Research On Key Technologies Of Noise Identification And Control Of Household Air Conditioner

With improvement of people’s living condition, air conditioner is becoming a necessity, followed by the noise of air conditioner. Small vibration and low noise is an important indicator of household air-conditioners when evaluating its comfort and quality. If you can achieve considerable technical advantage in household air-conditioner vibration and noise control, you will greatly enhance the competitiveness of your products. In this paper, some famous domestic air-conditioning business products as the research object, focusing on the vibration and noise performance, the main contents are as follows:Firstly, recommends the transmission of vibration and noise of the outdoor unit of household air conditioners, and introduces the basic principles of sound and vibration signal testing. Based on this theory, take a certain type of air conditioning unit as example for acoustic vibration and modal testing, excluding the fan factor, through the compressor housing vibration testing and other measures to further determine the root cause of abnormal noise generated, which provides a theoretical basis for the subsequent rectification.Secondly, for household air conditioner outdoor units, introduces the basic theory of air-conditioning sheet metal structural vibration and acoustic radiation with different sheet metal air conditioner cover sheet thickness, stiffener forms and holes location constraints and other factors in a simulated multi-inverter air conditioner operation vibration excitation frequencies and acoustic radiation performance. Simulation results show that complex ribs form on sheet metal can effectively alleviate the pressure which caused by the thinning design of complex vibration noise. Based on solving low frequency abnormal sound, optimize from two aspects piping systems and sheet metal parts outer unit.The feedback from the prototype trial results demonstrate the effectiveness of the noise control strategy.Taking a certain type of indoor unit as an example of noise feature recognition, analyses the noise distribution of the machine outlet, inlet and outlet volute. Taking into account the cost of the machine noise control, describes the control principle of active noise reduction technology and draw a single microphone and a single loudspeaker ANC control system block diagram. Then builds an ANC dynamic model, whose simulation results show that the ANC technique can generally lower than2dB noise level.