阶梯形温度计套管的工程应用设计方法

A design method of step-shank thermowells for engineering application

在工程应用中,有锥形、直形和阶梯形等多种形式的温度计套管被使用,常见的是锥形和直形温度计套管。虽然阶梯形温度计套管因其良好的温度特性而受到青睐,但由于缺乏振动频率计算和评估方法,缺少对其在共振情况下和非共振情况下的受力分析,使得阶梯形温度计套管的应用受到限制。根据ASME PTC19.3 TW—2010"Themowells Performance Test Codes"提供的准则,通过对阶梯形温度计套管振动频率、静态应力和动态应力的分析,建立了相应的频率极限限制条件、动态应力极限限制条件以及静态应力极限限制条件,提出了阶梯形温度计套管的工程应用设计方法。从设计资料准备到各种限制条件的计算评估等给出具体的设计步骤,并结合计算实例,介绍了这个方法的具体应用。

There are many types of thermowells, such as tapered, straight and step-shank for engineering applications. However, the tapered and straight ones are commonly used. Although the step-shank thermowell is favored because of its good temperature performances, the application of step-shank thermowells is limited due to the lack of calculation and evaluation methods of vibration frequency and stress analysis under resonant and non-resonant conditions. Based on ASME lYl＇Clg. 3 TW--2010 ＂Thermowells Performance Test Codes＂, the relevant limits of frequency are established by analyzing the vibration frequency, steady-state static and dy- namic stress analysis of step-shank thermowells. An appropriate design method of step-shank thermowells for engineering application is presented. Specific design procedures are described from design information prepa- ration to calculations of various limit conditions. A case study is illustrated for engineering application, and this method can be directly applied in engineering design.