scholarly journals Numerical Study on the Effect of Lambda Value (Oxygen/Fuel Ratio) on Temperature Distribution and Efficiency of a Flameless Oxyfuel Combustion System

Energies ◽  
2017 ◽  
Vol 10 (3) ◽  
pp. 338 ◽  
Author(s):  
Mersedeh Ghadamgahi ◽  
Patrik Ölund ◽  
Nils Andersson ◽  
Pär Jönsson
Keyword(s):  
Temperature Distribution ◽  
Numerical Study ◽  
Combustion System ◽  
Fuel Ratio ◽  
Oxyfuel Combustion ◽  
Oxygen Fuel

Effect of Primary Zone Operating Condition for Dilution Mixing Behavior in a Gas Turbine

2015 ◽  
Author(s):  
Wei Dai ◽  
Yuzhen Lin ◽  
Quanhong Xu ◽  
Chi Zhang ◽  
Xin Xue
Keyword(s):  
Temperature Distribution ◽  
Gas Turbine ◽  
Numerical Study ◽  
Experimental Results ◽  
Fuel Particle ◽  
Radial Temperature ◽  
Operating Condition ◽  
Fuel Ratio ◽  
Primary Zone ◽  
Exit Temperature

The exit temperature distribution had a great effect on reliability and security in a gas turbine. In this paper, the exit temperature distribution of a small engine reverse-flow combustor with three injectors test module was experimentally obtained to qualitatively analyze the influence of the primary zone operating condition by changing the fuel air ratio at the ambient pressure and temperature condition. Under the nearly identical air condition, there was no obvious difference on the mixing performance with different fuel flow rate. The hot zones occurred at the same position of the combustor exit section, and the temperature declined in the radial direction from the center. It could be seen that the radial temperature profiles in FAR of 0.022–0.03 were almost same. Malvern experimental results showed that the air fuel ratio of swirler cup ranges from 5 to 40 and the droplet distribution index n could not be increased or decreased by the ratio at different air pressure drop. The air fuel ratio of combustor swirl cup had reached more than 5 which fuel particle had been nearly stable and not got some variation by changing the fuel mass rate. As a result, the increase of fuel air ratio had no impact on fuel atomization uniformity in combustor dome. The fuel had been completely atomized when the combustor fuel air ratio ranged from 0.022 to 0.03, and its impact on the droplet size and uniformity of fuel could be neglected. With the uniform fuel spray, a numerical study of the whole combustor had been made to analyze the strong relation between swirl flow and jets of primary holes and dilution holes. The dilution jets had a strong effect on quenching flame and temperature dilution. Along the combustor flow direction, the temperature difference became less and less obvious, the addition of fuel would enhance the combustion intensity mainly in combustion zone, but with an effect of dilution jet, the temperature distributions had little deviation when increasing the fuel air ratio. And it showed a same phenomenon that different fuel air ratio would make the same exit temperature distribution which was found to be in line with the experimental results. In a word, for the primary zone operating condition in the combustor, it almost had no effect on the temperature distribution at the exit of the combustor by changing the fuel air ratio from 0.022 to 0.030 in primary zone at normal pressure and temperature condition.

scholarly journals Numerical study on temperature distribution of tunnel structure in fires

2021 ◽  
Vol 25 ◽  
pp. 100874
Author(s):  
Xin Xu ◽  
Guoqing Zhu ◽  
Xiaojin Zhang ◽  
Guoqiang Chai ◽  
Tianwei Chu
Keyword(s):  
Temperature Distribution ◽  
Numerical Study ◽  
Tunnel Structure

Full-Engine Field Test: An Approach to Improve the Gas Turbine Combustion System

1988 ◽  
Vol 110 (4) ◽  
pp. 677-685
Author(s):  
M. Gianola
Keyword(s):  
Experimental Data ◽  
Temperature Distribution ◽  
Gas Turbine ◽  
Field Test ◽  
Test Bench ◽  
Fuel Oil ◽  
Ignition Process ◽  
Exit Plane ◽  
Combustion System ◽  
Oil And Natural Gas

For purposes of both final verification and optimization of TG 20 and TG 50 combustion systems, test programs have been carried out directly on full engines operating in the field, as well as in the test bench. These programs were carried out in two separate phases: the first one directed to determine the behavior at load by means of experimental data acquisition, including temperature distribution on the combustor exit plane for different burner arrangements, and the second one directed to optimize the ignition process and the acceleration sequence. This paper, after a brief description of the instrumentation used for each test, reports the most significant results burning both fuel oil and natural gas. Moreover, some peculiar operational problems are mentioned, along with their diagnosis and the corrections applied to the combustion system to solve them.

Effect of Wall Conduction on Combined Free and Forced Laminar Convection in Horizontal Rectangular Channels

1987 ◽  
Vol 109 (4) ◽  
pp. 936-942 ◽  
Author(s):  
G. J. Hwang ◽  
F. C. Chou
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Temperature Distribution ◽  
Finite Difference ◽  
Aspect Ratio ◽  
Finite Difference Method ◽  
Numerical Study ◽  
Fully Developed Flow ◽  
Rectangular Channels ◽  
Laminar Convection

This paper presents a numerical study of the effect of peripheral wall conduction on combined free and forced laminar convection in hydrodynamically and thermally fully developed flow in horizontal rectangular channels with uniform heat input axially, In addition to the Prandtl number, the Grashof number Gr+, and the aspect ratio γ, a parameter Kp indicating the significance of wall conduction plays an important role in heat transfer. A finite-difference method utilizing a power-law scheme is employed to solve the system of governing partial differential equations coupled with the equation for wall conduction. The numerical solution covers the parameters: Pr = 7.2 and 0.73, γ = 0.5, 1, and 2, Kp = 10−4–104, and Gr+ = 0–1.37×105. The flow patterns and isotherms, the wall temperature distribution, the friction factor, and the Nusselt number are presented. The results show a significant effect of the conduction parameter Kp.

Cooling Considerations for Design of a Radial Inflow Turbine

1977 ◽  
Author(s):  
A. Hamed ◽  
Y. Sheoran ◽  
W. Tabakoff
Keyword(s):  
Temperature Distribution ◽  
Numerical Study ◽  
Computer Time ◽  
Coolant Temperature ◽  
Internal Cooling ◽  
Present Formulation ◽  
Mechanical Integrity ◽  
Cooling Design ◽  
Time Savings ◽  
Radial Inflow Turbine

A numerical study to determine the temperature distribution in the rotor of a radial inflow turbine is presented. Internal cooling passages are modeled in the present formulation in order to carry out solid and coolant temperature computations simultaneously resulting in a considerable computer time savings. The stresses due to centrifugal and thermal loadings are determined in an actual rotor and the effect of cooling design on its mechanical integrity is discussed.

scholarly journals Numerical Study on the Effects of Relative Diameters on the Performance of Small Modular Reactors Driven by Natural Circulation

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5881
Author(s):  
Young Jin Kim ◽  
Byung Jin Lee ◽  
Kunwoo Yi ◽  
Yoon Jae Choe ◽  
Min Chul Lee
Keyword(s):  
Temperature Distribution ◽  
Steam Generator ◽  
Flow Rate ◽  
Numerical Study ◽  
Natural Circulation ◽  
Hydraulic Parameters ◽  
Small Modular Reactors ◽  
Velocity Changes ◽  
Energy Equations ◽  
Tube Pitch

Most of the small modular reactors (SMRs) under development worldwide present the same components: an integral reactor vessel with a low-positioned core as the heat source and a high-positioned steam generator as the heat sink. Moreover, some SMRs are being designed to be driven by natural circulation during normal power generation. This work focused on such designs and on their performance, considering the changes generated by the geometric and hydraulic parameters of the system. Numerical simulations using mass, momentum, and energy equations that considered buoyancy forces were performed to determine the effects of various geometric and hydraulic parameters, such as diameters and flow resistances, on the reactor’s performance. It was found that nonuniform diameters promote velocity changes that affect the natural circulation flow rate. Moreover, the reactor’s temperature distribution depends on the steam generator tube pitch. Therefore, the hydraulic diameters of the reactor’s coolant passages should be maintained as uniform as possible to obtain a more uniform temperature distribution and a larger mass flow rate in SMRs.

scholarly journals Experimental and numerical study of the effect of coil structure on induction nitriding temperature field

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402093848
Author(s):  
Kangjie Song ◽  
Jing Guan ◽  
Kunmao Li ◽  
Jing Liu
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Induction Heating ◽  
Current Density ◽  
Numerical Study ◽  
Radial Temperature ◽  
Current Frequency ◽  
Variable Pitch ◽  
Variable Radius ◽  
Heating Efficiency

The axial and radial temperature distributions of an induction heating workpiece considerably impact the subsequent nitriding process. To obtain a satisfactory temperature distribution, an equal pitch coil, a variable pitch coil, and a variable radius coil were designed. Furthermore, an induction heating model that exhibits electromagnetic and temperature field coupling was established; thus, the effects of the current density and frequency on the heating efficiency and temperature distribution of the workpiece were analyzed and compared. In addition, an induction heating experiment was conducted to verify the model. According to the numerical results, the variable radius coil can reduce the axial temperature difference in comparison with equal pitch coil and variable pitch coil. Hence, the workpiece heated using the variable radius coil can achieve a better temperature distribution when compared with those heated by the equal pitch coil and variable pitch coil, with appropriate current density and current frequency values.

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