天然气预热温度对蓄热式加热炉内温度场和NO_x排放影响的研究
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摘要
为了研究不同天然气预热温度对蓄热式加热内炉温度场和NO_x排放的影响,对加热炉操作参数进行优化。采用fluent软件中标准k-ε模型、P-1辐射模型、涡耗散模型、热力型NO_x模型对不同天然气预热温度情况下加热炉内的速度场、温度场、浓度场进行数值模拟分析。结果表明:提高天然气的预热温度,减小了炉膛中心区域的流速,有利于炉膛内火焰的轴向扩散,高温区域也有变小的趋势,炉膛温度趋于均匀。随着天然气预热温度的升高,炉膛最高温度近线性增大,平均温度先减小后增大,CH_4浓度近线性降低,O_2浓度近指数型增加,NO浓度先减后增,且NO的高浓度区域分布与高温区域基本对应。
In order to study the influence of different preheating temperature of natural gas on the temperature distribution and NO_x emission in the regenerative heating furnace,optimized the operating parameters of the furnace. The study used the standard k-ε model,P-1 radiation model,eddy dissipation model and thermodynamic NO_x model in fluent software to simulate the temperature field and concentration field in the heating furnace under different natural gas preheating temperature. The results show that the increase of preheating temperature of natural gas reduces the flow rate of the central region of the furnace,and it is conducive to the radial diffusion of flame in the furnace,the tendency of the high temperature area is smaller,and the furnace temperature is nearly uniform. With the increase of the air preheating temperature of natural gas,the maximum temperature of the furnace increases linearly and the average temperature decreases and then increases,CH4 concentration decreases near linearly,O2 concentration increases near exponentially,NO concentration decrease first and then increased,and regional distribution of high concentration of NO is corresponded to high temperature region.
In order to study the influence of different preheating temperature of natural gas on the temperature distribution and NO_x emission in the regenerative heating furnace,optimized the operating parameters of the furnace. The study used the standard k-ε model,P-1 radiation model,eddy dissipation model and thermodynamic NO_x model in fluent software to simulate the temperature field and concentration field in the heating furnace under different natural gas preheating temperature. The results show that the increase of preheating temperature of natural gas reduces the flow rate of the central region of the furnace,and it is conducive to the radial diffusion of flame in the furnace,the tendency of the high temperature area is smaller,and the furnace temperature is nearly uniform. With the increase of the air preheating temperature of natural gas,the maximum temperature of the furnace increases linearly and the average temperature decreases and then increases,CH4 concentration decreases near linearly,O2 concentration increases near exponentially,NO concentration decrease first and then increased,and regional distribution of high concentration of NO is corresponded to high temperature region.
引文
[1]纪亚芳.基于PCS7的步进式加热炉燃烧控制系统设计[D].重庆:重庆大学,2009.
[2]张会强,陈兴隆,周力行等.湍流燃烧数值模拟研究的综述.力学进展,1999,29(4):567-572.
[3]王复越,李先春,马光宇等.高温烟气掺氧燃烧的数值模拟[J].冶金能源,2015,34(6):24-28.
[4]王浩,詹茂华,程寒飞等.低NOx排放高温空气燃烧技术的研究[J].冶金能源,2016,35(2):30-33.
[5]赵筱宏,付忠广,丁淇德等.燃料预热温度对燃气轮机燃烧室内NOx生成的影响[J].电工技术:理论与实践,2015,(11):229-231.
[2]张会强,陈兴隆,周力行等.湍流燃烧数值模拟研究的综述.力学进展,1999,29(4):567-572.
[3]王复越,李先春,马光宇等.高温烟气掺氧燃烧的数值模拟[J].冶金能源,2015,34(6):24-28.
[4]王浩,詹茂华,程寒飞等.低NOx排放高温空气燃烧技术的研究[J].冶金能源,2016,35(2):30-33.
[5]赵筱宏,付忠广,丁淇德等.燃料预热温度对燃气轮机燃烧室内NOx生成的影响[J].电工技术:理论与实践,2015,(11):229-231.