{"title":"Performance Analysis of Dual-Evaporator Ejector Refrigeration System in Different Configurations: Experimental Investigation","authors":"Batuhan Üğüdür, M. Di̇rek, Ümit Işkan","doi":"10.58559/ijes.1291259","DOIUrl":"https://doi.org/10.58559/ijes.1291259","url":null,"abstract":"This study aimed to assess the effectiveness of an ejector refrigeration cycle, using a laboratory-scale experimental system operating in different configurations. The configurations included a conventional vapour compression refrigeration cycle (CVCR), as well as a dual evaporator ejector refrigeration system (DEES) operated in two modes: with a single thermal expansion valve (DEESA) and with dual thermal expansion valve (DEESB). Results showed that the use of the ejector increased the mass flow rate of the refrigerant. Moreover, DEESA demonstrated higher cooling capacity and coefficient of performance (COP) than the CVCR system, with the COP being 7 to 21% higher than that of the traditional system. DEESA also showed the highest total cooling capacity compared to other configurations. DEESB, on the other hand, resulted in lower evaporation temperatures and higher superheat values than DEESA. Based on the evaluations, it has been concluded that the ejector operates more efficiently in systems with dual evaporators, leading to positive contributions to system performance.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114474841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Overall review of electricity supply distribution, shortages in Gaza strip, and the current state-of-the-art of renewable power technologies","authors":"Sameh Youni̇s, Güven Tunç","doi":"10.58559/ijes.1317267","DOIUrl":"https://doi.org/10.58559/ijes.1317267","url":null,"abstract":"This study presents a comprehensive assessment of the electricity crisis in the Gaza Strip and its impact on the health and well-being of its population. Using a sequential exploratory mixed-methods approach, both qualitative and quantitative data were collected from 350 households and key players institutions. The study reviewed the current state of renewable power technologies applicable to the region, and developed a performance matrix to identify the most suitable technology as an intervention to provide clean and affordable electricity. The findings indicate that solar energy is the most feasible solution to address the electricity shortage in the Gaza Strip. The study also highlights the negative impact of electricity shortages on essential services, such as health, water, and sanitation services, as well as on the fragile economy. The study recommends investing in solar energy as a reliable and cost-effective solution that is easily accessible to support the needs of the Gaza Strip and Palestine in general. The study provides a valuable resource for national and international NGOs to identify the strengths, weaknesses, opportunities, and threats of the electricity sector in the Gaza Strip.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121882434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Travel Option-Based Environmental Comparison Between Passenger Aircraft and High-Speed Rail","authors":"Ugur Kilic, Ö. Çam","doi":"10.58559/ijes.1300629","DOIUrl":"https://doi.org/10.58559/ijes.1300629","url":null,"abstract":"The short-haul flights have higher emission values than medium or long-haul flights when emissions per distance are considered. In this study, the potential to reduce greenhouse gas emissions by replacing short-haul flights which carried out by a narrow-body commercial aircraft from/to Konya City in Turkey with regional jets or high-speed trains (HSRs) has been investigated. The flight trajectory is selected from Konya Airport to İstanbul Sabiha Gökçen Airport, and that trajectory is a frequently performed domestic flight between Konya and İstanbul. The IMPACT platform is used for the calculation of fuel burn and gas emissions. According to the results, traveling with regional jets or high-speed trains from/to Konya City which is the most 15th polluted city in Europe, provides advantages in terms of environmental impact. Traveling with HSR which is the best traveling option in this study, provides approximately 3.3 times more green travel than the currently used narrow-body passenger aircraft between Konya and İstanbul. In addition, this mode of transportation can become more environmentally friendly by using renewable energy sources to produce its electricity needs. It is expected that this study will serve as a guide for airline and high-speed rail operators and regulators to determine the most environmentally efficient travel options based on fuel burn and emission parameters.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114434532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of the various tritium breeding materials on the tritium breeding ratio in ARC fusion reactor","authors":"Uğur Atalay, Güven Tunç","doi":"10.58559/ijes.1308031","DOIUrl":"https://doi.org/10.58559/ijes.1308031","url":null,"abstract":"This study deals with TBR (Tritium Breeding Ratio) performance of the four different types of molten salt (FLiBe, FLiNaK, FLiNaBe, FLiNaRb) which has four different Li-6 enrichment ratios (0%, 30%, 60%, 90%) Moreover, two different vacuum vessel materials (SiC composite and V4Cr4Ti alloy) have been used in ARC reactor geometry. In models with TBR ≥1.05, it has been desired to examine the sustainability of the tritium production of the reactor by removing the neutron multiplication layer from the design without using the toxic Beryllium element. The neutronic performance studies have been examined in OpenMC, which is an open-source Monte Carlo neutron and photon transport code. The TBR values of the different models obtained and the change of these values according to Li-6 enrichment were examined. Obtaining result showed that the FLiBe molten salt and V4Cr4Ti alloy vacuum vessel wall material could be the best choice for the ARC reactor.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128148042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Investigation of the Thermal Performance and Environmental Impact of a Forced Circulation Solar Water Heating System During the Heating Season","authors":"G. Arslan, Seda Yüksel","doi":"10.58559/ijes.1306783","DOIUrl":"https://doi.org/10.58559/ijes.1306783","url":null,"abstract":"A thermal analysis of a forced circulation solar water heating system (SWHS) was carried out. Three different models were analyzed: SWHS without an auxiliary heater, SWHS with an auxiliary heater, and electric heater only. The study was carried out for the province of Mersin-Turkiye. Flat plate collectors with different structural properties were used in simulations, the best results were obtained with the collector with black chrome absorber coating. This system met 55% of the hot water requirement on the design day without requiring any auxiliary heater. During the season, 18.7% of hot water needs were met in January, 20.42% in February, 37.6% in March, 31.2% in November, and 20.5% in December. SWHS with an auxiliary heater, consumed 1130.3 kWh of electrical energy during the heating season, resulting in 562.7 kg of CO2 emissions. 33 % reduction in greenhouse gas (GHG) emissions is achieved with this system compared to a base system powered by electricity only. The hot water use profile is an essential factor in the design of the SWHS. Since the systems using fossil fuels can meet the needs of the users, energy storage techniques must be adapted to the SWHS to be an alternative.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128801031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Numerical investigation of the effect of operating conditions on the performance parameters of PEM fuel cells","authors":"K. Bilen, Batukan Cem Tarhan, Selahattin Çelik","doi":"10.58559/ijes.1264797","DOIUrl":"https://doi.org/10.58559/ijes.1264797","url":null,"abstract":"The operating parameters of proton exchange membrane fuel cells (PEMFCs) are very effective at generating heat. The study examined and evaluated parameters that can help determine fuel cell performance. The parameters and structures used in systems have been examined. In this context, performance evaluations have been made by performing electrochemical analyses of PEMFCs. Evaluations about how the study parameters affect the performance was made on MATLAB and the results were presented. As a result of the study, it was seen that the operating temperature increased the efficiency until it reached certain limits. On the other hand, although the performance-enhancing effects of the working pressure are observed, high pressure appears as an obstacle. Air stoichiometric rate is another variable that affects fuel cell performance. While high stoichiometric rates improve performance, they can adversely affect the membrane. According to the simulation result, it was found that the working temperature, working pressure and air stockiometry should be optimized together.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"228 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123063520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Comparative Assessment of the Various Split Flow Supercritical CO2 Brayton Cycles for Marine Gas Turbine Waste Heat Recovery","authors":"Serpil ÇELİK TOKER","doi":"10.58559/ijes.1295781","DOIUrl":"https://doi.org/10.58559/ijes.1295781","url":null,"abstract":"Supercritical CO2 Brayton cycle (sCO2 BC) can become easily utilized in marine gas turbine waste heat recovery applications due to their high efficiency, compact size, and low-cost advantages. In this study, the performance of the three different split flow sCO2 BCs, including turbine split flow-1 (TSF-1), turbine split flow-2 (TSF-2), and turbine split-3 (TSF-3), for the recovery of marine gas turbine waste heat is compared. The Engineering Equation Solver (EES) application is used to compare the three different split flow sCO2 BCs' performances. Moreover, to investigate the influence of important thermodynamic parameters on cycle performance, a parametric analysis is carried out. The effect of variable exhaust gas temperature, turbine input pressure, and compressor inlet pressure on net power, the energy efficiency of the system, system's exergy efficiency, and exergy destruction are examined. The results suggest that the energy efficiencies of the TSF-1 sCO2 BC, the TSF-2 sCO2 BC, and the TSF-3 sCO2 BC are calculated by 28.71%, 34.5%, and 29.42%, respectively. It has been determined that the cycle's net power increases with rising exhaust gas temperature and turbine input pressure and decreases with compressor input pressure.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134027229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Proposal And Its Application On The Type-2 Fuzzy Mamdani's Method For The Selection Classification Of The Private Small Hydropower Plant Investments In The Very Early Investment Stages In Turkey","authors":"Burak Omer Saracoglu","doi":"10.58559/ijes.1217872","DOIUrl":"https://doi.org/10.58559/ijes.1217872","url":null,"abstract":"The private small hydroelectric power plant investments (PSHPPIs) differ very much from the other types of the private hydropower plant investments. In most cases, it will be more appropriate for the private electricity generation investors to analyze the alternatives by help of the models proposed only for the PSHPPIs based on the PSHPPIs' own characteristics. This paper pro-poses an online Type-2 Mamdani's fuzzy inference method by help of a Java-based library: Juzzy toolkit, for the selection of the PSHPPIs in the very early investment stages in Turkey. The real-life PSHPPIs' applications have shown that there isn't any clear, detailed, and sharp data and information in the very early investment stages. It is believed that a sophisticated and developed version of this proposed method will help the private investors to take more convenient actions and to make more satisfying decisions in a very short evaluation period in their PSHPPIs processes.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124143296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Site selection of the Antarctic Research stations in aspect of required optimum hybrid renewable system capacity","authors":"Gül Nihal Güğül","doi":"10.58559/ijes.1275463","DOIUrl":"https://doi.org/10.58559/ijes.1275463","url":null,"abstract":"The population of Antarctica consists of scientific research personnel. The number of residents ranges from about 1,100 in the winter to about 4,400 in the summer and up to 1,000 additional personnel in the nearby waters. Even in summer, Antarctica's sub-zero temperature increases the energy consumption of buildings for heating purposes. At the same time, the absence of a grid system necessitates the use of off-grid fossil-based or renewable energy systems. Considering the natural environment and building conditions in the studies, the multiple evaluation of the ground process for research stations is grouped into four main criteria: scientific research, environment, logistical support and topography. In these studies, the capacity of the renewable energy system requirement was not examined. For this reason, in this study, the capacities of the optimum hybrid renewable energy systems in 16 locations selected from different regions of Antarctica were compared. In the study, typical meteorological climate data of 15 locations were obtained. The daily energy demand is obtained by calculating the daily electricity consumption of the electrical devices and heating system that can be used. \u0000Results of this study shows that according to purpose of site, many locations that meets the requirements may exist with extremely different energy demands. In site selection, first the locations should be determined, than energy demands and required systems should be compared.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133742942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Heat transfer enhancement of a slot-confined and submerged impinging jet utilizing lamina-shaped CoFe3O2/water nanofluid","authors":"Recep Ekiciler","doi":"10.58559/ijes.1263940","DOIUrl":"https://doi.org/10.58559/ijes.1263940","url":null,"abstract":"Designing a cooling system is crucial for the thermal management of many different types of energy applications, such as fuel cells, solar panels, electronic cooling, and many more. Higher local heat transfer coefficient is attained by impinging jets, making them a viable cooling option. This study investigates a two-dimensional numerical study into the turbulent convective heat transfer in a confined slot and submerged impinging jet by using water and a nanofluid for Reynolds numbers between 6000 and 24000. The nanofluid of lamina-shaped CoFe3O2/water has been studied, with the volume percentage of nanoparticles ranging from 2.0% to 4.0%. Using a finite volume technique based on the SIMPLE algorithm, the governing momentum, continuity, and energy equations is solved. A presentation and discussion of the influence of the nanoparticle's volume fraction and the Reynolds number on the flow and thermal properties are provided. Increasing the volume fraction of nanoparticles is shown to enhance the Nusselt number and the Darcy friction factor. The optimal condition is also shown to occur at a Reynolds number of 24000 and a nanoparticle volume percentage of 4.0%.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114693785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}