한국음향학회지 (The Journal of the Acoustical Society of Korea)

  • 제38권3호
  • /
  • Pages.344-351
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  • 2019
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  • 1225-4428(pISSN)
  • /
  • 2287-3775(eISSN)
한국음향학회 (The Acoustical Society of Korea)
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열변형 해석을 이용한 냉장고 수축팽창 소음저감

Reduction of contraction and expansion noise of refrigerator using thermal deformation analysis

  • 투고 : 2019.04.04
  • 심사 : 2019.05.20
  • 발행 : 2019.05.31
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초록

본 연구에서는 수축 및 팽창 소음 발생 메커니즘을 분석하고, 냉장고 운전 중에 소음발생 빈도를 줄이기 위한 효과적인 방법을 제안하였다. 냉장고의 수축팽창음 발생 시에 제품의 품질비용 상승에 영향을 주기 때문에 저감이 필요하다. 먼저, 무향실에서 측정된 음압 신호를 이용하여 주파수 스펙트럼 분석을 수행하여 소음의 특성과 발생 빈도를 분석하였다. 둘째, 열변형 해석을 수행하여 소음원의 위치를 예측했다. 분석결과에서 가장 큰 열변형은 냉동실의 왼쪽 내부 케이스의 중간에서 발생하였다. 또한 음원 위치의 가속도 레벨을 평가한 결과, 소음을 발생시키는 내부 부품이 냉동실의 세 번째 선반임을 알 수 있었다. 냉장고의 중앙 ABS(Acrylonitrile Butadiene Styrene) 두께 증가에 의한 열변형 저감을 통하여 수축팽창음을 저감할 수 있는 방법을 제안하였다.

In this work, the mechanism of contraction and expansion noise generation is investigated, and effective methods are proposed to reduce the occurrence frequency of noise during operation of the refrigerator. First, the frequency spectrum analysis was made by using the sound pressure signal measured in an anechoic chamber to investigate the characteristic of noise and the frequency of occurrence. Second, a thermal deformation analysis was conducted to predict the location of noise source. It is found from the analysis that the biggest thermal deformation occurs in the middle of the left inner case in the freezer room. Following the investigation made, a noise reduction method is proposed. The method is proposed to reduce the contraction and expansion noise by reducing the thermal deformation through increasing ABS (Acrylonitrile Butadiene Styrene) thickness in the center of refrigerator.

키워드

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Fig. 1. Generation mechanism of contraction & expansion noise.

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Fig. 2. Experimental setup of noise measurement.

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Fig. 3. Time history of sound pressure level.

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Fig. 4. Finite element model of the refrigerator.

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Fig. 5. Deformation distribution of steady state thermal analysis.

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Fig. 6. Boundary condition.

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Fig. 7. Deformation distribution of the refrigerator.

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Fig. 8. Time history of the acceleration level for contraction & expansion noise.

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Fig. 9. Maximum thermal deformations for different ABS thicknessˊ.

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Fig. 10. Mechanism for decreasing thermal deformation.

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Fig. 11. Reinforcement method for reducing thermal deformation.

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Fig. 12. Thermal deformation distribution for local ABS thickness reinforcement on the left side in F-room.

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Fig. 13. Thermal deformation distribution for local ABS thickness reinforcement on the left & right side in F-room.

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Fig. 14. Thermal deformation distribution for local ABS thickness reinforcement on the left & right side in F & R-room.

Table 1. The frequency of occurrence of contraction & expansion noise.

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Table 2. Material properties.

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Table 3. The frequency of occurrence of contraction & expansion noise without the 3rd shelf in F-room.

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Table 4. Maximum thermal deformation for ABS thickness reinforcement to different positions in the refrigerator.

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참고문헌

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