开架式气化器换热管束损伤机理及最优更换周期分析

ANALYSIS OF DAMAGE MECHANISM AND OPTIMAL REPLACEMENT CYCLE OF ORV HEAT EXCHANGE TUBE BUNDLE

换热管束是开架式气化器(ORV)设备的关键部件。换热管束内的LNG和外表面呈水幕状流动的海水进行热交换,完成LNG的气化过程。文章对换热管束的损伤机理进行了分析,并提供了一种依据换热管束失效和周期性计划停机更换管束产生所有费用的总和最小原则计算换热管束最优更换周期的方法。由分析结果可知,换热管束损伤失效的因素主要有电化学腐蚀、微生物腐蚀、海水水质、海水冲蚀和开裂等。文章以某LNG接收站举例,采用文中所述方法计算得到该站ORV换热管束的最优更换周期。该研究结果可为ORV换热管束的维护保养和更换提供理论依据。

The heat exchange tube bundle is the key component of ORV(Open Rack Vaporizer)equipment.The LNG in the heat exchange tube bundle exchanges heat with the seawater flowing in the shape of water curtain on the outer surface to complete the gasification process of LNG.This paper analyzes the damage mechanism of the heat exchange tube bundle,and provides a method for calculating the optimal replacement cycle of heat exchange tube bundles based on the principle of minimizing the total cost incurred by heat exchange tube bundle failure and periodic planned shutdown for tube bundle replacement.The results show that the main factors of damage and failure of heat exchange tube bundle are electrochemical corrosion,microbial corrosion,seawater quality,seawater erosion,cracking and so forth.Taking an LNG terminal as an example,the optimal replacement cycle of ORV heat exchange tube bundle at the terminal is obtained byadopting the calculation method described in the paper.The results of this study can provide a theoretical basis for the maintenance and replacement of ORV heat exchange tube bundles.