Noise And Heat Analysis Of Small And Medium-power Diesel Generator Set

It is one main topic in the world to research on improving low noise characteristicsof the diesel generator set with no effects on heat exhaust. The main purpose of thiswork is to provide a theoretical basis for structure optimization by the analysis of thesmall and medium-power diesel generator set structure-acoustic radiation, the analysisof acoustic enclosures acoustic field and thermal field.The acoustic model and the surface acoustic field of6kw diesel generator set havebeen simulated by the boundary element method. Based on acoustic transfer vector(ATV), surface noise radiation of the diesel generator set with three different vibrationdamping pads, DX, DJ and B5, has been predicted. According to this simulation result,the panel acoustic contribution has been analyzed. Negative, positive or neutral areas ofdiesel generator set has been categorized. The structure which mainly contributed to theacoustic pressure level should be optimized.In addition, the surface acoustic pressure level of6kw silent canopy dieselgenerator set and near-field acoustic pressure of200kw Silent canopy diesel generatorset have been measured to assess the acoustic enclosure’s performance. According to thesurface acoustic pressure level experimental results, the acoustic enclosures of6kwsilent canopy diesel generator set which cannot ensure enough heat exhausted by airhave low surface acoustic pressure level. According to the near-field acoustic pressureexperimental results,200kw silent type diesel generator set’s exhaust channel which hasa high acoustic pressure should be optimized.Based on experimental data and analysis results, acoustic field inside the200kwsilent canopy diesel generator set’s exhaust channel has been analyzed by finite elementmethod. By changing the location of sound absorbing structure, the acoustic impedancevalue of sound-absorbing material and the size of exhaust export shape, inside-acousticfield of the exhaust channel was numerically simulated and the results of acousticpressure was compared. The results showed the main reasons for bad performance ofsound insulation and the relationship between acoustic enclosures structural parametersand sound insulation performance. Finally, in order to study the impacts on the air resistance which from the structuralparameters of one6kw silent canopy diesel generator set’s exhaust channel, the pressurefield and flow field of the exhaust channel was analyzed with Computational fluiddynamics (CFD) method to study the factors which affect the air resistance. Bychanging the location of the wind resistance board or the muffler, the size of exhaustexport shape, air flow in the exhaust channel was numerically simulated and the resultsof air resistance and flow field was compared. The results show that air resistance canbe reduced by moving the wind resistance board to expand the exhaust channel’svolume, adjusting the location of muffler, increasing the distance between intakes andthe U-shaped baffle or reducing the width of the metal grid can reduce air resistance;when the surface roughness of the sound-absorbing sponge isn’t considered,changingthe thickness has little effect on air resistance.