Development of a CFD-Based Coal Pipe Design Tool

2005 ◽  
Author(s):  
Gengxun Huang ◽  
Kenneth M. Bryden
Keyword(s):  
Power Plant ◽  
Cross Section ◽  
Small Region ◽  
Design Tool ◽  
Plant Performance ◽  
Design Stage ◽  
Radius Of Curvature ◽  
Outlet Cross Section ◽  
Curved Pipe ◽  
Pipe Cross Section

In a coal-fired power plant, pulverized coal, using air as a transport medium, is pneumatically transported toward different burner nozzles by splitting the large pipe into small pipes through bifurcators or trifurcators. The combustion efficiency of the burner is dependent on matching the air and coal in these pipes. Increasingly tight emission standards also make the balance of air and coal a very critical factor for the success of the power plant. Coal roping occurs when the gas-solid flow passes through a curved pipe. The momentum of the particles carries them to the outside of the wall, concentrating in a small region. Therefore, the particle concentration in this small region is much higher than the other part of the pipe cross-section. Coal roping upstream of a coal distributor (bifurcator) can create a significant imbalance in coal loading in the split between the two branches. This can significantly impact plant performance and increase NOx production. Previous research [2] has shown that coal rope characteristics depend on many parameters; the geometry (i.e., elbow radius of curvature-to-pipe diameter ratio, pipe orientation, orifice opening, and the locations of orifices) of the coal pipe, which is determined at the design stage, will strongly affect the coal distribution in the outlet of coal pipes. This characteristic of coal roping indicates that optimizing the pipe geometry may be helpful in getting a more uniform coal distribution at the pipe’s outlet cross-section and minimizing the problems caused by imbalance between burners. In this paper, we present the CFD-based coal pipeline design tool to achieve the evenly distributed coal particle distribution across the pipe cross-section.

Unsteady viscous flow in a curved pipe

1971 ◽  
Vol 45 (1) ◽  
pp. 13-31 ◽  
Author(s):  
W. H. Lyne
Keyword(s):  
Reynolds Number ◽  
Pressure Gradient ◽  
Secondary Flow ◽  
Cross Section ◽  
Kinematic Viscosity ◽  
Asymptotic Theory ◽  
Circular Cross Section ◽  
Radius Of Curvature ◽  
Curved Pipe ◽  
Unsteady Viscous Flow

The flow in a pipe of circular cross-section which is coiled in a circle is studied, the pressure gradient along the pipe varying sinusoidally in time with frequency ω. The radius of the pipeais assumed small in relation to the radius of curvature of its axisR. Of special interest is the secondary flow generated by centrifugal effects in the plane of the cross-section of the pipe, and an asymptotic theory is developed for small values of the parameter β = (2ν/ωa2)½, where ν is the kinematic viscosity of the fluid. The secondary flow is found to be governed by a Reynolds number$R_s = \overline{W}^2a/R \omega\nu$, where$\overline{W}$is a typical velocity along the axis of the pipe, and asymptotic theories are developed for both small and large values of this parameter. For sufficiently small values of β it is found that the secondary flow in the interior of the pipe is in the opposite sense to that predicted for a steady pressure gradient, and this is verified qualitatively by an experiment described at the end of the paper.

On the steady laminar flow of an incompressible viscous fluid in a curved pipe of elliptical cross-section

1985 ◽  
Vol 158 ◽  
pp. 329-340 ◽  
Author(s):  
H. C. Topakoglu ◽  
M. A. Ebadian
Keyword(s):  
Secondary Flow ◽  
Cross Section ◽  
Circular Cross Section ◽  
Elliptical Cross Section ◽  
Radius Of Curvature ◽  
Elliptical Cross ◽  
Curved Pipe ◽  
Curved Pipes ◽  
Ellipticity Ratio ◽  
Explicit Expressions

A literature survey (Berger, Talbot & Yao 1983) indicates that laminar viscous flow in curved pipes has been extensively investigated. Most of the existing analytical results deal with the case of circular cross-section. The important studies dealing with elliptical cross-sections are mainly due to Thomas & Walters (1965) and Srivastava (1980). The analysis of Thomas & Walters is based on Dean's (1927, 1928) approach in which the simplified forms of the momentum and continuity equations have been used. The analysis of Srivastava is essentially a seminumerical approach, in which no explicit expressions have been presented.In this paper, using elliptic coordinates and following the unsimplified formulation of Topakoglu (1967), the flow in a curved pipe of elliptical cross-section is analysed. Two different geometries have been considered: (i) with the major axis of the ellipse placed in the direction of the radius of curvature; and (ii) with the minor axis of the ellipse placed in the direction of the radius of curvature. For both cases explicit expressions for the first term of the expansion of the secondary-flow stream function as a function of the ellipticity ratio of the elliptic section have been obtained. After selecting a typical numerical value for the ellipticity ratio, the secondary-flow streamlines are plotted. The results are compared with that of Thomas & Walters. The remaining terms of the expansion of the flow field are not included, but they will be analysed in a future paper.

scholarly journals Data Driven Modelling of Nuclear Power Plant Performance Data as Finite State Machines

Modelling ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 43-62
Author(s):  
Kshirasagar Naik ◽  
Mahesh D. Pandey ◽  
Anannya Panda ◽  
Abdurhman Albasir ◽  
Kunal Taneja
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Finite State Machine ◽  
State Machine ◽  
Plant Performance ◽  
Series Data ◽  
Cyberphysical Systems ◽  
Finite State ◽  
Machine Representation

Accurate modelling and simulation of a nuclear power plant are important factors in the strategic planning and maintenance of the plant. Several nonlinearities and multivariable couplings are associated with real-world plants. Therefore, it is quite challenging to model such cyberphysical systems using conventional mathematical equations. A visual analytics approach which addresses these limitations and models both short term as well as long term behaviour of the system is introduced. Principal Component Analysis (PCA) followed by Linear Discriminant Analysis (LDA) is used to extract features from the data, k-means clustering is applied to label the data instances. Finite state machine representation formulated from the clustered data is then used to model the behaviour of cyberphysical systems using system states and state transitions. In this paper, the indicated methodology is deployed over time-series data collected from a nuclear power plant for nine years. It is observed that this approach of combining the machine learning principles with the finite state machine capabilities facilitates feature exploration, visual analysis, pattern discovery, and effective modelling of nuclear power plant data. In addition, finite state machine representation supports identification of normal and abnormal operation of the plant, thereby suggesting that the given approach captures the anomalous behaviour of the plant.

Performance Testing of Coal Fired Power Plants

2007 ◽  
Author(s):  
Shane E. Powers ◽  
William C. Wood
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Performance Test ◽  
Model Development ◽  
Performance Testing ◽  
The United States ◽  
Plant Performance ◽  
Cycle Performance ◽  
Test Program

With the renewed interest in the construction of coal-fired power plants in the United States, there has also been an increased interest in the methodology used to calculate/determine the overall performance of a coal fired power plant. This methodology is detailed in the ASME PTC 46 (1996) Code, which provides an excellent framework for determining the power output and heat rate of coal fired power plants. Unfortunately, the power industry has been slow to adopt this methodology, in part because of the lack of some details in the Code regarding the planning needed to design a performance test program for the determination of coal fired power plant performance. This paper will expand on the ASME PTC 46 (1996) Code by discussing key concepts that need to be addressed when planning an overall plant performance test of a coal fired power plant. The most difficult aspect of calculating coal fired power plant performance is integrating the calculation of boiler performance with the calculation of turbine cycle performance and other balance of plant aspects. If proper planning of the performance test is not performed, the integration of boiler and turbine data will result in a test result that does not accurately reflect the true performance of the overall plant. This planning must start very early in the development of the test program, and be implemented in all stages of the test program design. This paper will address the necessary planning of the test program, including: • Determination of Actual Plant Performance. • Selection of a Test Goal. • Development of the Basic Correction Algorithm. • Designing a Plant Model. • Development of Correction Curves. • Operation of the Power Plant during the Test. All nomenclature in this paper utilizes the ASME PTC 46 definitions for the calculation and correction of plant performance.

scholarly journals Derivation of power loss factors to evaluate the impact of postcombustion CO2 capture processes on steam power plant performance

2011 ◽  
Vol 4 ◽  
pp. 1385-1394 ◽  
Author(s):  
Sebastian Linnenberg ◽  
Ulrich Liebenthal ◽  
Jochen Oexmann ◽  
Alfons Kather
Keyword(s):  
Power Plant ◽  
Co2 Capture ◽  
Power Loss ◽  
Plant Performance ◽  
Steam Power ◽  
Steam Power Plant ◽  
The Impact ◽  
Loss Factors

A Simulation of a Generalized Thermal Radiating Fin

SIMULATION ◽  
1964 ◽  
Vol 2 (6) ◽  
pp. 19-22
Author(s):  
M.T. Janicke ◽  
L.C. Just
Keyword(s):  
Power Plant ◽  
Cross Section ◽  
Construction Material ◽  
Heat Removal ◽  
Thermodynamic Cycle ◽  
Space Applications ◽  
Maximum Heat ◽  
Electrical Systems ◽  
Extra Weight ◽  
The Relationship

The purpose of this paper is to provide a method for designing radiator fins with maximum heat removal capability per pound of construction material. This problem becomes important when radiators are designed for space applications, since all of the heat from the thermodynamic cycle must be removed by means of radiation. Moreover, space transportation vehicles are seriously limited as to payload, so that weight must be saved in all parts of a power plant. An increase in the output of a space power plant does not change the reactor, turbine, and generator as much as the radiator, with the result that, for megawatt electrical systems, the radiator is the dominant weight contributing component. A radiator could be built of coolant tubes alone, but this increases certain hazards. Meteor punctures can occur, so that the amount of area devoted to coolant tubes should be reduced as much as pos sible. Fins attached between the tubes can perform this function by extending the heat radiating surface. The extra weight of the fins is partly compensated for by a reduction in tubes and coolant. Extra savings can occur if the weight of the fin is minimized; optimum thickness, length, and cross section must be found. This paper studies the relationship between fin cross- section and radiating power.

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