Study On Alcohol Hccl Combustion Boundary Conditions

The motive of the research in the field of Internal Combustion Engine is to resolve the energy problem of the world. Non renewable energy resource and it's pollution puzzling us increasingly with the development of the society and economic. New alternative fuels must be developed before the dry up of the fossil energy sources. Accordingly, new combustion mode is also need to be developed to match new fuels. So the research of Alcohol's combustion in HCCI mode is just for this purpose. At last, the mechanism of the combustion and kindling can be discovered as well as the combustion control strategy by the research of this kind of alternative fuel combusted in HCCI mode. According to the project of "The Development of The Multi-functional Combustion Bomb and The Research of Mechanism of Alcohol's Combustion and kindle in HCCI Mode", which belongs to "the National Fundamental Research Development Program", the effect of the boundary conditions to the combustion status and the ignition occurred range of the Alcohol in HCCI mode will be investigated in this study. As a result, the study can be divided into two parts: (1) The study on the effect of the boundary conditions to the Alcohol HCCI combustion .In this part, the intake air temperature, the pressure in the cylinder and the air-fuel ratios will be observed as the boundary parameters and the effect of these parameters to Alcohol HCCI combustion will be studied as well. So, the kindling time, the heat release ratios, the pressure increasing ratios, the combustion duration and the percent combustion completed time(T50c ) during the Alcohol combustion process will be researched to evaluate the combustion characteristic. (2) The judge of the kindling range of Alcohol HCCI combustion on the Multi-functional Combustion Bomb. The main purpose of this part is to find out two facts of Alcohol HCCI combustion's kindling range. The first purpose is to testify the relationship between the kindling critical temperature and the kindling critical pressure. The second is to find out the kindling critical limitation in the aspect of mixture's concentration. The correlative program has been made out to meet the need of this study. One of the most important part of the program is to build up a Multi-functional Combustion Bomb. The Multi-functional Combustion Bomb is composed by three systems: the driven system, the air-fuel mixture confect system and the combustion system. As a result, several steps must be executed before the study proceeded on this bomb. First, the air-fuel mixture confect system should be warm-up to a certain temperature. After this step, the alcohol will be injected into a air-fuel mixer in liquid state with a certain volume which is decide by the air-fuel ratios we needed. Through a venturi tube equipped in the air-fuel mixer the alcohol will be pressed into the blending chamber by the intake air mass. Subsequently, the air-fuel mixture will be preheated in the blending chamber. At last, the air-fuel mixture will be transported into the combustion chamber and kindled by the compression of the piston. Accordingly, the combustion date will be recorded by the computer. A data collecting system and a boundary parameters monitor have also been designed on the combustion bomb, so the in-cylinder pressure, the displacement of the piston, the in-cylinder temperature will be recorded into the computer correspondingly. And also, the operation of the combustion bomb will be monitored simultaneously. Through the study on the effect of the boundary conditions to the Alcohol HCCI combustion, the kindling time, the heat release ratios, the pressure increasing ratios, the combustion duration and the percent combustion completed time(T50c ) during the Alcohol combustion process have been evaluated. Under the condition of compression ratio equaled to 55, we have drawn a conclusion that when the intake air temperature increased, the...