Cross-Scale Simulation for Air-side Thermo-Fluid Performance of Direct Air-Cooling Condenser

doi:10.3969/j.issn.1000-7229.2015.08.003

Abstract

Abstract:

For the antifreezing industrial demand of direct air-cooling condenser in winter, the model on finned tube scale was coupled with that on air-cooling unit scale, both the whole heat transfer characteristics in finned tube bundle and the impingement heat transfer characteristic of condensate water in air-cooling finned tube were studied, which could provide the third thermal boundary condition for the calculation of the in-tube condensation heat transfer and freezing in direct air-cooling condenser under the condition of low temperature operation in winter. The air-cooling condenser cell model and finned tube model were constructed. Then, the simulation results of finned tube under 3D inlet wind velocity boundary condition was simplified as input-output type agent model. The velocity distribution at the windward surface and symmetric boundary was obtained from air-cooling condenser cell numerical simulation. Then the finned tube agent model was applied in the symmetric boundary to obtain the spatial distribution of the impingement heat transfer characteristics and average convective heat transfer characteristics of finned tube at symmetric boundary. The numerical calculation results show that, the impinging heat transfer coefficient has a larger magnitude than the average convective heat transfer coefficient； at the windward surface, the distributions of those two coefficients are both up-down asymmetrical and left-right asymmetrical； and the impinging heat transfer coefficient decreases with the decrease of the rotational speed.

Key words: direct air-cooling condenser, cross-scale simulation, heat transfer, freezing

CLC Number:

CHENG Tongrui, DU Xiaoze, YANG Lijun. Cross-Scale Simulation for Air-side Thermo-Fluid Performance of Direct Air-Cooling Condenser[J]. ELECTRIC POWER CONSTRUCTION, 2015, 36(8): 15-21.

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