某四缸柴油发电机组NVH性能分析与优化

鞠宝明^1,2，亓宗磊^1,2，澹台金耒^1,2

1.内燃机与动力系统全国重点实验室，山东 潍坊  261061；2.潍柴动力股份有限公司，山东 潍坊  261061

摘要：为解决某四缸柴油发电机组因振动过大导致的水箱裂纹问题，通过噪声、振动、声振粗糙度（noise，vibration，harshness，NVH）试验及LMS Test.Lab进行振动测试和数据采集，分析振动过大原因，提出优化方案，并进行测试及实际应用验证。结果表明：原机组固有频率约为62 Hz，与发动机第二阶激励频率耦合，产生共振，是导致原机组振动过大的主要原因；采取优化机组结构，将水箱通过支撑横梁单独固定在机组底盘上，并在底部加装减振器等优化措施；优化后各测点的振动均符合标准要求，机组固有频率提高至85 Hz，成功避开了发动机第二阶激励频率，使机组NVH性能满足要求；优化后机组实际运行500 h，未出现水箱裂纹现象，有效解决了机组振动过大故障。

关键词：柴油发电机组；共振；固有频率；NVH

NVH performance analysis of a four-cylinder diesel generator set and its optimization

JU Baoming^1,2, QI Zonglei^1,2, TANTAI Jinlei^1,2

1. State Key Laboratory of Engine and Powertrain System, Weifang 261061, China;

2. Weichai Power Co., Ltd., Weifang 261061, China

Abstract: To address the cracking of the water tank caused by excessive vibration in a four-cylinder diesel generator set, noise, vibration, harshness (NVH) tests are conducted, vibration measurement and data collection are performed by using LMS Test.Lab. The root causes of the excessive vibration are analyzed, optimization solutions are proposed, and both experimental validation and practical application verification are carried out. The results show that the original natural frequency of the generator set is approximately 62 Hz, which couples with the engine′s second-order excitation frequency, leading to resonance and serving as the primary cause of the excessive vibration. By optimizing the structure of the generator set, specifically mounting the water tank separately on the chassis using a support beam and adding vibration dampers at the bottom, the vibration levels at all measurement points meet the required standards. The natural frequency of the set increases to 85 Hz, successfully avoiding the engine′s second-order excitation frequency, thereby ensuring that the NVH performance meets the requirements. After optimization, the generator set operates for 500 hours without any recurrence of water tank cracks, effectively resolving the excessive vibration issue.

Keywords: diesel generator set; resonance; natural frequency; NVH