Study On The Influence And Control Strategy Of Toilet Drainage Noise In Residential Building

With the proposal and development of concepts such as green buildings and healthy buildings,people’s requirements for the quality of the living environment are constantly improving.The indoor acoustic environment has become an important part of evaluating the quality of residences.The internal noise of the house directly affects people’s quality of life and work efficiency.The toilet drainage pipe is close to the bedroom,living room and other spaces,which brings obvious noise impact during the use process and is one of the main noise sources in the room.At present,the relevant researches mainly focus on the analysis of the generation principle and noise characteristics of residential toilet drainage noise.Researchers are more inclined to study the nature of the noise source itself,while relatively few studies on the distribution of drainage noise in indoor spaces.In addition,previous research often used the data obtained from actual measurement as the analysis basis,and it was necessary to establish a special laboratory for drainage noise,which would significantly increase the research cost.In this thesis,numerical simulation method is used to study the characteristics of indoor drainage noise sources and their distribution in space,and the results of numerical analysis of fluids are used as sound source data for acoustic simulation.This prediction method using acoustic finite element simulation can intuitively express the distribution characteristics of noise in the living space.Firstly,through case study,the thesis analyzes the plane layout,enclosure components,toilet drainage system and the generation mechanism and influence factors of drainage noise in typical residential buildings.At the same time,the drainage noise in typical houses is measured to understand the impact of the drainage noise of the toilet on the adjacent floors.In literature analysis and field research,it is found that there are phenomena of high drainage noise and sound pressure levels exceeding the specification requirements in ordinary residences,which seriously interfere with the normal life and rest of the residents.It is still necessary to conduct in-depth research and analysis in this field and to control indoor drainage noise.Secondly,based on the previous research and related theoretical research,a method to simulate the noise distribution in space by co-simulation of flow field and sound field was proposed by using CFD and finite element simulation analysis technology.In this study,the basic model of the toilet drainage pipes and the master bedroom suite was established to simulate the radiated sound field generated by the drainage pipes under different working conditions.The influence of pipe material,envelope component,riser position and door position on sound field distribution was analyzed by using control variable method.The results show that the noise generated by drainage pipes increases with the increase of frequency and has obvious high frequency characteristics,and the large value of SPL usually appears in the high frequency range of 1600～2000Hz.Pipes with high density and Young’s modulus,such as cast iron pipes,can reduce the impact and vibration of water flow,thereby reducing the radiated noise in the external space.When the partition wall is made of ordinary concrete brick,ordinary sintered brick,light aggregate concrete block and fly ash block,the noise values of external space monitoring points are 46.1dB（A）,44.6dB（A）,48.1dB（A）and 46.7dB（A）.Partition walls built with heavy materials such as ordinary sintered bricks and concrete bricks have good sound insulation performance,which is conducive to reducing the noise value of adjacent spaces.Partition walls made of highquality materials such as ordinary sintered bricks and concrete bricks have better sound insulation performance,which is beneficial to reduce the noise value of adjacent spaces.In addition,the relative position of the riser and the toilet door will also affect the noise level of the adjacent space.It is advisable to arrange the drain riser on the side away from the bedroom space,and avoid the toilet door directly facing the main space of bedroom.Based on the sound field simulation data and the principle of noise prevention,the control strategies for the drainage noise of residential toilets are summarized.The sound insulation effect of common toilet doors is simulated,and the results show that the high-frequency sound insulation effect of wood and glass doors is much higher than that of PVC folding doors.A simple experimental platform was set up in the semi-anechoic room to measure the sound insulation effect of pipe noise reduction materials commonly used in the market.The experimental results show that: The sound insulation range of the selected material is4.6dB（A）～7dB（A）when coated with single-layer noise isolation material,and8.3dB（A）～10.7dB（A）when combined with damping vibration isolation plate.The polyester fiber has the best noise reduction effect when used in combination with damping isolators.Therefore,measures to reduce the impact of drainage noise are proposed from the aspects of reasonably setting plane layout,controlling noise sources and controlling propagation paths.Finally,the noise reduction measures obtained in this thesis are applied to solve practical problems,and their feasibility and effectiveness are verified through actual reconstruction projects.Using finite element numerical simulation technology,this study analyzes the impact of residential toilet drainage noise on the indoor acoustic environment,and proposes corresponding design and improvement strategies.It provides corresponding reference and design basis for creating a comfortable indoor environment and reducing the interference of drainage noise,and has certain theoretical and practical significance for the design and research of healthy residential buildings.