Materials and Energy Research Center (MERC)
Iranian Association of Chemical Engineers (IAChE)
Journal of Renewable Energy and Environment
2423-5547
2423-7469
4
1
2017
02
01
Theoretical Investigation of Consumption Patterns Effect on Optimal Orientation of Collector in Solar Water Heating System
1
10
EN
Abbas
Rajabi Khanghahi
Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran
Mohammad
Zamen
Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran
Mehdi
Soufari
Iranian Institute R&D in Chemical Industries (ACECR), Karaj, Iran
Majid
Amidpour
0000-0003-2073-6106
Department of Mechanical Engineering, K.N. Toosi University of Technology, Tehran, Iran
amidpour@kntu.ac.ir
Ali
Abbas Nejad
Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran
10.30501/jree.2017.70101
One of the subjects in solar water heater design is considering distribution of hot water consumption during the day. For example, each of the household, commercial, office, school, and industrial consumptions have a particular distribution of hot water consumption named pattern in this article. In solar computation principles, the effect of longitude, latitude, and altitude on collector angle has been clearly presented. However, the effect of consumption pattern especially on the collector orientation has been rarely investigated. The aim of the current study is to survey the effect of various consumption patterns on the collector’s orientation and tilt angle and so calculation of related energy saving. So, five common patterns including office building, commercial building, afternoon and morning shift high school and a 15-unit apartment have been studied and optimal surface azimuth angle and tilt angle determined. It has been observed that 11 to 14 % energy saving can be archived by selecting the optimal angles with respect to hot water consumption pattern in comparison to a state that collectors are orientated for maximum reception of solar energy. Also effect of solar fraction, storage volume and amount of hot water consumption are studied and discussed.
Solar Water Heater,Consumption Pattern,Collector orientation,tilt angle,Azimuth angle
https://www.jree.ir/article_70101.html
https://www.jree.ir/article_70101_a6d4969bc61fa9fe0840808dc8859eef.pdf
Materials and Energy Research Center (MERC)
Iranian Association of Chemical Engineers (IAChE)
Journal of Renewable Energy and Environment
2423-5547
2423-7469
4
1
2017
02
01
Optimization of Solar Absorption Cooling System Considering Hourly Analysis
11
19
EN
Zahra
Hajabdollahi
Department of Energy and Power Engineering, Huazhong University of science and technology, Wuhan, China
Majid
Sedghi Dehnavi
School of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran
Hassan
Hajabdollahi
Department of Mechanical Engineering, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran
10.30501/jree.2017.70102
Thermal modelling and optimal design of a solar absorption cooling system are presented, and hourly analysis is performed over the period of a year. Three design parameters are considered, then the Real Parameter Genetic Algorithm (RPGA) is applied to obtain the minimum total annual cost. The optimization results show that the solar cooling optimum configuration needs 1630 square meter collectors, a storage tank with a 15000L capacity as well as an absorption chiller with 300kW capacity. The hourly analysis shows that the space temperature fluctuates on average every 62 minutes during June and decreases to 51 minutes in September. In addition, the optimum number of collectors increases 26.67% given a 50% increment in electricity price while it decreases 20% given a 50% decrement in electricity price. Finally a sensitivity analysis on RPGA parameters is performed and results are reported.
Solar absorption cooling system,Hourly analysis,Total annual cost,Real Parameter Genetic Algorithm,Decision variables
https://www.jree.ir/article_70102.html
https://www.jree.ir/article_70102_d85d3522e290bc105728537e109bd74d.pdf
Materials and Energy Research Center (MERC)
Iranian Association of Chemical Engineers (IAChE)
Journal of Renewable Energy and Environment
2423-5547
2423-7469
4
1
2017
02
01
Different Types of Pitch Angle Control Strategies Used in Wind Turbine System Applications
20
35
EN
Ehsan
Hosseini
0000-0003-4693-9008
Department of Electrical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran.
ehsanhosseini.690@gmail.com
Ghazanfar
Shahgholian
0000-0003-2774-4694
Department of Electrical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran
shahgholiangh@gmail.com
10.30501/jree.2017.70103
The most common controller in wind turbine is the blade pitch angle control in order to get the desired power. Controlling the pitch angle in wind turbines has a direct impact on the dynamic performance of the machine and fluctuations in the power systems. Due to constant changes in wind speed, the wind turbines are of nonlinear and multivariate system. The design of a controller that can adapt itself with the system, at any given time, is of crucial importance. To limit the aerodynamic power gained from the wind turbine in the high wind speed areas, different methods has are applied on pitch angle. In this paper an extensive literature review on pitch angle control technique in wind turbine has been highlighted. Classical and adaptive controllers, structure control, robust control and intelligent control are among the control methods adopted in this study. In comparison of the controllers, although adaptive and robust controllers, with less sensitivity to changes in environmental conditions, outperform the classic controller, the intelligent controller system presents the best performance of the wind turbines through estimating the system variables and appropriate adaptation to changes at the operating point.
wind turbines,blade pitch angle control,maximum power tracking,controller
https://www.jree.ir/article_70103.html
https://www.jree.ir/article_70103_1db1f11ead7e784b7ae97b2eaff1ff96.pdf
Materials and Energy Research Center (MERC)
Iranian Association of Chemical Engineers (IAChE)
Journal of Renewable Energy and Environment
2423-5547
2423-7469
4
1
2017
02
01
Thermal Pretreatment for Improvement of Biogas Production and Salinity Reduction by Zeolite
36
40
EN
Rozita
Asgari
Faculty of Agriculture and Natural Resources, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran
Farida
Iraji Asiabadi
Water Research Center, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran
f.irajy@khuisf.ac.ir
Hadi
Radnezhad
Faculty of Agriculture and Natural Resources, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran
10.30501/jree.2017.70104
The anaerobic digestion of organic waste for biogas production can be affected by some variables such as temperature; concentration of the biogas feed solution, bacteria populations, and pressure. This study investigated the effects of thermal pretreatment at 50, 75, and 100 ºC on the biogas produced by simultaneous anaerobic digestion of cow manure, mushroom waste, and wheat straw at thermophilic temperature. Moreover, the effects of a zeolite on reducing the salinity of the wastewater were evaluated. Cow manure, mushroom waste, and wheat straw were mixed to yield a mixture with an optimum carbon to nitrogen ratio of 20-30 and TS of 25-35%. Each thermal pretreatment was prepared in four replicates and placed in a steam bath with a temperature of 55 ºC. The amount of gas produced by each thermal pretreatment was measured every day for 15 days. On day 15, the electrical conductivity of the produced wastewater was measured and the wastewater was exposed to a modified zeolite. The results showed that the greatest level of biogas was produced by thermal pretreatment at 75 ºC, which gave the biogas yield of 0.197 L/gVS after 15 days observation while, the other thermal pretreatments at 50, and 100 ºC gave the biogas yield 0.147, and 0.169 L/gVS, respectively. The highest amount of biogas was achieved on the third day for every three thermal pretreatments. Moreover, the modified zeolite reduced the wastewater salinity by 25%. These results confirmed that thermal pretreatment at 75 ºC is an effective pretreatment for biogas production improvement from the mixture of cow manure, mushroom waste, and wheat straw, and the modified zeolite could be used for salinity reduction of wastewater discharged from the process.
Biogas,Thermal pretreatment,Wastewater,Zeolite
https://www.jree.ir/article_70104.html
https://www.jree.ir/article_70104_a39ff3b0074d60a0ee9e053c6495c83f.pdf
Materials and Energy Research Center (MERC)
Iranian Association of Chemical Engineers (IAChE)
Journal of Renewable Energy and Environment
2423-5547
2423-7469
4
1
2017
02
01
Effect of Temperature on Electrical Parameters of Phosphorous Spin–on Diffusion of Polysilicon Solar Cells
41
45
EN
Siamak
Azimi-Nam
Department of Advanced Materials and Renewable Energy, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran
Foad
Farhani
Department of Mechanical Engineering, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran
f.farhani@irost.ir
10.30501/jree.2017.70105
Effects of temperature on electrical parameters of polysilicon solar cells, fabricated using the <br />phosphorous spin-on diffusion technique, have been studied. The current density–voltage<br />characteristics of polycrystalline silicon solar cells were measured in dark at different temperature<br />levels. For this purpose, a diode equivalent model was used to obtain saturation current densities<br />measured at the required temperatures. The experimental results showed that the increase in<br />temperature from 27 to 70˚C produced a rapid increase in the saturation current densities from 0.00003<br />to 0.0005A. The changes in the open circuit voltage and the short circuit current density were found to<br />be linear with the temperature variations: about 3 mV/˚C reduction in the open circuit voltage was<br />observed. Measurements of the short circuit current density revealed a very small dependency of the<br />current density on the temperature variations. Accordingly, the short circuit current density increased<br />from 17.8 to 18.4 mA with increase in temperature from 27 to 107˚C. Measurements of the output<br />power versus load resistance were obtained at different temperature levels. The results showed that the<br />output power dropped by 30% with temperature rise from 27 to 107˚C.
Temperature effect,reverse saturation current,open circuit voltage,Short Circuit Current,Output Power,polysilicon solar cell
https://www.jree.ir/article_70105.html
https://www.jree.ir/article_70105_08c49abfb6019aa4d7f0c12b508a998d.pdf
Materials and Energy Research Center (MERC)
Iranian Association of Chemical Engineers (IAChE)
Journal of Renewable Energy and Environment
2423-5547
2423-7469
4
1
2017
02
01
An overview of organic/inorganic membranes based on sulfonated poly ether ether ketone for application in proton exchange membrane fuel cells
46
60
EN
Somayeh
Sarirchi
Department of Chemical Engineering, Iran University of Science and Technology, Tehran, Iran
S.
Rowshanzamir
Department of Chemical Engineering, Iran University of Science and Technology, Tehran, Iran
rowshanzamir@iust.ac.ir
10.30501/jree.2017.70106
Nowadays, proton exchange membrane fuel cells (PEMFCs) are the most promising green energy <br />conversion devices for portable and stationary applications. Traditionally, these devices were based on<br />perfluoro-sulfonic acid electrolytes membranes, given the commercial name Nafion. Nafion is the most<br />used electrolyte membrane till now; because of its high electrochemical properties such as high proton<br />conductivity, good mechanical and chemical stability at fuel cell conditions, and .... However, its high <br />cost, reducing the performance at temperature higher than 80℃, and low humidity are the major<br />problems. Hydrocarbon polymers are encouraging alternative to Nafion, since they show the same or<br />even superior performance than Nafion at high temperature and low humidity by some modifications. <br />Numerous researches confirmed that Sulfonated poly ether ether ketone (SPEEK) is a promising PEM<br />because of its low-cost, low fuel cross over, and acceptable thermo-mechanical stabilities. However,<br />suitable proton conductivity in SPEEKs is depending on the high degree of sulfonation (DS), which<br />could deteriorate the mechanical properties of SPEEK membranes progressively at the high level. To<br />overcome this dilemma, various SPPEK-based hybrid/blend membranes are synthesized, and the<br />effects of the introduced fillers on their performance are investigated. The introduced inorganic<br />particles to the polymer membranes might be silica, zirconia, titania, heteropolyacids, carbon<br />nanotubes, and.... Enhanced proton conductivity, water retention at high temperatures, and higher<br />electrochemical properties are mentioned as some advantages of incorporating inorganic material into<br />the polymer matrix. High thermo-mechanical resistance and electrochemical activities are supplied by<br />inorganic moieties, while the organic parts supply plasticity and easier ductility at the low temperature.<br />Indeed, SPEEK blends have a good potential to alter Nafion at the high temperature and/or relatively<br />low humidity. In this paper, the last advances in progress of SPEEK-based organic/inorganic<br />composite membranes that perform truly under fuel cell conditions are discussed.
Fuel Cell,poly ether ether ketone,Nanocomposite,Membrane
https://www.jree.ir/article_70106.html
https://www.jree.ir/article_70106_82e054b63ad6d51e81d13ac15fbdf978.pdf
Materials and Energy Research Center (MERC)
Iranian Association of Chemical Engineers (IAChE)
Journal of Renewable Energy and Environment
2423-5547
2423-7469
4
1
2017
02
01
Evaluation of Off-grid Hybrid Renewable Systems in the Four Climate Regions of Iran
61
70
EN
Shoeleh
Vahdatpour
Department of Architecture, Sepehr institute of Higher Educational
Shokoofeh
Behzadfar
Department of Architecture, Sepehr institute of Higher Educational
Leila
Siampour
Department of Architecture, Sepehr institute of Higher Educational
Elahe
Veisi
Department of Architecture, Sepehr institute of Higher Educational
Mehdi
Jahangiri
0000-0001-6803-8804
Department of Mechanical Engineering, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran.
jahangiri.m@iaushk.ac.ir
10.30501/jree.2017.70107
Renewable systems influence the process of supplying domestic electricity demands. It will be useful to replace the conventional energy generation system by renewable energy sources since the uncontrolled use of fossil fuels is accompanied by global warming and environmental hazards, in addition to the danger of their depletion, and because most of the energy derived from these fuels are used in buildings. Economical renewable energy systems have not yet been studied in each climate of Iran. Considering the historical background and the potential biomass of Iran, the potential of using a hybrid solar cell/wind turbine/biomass system for supplying the electricity demands of a residential building in each of the four climate regions of Iran has been studied by using HOMER software in this paper. HOMER software has been determined the most cost-efficient system for each region by using the solar radiation and wind speed data, which are acquired over 20 years. By considering economic issues, results indicate that usage of solar cells is the ideal option for the cold, hot dry and warm humid climates (Total net present cost (NPC) and cost of electricity (COE) are $11639 and 1.808 $/kWh, respectively). Also, usage of systems based on biomass is the best choice for the moderate and humid climates (total NPC and COE are $13211 and 2.052 $/kWh, respectively for Babol and $13075 and 2.031 $/kWh, respectively for Chalous).
Biogas,Battery,converter,cost of energy (COE),total net present cost (Total NPC)
https://www.jree.ir/article_70107.html
https://www.jree.ir/article_70107_75dbc7df65cf21502d4ca1c3531d0e9b.pdf