双级全预混燃气灶引射器的理论分析

Theoretical analysis on the double-stage fully premix gas stove ejector

提出的一种双级全预混引射器是燃气灶实现全预混燃烧的重要部件。以燃烧功率为3. 5kW的民用天然气燃气灶为例,建立了双级引射器的理论模型,分析了引射比、截面比、引射压差等对引射器性能的影响。结果显示:引射器存在一最佳截面比使被引射流体压差最高,最佳截面比随引射比的增加而增大,且不受引射压差的影响;被引射流体压差随引射器截面比的增大呈先快速增加后小幅下降的趋势,且受引射比和截面比的影响逐渐减弱。一、二级引射比分别为μ_1=1. 2、μ_2=9. 3时,双级全预混燃气灶引射器的最佳截面比为k_1=15、k_2=130,此时的引射器性能较好,结构较优。

It proposes double-stage fully premix gas stove ejector, which is an important part of commercial or civil gas stove to achieve full premix combustion. Taking the 3.5 kW civil stove as an example, it builds the model of the double-stage ejector, analyzes the effects of entrainment ratio, section ratio and entrainment pressure difference on the performance of ejector. Results show that the ejector has an optimal section ratio, makes the pressure different with the high entrained fluid; its value increases with the entrainment ratio, which is not influenced with the entrainment pressure difference. The pressure different of the entrained fluid with the increase of section ratio are increased rapidly at first and then slightly decreased, and the effects of entrainment ratio and section ratio is weaken. When the one or two stage entrainment ratio is μ 1=1.2, μ 2=9.3, the optimal section ratio of double-stage fully premix gas stove ejector is k 1= 15 and k 2= 130. In this case, the performance and the structure of the ejector is better.