Studying boiling on a sphere surface by gradient heat-metering method

Аuthors

Sapozhnikov S. Z.¹, Mityakov V. Y.^1*, Mityakov A. V.¹, Gusakov A. A.^2**, Pavlov A. V.^1***, Bobylev P. G.^1****

1. Peter the Great St. Petersburg Polytechnic University, 29, Polytechnicheskaya str., St. Petersburg, 195251, Russia
2. Peter the Great Saint-Petersburg Polytechnic University, 29, Polytechnicheskaya str., St. Petersburg, 195251, Russia

*e-mail: mitvlad@mail.ru
**e-mail: a.gusakov.spb@mail.ru
***e-mail: pavlovAV196@mail.ru
****e-mail: pavel_b.g.97@mail.ru

Abstract

The article provides a study of the saturated and subcooled water boiling on the ball surface. The combined method of gradient heat-metering and high-speed visualization became the main research method. The combined technique allowed:

• Determining the boundaries of the boiling modes such as film, transient and nucleate boiling;
• Compare the process hydrodynamics with the values of the heat flux per unit area.

The article presents a brief overview of the operation principle of the heat flow sensor and provides the experimental setup description. Experiments in saturated water demonstrated complete agreement with the results of Shiro Nukiyama. The second critical heat flux values obtained in our experiments hit the range of values obtained by a Japanese researcher under the same initial conditions. A significant difference in the intensity of the processes at the north and south poles of the model was obtained. Heat flux graph constructed for a water temperature of 25 and 50 centigrade and the model initial temperature of 350 and 450 centigrade revealed that the heat removal level was being determined by the liquid underheating, rather than the temperature head. A comparison with literature sources revealed a partial matching of the results due to the new research method implementation. In contrast to thermometry, the gradient heat-metering, allows directly fixing the heat flux per unit area. This method has proven itself as a reliable method for studying phase transitions and non-stationary processes.

Keywords:

gradient heat-metering, heterogeneous gradient heat flow sensors, heat flow local density, bubble boiling mode, circular thermograms

References

1. Saburo T., Michitsugu M. Subcooled film boiling and the behavior of vapor film on a horizontal wire and a sphere. Proceedings of the 7th International Heat Transfer Conference, Munich, 1982, pp. 173–178.
2. Zabirov A.R. Issledovanie protsessov teploobmena pri okhlazhdenii vysokotemperaturnykh tel v nedogretykh zhidkostyakh, (Investigation of heat transfer processes during cooling of high-temperature bodies in underheated liquids), Dissertation of the Candidate of Technical Sciences. Moscow, MEI, 2016. 200 p.
3. Yagov V.V., Zabirov A.R., Leksin M.A. Nestatsionarnyi teploobmen pri plenochnom kipenii nedogretoi zhidkosti. Teploenergetika, 2015, no. 11, pp. 70–80.
4. Sapozhnikov S.Z., Mityakov V.Yu., Mityakov A.V. The Study of Heat Flux Measurement for Heat Transfer during Condensation at Pipe Surfaces. Tech. Phys. Lett, 2019, vol. 45, pp. 321–323.
5. Sapozhnikov S.Z., Mityakov V.Yu., Mityakov A.V. Heatmetry The Science and Practice of Heat Flux Measurement. Springer International Publishing, St.-Petersburg, 2020. 209 p.
6. Mityakov V.Yu., Pavlov A.V., Bobylev P.G. Nedelya Nauki SPbPU 2019: 29-aya Vseros. Konf., Sozdanie i graduirovka pervichnykh preobrazovatelei na osnove kompozitsii med’-nikel’ , SPbPU, 2019, 2019, pp. 164–166.
7. Labuntsov D.A., Gomelauri A.V. Telpoobmen pri plenochnom kipenii kriogennykh i obychnykh zhidkostei na vertikal’nykh poverkhnostyakh. Moscow, Trudy MEI, 1976, pp. 41‒50.
8. Bromley L.A. Heat Transfer in Stable Film Boiling. Berkeley, California, 1949.
9. Sapozhnikov S.Z., Mityakov V.Yu., Mityakov A.V., Subbotina V.V. Eksperimental’noe issledovanie plenochnogo kipeniya nedogretoi vody metodom gradientnoi teplometrii // Pis’ma v ZhTF, 2019, vol. 45, no. 6.
10. Kutateladze S.S. Osnovy teorii teploobmena (Fundamentals of the theory of heat transfer), 5th ed, Moscow, Atomizdat, 1979. 416 p.
11. Nukiyama S. The maximum and minimum values of the heat Q transmitted from metal to boiling water under atmosphere pressure. Int. J. Heat Mass Transfer, 1934, vol. 27, no. 7, pp. 959–970.