Acta Polytechnica最新文献_第7页

Measurement of a quantum particle position at two distant locations: a model 在两个遥远的地方测量量子粒子的位置:一个模型

IF 0.8

Acta Polytechnica Pub Date : 2022-08-31 DOI: 10.14311/ap.2022.62.0445

J. Dittrich

引用次数: 0

CFD simulation of partial channel blockage on plate-type fuel of TRIGA-2000 conversion reactor core TRIGA-2000型转换堆堆芯板型燃料部分通道堵塞的CFD模拟

IF 0.8

Acta Polytechnica Pub Date : 2022-08-31 DOI: 10.14311/ap.2022.62.0438

S. Dibyo, W. Luthfi, S. Pinem, I. Irianto, Veronica Indriati Sriwardhani

{"title":"CFD simulation of partial channel blockage on plate-type fuel of TRIGA-2000 conversion reactor core","authors":"S. Dibyo, W. Luthfi, S. Pinem, I. Irianto, Veronica Indriati Sriwardhani","doi":"10.14311/ap.2022.62.0438","DOIUrl":"https://doi.org/10.14311/ap.2022.62.0438","url":null,"abstract":"A nuclear reactor cooling system that has been operating for a long time can carry some debris into a fuel coolant channel, which can result in a blockage. An in-depth two-dimensional simulation of partial channel blockage can be carried out using FLUENT Code. In this study, a channel blockage simulation is employed to perform a safety analysis for the TRIGA-2000 reactor, which is converted using plate-type fuel. Heat generation on the fuel plate takes place along its axial axis. The modelling of the fuel-plate is in the form of a rectangular sub-channel with an inlet coolant temperature of 308 K with a low coolant velocity of 0.69 m/s. It is assumed that blockage is in a form of a thin plate, with the blockage area being assumed to be 60 %, 70 %, and 80 % at the sub-channel inlet flow. An unblocking condition is also compared with a steady-state calculation that has been done by COOLOD-N2 Code. The results show that a partial blockage has a significant impact on the coolant velocity. When the blockage of 80 % occurs, a maximum coolant temperature locally reaches 413 K. While the saturation temperature is 386 K. From the point of view of the safety aspect, the blockage simulation result for the TRIGA-2000 thermal-hydraulic core design using plate-type fuel shows that a nucleate boiling occurs, which from the safety aspect, could cause damage to the fuel plate.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42639152","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

Functional aerodynamics and its influence on the energy and thermal mode of a naturally ventilated double-skin transparent façade 功能空气动力学及其对自然通风双层透明立面能量和热模式的影响

IF 0.8

Acta Polytechnica Pub Date : 2022-08-31 DOI: 10.14311/ap.2022.62.0459

M. Franek, B. Bielek, M. Macák, J. Klem

引用次数: 0

Evaluation of residual strength of polymeric yarns subjected to previous impact loads 聚合物纱线在先前冲击载荷下的残余强度评估

IF 0.8

Acta Polytechnica Pub Date : 2022-08-31 DOI: 10.14311/ap.2022.62.0473

G. Hahn, Antônio Henrique Monteiro da Fonseca Thomé da Silva, Felipe Tempel Stumpf, Carlos Eduardo Marcos Guilherme

引用次数: 0

Evaluation of activity concentration of 40 K, 226Ra and 232Th and radiological hazards in commercial wall paints used in Nigeria 尼日利亚商用墙漆中40k、226Ra和232Th活性浓度及其辐射危害的评价

IF 0.8

Acta Polytechnica Pub Date : 2022-08-08 DOI: 10.1007/s41050-022-00037-1

E. Echeweozo

引用次数: 0

Effect of membrane separation process conditions on the recovery of syngas components 膜分离工艺条件对合成气组分回收的影响

IF 0.8

Acta Polytechnica Pub Date : 2022-06-30 DOI: 10.14311/ap.2022.62.0394

P. Seghman, L. Krátký, T. Jirout

{"title":"Effect of membrane separation process conditions on the recovery of syngas components","authors":"P. Seghman, L. Krátký, T. Jirout","doi":"10.14311/ap.2022.62.0394","DOIUrl":"https://doi.org/10.14311/ap.2022.62.0394","url":null,"abstract":"The presented study focuses on inspecting the dependency between process conditions, especially permeate and retentate pressure and component recovery of H2, CO, and CO2 during a membrane separation of model syngas. Experiments with both pure components and a model mixture were performed using a laboratory membrane unit Ralex GSU-LAB-200 with a polyimide hollow fibre module with 3000 hollow fibres. Permeability values were established at 1380 Barrer for H2, 23 Barrer for CO, and 343 Barrer for CO2. The measured selectivities differ from the ideal ones: the ideal H2/CO2 selectivity is 3.21, while the experimental values range from over 4 to as low as 1.2 (this implies that an interaction between the components occurs). Then, the model syngas, comprised of 16% H2, 34% CO, and 50% CO2, was tested. The recovery of each component decreases with an increasing permeate pressure. At a pressure difference of 2 bar, the recovery rate for H2, for a permeate pressure of 1.2 bar, is around 68%, for 2.5 bar, the values drop to 51%, and for 4 bar, the values reach 40% only. A similar trend was observed for CO2, with recovery values of 59%, 47% and 37% for permeate pressures of 1.2 bar, 2.5 bar and 4 bar, respectively.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45211355","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

Experimental and simulation study of CO2 breakthrough curves in a fixed-bed adsorption process 固定床吸附过程中CO2突破曲线的实验与模拟研究

IF 0.8

Acta Polytechnica Pub Date : 2022-06-30 DOI: 10.14311/ap.2022.62.0370

M. Nedoma, M. Staf, J. Hrdlička

引用次数: 1

Experimental verification of the efficiency of selective non-catalytic reduction in a bubbling fluidized bed combustor 鼓泡流化床燃烧器选择性非催化还原效率的实验验证

IF 0.8

Acta Polytechnica Pub Date : 2022-06-30 DOI: 10.14311/ap.2022.62.0361

Kristýna Michaliková, J. Hrdlička, Matěj Vodička, Pavel Skopec, Jitka Jeníková, L. Pilař

{"title":"Experimental verification of the efficiency of selective non-catalytic reduction in a bubbling fluidized bed combustor","authors":"Kristýna Michaliková, J. Hrdlička, Matěj Vodička, Pavel Skopec, Jitka Jeníková, L. Pilař","doi":"10.14311/ap.2022.62.0361","DOIUrl":"https://doi.org/10.14311/ap.2022.62.0361","url":null,"abstract":"Controlling nitrogen oxide (NOX) emissions is still a challenge as increasingly stringent emission limits are introduced. Strict regulations will lead to the need to introduce secondary measures even for boilers with bubbling fluidized bed (BFB), which are generally characterized by low NOX emissions. Selective non-catalytic reduction has lower investment costs compared to other secondary measures for NOX reduction, but the temperatures for its efficient utilization are difficult to achieve in BFBs. This paper studies the possibility of an effective application of selective non-catalytic reduction (SNCR) of nitrogen oxides in a pilot-scale facility with a bubbling fluidized bed. The effect of temperatures between 880 and 950 °C in the reagent injection zone on NOX reduction was investigated. For the selected temperature, the effect of the amount of injected reagent, urea solution with concentration 32.5%wt., was studied. The experiments were carried out using 500 kWth pilot scale BFB unit combusting lignite. In addition, an experiment was performed with the combustion of wooden pellets. With reagent injection, all experiments led to the reduction of nitrogen oxides and the highest NOX reduction of 58% was achieved.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43068605","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

Experimental verification of the impact of the air staging on the NOx production and on the temperature profile in a BFB 空气分级对BFB中NOx生成和温度分布影响的实验验证

IF 0.8

Acta Polytechnica Pub Date : 2022-06-30 DOI: 10.14311/ap.2022.62.0400

Matěj Vodička, Kristýna Michaliková, J. Hrdlička, Pavel Skopec, Jitka Jeníková

{"title":"Experimental verification of the impact of the air staging on the NOx production and on the temperature profile in a BFB","authors":"Matěj Vodička, Kristýna Michaliková, J. Hrdlička, Pavel Skopec, Jitka Jeníková","doi":"10.14311/ap.2022.62.0400","DOIUrl":"https://doi.org/10.14311/ap.2022.62.0400","url":null,"abstract":"The results of an experimental research on air staging in a bubbling fluidized bed (BFB) combustor are presented within this paper. Air staging is known as an effective primary measure to reduce NOX formation. However, in the case of a number of industrial BFB units, it does not have to be sufficient to meet the emission standards. Then selective non-catalytic reduction (SNCR) can be a cost-effective option for further reduction of the already formed NOX. The required temperature range at the place of the reducing agent injection for an effective application of the SNCR without excessive ammonia slip is above the temperatures normally attained in BFBs. The aim of this paper is to evaluate the impact of staged air injection on the formation of NOX in BFB combustors and to examine the possibility of increasing the freeboard temperature. Several experiments with various secondary/primary air ratios were performed with a constant oxygen concentration in the flue gas. The experiments were carried out using wooden biomass and lignite as fuel in a 30 kWth laboratory scale BFB combustor. Furthermore, the results were verified using a 500 kWth pilot scale BFB unit. The results confirmed that the air staging can effectively move the dominant combustion zone from the dense bed to the freeboard section, and thus the temperatures for an effective application of the SNCR can be obtained.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46017709","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

Analysis of parameters important for indirect drying of biomass fuel 生物质燃料间接干燥的重要参数分析

IF 0.8

Acta Polytechnica Pub Date : 2022-06-30 DOI: 10.14311/ap.2022.62.0386

M. Sabatini, J. Havlík, T. Dlouhý

{"title":"Analysis of parameters important for indirect drying of biomass fuel","authors":"M. Sabatini, J. Havlík, T. Dlouhý","doi":"10.14311/ap.2022.62.0386","DOIUrl":"https://doi.org/10.14311/ap.2022.62.0386","url":null,"abstract":"This paper focuses on biomass drying for the design and operation of an indirect dryer used in a biomass power plant. Indirect biomass drying is not as well described process as direct drying, especially when used for the preparation of biomass in energy processes, such as combustion or gasification. Therefore, it is necessary to choose a suitable model describing the drying process and evaluate its applicability for this purpose. The aim of this paper is to identify parameters that most significantly affect the indirect drying process of biomass for precise targeting of future experiments. For this purpose, the penetration model was chosen. The penetration model describes indirect drying through 21 parameters. To run a series of experiments focused on all parameters would be time consuming. Therefore, the easier way is to select the most important parameters through a sensitivity analysis, and then perform experiments focused only on the significant parameters The parameters evaluated as significant are the temperature of the heated wall, operating pressure in the drying chamber, surface coverage factor, emissivity of the heated wall, emissivity of the bed, diameter of the particle, and particle surface roughness. Due to the presumption of perfect mixing of the material being dried, stirrer speed is added into important parameters. Based on these findings, it will be possible to reduce the scope of experiments necessary to verify the applicability of the penetration model for the description of indirect biomass drying and the design of dryers for a practical use.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43273873","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