Time : 2022-09-08 Browse : 29
The noise generated by cooling towers during operation not only affects the surrounding environment, but may also cause environmental pollution. Whether it is natural ventilation or mechanical ventilation cooling towers, there are noise problems. Among them, the noise source of mechanical ventilation cooling towers is more complicated, and targeted governance needs to start from the source.
The noise of mechanical ventilation cooling towers mainly comes from four aspects:
First, aerodynamic noise, which is composed of the rotation noise and eddy noise of the fan, is mainly medium and low frequency, propagates far and is difficult to attenuate; second, water spray noise, which is the main noise of counterflow cooling towers, is related to the density of water spray and the height of water droplets falling, and is a medium and high frequency steady-state noise; third, mechanical noise, which is generated by the vibration of rotating parts such as motors and fans, and the noise intensity is related to equipment parameters; fourth, secondary noise caused by tower body vibration.
Reducing the noise of cooling towers can be implemented in three steps:
Noise source control: reduce the overall airflow resistance, optimize the component design to meet the fluid characteristics; select low-noise, low-speed fans and anti-noise blades; use one-way fans or two-speed fans for the motor, and operate at low speed at night to reduce noise; lay silencer pads in the water collection tank, and install semi-soft fillers in the rain area to reduce the sound of water droplets hitting.
Install silencer: If the source control does not meet the standard, silencers can be installed at the inlet and outlet. The outlet silencer can reduce about 20dB (A). At the same time, the process conditions need to be calculated and the design adjusted if necessary.
Directional sound insulation measures: For scenes with sensitive points in multiple directions, sound insulation boards are set to reduce noise in a directional manner.
Specific measures need to be combined with the on-site environment and environmental impact assessment requirements to ensure that the noise meets the standard without affecting the performance of the cooling tower, thereby helping to improve environmental protection performance.
