Diesel Generator Room & Gas Room Soundproofing & Noise Reduction Engineering Contract - Design & Construction - Noise & Exhaust Emissions

I. Overview

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

II. Design Basis

"China's Environmental Protection Law and the Noise Pollution Law"

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

3. Environmental Noise Measurement Methods (GB12349-1990)

4. Inspect the overview of the pollution source on-site.

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

Section 3: Design Principles

1. We strive to adhere to the principle of unifying advanced technology with economic rationality in design, to achieve reliable technology and favorable economic costs.

2. Develop an advanced and reasonable comprehensive treatment 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 the equipment, facilitating maintenance and upkeep.

3. Design always adheres to the principle of being responsible to the users, 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. Acoustic Wall Panels: Perforated plate resonance absorption layout.

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

Acoustic layers are installed on the walls near the generator room, with lightweight aluminum alloy frames fixed to the wall surface. They are filled with centrifugal composite acoustic material, featuring an acoustic coefficient of 0.8 and a density of 25 kg/m³. The protective layer is made of aluminum alloy electrostatic powder-coated perforated plates, with a perforation rate of 10%. Typically, the main noise frequency range in the room is 100Hz-500Hz, with the wall acoustic coefficient exceeding 0.85.

Effect: 6-10 dB sound absorption

Sound Insulation: 20 dB

Features: Attractive surface, strong overall feel, and a wide frequency range for sound absorption.

Definition:

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 ensure the resonant sound absorption effect.

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

Effective methods for controlling noise and combustion noise:

One, vibration isolation for the unit is implemented, typically using vibration dampers. After vibration isolation, the surface vibrations of the unit are effectively blocked.

Two, noise reduction is performed on the noise propagation path, reducing the radiation of the sound source to the outside. Insulation and sound-absorbing treatments are applied to the interior walls and ceiling of the machine room. This ensures that the noise source is effectively attenuated before exiting the machine room, enhancing the noise reduction effect of the room.

Cooling fan and exhaust duct noise reduction

2. Fan noise consists of rotational noise and vortex 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 it can be made up of sound absorption panels. Increasing the length and width parameters of the ventilation channel enhances the sound absorption effect.

Section 3: Noise Reduction Construction Plan for Generator Sets

Based on the on-site conditions, a comprehensive construction plan incorporating effective soundproofing, sound absorption, vibration reduction, and dust removal measures is adopted to address the current status of the main noise sources.

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

1. Install primary and secondary exhaust duct silencing devices within the ventilation duct.

2. Set a curved acoustic deflection plate at the bottom of the exhaust duct.

Acoustic and sound-absorbing deflection plates for the air intake channel.

1. Install primary and secondary exhaust duct silencers within the exhaust channel.

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

(3) Exhaust Duct Noise Abatement Measures:

1. Add an acoustic ceiling 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 reduce the echo inside the server room while also enhancing soundproofing effectiveness.

IV. Explanation of the reasons for the intake and exhaust ventilation for 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 ball cooling.

2. Exhaust System: During the operation of the diesel engine, a large amount of heat is generated, which needs to be extracted (dispelled) from the machine 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 of the server room is designed with a reasonable intake and exhaust area, referencing the air demand, exhaust emission, and heat dissipation requirements of the diesel generator set, among other scientific and technical parameters.