The effect of plate corrugation on the wetting performance of plate heat exchanger for desalination

Latest market trends in seawater desalination show a marked shift towards the multiple effect distillation (MED) process. This is mainly due to the advantages the MED process has over the multi-stage flashing (MSF) process, such as lower energy consumption and higher water recovery ratio. The MED process is expected to gain bigger shares in thermal-based desalination installations in the coming years; and with more technological advancements, the unit cost of MED-product water is expected to become competitive and more attractive in comparison with today’s relatively low-cost and viable reverse osmosis (RO) desalination technology. The MED process can be divided into two categories depending on the type of heat exchanger technology employed, that is, shell and tube heat exchangers (STHE) and plate heat exchangers (PHE). The falling film horizontal tube heat exchanger is the most widely used configuration of the STHE technology employed in MED seawater desalination today. However, a new trend is emerging where the PHE technology is establishing presence in the MED desalination applications. PHE technology has significant advantages due to its supe-rior heat transfer performance and the ability to pack fairly large heat transfer surface area in the most compact volume. Employing PHE technology in the MED process is considered a major step in the intensification process of MED for seawater desalination, which has been one of the major focus areas of research under the strategic plan of the Water Research Center (WRC) at the Kuwait Institute for Scientific Research (KISR). The study was unique since there is information gap on PHE technology in the MED desalination applications. This hydrodynamic parametric study was performed at atmospheric pressure and ambient temperature, and was used to obtain the optimum and safe surface wetting. For fixed nozzle type and clearance, three plate cassettes of different corrugations were tested with four different flowrates and four different temperatures.