دانشگاه شهيد باهنركرمان
|Since 2015||All||Google Scholar|
دانشگاه شهيد باهنركرمان
گروه آموزشی مکانیک
گروه آموزشی مکانیک
A hybrid (photovoltaic, PV/wind/fuel cell, FC) system comprising different combinations of PV arrays, wind turbine, hydrogen tank, electrolyser, and FC has been investigated for stand-alone applications. Load demand was the electrical requirements of atypical residential apartment having a total area of 500 m2 with a peak electrical load of 35 kW and a yearly load of 24.4 MWh in Kerman, Iran. The assessment criterion for the analysis was levellised cost of energy of each system configuration. National Renewable Energy Laboratory\\\'s Hybrid Optimization Model for Electric Renewable software was utilized as the assessment tool of the present study. The effect of electrical load profile on the optimization results has also been investigated considering a demand load profile with a low peak of 12 kW. Also, a comparison was made between the hybrid (PV/wind/diesel/bat) systems and the hybrid (PV/wind/FC) system of the current study at different fuel price scenarios.
This paper presents a hybrid power generation system comprising of Photovoltaic (PV) panels, Molten Carbonate Fuel Cell (MCFC), Gas Turbine (GT), Thermal Energy Storage (TES), Battery (Bat) and a Compressed Air Energy Storage (CAES) system. The CAES pressure was considered to be regulated using a water reservoir system located at a suitable height place. The described system was designed to supply the electricity needs of 500 households with peak electricity demand of 500kW. A set up MCFC/GT with power generation rate of 500kW was considered in the calculations, and the PV system capacity was considered to be changed from 100kW to 600kW. The optimal configuration and operational conditions of the system were conducted based on the Levelized Cost of Electricity (LCOE) definition as well as the total annual emission that is occurred by the auxiliary fossil fuel boiler and MCFC systems. The results showed that the overall system efficiency would be increased by about 25%, when the CAES is used and the compressor is switched off. Also, the optimal operational pressure of MCFC was found to be 6bar for 2000 number of PVs, 1500kWh of battery storage and CAES capacity of 685m3.
Water and power cogeneration systems have been received more attention in recent years. In the present research, in addition to techno-economic investigation of the integration of multiple effect desalination/thermal vapor compression (MED/TVC) system and reverse osmosis (RO) system into the gas turbine (GT) power cycle, the GT/MED-TVC/RO configuration is also proposed. At first, the models used for GT, MED-TVC and RO systems are validated with the experimental data in the literature and good correspondence is found. In this study, the effect of air temperature on the GT stack outlet gases and the effect of seawater temperature on the MED-TVC GOR are investigated. Moreover, using the RO energy analysis, the most suitable RO membrane is selected by considering the permeate quality and membrane price. Then, the LCOE and LCOW for three scenarios of GT/ MED-TVC with 5000 m3 /d, GT/RO with 5000 m3 /d, and GT/MED-TVC/RO with MED-TVC and RO water production rates of 2000 m3 /d and 3000 m3 /d, respectively are determined. The results of the economic analysis in three scenarios showed that the least electricity cost and the least freshwater production cost belong to GT/MED-TVC and GT/RO configurations, respectively. Furthermore, the effect of number of stages of the MED-TVC system on the energy and economy of the GT/MED-TVC/ RO configuration is explored. It was observed that increasing the number of effects from 4 to 7 has no tangible effect on the LCOE. In addition, the output temperature and concentration of GT/MED- TVC/RO plant at different number of MED-TVC effects is determined. Finally, the effect of fuel cost and desalination system scale on the LCOW and LCOE at three configurations are investigated.
The present paper deals with a comparative exergo-economic analysis among four different horizontal Direct-Ex- pansion Geothermal Heat Pumps (DX-GHP) with Carbon Dioxide ( ) refrigerant in transcritical cycle. The stud- ied configurations include the cycle with (a) expansion valve (EVC), (b) with expander (EC), (c) with expansion valve and Internal Heat Exchanger (EVC+IHE), and (d) with expander and IHE (EC+IHE). The unit cost of heat ($/ ) for each configuration was determined under two scenarios of a) constant Space Heating (SH) and b) constant Domestic Hot Water (DHW) loads with the peak of 8kW. The results showed that the lowest unit cost of heat ( ) and the highest total exergy efficiency ( ) are associated with the (EVC+IHE) and (EC+IHE) config- urations, respectively. Also, it was shown that for the SH (or DHW) load, 20% (or 14%) increase in the results in 21.5% (or 20%) increase in the considering the electricity cost of 0.025 $/kWh. For the electricity cost of 0.25$/kWh, however, 11% (or 20%) increase in results in increasing the by about 7% (or 13%). It was also concluded that the configuration with the highest is not that with the lowest .
چکیده در این تحقیق، تحلیل ترمودینامیکی و ترمواکونومیکی سیستم ترکیبی مبدل حرارتی جذبی، چرخه رانکین آلی و آبشیرینکن اسمز معکوس با هدف تولید الکتریسیته و آب شیرین از منابع دما پایین انجام شده است. کلیه آنالیزها براساس قوانین ترمودینامیک و ترمواکونومیک میباشد. نتایج نشان میدهند که در سیستم مبدل حرارتی جذبی با دستیابی به ضریب عملکرد 4372/0 مقدار 7/494 کیلووات انرژی حرارتی در ابزوربر حاصل میشود که دمای آن تا 105 درجه سلسیوس افزایش مییابد. با انتقال این مقدار حرارت به سیستم رانکین آلی، مقدار 18/63 کیلووات الکتریسیته تولید میشود. با مصرف این مقدار الکتریسیته در سیستم اسمزمعکوس، 2/216 مترمکعب در روز آب شیرین تولید میگردد که هزینه این مقدار آب تولید شده 217/2 دالر به ازای هرمترمکعب بهدست میآید. همچنین در تحلیل ترمواکونومیک مقدار هزینه برواحد اگزرژی تمام نقاط سیستم و هزینه الکتریسیته و آب تولید شده محاسبه شد. در ادامه مقدار هزینه تراز شده الکتریسیته در نرخهای حرارت اتالفی مختلف مورد بررسی قرار گرفته، براساس نتایج با افزایش مقدار نرخ حرارت، هزینه تراز شده الکتریسیته کاهش مییابد. همچنین تاثیر تغییرات هزینهسرمایهگذاری هر سیستم و نرخ بهره واقعی برروی هزینه آب شیرین تولید شده مورد مطالعه قرار گرفته است.
Two solar polygeneration systems were investigated for electricity, cooling and fresh water production. In the first scenario (LFPS), the linear Fresnel (LF) solar field was used as thermal source of the Organic Rankine Cycle (ORC), absorption chiller (ACH) and multi-effect desalination (MED) unit. In the second scenario (PVPS), photovoltaic (PV) panels were considered as the electricity source to supply the electricity load that is required for lighting, electrical devices, compression chiller (CCH) and reverse osmosis (RO) units. A techno-economic comparison was made between two scenarios based on the land use factor (F), capacity utilization factor (CUF), payback period, levelized cost of electricity (LCE), levelized cost of cooling energy (LCC) and levelized cost of water (LCW). The calculations were conducted for four different locations in order to determine the effect of solar radiation level on the LCE, LCC and LCW of systems in both scenarios. The results showed that the LCE and LCW of PVPS is lower than that of LFPS and the LCC of LFPS is lower than that of PVPS. Also, the payback period of LFPS and PVPS systems are obtained as 13.97 years and 13.54 years, respectively, if no incentive is considered for the electricity sale.
در این مقاله مقایسهای بین چهار پمپ حرارتی منبع زمینی انبساط مستقیم افقی دیاکسیدکربن با بهرهگیری از تحلیل ترمواکونومیک انجام گرفته است. برای چهار سیستم مورد بررسی، هزینه تولید هر واحد حرارت در بار گرمایشی برابر با 8 کیلووات در دو حالت گرمایش محیط و آبگرم مصرفی مورد محاسبه قرار گرفته است. مطابق با نتایج بدست آمده، سیستم دارای شیر انبساط به همراه مبادلهکنحرارتی داخلی و سیستم دارای منبسطکننده به همراه مبادلهکنحرارتی داخلی به ترتیب کمترین هزینه هر واحد حرارت تولید شده و بیشترین ضریب عملکرد را دارا میباشند. علاوه بر این مشخص گردید که به ترتیب در دو حالت گرمایش محیط و آبگرم مصرفی، 19 و 11 درصد افزایش ضریب عملکرد منجر به 11 و 5/7 درصد افزایش هزینه هر واحد حرارت تولید شده در قیمت برق 025/0 دلار بر کیلووات ساعت میگردد. همچنین برای درصدهای افزایشی ضریب عملکرد اشاره شده و با درنظر گرفتن قیمت برق 25/0 دلار بر کیلووات ساعت، در دو حالت گرمایش محیط و آبگرم مصرفی، هزینه هر واحد حرارت تولید شده در حدود 6 درصد افزایش مییابد.
In this article, the application of a hybrid phosphoric acid fuel cell and organic Rankine cycle (PAFC/ORC) system was thermo-economically investigated for sulfuric acid production in Sarcheshmeh copper complex (SCC); the second largest copper deposit worldwide. The electricity that is produced by the sys- tem is consumed by electrolyzer to produce the hydrogen and sulfuric acid. Two scenarios were considered for applying the PAFC thermal energy as ther- mal source of the ORC to produce further power. The performance of the sys- tem was investigated considering various important parameters such as organic fluid type, PAFC current density (IPAFC), fuel & air consumption fac- tors as well as the ORC turbine inlet pressure (Pi, ORC). The unit cost of sulfuric acid and the hybrid system simple payback period were obtained as 0.0215 $/kg and 3.65 years, respectively.
The previous research works have proven that the location of the thermal vapor compression (TVC) plays an important role on the performance of the multi effect desalination (MED) plant. The objective of this paper is to investigate the effects of different design parameters such as TVC location, motive steam pressure, seawater temperature, number of effects (Neffs), and heating steam temperatures on gain output ratio (GOR), specific energy consumption and exergy efficiency (ηex) of the system. Since wide ranges of design parameters were considered, the results are helpful for primary design and best operation modes of the MED/TVC plant when it is located at different places across the world. The results revealed that for each Neffs, there is an optimal location for TVC to obtain the maximum GOR, maximum ηex, and minimum specific heat transfer area (SA). For lower Neffs, the optimum TVC location is less affected by motive steam pressure. However, by increasing the Neffs, the optimum TVC location is shifted to the upper effects. Also, the ηex and SA were shown to be changed between 3.5% and 7%, and 450 and 900 m2/(kg/s), respectively.
The thermodynamic analysis of a horizontal CO2 direct-expansion ground source heat pump in transcritical cycle was performed to investigate the influence of using thermoelectric sub-cooler and the ejector on the performance parameters of the cycle. A comparative analysis was conducted between the Base cycle and the cycles with ejector and thermoelectric sub-cooler considering the pressure drops in the gas cooler and the ground heat exchanger. The effects of compressor inlet temperature, soil temperature, thermoelectric sub-cooler length, thermoelectric sub-cooler cooling water mass flow rate, and ground heat exchanger outlet temperature on different performance parameters of the cycles were studied. The results demonstrated that the application of ejector exhibits a more stable operation of the cycle and increasing its COP by 16.5% as compared to the Base cycle considering the same ground heat exchanger length. Also, the length of ground heat exchanger is considerably decreased by using the ejector considering the same COP for the Base and EJR cycles. Besides, thermoelectric sub-cooler decreases the irreversibilities of the cycle by generation more power, thereby COP is boosted by 16% as compared to the Base cycle. Furthermore, the major irreversibility in the cycle with thermoelectric and ejector is occurred in the compressor and followed by ejector, ground heat exchanger, gas cooler, thermoelectric sub-cooler, and the expansion valve, respectively.
The application of splitters has been proven to be useful to control the separated wake downstream of the pin-fins. This paper aims to evaluate the thermal () and frictional () irreversibility rates in the fluid flow inside the plate-pin-fin heatsinks (PPFHSs). To this end, the numerical analysis of forward and backward water flow inside the PPFHS with three different attached splitters was performed considering Re of between 50 and 250. The main objective was to determine the locations with intense thermal and frictional entropy generation rates inside the fluid flow geometry. Based on the results, the frictional entropy generation rate is significantly lower than that the thermal term. Also, the pin-fin with arched splitter has the minimum thermal irreversibilities as compared to straight and wavy splitters. Furthermore, the major irreversibilities are associated with the locations near the pin-fin lateral and frontal surfaces as well as the plate fin walls and heatsink upper case and lower base. Moreover, it was shown that for all considered cases and two flow directions, the increasing of the Re results in decreasing and increasing the thermal and frictional entropy generation rates, respectively.
A solar energy system is an excellent solution for electriﬁcation of remote rural areas where the grid extension is difﬁcult and not economical. This article presents a simple optimization method for calculating the optimum conﬁgurations of photovoltaic–battery (PV–bat) systems with high reliability and minimum cost. The proposed method has been applied to design a PV–bat system to supply a typical load requirement in a remote region in Kerman, Iran. To design an optimum stand-alone PV–bat system with high reliability and low costs, the optimization procedure, which is based on the annual electrical demand and solar radiation data, consists of two parts: the model of loss of power supply probability (LPSP) and the model of the levelizedcostofenergy.ForthedifferentdesiredLPSPrequirementsatgivendemand,theoptimal numbersofsolararrayandbatteryhoursofstorageareobtainedattheminimumsystemcost.
In this paper, two-dimensional laminar convective heat transfer of water at a supercritical pressure of 25 MPa in a horizontal rectangular duct has been investigated. The objectives were to understand the thermal and hydrodynamic behavior of fluid flow under different conditions. A set of governing equations containing the continuity, momentum and energy are solved simultaneously using CFD techniques. The finite volume method is employed to obtain the discretized forms of the governing equations. In the numerical solution of these equations, the SIMPLE algorithm is used for pressure-velocity computations. In all the cases studied in this paper, sub-cooled water at a supercritical pressure enters a duct with constant surface temperature which is near to the fluid pseudocritical temperature. For this type of fluid flow with forced convective heat transfer, the pressure, velocity and temperature fields are calculated. Numerical results show that as the fluid temperature becomes closer to the pseudocritical temperature (384.8 °C), the rapid variation of the fluid properties causes an unusual velocity profile for this type of convective flow. In the present work, the crucial influences of two main parameters, the Reynolds number and wall temperature on flow and heat transfer distributions, are thoroughly explored.
The paper presents numerical results for the prediction of two- dimensional laminar heat transfer to water flow at critical pressure. The set of g overning equations containing continuity, momentum and energy are solved simultaneously using CFD technique. The discretized form of each equation is obtained by finite volume method and the SIMPLE algorithm is used for pressure-velocity calculations. In all of the case studies, sub-cooled water at critical pressure (22.1MPa ) enters into a duct with constant surface temperature which is near the fluid critical temperature. Numerical results show that as the fluid temperature approaches the critical temperature, the variations of fluid properties increase rapidly and cause an unusual velocity profile for this type of convective flow. In the present work, the crucial influence of fluid property variation on flow and heat transfer distributions at critical pressure is thoroughly explored
Diesel power technology has been utilized worldwide, especially in remote regions, because of its low initial capital cost. But it has negative effects on the surrounding environment and causes global warming. On the other hand, depleting oil and fuel resources has made it inevitable to seek alternative/renewable energy resources. In Iran, the cost of fuel is highly subsidized. If Iran removes the fuel subsidy, the cost of diesel fuel would increase and the photovoltaic (PV) or hybrid PV/diesel systems would become more attractive. Hybrid photovoltaic/diesel/battery (PV/diesel/bat) systems which use PV energy, combined with diesel generation power and battery bank storage are an excellent solution to decrease diesel generator costs, pollution, and electrification of remote rural areas. In this article, a study using PV/diesel/bat power systems to meet typical load requirements in a remote region in Kerman, Iran is investigated under four different diesel generator fuel price scenarios. A simple optimization method is used to determine the systems with high reliability and low costs. The method used, which is based on annual electrical demand, solar radiation data, and rated power of the diesel generator consists of two parts: The model of loss of power supply probability and the model of the levelized cost of energy. Results show that only under a subsidized diesel fuel price scenario, the diesel-only system has the minimum cost, but by the elimination of diesel fuel price subsidies, the role of the diesel generator decreases in hybrid (PV/diesel/bat) energy systems.
This article presents a feasibility analysis of renewable energy systems for supplying the electrical load requirements of a typical community (50 rural households) in a remote location in Kerman, Iran. The renewable energy systems (photovoltaic/battery [PV/bat], wind/battery [wind/bat] and hybrid photovoltaic/wind/battery [PV/wind/bat]) considered in the analysis were comprised of different combinations of PV modules and wind energy conversion systems (WECS) supplemented with battery storage. The assessment criterion for the analysis was total net present cost of each system configuration. The National Renewable Energy Laboratory\'s Hybrid Optimization Model for Electric Renewable software was utilized as the assessment tool for the present study. The results showed that because of the scatter in the distribution of wind speed (sudden decreases in the wind speeds) in Kerman, the application of WECS results in an increase in the number of wind turbines, the required capacity of battery storages and, consequently, the total net present cost of the wind/bat and hybrid (PV/wind/bat) renewable energy systems. For this reason, the PV/bat system was recommended for supplying the electrical load requirements of the present study.
In the present paper, wind characteristics have been analysed for three agricultural sectors in Kerman (30 15N,56 58E), ′ ′ °° Iran. Wind data collected from three synoptic stations for the period of July 2006 to June 2011 at the height of 40 m has been used to study the monthly and annual wind energy potential. Two statistical methods (Meteorological and Weibull) have been applied to determine the monthly wind energy and density. Wind speed directions and the percentages of wind energy based on wind speeds of more than and equal to 3 m/s have been investigated. A technical assessment has been done to determine the electricity generation from five different wind turbines having capacity of 26 kW, 100 kW, 300 kW, 600 kW and 660 kW. This study is a first stage in a longer project and will be followed by an economic analysis on off-grid and grid connected wind energy power systems
n the present work, a typical combined cooling, heating and power (CCHP) system comprised of boiler, flat solar collectors, absorption chiller and heat storage tank was investigated. The described system was considered to supply the given electricity, cooling and heating demand of a residential building; with heating and cooling needs of 100 and 50 kW, respectively. To find the optimum hybrid configurations with high reliability, low costs, low fuel consumption and emissions, a computer program was provided by authors in FORTRAN language. Different fuel prices were considered in the present work. The results indicated that the optimal operation strategy changes with Boiler and NGG fuel prices while it also changes with increasing the number of solar collectors, heat storage capacity and consequently decreasing total annual emission.
The effect of solar PVs, solar collectors and fuel price on optimization of a typical micro combined cooling, heating and power (CCHP) system based on a natural-gas generator (NGG) was investigated. The CCHP system was considered to supply the given cooling, heating and electricity demand of a 5 story high residential building; having a total of 1000 m2 floor area with the peak electricity of 48 kW, heating and cooling needs of 100 and 50 kW, respectively. If Iran removes the fuel subsidy, the cost of fuel would increase and the PV or hybrid PV/Generator systems would become more attractive. In this paper, a techno-economical procedure was conducted by using two definitions of loss of power supply probability (LPSP) and levelized cost of energy (LCOE). The results indicated that the optimal operation strategy changes with boiler and NGG fuel prices while it also changes with increasing the number of solar collectors.
The application of Linear Fresnel (LF) solar field was technically and economically considered as the thermal source of a Multi Effect Desalination Thermal Vapor Compression (MED/TVC) system with a water production rate of 9000-m3/day. The analysis was made on the five years radiation data of Kish Island, located in the Persian Gulf at south of the Iran. The water production costs were considered for three different configurations of the MED/TVC/LF desalination system to determine the required sizes of LF solar field, system costs and also amount of annual fuel savings. The results of the present study shown that the water production costs of the MED/TVC/LF system is obtained as a value between 1.63 $/m3 and 3.09 $/m3 for the systems without thermal storage and with thermal storage, respectively. The thermal storage system would increase the costs of the water production by about 42% and 65% for 6 h and 12 h of thermal storage, respectively. It was found that the water production cost of the MED/TVC/LF system with 67.77% contribution of solar energy and without the thermal storage system is high (3.32 $/m3) as compared to the conventional fossil fuel powered MED/Desalination plants with a water production cost of 1.26 $/m3.
In the present paper, the integration of the Multi Effect Desalination (MED) system with the Solar Rankine Cycle (SRC) was considered in order to produce electricity and water. Parabolic Trough Collector (PTC) and Linear Fresnel (LF) solar fields were investigated as the thermal source of the SRC and a Natural Gas Boiler (NGB) was considered to supply part of the SRC required thermal energy during the non-availability of the solar thermal energy. A simple optimization approach was used in order to obtain the SRC plants with minimum electricity and water generation costs. A Thermal Storage System (TES) was also considered in the calculations of the present paper. For both PTC/SRC and LF/SRC plants, the required Solar Multiple (SM), electricity generation cost and water production cost were determined for different percentages of the solar share. A comparison between the PTC and LF solar fields was conducted in order to determine the required solar field and land area for producing the specific electricity and fresh water rates. Finally, a sensitivity analysis was performed to determine the importance of each cost parameters on the final electricity and water unit of costs for both PTC and LF base SRC plants.
The Linear Fresnel (LF) solar filed was considered to support part of the required thermal energy of the Solar Rankin Cycle (SRC). Multi Effect Desalination (MED) system was applied in order to produce distillate water by using the SRC thermal energy. Two typical low temperature MED systems with 14 effects and two Output Ratios (GORs) of 9.8 and 12 were considered to be feed by the steam at the outlet of the turbine replacing the condenser of SRC. A simple scheme was proposed to increase the output thermal energy of the saturated steam extracted from the Low Pressure (L.P) steam turbine and to use the obtained dry steam in the first effect of the MED plant. Two thermal storage capacities of 6 and 12 hours were considered in SRC calculations. LF solar field were considered to operate under different mass flow rates and areas of LF aperture. Two LF fields were considered to enhance the possibility of increasing the amount of thermal energy storage. An economic analysis was also used to determine the water and electricity costs of the SRC/MED/LF system. The amount of annual fuel saving and the unit cost of the water and electricity were determined under different scenarios of MED unit GORs and thermal storage capacities
The integration of Multi Eﬀect Desalination (MED) unit with and without Thermal Vapor Compression (TVC) system into the Linear Fresnel Rankine Cycle (LFRC) was investigated for diﬀerent seawater temperatures when it is located at the regions with diﬀerent solar radiation levels. A comparison was made between the fresh water costs of the dual purpose LFRC/MED (or LFRC/MED/TVC) plants and the case when the MED and MED/TVC systems use direct steam of the LF solar ﬁeld to produce fresh water (LF/MED&LF/MED/TVC). The water production costs of the described dual purpose plants were compared with that of the LFRC/Reverse Osmosis (RO) plant (LFRC/RO). An exergo-economic analysis was performed to determine the water unit costs of the plants. The results show that the fresh water costs of the LF/MED and LF/MED/TVC conﬁgurations are higher than that of the dual purpose plants. Also, it was shown that the fresh water cost is more aﬀected by solar radiation level rather than seawater temperature of a region. It was also found that at fuel prices of 0.23$/m3, the water production costs of fuel based dual purpose plants would be equal to that of the plants with solar thermal source
In the present study, the direct steam generated from a linear Fresnel solar field was considered to be used as the working fluid of a Rankine cycle. Four regions located in North and South hemispheres and with different annual direct normal irradiance levels, ranging from 1,950 to 2,750 kWh/m2, were selected to investigate the effect of solar radiation on the performance of a linear Fresnel/solar Rankine cycle (LF/SRC). The condenser of the LF/SRC plant was considered to be replaced by a multi-effect desalination (MED) unit. Different thermal storage capacities were considered for the LF/SRC plant with the electricity generation and water production rates of 85 MW and 80,000 m3/d, respectively. Not only the required solar field area, thermal energy storage (TES) capacity, solar multiple (SM) were investigated but also the water and electricity costs of the plant. A sensitivity analysis was performed on solar field cost, TES system cost and fuel cost in order to determine the sensitivity of the electricity and water unit of costs to each of the mentioned cost parameters. In order to determine the effect of plant size on the water and electricity unit of costs, the calculations were made for the SRC/MED/LF plant with the larger scales.
The scarcity of fresh water resources and the need for additional water supplies is already critical in many arid regions of the world and will be increasingly important in the future. The solar thermal/Multi Effect Desalination (MED) is a candidate to tackle water scarcity. A comprehensive review of the technical and economic aspects of the technology and the state-of-the-art investigations in terms of integration of various MED configurations with different solar thermal sources was provided. Based on the results, the unit cost of the fresh water varies depending on the solar thermal technology and cost, solar radiation level, water production rate, seawater temperature and salinity. Based on the review, the integration of the MED with low temperature (60 °C–95 °C), medium temperature (165 °C–200 °C) and high temperature (370 °C–530 °C) solar collectors leads to water production costs of 2$/–3.6$/, 1.4$/–3.1$/ and 1.8$/−2.2$/, respectively, with a payback period of 4 to 16 years. The directions for the future research include localization of the solar collector industry, the MED brine management, the improvement of the MED and solar collector thermal efficiencies as well as the integration schemes. Useful information is provided to choose the most appropriate combinations of solar/MED technology for small or large applications.
در اﻣﻜﺎن اﻳﻦ ﻣﻘﺎﻟﻪ ﺳﻨﺠﻲ اﻳﺠﺎد ﺳﻴﺴﺘﻢ ﻳﻚ ﺑﺎدی - ﺧﻮرﺷﻴﺪی ﺟﻬﺖ ﺗﺎﻣﻴﻦ اﻧﺮژی اﻟﻜﺘﺮ ﻧ ﻳﻜﻲ ﻣﻮرد ﻴﺎز ﻳﻚ ﺟﺎﻣﻌﻪ روﺳﺘﺎﻳﻲ درﻳﻚ ﻧﺎﺣﻴﻪ دور اﻓﺘﺎده در رﻓﺴﻨﺠﺎن ﻛﺮﻣﺎن ﻣﻮرد ﺑﺮرﺳﻲ ﻗﺮارﮔﺮﻓﺘﻪ اﺳﺖ . اﺑﺘﺪا ﺑﺎر اﻟﻜﺘﺮﻳﻜﻲ ﻣﻮرد ﻧﻴﺎز ﺟﺎﻣﻌﻪ ﻣﺬﻛﻮر ﺑﺮای ﺗﻤﺎم ﻣﺎﻫﻬﺎی ﻳﻚ ﺳﺎل ﻧﻤﻮﻧﻪ ﺗﻌﻴﻴﻦ ﺷﺪه اﺳﺖ . ﻫﻤﭽﻨﻴﻦ ﺑﺎ اﺳﺘﻔﺎده از اﻃﻼﻋﺎت ﭘﻨﺞ ﺳﺎﻟﻪ اﻳﺴﺘﮕﺎه ﻫﻮاﺷﻨﺎﺳﻲ رﻓﺴﻨﺠﺎن ﻣﺤﺘﻤﻞ ﺳﺮﻋﺖ ﺗﺮﻳﻦ ﺑﺎد ﺑﺎ اﺳﺘﻔﺎده ﭼﮕﺎﻟﻲ از ﺗﺎﺑﻊ وﻳﺒﻮل و ﻫﻤﭽﻨﻴﻦ ﻣﻴﺰان اﻧﺮژی ﺗﺎﺑﺸﻲ ﻗﺎﺑﻞ ﺣﺼﻮل ﺑﺎ اﺳﺘﻔﺎده از رواﺑـﻂ اﻧﺮژی ﺧﻮرﺷﻴﺪی اﺳﺖ ﻣﺤﺎﺳﺒﻪ ﺷﺪه , ﺑﺎ ﺳﭙﺲ ﺗﻮﺟﻪ ﺑـﻪ ﻛـﻞ ـﻮرد ﻧﻴــﺎز ﺳــﺎﻟﻴﺎﻧﻪ ، اﻧــﺮژی ﻣـ ـﺮای ﭼﻨــﺪ اﻧﺘﺨــﺎب ﻣﺨﺘﻠــﻒ از ﺑـ ﻣﺴﺎﺣﺖ ﭘﺎﻧﻞ ﺧﻮرﺷﻴﺪی ﺑﺎد ، ﻫﺎی اﻧﺮژی ﻣﻮرد ﻧﻴـﺎز ﺑـﺮای ﻫـﺮ اﻧﺘﺨﺎب ﺗﻌﻴﻴﻦ ﺷﺪ ه اﺳﺖ . در ﻧﻬﺎﻳﺖ ﺑﺎ اﺳـﺘﻔﺎده از ﻣﺸﺨﺼـﺎت ﻓﻨﻲ ﭼﻨﺪ ﺗﻮرﺑﻴﻦ ﻣﺘﻔﺎوت و ﺑﺪﺳﺖ آوردن اﻧﺮژی ﺳﺎﻟﻴﺎﻧﻪ ﺗﻮﺳﻂ ﻫﺮ ﺗﻮرﺑﻴﻦ ﻧﻮع و ﺗﻌﺪاد ﺗﻮرﺑﻴﻦ ﻣﻮرد ﻧﻴﺎز ﺑﺮای ﻫﺮ اﻧﺘﺨﺎب از ﻣﺴﺎﺣﺖ ﭘﺎﻧﻞ اﺳﺖ ﻫﺎ در ﻣﻨﺎﺳﺐ ﺗﺮﻳﻦ ﺣﺎﻟﺖ ﻣﺸﺨﺺ ﺷﺪه .
در این تحقیق، تحلیل ترمودینامیکی و اقتصادی بر روی سیستم ترکیبی مبدل حرارتی جذبی و چرخه رانکین آلی انجام شده است و عملکرد هر دوسیستم با هدف تولید الکتریسیته از منبع دما پایین مورد بررسی قرار گرفته است. کلیه انجام شده است. نتایج نشان میدهد که ضریب عملکرد EES آنالیز براساس قوانین ترمودینامیک میباشد که در نرم افزار به دست میآید. این 44/48% درجه سانتیگراد برابر با 120℃ به70℃ سیستم مبدل حرارت جذبی برای افزایش دما از ضریب عملکرد در دمای ژنراتور بالاتر و کندانسور پایینتر به بیشترین مقدار خود میرسد. با اعمال نرخ حرارت جاذب به کیلووات ساعت در روز به دست میآید. این بازده سیستم در 399 و الکتریسیته 10/58 سیستم رانکین ارگانیک بازده % )LCOE( دمای اواپراتور بالاتر و کندانسور پایینتر به بیشترین مقدار خود میرسد. هزینه سطح بندی شده الکتریسیته دلار برکیلووات ساعت است و این میزان با 0/173 کیلووات حرارت به سیکل رانکین اعمال می شود برابر 382 زمانی افزایش نرخ حرارت، کاهش می یابد و به هزینه خرید الکتریسیته در ایران نزدیک می شود.
اتلافات حرارتی بالا دردامنه دماهای پایین و متوسط، دربخش صنعت و محدودیت های منابع انرژی فسیلی و آثار زیست محیطی آن¬ها موجب استفاده روزافزون از سیستمهای انرژی تجدیدپذیر شده است، ظرفیت حرارت تولیدی سیستمهای انرژی تجدیدپذیر غالبا دردامنه دماپایین است و سیکل رانکین آلی به خوبی میتواند به عنوان یک سیستم کمکی یا بازیاب حرارت در سیستمهای ترکیبی و یا مستقل، در راستای تولید توان الکتریکی به سیستمهای فوق اضافه گردد، در این مطالعه سیکل رانکین ارگانیک از نظر آنالیز انرژی، اگزرژی و اگزرژی-اقتصادی، همچنین بررسی پارامتری در اجزای مختلف سیکل و انتخاب سیال کاری مناسب در راستای تولید توان الکتریکی بهینه سیستم، به صورت پارامتریک مورد ارزیابی قرار گرفته است.
در بسیاری از سیستمهای انتقال آب بویژه آبرسانی به روستاها در مناطق دور افتاده، تامین انرژی مورد نیاز جهت پمپاژ آب مستلزم صرف هزینههای گزاف برای نیرو رسانی و احداث پست برق است. از این رو سیستم پمپ خورشیدی میتواند به عنوان گزینه مناسبی جهت تامین نیاز انرژی در سیستمهای پمپاژ آبرسانی مورد استفاده قرار گیرد. در این نحقیق نخست متوسط تشعشع خورشیدی در هر ساعت در طول سال برای دو منطقه کشاورزی در اطراف شهر کرمان گردآوری شده و توسط نرمافزارهای موجود آنالیز انرژی بر روی دادهها انجام گرفته است. سپس دادهها و مشخصات مربوط به پنج چاه کشاورزی با اعماق متفاوت در منطقه مورد نظر این تحقیق مورد بررسی قرار گرفته است. با توجه به انرژی مورد نیاز سیستم پمپاژ و مقدار تشعشع خورشیدی در هر منطقه، اندازه مناسب سیستم پمپ خورشیدی برای مکش آب از چاه های کشاورزی تعیین گردید. با توجه به اینکه هزینه انتقال خط برق شبکه به مقدار فاصله بستگی داشته و از طرف دیگر هزینه سیستم پمپ خورشیدی وابسته به توان سیستم پمپ خورشیدی میباشد، برای داشتن هزینههای کمتر در یک سیستم پمپ خورشیدی نسبت به پمپهای کنونی، تنها در مواردی که فاصله چاه کشاورزی از خط انتقال برق به اندازه کافی دور باشد، استفاده از سیستم پمپ خورشیدی از نظر اقتصادی مقرون به صرفه است. به عنوان مثال برای توانهای پمپ خورشیدی 5 کیلووات و 25 کیلووات، به ترتیب در حداقل فواصل از شبکه حدود 3200 متر و 6400 متر هزینه مکش آب در پمپ خورشیدی با پمپهای کنونی از نظر اقتصادی قابل رقابت میباشد.
در اﯾﻦ ﭘﮋوﻫﺶ، ﺗﺮاز اﻧﺮژی و اﮔﺰرژی ﺑﺮای ﯾ ـﮏ ﻣﻮﺗـﻮر ﺳـﻪ اﺳـﺘﻮاﻧ ﻪ ﻣﺠﻬﺰ ﺑﻪ ﭘﺮﺧﻮران ﻣـﻮرد ﺑﺮرﺳـ ﯽ ﻗـﺮار ﮔﺮﻓﺘـﻪ اﺳـ ﺖ .ﺗـﺮا ز اﻧـﺮ ژی و اﮔﺰرژی روﺷﯽ اﺳﺖ ﮐـﻪ ﺑـﺮ ﭘﺎ ﯾ ـﻪ ﻗـﻮا ﻧﯿﻦ اول و دوم ﺗﺮﻣﻮدﯾﻨﺎﻣﯿ ـﮏ اﺳﺘﻮار اﺳﺖ و ﺑﺮ اﺳﺎس آن ﺣﺠـﻢ ﮐﻨﺘﺮﻟ ـ ﯽ ﺑـﺮ ر وی ﻣﻮﺗـﻮر اﻧﺘﺨـﺎب ﻣﯽ ﺷﻮد و اﻧﺮژی ﯾﺎ اﮔﺰرژی ورودی و ﺧﺮوﺟﯽ ﺣﺠﻢ ﮐﻨﺘﺮل ﻣ ﺤﺎﺳـ ﺒﻪ و اﻧﺪازه ﮔﯿﺮی ﻣﯽﺷﻮﻧﺪ .ﺑﺎ اﺳﺘﻔﺎده از اﯾﻦ روش ﻫﺎ ﻣ ـﯽ ﺗـﻮان ﺗﻮ زﯾ ـﻊ اﻧﺮژی و اﮔﺰرژی ﻗﺴﻤﺖ ﻫﺎی ﻣﺨﺘﻠﻒ ﻣﻮﺗﻮر را ﻣﺤﺎﺳﺒﻪ ﻧﻤـﻮ د. ﺗﻮزﯾـﻊ اﻧﺮژی در ﻣﻮﺗﻮر اﺣﺘﺮاﻗﯽ ﺑﺎ اﺳـﺘﻔﺎده از داد ه ﻫـﺎی ﺗ ﺠﺮﺑ ـﯽ ﻣﺤﺎﺳـﺒﻪ و اراﺋﻪ ﻣﯽﺷﻮد .آزﻣﺎﯾﺶﻫﺎی ﺗﺠﺮﺑﯽ در ﺗﻤﺎﻣﯽ ﻣﺤـﺪوده ی ﻋﻤﻠﮑـﺮدی o ﻣﻮﺗﻮر و در دﻣﺎی ﺧﻨﮏ ﮐﺎری اﻧﺠﺎم ﺷﺪه اﺳﺖ ﺑﺎ اﻓﺰاﯾﺶ ﺑـﺎر 90 C ﻣﻮﺗﻮر ﺑﺎزده ﺣﺮارﺗﯽ،درﺻﺪ اﻧﺮژی ﻣﻨﺘﻘﻞ ﺷـﺪه ﺗﻮﺳـﻂ دود ﺧﺮوﺟ ـ ﯽ وﻫﻢ ﭼﻨﯿﻦ درﺻﺪ اﻧﺮژی ﺧﻨـﮏ ﮐـﺎر ی در دورﻫـ ﺎی ﭘـ ﺎﯾﯿﻦ اﻓـﺰ اﯾﺶ ﻣﯽ ﯾﺎﺑﺪ .درﺻﺪ اﻧﺮژی ﺧﻨﮏ ﮐﺎری در دورﻫﺎی ﻣﯿﺎﻧﯽ و ﺗﻨﺪ ﺑﺎ اﻓﺰاﯾﺶ ﺑﺎر ﻣﻮﺗﻮر ﮐﺎﻫﺶ ﻣﯽ ﯾﺎﺑﺪ .ﻣﺤﺎﺳﺒﺎت اﮔﺰرژی ﻧﺸـﺎن ﻣـﯽ دﻫـﺪ ﮐـﻪ ﺑـﺎ اﻓﺰاﯾﺶ ﺑﺎر ﺑﻪ ﺟﺰ در دورﻫﺎی ﺗﻨﺪ، درﺻﺪ اﮔﺰرژی ازدﺳﺖ رﻓﺘـﻪ ﺑـ ﻪ ﮐﻞ اﮔﺰرژی ورودی، ﮐﺎﻫﺶ ﻣﯽ ﯾﺎﺑﺪ.
The renewable energy systems (PV/bat, wind/bat and hybrid PV/wind/bat) have been analyzed to support the electrical load requirement of a typical community (50 rural households) in a remote location in Kerman, Iran. . The assessment criterion for the analysis was total net present cost (NPC) of each system configuration. HOMER) software was utilized as the assessment tool. The results shown that because of the scattering distribution of wind speed (sudden decreases in wind speeds) in Kerman, the application of WECS results in increase in the number of wind turbines, the required capacity of battery storages and consequently the total net present cost of the wind/bat and hybrid (PV/wind/bat) renewable energy systems. So, the PV/bat system was recommended to supply the electrical load requirement of the present study.
In Iran, the cost of fuel is highly subsidized. If Iran removes the fuel subsidy, the cost of diesel fuel would increase and the PV or Hybrid PV/diesel systems would become more attractive. In this paper, a study of using PV/diesel/bat power systems, to meet a typical load requirements in a remote region in Kerman, Iran is investigated under four different diesel generator fuel price scenarios. The optimization method which is based on the annual electrical demand, solar radiation data and rated power of diesel generator consists of two parts: the model of Loss of Power Supply Probability (LPSP) and the model of the Levelized Cost of Energy (LCOE). Results show that only under subsidized diesel fuel price scenario, diesel-only system has the minimum costs, but by the elimination of diesel fuel price subsidies, the role of diesel generator decreases in hybrid (PV/diesel/bat) energy systems.
جهت گیری مناسب یک ساختمان میتواند درصد دریافت انرژی خورشیدی مستقیم را در فصول گرم و سرد سال به شکل قابل توجهی به ترتیب کاهش و افزایش دهد. در نتیجه مصرف انرژی سالانه ساختمان را میتوان با تعیین زاویه رو به خورشید مناسب و استفاده از سایبان کاهش داد. در تحقیق حاضر، برای تعیین اندازه و محل بهینه نصب سایبان در پنجرههای یک ساختمان در شهر کرمان از الگوریتم ژنتیک استفاده شده است. تاثیر استفاده از سایبان در مقدار انرژی خورشیدی دریافتی از پنجرههای موجود در چهار طرف ساختمان مورد بررسی قرار گرفت. در نهایت، تاثیر حذف هر کدام از جدارهای نورگذر اطراف ساختمان در افزایش مصرف انرژی سالیانه ساختمان مذکور در شهر کرمان مشخص گردید. نتایج تحقیق نشان داد که ارتفاع بهینه سایبان به اندازه 4/0 متر از بالای پنجره برای فصول سرد و گرم میباشد. و عمق سایبان (فاصله عمود ازدیوار) برای فصول سرد و گرم به ترتیب 2/0 متر و 6/0 متر میباشد. با استفاده از سایبان با اندازه بهینه در فصول سرد، مقدار 17% از کل انرژی حرارتی مورد نیاز ساختمان توسط انرژی خورشیدی تامین شده و برای ماههای گرم، مقدار دریافت انرژی خورشیدی از 43% به 7/4% کاهش مییابد.