Applied sciences

Archives of Thermodynamics

Content

Archives of Thermodynamics | 2015 | No 2 June

Download PDF Download RIS Download Bibtex

Abstract

The paper presents numerical simulation of two-phase flow in a heated capillary with evaporation on the meniscus. To solve the problem, a model of evaporation from meniscus was developed in which the dynamics of liquid-vapour interface is described by the Cahn-Hilliard equation. The numerical simulations were performed using commercial software for 2D axially symmetric case. The flow evolution was analysed for different values of heat transfer coefficient at the capillary wall and inlet liquid mass flow rate.
Go to article

Authors and Affiliations

Jarosław Karwacki
Marcin Lackowski
Helena Nowakowska
Dariusz Butrymowicz
Download PDF Download RIS Download Bibtex

Abstract

The paper presents an analysis of relations describing entropy generation in a condenser of a steam unit. Connections between entropy generation, condenser ratio, and heat exchanger effectiveness, as well as relations implied by them are shown. Theoretical considerations allowed to determine limits of individual parameters which describe the condenser operation. Various relations for average temperature of the cold fluid were compared. All the proposed relations were verified against data obtained using a simulator and actual measurement data from a 200 MW unit condenser. Based on data from a simulator it was examined how the sum of entropy rates, steam condenser effectiveness, terminal temperature difference and condenser ratio vary with the change in the inlet cooling water temperature, mass flow rate of steam and the cooling water mass flow rate.
Go to article

Authors and Affiliations

Rafał Laskowski
Maciej Jaworski
Adam Smyk
Download PDF Download RIS Download Bibtex

Abstract

This paper presents results of investigations on the application of CuO-water nanofluids for intensification of convective heat transfer. Performance of nanofluids with 2.2 and 4.0 vol.% CuO NPs (nanoparticles) content were examined with regard to heat transfer coefficient and pressure losses in case of turbulent flow in a tube. Negligible impact of examined nanofluid on heat transfer improvement was found. Moreover, measured pressure losses significantly exceeded those determined for primary base liquid. The observations showed that application of nanofluid for heat transfer intensification with a relatively high solid load in the examined flow range is rather controversial.
Go to article

Authors and Affiliations

Grzegorz Dzido
Michał Drzazga
Marcin Lemanowicz
Andrzej T. Gierczycki
Download PDF Download RIS Download Bibtex

Abstract

Paper presents the results of experimental and numerical research of a model segment of a labyrinth seal for a different wear level. The analysis covers the extent of leakage and distribution of static pressure in the seal chambers and the planes upstream and downstream of the segment. The measurement data have been compared with the results of numerical calculations obtained using commercial software. Based on the flow conditions occurring in the area subjected to calculations, the size of the mesh defined by parameter y+has been analyzed and the selection of the turbulence model has been described. The numerical calculations were based on the measurable thermodynamic parameters in the seal segments of steam turbines. The work contains a comparison of the mass flow and distribution of static pressure in the seal chambers obtained during the measurement and calculated numerically in a model segment of the seal of different level of wear.
Go to article

Authors and Affiliations

Damian Joachimiak
Piotr Krzyślak
Download PDF Download RIS Download Bibtex

Abstract

In this paper, the thermodynamic investigation on the use of geothermal water (130°C as maximum) for power generation through a basic Rankine has been presented together with obtained main results. Six typical organic working fluids (i.e., R245fa, R141b, R290, R600, R152a, and 134a) were studied with modifying the input pressure and temperature to the turbine. The results show that there are no significant changes taking place in the efficiency for these working fluids with overheating the inlet fluid to the turbine, i.e., efficiency is a weak function of temperature. However, with the increasing of pressure ratio in the turbine, the efficiency rises more sharply. The technical viability is shown of implementing this type of process for recovering low temperature heat resource.
Go to article

Authors and Affiliations

Yan-Na Liu
Song Xiao
Download PDF Download RIS Download Bibtex

Abstract

The paper presents a literature review on the topic of vapour power plants working according to the two-phase thermodynamic cycle with supercritical parameters. The main attention was focused on a review of articles and papers on the vapour power plants working using organic circulation fluids powered with low- and medium-temperature heat sources. Power plants with water-steam cycle supplied with a high-temperature sources have also been shown, however, it has been done mainly to show fundamental differences in the efficiency of the power plant and applications of organic and water-steam cycles. Based on a review of available literature references a comparative analysis of the parameters generated by power plants was conducted, depending on the working fluid used, the type and parameters of the heat source, with particular attention to the needs of power plant internal load.
Go to article

Authors and Affiliations

Szymon Mocarski
Aleksandra Borsukiewicz-Gozdur

Instructions for authors

Archives of Thermodynamics publishes original papers which have not previously appeared in other journals. The journal does not have article processing charges (APCs) nor article submission charges. The language of the papers is English. The paper should not exceed the length of 25 pages. All pages should be numbered. The plan and form of the papers should be as follows:

1. The heading should specify the title (as short as possible), author, his/her complete affiliation, town, zip code, country and e-mail. Please indicate the corresponding author. The heading should be followed by Abstract of maximum 15 typewritten lines and Keywords.

2. More important symbols used in the paper can be listed in Nomenclature, placed below Abstract and arranged in a column, e.g.:
u – velocity, m/s
v – specific volume, m/kg etc.
The list should begin with Latin symbols in alphabetical order followed by Greek symbols also in alphabetical order and with a separate heading. Subscripts and superscripts should follow Greek symbols and should be identified with separate headings. Physical quantities should be expressed in SI units ( Système International d’Unités).

3. All abbreviations should be spelled out first time they are introduced in the text.

4. The equations should be each in a separate line. Standard mathematical notation should be used. All symbols used in equations must be clearly defined. The numbers of equations should run consecutively, irrespective of the division of the paper into sections. The numbers should be given in round brackets on the righthand side of the page.

5. Particular attention should be paid to the differentiation between capital and small letters. If there is a risk of confusion, the symbols should be explained (for example small c) in the margins. Indices of more than one level (such as Bfa) should be avoided wherever possible.

6. Computer-generated figures should be produced using bold lines and characters. No remarks should be written directly on the figures, except numerals or letter symbols only. Figures should be as small as possible while displaying clearly all the information requires, and with all lettering readable. The relevant explanations can be given in the caption.

7. The figures, including photographs, diagrams, etc., should be numbered with Arabic numerals in the same order in which they appear in the text. Each figure should have its own caption explaining the content without reference to the text.

8. Computer files on an enclosed disc or sent by e-mail to the Editorial Office are welcome. The manuscript should be written as a MS Word file – ∗.doc, ∗.docx or LATEX file – ∗.tex. For revised manuscripts after peer review process, figures should be submitted as separate graphic files in either vector formats (PostScript (PS), Encapsulated PostScript (EPS), preferable, CorelDraw (CDR), etc.) or bitmap formats (Tagged Image File Format (TIFF), Joint Photographic Experts Group (JPEG), etc.), with the resolution not lower than 300 dpi, preferably 600 dpi. These resolutions refer to images sized at dimensions comparable to those of figures in the print journal. Therefore, electronic figures should be sized to fit on single printed page and can have maximum 120 mm x 170 mm. Figures created in MS World, Exel, or PowerPoint will not be accepted. The quality of images downloaded from websites and the Internet are also not acceptable, because of their low resolution (usually only 72 dpi), inadequate for print reproduction.

9. The references for the paper should be numbered in the order in which they are called in the text. Calling the references is by giving the appropriate numbers in square brackets. The references should be listed with the following information provided: the author’s surname and the initials of his/her names, the complete title of the work (in English translation) and, in addition:

(a) for books: the publishing house and the place and year of publication, for example:
[1] Holman J.P.: Heat Transfer. McGraw-Hill, New York 1968.

(b) for journals: the name of the journal, volume (Arabic numerals in bold), year of publication (in round brackets), number and, if appropriate, numbers of relevant pages, for example:
[2] Rizzo F.I., Shippy D.I.: A method of solution for certain problems of transient heat conduction . AIAA J. 8(1970), No. 11, 2004–2009.

For works originally published in a language other than English, the language should be indicated in parentheses at the end of the reference.

Authors are responsible for ensuring that the information in each reference is complete and accurate.

10. As the papers are published in English, the authors who are not native speakers of English are obliged to have the paper thoroughly reviewed language-wise before submitting for publication.


Manuscript submission

Manuscripts to be considered for publication should be electronically submitted to the Editorial Office via the online submission and reviewing system, the Editorial System, at http://www.editorialsystem.com/aot. Submission to the journal proceeds totally on line and you will be guided stepwise throughout the process of the creation and uploading of your files. The body of the text, tables and figures, along with captions for figures and tables should be submitted separately. The system automatically converts source files to a single PDF file article, for subsequent approval by the corresponding Author, which is then used in the peer-review process. All correspondence, including notification confirming the submission of the manuscripts to the Editorial Office, notification of the Editorsñs decision and requests for revision, takes place by e-mails. Authors should designate the corresponding author, whose responsibility is to represent the Authors in contacts with the Editorial Office. Authors are requested not to submit the manuscripts by post or e-mail.
The illustrations may be submitted in color, however they will be printed in black and white in the journal, so the grayscale contributions are preferable. Therefore, the figure caption and the entire text of the paper should not make any reference to color in the illustration. Moreover the illustration should effectively convey author’s intended meaning when it is printed as a halftone. The illustrations will be reproduced in color in the online publication.


Further information

All manuscripts will undergo some editorial modification. The paper proofs (as PDF file) will be sent by e-mail to the corresponding author for acceptance, and should be returned within two weeks of receipt. Within the proofs corrections of minor and typographical errors in: author names, affiliations, articles titles, abstracts and keywords, formulas, symbols, grammatical error, details in figures, etc., are only allowed, as well as necessary small additions. The changes within the text will be accepted in case of serious errors, for example with regard to scientific accuracy, or if authors reputation and that of the journal would be affected. Submitted material will not be returned to the author, unless specifically requested. A PDF file of published paper will be supplied free of charge to the Corresponding Author. Submission of the manuscript expresses at the same time the authors consent to its publishing in both printed and electronic versions.


Transfer of Copyright Agreement

Submission of the manuscript means that the authors automatically agree to assign the copyright to the Publisher. Once a paper has been accepted for publication, as a condition of publication, the authors are asked to send by email a scanned copy of the signed original of the Transfer of Copyright Agreement, signed by the Corresponding Author on behalf of all authors to the Managing Editor of the Journal. The copyright form can be downloaded from the journal’s website at http://www.imp.gda.pl/archives-of-thermodynamics/ under Notes for Contributors.

This page uses 'cookies'. Learn more