Parallel vs. Serial Noise Suppression Method for Positive Displacement (PD) Compressors Internal Combustion Engines (ICE)

摘要

Positive displacement (PD) compressors and internal combustion engines (ICEs) are major energy consumers. For example, a typical US household may have as many as 7 compressors (2 in house AC, 2 in auto AC, 1 each for refrigerator or freezer or shop compressed air, refer to Soedel-2007) and 4 ICEs (2 in auto, 1 each for lawn mower and auxiliary power generator). Both technologies generate high amplitude pulsating pressures1 (up to 180-200 dB) and fluctuating discharge flows that demand a silencer or muffler to suppress noise but leads to high energy costs: up to 5-7% shaft power for PD compressors and up to 2-5% gasoline or diesel consumption for ICEs. Growing global demand for higher efficiency and lower noise for these systems is conflicting with the governing rule of serial muffling (Daniel, 2005) employed for the past 100 years: “More Noise Reduction, More Back Pressure Losses or Use Larger Size or Multiple Mufflers”. No current technology could meet both demands simultaneously due to the limitation of the current serial noise suppression methodology.