System and method for measuring temperature and volume fraction of soot particulate matter based on LED light source

Abstract

The invention relates to a system and method for measuring the temperature and volume fraction of soot particles based on an LED light source. The system is provided with a combustion device and a light path. The combustion device is provided with a laminar flow diffusion combustor or a turbulent flow combustor; the first light path is provided with an LED point light source, a fly eye lens, two plano-convex lenses, a neutral density filter, a prism camera and a computer. The second light path is provided with an LED area light source, a neutral density filter, a prism camera and a computer. The measurement method comprises the following steps of: calculating the volume fraction of the soot particulate matters by using a light extinction method by using four groups of pictures (1) without flames and with light sources, (2) with flames and with light sources, (3) with flames and without light sources and (4) without flames and without light sources/background, and then calculating the temperature of the soot particulate matters by using a three-color method on the basis of the picture (3) in combination with an absorption coefficient obtained by the light extinction method. The temperature and the volume fraction of soot particles in the combustion process can be accurately measured at the same time. The system is simple in structure, and the measurement method is easy to operate and high in precision.

Description

Technical field [0001] The present invention relates to a system and method for measuring the temperature and volume fraction of the carbon cigarette particles based on the LED light source, and is specifically a carbon-like particulate matter discharge temperature and volume fraction based on the LED point light source or LED surface light. System and measurement method. Background technique [0002] Carbon cigarettes (also known as carbon black, soot) particulate matter is one of the important foundations of smog and PM2.5, and it is also proven to be an important factor in which the greenhouse gas effect is also proven. It is widely derived from various powered equipment (such as internal combustion engines, gas turbines and aerospace engines, etc.). Today, with the development of controlled new combustion modes and post-treatment technologies, internal combustion engine pollutants have been approximated; but relatively, the problem of particulate emissions in gas turbines hav...

AI Technical Summary

Problems solved by technology

Today, the more common and practical invasive methods include filament thermocouple temperature measurement and electric low-voltage impactor particle analysis, but invasive diagnostic methods are easy to damage the flame structure and affect the measurement of soot particles; non-invasive diagnostic methods, Mostly optical diagnostic methods with ultra-high spatial and temporal resolution, such as dichroism, extinction and tunable diode laser absorption spectroscopy

The traditional method of combining the extinction method and the two-color method to measure the temperature and concentration of soot at the same time, but the experimental accuracy is low, and the experimental optical path and experimental process are complicated, which is not conducive to the development

Among them, the temperature measurement accuracy of the two-color method is lower than that of the three-color method. In the calculation, the emission coefficient adopts a wavelength-related function model, and the error is relatively large. Moreover, the general CCD camera or CMOS camera does not have the function of adjusting the exposure time of red light, green light, and blue light separately. , the signal-to-noise ratio of the processed two-color ratio is low, which has a great impact on the experimental accuracy

The optical path of the traditional extinction method experiment is complicated, and the background effect is not considered in the establishment of the soot concentration field, which has a certain impact on the accuracy of the experiment

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