Abstract: Based on acoustics theory, the acoustic pressure field varying with the gas pressure change in an acoustic enclosure with sound-absorption treatment is formulated. Combining the acoustic enclosure technique with PLC technique, an intelligent acoustic enclosure is designed for the machines which are always working under dynamic loads. The noise insulation of the enclosure can be adjusted according to the variation of noise radiation energy by changing the vacuum of the acoustic enclosure. The noise insulation is controlled by a system which consists of transducer, PLC, servo motor, etc. This acoustic enclosure has many advantages over the traditional one. It can isolate the noise with different frequency bands and is easy to realize automation and intellectuality. The validity of the method and design is confirmed by a more-than-one-year application in a gas compressor workshop.

Key words: acoustics, noise insulation, intelligent control, acoustic enclosure

摘要： 为了满足机械设备在变工况条件下运行的噪声控制需要，在声学理论的基础上推出作吸声处理隔声罩内任一点的声压随气体媒质压强的变化公式，并将隔声罩技术与PLC控制技术相结合，设计出一种可以根据噪声辐射的强弱自动调整隔声量的智能隔声罩。该隔声罩通过改变罩内的真空度，来对其隔声量进行调节，整个过程是由传感器、PLC及伺服电机等组成的控制系统来实现，能同时完成对低频、中频和高频噪声的控制，具有易于自动化，智能化的特点。某钢铁厂煤气压缩机房一年多的使用情况证实此方法的有效性。

关键词: 声学, 隔声, 智能控制, 隔声罩