scholarly journals Experimental Research and CFD Calculations Based Investigations Into Gas Flow in a Short Segment of a Heavily Worn Straight Through Labyrinth Seal

2017 ◽  
Vol 24 (2) ◽  
pp. 83-88 ◽  
Author(s):  
Damian Joachimiak ◽  
Piotr Krzyślak
Keyword(s):  
Experimental Research ◽  
Power Plants ◽  
Gas Flow ◽  
Labyrinth Seal ◽  
Steam Turbines ◽  
Static Pressure Distribution ◽  
Flow Parameters ◽  
Working Medium ◽  
Theoretical Assumptions ◽  
Flow Phenomena

Abstract Steam turbines are used as propulsion components in not only power plants but also on merchant and naval ships. The geometry of the steam turbine seals changes throughout the machine life cycle. The rate of deterioration of these seals, in turn, affects heavily the efficiency of the thermal machine. However, the literature overview does not provide any research reports on flow phenomena occurring in heavily deteriorated seals. The paper describes the course and results of investigations into a model straight through labyrinth seal composed of 4 discs, each with the slot height of 2 mm. The investigations have been conducted with air as the working medium. Changes of gas flow parameters due to wear were analysed. Based on the experimental data, more intensive leakage was observed as the result of the increased slot height. The static pressure distribution along the examined segment was measured. The experimentally recorded distribution differed remarkably from the theoretical assumptions. Another part of the experimental research focused on comparing the gas velocities at points situated upstream of the first and second seal disc. The velocity measurements were carried out using a constant temperature wire probe. This part of the investigations provided opportunities for analysing the influence of seal wear on gas flow conditions in the seal segment. The paper compares the results of the experimental research with those obtained using the CFX software. The presented results of velocity distributions provide a clear picture of the nature of the gas flow in the seal, which enables its analysis.

scholarly journals Analysis of the impact of the labyrinth seal geometric parameters on the leakage

2021 ◽  
Vol 323 ◽  
pp. 00015
Author(s):  
Damian Joachimiak ◽  
Piotr Krzyślak
Keyword(s):  
Experimental Research ◽  
Gas Flow ◽  
Labyrinth Seal ◽  
Gas Pressure ◽  
Geometric Parameters ◽  
Labyrinth Seals ◽  
Flow Parameters ◽  
Number Of Teeth ◽  
The Impact ◽  
Size Data

This paper includes results of experimental research and CFD calculations concerning gas flow in segments of straight through labyrinth seals of fixed length and varying number of teeth. Relation between the number of teeth and the leakage is analyzed in this paper. Authors determined the range of teeth number for which the minimum leakage was achieved. They focused particularly on the analysis of geometry with maximum number of teeth which fell within the range of the minimum leakage. For this geometry they examined the relation between the thickness of the teeth and the distribution of gas pressure and velocity along the seal and the leakage size. Data presented in this paper indicate that the teeth thickness has a significant impact on the flow parameters.

scholarly journals Experimental Research of Gaseous Emissions Impact on the Performance of New-Design Cylindrical Multi-Channel Cyclone with Adjustable Half-Rings

2022 ◽  
Vol 14 (2) ◽  
pp. 902
Author(s):  
Aleksandras Chlebnikovas ◽  
Dainius Paliulis ◽  
Kristina Kilikevičienė ◽  
Artūras Kilikevičius
Keyword(s):  
Experimental Research ◽  
Gas Flow ◽  
Collection Efficiency ◽  
Fine Particulate Matter ◽  
Air Flow ◽  
Gaseous Emissions ◽  
Channel System ◽  
Flow Parameters ◽  
The Impact ◽  
Channel Type

Cyclones are widely used for separating particles from gas in energy production objects. The efficiency of conventional centrifugal air cleaning devices ranges from 85 to 90%, but the weakness of many cyclones is the low collection efficiency of particles less than 10 μm in diameter. The novelty of this work is the research of the channel-type treatment device, with few levels adapted for precipitation of fine particulate matter, acting by a centrifugal and filtration principle. Many factors have an impact on cyclone efficiency—humidity, temperature, gas (air) composition, airflow velocity and etc. Many scientists evaluated only the effect of origin and size of PM on cyclone efficiency. The effect of gas (air) composition and temperature, and humidity on the multi-channel cyclone-separator efficiency still demands contributions. Complex theoretical and experimental research on air flow parameters and the efficiency of a cylindrical eight-channel system with adjustable half-rings for removing fine-dispersive particles (<20 μm) was carried out. The impact of air humidity and temperature on air flow, and gaseous smoke components on the removal of wood ashes was analyzed. The dusty gas flow was regulated. During the experiment, the average velocity of the cyclone was 16 m/s, and the temperature was 20–50 °C. The current paper presents experimental research results of wood ash removal in an eight-channel cyclone and theoretical methodology for the calculation of airflow parameters and cyclone effectiveness.

scholarly journals The Analysis of the Possibility of Feeding a Liquid Catalyst to a Coal Dust Channel

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8521
Author(s):  
Zdzisław Bielecki ◽  
Marek Ochowiak ◽  
Sylwia Włodarczak ◽  
Andżelika Krupińska ◽  
Magdalena Matuszak ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Experimental Research ◽  
Lower Energy ◽  
Power Plants ◽  
Large Scale ◽  
Coal Dust ◽  
Exhaust Gases ◽  
Flow Parameters ◽  
Channel Outlet

This article presents the concept of a method of improving the dynamics of combustion in boilers operating in power plants, cogeneration plants, and heating plants by introducing a catalyst that is fed with a carrier in the form of droplets. Thanks to the proposed method, a greater degree of fuel burnout can be obtained, which, in turn, results in lower energy consumption in the case of producing the same amount of power. The parameters of the emitted exhaust gases and ash are also improved. The method described in the article involves the adding of a catalyst to the dust pipe of the boiler, which improves the combustion parameters. The catalyst was implemented using a sprayer/nebulizer. In order to obtain the correct flow parameters, the sprayer was modeled using CFD calculations. The calculations include trajectories, velocities and concentrations with regards to various flow parameters. Particular attention should be paid to the model of the evaporation of moving droplets. The results of these calculations enable the parameters that guarantee that the catalyst reaches the dust channel outlet in the desired form to be assessed. The analysis is an introduction to experimental research that is carried out on a medium and large scale.

Comparison of the Two Methods to Determine State Parameters of Wet Saturated Steam

2014 ◽  
Vol 904 ◽  
pp. 330-334
Author(s):  
Ya Rong Wang ◽  
Pei Rong Wang
Keyword(s):  
Thermodynamic Properties ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
The State ◽  
Saturated Steam ◽  
Steam Turbines ◽  
Water Steam ◽  
Working Medium

Water steam is widely used in steam turbines, steam engines, nuclear power plants and many other places. As a kind of working medium, it has many advantages, such as proper thermodynamic properties, non-toxic, odorless ,cheap, and so on. So it is very important how to determine the state parameters of water steam. In this paper we describe the two methods to determine state parameters of wet saturated steam, and the two methods are compared.

scholarly journals Experimental research and CFD analysis of flow parameters in a SCR system for the original part and WALKER’s replacement

2019 ◽  
Vol 179 (4) ◽  
pp. 13-20
Author(s):  
Damian KURZYDYM ◽  
Adam KLIMANEK ◽  
Zbigniew ŻMUDKA
Keyword(s):  
Reverse Engineering ◽  
Experimental Research ◽  
Gas Flow ◽  
Catalytic Reduction ◽  
Ansys Fluent ◽  
Flow Parameters ◽  
3D Geometry ◽  
Flow Through ◽  
Original Part ◽  
Scr System

The article presents the results of experimental research and their comparison with CFD simulations for the original selective catalytic reduction system and WALKER replacement. The research was performed to develop the WALKER universal mixer. The SCR prototype without mixer and with the proposed mixer were tested and compared with the original VW part. The next step was reverse engineering, which consisted in scanning the tested parts with a laser and processing their point cloud in Leios2 program. Reverse engineering has allowed the reconstruction of 3D geometry of the tested parts in the Catia v5 program and then preparation their models for computational fluid dynamics. Numerical simulations were carried out in the Ansys Fluent program, thanks to which several quantities were determined e.g. uniformity index of gas flow through the monolith and coefficient of variation as a measure of mixing degree, which have a significant impact on the design of the mixer and the SCR system.

scholarly journals Comparison of results of experimental research with numerical calculations of a model one-sided seal

2015 ◽  
Vol 36 (2) ◽  
pp. 61-74 ◽  
Author(s):  
Damian Joachimiak ◽  
Piotr Krzyślak
Keyword(s):  
Experimental Research ◽  
Static Pressure ◽  
Measurement Data ◽  
Labyrinth Seal ◽  
Numerical Calculations ◽  
Steam Turbines ◽  
Flow Conditions ◽  
Numerical Research ◽  
Model Segment ◽  
Selection Of

AbstractPaper presents the results of experimental and numerical research of a model segment of a labyrinth seal for a different wear level. The analysis covers the extent of leakage and distribution of static pressure in the seal chambers and the planes upstream and downstream of the segment. The measurement data have been compared with the results of numerical calculations obtained using commercial software. Based on the flow conditions occurring in the area subjected to calculations, the size of the mesh defined by parameter y+has been analyzed and the selection of the turbulence model has been described. The numerical calculations were based on the measurable thermodynamic parameters in the seal segments of steam turbines. The work contains a comparison of the mass flow and distribution of static pressure in the seal chambers obtained during the measurement and calculated numerically in a model segment of the seal of different level of wear.

scholarly journals HEAT TRANSFER AND FRICTION IN CHANNELS OF MARINE GAS TURBINE POWER PLANTS UNDER CHANGING DYNAMICS OF INCREASING WORKING MEDIUM TEMPERATURE

2018 ◽  
pp. 50-57
Author(s):  
Yuri Gorjanovich Volodin ◽  
Mikhail Yurievich Khramov ◽  
Yury Ivanovich Matveev
Keyword(s):  
Heat Transfer ◽  
Friction Coefficient ◽  
Power Plants ◽  
Gas Flow ◽  
Local Heating ◽  
Mutual Effect ◽  
Initial Section ◽  
Heat Emission ◽  
Medium Temperature ◽  
Working Medium

He article presents the results of the experimental research of non-stationary effects and the influence of transiency caused by burst heating of the gas flow on values of local coefficients of friction and heat emission on the initial section of the cylindrical channel. The main reason of destruction of the main engine is local heating of some elements, i.e. the process of heat-transfer that occurs outside the combustion chamber in fire tubes, where at the entrance of turbine generates heated gas flow in non-isothermal environment. This heated gas flow rotates the turbine. Kinematic and heat structures of this gas flow at the studied period of time undergo the mutual effect of destabilizing factors, such as non-isothermal effect of the longitudinal pressure gradient caused by the uprising of the dynamic and heat transiency. Friction coefficient Cf and coefficient of heat losses St are the most important criteria of the gas flow, which characterize gas dynamics and heat exchange of the gas flow. Non-stationarity has an essential effect on the values of friction coefficient and heat loss coefficient, which increase or decrease in 2.0-2.5 times, compared to their quasisteady analogues. Beyond non-stationary process, when the temperature of working body becomes stationary, the key role is played by the thermal head which causes laminarization phenomenon of the of the heat turbulent boundary layer.

Electroslag refining with liquid metal for composite rotor manufacturing

2018 ◽  
Vol 2 (91) ◽  
pp. 49-55
Author(s):  
L. Medovar ◽  
G. Polishko ◽  
G. Stovpchenko ◽  
V. Kostin ◽  
A. Tunik ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Transition Zone ◽  
Power Plants ◽  
Uniform Structure ◽  
Steam Turbines ◽  
Heavy Weight ◽  
Heat Treated ◽  
Working Medium ◽  
Steel Grades ◽  
Available Technology

Purpose: To develop novel ESR based process for composite ingot with shallow transition zone between layers in order to produce efficient heavy-weight rotors for steam turbines. Design/methodology/approach: The nowadays heavy-weight rotors for steam turbines for power plants are monoblock or two or more layer in length composite part facilitating operation in different zones withstanding various loads and working medium. However, the joining of various steel in composite rotors by welding has low productivity. The ESR now is recognised as the best available technology for the big-diameter and mass forgings for power generating machines, including rotor ones. The ESR affords the most favourable conditions of solidification resulting in homogenous low-segregation ingot with smooth surface and high-quality structure. The step ahead is the ESR for composite. Findings: The two-layer model ingot had produced from steel grades 12Cr13 and 35NiCrMoV12-5 were manufactured using the electroslag process with the liquid metal (ESR LM) in the CSM of 180 mm in diameter with ingot withdrawing. The transition zone in two-layer ingot had have the shallow shape and low depth with the even macrostructure without defects of the same type as both joined steels. The metal of the transition zone fully satisfies standard requirements for properties of both steel grades in the heat treated and as-cast conditions. Research limitations/implications: The ESR LM can provide both the monobloc heavy ingots with uniform structure and composites with low-stress connection between metal layers for heavyweight rotors and other critical products manufacturing.

Improving the efficiency and reliability of electric power generation at incineration plants

2020 ◽  
Vol 12 (4) ◽  
pp. 281-285
Author(s):  
A. V. Martynov ◽  
N. E. Kutko
Keyword(s):  
Low Temperature ◽  
Power Plants ◽  
Thermal Power ◽  
Moscow Region ◽  
Capital Costs ◽  
Working Medium ◽  
The Creation ◽  
Working Media ◽  
Near Future ◽  
Efficiency And Reliability

The article deals with the problem of waste disposal and, accordingly, landfills in the Moscow Region, which have now become the number 1 problem for the environment in Moscow and the Moscow Region. To solve this problem, incineration plants (IP) will be established in the near future. 4 plants will be located in the Moscow Region that will be able to eliminate 2800 thousand tons of waste per year. Burning of waste results in formation of slag making 25% of its volume, which has a very high temperature (1300.1500°C). An arrangement is considered, in which slag is sent to a water bath and heats the water to 50.90°C. This temperature is sufficient to evaporate any low-temperature substance (freons, limiting hydrocarbons, etc.), whereupon the steam of the low-temperature working medium is sent to a turbine, which produces additional electricity. The creation of a low-temperature thermal power plant (TPP) increases the reliability of electricity generation at the IP. The operation of low-temperature TPPs due to the heat of slag is very efficient, their efficiency factor being as high as 40.60%. In addition to the efficiency of TPPs, capital costs for the creation of additional devices at the IP are of great importance. Thermal power plants operating on slag are just such additional devices, so it is necessary to minimize the capital costs of their creation. In addition to equipment for the operation of TPPs, it is necessary to have a working medium in an amount determined by calculations. From the wide variety of working media, which are considered in the article, it is necessary to choose the substance with the lowest cost.

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