scholarly journals An energy and exergy analysis of photovoltaic system in Bantul Regency, Indonesia

2018 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Arif Rahman Hakim ◽  
Wahyu Tri Handoyo ◽  
Putri Wullandari
Keyword(s):  
Energy Efficiency ◽  
Exergy Analysis ◽  
Environmental Temperature ◽  
Exergy Efficiency ◽  
Photovoltaic System ◽  
Pv System ◽  
High Solar Radiation ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Special Region

Energy and exergy analysis has been conducted on photovoltaic (PV) system in Bantul Regency, a special region of Yogyakarta, Indonesia. The PV exergy analysis was used to determine the performance of the PV system by considering environmental factors other than solar irradiance. This research aims to obtain values of exergy and energy efficiencies in the PV system. The experiment results show that the energy efficiency value produced by the PV system was 8.62–74.18%, meanwhile its exergy efficiency was 0.29%-9.40%, respectively. The value of exergy efficiency is lower than the value of energy efficiency. This result confirmed that the environmental factor greatly affects the output of the PV system. It can be concluded that high solar radiation does not always increase the production of exergy, since it is also influenced by the environmental temperature and the PV cells' temperature.

scholarly journals Performance Evaluation of a Full-Scale Fused Magnesia Furnace for MgO Production Based on Energy and Exergy Analysis

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 214
Author(s):  
Tianchi Jiang ◽  
Weijun Zhang ◽  
Shi Liu
Keyword(s):  
Energy Efficiency ◽  
Mass Transport ◽  
Exergy Analysis ◽  
Exergy Efficiency ◽  
Smelting Process ◽  
Exergy Destruction ◽  
Electric Power Supply ◽  
Flow Energy ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis

A three-electrode alternating current fused magnesia furnace (AFMF) with advanced control technology was evaluated by combined energy and exergy analysis. To gain insight into the mass flow, energy flow and exergy efficiency of the present fused magnesia furnace, the exergy destruction was analysed to study the energy irreversibility of the furnace. Two different production processes, the magnesite ore smelting process (MOP) and light-calcined magnesia process (LMP), are discussed separately. Two methods were carried out to improve LMP and MOP; one of which has been applied in factories. The equipment consists of an electric power supply system, a light-calcined system and a three-electrode fused magnesia furnace. All parameters were tested or calculated based on the data investigated in industrial factories. The calculation results showed that for LMP and MOP, the mass transport efficiencies were 16.6% and 38.3%, the energy efficiencies were 62.2% and 65.5%, and the exergy destructions were 70.5% and 48.4%, respectively. Additionally, the energy efficiency and exergy efficiency of the preparation process of LMP were 39.4% and 35.6%, respectively. After the production system was improved, the mass transport efficiency, energy efficiency and exergy destruction were determined.

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

Energy and Exergy Analysis of Solar Parabolic Dish Thermoelectric Generator

2014 ◽  
Vol 592-594 ◽  
pp. 2437-2441 ◽  
Author(s):  
Gunalan Muthu ◽  
Subramaniam Shanmugam ◽  
Arunachalam R. Veerappan
Keyword(s):  
Energy Efficiency ◽  
Concentration Ratio ◽  
Thermoelectric Generator ◽  
Exergy Analysis ◽  
Exergy Loss ◽  
Thermal System ◽  
Increase With Increase ◽  
Energy And Exergy ◽  
Parabolic Dish ◽  
Energy And Exergy Analysis

The Performance of a thermal system is generally analysed by carrying out energy and exergy analysis of its different subsystems. In the present study the performance of subsystem namely PDC, receiver plate and PDC in a system of solar parabolic dish thermoelectric generator is studied. It is found that the energy and exergy loss are minimum in the receiver plate as compared to PDC and thermoelectric generator (TEG) at a particular direct normal irradiation (DNI). The exergy and energy efficiency in the PDC and TEG increase with increase in concentration ratio.

scholarly journals Energy and exergy analysis of air based photovoltaic thermal (PVT) collector: a review

2019 ◽  
Vol 9 (1) ◽  
pp. 109 ◽  
Author(s):  
Ahmad Fudholi ◽  
Mariyam Fazleena Musthafa ◽  
Abrar Ridwan ◽  
Rado Yendra ◽  
Ari Pani Desvina ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Flat Plate ◽  
Solar Collector ◽  
Exergy Analysis ◽  
Exergy Efficiency ◽  
Pv Panel ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Flat Plate Solar Collector

<span lang="EN-US">Photovoltaic thermal (PVT) collectors convert solar radiation directly to both electrical and thermal energies. A PVT collector basiccaly combines the functions of a flat plate solar collector and those of a PV panel. This review presents thermodinamics fundamentals, descriptions, and previous works conducted on energy and exergy analysis of air based PVT collector. Studies in 2010 to 2018 of the energy and exergy analysis of air based PVT collectors are summarized. The energy and exergy efficiency of air based PVT collector ranges from 31% to 94% and 8.7% to 18%, respectively. In addition, flat plate solar collector is presented. Studies conducted on air based PVT collectors are reviewed.</span>

scholarly journals Performance of 20w Solar Photovoltaic Module for Energy and Exergy Analysis

2021 ◽  
Vol 7 (05) ◽  
pp. 102-106
Author(s):  
Rajendra. G, Sai Ranjith Reddy.K and Ganesh Kumar. I.R S. Yoga Sainath Reddy, Jagannath Reddy
Keyword(s):  
Exergy Analysis ◽  
Short Circuit ◽  
Photovoltaic System ◽  
Energy Output ◽  
Photovoltaic Module ◽  
Solar Photovoltaic ◽  
Solar Pv ◽  
Solar Module ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis

The solar photovoltaic system generates both thermal energy and electrical energy by utilizing solar energy. In this paper an experimental attempt has made for calculating energy output as well as exergy output of solar PV panel installed at R.L.J.I.T. Bangalore. Energy and exergy analysis was performed by using first and second law of thermodynamics to evaluate energy and exergy. The framework involved in this process are ambient temperature, overall heat transfer, open-circuit voltage, short-circuit current, fill factor, solar radiations etc. It is predicted that temperature of pv solar module has most effect on the efficiencies. By the help of water or air the heat can be removed to improve both energy and exergy efficiencies.

scholarly journals ENERGY AND EXERGY ANALYSIS OF A CYLINDRICAL HOT WATER STORAGE TANK: EXPERIMENTAL AND CFD ANALYSIS

2020 ◽  
Author(s):  
Tomas Kropas ◽  
Giedrė Streckienė
Keyword(s):  
Numerical Model ◽  
Storage Tank ◽  
Exergy Analysis ◽  
Water Storage ◽  
Exergy Efficiency ◽  
Hot Water ◽  
Water Storage Tank ◽  
Environment Temperature ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis

Active solar water heating systems typically include hot water storage tanks. The selection of the storage system strongly affects the performance of the entire system. This article presents a detailed analysis of a hot water storage tank during charging and dynamic charging-discharging mode. A numerical model using computational fluid dynamics for the storage tank was developed to investigate the temperature distribution inside of it. Transient thermal analysis was carried using ANSYS Fluent. The numerical model was validated with the experimental results. The energy and exergy analysis as an important tool for the evaluation of the thermal systems quantitatively and qualitatively was performed. The calculation procedures were described. The energy and exergy efficiencies, heat losses were calculated for steady and dynamic processes. Effect of mass flow rate was analysed. The results from parametric analysis showed that charging dynamics reduced the thermocline and efficiency of the hot water storage tank. The dependency of the exergy efficiency of the heat storage tank on the reference environment temperature during the dynamic operation was analysed. Exergy efficiencies for two cities with different climates were compared. This indicated that the higher envi-ronmental temperature gave lower exergy efficiency of the storage tank.

scholarly journals Energy and Exergy Analysis of an Indirect-Mode Natural Convection Solar Dryer for Maize

2021 ◽  
Vol 11 (2) ◽  
pp. 19
Author(s):  
Isaac N. Simate
Keyword(s):  
Natural Convection ◽  
Exergy Analysis ◽  
Exergy Efficiency ◽  
Solar Simulator ◽  
Solar Dryer ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Maize Grain ◽  
Internal Irreversibility ◽  
Drying Chamber

The energy and exergy analysis of an indirect-mode natural convection solar dryer for maize grain is presented. Two different sizes of maize grain bed depths of 0.04 m and 0.02 m translating into grain loads of 10 kg and 5 kg respectively, are used in the study to determine their effects on the collector energy and exergy efficiencies and the drying chamber exergy efficiency. Experiments were carried out using an indirect-mode laboratory solar dryer under a solar simulator with a radiation setting of 634.78 W/m2. The analysis gave average collector energy efficiencies of 33.3 % and 46.2 % for the 10 kg and 5 kg loads, respectively, which are higher than the collector exergy efficiencies of 2.4 % and 2.6 % for the 10 kg and 5 kg loads, respectively. The drying chamber exergy efficiencies are 45.2 % and 28.4 % for the 10 kg and 5 kg loads, respectively. In view of this, the 5 kg load is considered to be more efficient at extracting energy from the collector due to higher air flow resulting from its relatively thin grain bed depth of 0.02 m, but less efficient in utilising the extracted energy to evaporate moisture from the grain which has resulted in a lower drying chamber exergy efficiency. Further, the exergy loss in the drying chamber for the 5 kg load is higher than that in the 10 kg load as 72.3 % of the exergy entering the drying chamber is lost through emissions as well as destroyed through internal irreversibility compared to 57.0 % for the 10 kg load.&nbsp;

Review on Energy and Exergy Analysis of Air and Water Based Photovoltaic Thermal (PVT) Collector

2018 ◽  
Vol 9 (3) ◽  
pp. 1366
Author(s):  
Muslizainun Mustapha ◽  
Ahmad Fudholi ◽  
Chan Hoy Yen ◽  
Mohd Hafidz Ruslan ◽  
Kamaruzzaman Sopian
Keyword(s):  
Thermal Energy ◽  
Energy Demand ◽  
Exergy Analysis ◽  
High Energy ◽  
Exergy Efficiency ◽  
Space Heating ◽  
Domestic Water ◽  
Energy And Exergy ◽  
Water Based ◽  
Energy And Exergy Analysis

<p class="AEuroAbstract">In photovoltaic thermal hybrid (PV/T) collectors, the electricity and thermal energy are produce simultaneously. PV/T technology has been proven in previous studies where it could give benefits for high energy demand supplementary. For example, in space heating, domestic water heating and also drying. The PVT collectors can be classified into air-based PVT, water-based PVT and dual-fluid (air+water) PVT collector. In this paper, the analysis of energy and exergy efficiency of PVT collectors are compiled and reviewed. This study has found that generally the energy and exergy efficiency are range from 40%-70% and 5%-20%, respectively.</p>

scholarly journals Energy and Exergy Analysis of LiBr-aq and LiCl-aq Liquid Desiccant Dehumidification System

2020 ◽  
Vol 14 (1) ◽  
pp. 36-40
Author(s):  
Barış KavasoğullarI ◽  
Ertuğrul Cihan ◽  
Hasan Demir
Keyword(s):  
Exergy Analysis ◽  
Lithium Bromide ◽  
Exergy Efficiency ◽  
Coefficient Of Performance ◽  
Airflow Rate ◽  
Liquid Desiccant ◽  
Energy And Exergy ◽  
Liquid Desiccant Dehumidification ◽  
Energy And Exergy Analysis ◽  
Mass Flow Rates

In this study, energy and exergy analysis of experimental results obtained from a dehumidification system using LiBr-aq (lithium bromide-water) and LiCl-aq (lithium chloridewater) as desiccant was made. In dehumidifier and regenerator columns polycarbonate sheets, which have not been used before, were used as packing material to increase contact area in purposed liquid desiccant dehumidification system. In the analysis, variation of electrical coefficient of performance and exergy efficiency with airflow rate for different solution mass flow rates were investigated. Because of investigation, maximum values of electrical coefficient of performance and exergy efficiency were calculated approximately as 2.8 and 18%, respectively.

scholarly journals Energy and Exergy Analysis of the Air Source Transcritical CO2 Heat Pump Water Heater Using CO2-Based Mixture as Working Fluid

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4470
Author(s):  
Yikai Wang ◽  
Yifan He ◽  
Yulong Song ◽  
Xiang Yin ◽  
Feng Cao ◽  
...  
Keyword(s):  
Exergy Analysis ◽  
Heat Pumps ◽  
Exergy Efficiency ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Domestic Hot Water ◽  
Practical Applications ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis

Given the large demand nowadays for domestic hot water, and its impact on modern building energy consumption, air source transcritical CO2 heat pumps have been extensively adopted for hot water production. Since their system efficiency is limited by significant irreversibility, a CO2-based mixture could offer a promising drop-in technology to overcome this deficiency without increasing system complexity. Although many CO2 blends have been studied in previously published literature, little has been presented about the CO2/R32 mixture. Therefore, a proposed mixture for use in transcritical CO2 heat pumps was analyzed using energy and exergy analysis. Results showed that the coefficient of performance and exergy efficiency variation displayed an “M” shape trend, and the optimal CO2/R32 mixture concentration was determined as 0.9/0.1 with regard to flammability and efficiency. The irreversibility of the throttling valve was reduced from 0.031 to 0.009 kW⋅kW−1 and the total irreversibility reduction was more notable with ambient temperature variation. A case study was also conducted to examine domestic hot water demand during the year. Pure CO2 and the proposed CO2 blend were compared with regard to annual performance factor and annual exergy efficiency, and the findings could provide guidance for practical applications in the future.

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