柴油发电机组油雾保护系统的工作原理是什么？ What is the working principle of the oil mist protection system for diesel generator sets?

柴油发电机组油雾保护系统的工作原理：

油雾保护系统的主要保护元件是油雾探测器，它能及时检测出有否因轴承过热或活塞环损伤造成过量漏气等故障而导致在曲轴箱内形成油雾，从而监视柴油机的主要运行部件——曲轴和气缸的工作状况是否正常。在柴油机运行过程中它通过采样管系不停地抽出曲轴箱内的油气，并送至一个灵敏且准确的浓度测量装置。该浓度测量装置包括一个红外线发射二极管和对侧一个光电接收二级管。光电二级管感受红外线产生的光强度，并将光强度信号转换为电信号送至电子鉴定装置。如果曲轴箱气体含有油雾（使得浓度测量装置测量通道的不透明度增加），部分红外线会在测量管内被吸收，光强度会减弱，因而电信号减弱。浓度越高电信号减弱越多，当电信号降低到一个最低限值时（即油雾浓度超过最大限值时），电子鉴定装置将发出“油雾探测器高油雾”警报并停机，同时阀箱指示出是哪一部分故障引起的高油雾，以供检修人员检查。

The working principle of the oil mist protection system for diesel generator sets:

The main protective component of the oil mist protection system is the oil mist detector, which can timely detect whether there is excessive air leakage caused by bearing overheating or piston ring damage, resulting in the formation of oil mist in the crankcase, thereby monitoring the working condition of the main operating components of the diesel engine - the crankshaft and cylinder. During the operation of the diesel engine, it continuously extracts oil and gas from the crankcase through a sampling pipe system and sends it to a sensitive and accurate concentration measurement device. The concentration measurement device includes an infrared emitting diode and a photoelectric receiving diode on the opposite side. The photoelectric diode senses the light intensity generated by infrared radiation and converts the light intensity signal into an electrical signal, which is sent to the electronic identification device. If the crankcase gas contains oil mist (which increases the opacity of the measurement channel of the concentration measuring device), some infrared rays will be absorbed inside the measuring tube, and the light intensity will be weakened, resulting in a decrease in the electrical signal. The higher the concentration, the weaker the electrical signal. When the electrical signal drops to a minimum limit (i.e. when the oil mist concentration exceeds the maximum limit), the electronic identification device will issue an "oil mist detector high oil mist" alarm and shut down. At the same time, the valve box will indicate which part of the fault is causing the high oil mist for inspection by maintenance personnel.