scholarly journals INFLUENCE OF THE METHOD OF NATURAL GAS SUPPLYING ON GAS DYNAMICS AND HEAT TRANSFER IN AIR TUYERE OF BLAST FURNACE

2018 ◽  
Vol 61 (5) ◽  
pp. 357-363 ◽  
Author(s):  
I. A. Levitskii ◽  
A. G. Radyuk ◽  
A. E. Titlyanov ◽  
T. Yu. Sidorova
2020 ◽  
pp. 2-7
Author(s):  
V.N. Titov ◽  
◽  
A.E. Titliyanov ◽  
I.A. Levitsky ◽  
A.I. Ternovikh ◽  
...  

Ansys Fluent 18.2 software was used to simulate PAO NLMK air tuyere functioning. It was established that 5 degrees hot air feed angle and 22 mm inner nipple diameter for natural gas feeding are rational. It was recom-mended to increase coal dust fuel feed angle till 20 degrees, to decrease dis-tance between natural gas nipple and flange till 30 mm.


Author(s):  
N. A. Spirin ◽  
O. P. Onorin ◽  
A. S. Istomin ◽  
I. A. Gurin

A blast furnace is a complicated metallurgical facility, which is characterized by considerable delay and inertia in the flow of heat and mass exchange. Therefore, the analysis of transient processes based on modern ideas about heat transfer is an important issue in solving technological problems of blast furnace smelting managing. A two-stage heat transfer scheme along the height of a blast furnace of modern technology presented. When studying the thermal state of a blast furnace as a control object, it is advisable to divide it into two thermal zones - the upper zone and the lower zone. The border between the zones is located in the upper part of the mixed reduction region, between the start level of coke carbon gasification and the horizon below which iron oxides are directly reduced. It was shown, that the upper and lower thermal zones have fundamental differences in heat exchange conditions and are interconnected through the index of iron direct reduction degree. The transient processes of silicon variation in the hot metal studied at variation of iron ore load, natural gas flow rate, temperature and humidity of the hot blast, oxygen content in the hot blast and slag basicity. It was shown that the oscillatory transition process is observed in case, after applying the perturbation, it will have the opposite effect on the thermal conditions of the lower and the upper stages of heat exchange in the blast furnace. The iron ore load, hot blast humidity and slag basicity were found to be the most predictable input parameters affecting the concentration of silicon in hot metal. Change in oxygen concentration in hot blast and natural gas consumption have an alternating character of influence on thermal conditions of the blast-furnace hearth. At that, the characteristics of the transient processes of blast furnaces through various channels of action vary and depend significantly on the properties of the smelted raw materials, design and operational parameters of the furnaces


2020 ◽  
Vol 786 (11) ◽  
pp. 30-34
Author(s):  
A.M. IBRAGIMOV ◽  
◽  
L.Yu. GNEDINA ◽  

This work is part of a series of articles under the general title The structural design of the blast furnace wall from efficient materials [1–3]. In part 1, Problem statement and calculation prerequisites, typical multilayer enclosing structures of a blast furnace are considered. The layers that make up these structures are described. The main attention is paid to the lining layer. The process of iron smelting and temperature conditions in the characteristic layers of the internal environment of the furnace is briefly described. Based on the theory of A.V. Lykov, the initial equations describing the interrelated transfer of heat and mass in a solid are analyzed in relation to the task – an adequate description of the processes for the purpose of further rational design of the multilayer enclosing structure of the blast furnace. A priori the enclosing structure is considered from a mathematical point of view as the unlimited plate. In part 2, Solving boundary value problems of heat transfer, boundary value problems of heat transfer in individual layers of a structure with different boundary conditions are considered, their solutions, which are basic when developing a mathematical model of a non-stationary heat transfer process in a multi-layer enclosing structure, are given. Part 3 presents a mathematical model of the heat transfer process in the enclosing structure and an algorithm for its implementation. The proposed mathematical model makes it possible to solve a large number of problems. Part 4 presents a number of examples of calculating the heat transfer process in a multilayer blast furnace enclosing structure. The results obtained correlate with the results obtained by other authors, this makes it possible to conclude that the new mathematical model is suitable for solving the problem of rational design of the enclosing structure, as well as to simulate situations that occur at any time interval of operation of the blast furnace enclosure.


2020 ◽  
Vol 2020 (13) ◽  
pp. 1607-1612
Author(s):  
A. G. Radyuk ◽  
A. E. Titlyanov ◽  
T. Yu. Sidorova
Keyword(s):  

2007 ◽  
Vol 34 (5) ◽  
pp. 415-421 ◽  
Author(s):  
Z. Qian ◽  
Z.-H. Du ◽  
L.-J. Wu

Author(s):  
Stewart Xu Cheng ◽  
James S. Wallace

Glow plugs are a possible ignition source for direct injected natural gas engines. This ignition assistance application is much different than the cold start assist function for which most glow plugs have been designed. In the cold start application, the glow plug is simply heating the air in the cylinder. In the cycle-by-cycle ignition assist application, the glow plug needs to achieve high surface temperatures at specific times in the engine cycle to provide a localized source of ignition. Whereas a simple lumped heat capacitance model is a satisfactory representation of the glow plug for the air heating situation, a much more complex situation exists for hot surface ignition. Simple measurements and theoretical analysis show that the thickness of the heat penetration layer is small within the time scale of the ignition preparation period (1–2 ms). The experiments and analysis were used to develop a discretized representation of the glow plug domain. A simplified heat transfer model, incorporating both convection and radiation losses, was developed for the discretized representation to compute heat transfer to and from the surrounding gas. A scheme for coupling the glow plug model to the surrounding gas computational domain in the KIVA-3V engine simulation code was also developed. The glow plug model successfully simulates the natural gas ignition process for a direct-injection natural gas engine. As well, it can provide detailed information on the local glow plug surface temperature distribution, which can aid in the design of more reliable glow plugs.


Author(s):  
Aleksei S. Tikhonov ◽  
Andrey A. Shvyrev ◽  
Nikolay Yu. Samokhvalov

One of the key factors ensuring gas turbine engines (GTE) competitiveness is improvement of life, reliability and fuel efficiency. However fuel efficiency improvement and the required increase of turbine inlet gas temperature (T*g) can result in gas turbine engine life reduction because of hot path components structural properties deterioration. Considering circumferential nonuniformity, local gas temperature T*g can reach 2500 K. Under these conditions the largest attention at designing is paid to reliable cooling of turbine vanes and blades. At present in design practice and scientific publications comparatively little attention is paid to detailed study of turbine split rings thermal condition. At the same time the experience of modern GTE operation shows high possibility of defects occurrence in turbine 1st stage split ring. This work objective is to perform conjugate numerical simulation (gas dynamics + heat transfer) of thermal condition for the turbine 1st stage split ring in a modern GTE. This research main task is to determine the split ring thermal condition by defining the conjugate gas dynamics and heat transfer result in ANSYS CFX 13.0 package. The research subject is the turbine 1st stage split ring. The split ring was simulated together with the cavity of cooling air supply from vanes through the case. Besides turbine 1st stage vanes and blades have been simulated. Patterns of total temperature (T*Max = 2000 °C) and pressure and turbulence level at vanes inlet (19.2 %) have been defined based on results of calculating the 1st stage vanes together with the combustor. The obtained results of numerical simulation are well coherent with various experimental studies (measurements of static pressure and temperature in supply cavity, metallography). Based on the obtained performance of the split ring cooling system and its thermal condition, the split ring design has been considerably modified (one supply cavity has been split into separate cavities, the number and arrangement of perforation holes have been changed etc.). All these made it possible to reduce considerably (by 40…50 °C) the split ring temperature comparing with the initial design. The design practice has been added with the methods which make it possible to define thermal condition of GTE turbine components by conjugating gas dynamics and heat transfer problems and this fact will allow to improve the designing level substantially and to consider the influence of different factors on aerodynamics and thermal state of turbine components in an integrated programming and computing suite.


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