Archives of Thermodynamics最新文献_第6页

Triple diffusive flow of Casson nanofluid with buoyancy forces and nonlinear thermal radiation over a horizontal plate 具有浮力和非线性热辐射的卡森纳米流体在水平板上的三重扩散流动

Archives of Thermodynamics Pub Date : 2023-07-26 DOI: 10.24425/ather.2019.128289

Manjappa Archana, Bijjanal Jayanna Gireesha, Ballajja Chandrappa Prasannakumara

引用次数: 28

Economic effectiveness evaluation of the free piston Stirling engine-based micro-combined heat and power unit in relation to classical systems 基于自由活塞斯特林发动机的微型热电联产机组与经典系统的经济性评价

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2019.128290

W. Uchman, L. Remiorz, J. Kotowicz

{"title":"Economic effectiveness evaluation of the free piston Stirling engine-based micro-combined heat and power unit in relation to classical systems","authors":"W. Uchman, L. Remiorz, J. Kotowicz","doi":"10.24425/ather.2019.128290","DOIUrl":"https://doi.org/10.24425/ather.2019.128290","url":null,"abstract":"In this article, a comparison of economic effectiveness of various heating systems dedicated to residential applications is presented: a natural gas-fueled micro-cogeneration (micro-combined heat and power – μCHP) unit based on a free-piston Stirling engine that generates additional electric energy; and three so-called classical heating systems based on: gas boiler, coal boiler, and a heat pump. Calculation includes covering the demand for electricity, which is purchased from the grid or produced in residential system. The presented analyses are partially based on an experimental investigation. The measurements of the heat pump system as well as those of the energy (electricity and heat) demand profiles in the analyzed building were conducted for a single-family house. The measurements of the μCHP unit were made using a laboratory stand prepared for simulating a variable heat demand. The overall efficiency of the μCHP was in the range of 88.6– 92.4%. The amounts of the produced/consumed energy (electricity, heat, and chemical energy of fuel) were determined. The consumption and the generation of electricity were settled on a daily basis. Operational costs of the heat pump system or coal boiler based heating system are lower comparing to the micro-cogeneration, however no support system for natural gas-based μCHP system is included.","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":"44922308","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

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":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":"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

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

IF 0.9

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

IF 0.9

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":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":"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

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

IF 0.9

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

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

IF 0.9

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

Jean Talaga, P. Duda

引用次数: 1

Diffusive–inertial droplet separation model from two-phase flow 两相流中的扩散-惯性液滴分离模型

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2021.138113

引用次数: 0

Quantity and quality of marine dual-fuel engine’s exhaust sensible waste heat considering different sulfur content in fuels 考虑不同燃料含硫量的船用双燃料发动机排气显余热的数量和质量

IF 0.9

Archives of Thermodynamics Pub Date : 2023-07-20 DOI: 10.24425/ather.2020.135857

M. Przybyła

{"title":"Quantity and quality of marine dual-fuel engine’s exhaust sensible waste heat considering different sulfur content in fuels","authors":"M. Przybyła","doi":"10.24425/ather.2020.135857","DOIUrl":"https://doi.org/10.24425/ather.2020.135857","url":null,"abstract":"Maritime transport is facing a set of technical challenges due to implementation of ecological criterions on 1st Jan. 2020 and 2021 by the International Maritime Organization. The advantageous properties of natural gas (NG) as fuel in conjunction with dual-fuel (DF) internal combustion engines (ICE) potentially enables the fulfilment of all criterions. Moreover the 2020 global sulfur cap in combination with its low content in NG potentially enables to recover higher rates of waste heat and exergy of exhaust gas without the risk of low temperature corrosion. In this study the influence of sulfur content in NG and pilot fuel oil (PFO) on the sulfuric acid condensation temperature was investigated in order to determine the rate of waste heat (quantity) and exergy (quality) of four-stroke DF IC engine’s exhaust for 50%, 85% and 100% of engine load. Determined parameters were compared with two sets of reference values calculated for the same engine: a) fueled with NG and PFO with fixed minimum exhaust temperature set as 423.15 K, b) fueled with 3.5% sulfur mass fraction fuel oil only with variable minimum exhaust gas temperature. The results show that the assumption of case a) can lead to significant reduction of recovered rates of exhaust waste heat and exergy in the ranges of 10% to 24% and 43% to 57%, respectively. Higher values were obtained for case b) where the ranges of unrecovered rate of heat and exergy achieved 20% to 38% and 60% to 70%.","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":"47004268","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