小型制冷系统两相流致噪声研究进展

Progress in two-phase flow-induced noise of small scale refrigeration system

系统地回顾了制冷剂两相流致噪声研究的主要进展.两相流理论研究表明,流致噪声的根本原因是压力降随时间的变化,流型对压力降的变化有显著影响,压力降的波动会引起管道的振动和噪声.空泡动力学理论指出流型会影响气泡尺寸和形状,表现出声学特性的变化.从热力学效应、管系和节流元件结构等方面出发,阐述各因素对流致噪声的影响,综合比较两相流致噪声抑制手段的效果.从实验和数值模拟2个方面,概述了两相流致噪声研究方法的发展.展望了两相流致噪声研究的发展方向,可以通过评价噪声特性的关键指标参数,系统地考察特征参数对流致噪声的影响,提出噪声抑制措施,未来指导制冷系统的优化设计.

Progress in flow-induced noise of refrigerant was systematically reviewed.The analysis of two-phase flow theory shows that time gradient of the pressure drop is the root cause of flow-induced noise.Flow pattern significantly influences on the pressure drop,and the fluctuation of pressure drop causes vibration and noise along the pipeline.The cavitation dynamics shows that bubble size and shape change are influenced by the flow pattern,and the change of acoustic characteristics is represented.The influence of various factors on flow-induced noise was described from the aspects of thermodynamics and the structure of pipeline and throttling element.Effective methods for suppressing two-phase flow-induced noise were comprehensively compared.Researching methods of two-phase flow-induced noise were summarized from experimental and numerical simulation.Future interest will be focused on the quantitative research of flow-induced noise,and correlations will be proposed based on the characteristic parameters for the noise.Noise suppression methods will be proposed for the guideline of optimal design for refrigeration system.