Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2022Scopus SJRQ1Heat and mass transfer mechanism and control strategy of clean low carbon combustion technology in the novel-type coke oven flue with MILD combustion
Xu, Qian; Shen, Meng; Xie, Kai; Zhang, Hui; Akkurt, Nevzat; Wang, Jiulong; Xiong, Yaxuan; Shi, Kejian; Chen, Xingli; Lv, Qian
In the field of emission reduction, considering the limitations of single clean combustion technology and joint control of carbon emission, the application of Technology of Mixed-Gas (TMG), Technology of Low-calorific Value Gas (TLVG) and Technology of Low Oxygen Combustion (TLOC) in the Novel-type Coke Oven Flue with MILD Combustion (MILD-NCOF) was realized. By adjusting the ratio of coke oven gas to blast furnace gas (α), the ratio of flue gas to gas (β) and the ratio of flue gas to air (γ), the heat and mass transfer mechanism of combustion process in MILD-NCOF was researched, the dual emission control system and the regulation strategy of pollutant and carbon emissions were established. The results showed that with the increase of α, β and γ, the fluidity of gas and the reaction rate of combustible components in the fire path were improved, the heat and mass transfer was enhanced, and the effect of dual emission reduction of pollutants and carbon emissions was improved. When the mixing ratio α was 0.6, Tave was reached at 1594.93 K. The NOx concentration at the outlet was 116.34 mg/m3, and the sum of the molar concentrations of CO and CO2 at the outlet was reduced to 1.440 × 10−1. When the mixing ratio β was 2.4, Tave was reached at 1518.73 K, the NOx concentration at the outlet was 128.42 mg/m3, and the sum of the molar concentrations of CO and CO2 at the outlet was 1.127 × 10−1. When the mixing ratio γ was 0.6, Tave was reached at 1627.28 K, the NOx concentration at the outlet was 142.73 mg/m3, and the sum of the molar concentrations of CO and CO2 was reduced to 1.128 × 10−1, which could meet the dual standards of clean production and low-carbon environmental protection of MILD-NCOF.
AtıfScopus30OpenAlex36
İncele - MakaleYalnız künye2021Scopus SJRQ2Effect of the Mixing Structure Parameters of a Self-reflux Burner on Combustion Characteristics and NOx Emission
Xu, Qian; Shen, Meng; Shi, Kejian; Liu, Zhihui; Akkurt, Nevzat; Xiong, Yaxuan; Liu, Lin; Feng, Junxiao; Wang, Jiulong
To solve the problem of low efficiency of NOx emission reduction in self-reflux burners, this study is based on the concept of coordinated control of self-reflux burner structural and thermal parameters. After completing the structural design and optimization of thermal parameters, we continue to adjust the two key structural parameters: the nozzle axis distance and the length of the cylindrical section, to minimize NOx emissions. These are the two parameters that chiefly affect the mixing of flue gas and fuel gas. The results show that increasing nozzle axis distance can delay the mixing of gas and air and create a more uniform oxygen concentration field for the combustion process. The maximum combustion temperature is reduced from 1973.65 K to 1935.88 K and the volume fraction of NOx in the flue gas is reduced from 188.08×10−6 to 143.47×10−6. However, compared with the nozzle axis distance, the length of the cylindrical section of the burner has little effect on the mixing of the flow field. Under different cylindrical section lengths, the maximum combustion temperature does not change more than 3 K, and the volume fraction of NOx in the flue gas changes within 5×10−6.
AtıfScopus3OpenAlex2İncele - MakaleYalnız künye2021Scopus SJRQ2Effects of Optimized Operating Parameters on Combustion Characteristics and NOx Emissions of a Burner based on Orthogonal Analysis
Xu, Qian; Akkurt, Nevzat; Yang, Gang; Zhu, Lidong; Shi, Kejian; Wang, Kang; Zou, Zhenwei; Liu, Zhihui; Wang, Jiulong; Du, Zhiwei
To optimize the structure of the burner, improve the combustion performance, and reduce the emission of NOx, a self-circulating low NOx combustion technology was used to design a new type of flue gas self-circulating low NOx burner. Based on previous research on the numerical model of combustion and the composition of mixed gas on combustion and NOx emissions, the effect of various factors on the ejection coefficient of the flue gas self-circulating structure was analyzed using the orthogonal test method, and the burner operating parameters, such as preheating temperature and excess air coefficient, were deeply studied through the three-dimensional finite element numerical model in this paper. The results show that the diameter ratio of the nozzle and the length of the cylindrical section of the flue gas self-circulating structure have great influence on its ejection and mixing ability. The optimal ejection coefficient was 0.4829. Overall, the amount of NOx emissions greatly increased from 6.23×10−6 (volume fraction) at the preheating temperature 973 K to 3.5×10−3 at preheating temperature 1573 K. When the excess air coefficient decreased from 1.2 to 1, the maximum combustion temperature decreased from 2036.3 K to 1954.22 K, and the NOx emissions decreased from 352.29×10−6 to 159.73×10−6.
AtıfScopus7OpenAlex8İncele - MakaleYalnız künye2021Scopus SJRQ1A new type of two-supply, one-return, triple pipe-structured heat loss model based on a low temperature district heating system
Xu, Qian; Wang, Kang; Zou, Zhenwei; Zhong, Liqiong; Akkurt, Nevzat; Feng, Junxiao; Xiong, Yaxuan; Han, Jingxiao; Wang, Jiulong; Du, Yanping
Based on the design concept of a fourth-generation smart pipe network system, this paper innovatively proposes a new TOTS (Two-supply/One-return, triple pipe structure) arrangement method for district heating systems. Moreover, to accurately predict the heat loss due to the pipeline operation of the multi-pipe system, based on the multipole calculation method, a new heat loss theoretical analytical model for the TOTS was created; additionally, a corresponding three-dimensional numerical simulation model was established, which was analyzed and numerically solved. The results showed that in comparison with thermal loss data measured by Danfoss et al., the above analytical and numerical models have a high accuracy, and the deviation is within 2%. Additionally, through calculations, it was found that the distance between the heating pipes is an important factor that affects the total heat loss from the new multi-control heating system and the actual heat exchange between pipes.
AtıfScopus74OpenAlex75İncele