Experimental investigation on heat transfer characteristics of two-phase propane flow condensation in shell side of helically baffled shell-and-tube condenser

For designing helically baffled shell-and-tube heat exchangers (HBHXs) used liquefied natural gas (LNG) process, the condensation heat transfer mechanism in the shell side of HBHXs should be known. In the present study, the condensation heat transfer characteristics and flow patterns of propane spirally flowing in shell side of horizontal HBHXs were experimentally investigated. Experimental conditions cover mass flux of 20-40 kg (m2 s)−1, heat flux of 3.0-7.0 kW m−2, and vapor quality from 0.1 to superheated. The results show that, the heat transfer coefficient decreases with the increase of heat flux, and it initially increases and then decreases with the increase of vapor quality. As the vapor quality increases, the stratified flow, stratified-spray flow and spray flow were observed in sequence. A correlation was developed to predict the heat transfer coefficient, and it can agree with 86% of experimental data within a deviation of ±10%.