بررسي تجربي و شبيه سازي سه بعدي عملكرد مشعل اجاق گاز خانگي

چكيده انگليسي :

116 Experimental investigation and three dimensional simulation of the performance of domestic stoves Mostafa Mohammadi mm mohamadi@me iut ac ir November 13 2615 Department of Mechanical Engineering Isfahan University of Technology Isfahan 94156 93111 Iran Degree M Sc Language FarsiSupervisor Mahmud Ashrafizaadeh mahmud@cc iut ac irAbstract Most of the burners used in domestic gas stoves have a simple geometry and they are usually verysimilar in design As a results newer and different burner styles are rarely seen even in newer stoves Therefore in the present study the effects of burner geometry on the thermal efficiency of gas stoves areinvestigated Although there have been numerous experimental studies to determine the thermal efficiency ofexisting burners and the effects of different parameters to improve their thermal efficiency have been studied there is still room to develop and study the performance of newer and different gas burner designs usingcomputational techniques In the present thesis first two of the most common burner designs have beenexperimentally studied according to the VITA standard and their thermal efficiencies are measured Thenthese burners are numerically modelled and their steady state performances are simulated It is then shownthat both experimental and numerical results are in a good agreement After setting up our computationalmodel the performance of some 7 new burner designs for domestic stoves are numerically modelled andstudied These burner designs have been categorized in three groups 1 simple burners 2 burners withinclined surfaces and 3 special design burners In the first group commonly used burners exist with adifference in the shape of their gas outlet holes The second group includes burners which have burner holeson two outer and inner inclined surfaces The third group includes some newer and different burner designs After numerically simulating the performance of these burners contours of temperature and flow velocity areplotted and their thermal efficiencies are determined Results show that using rectangular burner holes andinclined inner and outer surfaces on a burner would improve the burner thermal efficiency The reason forthis improvement is explained by looking at the temperature distribution at the bottom of the container whichis heated by the burner It appears that the movement of the maximum temperature towards the center of thebottom of the container improves the thermal efficiency At the and the effect of two parameters namely thegas flow rate and the height of the container above the burner are numerically studied and optimum valuesfor these parameters are determined Our numerical results show that the use of computational methods is auseful tool to study the performance of gas burners and improve their designs Keywords domestic stove burner empirical research computational fluid dynamics thermalefficiency combustion burner geometry

محمدي، مصطفي

بررسي تجربي و شبيه سازي سه بعدي عملكرد مشعل اجاق گاز خانگي

ديناميك سيالات محاسباتي , بازده حرارتي , احتراق , هندسه مشعل