Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

HYDRODYNAMICS AND HEAT AND MASS TRANSFER DURING IMPACT IRRIGATION BY A SYSTEM OF JETS OF A VERTICAL SURFACE OF A HEAT EXCHANGER

Get access (open in a dialog) DOI: 10.1615/IHTC16.mpf.023903
pages 6837-6843

Abstrakt

In this paper, the performance of a water spray cooling system is investigated experimentally. To study the cooling of large heating surfaces, a controlled multi-nozzle source, placed in a heat exchanger-spray system, was developed. Water was used as the working fluid in the experiments. The influence of the main parameters of the pulsed two-phase spray is shown: the contribution to the heat transfer of the speed of the sluggish gas flow, the evolution of the drip flow in the drift zone (grouping, coalescence), the influence of the specific flow rate of the gas and air flow. The data showed that with the selected irrigation regimes, two successive cooling regimes are realized on the surface under investigation: film and evaporative. With an increase in the specific flow rate of the liquid, the film is evenly distributed throughout the surface of the heat exchanger. It is shown that the intensification of heat transfer is due to the contribution of evaporative cooling of the formed film, wetting of dry sections of the surface of the heat exchanger with primary and secondary drops in the intervals between pulses. An increase in the frequency of repetitions at a constant duration of the pulses of the liquid phase in the gas-droplet flow leads to the fact that the contribution of the evaporation process decreases, and in heat exchange the main mechanism is the transfer of thermal energy to the liquid film.