Quality appraisal of noise reduction equipment

noise reduction equipment is based on the core principles of sound wave interference and sound absorption attenuation. By optimizing the sound insulation structure, damping materials and active noise reduction algorithm design, it achieves a balance between broadband noise suppression and acoustic environment comfort. It is widely used in industrial plants, rail transit, architectural acoustics, precision laboratories and other fields. In the power industry, it is used for noise control of gas turbines and transformers; in rail transit, it solves low-frequency vibration noise in viaducts and tunnels; in the construction field, it improves the acoustic quality of theaters and conference halls; in precision manufacturing scenarios, it ensures a silent environment for the production of optical instruments and microelectronics. Compared with traditional sound insulation measures, noise reduction equipment has the characteristics of wide frequency response range, large insertion loss, and lightweight structure. It is the core technical equipment of modern noise pollution control.

Zhongke Testing is a product quality appraisal service organization registered with the court. It can provide quality appraisal services for noise reduction equipment. It has a professional appraisal team and advanced instruments and equipment to provide fair and accurate appraisal results for the quality appraisal of noise reduction equipment.

As noise emission standards become stricter, there has been a significant increase in noise reduction equipment quality disputes. The judicial dispute focuses on:

1. Dispute over performance indicators: whether the measured insertion loss reaches the contracted value and whether the natural frequency matching meets the standards;

2. Material defects: insufficient density of the damping layer leads to loss of resonance suppression Effectiveness, the hydrophobicity of the sound-absorbing cotton is not up to standard, causing mildew;

3, process problems: the sealing strip of the sound insulation cover is aging and cracking, and the phase delay of the active noise reduction system exceeds the standard;

4, contract performance dispute: key components do not match the technical agreement.

Noise reduction equipment quality appraisal technical methods mainly include:

1. On-site investigation and data collection:

Survey the equipment installation environment to understand the noise source and propagation path.

collects equipment technical documents, factory inspection reports and other related information.

2. Measurement test:

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A power plant of the applicant signed a "Gas Turbine Noise Reduction System Procurement Contract" with an environmental protection company of the respondent, purchasing 2 sets of ZNQ-2000 equipment for noise control at the factory boundary. The actual measured noise reduction during acceptance was only 18dB (contract requirement ≥25dB), resulting in environmental penalties. The power plant claimed that the equipment was defective in design, and the environmental protection company argued that it was caused by deviation in the installation angle on site.

identification analysis results:

The quality analysis expert group discussed and comprehensively analyzed the relevant information of "noise reduction equipment", contract technical agreements, on-site investigation case materials and other data, and made the following quality analysis opinions: HTMLTAGTO The surface density of the composite sound insulation board of the equipment involved in KEN5

is only 12kg/m² (contract requirement ≥18kg/m²), and the low-frequency sound insulation is reduced by 40%; the loss factor of the damping layer is only 0.15 (standard ≥0.25), and the resonance peak suppression capability is insufficient; the delay time of the active noise reduction system reaches 15ms (agreement ≤8ms), resulting in the failure of reverse-phase sound wave interference.

The appraisal conclusion concluded that the environmental protection company failed to control material parameters and system algorithms according to technical protocols, and structural design and performance defects were the main reasons for the substandard noise reduction.

Noise reduction equipment quality appraisal report should include the following content:

1, entrusting unit, appraisal matters and appraisal purpose

2, basic information of the equipment, technical parameters

3, appraisal method and process

4, measurement test results and data analysis