Thermal Efficiency of Domestic Cooking-gas Burner Using Open-Cellular Porous Media in the Case of Varied Outlet Diameter of Mixing Tube

摘要

The domestic cooking-gas burner consumed the highest amount of Liquefied Petroleum Gas (LPG) not over 5.78 kW (≤ 280 mmH_2O) based on Thailand Industrial Standard (TIS 2312-2549) is modified by using the open-cellular porous media. The Nickel-Chrome (Ni-Cr) with pores per inch (PPI) of 8.5 and porosity (ε) of 0.92 is selected as porous media. To investigate the performance of a new cooking-gas porous burner, three outlet diameters of mixing tube (D_(out)) between primary air and LPG, i.e., 27, 35 and 43 mm., are examined. The temperatures at bottom vessel (Tv) and water (T_w) are monitored. The exhaust gas (CO and NOx) is also observed. Thermal efficiency (n) of three modified burners are estimated in accordance with TIS 2312-2549. From the experiment, the Tv is increased with Dout leading to the boiling time (t) of Tw for reaching to about 99°C (depend on TIS 2312-2549) in the case of D_(out) = 43 mm gives the fastest. The CO and NOx of all burners are not difference and are in relative low level: CO is in the range of 140 to 180 ppm and NOx is not over 70 ppm. The ηth is raised with increasing D_(out) in which yield as 47.53, 52.86 and 54.77% for D_(out) of 27, 35 and 43 mm., respectively.