International Journal of Energy Studies最新文献

{"title":"MODEL OF THE COMBI BOILER APPLIANCE IN TRNSYS FOR DOMESTIC HOT WATER CIRCUIT: EXPERIMENTAL AND NUMERICAL VALIDATIONS OF ECO MODE SIMULATIONS","authors":"Okan Gök, A. Atmaca, H. M. Altay, Aytunç Erek","doi":"10.58559/ijes.1196504","DOIUrl":"https://doi.org/10.58559/ijes.1196504","url":null,"abstract":"Combi boiler type heating appliances are used nearly in every residential building for both space and domestic hot water (DHW) heating functions. There are challenging targets regarding both of these functions. Since there is a huge laboratory testing procedure behind each appliance design and the structural or operational changes on the regular designs, simulation models could be established for the initial evaluations of the appliance testing. Therefore, due to the estimations from the preliminary results of the simulations, the number of the laboratory tests could be decreased with cost, time, and energy savings. In this study, the main objective is modelling DHW heating circuit of a combi boiler appliance with the help of Transient System Simulation Tool (TRNSYS 18) to calculate DHW outlet temperature under various operating conditions. The TRNSYS model is validated experimentally and compared with the previous works of the authors. A good agreement is achieved in both transient and steady-state regions and the TRNSYS model is found superior when compared to the previously established one-dimensional model of the authors. DHW circuit model is validated only for economic (eco) working mode simulations in this study. Mean absolute error (MAE), mean square error (MSE), and root mean square error (RMSE) values are compared for the outcomes of the previously constructed one-dimensional model and currently established TRNSYS model with reference to the experimental data. TRNSYS model decreases all of these errors calculated according to the overall temperature profiles including the transient region for the central heating water at the heat cell inlet, central heating water at the heat cell outlet, and the inlet and outlet temperature difference of DHW at the experimentally investigated DHW flow rates of 5 l/min, 7 l/min, and 8.7 l/min.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125485007","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":"Fuel estimation of commercial aircraft for the climb-out phase using gaussian process regression model","authors":"V. E. Atasoy","doi":"10.58559/ijes.1207971","DOIUrl":"https://doi.org/10.58559/ijes.1207971","url":null,"abstract":"In this study, Gaussian Process Regression (GPR) is utilised to accurately estimate fuel consumption. For this purpose, ten randomly determined flights performed by Boeing B737-800 twin-engine medium-haul narrow-bodied commercial aircraft are selected. In this context, actual flight data obtained from the Flight Data Recorder (FDR) is used to estimate fuel consumption during the climb-out phase. Different statistical tests, namely Root Mean Square Error (RMSE), coefficient of determination (R2), and Mean Absolute Error (MAE), are applied to evaluate the performance of the GPR in this paper. RMSE, R2, and MAE values for GPR is calculated to be 209.41, 0.99, and 111.38, respectively. As can be seen from the results of all statistical tests, the GPR model indicates successful performance.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131068478","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":"Evaluation of Energy Efficient Building Envelope Alternatives for Sustainable Cities","authors":"Alper Balo, Serhat Karyeyen","doi":"10.58559/ijes.1219774","DOIUrl":"https://doi.org/10.58559/ijes.1219774","url":null,"abstract":"In this study; In the case of replacing the building external wall components of an existing construction designed with internal insulation in the climatic conditions of Ankara, the change in energy performance has been investigated. The analysis was done with the help of BIM-based Revit Program and “Green buildings studio” where energy simulations were created. In the study, 54 different wall combinations were created by modeling combinations of different construction (porous, gas concrete and pumice bricks), insulation (glass wool, rock wool, sheep wool, PUR, XPS and EPS) and roof (tile, asphalt shingle and green roof) materials. When the outputs obtained from the analyzes were evaluated, the lowest energy consumption values were observed in the combination of pumice brick wall, green roof and polyurethane insulation materials. In this scenario, the annual fuel consumption per square meter is determined as 30000.6 MJ/m2. On the other hand, the highest energy consumption values were observed in the combination of porous brick wall, tile roof and sheep wool insulation materials. In this scenario, the annual fuel consumption per square meter is determined as 30026.6 MJ/m2. Although there are not high numerical differences between the findings, it has been observed that the results give consistent results with the thermal conductivity coefficients of the materials used in the combinations.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134220440","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":"Metaheuristic optimization of double flash based combined heat and power system by using process simulator as black-box function generator","authors":"V. Akkaya","doi":"10.58559/ijes.1188061","DOIUrl":"https://doi.org/10.58559/ijes.1188061","url":null,"abstract":"The energy crisis in Europe has increased the importance of energy alternatives to hydrocarbons. For example, geothermal resources have long been proven to be very efficient heat sources for conventional power cycles. To get the maximum benefit from such a system, it is essential to carefully optimize the system parameters. On the other hand, the topology and nonlinear nature of the system prevent it from being expressed as an analytical function and being differentiable. Thus, derivative-based deterministic optimization methods are difficult to apply. In this study, it is proposed to model a geothermal-based dual-flash combined heat and power system in a process simulator and use it as a black-box function generator to calculate the values of the objective and constraint functions. The system parameters that will provide the maximum combined heat and power efficiency are determined by the Genetic Algorithm. Accordingly, with the optimum system design, the total net turbine power is 132.78 kW. The amount of heat utilized is 15020.10 kW.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126858178","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":"Reduced Oxygen Concentration Effects on Scramjet Engine Combustion Characteristics","authors":"Afşin Kılıçarslan Özbek, Serhat Karyeyen","doi":"10.58559/ijes.1218754","DOIUrl":"https://doi.org/10.58559/ijes.1218754","url":null,"abstract":"Air vehicles have began to develop with advancing technology. In order to increase the thrust and reduce pollutant levels at high speeds, researchers focus on different combustion techniques. For this purpose, within the scope of this study, A Scramjet engine combustor has been studied. The effect of reduced oxygen concentration in the air on Scramjet engine combustion was investigated. A hydrogen fueled Scramjet engine is used. In order to seek oxygen concentration effects on combustion characteristics of the Scramjet engine combustor, oxygen concentration in the oxidizer (by mass) was reduced, and the concentration conditions were performed at 23.2%, 21%, 20%, 19%, 18%, 17%, 16%, and 15%. Fort he modelings Reynolds Average Navier-Stokes (RANS) standard turbulence model is preferred for turbulent modeling. A combination of Eddy Dissipation and Finite Rate combustion model was selected to model combustion. The data obtained through the modelings were compared with the experimental data, and the results are in good agreement with the measurements. The results predicted are evaluated, and it was concluded that the velocity increased as the oxygen concentration was increased. It was also predicted that the temperature difference caused by the oxygen concentration decreased with moving away the flame position from the combustor.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127749672","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 helium dilution on the dynamic stability of lean premixed methane flame in a model gas turbine combustor","authors":"Buğrahan Alabaş, Adem Altinay","doi":"10.58559/ijes.1169274","DOIUrl":"https://doi.org/10.58559/ijes.1169274","url":null,"abstract":"Today, where clean, renewable and high efficiency energy production gains importance, methane gas draws attention due to its low carbon content. In this study, flame instability and temperature of methane gas were tested in a premixed model gas turbine combustor at different helium dilution conditions. The burner power was kept constant as 3 kW and the equivalence ratio as 0.7. In addition, a swirl generator with a swirl number of 1 is placed at the burner outlet. The dynamic pressure values of the flame were recorded under external acoustic enforcements at different frequencies applied to the flame and thermo-acoustic combustion instability was interpreted. Methane flame diluted with Helium at 10, 20, 30, 40 and 45 volumetric ratios showed the following results. If helium dilutions of up to 20% did not significantly affect flame instability, instability increased at 30% He. After this critical value, when 45% He dilution was tested, the lowest instability value was determined. In addition, the burner exit temperature of the flame decreased at all helium dilution ratios.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121631725","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":"Piezoelectric energy harvesting from vortex-induced vibrations on a GFRP beam with embedded piezoelectric patch","authors":"H. Ucar","doi":"10.58559/ijes.1189071","DOIUrl":"https://doi.org/10.58559/ijes.1189071","url":null,"abstract":"In the present era, the demand for energy continues to increase and nevertheless, energy resources are gradually decreasing. Therefore, extracting energy from the operating ambient is of great importance especially for industrial applications. Among the numerous available ambient energy sources, wind energy is one of the most promising and prevalent energy sources existing in the environment. In this study, a piezoelectric energy harvester (PEH) consisting of an electromechanical coupling of GFRP cantilever beam with an embedded piezoelectric patch is developed for wind energy harvesting. The cantilever beam under the wind flow vibrates due to the pressure field that occurs on the leeward side of the beam. The generation of the pressure field is based on the vortex shedding phenomenon. Theoretical model of the regarding electromechanical coupling subjected to vortex induced vibration is presented and the effect of the pressure field having various vortex shedding frequencies on harvested power is investigated by means of numerical simulations validated with an experimental study. In order to determine the effect of the direction in which the wind excites the PEH, two wind flow conditions are considered; cross wind and head wind. According to the results, it was found that the PEH generates considerably more voltage outputs under cross wind loading than that obtained from the head wind excitation. In cross wind case, maximum open circuit voltage of 82.4 V is obtained at the wind speed of 6 m/s with the vortex shedding frequency of 18 Hz, which is very close to the second resonance frequency of the PEH. With a calculated load resistance of 100 kΩ, the resulting maximum direct voltage and electric power is 58.7 V and 11.5 mW, respectively. As far as the energy efficiency of PEH is concerned, it is determined that the efficiency is about 0.75 for the frequency of 18 Hz, which is quite acceptable for energy harvesting. It is concluded that a composite PEH with an embedded piezoelectric patch can be used as an effective energy harvester for the vortex induced vibration when the vortex shedding frequency is close to its resonance frequency.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132278477","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":"The challenges and serviceability of solar power: suggestion on solving the Nigeria energy crisis","authors":"A. Tansu, Ayomide Titus Ogungbemi, Fatma TANSU HOCANIN","doi":"10.58559/ijes.1177950","DOIUrl":"https://doi.org/10.58559/ijes.1177950","url":null,"abstract":"For long decades, Nigeria has the highest population in Africa and has been struggling by slow economic growth, poor GDP per capita, high unemployment, and a host of other problems.These problems affect the country's energy sector which in turn leads to a negative crisis feedback loop. The Nigeria energy sector has been labeled by both its citizens and foreigners as a total failure in terms of economic perspective. Despite the continuous government investment over the years, there has been a slight growth in the sector with an ever-rising demand due to its population explosion, leading to a total breakdown across Nigeria economic and industrial development. This study aims to examine how the country can maximize its full energy potential by turning towards the vast quantities of solar resources at its disposal. A review of the nation’s solar energy policies was done with the aim to identify the barriers hindering the country’s solar development, the serviceability of solar energy to the country. Researchers attempt to demonstrate Nigeria's energy gains through the incorporation of solar energy into the country's energy resources.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"291 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115230932","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":"Decontamination applications in primary circuit equipment of nuclear power plants","authors":"Yasin Çetin, A. Acır","doi":"10.58559/ijes.1178889","DOIUrl":"https://doi.org/10.58559/ijes.1178889","url":null,"abstract":"Due to the reactions taking place in the reactor, radioactive contamination occurs on and/or near the surfaces of the equipment used in nuclear power plants. Contamination is a radioactive pollution in the solid phase, which may exist in solution or be carried as a gas/vapor. It can be caused by a very small amount of radioactive material, and since every known element has at least one radioactive isotope, there are more than a hundred elements that can cause contamination. Removing of this contamination by physical and chemical methods is defined as decontamination. The main purpose of decontamination is reducing the activity level of contaminated equipment which may occur during operation or after decommissioning of nuclear power plants. By decontamination process, the radioactive contamination formed on the surfaces or in the depths close to the surface of the equipment is removed by chemical and physical methods. Within the scope of this study, decontamination applications in the literature were explained; regulatory perspective and legislative infrastructure issues for Turkey were discussed. Within the scope of this study, the decontamination applications in the literature were explained, the regulations of the Regulatory Bodies in other countries for decontamination were examined, and in this direction, the regulatory perspective for Turkey and the suggestions for the legislative infrastructure were discussed.","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123931228","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":"Production and determination of properties of ethanol from mango and orange peels","authors":"Anas Bala, Richard Balthi Msheli̇a, Jamilu Ya’u Muhammad, M. Adam","doi":"10.58559/ijes.1147674","DOIUrl":"https://doi.org/10.58559/ijes.1147674","url":null,"abstract":"The use of fossil fuels in IC engines in vehicles and industries has been identified as the leading cause of pollution, especially in urban areas where the traffic is usually heavy and industries are situated. In addition to air pollution which has its attendant health risks, the emission of greenhouse gases from the combustion of fossil fuels has been identified as one of the leading causes of climate change. The aforementioned reasons coupled with the fact that fossil fuels are exhaustible resources have necessitated the search for alternative eco-friendlier and sustainable fuels. The utilization of agricultural waste such as (mango and orange) peels to produce bioethanol proves to be a better alternative than the use of food crops. In this research, enzymatic scarification of yeast (Saccharomyces cerevisiae) was used to produce bioethanol from samples of mango and orange peels and their properties were compared with those of standard pure (98%) anhydrous ethanol. ASTM standards were used as comparative measures of the fuel properties that derived from bioethanol. It was found that the bioethanol concentration for the two samples were 19.98% for sample A and 19.17% for sample B and the results also show a good agreement as analysed by (ANOVA).","PeriodicalId":159867,"journal":{"name":"International Journal of Energy Studies","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121374350","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}