Investigation of Heat Transfer Phenomena in Blast Furnace Tuyere/Blowpipe Region

Author(s):  
Xiang Liu ◽  
Guangwu Tang ◽  
Tyamo Okosun ◽  
Armin K. Silaen ◽  
Stuart J. Street ◽  
...  

The blast furnace (BF) is a crucial stage in the iron-steel making process. Pulverized coal injection (PCI) and natural gas (NG) have been utilized in blast furnaces as a substitute fuel source for reducing coke rate. Due to introduction of injected fuels into a blast furnace, the combustion and heat transfer in the tuyere/blowpipe region affects the tuyere/blowpipe structure. A comprehensive computational fluid dynamics (CFD) model including PCI/NG combustion, multi-mode heat transfer for the blowpipe/tuyere region of a blast furnace at AK Steel Dearborn Works has been developed, considering detailed material properties in the blowpipe region. The model has been validated by comparing the blowpipe skin temperature profile with thermographic images under typical operating conditions. Based on the developed CFD model, the detailed PCI/NG co-injection combustion has been investigated and the thermal effect on the tuyere tip has been revealed.

Author(s):  
Naresh K. Selvarasu ◽  
D. Huang ◽  
Zumao Chen ◽  
Mingyan Gu ◽  
Yongfu Zhao ◽  
...  

In a blast furnace, preheated air and fuel (gas, oil or pulverized coal) are often injected into the lower part of the furnace through tuyeres, forming a raceway in which the injected fuel and some of the coke descending from the top of the furnace are combusted and gasified. The shape and size of the raceway greatly affect the combustion of, the coke and the injected fuel in the blast furnace. In this paper, a three-dimensional (3-D) computational fluid dynamics (CFD) model is developed to investigate the raceway evolution. The furnace geometry and operating conditions are based on the Mittal Steel IH7 blast furnace. The effects of Tuyere-velocity, coke particle size and burden properties are computed. It is found that the raceway depth increases with an increase in the tuyere velocity and a decrease in the coke particle size in the active coke zone. The CFD results are validated using experimental correlations and actual observations. The computational results provide useful insight into the raceway formation and the factors that influence its size and shape.


2020 ◽  
Vol 162 (A3) ◽  
Author(s):  
J J Deng ◽  
L Y Song ◽  
J Xu ◽  
B Liu ◽  
J S Lu ◽  
...  

A deep understanding of heat transfer characteristics is essential in evaluating risk and putting forward any option for the Liquefied Natural Gas (LNG) tank cooling down process. A novel Computational Fluid Dynamics (CFD) model was built to perform the flow and heat transfer simulation of the process. The predicted results agreed well with the test data from a prototype LNG tank. Then the heat transfer characteristics of the process were analysed. It was found that the vapour temperature and density were linearly varying and became stable after 2.3 hours. A sudden pressure drop risk was identified during the process, which will cause the inwards collapse risk of the invar membrane. Then the proposals to prevent the risks of the inwards collapsing membrane are presented. The heat transfer characteristics of the vapour and different membrane layers were analysed in detail, and if the suggested option was to be implemented this could save about 39% of LNG consumed.


Author(s):  
Mingyan Gu ◽  
Zumao Chen ◽  
Naresh K. Selvarasu ◽  
D. Huang ◽  
Pinakin Chaubal ◽  
...  

A three-dimensional multiphase CFD model using an Eulerian approach is developed to simulate the process of pulverized coal injection into a blast furnace. The model provides the detailed fields of fluid flow velocity, temperatures, and compositions, as well as coal mass distributions during the devolatilization and combustion of the coal. This paper focuses on coal devolatilization and combustion in the space before entering the raceway of the blast furnace. Parametric studies have been conducted to investigate the effect of coal properties and injection operations.


Author(s):  
James L Spedding ◽  
Mark Ho ◽  
Weijian Lu

Abstract The Open Pool Australian Light-water (OPAL) reactor Cold Neutron Source (CNS) is a 20 L liquid deuterium thermosiphon system which has performed consistently but will require replacement in the future. The CNS deuterium exploits neutronic heating to passively drive the thermosiphon loop and is cryogenically cooled by forced convective helium flow via a heat exchanger. In this study, a detailed computational fluid dynamics (CFD) model of the complete thermosiphon system was developed for simulation. Unlike previous studies, the simulation employed a novel polyhedral mesh technique. Results demonstrated that the polyhedral technique reduced simulation computational requirements and convergence time by an order of magnitude while predicting thermosiphon performance to within 1% accuracy when compared with prototype experiments. The simulation model was extrapolated to OPAL operating conditions and confirmed the versatility of the CFD model as an engineering design and preventative maintenance tool. Finally, simulations were performed on a proposed second-generation CNS design that increases the CNS moderator deuterium volume by 5 L, and results confirmed that the geometry maintains the thermosiphon deuterium in the liquid state and satisfies the CNS design criteria.


2007 ◽  
Vol 129 (12) ◽  
pp. 1729-1731 ◽  
Author(s):  
Yu Zhang ◽  
Rohit Deshpande ◽  
D. Huang ◽  
Pinakin Chaubal ◽  
Chenn Q. Zhou

The wear of a blast furnace hearth and the hearth inner profile are highly dependent on the liquid iron flow pattern, refractory temperatures, and temperature distributions at the hot face. In this paper, the detailed methodology is presented along with the examples of hearth inner profile predictions. A new methodology along with new algorithms is proposed to calculate the hearth erosion and its inner profile. The methodology is to estimate the hearth primary inner profile based on 1D heat transfer and to compute the hot-face temperature using the 3D CFD hearth model according to the 1D preestimated and reestimated profiles. After the hot-face temperatures are converged, the hot-face positions are refined by a new algorithm, which is based on the difference between the calculated and measured results, for the 3D computational fluid dynamics (CFD) hearth model further computations, until the calculated temperatures well agree with those measured by the thermocouples.


Author(s):  
Ramiz Kameel ◽  
Essam E. Khalil

Airflow characteristics in ventilated and air-conditioned spaces play an important role to attain comfort and hygiene conditions. This paper utilizes a 3D time-dependent Computational Fluid Dynamics (CFD) model to assess the airflow characteristics in different air-conditioned spaces. It is found that the optimum airside design system can be attained, if the airflow is directed to pass all the enclosure areas before the extraction. Still most of these factors and evaluation indices have the shortage of adequately describe the influence of the recirculation zones on the occupancy zone and also on the fresh supplied air. The model of evaluation should assess the airflow characteristics in any enclosure according to its position in the enclosure and the expected target of it along its pass to the extraction.


2015 ◽  
Vol 821-823 ◽  
pp. 452-455 ◽  
Author(s):  
Zsolt Toth Pal ◽  
Ya Fan Zhang ◽  
Ilja Belov ◽  
Hans Peter Nee ◽  
Mietek Bakowski

– Thermal contact resistances between a silver metallized SiC chip and a direct bonded copper (DBC) substrate have been measured in a heat transfer experiment. A novel experimental method to separate thermal contact resistances in multilayer heat transfer path has been demonstrated. The experimental results have been compared with analytical calculations and also with 3D computational fluid dynamics (CFD) simulation results. A simplified CFD model of the experimental setup has been validated. The results show significant pressure dependence of the thermal contact resistance but also a pressure independent part.


2018 ◽  
Vol 7 (3.7) ◽  
pp. 142 ◽  
Author(s):  
Mana Wichangarm ◽  
Anirut Matthujak ◽  
Thanarath Sriveerakul ◽  
Sedthawatt Sucharitpwatskul ◽  
Sutthisak Phongthanapanich

The objective of this paper is to numerically study the flow feature and combustion phenomena of an energy-saving cooking burner using three-dimensional computational fluid dynamics (CFD). Combustion temperatures were experimentally and numerically investigated in order to not only validate the CFD model, but also describe the combustion phenomena. From the temperature comparison, the CFD model was good agreement with the experiment, having the error of less than 5.86%. Based upon the insight from the CFD model, the high temperature of 1,286 K occurred at the middle of the burner. The high intensive vortex of the flow being enhanced the combustion intensity and the heat transfer coefficient is obvious observed near the burner head inside the ring. Therefore, it is concluded that the burner ring is the major part since it controls flame structure, high temperature region, intensive combustion region, heat loss and suitable flow feature. However, heat transfer to the vessel should be further clarified by the CFD model.   


2014 ◽  
Vol 687-691 ◽  
pp. 623-626
Author(s):  
Zhi Ren Yin ◽  
Li Jun Yang ◽  
Run Ze Duan

Numerical Simulation of pulsating flow in a pulse combustor tailpipe was performed using computational fluid dynamics (CFD) method. The flow in the pipe was characterized by periodic pulsating. The influence of this pulsating includes incomplete flow development and high level of convective heat transfer rate, and both were considered and investigated by the CFD model. Compared with the steady flow condition, results showed that the heat transfer coefficient and Nusselt number were 2.35 times higher.


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