System and method to reduce acoustic noise in screw compressors
First Claim
1. A method for attenuating noise in at least one positive displacement compressor, the method comprising the steps of:
- providing at least one compressor, the at least one compressor having a selectably controllable rotational speed;
varying the rotational speed of the at least one compressor in a random manner about a predetermined rotational speed to reduce the magnitude of the tonal acoustic noise associated with the at least one compressor; and
averaging the varied rotational speed to provide an average motor rotational speed equal to the predetermined rotational speed.
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0 Petitions
Accused Products
Abstract
A system is provided for attenuating tonal acoustic noise associated with a single positive displacement compressor, or multiple positive displacement compressors proximately located from each other. A controller selectably controls the rotational speed and the frequency of operation of each of the compressors. The controller controls the rotational speed of the compressors about a predetermined rotational speed, in a random manner, within the pre-selected speed band to reduce the magnitude of the central tonal acoustic frequency of the pressure pulsations and disperse the sound power over a wider acoustic bandwidth.
23 Citations
24 Claims
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1. A method for attenuating noise in at least one positive displacement compressor, the method comprising the steps of:
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providing at least one compressor, the at least one compressor having a selectably controllable rotational speed; varying the rotational speed of the at least one compressor in a random manner about a predetermined rotational speed to reduce the magnitude of the tonal acoustic noise associated with the at least one compressor; and averaging the varied rotational speed to provide an average motor rotational speed equal to the predetermined rotational speed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A system for attenuating noise in at least one positive displacement compressor, the system comprising:
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at least one compressor, the at least one compressor having a selectably controllable rotational speed; and a control panel comprising a microprocessor and a memory device, the control panel being configured to vary a rotational speed of the at least one compressor in a random manner about a predetermined rotational speed to reduce the magnitude of the tonal acoustic noise associated with the at least one compressor;
the average of the varied rotational speed being equal to the predetermined rotational speed. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A chiller system comprising:
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at least one refrigerant circuit, the at least one refrigerant circuit comprising at least one compressor each driven by a motor, a condenser arrangement and an evaporator arrangement connected in a closed refrigerant loop, the at least one compressor having a selectably controllable rotational speed; and a control panel comprising a microprocessor and a memory device, the control panel being configured to vary a rotational speed of each motor of the at least one compressor in a random manner about a predetermined rotational speed to reduce the magnitude of the tonal acoustic noise associated with the at least one compressor. - View Dependent Claims (18, 19, 20)
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21. A method for attenuating noise in at least one positive displacement compressor, the method comprising the steps of:
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providing at least one compressor, the at least one compressor having a selectably controllable rotational speed; and varying the rotational speed of the at least one compressor in a random manner within a predetermined range about a predetermined rotational speed to reduce the magnitude of the tonal acoustic noise associated with the at least one compressor; wherein the predetermined range is between a first predetermined percentage of the predetermined rotational speed and a second predetermined percentage of the predetermined rotational speed. - View Dependent Claims (22, 23, 24)
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Specification