Session C-19 : NVH II Manuscript Reference No. 1158 Vertical-Vibration Suppressing Design of Accumulator with New Vibration-Measuring Method Hikaru Wada Technology and Innovation Center Daikin Industries, Ltd. July 11-14, 2016
Overview 1.Issues with vibration-measuring 2.New compressor vibration-measuring method 3.Development of an accumulator with new vibration measuring method 2
Overview 1.Issues with vibration-measuring 2.New compressor vibration-measuring method 3.Development of an accumulator with new vibration measuring method 3
Overview 1.Issues with vibration-measuring 2.New compressor vibration-measuring method 3.Development of an accumulator with new vibration measuring method 4
Overview 1.Issues with vibration-measuring 2.New compressor vibration-measuring method 3.Development of an accumulator with new vibration measuring method 5
Overview 1.Issues with vibration-measuring 2.New compressor vibration-measuring method 3.Development of an accumulator with new vibration measuring method 6
1. Issues: Sound from outdoor unit Microphone Acceleration sensor Outdoor unit Compressor Figure 1: Sound and vibration measuring for an outdoor unit 7
1. Issues: Sound from outdoor unit The Accumulator vertical vibration was the cause of the noise from the outdoor unit 500 Hz band sound Vibration peak in the 500 Hz band Figure 2: Contour map of 1/3 octave band sound from the outdoor unit Figure 3: Acceleration spectrums of acceleration vertical vibration of the accumulator 8
1. Issues: conventional vibration-measuring Facility piping at the discharge side Facility piping at the suction side Main Body Accumulator Compressor Acceleration sensor Figure 4: Conventional Evaluation of vibrations of an individual compressor 9
1. Issues: conventional vibration-measuring The vertical vibration decreased in the 500 Hz band when the compressor was evaluated alone Reason: large piping mass and high support rigidity Small vibration in 500 Hz band Figure 5: Acceleration of the accumulator vertical vibration of an individual compressor 10
Overview 1.Issues with vibration-measuring 2.New compressor vibration-measuring method 3.Development of an accumulator with new vibration measuring method 11
2. New method: Vibration-measuring 1. Flexible tube 1. Flexible tube 3. Suspension wires 2. Piping weight 2. Piping weight 4. Compressor Installation weight 5. Vibration isolating rubber base Figure 6: Evaluation of vibrations of an individual compressor: New method 12
2. New method: Vibration-measuring Flexible tube: supports the compressor flexibly lower support rigidity 1. Flexible tube 3. Suspension wires 1. Flexible tube 2. Piping weight 2. Piping weight 4. Compressor Installation weight 5. Vibration isolating rubber base Figure 6: Evaluation of vibrations of an individual compressor: New method 13
2. New method: Vibration-measuring Piping weight: isolates the vibrations from the system piping 1. Flexible tube 3. Suspension wires 1. Flexible tube 2. Piping weight 2. Piping weight 4. Compressor Installation weight 5. Vibration isolating rubber base Figure 6: Evaluation of vibrations of an individual compressor: New method 14
2. New method: Vibration-measuring Suspension wire: prevents the gravity of the flexible tube 1. Flexible tube 3. Suspension wires 1. Flexible tube 2. Piping weight 2. Piping weight 4. Compressor Installation weight 5. Vibration isolating rubber base Figure 6: Evaluation of vibrations of an individual compressor: New method 15
2. New method: Vibration-measuring Compressor installation weight: prevents ground vibrations 1. Flexible tube 3. Suspension wires 1. Flexible tube 2. Piping weight 2. Piping weight 4. Compressor Installation weight 5. Vibration isolating rubber base Figure 6: Evaluation of vibrations of an individual compressor: New method 16
2. New method: Vibration-measuring Vibration-isolating rubber base: secures compressor for safety 1. Flexible tube 3. Suspension wires 1. Flexible tube 2. Piping weight 2. Piping weight 4. Compressor Installation weight 5. Vibration isolating rubber base Figure 6: Evaluation of vibrations of an individual compressor: New method 17
2. New method: Advantage The new method enabled the measurement of previously difficult-to-measure vertical vibrations of an accumulator Vibration peak in 500 Hz band Figure 7: Acceleration of the accumulator vertical vibration of an individual compressor with new method 18
Overview 1.Issues with vibration-measuring 2.New compressor vibration-measuring method 3.Development of an accumulator with new vibration measuring method 19
3. Development: Cause of vertical-vibration There were acoustic modes in the 500 Hz in the accumulator antinode node Figure 8: Acoustic eigenvalue analysis of the accumulator internal space 20
3. Development: Cause of vertical-vibration Pressure difference from top to bottom was 180 in 500 Hz The vertical vibration was caused by the pressure difference Figure 10: Accumulator vertical vibration Phase difference was 180 acceleration sensor Pressure sensor Figure 9: Measurement Point Figure 11: Pressure differences between the top and bottom 21
3. Development: Countermeasure The countermeasure part was attached to the antinode of the acoustic mode in order to prevent pressure fluctuations Countermeasure part Figure 12: Cross-sectional view of conventional accumulator Figure 13: Cross-sectional view of countermeasure accumulator 22
- 70 % 3. Development: reduced vertical-vibration The pressure fluctuations caused by the acoustic mode were reduced in the countermeasure accumulator Conventiona New Figure 14: Acoustic response analysis of the accumulator internal space 23
3. Development: reduced vertical-vibration The vertical vibration has been reduced by approximately 27 percent 19m/s 2 of vibration peak -27% 14m/s 2 of vibration peak Figure 15: Acceleration of the accumulator vertical vibration (Left: Conventional Accumulator Right: Countermeasure Accumulator) 24
Summary 1. We developed a vibration-measuring method that utilizes a flexible support, which enabled the evaluation of vertical vibration of the accumulator 2. The vertical vibration of the accumulator in the 500 Hz band was caused by the acoustic mode 3. In consideration of reduction in the acoustic mode excitation, a part that prevents pressure fluctuation was attached to the antinode of the acoustic mode 4. It was confirmed that the vertical vibrations had been reduced by approximately 27 percent with new method 25
Summary 1. We developed a vibration-measuring method that utilizes a flexible support, which enabled the evaluation of vertical vibration of the accumulator 2. The vertical vibration of the accumulator in the 500 Hz band was caused by the acoustic mode 3. In consideration of reduction in the acoustic mode excitation, a part that prevents pressure fluctuation was attached to the antinode of the acoustic mode 4. It was confirmed that the vertical vibrations had been reduced by approximately 27 percent with new method 26
Summary 1. We developed a vibration-measuring method that utilizes a flexible support, which enabled the evaluation of vertical vibration of the accumulator 2. The vertical vibration of the accumulator in the 500 Hz band was caused by the acoustic mode 3. In consideration of reduction in the acoustic mode excitation, a part that prevents pressure fluctuation was attached to the antinode of the acoustic mode 4. It was confirmed that the vertical vibrations had been reduced by approximately 27 percent with new method 27
Summary 1. We developed a vibration-measuring method that utilizes a flexible support, which enabled the evaluation of vertical vibration of the accumulator 2. The vertical vibration of the accumulator in the 500 Hz band was caused by the acoustic mode 3. In consideration of reduction in the acoustic mode excitation, a part that prevents pressure fluctuation was attached to the antinode of the acoustic mode 4. It was confirmed that the vertical vibrations had been reduced by approximately 27 percent with new method 28
Summary 1. We developed a vibration-measuring method that utilizes a flexible support, which enabled the evaluation of vertical vibration of the accumulator 2. The vertical vibration of the accumulator in the 500 Hz band was caused by the acoustic mode 3. In consideration of reduction in the acoustic mode excitation, a part that prevents pressure fluctuation was attached to the antinode of the acoustic mode 4. It was confirmed that the vertical vibrations had been reduced by approximately 27 percent with new method 29