Archives of Thermodynamics最新文献_第8页

Transient heat transfer as a leading factor in fatigue of thick-walled elements at power plants 瞬态传热是电厂厚壁元件疲劳的主要因素

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ATHER.2019.129549

K. Wacławiak, J. Okrajni

引用次数: 2

Design and development of smokeless stove for a sustainable growth 可持续发展无烟炉灶的设计与开发

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2022.140927

R. Nayak

{"title":"Design and development of smokeless stove for a sustainable growth","authors":"R. Nayak","doi":"10.24425/ather.2022.140927","DOIUrl":"https://doi.org/10.24425/ather.2022.140927","url":null,"abstract":"Air pollution has a serious impact on the health of human beings and is a major cause of death worldwide every year. Out of the many sources of air pollution, the smoke generated from household combustion devices is very dangerous due to the incomplete combustion of fuel. Women from rural areas suﬀer a lot due to this harmful smoke. Diseases like cancer, throat, and lung infection occur in adults and children due to inhalation of this smoke. The traditional chulha used by rural women is operated by using cow dung, straw, and wood, and the air is blown manually by using small metallic pipes. This paper presents the design and development of an innovative stove to maximize ﬂame temperature and minimize air pollution to overcome the health-related issues of rural women. A smokeless stove is presented, in which wood, straw, and cow dung are taken as primary fuel, and superheated steam as a secondary oxidizer for its operation. In this stove, a forced draft is created by the provision of a small fan, which is operated by solar power thus eliminating the need of creating a forced draft manually by the cook which makes this innovative stove superior to the traditional chulha. Owing to the provision of superheated steam, the ﬂame temperature as well as the burning eﬃciency increases. The cooking time is reduced due to higher ﬂame temperature as compared to the liqueﬁed petroleum gas stove. The main objective of this work is to minimize air pollution and provide a smoke-free environment to the people using such","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48853225","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

Subcooled flow boiling of a citric acid aqueous mixture 柠檬酸水混合物的过冷流动沸腾

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2020.132955

Mohammad Amin Abdolhossein Zadeh, S. Nakhjavani

{"title":"Subcooled flow boiling of a citric acid aqueous mixture","authors":"Mohammad Amin Abdolhossein Zadeh, S. Nakhjavani","doi":"10.24425/ather.2020.132955","DOIUrl":"https://doi.org/10.24425/ather.2020.132955","url":null,"abstract":"In the present research, an experimental investigation was conducted to assess the heat transfer coefficient of aqueous citric acid mixtures. The experimental facility provides conditions to assess the influence of various operating conditions such as the heat flux (0–190 kW/m), mass flux (353–1059 kg/ms) and the concentration of citric acid in water (10%– 50% by volume) with a view to measure the subcooled flow boiling heat transfer coefficient of the mixture. The results showed that two main heat transfer mechanisms can be identified including the forced convective and nucleate boiling heat transfer. The onset point of nucleate boiling was also identified, which separates the forced convective heat transfer domain from the nucleate boiling region. The heat transfer coefficient was found to be higher in the nucleate boiling regime due to the presence of bubbles and their interaction. Also, the influence of heat flux on the heat transfer coefficient was more pronounced in the nucleate boiling heat transfer domain, which was also attributed to the increase in bubble size and rate of bubble formation. The obtained results were also compared with those theoretically obtained using the Chen type model and with some experimental data reported in the literature. Results were within a fair agreement of 22% against the Chen model and within 15% against the experimental data.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44292816","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

Impact of hydrogen blended natural gas on linepack energy for existing high pressure pipelines 掺氢天然气对现有高压管道线路包能量的影响

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2022.143174

M. Witek, F. Uilhoorn

{"title":"Impact of hydrogen blended natural gas on linepack energy for existing high pressure pipelines","authors":"M. Witek, F. Uilhoorn","doi":"10.24425/ather.2022.143174","DOIUrl":"https://doi.org/10.24425/ather.2022.143174","url":null,"abstract":"The aim of this work is to examine the impact of the hydrogen blended natural gas on the linepack energy under emergency scenarios of the pipeline operation. Production of hydrogen from renewable energy sources through electrolysis and subsequently injecting it into the natural gas network, gives ﬂexibility in power grid regulation and the energy storage. In this context, knowledge about the hydrogen percentage content, which can safely eﬀect on materials in a long time steel pipeline service during transport of the hydrogen-natural gas mixture, is essential for operators of a transmission network. This paper ﬁrst reviews the allowable content of hydrogen that can be blended with natural gas in existing pipeline systems, and then investigates the impact on linepack energy with both startup and shutdown of the compressors scenarios. In the latter case, an unsteady gas ﬂow model is used. To avoid spurious oscillations in the solution domain, a ﬂux limiter is applied for the numerical approximation. The GERG-2008 equation of state is used to calculate the physical properties. For the case study, a tree-topological high pressure gas network, which have been in-service for many years, is selected. The outcomes are valuable for pipeline operators to assess the security of supply.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44541376","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: 2

Numerical investigation of biomass fast pyrolysis in a free fall reactor 自由落体反应器中生物质快速热解的数值研究

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2021.138115

A. Bieniek, W. Jerzak, A. Magdziarz

{"title":"Numerical investigation of biomass fast pyrolysis in a free fall reactor","authors":"A. Bieniek, W. Jerzak, A. Magdziarz","doi":"10.24425/ather.2021.138115","DOIUrl":"https://doi.org/10.24425/ather.2021.138115","url":null,"abstract":"This work presents two-dimensional numerical investigations of fast pyrolysis of red oak in a free fall reactor. The Euler–Lagrange approach of multiphase ﬂow theory was proposed in order to describe the behaviour of solid particles in the gaseous domain. The main goal of this study was to examine the impact of the ﬂow rate of inert gas on the pyrolysis process. Calculation domain of the reactor was made according to data found in the literature review. Volume ﬂow rates were 3, 9, 18, and 25 l/min, respectively. Nitrogen was selected as an inert gas. Biomass pyrolysis was conducted at 550 ◦ C with a constant mass ﬂow rate of biomass particles equal to 1 kg/h. A parallel multistage reaction mechanism was applied for the thermal conversion of red oak particles. The composition of biomass was represented by three main pseudo-components: cellulose, hemicellulose and lignin. The received products of pyrolysis were designated into three groups: solid residue (char and unreacted particles), primary tars and non-condensable gases. In this work the impact of the volume ﬂow rate on the heating time of solid particle, temperature distribution, yields and char mass fraction has been analysed. The numerical solutions were veriﬁed according to the literature results when the ﬂow of nitrogen was set at 18 l/min. The calculated results showed that biomass particles could be heated for longer when the ﬂow rate of nitrogen was reduced, allowing for a greater concentration of volatile matter.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44584263","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

Simulation and numerical analysis of a rectangular pipe with transversal baffle – comparison between zigzag and plane baffles 矩形管横向折流板的仿真与数值分析——之字形折流板与平面折流板的比较

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2020.135988

C. Zidani

引用次数: 1

Utilization of organic Rankine cycles in a cogeneration system with a high-temperature gas-cooled nuclear reactor – thermodynamic analysis 有机朗肯循环在高温气冷核反应堆热电联产系统中的应用——热力学分析

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2021.137554

J. Jędrzejewski

{"title":"Utilization of organic Rankine cycles in a cogeneration system with a high-temperature gas-cooled nuclear reactor – thermodynamic analysis","authors":"J. Jędrzejewski","doi":"10.24425/ather.2021.137554","DOIUrl":"https://doi.org/10.24425/ather.2021.137554","url":null,"abstract":"The paper presents results of a parametric analysis of a high-temperature nuclear-reactor cogeneration system. The aim was to investigate the power eﬃciency of the system generating heat for a high-temperature technological process and electricity in a Brayton cycle and additionally in organic Rankine cycles using R236ea and R1234ze as working ﬂuids. The results of the analyses indicate that it is possible to combine a 100 MW high-temperature gas-cooled nuclear reactor with a technological process with the demand for heat ranging from 5 to 25 MW, where the required temperature of the process heat carrier is at the level of 650 ◦ C. Calculations were performed for various pressures of R236ea at the turbine inlet. The cogeneration system maximum power eﬃciency in the analysed cases ranges from ~35.5% to ~45.7% and the maximum share of the organic Rank-ine cycle systems in electric power totals from ~26.9% to ~30.8%. If such a system is used to produce electricity instead of conventional plants, carbon dioxide emissions can be reduced by about 216.03–147.42 kt/year depending on the demand for process heat, including the reduction achieved in the organic Rankine cycle systems by about 58.01–45.39 kt/year (in Poland).","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43940350","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

Turbine stage expansion model including internal air film cooling and novel method of calculating theoretical power of a cooled stage 包括内气膜冷却在内的涡轮级膨胀模型和计算冷却级理论功率的新方法

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2022.143169

Paweł Trawiński

{"title":"Turbine stage expansion model including internal air film cooling and novel method of calculating theoretical power of a cooled stage","authors":"Paweł Trawiński","doi":"10.24425/ather.2022.143169","DOIUrl":"https://doi.org/10.24425/ather.2022.143169","url":null,"abstract":"Systematic attempts to maximise the eﬃciency of gas turbine units are achieved, among other possibilities, by increasing the temperature at the inlet to the expansion section. This requires additional technological solutions in advanced systems for cooling the blade rows with air extracted from the compressor section. This paper introduces a new mathematical model describing the expansion process of the working medium in the turbine stage with air ﬁlm cooling. The model includes temperature and pressure losses caused by the mixing of cooling air in the path of hot exhaust gases. The improvement of the accuracy of the expansion process mathematical description, compared with the currently used models, is achieved by introducing an additional empirical coeﬃcient estimating the distribution of the cooling air along the proﬁle of the turbine blade. The new approach to determine the theoretical power of a cooled turbine stage is also presented. The model is based on the application of three conservation laws: mass, energy and momentum. The advantage of the proposed approach is the inclusion of variable thermodynamic parameters of the cooling medium. The results were compared with the simpliﬁed models used in the literature: separate Hartsel expansion, mainstream pressure, weighted-average pressure and fully reversible. The proposed model for expansion and the determination of theoretical power allows for accurate modelling of the performance of a cooled turbine stage under varying conditions.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45125394","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

A comprehensive review on energy and exergy analysis of solar air heaters 太阳能空气加热器的能量与火用分析综述

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2020.134577

Harish Kumar Ghritlahre, P. Sahu

{"title":"A comprehensive review on energy and exergy analysis of solar air heaters","authors":"Harish Kumar Ghritlahre, P. Sahu","doi":"10.24425/ather.2020.134577","DOIUrl":"https://doi.org/10.24425/ather.2020.134577","url":null,"abstract":"For economic growth of nation, the energy plays an important role. The excessive use of fossil fuels results the increase in global warming and depleting the resources. Due to this reason, the renewable energy sources are creating more attraction for researchers. In renewable energy sector, solar energy is the most abundant and clean source of energy. In solar thermal systems, solar air heater (SAH) is the main system which is used for heating of air. As it is simple in construction and cheaper in cost, it is of main interest for the researchers. The concept of ﬁrst law and second law of thermodynamics is used for the study of the energy and exergy analysis respectively. The energy analysis is of great importance for the study of process eﬀectiveness while the exergetic analysis is another significant concept to examine the actual behavior of process involving various energy losses and internal irreversibility. For eﬃcient utilization of solar energy, the exergy analysis is very important tool for optimal design of solar air heaters. The aim of the present work is to review the works related to energy and exergy analysis of various types of solar air heaters and to ﬁnd out the research gap for future work.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48367440","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: 7

Identification of unsteady effects in the flow through a centrifugal fan using CFD/CAA methods 利用CFD/CAA方法识别离心风机流动中的非定常效应

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2021.139657

引用次数: 1