A bare wire type small inertia thermocouple

Abstract

The invention provides a wire-exposed type small-inertia thermocouple and belongs to the technical field of testing of the performances of an aero-engine. The wire-exposed type small-inertia thermocouple is good in dynamic performance and long in service life. The wire-exposed type small-inertia thermocouple comprises a thermocouple protecting sleeve and a thermode. The thermocouple is characterized in that the temperature measuring end, facing the direction of an air stream, of the thermode is of an n shape which is wide outside and narrow inside; the temperature measuring end of the thermode is bended upwards along the middle portion parallel to the side where a hot junction is located so that a right angle form can be obtained, and therefore the side where the hot junction is located faces the direction of the air stream; the bended end is perpendicular to the center line of the thermocouple protecting sleeve and the other end and the bended end are perpendicular to each other.

Description

technical field [0001] The invention belongs to the technical field of aero-engine performance testing, in particular to a bare wire type small inertial thermocouple. Background technique [0002] In the performance test of aero-engine development and production, small inertial thermocouples are often used to monitor the real temperature of the measured airflow with the fastest response speed, so as to prevent the gas from overheating and ablate engine components. The structure of the commonly used small inertia thermocouple adopts the ring bare wire type, such as figure 1 , figure 2 As shown, the hot electrode of the thermocouple with this structure is prone to fatigue fracture under the scour of high temperature and high-speed gas flow and the high-frequency vibration generated, and its service life is 5 to 6 hours on average, and the damage is mainly concentrated in the heat electrode root. Due to the fragility of this type of small inertia thermocouple, it needs to b...

AI Technical Summary

Problems solved by technology

The structure of the commonly used small inertia thermocouple adopts the annular bare wire type, such as figure 1 , figure 2 As shown, the hot electrode of the thermocouple with this structure is prone to fatigue fracture under the scour of high temperature and high-speed gas flow and the high-frequency vibration generated, and its service life is 5 to 6 hours on average, and the damage is mainly concentrated in the heat Electrode root

Due to the fragility of this type of small inertia thermocouple, it needs to be replaced frequently in the performance test of aero-engine development and production, which not only increases the production cost, but also affects the safety of the engine test

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