Technology Development of Large-scale Heat Exchanger in China

Abstract

Large-scale shell-and-tube heat exchanger(STHE),spiral wound heat exchanger(SWHE) and plate-shell heat exchanger(PSHE) have been widely used in many industries.The technical difficulties of these heat exchangers suitable for large-scale ethylene,refinery and coal-chemical plant are discussed.During the 11th five plan period,remarkable developments were made in such aspects as the cooperativity study between the structure and process design of heat transfer fluid flow,the material technical requirements of super-long heat exchange tube,and the design and manufacturing technology of large tube-sheet for large-scale STHE.Such large-scale SWHE products as the large-scale multi-stream SWHE,the high pressure SWHE using Ni-base alloy butt welded joints with low residual stress,and the feed gas cooler of rectisol unit with combinative structure are successfully developed one after another.The domestic manufacturing of super-large PSHE is guaranteed by such key technologies as the heat exchange plate considering both fluid distribution and heat transfer performance,the stepping compression molding process for whole plate,the argon shielded arc welding or resistance welding process,and the new type of feed spray distributor etc.The representative products of large-scale heat exchangers are also listed.The heat exchange areas are larger than 10 000 m2 for STHE,7 000 m2 for SWHE and 10 000 m2 for PSHE in China.All these above mentioned products have been successfully put into service in the coal-chemical and petro-chemical plants.With focus on such aspects as the actual phase transformation mechanism study for mixed medium,the adoption of highly effective heat transfer element and the reliability study of large-scale heat exchanger etc.,several questions related to the domestic manufacturing of these large-scale heat exchangers and their future developing direction are presented.