Search

The multi-objective territorial particle swarm optimization (MOTPSO) technique is proposed in this work for the optimal design of steam suiface condensers. The main objective of this work is to maximize the condensation rate in a condenser while the pressure loss is minimized. Various design parameters, such as the tube outside diameter, thickness, and pitch, are considered to find the optima! ones for shell and tube heat exchangers considered in this study. The two-dimensional computational fluid dynamics (CFD) analysis is pei formed to solve the fluid flow and heat transfer in the condenser to assess the performance of different designs. [ABSTRACT FROM AUTHOR]

In this paper, various turbulence models are compared to determine which models are most accurate in simulating two-phase fluid flow and heat transfer in steam surface condensers. The numerical method is based on the conservation equations of mass and momentum for both gas-phase and liquid-phase, and mass fraction conservation equation for non-condensable gases. Modified standard k – ε and RNG k – ε models are proposed to account for the effects of tube bundles and two-phase interactions on the gas-phase turbulence. A quasi-three-dimensional approach is used to account for the effect of the temperature difference in the coolant flowing in the tubes. Finally, the numerical results are compared with the experimental data to assess the performance of the proposed turbulence models. [ABSTRACT FROM AUTHOR]

In this study, a three-dimensional numerical model has been developed to simulate the fluid flow and heat transfer in industrial steam surface condensers with complex irregular shapes. The numerical method is based on the Eulerian–Eulerian two-phase model by solving the conservation equations of mass and momentum for both gas-phase and liquid-phase, and the mass fraction conservation equation for the non-condensable gases. A distributed resistance formulation (porous media) approach is used to account for the effect due to the presence of tubes on the shell-side flow in the condenser. Also, the convective heat transfer correlations are used to model the heat and mass transfer between the shell-side fluid and the tube-side fluid. The effect of the turbulence and non-condensable gases on the primary phase flow is also included in the numerical model. The numerical results are compared with the experimental data for a small experimental condenser and a full-size industrial condenser, and the proposed numerical model is proved to be relatively accurate in simulating the turbulent two-phase flows in condensers. Finally, the comparison is made between the current three-dimensional model and the quasi-three-dimensional model proposed in the previous work. [ABSTRACT FROM AUTHOR]