Based on the working principle of gas generator set, it is difficult to use the method of reducing the noise source to eliminate noise, so the main thing is to effectively block its noise transmission path. The core of noise elimination technology is to use the law of natural attenuation of sound wave in propagation to reduce the pollution surface of noise. There are several ways to reduce noise: sound absorption, sound insulation and changing the direction of noise transmission. In practical engineering application, only one of them is often used. In this paper, a new combined noise reduction technology for gas generator set is proposed by using three methods.

(1)組合消聲器

(1) Combined muffler

原來的消聲器以阻性消聲為主,功耗大,消聲效果不理想。經仔細論證,應用三級組合降噪技術,將消聲器改造為新型組合式消聲器。該組合式消聲器的主要組成部件有對噴消聲減振腔、多孔式消聲罩及吸聲隔熱層和吸聲共振板等。聲源通過對噴消聲減振腔,可將中低頻聲源的噪聲能量充分進行抗性耗散。

The original muffler is mainly resistive noise elimination, which consumes a lot of power, and the noise elimination effect is not ideal. After careful demonstration, the three-stage combined noise reduction technology is applied to transform the muffler into a new type of combined muffler. The main components of the combined muffler are the opposite jet anechoic cavity, the porous anechoic cover, the sound-absorbing insulation layer and the sound-absorbing resonance plate. The noise energy of the medium and low frequency sound source can be fully dissipated by the counter jet anechoic cavity.

(2)兩級隔振襯墊

(2) Two stage isolation pad

控制機械噪聲和燃燒噪聲的有效辦法是對機組進行隔振處理。燃氣機、發電機與鋼制底盤間裝設復合隔振減振墊,底盤與基礎之間亦墊上高能減振膠墊。經過兩級隔振處理,不僅使機組的振動被有效隔斷,而且使機組運行更加平穩,整體噪聲顯著降低。

The effective way to control the mechanical noise and combustion noise is to isolate the vibration of the unit. A composite vibration isolation pad is installed between the gas engine, generator and steel chassis, and a high-energy vibration damping rubber pad is also installed between the chassis and the foundation. After two-stage vibration isolation treatment, not only the vibration of the unit is effectively isolated, but also the operation of the unit is more stable, and the overall noise is significantly reduced.

(3)消聲排風道

(3) Anechoic exhaust duct

風扇噪聲是由旋轉噪聲和渦流噪聲組成。旋轉噪聲由旋轉風扇葉片切割空氣流產生周期性擾動而引起。渦流噪聲是在旋轉葉片截面上發生邊界層分離時,氣體滑脫或分裂而成的一系列的漩渦流,從而輻射出一種非穩定的流動噪聲。排風道直接與外界相通,空氣流速很大,氣流噪聲、風扇噪聲和機械噪聲經此通道輻射出去。

Fan noise is composed of rotating noise and eddy noise. The rotating noise is caused by the periodic disturbance of the cutting air flow of the rotating fan blade. Vortex noise is a series of vortex flow formed by gas slippage or splitting when boundary layer separation occurs on the rotating blade section, which radiates an unsteady flow noise. The exhaust duct is directly connected with the outside world, the air velocity is very large, and the airflow noise, fan noise and mechanical noise radiate out through this channel.

(4)消聲進氣道

(4) Anechoic inlet

機組工作在封閉的機房里面,從廣義上講,進氣系統包括機組的進風通道和發動機的進氣系統。進風通道和排風通道一樣直接與外界相通,空氣的流速很大,氣流的噪聲和機組運轉的噪聲都經進風通道輻射到外面。發動機進氣系統的噪聲是由進氣門周期性開、閉而產生的壓力波動所形成,其噪聲頻率一般處于500Hz以下的低頻范圍。

The unit works in a closed machine room. In a broad sense, the air inlet system includes the air inlet channel of the unit and the air inlet system of the engine. The air inlet channel and the exhaust channel are directly connected with the outside world, the air flow rate is very large, and the noise of air flow and unit operation radiates to the outside through the air inlet channel. The noise of the engine intake system is caused by the pressure fluctuation caused by the periodic opening and closing of the intake valve, and its noise frequency is generally in the low frequency range below 500Hz.