Noise source analysis
(1) the noise of the cold water unit is mainly composed of the airflow noise, the motor noise, the throttle valve and the noise of the auxiliary equipment. The vibration energy of the unit is mainly caused by the unbalance of the rotating part of the centrifugal force. Motor noise, including the cooling fan noise, electromagnetic noise, mechanical noise of the bearing, mainly to fan airflow noise.
(2) the noise of pump unit mainly includes motor noise and pump noise. The vibration energy of the pump unit is mainly distributed in the vertical direction, which is generated by the unbalanced centrifugal force of the rotating part in the vertical direction component.
(3) mechanical vibration caused large noise. The water chiller and the water pump and the water pump are all rigid connections, and the cover plate is easy to be excited by the vibration. The vibration of the machine is spread around the floor, wall and the pipe network of the machine, and the solid sound is formed, and the sound of the solid is changed into the air sound, which forms the noise radiation.
Centrifuge noise is a major factor in the transmission gear and the unit exhaust (the exhaust noise of the centrifuge comes mostly from the exhaust pipe in gas flows at high speed), for the former, the three stage centrifugal can solve, for the following two methods are very effective.
1 optional compressor exhaust side coolant spray device. The device is sprayed to the exhaust side through the radial port, and the spray liquid is produced by the spray type refrigerant line sound absorption function, and the flash steam can cool the exhaust gas of the compressor.
2 adopting noise reduction pad made of sound-absorbing material, the bandage on the exhaust pipe, the general can reduce the noise of 2~4dB A.