煤化工大型缠绕管式换热器的设计与制造

Design and Manufacturing of Large-scale Spiral Wound Heat Exchanger in Coal-chemical Industry

大型缠绕管式换热器不仅具有较好的传热性能,还同时具有对装置变负荷的适应性和运行可靠的操作特性,在我国煤炭深加工、炼油、天然气等领域的应用呈现出良好的发展前景。从煤化工大型多股流缠绕管式换热器出发,对缠绕管式换热器设计和制造的技术难点进行分析。在多股流缠绕管式换热器方面,论述了管板的不同结构形式、管板设计计算的特殊性、各管程在同一壳体内的协调性、组合式大型原料气冷却器等内容;同时对管束与管板之间的引出结构进行了讨论;结合奥氏体不锈钢材料的应变时效分析结果,给出了缠绕过程换热管正常变形率的范围;对大型缠绕管式换热器管子与管板焊接接头的射线检测,给出了可以参考的操作准则。我国已能生产换热面积超过10000 m2的大型缠绕管式换热器,在设计和制造方面积累了很多的经验,但是在缠绕管式换热器材料的多样性、大型主低温换热器的工艺设计、数值模拟技术在设计上的应用以及换热管与管板连接质量检测的量化技术等方面,我国和欧美先进国家还有一定的差距。

Due to its excellent heat transfer property,the adaptability to variable loads of unit and the op-eration reliability,large-scale spiral wound heat exchanger （SWHE）has a bright application prospect in such fields as the coal deep processing,refinery and natural gas of China.With respect to the multi-stream SWHE for large-scale coal-chemical plant,the design and manufacturing technology difficulties are ana-lyzed for large-scale SWHE.As to the multi-stream SWHE,such contents as the different structure styles of tube-sheet,particularity of tube-sheet design calculation,compatibility of each tube side in the same shell and the large-scale combined raw gas cooler are discussed.Additionally,the outlet structure between tube bundle and tube -sheet is also discussed .Combined with the analysis results of strain aging for austenitic stainless steel,the normal deformation rate range is obtained for the heat exchanger tube during wrapping. Radiographic testing （RT）is carried out for the weldment between tubes and tube-sheet of large-scale SWHE,and the RT operation rule is presented for reference.In China,the large-scale SWHE with area larger than 10000 m2 can be produced now,and abundant experience has been accumulated in the design and manufacturing technology.However,there is still a certain gap between our country and the advanced countries in Europe and America in such aspects as the material variety of SWHE,the process design of large-scale main cryogenic heat exchanger,the application of numerical simulation technology in design and the quantified technology of quality inspection for the weldment between heat exchanger tube and tube-sheet etc.