加氢裂化尾油沉浸式水槽热交换器传热特性及计算

Heat Transfer Characteristics and Calculation of Heat Exchanger in Hydrocracking Tail Oil Submerged Water Tank

结合中试装置加氢裂化尾油(HTO)沉浸式水槽热交换器的现场运行数据,分析了在不同冷却水用量条件下HTO沉浸式水槽热交换器的传热规律,对比了在夏季工况和冬季工况条件下热交换器的热损失、蒸发量及传热效果,提出了在同类型热交换器设计中以夏季工况作为设计工况,冬季工况作为校核工况的可行性。在实际运行中,采取向水槽内冷却水底部鼓泡措施来提高传热系数,取得了良好的效果。在一定气速下,鼓泡口个数对传热系数有显著影响。通过对比实际运行参数与设计计算值,明确了此类热交换器传热系数计算时宜选用的经验关联式,可为同类型热交换器设计计算提供参考。在保守计算时,也可选取总传热系数的经验值31.1～32.4 W/(m^2·℃)进行简捷计算。

Based on the operational parameters of hydrocracking tail oil(HTO) submerged water tank heat exchanger in a pilot-plant, the heat transfer characteristics of HTO submerged water tank heat exchanger with different flow rate of water supply was analyzed. The heat loss, evaporation and heat duty of HTO submerged water tank heat exchanger in summer and winter were summarized based on the different season services. It shows that the feasibility of the selection of summer service as the design mode and the winter service as checking mode. Bubbling from tank bottom in actual operation improves the heat transfer coefficient and heat transfer performance of HTO submerged water tank heat exchanger. The number of bubbling ports has a significant influence on the heat transfer coefficient. The comparisons between actual measured value and theoretical calculated value were carried out to ensure the best-estimate fit correlation. The overall heat-transfer coefficient as 31.1~32.4 W/(m^2·℃) could be selected during the conservative calculation of this type submerged water tank heat exchangers.