Taking the counter-current round cooling tower as an example, the basic principle of its work is: the dry and low-value air enters the cooling tower from the lower part of the cooling tower ; the high-temperature water with high saturated steam pressure is injected from the upper part from the injection pipe; the high-temperature water molecules evaporate at the water-vapor phase interface, and enter the air from the water phase, and at the same time achieve the purpose of cooling the high-temperature water.
The noise of cooling towers is mainly fan noise and falling water noise. Fan noise is the noise generated when the fan is running, mainly aerodynamic noise, including rotation noise and eddy current noise, as well as the noise of the reducer and the motor driving the fan ; the falling water noise is the cooling tower when it falls from the water spraying device. The sound of falling water generated by the impact of the body chassis and the accumulated water in the tray is related to the falling water height and the water flow per unit time, and is generally second only to the fan noise. In addition to the above-mentioned noises, there are also noises from circulating water pumps, associated motors, and pipeline radiation noise.
1. The influence range of cooling tower noise
The influence range of the cooling tower is related to its position. The cross flow and counter flow cooling tower is placed on the ground or on the roof, and the influence range is different. It mainly depends on whether there are high-rise buildings around. If the cooling tower is at the highest position, the influence position is mostly in the plane direction. If there are high-rise buildings around, the influence of the cooling tower is 360 degrees of the entire space. Therefore, the specific noise reduction measures should be considered from these two perspectives. The noise of the cooling tower is generally between 80 and 90, and the target noise value is below 50 decibels at night and 60 decibels during the day.
This prediction model is suitable for small cooling towers. According to the negative impact and countermeasures of cooling towers used for air conditioning in public buildings on the environment, this prediction model is suitable for cooling towers in civil buildings. Due to the noise impact of the cooling tower , the prediction mode is related to the size of the cooling tower and the distance between the prediction point and the cooling tower, and the delimitation of the range of different prediction modes is not very clear at present. You can consult the relevant cooling tower mode selection and range division. Tower manufacturer confirmed.
2. Equipment used for noise reduction in cooling towers
(1) Sound insulation cover
The sound insulation cover is mainly aimed at the cooling tower affected by the 360-degree full space. It is a closed cover, and the noise cannot leak out, so it cannot affect the surrounding area. The design and production of the board is very important. At the same time, the sound insulation doors and windows should be well sealed to replace ordinary doors and windows. sealing ability.
(2) Muffler accessories
It mainly includes muffler and muffler cooling tower louver. The operation of cooling tower equipment requires a certain amount of air intake. Therefore, muffler louvers should be installed on the sound insulation cover or sound barrier, facing the air inlet of the cooling tower to ensure the air volume demand and increase the air intake volume at the same time. Make sure that the noise will not leak out. The muffler can be installed directly on the cooling tower exhaust or on the sound insulation cover. This effectively resolves low-frequency noise caused by vibration.
(3) Shock Absorption Accessories
It is mainly to solve the vibration problem on the cooling tower, equipment vibration, pipeline vibration, the use of shock absorbers, elastic brackets, shock absorbers, etc.
(4) Sound barrier
It is mainly aimed at the plane influence area, isolates the counter flow cooling tower and the affected area, blocks the transmission path of the cooling tower noise, and is made of sound-absorbing and sound-insulating board, stainless steel material, high strength, good sound insulation effect, and corrosion resistance.
The cooling tower noise reduction treatment plan is to control the cooling tower noise reduction, sound absorption and sound insulation. The method can effectively solve the noise problem caused by cooling tower equipment.
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