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(lái)的消聲器以阻性消聲為主,功耗大,消聲效果不理想。經(jīng)仔細(xì)論證,應(yīng)用三級(jí)組合降噪技術(shù),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(duì)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(guò)對(duì)噴消聲減振腔,可將中低頻聲源的噪聲能量充分進(jìn)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(jí)隔振襯墊

(2) Two stage isolation pad

控制機(jī)械噪聲和燃燒噪聲的有效辦法是對(duì)機(jī)組進(jìn)行隔振處理。燃?xì)鈾C(jī)、發(fā)電機(jī)與鋼制底盤(pán)間裝設(shè)復(fù)合隔振減振墊,底盤(pán)與基礎(chǔ)之間亦墊上高能減振膠墊。經(jīng)過(guò)兩級(jí)隔振處理,不僅使機(jī)組的振動(dòng)被有效隔斷,而且使機(jī)組運(yùn)行更加平穩(wěn),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(fēng)道

(3) Anechoic exhaust duct

風(fēng)扇噪聲是由旋轉(zhuǎn)噪聲和渦流噪聲組成。旋轉(zhuǎn)噪聲由旋轉(zhuǎn)風(fēng)扇葉片切割空氣流產(chǎn)生周期性擾動(dòng)而引起。渦流噪聲是在旋轉(zhuǎn)葉片截面上發(fā)生邊界層分離時(shí),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(wěn)定的流動(dòng)噪聲。排風(fēng)道直接與外界相通,空氣流速很大,氣流噪聲、風(fēng)扇噪聲和機(jī)械噪聲經(jīng)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(jìn)氣道

(4) Anechoic inlet

機(jī)組工作在封閉的機(jī)房里面,從廣義上講,進(jìn)氣系統(tǒng)包括機(jī)組的進(jìn)風(fēng)通道和發(fā)動(dòng)機(jī)的進(jìn)氣系統(tǒng)。進(jìn)風(fēng)通道和排風(fēng)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(jī)組運(yùn)轉(zhuǎn)的噪聲都經(jīng)進(jìn)風(fēng)通道輻射到外面。發(fā)動(dòng)機(jī)進(jìn)氣系統(tǒng)的噪聲是由進(jìn)氣門(mén)周期性開(kāi)、閉而產(chǎn)生的壓力波動(dòng)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.