A Variety Of Shared Exhaust Pipe System Constructed Comparative Analysis Of The Measured Performance

This paper focuses on the study of pressure-changed type exhaust system in the multi-power source centralized exhaust system, mainly for residential kitchen exhaust produced poor and smoke down.The theoretical analysis, laboratory testing, computer simulation methods were combined together, in order to study and analyze the aerodynamic characteristics of pressure changed centralized exhaust system.Firstly,through pressure changed exhaust system for theoretical analysis and calculation.theoretical formula of pressure changed exhaust system has obtained, For later laboratory tests and numerical simulation for the theoretical basis of experimental and simulationSecondly, experimental platform of centralized exhaust system were built according to1:1in the outdoor,whose cross-sectional area can be adjusted to400*500mm.10floors of which adjust as the experimental system.choosing three different kind sizes of pressure changed board.which is respectly50mm,100mm,150mm. air volume of every user’s exhaust fan is divided into two branches of high and low. Experiment testing has done in a lot of different combinations of opening or closeing from the operation rate of10%to100%, Mainly to test the pressure and speed of branch and the pressure of main, and then select some of the test data collation, comparison, analysis.we draw the following conclusion; pressure changed type exhaust pipe system of three kinds of pressure change board’ssize,no matter exhaust fan’s volume is high-end or low-end the air volume of power user is greater than250m3/h in any conditions.which can satisfy the exhaust requirements, the volume and air pressure of the user’s exhaust fan is too large to prevent the closed users from smoke back, on the contrary will increase the burden on the system and leave the probability and other closed users increase and increase the amout of smoke down the most suitful for pressure changed exhaust system of10floors is this system whose pressure changed board’s size is50mm. the maximum of pipe static pressure is not in the first floor, but in the third to five floor, pipe internal pressure showed low-high-low. Again, these floors are the most prone to smoke down.Finally,gambit is used to model the experient system according to the system dimension, simulation parameters are set depending on the actual value.then we use a numerical simulation software called fluent to calculate,to obtain a series of Simulation data. Found with numerical simulation values the same as the measuring point with the experimental.and then compare and analyze the experiment testing and simulation data.It is obtained that Although the computer simulation values of pressure and velocity values are greater than the experimental test, but the trends are approximately the same.Experimental verify the test similarly. Finally made a small amount of computer simulation whose cross-sectional area is400*400mm,which can not satisfy the exhaust requirement.so the optimal cross-section of ten-floor pressure-changed type centralized exhaust system is400*500mm.