Diesel Generator Room and Gas Room Soundproofing and Noise Reduction Project Contracting - Design and Construction - Noise and Exhaust

I. Overview

The generator room is located in the basement of a separate building. The exhaust and intake vents of the room are situated on the side walls of the generator room, and the exhaust outlets of the units directly radiate outward. Prior to treatment, the operation of the generator room produced a loud noise of approximately 110 decibels, which inevitably polluted the surrounding environment.

II. Design Basis

"Relevant laws include the 'Environmental Protection Law of the People's Republic of China' and the 'Noise Pollution Law'."

2. Environmental Noise Standard (GB12348-1990 or GB3096-93)

3. Environmental Noise Measurement Methods (GB12349-1990)

4. Conduct on-site inspection of the pollution source overview.

5. Dimensions, specifications, and requirements provided by the user.

III. Design Principles

1. The design strives to adhere to the principle of unifying advanced technology with economic rationality, aiming to achieve reliable technology and favorable economic costs.

2. Formulate an advanced and reasonable comprehensive management plan based on the actual on-site conditions, aiming for stable treatment effects, economic costs, and no impact on the normal operation and management of equipment, as well as ease of maintenance and upkeep.

3. Design is always guided by the principle of responsibility to the user, taking into account the operating temperature of the unit, preventing losses and extending service life, to ensure the generator set operates under optimal conditions.

4. Sound Absorbing Wall: Perforated plate resonance sound absorption arrangement.

Perforated plate resonance acoustic arrangement, which works on the principle that when sound waves strike the surface of the perforated plate, most of the sound energy excites the back-and-forth motion of air within the holes. Due to the frictional resistance of the hole walls, the energy of the sound is dissipated. This arrangement is suitable for absorbing low-frequency noise.

The generator room walls are equipped with an acoustic layer, with lightweight aluminum alloy frames fixed to the walls, filled with centrifugal composite acoustic material. The acoustic coefficient is 0.8, and the density is 25 kg/m³. The protective layer is made of aluminum alloy spray-painted perforated plates, with a perforation rate of 10%. Typically, the main noise frequency in the machine room is between 100Hz and 500Hz, with the wall acoustic coefficient exceeding 0.85.

Function: Sound absorption of 6-10 dB

Sound Insulation: 20dB

Features: Attractive appearance, strong tactile feel, and a broad absorption frequency range.

Glossary Explanation:

Absorption Coefficient: The ratio of the energy absorbed by the material to the total energy incident on the material. A higher absorption coefficient indicates better sound-absorbing properties of the material.

Punching Rate: The ratio of the area of the punched holes on the perforated plate to the total area of the plate. The punching rate is typically controlled between 1-10%, and should not exceed 20% to maintain the resonance absorption effect.

Material Density: High material density can enhance low-frequency sound absorption but often degrades high-frequency absorption. Conversely, low material density can improve high-frequency absorption but typically worsens low-frequency absorption. Therefore, the selection of material density depends on specific requirements.

Effective methods for controlling and mitigating noise and combustion noise:

One: Vibration isolation is applied to the unit, typically using vibration dampers. After isolation, the vibration on the surface of the unit is effectively blocked.

2. Noise reduction is performed on the noise propagation pathways, reducing the sound source's outward radiation, and soundproofing and sound-absorbing treatments are applied to the interior walls and ceiling of the机房. This ensures that the noise source is effectively attenuated before exiting the机房, enhancing the overall noise reduction effectiveness of the room.

Cooling fan and exhaust duct noise treatment

2. Fan noise consists of rotational and vortical noise.

3. Primarily, it's about designing an effective ventilation and sound absorption channel, which can be composed of ducts and ventilation noise reduction boxes, or even sound absorption panels. Increasing the length and width of the ventilation channel parameters can enhance the sound absorption effect.

Section 3: Noise Reduction Construction Plan for Generator Sets

Based on the on-site conditions, a comprehensive construction plan is implemented, including effective sound insulation, absorption, vibration reduction, and dust removal measures, tailored to the current status of the main noise sources.

(1) Acoustic and sound absorption treatment for exhaust ducts:

1. Install primary and secondary exhaust duct silencing devices internally.

2. Install curved acoustic deflection plates at the bottom of the ventilation duct.

(2) Acoustic and Absorptive Diverter Plates for the Air Intake Channel.

1. Install and set up a secondary exhaust silencing device within the exhaust duct.

2. Install a curved sound-absorbing deflector at the bottom of the ventilation duct.

(3) Exhaust Duct Noise Reduction Measures:

1. Add sound-absorbing ceiling panels to the machinery section of the generator room within the server room, which can reduce the echo inside the room and enhance sound insulation at the same time.

2. Add sound-absorbing walls to the generator room within the server room, which can both reduce the echo inside the room and enhance sound insulation.

IV. Explanation of the reasons for intake and exhaust ventilation in the diesel generator room.

1. Air Intake System: Each diesel generator set requires a large volume of fresh air during operation, primarily for diesel combustion and electrical ball cooling.

2. Exhaust System: During the operation of the diesel engine, a large amount of heat is generated, which needs to be extracted from the engine room to ensure the room temperature does not exceed 50 degrees, providing a normal working environment for the generator set.

3. The noise reduction engineering for the server room is designed with a reasonable intake and exhaust area, referencing the scientific and technological parameters such as air demand, exhaust gas emissions, and heat dissipation requirements of the diesel generator set.