Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2022Scopus SJRQ1Numerical evaluation of the coupled/uncoupled effectiveness of a fluid-solid-thermal multi-field model for a long-distance energy transmission pipeline
Wang, Kang; Xie, Kai; Zhang, Hui; Qiang, Yujie; Du, Yanping; Xiong, Yaxuan; Zou, Zhenwei; Zhang, Mingbao; Zhong, Liqiong; Akkurt, Nevzat
As the main component of energy transmission, long-distance energy transmission pipeline (LETP), whose safety problem is becoming more and more prominent with the development of the oil and gas transportation industry, is susceptible to the traffic loading, temperature loading, pressure loading and other loadings. In this paper, the mechanical characteristics of LETP under the interaction of temperature loading and pressure loading are investigated. Based on the theory of multi-field coupling, the mathematical model of fluid-solid-thermal coupling of fluid-filled pipelines under the combined effect of temperature and pressure loadings is established and verified. Meanwhile, an equivalent model is proposed to accurately calculate the stress of any pipeline segment in LETP. The results show that the coupling of temperature loading and the pressure loading is significantly affected by the end-side constraints of the pipelines. For strong end-side constraint, the coupling effect of temperature and pressure loadings has a significant effect on the calculated equivalent stress. The difference between the stress solution under coupling effect and decoupling effect is above 30 MPa. However, for weak end-side constraints, the error is within 10 MPa. The equivalent stress can be approximated by the decoupling solution instead of the coupling solution.
AtıfScopus15OpenAlex15
İncele - 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