Calculation of radiation heat transfer in staggered drop-shaped tubes bundle

Abstract

Tube bundles can be used as a separation heat exchanger in the “organic” Rankine cycle power plants (ORC), while the hot gas passes over the outer surface, and the working substance in ORC flows inside the tubes. Numerical study of the hydrodynamics and heat transfer of a staggered bundle of drop-shaped tubes at different angle of attack (θ) of the incoming gas flow is carried out using the ANSYS package. The distribution of velocity, pressure, temperature in the studied bundle are obtained and the relation for calculating the average Nusselt number for the stress-strain state of the tubes bundle is proposed. The numerical method of calculation of the elementary, local and average radiation view factors for staggered bundle of drop-shaped tubes is developed using the “crossed-strings method”. The radiation net fluxes in the systems of drop-shaped and circular tubes with the same equivalent diameter are determined.