天然气加压富氧着火特性及反应机理研究  

Study on Ignition Characteristics and Reaction Mechanism of Pressurized Oxygen Enriched Natural Gas

作　　者：程佳 刘洋 伍自婷 杨金玲 邹春[3] CHENG Jia;LIU Yang;WU Ziting;YANG Jinling;ZOU Chun

机构地区：[1]广东佛燃科技有限公司,广东佛山528000 [2]佛燃能源集团股份有限公司,广东佛山528000 [3]华中科技大学煤燃烧国家重点实验室,湖北武汉430074

出　　处：《煤气与热力》2023年第10期V0001-V0010,共10页Gas & Heat

基　　金：国家自然科学基金“生物质掺混煤粉富氧燃烧中O_(2)/CO_(2)气氛和生物质对着火与燃烧稳定性的影响机制的实验与理论研究”(5177060405/E060403)。

摘　　要：在实验压力为02、1 MPa,当量比为05、10、20,实验温度范围1280~1645 K条件下,利用激波管测量了CH_(4)、C_(2)H_(6)和C_(3)H_(8)所组成的混合物在CO_(2)稀释下的着火延迟时间,改进的机理模型OXY-NG可以较好预测天然气混合物着火延迟时间与层流火焰速度。通过引入人工物质定量分析了CO_(2)的物理性质、化学性质对天然气混合物着火延迟时间的影响。与N_(2)相比,CO_(2)的物理性质和化学性质均抑制天然气混合物的着火,且化学性质影响强于物理性质影响。当量比05、实验温度1450 K时,随着实验压力上升,以三体反应⑧和②为主导的伴随效应的影响增强,而CO_(2)直接参与的反应(如基元反应⑨)的影响减弱。当量比05、实验压力02 MPa时,随着实验温度降低,伴随效应的影响略有增强,而CO_(2)直接参与反应的影响减弱更为明显。实验压力02 MPa、实验温度1450 K时,伴随效应的影响几乎不随当量比变化,而CO_(2)直接参与反应的影响随当量比增大而明显减弱,这是因为OH自由基浓度的降低使得基元反应⑨的抑制作用减弱。Under the conditions of the experimental pressures of 0.2 and 1 MPa,the equivalence ratios of 0.5,1.0 and 2.0,and the experimental temperature range of 1280 to 1645 K,the ignition delay time of a mixture composed of CH_(4),C_(2)H_(6),and C_(3)H_(8)under CO_(2)dilution is measured by using a shock tube.The improved mechanism model OXY-NG can better predict the ignition delay time and laminar flame velocity of natural gas mixture.The influence of the physical and chemical properties of CO_(2)on the ignition delay time of natural gas mixture is quantitatively analyzed by introducing artificial substances.Compared with N_(2),the physical and chemical properties of CO_(2)both inhibit the ignition of natural gas mixture,and the influence of chemical properties is stronger than that of physical properties.When the equivalence ratio is 0.5,and the experimental temperature is 1450 K,as the experimental pressure increases,the influence of the accompanying effects dominated by three-body reactions⑧and②increases,while the influence of the reactions directly participated by CO_(2)(such as the elementary reaction⑨)is weakened.When the equivalence ratio is 0.5,and the experimental pressure is 0.2 MPa,the influence of the accompanying effect slightly increases as the experimental temperature decreases,while the influence of the reactions directly participated by CO_(2)is weakened more obviously.When the experimental pressure is 0.2 MPa,and the experimental temperature is 1450 K,the influence of the accompanying effect hardly changes with the equivalence ratio,while the influence of the reactions directly participated by CO_(2)is significantly weakened with the increase of the equivalence ratio.This is because the decrease in the concentration of OH radicals weakens the inhibitory effect of the elementary reaction⑨.

关 键 词：天然气 加压富氧燃烧 着火延迟时间 反应动力学 CO_(2)影响 

分 类 号：TK16[动力工程及工程热物理—热能工程]