针对有机热载体炉火灾的关键因素积碳层，提出利用超声导波对其厚度进行定量检测的方法。阐述了超声导波检测原理和检测系统。然而，由于管道超声导波具有多模态和频散特性，利用时频分析对炉管积碳检测的超声导波模态进行识别。接收信号的时频分析结果与L(0,2)模态的理论频散曲线较为拟合。并且通过时差法确定接收信号的实验群速度与理论群速度相对误差仅为1.88%~3.48%。从而确定接收信号主要为L(0,2)模态。该研究结果为基于超声导波的有机热载体炉积碳检测技术奠定了基础。（蓝色部分为修改意见1的修改）

Carbon deposition of organic heat transfer heater is a key factor for the fire risk assessment. In this paper, ultrasonic guided wave was used for the carbon layer detection of organic heat transfer heater. Also, the detection principle and its test system were described. However, due to multi-mode and dispersive nature of ultrasonic guided waves in pipes, time-frequency analysis was used for the identification of ultrasonic guided wave modes for carbon layer inspection. Time-frequency representation of received signal is closed to theoretical dispersion curve of L(0,2) mode. Furthermore, the relative error of experimental group velocity of received signals and theoretical group velocity is only 1.88%~3.48% by time difference method. Therefore, received signals mainly consist of L(0,2) mode. The research results provide a significant theoretical foundation for the carbon layer detection technology of the organic heat transfer heater.（蓝色部分为修改意见1的修改，英文摘要已经重写，实验部分为过去式，实验结果为一般现在时，做到简短、明了和达意）