Cavitation: it occurs around the engine combustion chamber. Although the feedback from the vehicle water temperature gauge is about 90 °, the engine combustion work, especially most wet cylinder liners, the temperature of local surface exceeds the boiling point of water, which is much higher. When water is near the boiling point, a large number of bubbles will be generated, which repeatedly impact the cylinder liner surface, and the pressure of the shock wave under the micro level reaches 15-20000 psi. In our daily life, when the teapot is boiling, the bubbles generated at the bottom of the pot are similar.

发动机使用的冷却液，通常沸点温度超过130度。如果破坏冷却液的成分比例，乙二醇成分减少。气缸套暴露在较低的沸点下，醇类物质无法附着在表面。穴蚀发生将无法避免，例如200小时后，兑水后的冷却液实验，发动机已经产生缸套激烈气蚀情况，产生更严重的穴蚀。

The coolant used in the engine usually has a boiling point temperature of more than 130 degrees. If the composition ratio of the coolant is destroyed, the ethylene glycol composition will be reduced. The cylinder liner is exposed to a low boiling point and alcohols cannot adhere to the surface. Cavitation cannot be avoided. For example, in the coolant test after mixing water 200 hours later, the engine has produced severe cavitation in the cylinder liner, resulting in more serious cavitation.

为什么有些全自动混凝土搅拌机的发动机加水表面看起来很正常?

Why does the water adding surface of some automatic concrete mixer engines look normal?

中等排量发动机：冷却系统要求不高腐蚀状况较突出

Medium displacement engine: the cooling system does not require high corrosion

国内中等排量的发动机，从上世纪70年代技术上演变而来，仅相当于国外50年代的水平，本质上并没有改变。因此发动机设计之初，冷却系统要求不高，燃烧室并没有强化，气蚀现象同样存在，但并非明显感受，相比腐蚀状况就比较突出，例如烂水堵。

Domestic medium displacement engines have evolved technically from the 1970s, only equivalent to the level of foreign engines in the 1950s, and have not changed in essence. Therefore, at the beginning of the engine design, the requirements for the cooling system are not high, the combustion chamber is not strengthened, and the cavitation phenomenon also exists, but it is not obvious. Compared with the corrosion condition, it is more prominent, such as rotten water blocking.

现今国产大排量卡车发动机，采用了增压，高压缩比，活塞行程缩短，转速更低，这样的强化设计，燃烧室的局部温度，强制散热要求，多通过活塞机油喷嘴，更高的冷却液循环量，和使用更高沸点温度的冷却液来实现。因此冷却液少量补充水，短期内可以应急，长时间使用弊大于利，一个局部频繁“开锅”的发动机，寿命大大缩短。

Nowadays, domestic large displacement truck engines adopt supercharging, high compression ratio, shortened piston stroke and lower speed. Such enhanced design, local temperature of combustion chamber and forced heat dissipation requirements are mostly realized through piston oil nozzle, higher coolant circulation and coolant with higher boiling point temperature. Therefore, a small amount of coolant make-up water can be used for emergency in a short time. The disadvantages of long-term use outweigh the advantages. The service life of an engine with local frequent "boiling" is greatly shortened.

今天这篇文章为大家讲解了全自动混凝土搅拌机的气缸套致命气蚀穴蚀的知识，大家以后再遇见这种情况应该可以很好的了吧！

Today's article explains the knowledge of fatal cavitation of cylinder liner of full-automatic concrete mixer. You should be able to solve this situation in the future!