A dynamic temperature measurement method for systematically correcting thermocouple thermal inertia drift

Abstract

The invention relates to a dynamic temperature measuring method for correcting the thermal inertia drift of a system thermocouple. According to the method, thermocouples of different thermocouple wire / node diameters are simulated and analyzed in the numerical calculation mode. During the temperature response process in the flame, a thermocouple wire / node accouplement optimal in thermal inertia stability is screened out. According to the requirement of the above accouplement, a thermocouple is customized, so that the purpose of correcting the thermal inertia drift is achieved. During measurement, a thermocouple node is quickly moved into a specified measurement point in the flame. The temperature / time data of the thermocouple are recorded and analyzed by a data acquisition module and a computer. Based on the second-order difference quotient characteristics of a thermocouple temperature and time sequence, a time interval that is stable in thermal inertia is screened out. After that, the data treatment of a first-order system response equation is conducted in the above time interval, so that a thermal inertia coefficient and a flame temperature are obtained. The above method is wider in applicability and higher in accuracy compared with the traditional thermocouple temperature measuring method.

Description

technical field

[0001] The invention relates to a dynamic temperature measurement method for systematically correcting thermocouple thermal inertia drift, belonging to the field of measurement technology. Background technique

[0002] Thermocouple is a commonly used temperature measuring element in temperature measuring instruments. It directly measures the temperature and converts the temperature signal into a thermal electromotive force signal, which is convenient for the transmission, recording and processing of measurement data. Thermocouples can usually be divided into steady-state method and dynamic method in temperature measurement. The steady-state method is a more commonly used general method, which is suitable for occasions where the measured temperature is lower than the melting point of the thermocouple, and it needs to consider radiation and heat conduction error correction. For the measurement of high-temperature flames, in many cases, the measured temperature...

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