| dc.description.abstract | In the recent years, most of investigations of two phase flow distribution in plate heat exchanger (PHE) were experimental study. Due to complexity of flow and thermal structure inside PHE, researchers used simpler flat/circular tubes to represent the real plate in PHE. This study used the Computational fluid dynamics software ANSYS FLUENT to model an industrial type of K050 chevron corrugation PHE and simulated the two phase flow distribution. Several effects were studied, including two phase flow, flow maldistribution, the operating condition and the direction of the inflow distributor.
This paper was divided into two parts. First, the air/water two phase flow was investigated for effect of various direction of air inflow distributor (12 clock, 3 clock, 4 clock, 5 clock, 6 clock and 9 clock) in the single channel PHE. Simulation results showed that the direction of 3, 4 and 6 clocks generated better flow distribution. At low Reynolds number (Rel =500), the case of 3 clock had the most uneven flow distribution, while better flow distribution was observed for the case of 6 clock. At medium Reynolds number (Rel =1500), all the three cases (3, 4, 6 clocks) improved their flow distribution with reduced standard deviation of flowrate. It can be concluded that the increase of the Reynolds number which transformed the flow into turbulent and improved the flow distribution across channels inside PHE. At the high Reynolds number (Rel =3000), the case of 4 clock had the best even flow distribution. Finally, consider the effects of the flow passages on the hot/cold sides and the pressure drop, air inflow at 4 clock of the distributor was recommended.
The second part was investigation for the improvement of two phase flow distribution in a 10-channel PHE with an inflow distributor. Numerical results showed that at the multi-channels PHE without the distributor, the flow must operated at higher Reynolds number in order to have better flow distribution. If the PHE operated under Reynolds number lower than 1500, the vapor-liquid distribution can very uneven.
With the inflow distributor added, the maldistribution of the vapor phase improved significantly. Yet the flow distribution of liquid phase only worked at low Reynolds number condition. As Reynolds number increased, the inflow distributor was not that effective for liquid flow distribution.
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