Use of an assembly of two thermal conductometric sensors for detection of hydrogen emissions

The work shows the possibility of using an assembly of two thermоconductometric sensors to simultaneously measure the flow speed of a gas mixture and the hydrogen content in it. A measurement concept has been proposed using one sensor located in the flow of the test gas, and a second one closed with a mesh cap, which reduces the dependence of the sensor readings on the flow speed. Test assemblies were manufactured and calibration experiments were carried out in the range of speeds from 0 to 1.84 m/s, hydrogen concentrations from 0 to 100 vol.% and absolute pressure from 0.1 to 5 atm. The results of calibration experiments show that from the signals from two sensors it is possible to unambiguously obtain the flow speed values and hydrogen content in the gas mixture at the location of the sensors. Formulas for converting signals into the required physical quantities are obtained. The assemblies are installed in a test container to study the mixing of hydrogen with air. The response time of the assembly to changes in hydrogen concentration does not exceed 1 s, which allows its use for signaling hydrogen emissions and studying the mixing of hydrogen with air. Graphs of the flow rate and concentration of hydrogen in the mixture versus time are presented.