1. Evaluation of system for economically viable thermal power plant operationMartin Bricl, Jurij Avsec, 2019, izvirni znanstveni članek Opis: Taking into consideration the impacts of global warming and strict European Union policy 2030 climate & energy framework, it is imminent for conventional thermal power plants to modernize their infrastructure for achieving economically viable operation on demanding electricity market. In the scope of the paper is presented author%s individual research work - economic evaluation of conventional thermal power plant operation with solar central receiver system and flue gas desulphurization installation. The goal of research work is to determine whether the designed model is profitable on current European electricity market or not. Based on analytical calculations and gathered numerical data for the designed model, a program code was generated in mathematical environment Matlab, that enables simulation of operation for the designed model in the annual time period. Positive and pessimistic scenarios were analyzed. Results are presented numerically and also graphically and show a positive contribution to the economically viable operation of conventional thermal power plants. Ključne besede: thermal power plant, economically viable operation, a solar central receiver system, renewable technologies, flue gas desulphurization Objavljeno v DKUM: 22.02.2024; Ogledov: 360; Prenosov: 21
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2. Converting waste into products and energy using complete circular economy and the hydrogen effect technique to reduce dependence on natural gasAnita Kovač Kralj, 2023, izvirni znanstveni članek Opis: Conversion of waste into products and energy has the potential to reduce CO2 emis-sion through implementation of a complete circular economy and utilisation of the hy-drogen effect technique. This study considers the novelties of the hydrogen effect tech-nique, which incorporates an upgraded input unit mathematical model. It includes real-simulated results obtained using an Aspen Plus & REG; simulator, and enlarged production. This technique is developed for optimal municipal solid waste (MSW) combustion, gas-ification, and reforming, presented as an upgraded input unit for syngas production, which can reduce CO2 emissions by 3 & BULL;106 kmol a-1. This approach is exemplified by utilizing existing methanol and dimethyl ether production processes from natural gas, as they can be achieved and exceeded using MSW with varying hydrogen amounts. The optimal upgraded methanol and dimethyl ether production processes can increase pro-duction by 47 % and 16 %, including only the upgraded input unit, as well as decrease the temperature in the product reactors by 30 & DEG;C. Ključne besede: waste gasification, flue gas, syngas, hydrogen, circular economy, combustion Objavljeno v DKUM: 13.02.2024; Ogledov: 320; Prenosov: 28
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3. Numerical modeling of two-phase flow inside a wet flue gas absorber sumpNejc Vovk, Jure Ravnik, 2023, izvirni znanstveni članek Opis: A numerical model of a flue gas scrubber sump is developed with the aim of enabling optimization of the design of the sump in order to reduce energy consumption. In this model, the multiphase flow of the continuous phase, i.e., water, and the dispersed phase, i.e., air bubbles, is considered. The air that is blown in front of the agitators, as well as the influence of the flow field of the agitators on the distribution of the dispersed phase and the recirculation pumps as outlet, is modeled. The bubble Sauter mean diameter is modeled using the population balance model. The model is used to analyze operating parameters such as the bubble retention time, the average air volume fraction, bubble Sauter mean diameter, the local distribution of the bubble size and the amount of air escaping from the pump outlets at two operating points. The purpose of the model is to simulate the two-phase flow in the sump of the flue gas scrubber using air dispersion technology with a combination of spargers and agitators, which, when optimized, reduces energy consumption by 33%. The results show that the homogeneity of air is lower in the bottom part of the absorber sump and that the amount of air escaping through recirculation pipes equals 1.2% of the total air blown into the absorber sump. The escaping air consists mainly of bubbles smaller than 6 mm. Additional operating point results show that halving the magnitude of the linear momentum source lowers the air retention, as well as the average homogeneity of the dispersed air Ključne besede: flue gas scrubbing, air dispersion, numerical model, OpenFoam Objavljeno v DKUM: 19.12.2023; Ogledov: 359; Prenosov: 36
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4. Limestone purity as the decisive factor for its consumption in the flue gas desulphurisation processMartin Bricl, 2021, izvirni znanstveni članek Opis: The wet flue gas cleaning process in thermal power plants uses limestone reagent, which is ground and mixed with process water, before coming in contact with flue gases, in order to form a homogeneous suspension, which then absorbs the gaseous acid components in the flue gas cleaning process in thermal power plants (mainly sulphur dioxide) from the flue gas stream. The purity of the limestone has a significant effect on its consumption, as cleaner limestone enables the absorption of a larger amount of acidic components from the flue gas stream, with lower total consumption of the reagent - i.e. limestone. Ključne besede: flue gas desulphurisation, limestone, limestone purity, limestone consumption Objavljeno v DKUM: 13.11.2023; Ogledov: 501; Prenosov: 6
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5. HRSG system description and water-steam analysis at the HRSG cold start-upDušan Strušnik, 2021, izvirni znanstveni članek Opis: The basic purpose of this paper is to present the HRSG system description in detail and possibility analysis of preventing the HRSH water-steam generated release into the atmosphere through the sky valves during the HRSG cold start-up. The steam released into the atmosphere by the cross sky valve is not an adequate solution for the following reasons: Noise prevention, water losses, thermal heat release into the environment, etc. In this paper, the possibilities and solutions are investigated in order to avoid the HRSG start-up sky venting. For this purpose, the steam quality data at HRSG cold start-up is analysed, and the possibility is examined of discharging the HRSG generated steam at the start-up via a new start-up pipeline into the existing dump condenser, or into the start-up flash tank or into the blowdown tank. The results show that, at the first 3 minutes of cold start-up, the HRSG generated only water, and this water should not be discharged into the HP or IP pipeline headers. The HRSG generates a mixture of water and steam only after 4 minutes from the start-up. For that reason it is not recommended to drain the water-steam mixture at the HRSG start-up into the new start-up pipeline, but it is recommended to drain the water and steam mixture formed during the HRSG start-up into the new start-up flash tank, or into the blowdown tank. The flash tank, and also the blowdown tank, should be appropriately dimensioned. Ključne besede: boiler, duct, flue gas, heat recovery, stack, steam generator, superheater Objavljeno v DKUM: 13.11.2023; Ogledov: 427; Prenosov: 7
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6. Small wood pellet boiler 3-D CFD study for improved flue gas emissions employing flue gas recirculation and air stagingFilip Kokalj, Tomas Zadravec, Aleksandar M. Jovović, Niko Samec, 2023, izvirni znanstveni članek Ključne besede: CFD, combustion, wood pellets, air staging, flue gas recirculation Objavljeno v DKUM: 05.09.2023; Ogledov: 391; Prenosov: 14
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