Composite Combustion Chamber of Diesel Engine

The type and structural shape of the diesel engine combustion chamber are important factors affecting the formation and combustion of the diesel engine mixture. The quality of the mixture formation and the degree of perfection of the combustion process in a diesel engine directly affect the entire working process of the diesel engine.

The composite combustion chamber of a diesel engine is shaped like a deep bowl inside the piston crown, with a slightly contracted mouth. A specially shaped intake duct forms an intake vortex, and a single hole needle type fuel injector is used; The spherical combustion chamber is located inside the piston crown and is spherical in shape, belonging to a semi open combustion chamber.

The axis of the fuel injector in the composite combustion chamber of a diesel engine is basically parallel to the wall of the combustion chamber, and the fuel is sprayed into the surrounding space of the combustion chamber. Under the action of eddy currents, coarse oil particles scatter on the walls of the combustion chamber to form an oil film, while fine oil particles mix with air in space. When the rotational speed is high, the vortex velocity in the combustion chamber is high, and the amount of oil film fuel on the wall increases, exhibiting the characteristics of oil film combustion; At low speeds and starting, the vortex velocity is low, and the amount of fuel mixed in space increases, which has the characteristics of spatial combustion and can improve cold start performance.

The composite combustion chamber of diesel generators also belongs to the semi open combustion chamber. The composite combustion chamber combines the advantages of oil film evaporation mixed combustion and space mixed combustion, and is also known as a composite combustion system. The advantages of a composite combustion chamber are its soft working process, the ability to use multiple fuels, low requirements for the fuel injection system, and easy starting. The disadvantage is that the content of unburned hydrocarbons in the exhaust is relatively high at low loads, which is not conducive to environmental protection.

The fuel of the spherical oil film combustion chamber is sprayed onto the combustion chamber wall, and most of the fuel is sprayed under strong eddy currents; On the wall of the combustion chamber, a thin oil film is formed, and a small portion of fuel atomization is distributed in the combustion chamber space and ignites first, followed by igniting the fuel evaporated from the wall. This type of combustion can make the working process soft, burn completely, have a light and smokeless sound, and can use lightweight fuels; The disadvantage is that it is difficult to start at low temperatures.

(1) Structural characteristics

1. The spherical oil film combustion chamber is located at the top center of the piston, with a shape greater than half a ball. It is located opposite the fuel injector and has a notch that is tangent to the spherical surface. From here, fuel is sprayed in the direction of the airflow onto the chamber wall to form an oil film. It belongs to the direct injection combustion chamber and the oil film evaporation mixing method. 2. Adopting a strong vortex spiral inlet. 3. The bottom wall of the combustion chamber is relatively thin, and its back is cooled by oil from splashes and spray from the small end fuel injection hole of the connecting rod. 4. Use single hole or double hole nozzles.

(2) Characteristics of mixed gas formation

1. When fuel is sprayed along the tangent direction of the spherical surface along the airflow direction, about 959 hairs are evenly distributed on the chamber wall, forming a thin oil film. 5% is dispersed in the combustion chamber space to form a fire source, igniting the mixture. 2. The oil film evaporates layer by layer, rolls away layer by layer, and burns layer by layer, forming a gas vortex. 3. The fuel injection pressure is high and the fuel consumption rate is low. Can adapt to a variety of fuels with different ignition performance. 4. Heating devices (such as flame heaters) are often installed on the intake pipe.

Dingbo Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to sales@dieselgeneratortech.com we will pay highly attention on your question.