Study On Vibration Noise Analysis And Control Technology Of The Heating Circulation Pump System

With the development of people’s life, the water pump system has become anessential part of daily life. The vibration and noise generated during the operation ofthe pump system has become a new pollution in people’s lives. As the buildingstructure tends to be simple and lightweight, the removal of vibration and noisegenerated by the system is more and more difficult to meet the requirement of people.In this paper, acoustic-structural coupling theory is mentioned and used for analyzingthe low frequency vibration and noise in actual engineering projects. Use theacoustic-structural coupling theory to solve problems in circulating pump heat-supplysystem and analyze the mutual influence between the vibration and acoustic fieldqualitatively and quantitatively. In this paper, the acoustic-structural coupling isdivided into two aspects--the effect of sound field on system vibration and effect ofvibration on the sound field. Because of the complexity of the pump pipeline system,the ensemble empirical mode decomposition based on threshold autoregressive model(E-TAR-EMD) is proposed for vibration feature extraction.First of all, influence of sound field on the vibration mode of pipeline is analyzedusing the finite element software Patran combined with Virtual lab analysis software.A water pump test-bed mimicking the actual working conditions is built. Taking thewater pump test-bed as an example, the theoretical result is conforming to theexperimental results. The theoretical and experimental show that noise has greatinfluence on the vibration mode in the pipeline and the pipeline vibration peak isskewing in frequency. For different frequencies, the additional displacement of thepipeline caused by the additional load made by sound field is quite different.Acoustic-structural coupling frequency is mainly concentrated in the300Hz frequencyband and the theory result is consistent with actual measurement. It has a guidingsignificance for improving the vibration isolation measures.Taking the actual project as the background, the influence of sound field on themode of vibration is deduced with acoustic-structural coupling finite element theoryand the influence of the floor vibration on sound field of post-floor is calculated by acoustic coupling boundary element theory. The abnormal peak problem in certainfrequency band in post-floor field is put forward and solved. The superposition offloor radiation sound and floor projection sound causes the abnormal peak and itbelongs to the acoustic-structural coupling boundary element. Use the ensembleempirical mode decomposition based on threshold autoregressive model(E-TAR-EMD) method to analyze the vibration signal and obtain the feature ofvibration. Coupling the floor projection sound with the floor vibration, sound pressurelevel nephogram in different frequency is acquired and the theoretical value meets theactual measurement. The influence of the floor vibration on the sound field near themeasure point is proved and the reason why the noise in certain frequency is difficultto be eliminated is explained.Finally, aiming at the low frequency vibration problem in actual engineeringprojects, the mathematical model is established. It shows that the isolation only usingspring is inefficient in low frequency and damping measure is needed to absorbvibration energy. Free damping measure and constrained damping measure are putforward and the energy dissipation mechanism and effect of vibration isolation areanalyzed on the microscopic level. The parametric analysis of tow measures is doneand the result meets the experimental result well. The result shows that parameter hasa huge effect in vibration isolation and constrained damping measure is more efficientthan free damping measure. This provides a new way for the damping measure and itsoptimization in the future.