Abstract: New combined plate heat exchangers and four kinds of new distribution regions of plate heat exchanger have been established by SOLIDWORKS software, and simulated by FLUENT software based on Computational Fluid Dynamics method. Heat transfer coefficient and pressure drop of new combined plate heat exchangers have been analyzed, according to which the optimal parameters have been chosen. The normal distribution area has been analyzed according to its flow pattern, pressure drop and distribution performance. Four kinds of new distribution area have been proposed based on the analysis. The results show that new combined plate heat exchanger J plate could maintain the performance in terms of heat exchange and the pressure drop decrease compared with normal M plate. While the corrugation angle of big corrugation angle plate (plate ②) of combined plate is 60 degrees and the corrugation intercept is 18mm or 16mm or 14mm, the convection heat transfer coefficient and the pressure drop increase with the increasing of the corrugation angle of small corrugation angle plate (plate ①) whether for hot or cold fluid. While the corrugation angle of plate ① is 30 or 40 degrees, the corrugation intercept of plate ② has little influence on combination performance. While the corrugation angle of plate ① is 50 degrees, the corrugation intercept of plate ② has great influence on combination performance. Distribution region strongly influences the distribution of working fluid in plate heat exchangers. Normal distribution region has poor distribution performance along with large pressure drop. The distribution region of M series has better distribution performance and smaller pressure drop. New-designed distribution regions present better distribution performance and smaller pressure drop, as well. Among them, distribution region Ⅲ shows the best distribution performance and less pressure drop.

Key words: distribution area, flow, numerical simulation, plate heat exchanger (PHE), pressure drop