基于CFD的银电阻温度计在含NOx气体中的热响应时间OA

Thermal response time t0.632 is a key parameter characterizing thermometer performance.Its magnitude directly reflects the accuracy and real-time capability of temperature measurement,thereby impacting the safe operation of the system.The thermal response time of silver resistance thermometers in NOx-containing gas media was investigated by CFD(computational fluid dynamics),examining the influence patterns of temperature,humidity,NOx gas composition and flow velocity.The results show that the simulation results deviates from the experimental results by 17.2％.Within the range of the examined parameters,the step temperature has a significant effect on the thermal response time of the thermometer,and the thermal response time is extended by 4.8 s when the step temperature is increased from 15 ℃ to 35 ℃,which is a relative extension of 4.18％.The relative humidity of the gas has almost no effect on the thermal response time of the thermometer.Under the current NOx gas composition,the increase in the ratio of N2 to NOx has a small effect on the thermal response time,which is only 1.4 s,a relative extension of 1.22％.The decrease in the diameter of the pipeline leads to an increase in the gas flow rate,which significantly reduces the thermal response time,and the thermal response time of the gas flow rate of 25 m/s is only 41.77％of that of the gas flow rate of 3.7 m/s.The simulation results provide crucial data support for optimizing the design of thermometers and improving the accuracy and red-time performance of their thermal responses.