Simulation on the distribution of heat transfer parameters in a horizontal tube falling film evaporator

Based on the distributed parameter model (DPM), a three-dimensional simulation is conducted on a single horizontal tube falling film evaporator applied in the low temperature multi-effect distillation system. The variation law of the of heat transfer parameters within the evaporator under different brine inlet salinities and spray densities are analyzed. The results show that the averaged heat transfer coefficient of the evaporator increases with the increment of brine inlet spray density and the decrement of brine inlet salinity. On the premise that the steam condenses completely at the end of the second tube pass, the superficial temperature difference of the evaporator decreases with the increment of brine inlet spray density and the decrement of brine inlet salinity. The maximum intertube vapor temperature drop decreases with the increment of brine inlet spray density and the decrement of brine inlet salinity. The distribution law of heat transfer rate as well as heat transfer coefficient varies as the variation of brine inlet spray density. © 2014, Science Press. All right reserved.