Publication detail

Evaluation of the Effect of Tube Pitch and Surface Alterations on Temperature Field at Sprinkled Tube Bundle

KRACÍK, P. COPEK, T. ZACHAR, M. POSPÍŠIL, J.

Original Title

Evaluation of the Effect of Tube Pitch and Surface Alterations on Temperature Field at Sprinkled Tube Bundle

Type

conference paper

Language

English

Original Abstract

Water flowing on a sprinkled tube bundle forms three basic modes: It is the Droplet mode (liquid drips from one tube to another), the Jet mode (with an increasing flow rate droplets merge into a column) and the Membrane (Sheet) mode (with further increasing of falling film liquid flow rate columns merge and create sheets between the tubes. With sufficient flow rate sheets merge at this state and the tube bundle is completely covered by a thin liquid film). There are several factors influencing the individual mode types as well as heat transfer. Beside the above mentioned falling film liquid flow rate they are for instance tube diameters, tube pitches in a tube bundle or a physical condition of a falling film liquid. This paper presents a summary of data measured at atmospheric pressure at a tube bundle consisting of copper tubes of 12 milimeters diameter and of the studied tube length one meter. The tubes are positioned horizontally one above another with the tested pitches of 15, 20, 25 and 30 mm and there is a distribution tube placed above them with water flowing out. The thermal gradient of 15–40 has been tested with all pitches where the falling film liquid's temperature at the inlet of the distribution tube was 15 deg.C. The liquid was heated during the flow through the exchanger and the temperature of the sprinkled (heater) liquid at the inlet of the exchanger with a constant flow rate about 7.2 litres per minute was 40 deg.C. The tested flow of the falling film liquid ranged from 1.0 to 13.0 litres per minute. Sequences of 180 exposures have been recorded in partial flow rate stages by thermographic camera with record frequency of 30 Hz which were consequently assessed using the Matlab programme. This paper presents results achieved at the above mentioned pitches and at three types of tube bundle surfaces.

Keywords

temperature field, sprinkled, thermovision measurements

Authors

KRACÍK, P.; COPEK, T.; ZACHAR, M.; POSPÍŠIL, J.

RIV year

2015

Released

6. 5. 2015

Publisher

EDP Sciences

Location

Francie

ISBN

2100-014X

Periodical

EPJ Web of Conferences

Year of study

92

Number

2015

State

French Republic

Pages from

1

Pages to

8

Pages count

8

Full text in the Digital Library

http://hdl.handle.net/11012/196355

BibTex

@inproceedings{BUT110702,
  author="Petr {Kracík} and Tomáš {Copek} and Martin {Zachar} and Jiří {Pospíšil}",
  title="Evaluation of the Effect of Tube Pitch and Surface Alterations on Temperature Field at Sprinkled Tube Bundle",
  booktitle="EPJ Web of Conferences",
  year="2015",
  journal="EPJ Web of Conferences",
  volume="92",
  number="2015",
  pages="1--8",
  publisher="EDP Sciences",
  address="Francie",
  doi="10.1051/epjconf/20159202039",
  issn="2100-014X"
}