the humidity of the processed material by a third-degree polynomial with a coefficient of determination higher than 0.98.

scholarly journals Energetic and exergetic analysis of a convective drier: A case study of potato drying process

2020 ◽  
Vol 5 (1) ◽  
pp. 563-572
Author(s):  
Iman Golpour ◽  
Mohammad Kaveh ◽  
Reza Amiri Chayjan ◽  
Raquel P. F. Guiné
Keyword(s):  
Energy Consumption ◽  
Research Work ◽  
Specific Energy Consumption ◽  
Exergy Efficiency ◽  
Operating Conditions ◽  
Energy Utilization ◽  
Convective Drying ◽  
Drying Time ◽  
Energy And Exergy ◽  
Exergy Losses

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.

scholarly journals ANALISA ENERGI DAN EKSERGI PADA PENGERINGAN TEPUNG TAPIOKA MENGGUNAKAN PENGERING KONTINYU UNGGUN FLUIDISASI GETAR

REAKTOR ◽  
2016 ◽  
Vol 16 (1) ◽  
pp. 24 ◽  
Author(s):  
Suherman Suherman ◽  
Rona Trisnaningtyas
Keyword(s):  
Energy Efficiency ◽  
Fluidized Bed ◽  
Exergy Analysis ◽  
Cassava Starch ◽  
Energy Utilization ◽  
Exergetic Efficiency ◽  
Energy And Exergy ◽  
Vibrated Fluidized Bed ◽  
Energy And Exergy Analysis ◽  
Utilization Ratio

Energy and exergy analysis of cassava starch drying in continuous vibrated fluidized bed dryer were carried out to assess the performance of the system in terms of energy utilization ratio, energy efficiency, exergy inflow and outflow, exergy loss, and exergetic efficiency. The results showed cassava starch has starch content 87%, degree of whiteness 95%, negative fiber content, sperichal granula with average diameter12.32 μm, orthorhombic crystal structure and crystal size 47.467 nm . Energy utilization and energy utilization ratio increased from 0.08 to 0.20 J/s and 0.35 to 0.4 as the drying temperature  increased from 50 to 70 oC. Energy efficiency increased from 13.80 % to 23.31 %, while exergy inflow, outflow, and losses increased from 4.701 to 14.678, 2.277 to 6.344, and 2.424 to 8.334 J/s respectively in the above temperature range. Exergetic efficiency decreased with increase in drying air temperature, while exergetic improvement potential increased with increased drying air temperature. Keywords: Cassava starch, continuous drying, energy and exergy analysis, vibrated fluidized bed Abstrak Analisis energi dan eksergi pengeringan pati tapioka menggunakan pengering kontinu unggun fluidisasi getar, telah dilakukan untuk menilai kinerja sistem dalam bentuk utilisasi energi, efisiensi energi, eksergi masuk dan keluar, eksergi hilang dan efisiensi eksergi. Hasil analisis pati memiliki kandungan starch 87%, tingkat keputihan 95%, kandungan serat negatif, bentuk partikel granular spherical dengan diameter 12,32 μm, struktur kristal orthorhombic dan ukuran kristal sebesar 47,467 nm. Peningkatan suhu pengering dari 50 menjadi 70 0C akan meningkatkan utilisasi energi dan rasio utilisasi energi dari 0,08 menjadi 0,20 J/s dan 0,35 menjadi 0,4. Efisiensi energi meningkat dari 13,80% hingga 23,31%, sedangkan eksergi masuk dan keluar, eksergi hilang meningkat dari 4,701 menjadi 14,678, 2,277 menjadi 6,344, dan 2,424 menjadi 8,334 J/s. Efisiensi eksergi menurun dengan naiknya suhu sedangkan potensi pengembangan eksergi meningkat dengan naiknya suhu. Kata kunci:. Analisis energi dan eksergi, pati tapioka, pengeringan kontinu, unggun fluidisasi getar

scholarly journals Thermal Analysis of Cooling Process of Sheet Molding (II)

Seikei-Kakou ◽  
1994 ◽  
Vol 6 (11) ◽  
pp. 735-739
Author(s):  
Hideharu Kimura ◽  
Mitsuhiro Imaizumi
Keyword(s):  
Thermal Analysis ◽  
Cooling Process

Comparison of Different Energy Storage Systems for a Small Airport Facility

2018 ◽  
Author(s):  
Shahin Shafiee ◽  
Mary Helen McCay
Keyword(s):  
Renewable Energy ◽  
Energy Storage ◽  
Rural Areas ◽  
Wind Farm ◽  
Renewable Energy Sources ◽  
Storage System ◽  
Energy Utilization ◽  
Storage Unit ◽  
Power Requirement ◽  
Technical Requirements

Airports, one of the important transportation components in this modern age, are under continuous improvement especially in regard to energy sustainability. While most work is concentrated on large airports, smaller airports which are mostly scattered around rural areas seem to be better opportunities for renewable energy utilization. However, while renewable energy has come into use at airports over the past decade, it has been at a slow pace and has not included storage. A reliable storage system can significantly increase the power reliability of a small airport and make a renewable energy system viable. Acquiring the technical requirements of a facility based on its characteristics enables the designer to evaluate the power source options and develop an efficient storage system. The current paper analytically develops a framework to design and integrate an energy storage method for a renewable system into a small airport facility. The framework details include methods for energy storage which are environmentally acceptable in combination with renewable energy sources to produce electrical power for the on-site facilities. The technical analysis which leads to the sizing of the storage unit initiates with categorizing different methods for energy storage and their applicability to an airport facility for off-grid and on-grid modes. Based on the results and conclusions from the first step, the search is narrowed down to mediums for electricity storage for a wind farm or solar power plant. In such a case, the main applications of the storage unit could be either to supply power to the facility during the transition time from the renewable source to the main grid or to regulate the power frequency of the generation unit. Capacitors and batteries were selected as the two options for the given power requirement of the facility. Considering the wide variety of available technologies and lower costs, the appropriate storage system is proposed for both long term and short term applications. A table is presented to compare available battery technologies and their respective storage capacities.

scholarly journals Experimental Analysis on Refrigerant Charge Optimization for Cold Storage Unit

2017 ◽  
Vol 205 ◽  
pp. 1108-1114 ◽  
Author(s):  
Xinhao Hu ◽  
Zhongbin Zhang ◽  
Yuchen Yao ◽  
Qing Wang
Keyword(s):  
Cold Storage ◽  
Experimental Analysis ◽  
Storage Unit

Estimating Provincial Economic Development Level of China Using DMSP/OLS Nighttime Light Satellite Imagery

2013 ◽  
Vol 807-809 ◽  
pp. 1903-1908 ◽  
Author(s):  
Liang Tang ◽  
Hui Cheng ◽  
Ge Qu
Keyword(s):  
Economic Development ◽  
Satellite Imagery ◽  
Regional Economic Development ◽  
Coefficient Of Determination ◽  
Regional Economic ◽  
Development Level ◽  
Nighttime Light Data ◽  
Cubic Model ◽  
Nighttime Light ◽  
Development Levels

How to estimate regional economic development level is important for solving regional inequality problems. Most of previous studies on regional economic development are based on the statistics collected typically in administrative units. This paper has analyzed the defects of traditional studies, and attempted to research regional economic development problems with 10-year DMSP/OLS nighttime light satellite imagery as a new data source. For exploring the relationship between DMSP/OLS nighttime light data and GDP, different types of curve fitting regression models have been tried, the Cubic model has shown the best performance with a coefficient of determination (R2) equal to 0.803. Based on this positive correlation, we have estimated provincial economic development level of China using DMSP/OLS nighttime light data. The research results have indicated that the DMSP/OLS nighttime light data can well reveal provincial economic development levels.

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