窑尾系统联接管道内烟气测温误差的分析

Error analysis of flue gas temperature measurement in connecting pipe of kiln end system

对五种热电偶,特别是双层遮热罩热电偶对窑尾系统联接管道内烟气测温误差的计算方法进行了推导。根据计算的需要,由联接管道外壁温度计算出了其内壁温度。计算了五种类型热电偶在審尾系统各联接管道位置的烟气测温相对误差d,并与相关计算和实测结果进行了对比。对热电偶测温误差的主要影响因素进行了简单计算分析。分析结果显示,使用热电偶对窑尾联接管道内烟气进行测温时的读数一般比实际值偏小,各种样式热电偶测温的相对误差范围:普通式为7.20%~16.39%,单层遮热罩式为0.69%~6.34%,单层遮热罩抽气式为0.46%~5.23%,双层遮热罩式为0.07%~2.68%,双层遮热罩抽气式为0.04%〜2.01%。相比普通热电偶,遮热罩抽气式热电偶的测温准确性大幅度提高。最后对实际生产中热电偶的选配提出了合理建议。

Five kinds of thermocouples,especially the double-layer heat shield exhaust thermocouple,were used to derive the calculation method of the flue gas temperature measurement error in the connecting pipe of kiln end system.According to the needs of calculation,the inner wall temperature was calculated from the outer wall thermometer of the connecting pipe.The relative error b of the flue gas temperature measurement of the five types of thermocouples at the joints of the kiln end system was calculated and compared with the result of calculations and measurement.The main factors affecting the temperature measurement error of thermocouple are simply calculated and analyzed.The analysis results showed that the temperature reading the flue gas in the kiln end connecting pipe by the thermocouple was generally smaller than the actual value.The relative error range of the ordinary thermocouple was 7.20%〜16.39%,and the single layer heat shield thermocouple was 0.69〜6.34%,single-layer heat shield thermocouple was 0.46%〜5.23%,double-layer heat shield thermocouple was 0.07%〜2.68%,double layer heat shield exhausted thermocouple was 0.04%〜2.01%.compared with ordinary thermocouple,The temperature measurement accuracy of the heat shield exhausted thermocouple was greatly improved.Finally,some reasonable suggestions were made for the selection of thermocouples in actual production.