Science and Technology for Energy Transition最新文献

{"title":"Islanding detection in distributed generators using GBDT-JS techniques","authors":"Murali Krishna Goriparthy, Geethalakshmi Balakrishnan","doi":"10.2516/stet/2023006","DOIUrl":"https://doi.org/10.2516/stet/2023006","url":null,"abstract":"Renewable Energy Sources (RES) using PV arrays are considered and extensively employed in today’s world. Islanding is an issue that happens when The RES is connected to the grid and unexpected circuit breakers are connected to the grid trip. It is necessary to notice the islanding condition in two seconds according to IEEE standards. This manuscript proposed an effectual hybrid system for islanding detection of Solar PhotoVoltaic (SPV) based distributed generation system. The proposed technique is a hybrid combination of Gradient Boosting Decision Tree (GBDT) and Jelly Fish Search algorithm (JS) known as GBDT-JS Techniques. The main concept of this paper is to diminish the Non‐Detection Zone (NDZ) and maintain output power quality. These objectives are achieved by the proposed hybrid technique considering the Rate Of Change Of Frequency (ROCOF) at the target DG position is employed by the input assigned for the RF system in intelligent islanding detection. Here, Discrete Wavelet Transform (DWT) is employed for extracting intrinsic features among islanding and grid disturbance along GBDT. Also, the JS algorithm is used in the classification of islanding and grid disturbance. To find the feasibility of the proposed system various conditions such as different loads, switch operation, and network conditions are tested. In the validation of the proposed system MATLAB/Simulink working platform is utilized.","PeriodicalId":272133,"journal":{"name":"Science and Technology for Energy Transition","volume":"135 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115785255","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":"Understanding the performance, emissions, and combustion behaviors of a DI diesel engine using alcohol/hemp seed oil biodiesel/diesel fuel ternary blends: Influence of long-chain alcohol type and concentration","authors":"Zeki Yilbaşi, M. Yeşilyurt, Mevlüt Arslan, H. Yaman","doi":"10.2516/stet/2023003","DOIUrl":"https://doi.org/10.2516/stet/2023003","url":null,"abstract":"In this study, it was aimed to examine the influences of biodiesel–diesel-higher alcohol (1-pentanol, 1-hexanol, and 1-heptanol) blends on the performance, emission and combustion behaviors of a single-cylinder diesel engine. The tests were performed at a fixed speed of 1500 rpm and variable loads (25%, 50%, 75%, and 100%). For the tests, 80% diesel and 20% hemp seed oil biodiesel were blended and called as B20. Biodiesel fuel was produced by transesterification from hemp seed oil in the presence of methanol and potassium hydroxide for the preparation of B20 binary test fuel and other ternary fuels. Furthermore, nine ternary blend fuels [20% HSOB + 70%, 60% and 50% diesel, respectively + 10%, 20% and 30% higher alcohol (pentanol, hexanol and heptanol) respectively] were prepared. The calculations made with the experimental data revealed that the minimum brake specific energy consumption values were 12,48 MJ/kW h, 13,06 MJ/kW h, 13,27 MJ/kW h, 13,35 MJ/kW h, 13,47 MJ/kW h, and 13,59 MJ/kW h, respectively, for diesel fuel at full load, for fuels B20, B20Hx10, B20Hp10, B20Hx20 and B20Pe10, the maximum brake thermal efficiency values were obtained as 28.85%, 27.56%, 27.14%, 26.97%, 26.73% and 26.49%, respectively, for the same fuels at the same load. The increment in higher alcohol concentration in the blend delayed start of combustion and therefore the ignition delay period was prolonged. In the fuel line pressure data, changes were observed depending on the amount, viscosity and density of the fuel. Furthermore, B20Hx10 and B20Hp10 fuels gave the maximum in-cylinder pressure, heat release rate, average gas temperature and pressure rise rate values after diesel and biodiesel. The addition of biodiesel and higher alcohol to diesel fuel resulted in a decrease in NOX, CO and unburned HC and smoke emissions and an increase in CO2. NOX, CO and unburned HC values of higher alcohol blended fuels at full load showed lower results, between 3.04–22.24%, 22.85–56.35% and 5.44–22.83%, respectively, compared to diesel fuel. It can be concluded that the use of hemp seed oil biodiesel and higher alcohol in the diesel engine will make a significant contribution to the reduction of NOX emissions.","PeriodicalId":272133,"journal":{"name":"Science and Technology for Energy Transition","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123709784","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":"An application of a multiindex, time-fractional differential equation to evaluate heterogeneous, fractured rocks","authors":"R. Raghavan, Chih-Cheng Chen","doi":"10.2516/stet/2022024","DOIUrl":"https://doi.org/10.2516/stet/2022024","url":null,"abstract":"A multiindex, distributed fractional differential equation is derived and solved in terms of the Laplace transformation. Potential applications of the proposed model include the study of fluid flow in heterogeneous rocks, the examination of bimodal fluid exchange between mobile-immobile regions in groundwater systems, the incorporation of the existence of liesegang bands in fractured rocks, and addressing the influences of faulted and other skin regions at interfaces, among others. Asymptotic solutions that reveal the structure of the resulting solutions are presented; in addition, they provide for ensuring the accuracy of the numerical computations. Fractional flux laws based on Continuous Time Random Walks (CTRW) serve as a linchpin to account for complex geological considerations that arise in the flow of fluids in heterogeneous rocks. Results are intended to be applied at the Theis scale when combined with geological/geophysical models and production statistics to all aspects of subsurface flow: production of geothermal and hydrocarbon fluids, injection of fluids into aquifers, geologic sequestration and hazardous waste disposal. Results may be extended to study the role of complex wellbores such as horizontal and fractured wells and more complex geological considerations such as faulted systems.","PeriodicalId":272133,"journal":{"name":"Science and Technology for Energy Transition","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128479212","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":"Inverse estimation of wall temperature measurement under dispersion medium shielding based on CMA-ES algorithm","authors":"Lin-Feng Qian, Yuyin Ji, Zezhi Zhu, Di Wu, Guangqiang Xu, Yong Huang","doi":"10.2516/stet/2022013","DOIUrl":"https://doi.org/10.2516/stet/2022013","url":null,"abstract":"Special equipment is often accompanied by the phenomenon of high temperature and high pressure in operation, and it needs to be measured. With the deepening of research engineering application, some new problems appear, such as how to accurately measure and control the combustion temperature field in the hydrocarbon energy system, carry out combustion diagnosis, control the combustion temperature, minimize the generation of pollutants, put forward higher requirements for measurement technology. High temperature has a core impact on equipment safety, which is a key index that must be considered in design and material selection. Near the surface of these high-temperature objects, there are usually high-temperature translucent media and particles produced by combustion, which have a great impact on radiation temperature measurement. At the same time, with the change of temperature and concentration, these translucent media often have gradient refractive index change, which has a certain impact on radiation temperature measurement. These shielding objects interfere with radiation and affect the accuracy of measurement. This topic mainly focuses on the theoretical and experimental research of this kind of problem. The inversion algorithm of wall temperature reconstruction under the shielding condition of dispersed medium is proposed. Under the condition of introducing different measurement errors, the algorithm is verified, and the corresponding numerical simulation is carried out to verify the feasibility of the algorithm model.","PeriodicalId":272133,"journal":{"name":"Science and Technology for Energy Transition","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121608273","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}