Experimental system for measuring propagation speed of laminar premixed flame under high pressure

Abstract

The invention discloses an experimental system for measuring propagation speed of a laminar premixed flame under high pressure. The experimental system is fixed to a rack, a laser and an ICCD camera are arranged at the positions, opposite to two observation windows, on a high pressure cavity, and the ICCD camera is connected with a computer. A constant pressure valve is arranged at the top of the high pressure cavity, a high-pressure nitrogen connector and a nozzle are arranged at the bottom of the high pressure cavity, and the high pressure cavity is inflated with high-pressure nitrogen through the nitrogen connector. Preheated oxidants and preheated fuel are sprayed into the high pressure cavity through the nozzle after passing through a premixer, premixed gas is ignited by a sparking plug, and the numerical value of a volume flowmeter is read. The propagation speed of the laminar premixed flame is calculated according to the numerical value of the volume flowmeter and the area of an outlet of the nozzle. The laminar premixed flame propagation speed under different equivalence ratios is acquired by adjusting the flow of the oxidants and the fuel. The laminar premixed flame propagation speed under different environmental pressures is acquired by changing the pressure of the high pressure cavity. Flame component distribution diagrams and temperature profiles under all work conditions are acquired through a PLIF system.

Description

technical field [0001] The invention relates to an experimental system for measuring laminar premixed flame propagation velocity under high pressure, in particular to an experimental system for measuring the unstretched laminar premixed flame propagation velocity of preheated fuel and oxidant under high pressure environment. Background technique [0002] Laminar premixed combustion is an important content in the study of combustion mechanism and an important means to develop and verify the kinetic mechanism of chemical reaction of fuel combustion. At present, the establishment of a theoretical model based on the kinetic mechanism of chemical reactions to simulate and calculate the characteristics of laminar flames is limited to some small molecular gases. Experiments are still an effective method to study the characteristics of laminar flames. The experimental methods for measuring laminar premixed flame propagation velocity can basically be divided into two categories: one ...

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Problems solved by technology

It can measure the laminar premixed flame propagation velocity of many gaseous fuels and oxidants under different pressures, but there are still some shortcomings in constant volume incendiary bombs: first, the relationship between flame stretch and flame propagation velocity needs to be established to obtain No stretching flame propagation speed; second, due to the compression-expansion effect caused by the flame propagation in the constant volume incendiary bomb, even in the constant volume incendiary bomb where the air flow is still, the airflow movement will be caused, and the direction of motion at the initial stage of combustion is the same as that of the combustion The final stage is the opposite, which causes the flame propagation speed to accelerate first and then decelerate, so there is a large error; third, it is impossible to measure the laminar flow premixing of the preheated gaseous liquid fuel or gaseous fuel and oxidant under high pressure environment Flame propagation speed; Fourth, it is difficult to use the PLIF system to obtain the laminar premixed flame component distribution map and the laminar premixed flame temperature distribution map

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