Study On Decreasing Noise Of A Hermetic Reciprocating Compressor

Compressor is the main equipment of refrigerator and air-condition. With the development of ages and improvement of people living level, the requirement of the refrigerator and air-condition noise is higher. Compressor is the main source of refrigerator and air-condition noise, compressor with lower noise and higher efficiency will be of more attraction to people.Firstly, this paper make noise and vibration experiment, carry out the sound power, sound pressure level(A) and vibration of shell in three work conditions, obtain the noise and vibration spectrum. Through theory computation and analysis, the source of noise and transfer paths corresponding to every noise peak value are confirmed, the main aim to decreasing noise is pointed out.Secondly, model analysis is made on compressor shell, 13 models between 1500Hz and 5000Hz are abstained and compressor shell model is computed using a set of FEM software –MSC/NASTRAN. Make certain that noise at 2500HZ and 3150HZ are radiate noise of shell. Make optimize design on shell structure, present two ameliorate project and carry out model computation on the two project using MSC/NASTRAN to ascertain better project.It is presumed that noise at 800HZ in spectrum is inspirational noise. Thus the inspirational noise-reducer is optimized, and chooses the project of inserting one cavity. The inserting loss is computed using four-ferminal networks. The interface of computation is wrote using LabView.The inspiring sound of compressor exhaust pipe-line is tested and sound of three directions is obtained. It is ascertained that noise at 600HZ is gas pulsation noise. Exhausted reducer is modified for the noise at 2500HZ and 3150HZ. Two measures is put forward and the best measure is ascertained through computing inserting loss.The model of inspirational leaf spring valve is calculated using MSC/NASTRAN, 12 models and mode of vibration are obtained. It is ascertained that noise at 800HZ is inspirational leaf spring valve noise and sticking damping reduces noise and vibration.Sound power is measured on ameliorated compressor, the whole compressor noise reduces 1.09dB.