光学学报, 2020, 40 (12): 1230001, 网络出版: 2020-06-03
激光吸收光谱系统中气室的高精度温控设计 下载: 1250次
High Precision Temperature Control Design of Gas Cell in Laser Absorption Spectroscopy System
光谱学 计算流体动力学 温度控制箱体 可调谐二极管激光吸收光谱 spectroscopy computational fluid dynamics temperature control box tunable diode laser absorption spectroscopy
摘要
在使用可调谐二极管激光吸收光谱技术(TDLAS)技术进行气体检测时,气体氛围的温度变化会影响气体的吸收谱线强度、吸收线线型及气体分子数密度,进而影响气体浓度的测量结果。设计了高精度温度控制箱体,并用其控制吸收池所处环境的温度。首先,利用CFD仿真软件模拟了目标温控箱形状、半导体致冷器位置及气流矢量等参数对箱体内部温度分布的影响;其次,利用仿真结果对温控箱的设计及加工进行优化;最后完成了温度控制箱体的制作,其可为气体吸收池提供均匀稳定的温度场。温度控制箱体的可调控制温度范围为32~50 ℃时,控制精度可达0.01 ℃,并能长期保持稳定。通过标准CO2气体浓度检测实验,对温度稳定性进行了验证。上述结果证明,利用CFD仿真优化温控装置参数,可获得均匀稳定的温度场,减小环境温度对测量结果的影响,有效提高气体浓度测量的准确度和稳定性。
Abstract
Tunable diode laser absorption spectroscopy (TDLAS) is often used for gas concentration detection. However, the change of ambient temperature affects the absorption line strength, absorption line type, and gas molecular number density and thus results in measurement errors. We designed a high precision temperature control box to control the ambient temperature where the gas cell is located. First, the effects of parameters such as the shape of the temperature control box, thermoelectric cooler position, and airflow vector on the temperature distribution inside the box were simulated using the CFD simulation software. Second, with the help of the simulation results, we optimized the design and processing of the temperature control box. Finally, we completed the fabrication of the temperature control box which can provide a uniform and stable temperature environment for the gas cell. The temperature adjustment range of this box is 32-50 ℃, the control accuracy can reach 0.01 ℃, and a long-term stability is realized. Temperature stability was verified by the CO2 gas concentration detection experiment. Therefore, using CFD simulation to optimize the parameters of the temperature control device, one can obtain a stable and uniform temperature control system, reduce the influence of ambient temperature on the measurement results, and effectively improve the accuracy and stability of gas concentration measurements.
杨曦, 孙鹏帅, 庞涛, 夏滑, 吴边, 徐启铭, 张志荣, 舒志峰. 激光吸收光谱系统中气室的高精度温控设计[J]. 光学学报, 2020, 40(12): 1230001. Xi Yang, Pengshuai Sun, Tao Pang, Hua Xia, Bian Wu, Qiming Xu, Zhirong Zhang, Zhifeng Shu. High Precision Temperature Control Design of Gas Cell in Laser Absorption Spectroscopy System[J]. Acta Optica Sinica, 2020, 40(12): 1230001.