Archives of Thermodynamics最新文献_第4页

Identification of the liquid turbulent flow based on experimental methods 基于实验方法的液体湍流识别

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Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ATHER.2020.134573

Jean Talaga, P. Duda

引用次数: 1

Thermodynamic analysis of modular high-temperature nuclear reactor coupled with the steam cycle for power generation 模块化高温核反应堆和蒸汽循环耦合发电的热力学分析

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Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2019.130007

M. Dudek, M. Jaszczur, Z. Kolenda

{"title":"Thermodynamic analysis of modular high-temperature nuclear reactor coupled with the steam cycle for power generation","authors":"M. Dudek, M. Jaszczur, Z. Kolenda","doi":"10.24425/ather.2019.130007","DOIUrl":"https://doi.org/10.24425/ather.2019.130007","url":null,"abstract":"Consumption of energy is one of the important indicators in developing countries, but a lot of companies from the energy sector have to cope with three key challenges, namely how to reduce their impact on the environment, how to ensure the low cost of the energy production and how to improve the system overall performance? For Polish energy market, the number of challenges is greater. The growing demand for electricity and contemporary development of nuclear power technology allow today’s design, implement new solutions for high energy conversion system low unit cost for energy and fuel production. In the present paper, numerical analysis of modular high-temperature nuclear reactor coupled with the steam cycle for electricity production has been presented. The analysed system consists of three independent cycles. The first two are high-temperature nuclear reactor cycles which are equipped with two high-temperature nuclear reactors, heat exchangers, blowers, steam generators. The third cycle is a Rankine cycle which is equipped with up to four steam turbines, that operate in the heat recovery system. The analysis of such a system shows that is possible to achieve significantly greater efficiency than offered by traditional nuclear reactor technology.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44196171","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

Novel model for emptying of a self-pressurised nitrous oxide tank 自压一氧化二氮储罐排空的新模型

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Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2022.143176

Jakub Szymborski

{"title":"Novel model for emptying of a self-pressurised nitrous oxide tank","authors":"Jakub Szymborski","doi":"10.24425/ather.2022.143176","DOIUrl":"https://doi.org/10.24425/ather.2022.143176","url":null,"abstract":"Nitrous oxide is often used in the space industry, as an oxidiser or monopropellant, mostly in self-pressurised conﬁgurations. It has potential for growth in use due to the recent rising interest in green propellants. At the same time, modelling the behaviour of a self-pressurising nitrous oxide tank is a challenging task, and few accurate numerical models are currently available. Two-phase ﬂow, heat transfer and rapid changes of mass and temperature in the investigated system all increase the diﬃculty of accurately predicting this process. To get a get better understanding of the emptying of a self-pressurised nitrous oxide tank, two models were developed: a phase equilibrium model (single node equilibrium), treating the control volume as a single node in equilibrium state, and a phase interface model, featuring a moving interface between parts of the investigated medium. The single node equilibrium model is a variation of equilibrium model previously described in the literature, while the phase interface model involves a novel approach. The results show that the models are able to capture general trends in the main parameters, such as pressure or temperature. The phase interface model predicts nitrous oxide as a liquid, a two-phase mixture, and vapour in the lower part of the tank, which is reﬂected in the dynamics of changes in pressure and mass ﬂow rate. The models developed for self-pressurisation, while created for predicting nitrous oxide behaviour, could be adapted for other media in conditions near vapour– liquid equilibrium by adding appropriate state equations.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46341807","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 selected aspects of a tank gassing-up process on board liquefied petroleum gas carrier. Part I 液化石油气船上储罐充气过程的选定方面分析。第一部分

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Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2021.137552

A. Wieczorek

引用次数: 0

Prediction of vapor-liquid equilibrium of ternary system at high pressures 高压下三元体系汽液平衡的预测

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Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ATHER.2019.129545

S. Ray, V. Harsha, V. Raghavan

引用次数: 0

Simulation of control of lowpower-output steam turbines 低功率输出汽轮机的控制仿真

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Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2022.141975

Władysław Kryłłowicz, Jacek KARCZEWSKIb, P. Szuman, P. Szuman

引用次数: 0

Investigation and simulation based optimization of an energy storage system with pressurized air 基于仿真的增压空气储能系统优化研究

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Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2021.139658

Dirk Herbert

{"title":"Investigation and simulation based optimization of an energy storage system with pressurized air","authors":"Dirk Herbert","doi":"10.24425/ather.2021.139658","DOIUrl":"https://doi.org/10.24425/ather.2021.139658","url":null,"abstract":"As a central goal of the energy transition in Germany, the share of renewable energies is to be increased to over 80% by 2050. Due to ﬂuctuating wind conditions or the day-night cycle, storage systems must be integrated into the supply grid for a continuous regenerative power supply from wind and solar energy. In addition to pumped storage systems, batteries and Power2Gas approaches, compressed gases (optimally air) can also be used for this purpose. The aim of the research and development project presented is to develop such a storage unit with the best possible eﬃciency and long service life. To this end, basic calculations were ﬁrst made on possible eﬃciencies depending on the assumed changes in the state of the working gas. Furthermore a piston compressor for compressed air generation was investigated experimentally with regard to its eﬃciency. In addition, the compressor was modelled and simulated in a corresponding software. Thus, on the one hand, the eﬃciency of the existing piston compressor could be determined experimentally and, on the other hand, the simulation model could be assessed with regard to its suitability for the purpose of simulation-based optimization. Measures to increase eﬃciency can be derived from the results. In addition, it becomes possible to forecast the achievable overall eﬃciency of such an energy storage system with compressed air.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43220940","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

Research and development of a high-performance oxy-fuel combustion power cycle with coal gasification 煤气化高性能氧燃料燃烧动力循环的研究与开发

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2021.139656

引用次数: 3

Selection of a numerical model to predict the flowin a fan with a cycloidal rotor 摆线转子风机流量预测的数值模型选择

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Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2021.137560

M. Majkut, S. Dykas, Krystian Smołka

{"title":"Selection of a numerical model to predict the flowin a fan with a cycloidal rotor","authors":"M. Majkut, S. Dykas, Krystian Smołka","doi":"10.24425/ather.2021.137560","DOIUrl":"https://doi.org/10.24425/ather.2021.137560","url":null,"abstract":"A fan with a cycloidal rotor (CRF) is a promising design for application in HVAC (heat, ventilation and air conditioning) systems. Despite the widespread use of the CRF design as a form of propulsion, there are practically no scientiﬁc publications examining the possibility of using it as the HVAC fan. The choice of the cycloidal rotor facilitates the operating procedure and widens the range of operating conditions. The paper focuses on the use of the CRF in HVAC, especially as a blowing machine integrated with rectangular ducts, presenting, and discussing the search for the most eﬃcient numerical model. The way of discretizing the computational domain, the turbulence models and the time integration method were tested. A four-blade open rotor fan with a cycloidal impeller was used both in the numerical and in the experimental model. The 2D and 3D CRF models created in the Ansys CFX package were adopted. After a mesh-independence study, diﬀerent turbulence models were tested for the selected mesh. In the case of the 2D model, various turbulence models such as the SST and the RNG k - ε options were tested and compared with each other. The computational ﬂuid dynamics simulations were compared with in-house experimental results of the velocity ﬁeld measurements performed by means of laser Doppler anemometry and thermoanemometry. It turned out that the considered numerical models did not reﬂect the experimental measurements quantitatively. This may be due to the small diﬀerences in the shapes of the cycloids of the rotor blades in the numerical model and in real geometry.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44471302","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

Determining steam condensation pressure in a power plant condenser in off-design conditions 在非设计条件下确定发电厂冷凝器中的蒸汽冷凝压力

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2021.138109

R. Laskowski, A. Smyk, A. Ruciński, Jacek

{"title":"Determining steam condensation pressure in a power plant condenser in off-design conditions","authors":"R. Laskowski, A. Smyk, A. Ruciński, Jacek","doi":"10.24425/ather.2021.138109","DOIUrl":"https://doi.org/10.24425/ather.2021.138109","url":null,"abstract":"The paper presents formulas which can be used to determine steam condensation pressure in a power plant condenser in oﬀ-design conditions. The mathematical model provided in the paper makes it possible to calculate the performance of the condenser in terms of condensing steam pressure, cooling water temperature at the condenser outlet, and condenser eﬀectiveness under variable load conditions as a function of three input properties: the temperature and the mass ﬂow rate of cooling water at the condenser inlet and the mass ﬂow rate of steam. The mathematical model takes into account values of properties occurring in reference conditions but it contains no constant coeﬃcients which would have to be established based on data from technical speciﬁcations of a condenser or measurement data. Since there are no such constant coeﬃcients, the model of the steam condenser proposed in the paper is universally applicable. The proposed equations were checked against warranty measurements made in the condenser and measurement data gathered during the operation of a 200 MW steam power unit. Based on the analysis, a conclusion may be drawn that the proposed means of determining pressure in a condenser in oﬀ-design conditions reﬂects the condenser performance with suﬃcient accuracy. This model can be used in optimization and diagnostic analyses of the performance of a power generation unit.","PeriodicalId":45257,"journal":{"name":"Archives of Thermodynamics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44994297","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