Exergy, An International Journal最新文献

Thermodynamic analysis of Belousov–Zhabotinski systems with four or five independent variables 具有四个或五个自变量的Belousov-Zhabotinski系统的热力学分析

Exergy, An International Journal Pub Date : 2002-01-01 DOI: 10.1016/S1164-0235(02)00091-2

Giacomo Bisio, Giuseppe Rubatto

{"title":"Thermodynamic analysis of Belousov–Zhabotinski systems with four or five independent variables","authors":"Giacomo Bisio, Giuseppe Rubatto","doi":"10.1016/S1164-0235(02)00091-2","DOIUrl":"10.1016/S1164-0235(02)00091-2","url":null,"abstract":"<div><p>This paper deals with a thermodynamic analysis of Belousov–Zhabotinski systems and similar ones with four or five independent variables, based on some experimental results obtained in our laboratory with a Rayleigh–Bénard cell. The new variable, never before considered in similar analyses is the relative extent of the chemical potential difference between two next layers in these Belousov–Zhabotinski systems. The mathematical approach shows some differences with regards to the traditional one. These analyses can be applied both to non-living and also to several cases of living systems. It is to be remarked that up to recent years, the researchers thought that the reactions, which take place in test-tubes and in the several laboratory vessels, could not show oscillations that are common in other fields of science. Consequently the oscillations, which were found in the Belousov–Zhabotinski systems, had a great momentum from a theoretical, even if not from a practical point of view. The analysis of Glansdorff and Prigogine was one of the motivations of this study.</p></div>","PeriodicalId":100518,"journal":{"name":"Exergy, An International Journal","volume":"2 4","pages":"Pages 361-372"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1164-0235(02)00091-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74429971","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

How far we have come? 我们走了多远?

Exergy, An International Journal Pub Date : 2002-01-01 DOI: 10.1016/S1164-0235(01)00052-8

Marc A. Rosen (Associate Editor)

引用次数: 4

Performance comparison of an irreversible closed Brayton cycle under maximum power density and maximum power conditions 最大功率密度和最大功率条件下不可逆闭合布雷顿循环的性能比较

Exergy, An International Journal Pub Date : 2002-01-01 DOI: 10.1016/S1164-0235(02)00070-5

Lingen Chen , Junlin Zheng , Fengrui Sun , Chih Wu

{"title":"Performance comparison of an irreversible closed Brayton cycle under maximum power density and maximum power conditions","authors":"Lingen Chen , Junlin Zheng , Fengrui Sun , Chih Wu","doi":"10.1016/S1164-0235(02)00070-5","DOIUrl":"10.1016/S1164-0235(02)00070-5","url":null,"abstract":"<div><p>In this paper, the power density, defined as the ratio of power output to the maximum specific volume in the cycle, is taken as objective for performance analysis of an irreversible closed Brayton cycle coupled to constant-temperature heat reservoirs in the viewpoint of finite time thermodynamics (FTT) or entropy generation minimization (EGM). The analytical formulas about the relations between power density and pressure ratio are derived with the heat resistance losses in the hot- and cold-side heat exchangers and the irreversible compression and expansion losses in the compressor and turbine. The obtained results are compared with those results obtained by using the maximum power criterion. The influences of some design parameters on the maximum power density are provided by numerical examples, and the advantages and disadvantages of maximum power density design are analyzed. The power plant design with maximum power density leads to a higher efficiency and smaller size. However, the maximum power density design requires a higher pressure ratio than maximum power design. When the heat transfer is carried out ideally, the results of this paper become those obtained in recent literature.</p></div>","PeriodicalId":100518,"journal":{"name":"Exergy, An International Journal","volume":"2 4","pages":"Pages 345-351"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1164-0235(02)00070-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80927700","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: 17

Power, power density and efficiency optimization of an endoreversible Braysson cycle 内可逆Braysson循环的功率、功率密度和效率优化

Exergy, An International Journal Pub Date : 2002-01-01 DOI: 10.1016/S1164-0235(02)00093-6

Tong Zheng , Lingen Chen , Fengrui Sun , Chih Wu

引用次数: 26

Dynamic simulation of CaO/Ca(OH)2 chemical heat pump systems CaO/Ca(OH)2化学热泵系统的动态模拟

Exergy, An International Journal Pub Date : 2002-01-01 DOI: 10.1016/S1164-0235(01)00035-8

S. Fujimoto , E. Bilgen , H. Ogura

引用次数: 27

Second law analysis of heat transfer and fluid flow inside a cylindrical annular space 圆柱环形空间内传热和流体流动的第二定律分析

Exergy, An International Journal Pub Date : 2002-01-01 DOI: 10.1016/S1164-0235(02)00078-X

Shohel Mahmud, Roydon Andrew Fraser

引用次数: 48

The exergy flux of radiative heat transfer for the special case of blackbody radiation 黑体辐射特殊情况下辐射传热的能量通量

Exergy, An International Journal Pub Date : 2002-01-01 DOI: 10.1016/S1164-0235(01)00040-1

S.E. Wright , M.A. Rosen , D.S. Scott , J.B. Haddow

{"title":"The exergy flux of radiative heat transfer for the special case of blackbody radiation","authors":"S.E. Wright , M.A. Rosen , D.S. Scott , J.B. Haddow","doi":"10.1016/S1164-0235(01)00040-1","DOIUrl":"10.1016/S1164-0235(01)00040-1","url":null,"abstract":"<div><p>Exergy analysis is a highly effective method of analysis for thermal processes because it provides insight that cannot be obtained from energy analysis alone. In general the field of exergy analysis is both well formulated and well understood. However, the exergy flux, or the maximum work obtainable, from thermal radiation (TR) heat transfer has not been clearly formulated. Several researchers claim that Petela's thermodynamic approach for determining the maximum work obtainable from radiation is irrelevant to the conversion of fluxes because it appears to neglect a number of fundamental issues—issues that are unusual in the context of exergy analysis. In this paper it is shown that Petela's result gives the exergy flux of blackbody radiation (BR) and represents the upper limit to the conversion of solar radiation (SR) approximated as BR. This conclusion is obtained by resolving a number of fundamental questions including that of: inherent irreversibility, definition of the environment, the effect of inherent emission and the effect of concentrating source radiation. Correctly identifying the exergy flux of TR allows the general exergy balance equation for a control volume to be re-stated so that it correctly applies to TR heat transfer. An ideal (reversible) thermal conversion process for BR fluxes is also presented. Finally, exergetic (second-law) efficiencies are presented for common solar energy conversion processes such as single-cell photovoltaics</p></div>","PeriodicalId":100518,"journal":{"name":"Exergy, An International Journal","volume":"2 1","pages":"Pages 24-33"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1164-0235(01)00040-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73457343","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: 28

Thermodynamics education: Is present coverage of exergy sufficient and appropriate? 热力学教育:目前的火用覆盖是否足够和适当?

Exergy, An International Journal Pub Date : 2002-01-01 DOI: 10.1016/S1164-0235(02)00057-2

Marc A. Rosen

引用次数: 6

Fundamentals of tree-shaped networks of insulated pipes for hot water and exergy 用于热水和火用的树形保温管网的基本原理

Exergy, An International Journal Pub Date : 2002-01-01 DOI: 10.1016/S1164-0235(02)00064-X

Sylvie Lorente , Wishsanuruk Wechsatol , Adrian Bejan

{"title":"Fundamentals of tree-shaped networks of insulated pipes for hot water and exergy","authors":"Sylvie Lorente , Wishsanuruk Wechsatol , Adrian Bejan","doi":"10.1016/S1164-0235(02)00064-X","DOIUrl":"10.1016/S1164-0235(02)00064-X","url":null,"abstract":"<div><p>This paper outlines recent thermodynamic optimization work on the geometric layout of schemes for distributing hot water and exergy over a large system. Constrained are the amount of insulation material, the volume of all the pipes, and the amount of pipe wall material. Unknown are the distribution of insulation over all the links of the network, and the configuration of the network itself. The main focus is on how the geometric configuration may be selected in the pursuit of maximized global performance, and how closely a non-optimal configuration performs to the highest level. Maximum global performance means minimum heat loss to the ambient, minimum pressure loss, and minimum exergy destruction. Three configurations are optimized: </p><ul><li><span>(a)</span><span><p>an area covered by a coiled steam, where all the users are aligned on the same stream,</p></span></li><li><span>(b)</span><span><p>a sequence of tree-shaped flows on square areas in which each area construct is made up of four smaller area constructs, and</p></span></li><li><span>(c)</span><span><p>a sequence of tree-shaped flows where each area construct is made up of two smaller area constructs.</p></span></li></ul> It is shown that the tree-shaped designs (b), (c) outperform significantly the coiled stream design (a). The tree designs obtained by pairing (c) are better than the square tree constructs (b) and, in addition, they deliver water at the same temperature to all the users spread over the territory. The fundamental trade off between minimum heat loss and pressure drop, in the pursuit of minimum exergy destruction, pinpoints the optimal size of each duct and insulation shell.</div>","PeriodicalId":100518,"journal":{"name":"Exergy, An International Journal","volume":"2 4","pages":"Pages 227-236"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1164-0235(02)00064-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82701638","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: 14

Exergy analysis of fluidized bed drying of moist particles 湿润颗粒流化床干燥的火用分析

Exergy, An International Journal Pub Date : 2002-01-01 DOI: 10.1016/S1164-0235(01)00044-9

S. Syahrul , F. Hamdullahpur , I. Dincer

引用次数: 139