Method and device for quantitative measurement of transient combustion field

Abstract

The invention designs a method and device for quantitatively measuring a transient combustion field, belonging to the technical field of combustion diagnosis. The device includes: clock synchronization and delay trigger module, tunable laser generator module, fiber beam splitter, lens group, photodetector array, high-speed multi-channel data acquisition module, high-energy pulse laser generator module, area array photodetector, control and computing modules, etc. First, use the steady-state combustion field to calibrate the optical parameters of the laser-induced fluorescence test system; then, use the calibrated device to measure the same section of the transient combustion field; finally, the low-resolution temperature obtained by laser absorption spectrum tomography The distribution is substituted into the established laser-induced fluorescence calculation model to obtain high-resolution temperature, concentration distributions of measured groups and molecules. The invention integrates laser-induced fluorescence and laser absorption spectrum, and has important application value for monitoring and diagnosing combustion field.

Description

technical field [0001] The invention designs a method and device for quantitative measurement of transient combustion field, which belongs to the technical field of combustion diagnosis and integrates plane laser-induced fluorescence technology and laser absorption spectroscopy technology. The system is used for the temperature of transient combustion field, intermediate product group and quantitative measurement of final product molecular concentration. Background technique [0002] The measurement methods of the temperature field and gas composition of the combustion field can be mainly divided into two types: contact type and non-contact type. Contact methods mainly include thermocouple temperature measurement method, sampling analysis method, etc., which are easy to disturb the flow field, have slow response speed, and low spatial resolution. Non-contact methods mainly include acoustic method, spectroscopic method, etc. Since the sensor is not in contact with the measur...

AI Technical Summary

Problems solved by technology

The disadvantage is that it is difficult for general lasers to generate high-energy lasers on the order of picoseconds, and the gate width of ICCD cameras is not easy to reach the order of picoseconds, which is not convenient for actual engineering use

Its main disadvantage is that usually the output pulse of the laser is difficult to achieve the required saturation excitation energy density, so it is difficult to realize the two-dimensional quantitative measurement of the component concentration

In 2009, researchers such as Snyder published the paper "Double Wavelength Planar Laser-Induced Fluorescence for Measuring Optical HCCI Engines with Negative Valve Overlap" in "SAE International Journal of Engines" (SAE International Journal of Engines) Volume 2, Issue 1, Page 460-474. In Dual-wavelength PLIF measurements of temperature and composition in an optical HCCI engine with negative valve overlap, the tracer molecule 3-pentanone is added to fuel and air, and the two fluorescent lines of 3-pentanone are used to pair The temperature and composition distribution in a homogeneous charge compression ignition engine were measured, but a homogeneous flame with known temperature, pressure, and tracer molecular concentration distribution was still used in the calibration experiments

[0012] Limitations of the respective detection methods of PLIF and LAS lead to deficiencies in each measurement technique

Traditional single-wavelength PLIF can realize high-resolution display of temperature field and combustion intermediate product groups, but there are great difficulties in quantitative measurement, while LAS tomography can realize quantitative measurement of temperature field and combustion final product molecular concentration distribution, but the spatial resolution Insufficient rate

Images