INFLUENCE MOISTURE FORMATION ON CYLINDER SURFACE ON THE DETERMINATION OF HEAT TRANSFER COEFFICIENT AIR DURING APPLICATION OF THE METHOD OF MELTING ICE
Circular cylinders with cross-flow are a component of many technical devices in power engineering, heat engineering and chemical technology.
For the intensification of external heat exchange, various types of ribs are widely used, the use of which is associated with a large metal capacity of the equipment. Application of holes on the heat exchange surface can significantly improve the thermohydraulic and mass-grossing characteristics of heat and mass equipment. A simple and effective way of intensifying heat transfer is the spiral groove on the outer surface of the pipe.
The purpose of this work is to develop a method for determining the average coefficient of heat transfer by the method of melting ice, taking into account the moisture that falls on the surface of the cylinder-calorimeter. The research was carried out in the range of the Reynolds number change, calculated from the outside diameter of the pipe, from 2000 to 17000.
In this paper, the method of determining the average coefficient of heat transfer by the method of melting of ice at the cross-flow of a round cylinder is specified. It is shown that ignoring the air humidity flowing through the cylinder-calorimeter can lead to a large error in determining the average coefficient of heat transfer, especially when air humidity is more than 53%.
2. Written EI. N. Heat transfer and aerodynamics of packages of cross-sectioned pipes. Kiev: AlterPress 2004
3. Yudin V.F. Heat transfer of transverse finned tubes. Leningrad: Mechanical Engineering, 1982.
4. Kovalenko G.V. Circulation of cylinders with gas flow during turbulization of the boundary layer. Scientific review. 2014 number 8. S. 548 - 553.
5. Kovalenko G. V., Meires A. Zh. Comparison of different methods of intensification of heat exchange on cylindrical surfaces. East European Magazine of Advanced Technology. 2013 3/12 (63), pp. 58 - 60.
6. Schlichting G. Theory of the boundary layer. Moscow: Science, 1969.
7. Kovalenko G.V., Khalatov A. A. Application of ice calorimeters for investigation of heat transfer of surfaces formed by recesses. Industrial heat engineering. 2008. № 2. S. 5-12.
8. Taubman E.I., Goryev V. A., Melzer V. L., Pastushenko B. L., Savinkin V. I. Contact Heat Exchangers M., Chemistry, 1987. 256 p.
9. Zaidel A. N. Elemental estimations of errors of study measurements. Manual for a student. higher studying Head L .: Nauka, Leningrad Branch 1967. 88 p.
10. Isachenko V. P., Osipova V. A, Sukomel A. S. Heat transfer. M .: Energoizdat, 1981. 416 p.
Abstract views: 73 PDF Downloads: 45
If the article is accepted for publication in the journal «Industrial Heat Engineering» the author must sign an agreementon transfer of copyright. The agreement is sent to the postal (original) or e-mail address (scanned copy) of the journal editions.
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License International CC-BY that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.