基于波长调制技术的高温高压流场温度测量方法

Temperature measurement method of high temperature and high pressure flow field based on wavelength modulation spectroscopy technology

温度是衡量燃烧效率的重要参数之一,温度的测量对工业燃烧过程的节能减排控制和发动机状态诊断等都具有重要意义.可调谐半导体吸收光谱技术是一种非侵入式测量技术,具有较强的环境适应性,可实现快速、原位检测.本文基于H2O在7185.6, 6807.8以及7444.35/37 cm^–1三条吸收线集成测量系统,三只激光器为时分复用方式,选择波长调制技术,利用扣除背景的1f归一化2f信号反演燃烧流场温度,通过直接比较实际测量的谐波信号与建立的吸收模型获得的谐波信号,实现了某型号发动机模型喷口温度的准确测量,测量系统时间分辨小于1 ms,最高测量温度和最大压强可到1512 K和10.58 atm (1 atm=1.013×10^5 Pa),测量误差小于5.68%,验证了该测量方法的实用性和系统的稳定性.

Temperature is one of the important parameters to measure the combustion efficiency. The measurement of temperature is of great significance for saving energy and reducing emission in industrial combustion process and diagnosing the engine state. The tunable diode laser absorption spectroscopy is a non-invasive measurement technology with strong environmental adaptability for fast, in-situ detection. Based on the three absorption lines of H2O at 7185.6 cm^–1, 6807.8 cm^–1 and 7444.35/37 cm^–1, the wavelength modulated spectrum absorption model is established and laboratory-calibrated;using the background-subtracting WMS-2 f/1 f method and the best fit method, the temperature is measured. The outlet temperature of the single-head combustion chamber is accurately realized. The outlet temperature of the single-sector combustion chamber is also accurately measured. The measurement is verified in a pressure range of 3.39-10.58 atm and a temperature range of 958-1512 K. The time resolution of the measurement system is less than 1 ms, and the measurement error is less than 5.68%, thus verifying the practicality of the measurement method and the stability of the measurement system.