锌精馏铅塔燃烧室变温情况下的温度测量误差

Measurement error about temperature in combustion chamber of lead column in zinc refining

为了研究韶关冶炼厂铅塔燃烧室抽气热电偶中输入单位阶跃烟气温度信号后的输出信号情况 ,对热电偶测头以及热电偶隔热罩在静态下的辐射热损失以及动态响应过程进行了分析。结果显示 :在动态响应过程中热电偶读数误差主要决定于热电偶测头以及热电偶隔热罩的辐射热损失 ,并且它的辐射热损失又受热电偶测头的滞后时间常数τ0 的限制 ;随着动态响应过程的进行 ,热电偶读数的误差急剧变化 ;当τ =3τ0 时 ,基本上可以认为动态响应过程结束 ,但升温变化时误差更大。

In order to study the case of signal exported by the thermocouple with air pump after the signal as unit pulse imported by smoke temperature due to variational temperature in combustion chamber of lead column in Shaoguan Smelter, the loss of radiant heat in static state and the course of dynamic response about the measure head of thermocouple and the cover of thermocouple were deduced and analyzed. The results are revealed that reading error of the thermocouple in the course of dynamic response is mainly caused by the loss of radiant heat of the measure top of thermocouple and the cover of thermocouple, and their loss of radiant heat is restricted by their lagging time constant τ 0; along with the process of dynamic response, reading error of the thermocouple is changed; when τ=3τ 0, the process of dynamic response basically finishes, but the change due to ascending temperature will cause bigger reading error of the thermocouple. The result of study will be more beneficial to on-line control of temperature in combustion chamber of lead column in Shaoguan Smelter.