Energetika最新文献_第4页

Parameters affecting biomass drying during combustion in moving grate furnaces 影响移动炉排燃烧过程中生物质干燥的参数

Energetika Pub Date : 2019-05-15 DOI: 10.6001/ENERGETIKA.V65I1.3976

L. Vorotinskienė

{"title":"Parameters affecting biomass drying during combustion in moving grate furnaces","authors":"L. Vorotinskienė","doi":"10.6001/ENERGETIKA.V65I1.3976","DOIUrl":"https://doi.org/10.6001/ENERGETIKA.V65I1.3976","url":null,"abstract":"The most efficient way so far to extract energy from renewable sources is combustion of solid fuel. Solid fuel furnaces of moderate capacity (5–10 MW) equipped with reciprocating grates are most popular. Grate combustion is a well-developed technology; however, to burn biofuel in this type of furnaces in the optimal and safe way, the fuel must be of high quality and have at least constant moisture content. However, increasing demand for biofuel results in increasing prices. To remain in the market and to stay competitive, heat producers choose to utilise moist biofuel of lower quality, whose moisture content can vary and reach up to 60% wt. The burning on the grate of such biofuel is complicated as the drying process occupies most of the space in the furnace. The purpose of this work was to analyse processes taking place in a furnace, such as: primary air supply, influence of flue gas recirculation and radiation from hot surfaces of the furnace to biofuel drying. Analysis of the data obtained would provide technical decisions facilitating optimal fuel combustion in a furnace without additional investments. Analysis of biofuel drying was performed in an experimental setup with a fixed fuel bed. The experiments were performed with wood chips and four different drying fluid temperatures. The results of experimental studies have shown that the drying rate of biofuels upper layers is strongly influenced by radiation from hot surfaces and the moisture content of the sample decreases by 18% wt.","PeriodicalId":35639,"journal":{"name":"Energetika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44001367","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}

引用次数: 3

Heating modes and design optimization of cogeneration steam turbines of powerful units of combined heat and power plant 热电联产发电厂大型机组热电联产汽轮机供热方式及设计优化

Energetika Pub Date : 2019-05-15 DOI: 10.6001/ENERGETIKA.V65I1.3974

A. Rusanov, A. Shubenko, O. Senetskyi, O. Babenko, R. Rusanov

{"title":"Heating modes and design optimization of cogeneration steam turbines of powerful units of combined heat and power plant","authors":"A. Rusanov, A. Shubenko, O. Senetskyi, O. Babenko, R. Rusanov","doi":"10.6001/ENERGETIKA.V65I1.3974","DOIUrl":"https://doi.org/10.6001/ENERGETIKA.V65I1.3974","url":null,"abstract":"An important scientific and technical problem of increasing the efficiency of CHP steam turbine units through the optimization of their operation modes and the creation of new highly efficient flow parts of cogenerating turbines is solved. Solutions to the problem of rational distribution of heat loads between the network heaters of cogeneration turbines during the heating period are presented. The calculations were performed using the software package SCAT which was developed in IPMach NAS of Ukraine. The carrying out of calculations of three-dimensional turbulent flows in flow parts of turbines using modern software systems is an effective direction of increased efficiency of power equipment. For the numerical research of three-dimensional currents, steam in the flow part of the steam turbine software package IPMFlow which is developed in IPMach NAS of Ukraine is used. With the use of software package IPMFlow, the researches of three-dimensional currents steam in the flow part of the medium pressure cylinder of the steam turbine of series T-100-130 are carried, which showed the feasibility of optimizing the geometry of the flow part in order to improve gas-dynamic characteristics of blades apparatuses.","PeriodicalId":35639,"journal":{"name":"Energetika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47037799","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}

引用次数: 8

Rogowsky coil applications for power measurement under non-sinusoidal field conditions Rogowsky线圈在非正弦场条件下功率测量中的应用

Energetika Pub Date : 2019-05-15 DOI: 10.6001/ENERGETIKA.V65I1.3972

I. Diahovchenko, Roman Mykhailyshyn, D. Danylchenko, S. Shevchenko

引用次数: 14

The investigation of factors determining wind power prediction accuracy: case study of western Lithuania 影响风电预测精度的因素研究——以立陶宛西部为例

Energetika Pub Date : 2019-05-15 DOI: 10.6001/ENERGETIKA.V65I1.3978

Giedrius Gecevičius, Mantas Marčiukaitis, M. Tamašauskienė

{"title":"The investigation of factors determining wind power prediction accuracy: case study of western Lithuania","authors":"Giedrius Gecevičius, Mantas Marčiukaitis, M. Tamašauskienė","doi":"10.6001/ENERGETIKA.V65I1.3978","DOIUrl":"https://doi.org/10.6001/ENERGETIKA.V65I1.3978","url":null,"abstract":"In order to mitigate climate change, more attention every year is being given to wind energy. However, despite minimal impact of wind turbines on the environment, there is a negative side as well. Wind speed variations are a stochastic process, and it is difficult to predict wind power accurately. Therefore, unpredictable power can disbalance the power grid; besides, huge power reserves are necessary. Wind energy can be forecasted based on statistical, physical or hybrid methods and models. However, all methods and models generate power prediction errors during different time horizons. The paper presents an analysis of wind power prediction errors determining factors based on statistical, physical and hybrid approaches. Investigation revealed that combination of statistical methods – nonlinear regression, model output statistics, the most suitable power curve and wind speed correction methods – reduced wind power prediction errors up to 1.5%. A detailed evaluation of relief variations and surface roughness increased wind power accuracy by 2%. Considering the local conditions of the western part of Lithuania, the best suitable tool for a short-term wind power prediction is a hybrid model including a detailed description of topographical conditions and the most precise statistical methods.","PeriodicalId":35639,"journal":{"name":"Energetika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43122319","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}

引用次数: 0

The use of mathematical models for the regulation of hydrogenerator voltage control 数学模型在水轮发电机电压控制调节中的应用

Energetika Pub Date : 2019-03-17 DOI: 10.6001/ENERGETIKA.V64I4.3891

F. Shkrabets, V. Radchenko

引用次数: 0

Improvement methods for solving the distribution network reconfiguration problem 解决配电网重构问题的改进方法

Energetika Pub Date : 2019-03-17 DOI: 10.6001/ENERGETIKA.V64I4.3892

Ha Duc Nguyen, I. Valeev

引用次数: 7

Investigation of the energy efficiency of waste utilization technology, with considering the use of low-temperature separation of the resulting gas mixtures 考虑对产生的气体混合物进行低温分离的废物利用技术的能效调查

Energetika Pub Date : 2019-03-17 DOI: 10.6001/ENERGETIKA.V64I4.3893

S. Vambol, V. Vambol, V. Sobyna, V. Koloskov, L. Poberezhna

{"title":"Investigation of the energy efficiency of waste utilization technology, with considering the use of low-temperature separation of the resulting gas mixtures","authors":"S. Vambol, V. Vambol, V. Sobyna, V. Koloskov, L. Poberezhna","doi":"10.6001/ENERGETIKA.V64I4.3893","DOIUrl":"https://doi.org/10.6001/ENERGETIKA.V64I4.3893","url":null,"abstract":"Currently, there are existing technologies for high-temperature waste disposal, which use the resulting gas as fuel for recycling newly formed waste. However, the composition of waste is not constant, and contents of their components are different, thus, the need for fuel gas for burning is not stable. Therefore, such gas is constantly lost. Thus, the purpose of the article is to present the study results of the energy efficiency of high-temperature waste disposal technology, which includes low-temperature separation of the resulting gas mixtures, which allows accumulating fuel products. By means of numerical simulation an analysis of the functioning of energy-technological facility of separation of multicomponent hydrocarbon mixtures with the subsequent optimization of its parameters in order to improve its efficiency and decrease energy costs for waste gasification was performed. For this purpose, the classical approach and generally accepted thermodynamics relations were used, including the Peng-Robinson equation of state for the description of coefficients of heat-physical characteristics of working bodies. The complexity of calculation of multicomponent systems (with three and more components) does not allow application of the state diagrams. Thus, for the simulation of heat-physical characteristics the REFPROP program was employed. The energy efficiency of the proposed technology of energy resources production at waste utilization was shown. The amount of products obtained by the facility is equal to 5.242 kg/hour of the fuel product No. 1 with methane content of 99.98% and 54.76 kg/hour of the fuel product No. 2 with low quantity of methane. This confirms the economic efficiency of such technology of disposal.","PeriodicalId":35639,"journal":{"name":"Energetika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42447635","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}

引用次数: 42

Lietuvos upių ekologinio nuotėkio vertinimas

Energetika Pub Date : 2019-03-17 DOI: 10.6001/ENERGETIKA.V64I4.3894

Brunonas Gailiušis, Gintaras Adžgauskas, Aldona Tomkevičienė, Diana Meilutytė-Lukauskienė

{"title":"Lietuvos upių ekologinio nuotėkio vertinimas","authors":"Brunonas Gailiušis, Gintaras Adžgauskas, Aldona Tomkevičienė, Diana Meilutytė-Lukauskienė","doi":"10.6001/ENERGETIKA.V64I4.3894","DOIUrl":"https://doi.org/10.6001/ENERGETIKA.V64I4.3894","url":null,"abstract":"Tvenkiniai daro įtaką reguliuotų upių vandens organizmams, upės nuotėkiui, tvenkinio krantams ir upės vagai, požeminiams vandenims bei kraštovaizdžiui. Šiuo metu galiojantys teisės aktai reglamentuoja gamtosaugos debitą kaip 30 parų minimalaus debito dalį. Šis debitas tenkina tik minimalius vandens ekosistemos poreikius ir nepriklauso nuo metų vandeningumo. Tokia gamtosaugos debito apskaičiavimo praktika hidroelektrinėms palieka hidropikingo galimybę.\u0000 Straipsnyje aptariami kai kurie Lietuvos mažų ir vidutinių upių tvenkinių eksploatacijos aspektai. Siūloma vietoje gamtosaugos debito reguliuotai upei žemiau tvenkinio nustatyti ekologinį nuotėkį. Svarbiausia sąlyga apskaičiuojant ekologinį nuotėkį – tvenkinio lygių ir reguliuotos upės debitų kaitos panašumas su natūralių ežerų ir upių režimu. Nustatyta, kad neištirtų upių prietaka į tvenkinį ir ekologinis nuotėkis gali būti apskaičiuoti iš atraminių vandens matavimo stočių duomenų kiekviename 15 Lietuvos upių baseinų. Siekiant reguliuotų upių geros ekologinės būklės, siūloma tobulinti HE turbinas, leidžiančias naudoti upės nuotėkį HE plačiame debitų kaitos intervale, išvengiant pikinio darbo režimo (hidropikingo).","PeriodicalId":35639,"journal":{"name":"Energetika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41628130","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}

引用次数: 0

Definition of indicators for decision-making to contribute to sustainable development through Cleaner Production and Resource Efficiency by using the AHP method 利用AHP方法确定通过清洁生产和资源效率促进可持续发展的决策指标

Energetika Pub Date : 2018-10-29 DOI: 10.6001/ENERGETIKA.V64I3.3808

F. Osmani, A. Kochov

{"title":"Definition of indicators for decision-making to contribute to sustainable development through Cleaner Production and Resource Efficiency by using the AHP method","authors":"F. Osmani, A. Kochov","doi":"10.6001/ENERGETIKA.V64I3.3808","DOIUrl":"https://doi.org/10.6001/ENERGETIKA.V64I3.3808","url":null,"abstract":"Rapid growth within the industry sector creates an array of novel issues that have to be dealt with. Major problems as a consequence of continuous and quick development of industry are as follows: the need for high energy consumption (be it electric or thermal), the increase in the level of environmental pollution, and the treatment of waste. Countries in transition, characterized by “an industry in the making”, need to seriously consider the above-mentioned issues. The industry should be subject to professional analysis (the application of resource efficiency and cleaner production) in order to achieve an adequate use of resources. Furthermore, as a result of increased resource efficiency, the industry sector and enterprises will benefit. Greater effectiveness will undoubtedly encourage the use of cleaner production and the launch of the Resource Efficiency and Cleaner Production (RECP) application in the developing countries (such as the Kosovo case). This research focused on the promotion of sustainable development based on RECP in Kosovo. Based on RECP, analysis has been conducted with the help of the method of Multi-Criteria Decision-Making – Analytic Hierarchy Process for all levels of decision-making. The process is based on four main pillars of sustainable development: environmental, technical, economic, and social. Through RECP, there have been identified specific areas in need of improvement in order to achieve the level within the allowed norms of rational energy consumption, minimize environmental pollution and waste, and maximize the profits of the industry sector (enterprises), which, in turn, can lead to the creation of more jobs.","PeriodicalId":35639,"journal":{"name":"Energetika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42566441","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}

引用次数: 5

Numerical evaluation of systematic errors of a non-invasive intracranial pressure measurement 无创颅内压测量系统误差的数值评估

Energetika Pub Date : 2018-10-29 DOI: 10.6001/energetika.v64i3.3805

Edgaras Misiulis, Gediminas Skarbalius, A. Džiugys

{"title":"Numerical evaluation of systematic errors of a non-invasive intracranial pressure measurement","authors":"Edgaras Misiulis, Gediminas Skarbalius, A. Džiugys","doi":"10.6001/energetika.v64i3.3805","DOIUrl":"https://doi.org/10.6001/energetika.v64i3.3805","url":null,"abstract":"Intracranial pressure (ICP) monitoring procedure can be applied to aid in secondary brain damage prevention. A high invasiveness of commonly used ICP measuring methods poses a risk of complications, and therefore new non-invasive methods are currently being developed. A promising non-invasive ICP measurement method is based on the existence of pressure balance state, which is driven by the unique morphological property of ophthalmic artery (OA). The value of ICP can be obtained by evaluating blood flow or artery characteristics in different OA segments, intracranial OA segment (IOA) and extracranial OA segment (EOA). In order to increase measurement accuracy, the systematic errors must be evaluated, which requires an implementation of a numerical model encompassing various physical phenomena. In this paper, a developed numerical model is presented, which was used to solve a transient fluid–structure interaction (FSI) problem of the pulsatile blood flow in a straight, physically meaningful anisotropic, hyperelastic OA, with ICP and external pressure (Pe) loads. It was found that the systematic error based on mean cross-sectional area difference between IOA and EOA segments was {–1.48, –1.37, –1.17} mmHg with ICP = {10, 20, 30} mmHg, respectively. The systematic error based on mean blood flow velocity difference between IOA and EOA segments was {–1.84, –1.76, –1.625} mmHg with ICP = {10, 20, 30} mmHg, respectively. The presented numerical model examined the worst-case scenario in terms of boundary conditions, which were immovable, while lengths of OA segments were physiologically relevant statistical means; however, the obtained systematic errors still met the clinical standards of ANSI/AAMI, where it is stated that the error should not exceed the ± 2 mmHg in the range of 0–20 mmHg of ICP. Boundary conditions and compliance affects the systematic error in both ways (reduce or increase it); this may explain the low systematic errors obtained in experimental studies by other authors.","PeriodicalId":35639,"journal":{"name":"Energetika","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49647072","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}

引用次数: 1