Cracking furnace is the core equipment of ethylene unit. The temperature gauge at the outlet of the cracking furnace radiant section and the Venturi pressure gauge are the key measuring instruments of the cracking furnace. The rationality and reliability of their installation are the basis for the stable and optimized control of the cracking furnace. Through summarizing the installation and operation experience of key instruments of cracking furnaces in several ethylene projects in recent years, it is proposed that the measurement of COT (coil-out temperature) should use an instrument protection sleeve directly inserted wall-mounted thermocouple, and the installation position should be appropriately raised and the insulation quality should be improved to ensure the measurement accuracy of COT. The impulse tube of the Venturi pressure gauge should be laid in a 60° snake shape and the ferrule joint should be installed in the vertical section to prevent the ferrule joint from falling off and leaking due to additional stress during operation. In addition, a three-valve group anti-coking steam temperature gauge should be added, and the temperature measured by it should be used as an important parameter for operation monitoring to ensure the smooth operation of the anti-coking steam, providing a guarantee for the long-term, stable and efficient operation of the unit.

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裂解炉是乙烯装置的核心设备，裂解炉辐射段出口热电偶、文丘里压力表等是裂解炉的关键测量仪表，其安装的合理性和可靠性是裂解炉平稳运行、优化控制的基础。总结多个乙烯项目裂解炉关键仪表的安装和运行经验后提出：辐射段炉管出口温度（COT）测量宜采用仪表保护套管直接插入式贴壁热电偶，适当上移安装位置，可提高保温质量，确保COT测量准确性；文丘里压力表引压管宜采用60°蛇弯式敷设并将卡套接头安装在垂直段，以防止运行中的附加应力造成卡套接头脱落导致泄漏；增设裂解气三阀组防焦蒸汽热电偶，将防焦蒸汽温度作为重要运行监控参数，确保防焦蒸汽运行畅通，保障装置长周期、高效益稳定运行。

margin:0px 0px 16px, padding:0px, border:0px, font-size:16px, vertical-align:baseline, color:rgba(0, 0, 0, 0.9), background-color:#FFFFFF, "> 裂解炉, 乙烯装置, 测量仪表, COT, 文丘里压力表, 裂解气大阀, 防焦蒸汽