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.

低速柴油機和部分中、高速柴油機主要用無渦流的開式燃燒室。燃燒室由氣缸蓋底面和活塞頂面形成，具有一定形狀的整體空間。多孔噴油器(6～10孔)能使燃油霧化良好，并均勻分布在燃燒室空間。因此，開式燃燒室中的燃燒屬于典型的空間式燃燒過程，要求燃燒室與油束形狀和分布相配合。它的優點是燃料消耗率低，起動容易；缺點是燃料霧化要求高，難于適應變轉速工作。

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.

小型高速柴油機大多采用有渦流的半開式燃燒室。這種燃燒室又分為多種類型，主要有油膜式燃燒室和復合式燃燒室等。

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.

油膜式燃燒室是1956年由德國的莫勒所發明。燃燒室位于活塞頂內，呈球形。燃料噴向燃燒室壁面，大部分燃油在強渦流作用下噴涂在燃燒室壁面上，形成很薄的油膜，小部分燃油霧化分布在燃燒室空間并著火，隨后即引燃從壁面上蒸發的燃料。這種燃燒室可使工作過程柔和，燃燒完全，聲輕無煙，并可使用輕質燃料；缺點是低溫時起動較困難。

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.

復合式燃燒室是1964年由的史紹熙等發明，燃燒室在活塞頂內呈深盆形，口部略有收縮，用特殊形狀的進氣道形成進氣渦流，采用單孔軸針式噴油器。噴油器軸線與燃燒室壁面基本平行，燃料噴向燃燒室的周邊空間。在渦流作用下，粗大的油粒散落在燃燒室壁面上形成油膜，細小的油粒在空間與空氣混合。當轉速較高時，燃燒室渦流速度高，壁面上的油膜燃料增多，具有油膜燃燒的特點；而在低轉速和起動時，渦流速度低，空間混合的燃料量增多，具有空間式燃燒的特點，能改善冷起動性能。

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.

復合式燃燒室把油膜蒸發混合燃燒與空間混合燃燒合理地結合起來，兼有兩者的優點，故又稱為復合式燃燒系統，其工作過程柔和，可燃用多種燃料，對噴油系統要求低，而且起動容易。缺點是低負荷排氣中未燃的碳氫化物含量較高。

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.

預燃式燃燒室由預燃室和主燃燒室兩部分組成。預燃室在氣缸蓋內，占壓縮容積的25～40％，有一個或數個通孔與主燃燒室連通。燃料噴入預燃室中，著火后部分燃料燃燒，將未燃的混合物高速噴入主燃燒室，與空氣進一步混合燃燒。這種燃燒室適用于中小功率柴油機。

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.

渦流式燃燒室由渦流室和主燃燒室組成。渦流室位于氣缸蓋上，呈球形或倒鐘形，占總壓縮容積的50～80％，有切向通道與主燃燒室相通。在壓縮行程時，壓入渦流室的空氣產生強烈的渦流運動，促使噴入其中的燃料與空氣混合。著火后混合物流入主燃燒室，形成二次流動，進一步與主燃燒室內的空氣混合燃燒。

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.

渦流室燃燒室和預燃室燃燒室都用軸針式噴油器，噴油壓力較低，工作可靠；由于渦流室內渦流隨轉速增高而加強，柴油機高轉速時柴油和空氣仍能很好地混合。

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.