scholarly journals Experimental Investigate on Pre-combustion Characteristic and Flame Shape of an Adjustable Axial Swirl Burner for Pulverized Coal Combustion

2020 ◽  
Author(s):  
Pengzhong Liu ◽  
Fang Niu ◽  
Pengtao Wang ◽  
Nan Jia ◽  
Jianming Zhou ◽  
...  
Keyword(s):  
High Temperature ◽  
Combustion Chamber ◽  
Flame Length ◽  
Pulverized Coal ◽  
Nox Emission ◽  
Maximum Temperature ◽  
Combustion Characteristic ◽  
Swirl Burner ◽  
Co Concentration ◽  
Flame Shape

Abstract The 14 MW pilot–scale pulverized coal experiment system was built, pre-combustion characteristic and flame shape of adjustable axial swirl burner was investigation, and influence of swirl number also was discussed. The temperature and species concentration distribution in pre-combustion chamber showed that a high temperature oxygen-free and high CO concentration zone appeared around central pulverized coal, which enhanced burnout and inhibiting or reduction NOx. The pre-combustion characteristic belonged to high temperature preheating combustion technology. The captured flame image showed that flame shape beyond pre-combustion chamber outlet belonged to turbulent diffusion flame. Then flame shape scales were obtained. For different swirl numbers, ignition, wall temperature, mean maximum temperature, oxygen-free boundary and CO concentration was discussed, the results indicated that S=1.67 had advantaged for burnout and reduction NOx emission on the basis of stable ignition and avoiding high temperature corrosion. Mean flame length and diameter and divergence angle also were analyzed, the results showed that S=1.67 case had moderate flame length and best diameter and divergence. It was favorable for flame stability and high temperature region in furnace part, and increasing burnout and deceasing NOx emission. Therefor the optimal selection was S=1.67 case under experimental condition.

scholarly journals Influence of the Inner and Outer Secondary Air Ratios on the Combustion Characteristic and Flame Shape of a Swirl Burner with a Prechamber

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Pengzhong Liu ◽  
Fang Niu ◽  
Xuewen Wang ◽  
Fei Guo ◽  
Wei Luo ◽  
...  
Keyword(s):  
High Speed ◽  
Combustion Efficiency ◽  
Flame Length ◽  
Combustion Characteristic ◽  
Swirl Burner ◽  
Free Zone ◽  
Combustion Experiment ◽  
Flame Shape ◽  
Secondary Air ◽  
Low Nitrogen

The swirl burner with a prechamber was used in a 14 MW pulverized-coal combustion experiment to investigate the influence of inner and secondary air ratios (ISA/OSA) on the combustion characteristic and flame shape in this work. The temperatures and species concentrations in the prechamber were measured via the flue gas analyzer and thermocouples. The flame shape beyond the prechamber outlet was captured by using a high-speed camera. The results showed that the combustion efficiency was increased and low nitrogen combustion was achieved by adopting the swirl burner with a prechamber. The high temperature corrosion and slagging phenomenon did not occur in the prechamber. The influence of ISA/OSA on temperature and species concentration profiles at different areas in the prechamber was different. The flame shape size exhibited an inflection point with increasing ISA/OSA. Considering, comprehensively, the temperature peak, near wall temperature, oxygen-free zone, CO concentration, flame length, flame diameter, and divergence angle, the case of ISA/OSA =1 : 2 had great processing on combustion efficiency and NOx emission. Thus, ISA/OSA = 1 : 2 was selected as the optimized case under experiment conditions.

Numerical Study on High Temperature Air Combustion in U-Type Tube

2008 ◽  
Author(s):  
Xing Li ◽  
Li Jia ◽  
Tiantian Zhang ◽  
Lixin Yang
Keyword(s):  
High Temperature ◽  
Natural Gas ◽  
Combustion Chamber ◽  
Numerical Study ◽  
Maximum Temperature ◽  
No Emission ◽  
High Temperature Air Combustion ◽  
Average Temperature ◽  
Combustion Technology ◽  
Type Tube

In this paper, the combustion characteristics of natural gas with high-temperature air combustion technology in a U-type combustion chamber were investigated by the numerical method. The results of the CFD-based mathematical modeling of rated condition were compared with experimental data including the maximum temperature, average temperature and NO emission. The research indicates that the combustion can be well simulated using the suggested numerical model. The temperature distribution, velocity distribution in the combustion chamber and NO emission were attained. In addition, the effects of some parameters such as oxygen concentration, excessive air ratio and combustion air temperature were discussed in detail. It provided primarily theoretic basis for further study of natural gas high temperature air combustion.

The ultra-low NOx emission characteristics of pulverized coal combustion after high temperature preheating

Fuel ◽  
2020 ◽  
Vol 277 ◽  
pp. 118050 ◽  
Author(s):  
Yi Zhang ◽  
Jianguo Zhu ◽  
Qinggang Lyu ◽  
Jingzhang Liu ◽  
Fei Pan ◽  
...  
Keyword(s):  
High Temperature ◽  
Coal Combustion ◽  
Pulverized Coal ◽  
Nox Emission ◽  
Emission Characteristics ◽  
Pulverized Coal Combustion ◽  
Low Nox Emission

Modeling and Experiment on Combustion Characteristics for Biomass Rotary Burner

2020 ◽  
Vol 04 ◽  
Author(s):  
Guohai Jia ◽  
Lijun Li ◽  
Li Dai ◽  
Zicheng Gao ◽  
Jiping Li
Keyword(s):  
Combustion Chamber ◽  
Combustion Temperature ◽  
Combustion Efficiency ◽  
Middle Part ◽  
Combustion Characteristics ◽  
Maximum Temperature ◽  
Excess Air ◽  
Element Simulation ◽  
Excess Air Coefficient ◽  
Secondary Air

Background: A biomass pellet rotary burner was chosen as the research object in order to study the influence of excess air coefficient on the combustion efficiency. The finite element simulation model of biomass rotary burner was established. Methods: The computational fluid dynamics software was applied to simulate the combustion characteristics of biomass rotary burner in steady condition and the effects of excess air ratio on pressure field, velocity field and temperature field was analyzed. Results: The results show that the flow velocity inside the burner gradually increases with the increase of inlet velocity and the maximum combustion temperature is also appeared in the middle part of the combustion chamber. Conclusion: When the excess air coefficient is 1.0 with the secondary air outlet velocity of 4.16 m/s, the maximum temperature of the rotary combustion chamber is 2730K with the secondary air outlet velocity of 6.66 m/s. When the excess air ratio is 1.6, the maximum temperature of the rotary combustion chamber is 2410K. When the air ratio is 2.4, the maximum temperature of the rotary combustion chamber is 2340K with the secondary air outlet velocity of 9.99 m/s. The best excess air coefficient is 1.0. The experimental value of combustion temperature of biomass rotary burner is in good agreement with the simulation results.

NOx emission from high-temperature air/methane counterflow diffusion flame

2002 ◽  
Vol 41 (7) ◽  
pp. 693-698 ◽  
Author(s):  
Ryugo Fuse ◽  
Hideaki Kobayashi ◽  
Yiguang Ju ◽  
Kaoru Maruta ◽  
Takashi Niioka
Keyword(s):  
High Temperature ◽  
Diffusion Flame ◽  
Nox Emission ◽  
Counterflow Diffusion Flame

Experimental Study on Carbonization of Low-Rank Pulverized Coal with High Temperature Heat Pipe

2014 ◽  
Vol 953-954 ◽  
pp. 1035-1039
Author(s):  
Li Qun Wang ◽  
Zhong Bo Yi ◽  
Zhong Xiang Wei
Keyword(s):  
High Temperature ◽  
Heat Pipe ◽  
Pulverized Coal ◽  
Holding Time ◽  
Raw Material ◽  
Low Rank ◽  
Experimental Result ◽  
Operating Characteristics ◽  
Temperature Heat ◽  
High Temperature Heat Pipe

Aimed at improving the utilization of pulverized coal, high-temperature heat pipe technology was introduced into lignite carbonization.Under the design of power of 10kw semi-industrial pulverized coal carbonization test equipment, Fugu lignite coal as raw material to investigate the operating characteristics of the device and carbonization characteristics. Experimental result shows that the high temperature heat pipes heat steadily and meet the temperature requirement of low-temperature carbonization. With the extension of the holding time, the semi-coke fixed carbon content increasing, but volatile matter vice versa, however, holding time above 60 minutes, the effect of carbonization is not obvious, and the best carbonization time is 30 ~ 60 minutes. The length of the holding time has little effect on gas composition, the content of H2 and CH4 are relatively higher than the rest gas, (H2 + CH4) gas accounted for 70% of the total, the heating value remains at 18.76 ~ 19.22MJ/m3, belongs to medium-high value gas, could provide for industrial and civilian use.

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