Particle and Vapor Deposition in Coal-Fired Gas Turbines

1986 ◽  
Author(s):  
R. K. Ahluwalia ◽  
K. H. Im ◽  
C. F. Chuang ◽  
J. C. Hajduk
Keyword(s):  
Vapor Deposition ◽  
Gas Turbines ◽  
Particle Deposition ◽  
Scaling Laws ◽  
Turbine Blades ◽  
Cascade Flow ◽  
Nucleation Mechanisms ◽  
Flow Through ◽  
Particle Laden Flow ◽  
Deposition Models

Mechanistic models have been developed for particle and vapor deposition on the blades of coal-fired gas turbines. The particle deposition models include the simultaneous contribution of Brownian and turbulent diffusion, thermophoresis, eddy impaction, and inertial impingement. The diffusive mechanisms have been validated against experimental data for low-speed cascade flow and particle-laden flow through pipes. The inertial deposition treatment is shown to collapse to the well-known expression for particle capture in a flow turning around a bend. A method is presented for calculating Na2SO4 and K2SO4 vapor deposition on cooled blades. Scaling laws are formulated for estimating the contribution of boundary layer homogeneous and heterogeneous nucleation mechanisms for highly cooled turbine blades.

scholarly journals A Novel Evaluation Method For Particle Deposition Measurement

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 927-934
Author(s):  
Tao Song ◽  
Chao Liu ◽  
Hengxuan Zhu ◽  
Min Zeng ◽  
Jin Wang
Keyword(s):  
Layer Thickness ◽  
Dielectric Layer ◽  
Gas Turbines ◽  
Particle Deposition ◽  
Optimization Design ◽  
Turbine Blades ◽  
Simulation Software ◽  
Circuit Board ◽  
Normal Operation ◽  
Mass Detection

Abstract Normal operation of gas turbines will be affected by deposition on turbine blades from particles mixed in fuels. This research shows that it is difficult to monitor the mass of the particles deposition on the wall surface in real time. With development of electronic technology, the antenna made of printed circuit board (PCB) has been widely used in many industrial fields. Microstrip antenna is first proposed for monitoring particles deposition to analyse the deposition law of the particles accumulated on the wall. The simulation software Computer Simulation Technology Microwave Studio (CST MWS) 2015 is used to conduct the optimization design of the PCB substrate antenna. It is found that the S11 of vivaldi antenna with arc gradient groove exhibits a monotonous increase with the increase of dielectric layer thickness, and this antenna is highly sensitive to the dielectric layer thickness. Moreover, a cold-state test is carried out by using atomized wax to simulate the deposition of pollutants. A relationship as a four number of times function is found between the capacitance and the deposited mass. These results provide an important reference for the mass detection of the particle deposition on the wall, and this method is suitable for other related engineering fields.

Modelling Particle Deposition in Gas Turbines Employed in Advanced Coal-Fired Systems

1994 ◽  
Author(s):  
John E. Fackrell ◽  
Kevin Brown ◽  
John B. Young
Keyword(s):  
Gas Turbines ◽  
Particle Deposition ◽  
Turbine Blades ◽  
Ambient Conditions ◽  
Stopping Distance ◽  
Trajectory Calculations ◽  
Particulate Contamination ◽  
Distance Model ◽  
Systems Modelling ◽  
Low Levels

In many advanced coal-fired plant the gases being passed to the gas turbine will contain low levels of small particles. These particles may deposit on, or cause erosion of, the turbine blades, affecting the economic and technical viability of such systems. Modelling work has been undertaken to assess the effects of particulate contamination in coal-fired systems. A number of different models for the particle behaviour have been developed and used, depending on the particular application involved. The behaviour of particles of a few microns in size and upwards is dominated by inertial effects and has been modelled by performing particle trajectory calculations in the turbine flow field, this having been first calculated with a turbine flow code. Smaller particles tend to be deposited by a process of diffusion through the turbine blade boundary layers. Two modelling approaches have been undertaken for diffusive deposition. The simpler approach is based on a heat transfer analogy combined with extra prescriptions for thermophoresis and eddy impaction effects. The more complicated approach involves a numerical solution of the particle diffusion equation within the boundary layer, including the effects of thermophoresis and using a stopping distance model for eddy impaction effects. Predictions from the models have been compared with experimental results at realistic conditions obtained in a PFBC rig at Grimethorpe and with laboratory results at ambient conditions.

Advanced Particle Control for Coal-Based Power Generation Systems

1989 ◽  
Author(s):  
Steven J. Bossart
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Speed ◽  
Particle Deposition ◽  
Power Plants ◽  
Turbine Blades ◽  
Combined Cycle ◽  
Department Of Energy ◽  
Power Generation Systems

The Morgantown Energy Technology Center (METC) of the U.S. Department of Energy (DOE) is actively sponsoring research to develop coal-based power generation systems that use coal more efficiently and economically and with lower emissions than conventional pulverized-coal power plants. Some of the more promising of the advanced coal-based power generation systems are shown in Figure 1: pressurized fluidized-bed combustion combined-cycle (PFBC), integrated gasification combined-cycle (IGCC), and direct coal-fueled turbine (DCFT). These systems rely on gas turbines to produce all or a portion of the electrical power generation. An essential feature of each of these systems is the control of particles at high-temperature and high-pressure (HTHP) conditions. Particle control is needed in all advanced power generation systems to meet environmental regulations and to protect the gas turbine and other major system components. Particles can play a significant role in damaging the gas turbine by erosion, deposition, and corrosion. Erosion is caused by the high-speed impaction of particles on the turbine blades. Particle deposition on the turbine blades can impede gas flow and block cooling air. Particle deposition also contributes to corrosive attack when alkali metal compounds adsorbed on the particles react with the gas turbine blades. Incorporation of HTHP particle control technologies into the advanced power generation systems can reduce gas turbine maintenance requirements, increase plant efficiency, reduce plant capital cost, lower the cost of electricity, reduce wastewater treatment requirements, and eliminate the need for post-turbine particle control to meet New Source Performance Standards (NSPS) for particle emissions.

Study of Particles Deposition in Gas Turbine Blades in Presence of Film Cooling

2014 ◽  
Author(s):  
Domenico Borello ◽  
Luca D’Angeli ◽  
Alessandro Salvagni ◽  
Paolo Venturini ◽  
Franco Rispoli
Keyword(s):  
Gas Turbine ◽  
Film Cooling ◽  
Particle Deposition ◽  
Turbine Blades ◽  
Integrated Approach ◽  
Solid Particles ◽  
Probability Method ◽  
Wall Region ◽  
Particles Trajectories ◽  
Particle Laden Flow

Exhaust entering the gas turbine is usually fed with solid particles produced in the combustion of hydrocarbons (ashes, unburned char, etc.). Then, the interaction between the particles motion and the film cooling jets must be properly addressed. Here an integrated approach based on an Eulerian-Lagrangian scheme for particle-laden flow was applied to a real turbomachinery case. The code was preliminary assessed by simulating two simplified test cases: a) 3-D cooling jet in a channel; b) 2-D turbine cascade with film cooling. These cases were selected to separately validate the main effects here considered: a) interaction of particles trajectories and 3D cooling jets; b) effect of the cooling jets on surface temperature and particles trajectory and possibly on particle deposition, in comparison with the non-cooled case. Finally, 3D simulation of the particle-laden flow around a real E3 gas turbine vane with and without film cooling was performed. Flow features, particles trajectories and deposit on the blade are presented. The compressible flow field was simulated using the OpenFOAM code obtaining credible predictions of the velocity and temperature field. Then the P-Track code developed by the authors was applied for tracking the particles trajectories and determining the deposit on the solid surface. As the temperature are relatively high, the sticking probability method, that is strongly dependent on the temperature itself, was used here. The results showed that the presence of the cooling jets affect deeply the deposit following two main causes: the influence of the jets in removing the fluid from the close-to-the-wall region and the reduction of temperature along the blade.

scholarly journals Computational fluid dynamics calculus and analysis for gas and water turbines

2018 ◽  
Vol 145 ◽  
pp. 03014
Author(s):  
Valeriu Vilag ◽  
Ivanka Zheleva ◽  
Jenia Popescu ◽  
Krasimir Tujarov
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Practical Applications ◽  
Water Turbine ◽  
Flow Through ◽  
Similarities And Differences ◽  
The Many ◽  
Water Turbines

The paper presents the utilization of Computational Fluid Dynamics for calculating the flow through turbines. The first and most extended part of the paper is focused on gas turbines where the simulations are very precise and can be successfully used even for optimization of blade geometry. Flow details and results for an axial turbine are presented along with a proposal of optimization algorithm. The second part of the paper is dedicated to water turbines and there is presented the calculus realized for a kinetic water turbine. I this case, the flow around the turbine blades is presented and some data about the predicted performances along with many ways for improving the simulations. The conclusions of the paper are related to similarities and differences between the two types of simulations and to the many ways of using these simulations for practical applications.

Improving Efficiency in Robot Assisted Belt Grinding of High Performance Materials

2014 ◽  
Vol 907 ◽  
pp. 139-149 ◽  
Author(s):  
Eckart Uhlmann ◽  
Florian Heitmüller
Keyword(s):  
Gas Turbines ◽  
High Performance ◽  
Scale Effects ◽  
Turbine Blades ◽  
Repair Process ◽  
Industrial Robots ◽  
Robot Assisted ◽  
Belt Grinding ◽  
Economy Of Scale ◽  
The Individual

In gas turbines and turbo jet engines, high performance materials such as nickel-based alloys are widely used for blades and vanes. In the case of repair, finishing of complex turbine blades made of high performance materials is carried out predominantly manually. The repair process is therefore quite time consuming. And the costs of presently available repair strategies, especially for integrated parts, are high, due to the individual process planning and great amount of manually performed work steps. Moreover, there are severe risks of partial damage during manually conducted repair. All that leads to the fact that economy of scale effects remain widely unused for repair tasks, although the piece number of components to be repaired is increasing significantly. In the future, a persistent automation of the repair process chain should be achieved by developing adaptive robot assisted finishing strategies. The goal of this research is to use the automation potential for repair tasks by developing a technology that enables industrial robots to re-contour turbine blades via force controlled belt grinding.

A Three-Dimensional Analysis of Particle Deposition for the Modified Chemical Vapor Deposition (MCVD) Process

1992 ◽  
Vol 114 (3) ◽  
pp. 735-742 ◽  
Author(s):  
Y. T. Lin ◽  
M. Choi ◽  
R. Greif
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Particle Deposition ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Secondary Flows ◽  
Circumferential Direction ◽  
Forced Flow ◽  
Flow Rates ◽  
Entry Length

A study has been made of the deposition of particles that occurs during the modified chemical vapor deposition (MCVD) process. The three-dimensional conservation equations of mass, momentum, and energy have been solved numerically for forced flow, including the effects of buoyancy and variable properties in a heated, rotating tube. The motion of the particles that are formed is determined from the combined effects resulting from thermophoresis and the forced and secondary flows. The effects of torch speed, rotational speed, inlet flow rate, tube radius, and maximum surface temperature on deposition are studied. In a horizontal tube, buoyancy results in circumferentially nonuniform temperature and velocity fields and particle deposition. The effect of tube rotation greatly reduces the nonuniformity of particle deposition in the circumferential direction. The process is chemical-reaction limited at larger flow rates and particle-transport limited at smaller flow rates. The vertical tube geometry has also been studied because its symmetric configuration results in uniform particle deposition in the circumferential direction. The “upward” flow condition results in a large overall deposition efficiency, but this is also accompanied by a large “tapered entry length.”

Development and Fabrication of Silicon Nitride Components for Ceramic Gas Turbine

1997 ◽  
Author(s):  
Keisuke Makino ◽  
Ken-Ichi Mizuno ◽  
Toru Shimamori
Keyword(s):  
High Temperature ◽  
Silicon Nitride ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Blades ◽  
High Strength ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Spark Plug ◽  
Power Turbine

NGK Spark Plug Co., Ltd. has been developing various silicon nitride materials, and the technology for fabricating components for ceramic gas turbines (CGT) using theses materials. We are supplying silicon nitride material components for the project to develop 300 kW class CGT for co-generation in Japan. EC-152 was developed for components that require high strength at high temperature, such as turbine blades and turbine nozzles. In order to adapt the increasing of the turbine inlet temperature (TIT) up to 1,350 °C in accordance with the project goals, we developed two silicon nitride materials with further unproved properties: ST-1 and ST-2. ST-1 has a higher strength than EC-152 and is suitable for first stage turbine blades and power turbine blades. ST-2 has higher oxidation resistance than EC-152 and is suitable for power turbine nozzles. In this paper, we report on the properties of these materials, and present the results of evaluations of these materials when they are actually used for CGT components such as first stage turbine blades and power turbine nozzles.

An Optimization Design Platform for Fir-Tree Root and Groove for Steam Turbine

2018 ◽  
Author(s):  
Deqi Yu ◽  
Xiaojun Zhang ◽  
Jiandao Yang ◽  
Kai Cheng ◽  
Weilin Shu ◽  
...  
Keyword(s):  
Stress Concentration ◽  
Steam Turbine ◽  
Gas Turbines ◽  
High Speed ◽  
Optimization Design ◽  
Turbine Blades ◽  
Local Stress ◽  
Optimization Method ◽  
Steam Turbines ◽  
Geometry Configuration

Fir-tree root and groove profiles are widely used in gas turbine and steam turbine. Normally, the fir-tree root and groove are characterized with straight line, arc or even elliptic fillet and splines, then the parameters of these features were defined as design variables to perform root profile optimization. In ultra-long blades of CCPP and nuclear steam turbines and high-speed blades of industrial steam turbine blades, both the root and groove strength are the key challenges during the design process. Especially, in industrial steam turbines, the geometry of blade is very small but the operation velocity is very high and the blade suffers stress concentration severely. In this paper, two methods for geometry configuration and relevant optimization programs are described. The first one is feature-based using straight lines and arcs to configure the fir-tree root and groove geometry and genetic algorithm for optimization. This method is quite fit for wholly new root and groove design. And the second local optimization method is based on B-splines to configure the geometry where the local stress concentration occurs and the relevant optimization algorithm is used for optimization. Also, several cases are studied as comparison by using the optimization design platform. It can be used not only in steam turbines but also in gas turbines.

Sign in / Sign up

Export Citation Format

Share Document