According to the characteristics and structure of organized combustion process, combustion chamber can be divided into open type, semi open type, precombustion chamber type and vortex chamber type. The first two belong to direct injection combustion chamber; The latter two types belong to separated combustion chambers.

低速柴油机和部分中、高速柴油机主要用无涡流的开式燃烧室。燃烧室由气缸盖底面和活塞顶面形成，具有一定形状的整体空间。多孔喷油器(6～10孔)能使燃油雾化良好，并均匀分布在燃烧室空间。因此，开式燃烧室中的燃烧属于典型的空间式燃烧过程，要求燃烧室与油束形状和分布相配合。它的优点是燃料消耗率低，起动容易；缺点是燃料雾化要求高，难于适应变转速工作。

Low speed diesel engines and some medium and high speed diesel engines mainly use open combustion chambers without vortex. The combustion chamber is formed by the bottom surface of the cylinder head and the top surface of the piston, with a certain shape of the overall space. The multi hole injector (6 ~ 10 holes) can make the fuel atomize well and distribute evenly in the combustion chamber space. Therefore, the combustion in open combustion chamber belongs to a typical spatial combustion process, which requires the combustion chamber to match with the shape and distribution of oil beam. It has the advantages of low fuel consumption and easy starting; The disadvantage is that the fuel atomization requirements are high and it is difficult to adapt to variable speed operation.

小型高速柴油机大多采用有涡流的半开式燃烧室。这种燃烧室又分为多种类型，主要有油膜式燃烧室和复合式燃烧室等。

Small high-speed diesel engines mostly use semi open combustion chamber with vortex. This combustion chamber can be divided into many types, mainly oil film combustion chamber and compound combustion chamber.

油膜式燃烧室是1956年由德国的莫勒所发明。燃烧室位于活塞顶内，呈球形。燃料喷向燃烧室壁面，大部分燃油在强涡流作用下喷涂在燃烧室壁面上，形成很薄的油膜，小部分燃油雾化分布在燃烧室空间并着火，随后即引燃从壁面上蒸发的燃料。这种燃烧室可使工作过程柔和，燃烧完全，声轻无烟，并可使用轻质燃料；缺点是低温时起动较困难。

Oil film combustion chamber was invented by Moeller of Germany in 1956. The combustion chamber is located in the piston crown and is spherical. The fuel is sprayed to the combustion chamber wall. Most of the fuel is sprayed on the combustion chamber wall under the action of strong eddy current to form a very thin oil film. A small part of the fuel is atomized and distributed in the combustion chamber space and ignites first, and then ignites the fuel evaporated from the wall. The combustion chamber can make the working process soft, complete combustion, light sound and smokeless, and can use light fuel; The disadvantage is that it is difficult to start at low temperature.

复合式燃烧室是1964年由的史绍熙等发明，燃烧室在活塞顶内呈深盆形，口部略有收缩，用特殊形状的进气道形成进气涡流，采用单孔轴针式喷油器。喷油器轴线与燃烧室壁面基本平行，燃料喷向燃烧室的周边空间。在涡流作用下，粗大的油粒散落在燃烧室壁面上形成油膜，细小的油粒在空间与空气混合。当转速较高时，燃烧室涡流速度高，壁面上的油膜燃料增多，具有油膜燃烧的特点；而在低转速和起动时，涡流速度低，空间混合的燃料量增多，具有空间式燃烧的特点，能改善冷起动性能。

The compound combustion chamber was invented by Shi Shaoxi of China in 1964. The combustion chamber is in a deep basin shape in the piston crown, the mouth shrinks slightly, the intake vortex is formed with a special shape intake port, and a single hole shaft needle injector is adopted. The axis of the injector is basically parallel to the wall of the combustion chamber, and the fuel is injected into the surrounding space of the combustion chamber. Under the action of eddy current, coarse oil particles scatter on the wall of combustion chamber to form oil film, and fine oil particles are mixed with air in space. When the rotating speed is high, the swirl velocity of the combustion chamber is high, and the oil film fuel on the wall increases, which has the characteristics of oil film combustion; At low speed and start-up, the vortex speed is low and the amount of fuel mixed in space increases. It has the characteristics of space combustion and can improve the cold start performance.

复合式燃烧室把油膜蒸发混合燃烧与空间混合燃烧合理地结合起来，兼有两者的优点，故又称为复合式燃烧系统，其工作过程柔和，可燃用多种燃料，对喷油系统要求低，而且起动容易。缺点是低负荷排气中未燃的碳氢化物含量较高。

Compound combustion chamber reasonably combines oil film evaporation mixed combustion with space mixed combustion, which has both advantages. Therefore, it is also called compound combustion system. Its working process is soft, it can use a variety of fuels, has low requirements for fuel injection system, and it is easy to start. The disadvantage is that the unburned carbon hydride content in low load exhaust is high.

预燃式燃烧室由预燃室和主燃烧室两部分组成。预燃室在气缸盖内，占压缩容积的25～40％，有一个或数个通孔与主燃烧室连通。燃料喷入预燃室中，着火后部分燃料燃烧，将未燃的混合物高速喷入主燃烧室，与空气进一步混合燃烧。这种燃烧室适用于中小功率柴油机。

The precombustion combustion chamber consists of a precombustion chamber and a main combustion chamber. The precombustion chamber is in the cylinder head, accounting for 25 ~ 40% of the compression volume, and one or more through holes are connected with the main combustion chamber. The fuel is injected into the precombustion chamber, part of the fuel is burned after ignition, and the unburned mixture is injected into the main combustion chamber at a high speed for further mixed combustion with air. The combustion chamber is suitable for medium and small power diesel engines.

涡流式燃烧室由涡流室和主燃烧室组成。涡流室位于气缸盖上，呈球形或倒钟形，占总压缩容积的50～80％，有切向通道与主燃烧室相通。在压缩行程时，压入涡流室的空气产生强烈的涡流运动，促使喷入其中的燃料与空气混合。着火后混合物流入主燃烧室，形成二次流动，进一步与主燃烧室内的空气混合燃烧。

The swirl combustion chamber consists of a swirl chamber and a main combustion chamber. The swirl chamber is located on the cylinder head and is spherical or inverted bell shaped, accounting for 50 ~ 80% of the total compression volume. There is a tangential channel connected with the main combustion chamber. During the compression stroke, the air pressed into the vortex chamber produces strong vortex motion, which makes the fuel injected into it mix with the air. After ignition, the mixture flows into the main combustion chamber to form a secondary flow, which is further mixed with the air in the main combustion chamber.

涡流室燃烧室和预燃室燃烧室都用轴针式喷油器，喷油压力较低，工作可靠；由于涡流室内涡流随转速增高而加强，柴油机高转速时柴油和空气仍能很好地混合。

Both swirl chamber combustion chamber and precombustion chamber use axial needle injector, which has low injection pressure and reliable operation; Because the swirl in the swirl chamber is strengthened with the increase of speed, diesel and air can still be well mixed at high speed.