Evaporation mixing combustion mode for liquid fuel and combustion chamber therefor

[0017] The present invention will be further described below in conjunction with the drawings and embodiments.

[0018] figure 1 , The combustion chamber 9 is divided into three areas: evaporation area 3, mixing area 5 and combustion area 8. The fuel is gasified in the evaporation zone 3, which is brought into the evaporation zone 3 by the primary air, and then through a reasonable secondary air organization, the gasified liquid fuel is fully mixed in the mixing zone 5 and is being mixed. The zone 5 is close to the auto-ignition temperature. By setting the necking and the necking plate 7 and vent 6 between the mixing zone 5 and the combustion zone 8, the fuel can achieve homogeneous and lean combustion in the combustion zone 8, thereby controlling NOx pollution The generation of things.

[0019] The evaporation zone 3 is near the closed end of the combustion chamber 9 and is mainly an area where fuel evaporates or gasifies. At the closed end of the combustion chamber 9 there is a metal wire cake-shaped disc 1 made of high temperature resistant (500℃) metal wire. Liquid fuel such as gasoline is first delivered to the metal wire disc 1 through a low-pressure electromagnetic pump for storage and ignition The glow plug is arranged close to the metal wire pie-shaped plate 1. After power on, the glow plug heats up to incandescent within a few seconds. During this process, the gasoline in the cake around the glow plug is heated and evaporated, and the evaporated gasoline runs along the primary air supply hole 2 The downward airflow is taken away and enters the mixing zone 5; the evaporation zone 3 also receives the hot air returned after combustion to further increase the temperature of the evaporation zone 3, thereby achieving fuel evaporation.

[0020] The mixing zone 5 is located under the evaporation zone 3. The structural feature of the combustion chamber 9 in this zone is that there are multiple secondary air supply holes 4 on the wall, and the combustion-supporting air is mainly supplied from this through the function of small holes. A strong vortex is formed in the combustion chamber 9. The axis of the main vortex basically coincides with the centerline of the combustion chamber barrel, and has a downward trend. The center of the vortex forms a low pressure area to create conditions for the gas to flow upward to the evaporation zone 3. At the same time, a lot of gas will be continuously sucked into the vortex from the central area, increasing the temperature of the vortex area. The effect of the vortex makes the gasified fuel brought down by the gas from the evaporation zone 3 and the air uniformly mix to form a combustible mixture. This area cannot yet form a strong combustion phenomenon. The combustible mixture formed by the relatively low temperature of the newly entered combustion air needs a combustible mixture. The process of further heating. The characteristics of this area are that the vortex is strong, the temperature is not too high, the mixed gas concentration is moderate, the physical and chemical processes in the early stage of combustion are well prepared, and the temperature gradually rises to approach the autoignition temperature.

[0021] The combustion zone 8 is located below the mixing zone 5, and the combustible mixture gas undergoes preliminary reaction and heating to increase the temperature to form combustion, which is a concentrated heat release zone. However, excessively concentrated heat release will result in high temperature. In the actual situation where the excess air coefficient is greater than 1, a large amount of harmful NOx emissions will be generated. At the same time, it is also a severe challenge to the structural materials of the combustion chamber 9, so at the beginning of the combustion zone of the combustion chamber 9. A protruding necking and a necking plate 7 are arranged near the section, and a plurality of vent holes 6 are set on the necking plate 7. Its function is to force the gas to form a backflow along the vortex center of the mixing zone 5 and the other is Strong turbulence is formed before and after the necking, which further promotes the uniform mixing of fuel and air, especially in the sudden expansion area downstream of the necking outlet, where the turbulence is strong, the temperature is high, and the fuel reacts sufficiently in advance. When the excess air coefficient is appropriate, The conditions of homogeneous lean combustion are formed, the combustion is more complete, the heat release area is expanded, and the maximum combustion temperature is controlled, thereby controlling NOx emissions.