高温高压条件下新型热电偶密封结构分析与研究

常用的高温高压热电偶是采用护套的安装方式，护套很厚使得温度测量的响应速度以及准确度大大降低。文章提出了一种新型的适用于高温高压管道的自紧式热电偶密封结构，该结构不需要使用保护护套，热电偶可直接与管道内介质接触，提高响应速度，减小测量误差。为验证该结构设计的合理性，通过有限元法对该结构进行了密封性和热应力的分析，计算结果表明该结构最少能够满足15MPa，350℃条件下使用的要求且不会发生密封螺纹的咬死问题。同时，对该结构试件进行了冷态以及热态验证试验。试验结果表明，该结构能够承受70MPa的冷态静压以及满足15MPa，344℃的运行环境要求。

The Analysis and Research on New Thermocouple Seal Structure Under High Temperature and Pressure Conditions

Thermocouples used in high temperature and pressure are commonly using the protective seat, the seat is very thick that the response speed and the temperature measurement accuracy is greatly reduced. This paper presents a late-model self-tight thermocouple structure for high-temperature and high-pressure pipeline, this structure don’t require the protective sheath, and the thermocouple directly contacts with the media in the pipeline, which will improve the response speed and reduce measurement error. In order to verify the reasonableness of this structure, the finite element method was used to analyze the structure sealing and thermal stress, the hydrostatic test was taken for testing the structure. The calculation results indicate that at least the structure can bear 15MPa, 350℃condition without leakage and thread galling problems. Furthermore, the hydrostatic test shows that the structure can withstand the pressure of 70MPa and the thermal state test shows that the structure also works well under the condition of 15MPa, 344℃.