Advanced Aerodynamic Sealing System for Thermo Turbo Machinery

2003 ◽  
Author(s):  
Karl E. Uth ◽  
Edward G. Dong
Keyword(s):  
Electric Power ◽  
New Technologies ◽  
Aerospace Industry ◽  
Pollutant Emissions ◽  
Steam Turbines ◽  
Labyrinth Seals ◽  
Turbo Machinery

This paper presents the feasibility of using advanced aerodynamic sealing systems to replace aged labyrinth seals in gas & steam turbines for the electric power generating and aerospace industry. Focus is on promoting new technologies in the power generating industry to reduce pollutant emissions.

Numerical Analysis of Honeycomb Labyrinth Seals: Cell Geometry and Fin Tip Thickness Impact on the Discharge Coefficient

2015 ◽  
Author(s):  
Alessio Desando ◽  
Andrea Rapisarda ◽  
Elena Campagnoli ◽  
Roberto Taurino
Keyword(s):  
Discharge Coefficient ◽  
New Technologies ◽  
Pressure Ratio ◽  
Labyrinth Seal ◽  
Pollutant Emissions ◽  
Cell Diameter ◽  
Labyrinth Seals ◽  
Cell Pattern ◽  
Divergent Flow ◽  
Impact Reduction

The design of the newest aircraft propulsion systems is focused on environmental impact reduction. Extensive research is being carried out with the purpose of improving engine efficiency, enhancing crucial features, in order to decrease both fuel consumption and pollutant emissions. A lot of improvements to fulfill these objectives must be made, focusing on the optimization of the main engine parts through the utilization of new technologies. The leakage flow reduction in the turbo machinery rotor-stator interaction is one of the main topics to which numerous efforts are being devoted. Labyrinth seals, widely employed in the aerospace field thanks to their simple assembly process and maintenance, can be the means to achieve these objectives. This paper mainly focuses on the optimization of the labyrinth seal stator part, characterized, in modern Low Pressure Turbines (LPT), by a honeycomb cell pattern. The first phase of this study deals with the implementation and validation of a Computational Fluid Dynamics (CFD) numerical model, by using the experimental data available in the literature. Discharge coefficients obtained by numerical simulations, performed at different clearances and pressure ratios on both smooth and honeycomb non-rotating labyrinth seals, are presented and compared to the literature data. Then, for both convergent and divergent flow conditions, the effects on the discharge coefficient due to variations in several cell pattern parameters (i.e. cell diameter, depth and wall thickness) and fin tip thickness are shown. For these analyses the values of clearance and pressure ratio are set at a constant value.

Discussion on “An investigation as to the most economical vacuum in electric power stations employing steam turbines and cooling towers”

1910 ◽  
Vol 44 (201) ◽  
pp. 687-688
Author(s):  
J.A. Robertson ◽  
G.L. Black ◽  
S.A. Simon ◽  
W.B. Sayers ◽  
M.G.S. Swallow ◽  
...  
Keyword(s):  
Electric Power ◽  
Cooling Towers ◽  
Steam Turbines ◽  
Power Stations

scholarly journals Numerical Analysis on Steam Exciting Force Caused by Rotor Eccentricity

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
L. H. Cao ◽  
J. X. Wang ◽  
P. Li ◽  
P. F. Hu ◽  
Y. Li
Keyword(s):  
Pressure Fluctuation ◽  
Exciting Force ◽  
Width Ratio ◽  
Leakage Flow ◽  
Steam Turbines ◽  
Labyrinth Seals ◽  
Full Circle ◽  
Exciting Vibration ◽  
Numerical Simulator ◽  
Main Factor

The steam exciting force has been proved to be great threat to the operation safety of steam turbines. The mechanism of steam exciting vibration cannot be profoundly revealed by simply analyzing the steam exciting force, especially in simplified models. Therefore, a full-circle stage of steam turbine with shroud and labyrinth seals was investigated by numerical simulator CFX. The instability of leakage flow and the pressure fluctuation were analyzed on the eccentric condition. The effects of leakage vortexes, the depth-width ratio of seal cavity, and the eccentricity on the steam exciting force were studied. Results show that the leakage flow is nonuniform in the circumferential direction with the change of front teeth vortexes, which causes the steam exciting force. The tangential and radial steam exciting force both increase with the eccentricity increasing. The effects of the depth-width ratio of seal cavity on the two forces are different. In addition, the pressure fluctuation caused by the leakage vortexes on the shroud surfaces is a main factor inducing the steam exciting force. This research provides a theoretical guidance for the operation safety and optimization of steam turbines.

scholarly journals THE USE OF HYBRID VEHICLES AS A PROPOSAL FOR REDUCING CO2 EMISSIONS AND ITS CONTRIBUTION TO REDUCING GREENHOUSE GAS EMISSIONS

2009 ◽  
Vol 8 (1) ◽  
pp. 07
Author(s):  
C. A. R. De Carvalho ◽  
W. Q. Lamas
Keyword(s):  
Carbon Dioxide ◽  
Energy Consumption ◽  
Fossil Fuels ◽  
Climate Changes ◽  
New Technologies ◽  
New Technology ◽  
Hybrid Vehicles ◽  
Pollutant Emissions ◽  
Gas Emissions ◽  
Global Concern

The problems related to energy consumption and pollutant emissions for thetransport sector represent a major global concern regarding climate changes caused by greenhouse gases, directly related to the increased level of gas emissions from fossil fuels , the main one being carbon dioxide. One way tominimize this problem is through the introduction of new technologies. Hybrid cars are one of the new technology options that has the main advantage of reducing fuel consumption and therefore reducing the amount of CO2 in the atmosphere. This paper gives an introduction to hybrid vehicles, with the aim of presenting their main advantages and evaluate their impact on emissions of CO2 in the Brazilian fleet, compared to conventional vehicles.

scholarly journals Copper Oxide-Based Photocatalysts and Photocathodes: Fundamentals and Recent Advances

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7271
Author(s):  
Tomasz Baran ◽  
Alberto Visibile ◽  
Michael Busch ◽  
Xiufang He ◽  
Szymon Wojtyla ◽  
...  
Keyword(s):  
New Technologies ◽  
Low Cost ◽  
Renewable Energy Sources ◽  
Co2 Reduction ◽  
Chemical Properties ◽  
Water Electrolysis ◽  
Pollutant Emissions ◽  
Low Toxicity ◽  
Abundant Element ◽  
Direct Use

This work aims at reviewing the most impactful results obtained on the development of Cu-based photocathodes. The need of a sustainable exploitation of renewable energy sources and the parallel request of reducing pollutant emissions in airborne streams and in waters call for new technologies based on the use of efficient, abundant, low-toxicity and low-cost materials. Photoelectrochemical devices that adopts abundant element-based photoelectrodes might respond to these requests being an enabling technology for the direct use of sunlight to the production of energy fuels form water electrolysis (H2) and CO2 reduction (to alcohols, light hydrocarbons), as well as for the degradation of pollutants. This review analyses the physical chemical properties of Cu2O (and CuO) and the possible strategies to tune them (doping, lattice strain). Combining Cu with other elements in multinary oxides or in composite photoelectrodes is also discussed in detail. Finally, a short overview on the possible applications of these materials is presented.

scholarly journals Prospects of using new technologies in Russia’s electric power industry to comply with international commitments to reduce CO2 emissions

2018 ◽  
Vol 58 ◽  
pp. 03007
Author(s):  
Alexey Tchemezov ◽  
Elena Chemezova ◽  
Anton Syromyatnikov
Keyword(s):  
Electric Power ◽  
Power Plants ◽  
New Technologies ◽  
Thermal Power ◽  
Electric Power Industry ◽  
Power Industry ◽  
International Commitments ◽  
Russian Region ◽  
Emission Of Greenhouse Gases

This study addresses the methodology of projecting the electric power industry developments, taking into account environmental constraints. I obtained quantitative assessments of long-term electric power industry development in a Russian region, determined the emission of greenhouse gases from fuel combustion at thermal power plants (TPPs), and the efficiency of technologies to reduce greenhouse gas emissions in the electric power industry.

Leakage and Cavity Pressures in an Interlocking Labyrinth Gas Seal: Measurements vs. Predictions

2019 ◽  
Author(s):  
Luis San Andrés ◽  
Tingcheng Wu ◽  
Jose Barajas-Rivera ◽  
Jiaxin Zhang ◽  
Rimpei Kawashita
Keyword(s):  
Mass Flow ◽  
Pressure Ratio ◽  
Labyrinth Seal ◽  
Secondary Flows ◽  
Tip Clearance ◽  
Inlet Pressure ◽  
Steam Turbines ◽  
Rotor Speed ◽  
Labyrinth Seals ◽  
Gas Seals

Abstract Gas labyrinth seals (LS) restrict secondary flows (leakage) in turbomachinery and their impact on the efficiency and rotordynamic stability of high-pressure compressors and steam turbines can hardly be overstated. Amongst seal types, the interlocking labyrinth seal (ILS), having teeth on both the rotor and on the stator, is able to reduce leakage up to 30% compared to other LSs with either all teeth on the rotor or all teeth on the stator. This paper introduces a revamped facility to test gas seals for their rotordynamic performance and presents measurements of the leakage and cavity pressures in a five teeth ILS. The seal with overall length/diameter L/D = 0.3 and small tip clearance Cr/D = 0.00133 is supplied with air at T = 298 K and increasing inlet pressure Pin = 0.3 MPa ∼ 1.3 MPa, while the exit pressure/inlet pressure ratio PR = Pout/Pin is set to range from 0.3 to 0.8. The rotor speed varies from null to 10 krpm (79 m/s max. surface speed). During the tests, instrumentation records the seal mass flow (ṁ) and static pressure in each cavity. In parallel, a bulk-flow model (BFM) and a computational fluid dynamics (CFD) analysis predict the flow field and deliver the same performance characteristics, namely leakage and cavity pressures. Both measurements and predictions agree closely (within 5%) and demonstrate the seal mass flow rate is independent of rotor speed. A modified flow factor Φ¯=m.T/PinD1-PR2 characterizes best the seal mass flow with a unique magnitude for all pressure conditions, Pin and PR.

Thermodynamic Assessment of Hybrid PSOFC/GT Systems for Mechanical/Electric Power Generation

2000 ◽  
Author(s):  
K. K. Botros ◽  
G. R. Price ◽  
R. Parker
Keyword(s):  
Power Generation ◽  
Electric Power ◽  
Gas Turbine ◽  
Life Cycle Cost ◽  
Pressure Ratio ◽  
Pollutant Emissions ◽  
Mechanical Power ◽  
Total Power ◽  
Specific Work ◽  
System Pressure

Hybrid PSOFC/GT cycles consisting of pressurized solid oxide fuel cells integrated into gas turbine cycles are emerging as a major new power generation concept. These hybrid cycles can potentially offer thermal efficiencies exceeding 70% along with significant reductions in greenhouse gas and NOX emissions. This paper considers the PSOFC/GT cycle in terms of electrical and mechanical power generation with particular focus on gas pipeline companies interested in diversifying their assets into distributed electric generation or lowering pollutant emissions while more efficiently transporting natural gas. By replacing the conventional GT combustion chamber with an internally reformed PSOFC, electrical power is generated as a by-product while hot gases exiting the fuel cell are diverted into the gas turbine for mechanical power. A simple one-dimensional thermodynamic model of a generic PSOFC/GT cycle has shown that overall thermal efficiencies of 65% are attainable, whilst almost tripling the specific work (i.e. energy per unit mass of air). The main finding of this paper is that the amount of electric power generated ranges from 60–80% of the total power available depending on factors such as the system pressure ratio and degree of supplementary firing before the gas turbine. Ultimately, the best cycle should be based on the “balance of plant”, which considers factors such as life cycle cost analysis, business and market focus, and environmental emission issues.

scholarly journals Gaseous Pollutants and Particulate Matter (PM) in Ambient Air and the Number of New Cases of Type 1 Diabetes in Children and Adolescents in the Pomeranian Voivodeship, Poland

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Małgorzata Michalska ◽  
Katarzyna Zorena ◽  
Piotr Wąż ◽  
Maria Bartoszewicz ◽  
Agnieszka Brandt-Varma ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Particulate Matter ◽  
New Technologies ◽  
Renewable Energy Sources ◽  
Ambient Air ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Gaseous Pollutants ◽  
High Exposure

The increase in type 1 diabetes mellitus (T1DM) incidence in children is worrying and not yet fully explored. It is suggested that probably air pollution exposure could contribute to the development of T1DM. The aim of the study was to investigate the relationship between the concentration of gaseous pollutants including, nitrogen dioxide (NO2), nitric oxides (NOx), sulphur dioxide (SO2), carbon monoxide (CO), and particulate matter (PM) in the air, and the number of new cases of T1DM in children. The number of new cases of T1DM was obtained from the Clinic of Paediatrics, Diabetology, and Endocrinology, Medical University of Gdańsk. The number of children of 0–18 years old in Pomeranian Voivodeship was acquired from the Statistical Yearbook. The concentrations of PM10 absorbance, NO2, NOx, SO2, and CO were measured at 41 measuring posts, between 1 January 2015 and 31 December 2016. It was detected that the average annual concentration of PM10 was higher than the value acceptable to the WHO. Furthermore, the average 24-hour concentration of PM10 was 92 μg/m3 and was higher compared to the acceptable value of 50 μg/m3 (acc. to EU and WHO). Moreover, the number of new cases of T1DM showed a correlation with the annual average concentration of PM10 (β = 2.396, p<0.001), SO2 (β = 2.294, p<0.001), and CO (β = 2.452, p<0.001). High exposure to gaseous pollutants and particulate matter in ambient air may be one of the factors contributing to the risk of developing T1DM in children. Therefore, it is important to take action to decrease air pollutant emissions in Poland. It is crucial to gradually but consistently eliminate the use of solid fuels, such as coal and wood in households, in favour of natural gas and electricity. The development of new technologies to improve air quality, such as “best available techniques” (BAT) or renewable energy sources (water, wind, and solar generation) is of critical importance as well.

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