The Journal of the Acoustical Society of Korea (한국음향학회지)

The Acoustical Society of Korea (한국음향학회)
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Analysis of noise source for refrigerant-induced noise in suction and discharge piping systems of compressor installed in air conditioner outdoor unit using wavenumber-frequency decomposition technique

파수-주파수 분리 기법을 통한 에어컨 실외기 압축기 흡배기 배관계 냉매 유발 소음원 분석

  • Sangjun Park ;
  • Sangheon Lee ;
  • Cheolung Cheong (School of Mechanical Engineering, Pusan National University) ;
  • Jinhyung Park ;
  • Jangwoo Lee
  • 박상준 (부산대학교 기계공학부) ;
  • 이상헌 (부산대학교 기계공학부) ;
  • 정철웅 (부산대학교 기계공학부) ;
  • 박진형 (LG전자 에어솔루션 연구소) ;
  • 이장우 (LG전자 에어솔루션 연구소)
  • Received : 2024.09.02
  • Accepted : 2024.09.23
  • Published : 2024.09.30
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Abstract

The supply of inverter-type air conditioners for cooling in summer and heating in winter is increasing. In addition, since the operating speed of the compressor has been continuously increased for higher efficiency and higher performance, the flow speed of the refrigerant has also increased. As a result, it results in the increase of the relative contribution of flow-born noise to total noise generated from outdoor unit, and this highlights the importance of designing for the noise reduction to addressing flow-borne noise and requires necessary to analyze noise generation mechanisms by flow borne noise. Therefore, in this paper, the noise generation mechanisms by flow borne noise from air conditioner outdoor unit was numerically investigated. The wall pressure field was predicted using Large Eddy Simulation(LES) for the refrigerant flow inside the pipe, and the vibration and radiated noise were predicted using structure and acoustic coupled scheme based Finite Element Method (FEM). In this step, the compressible/in-compressible pressure field were separated using Wavenumber-Frequency Analysis(WFA) for inner pipe wall, and this results were used in analyzing the noise source due to refrigerant flow.

여름철 냉방과 겨울철 난방을 위해 인버터형 에어컨의 보급이 증가하고 있다. 또한, 고효율 및 고성능 운전으로 압축기의 작동 속도가 지속적으로 증가해왔기에, 압축기 내부 냉매의 유속도 증가하였다. 그 결과로 실외기 소음에서 유체 유발 소음의 기여도가 상대적으로 증가하였고, 이를 저감하기 위한 저소음 설계의 중요성이 부각되며 유체 유발 소음의 발생 메커니즘 분석이 요구된다. 따라서, 본 연구에서는 에어컨 실외기 압축기 배관계 내부 냉매 유동 기인 소음의 발생 메커니즘을 수치적으로 분석하였다. 이를 위해 배관 내부의 냉매 유동에 대하여 압축성 대와류모사(Large Eddy Simulation, LES) 기법을 이용하여 배관 벽면 압력분포를 예측하였고, 유한요소법(Finite Element Method, FEM) 기반의 진동 및 소음 연성 해석을 통해 배관의 진동 및 외부 방사소음을 예측하였다. 다음으로 배관 내부 벽면 압력장에 대하여 파수-주파수 기법(Wavenumber-Frequency Analysis, WFA)을 이용하여 압축성/비압축성 압력장을 분리하고, 이를 외부 방사소음과의 비교를 통해 압축기 배관계의 냉매 유발 소음원을 정량적으로 분석하였다.

Keywords

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