Diesel Generator Room & Gas Power Room Soundproofing and Noise Reduction Project Contracting - 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, and the exhaust outlets of the units radiate directly outward. Prior to treatment, the operation of the generator room produced approximately 110 decibels of loud noise, which inevitably caused pollution to the surrounding environment.
Section II: Design Basis
1. "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. Inspect the general overview of the pollution source on-site.
5. Dimensions, specifications, and requirements provided by the user.
Section 3: Design Principles
1. Strive to adhere to the principle of unity between advanced technology and economic rationality in design, to achieve reliable technology and favorable economic costs.
2. Formulate 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 is always guided by the principle of responsibility to the user, considering the operating temperature of the unit, preventing losses and wear-out, etc., to ensure that the generator set operates under optimal conditions.
4. Sound Absorbing Wall: Perforated plate resonance sound absorption layout.
Perforated plate resonance 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. This movement is resisted by the friction at the hole walls, dissipating the sound energy. This layout is suitable for absorbing low-frequency noise.
The generator room wall is equipped with an acoustic layer, with lightweight aluminum alloy frames securely mounted on the wall, filled with centrifugal composite acoustic material. The acoustic coefficient is 0.8, and the density is 25kg/m³. The protective layer is made of aluminum alloy electrostatically sprayed 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: 20 dB
Features: Attractive appearance, strong tactile feel, and a broad sound 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%; otherwise, it will fail to provide resonance absorption.
Material Density: High material density can improve low-frequency sound absorption, but often degrades high-frequency absorption. Conversely, low material density can enhance high-frequency absorption but usually 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 isolation, the surface vibrations of the unit are effectively blocked.
Two: Noise reduction is implemented in the noise transmission path, reducing the outward radiation from the sound source, and soundproofing and sound-absorbing treatments are done on the interior walls and ceiling of the machine room. This ensures effective attenuation of the noise source before it leaves the machine room, enhancing the noise reduction effect of the room.
Cooling fan and exhaust channel noise reduction
2. Fan noise consists of rotational noise and vortex noise.
3. The primary focus is on designing an effective ventilation and sound absorption channel, which can be composed of ducts and ventilation noise reduction boxes, or sound-absorbing panels. Increasing the length and width parameters of the ventilation channel enhances the sound absorption effect.
Section 3: Generator Set Noise Reduction Construction Plan
Based on the on-site conditions, an effective comprehensive construction plan is adopted, targeting the current status of its main noise sources, which includes soundproofing, sound absorption, vibration reduction, and dust removal.
(1) Acoustic and Absorptive Treatment of Exhaust Ducts:
1. Install and set up a secondary exhaust noise reduction device within the ventilation duct.
2. Install curved acoustic deflection plates at the bottom of the ventilation duct.
(2) Acoustic and absorbent deflection plates for the air intake channel.
1. Install a secondary exhaust noise reduction device inside the exhaust duct.
2. Install curved acoustic deflection plates at the bottom of the ventilation duct.
(3) Exhaust Duct Noise Reduction Measures:
1. Add an acoustic suspended ceiling in the machinery section of the generator room within the server room, which can reduce the reverberation inside the room while enhancing sound insulation.
2. Add acoustic wall panels in the generator room within the machine room to reduce the echo inside and enhance soundproofing.
IV. Explanation of the reasons for intake and exhaust ventilation in a diesel generator room.
1. Intake System: Each diesel generator set requires a substantial amount of fresh air during operation, primarily for diesel combustion and electric ball cooling.
2. Exhaust System: During the operation of the diesel engine, a large amount of heat is generated, which needs to be extracted (exhausted) from the machine room to ensure that the room temperature does not exceed 50 degrees Celsius, 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 technical parameters such as air demand, exhaust emissions, and heat dissipation requirements of the diesel generator set.
