Acoustic and Energy Efficiency Analysis of Alternative Geometries of Plastic Suction Muffler

The suction muffler in a reciprocating compressor is used to attenuate sound pressure generated by vibrational noise, piston/valve movements and flowing noise. While the suction muffler directs the gas flow to the valve for compression, it also takes a critical role in damping the sound waves caused by the movement of the valve. The suction muffler in a reciprocating compressor is a reactive type silencer, therefore it absorbs the sound wave by reflecting it with geometries such as expansion chambers. However, the suction muffler adversely affects the compressor performance since it creates additional pressure drop to the system. Due to strong interdependency of components and parameters, Coefficient of Performance (COP) and noise trade-off are difficult to perform especially considering the geometric design constraints. For this reason, the most critical design objectives for hermetic reciprocating compressors are high energy efficiency and quiet operating conditions. In this study, the tesla valve, which prevents the reflow of the refrigerant gas into the suction muffler from the suction valve, is modified for the reciprocating compressor muffler to improve COP. The new designs will be optimized by considering computational fluid dynamics analysis and acoustic transmission loss analysis. The numerical results will be experimentally validated in semi-anechoic room and calorimetry test is performed with the most optimal cases. Additionally, it is expected that the tesla valve design provides energy efficiency with acoustic gain especially in 630–800 Hz band.