碳化硅－金属组合式高温换热器的研制

Development of high-temperature heat exchangers of sillcon carbide and matallic units

本文针对小型工业炉高温烟气余热回收，提出一种新型碳化硅－金属组合式高温换热器。其中高温段的ＳｉＣ装置采用了新开发研制的内翅片式ＳｉＣ换热管、改进的密封和热补偿结构，使传热效率和结构紧凑性得以提高；中温段金属换热器以Ｕ形管结构消除温差应力，并从结构和流程上防止了管板和管壁超温过热。该组合换热器工业试验装置用于锻造加热炉热能回收，在８００－９２０℃的烟温下，将空气预热到１００－１５３℃，操作性能稳定，取得良好节能效果。

new type of high-temperature heat exchangers of silicon carbide and metallic units were proposed for recov-ery of high temperature flue gas in small -sized industrial surnaces. The heat transfer efficiency and structure com-pactness were improved by using newly-developed internalfinned SiC heat exchanger tubes ,improved seals ,and heat compensating structure for SiC plants at high temperaturesection.The temperature difference stress was eliminatedby metal heat exchangers with U-shaped tube structure atmiddle temperature section ,and ultra -temperature and su-perheat were avoided in structure and flow,The industrial pilot plants of combined heat exchangers were used for heatrecovery of forging furnaces . The operating performance of the heat exchangers was stable when air was heated to 400- 453℃ by flue gas at 800- 920℃,and a good energy-saving result was obtained.