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COB334 BANCO DE TRABAJO 2D PARA EL DESARROLLO DE SUB-MODELOS DE MOTORES DE ENCENDIDO POR CHISPA
Gino Bella & S Cordiner
Dipartimento de Ingegneria Meccanica Universita di Roma "Tor Vergata" Via della Ricerca Scientifica 00133 Roma Italia, E-mail: bella@utovrm.it
Gabriel Defranco
Laboratorio de Máquinas Térmicas, Facultad de Ingeniería U.N.L.P, Av. 1 y 47 La Plata 1900 Argentina,
E-mail: ghdefran@volta.ing.unlp.edu.ar
A 2D finite volume model has been developed as a workbench for sub-models development for combustion, turbulence and wall interaction in spark ignition engines combustion modeling. In particular different formulation of the eddy break-up model for turbulent premixed combustion have been casted in the 2D framework in conjuction with standard k-epsilon and k-epsilon-RNG turbulence models formulation. The simplified 2D formulation results particularly suited for model assessment. Numerical results have been then compared with experimental results varying the basic operational parameter (i.e. air/fuel ratio and RPM) . In cylinder pressure data have been recorded for a 1242 Fiat MPI engine in different operating conditions. Pressure data and calculated heat release rate have been compared with numerical predictions. Even in the 2D simplified approach results seem to be on good accordance with the experiments and the the fundamental behaviour of the combustion model is correctly described.
Keywords: motor de combustión interna - modelo multidimensional de simulación de motor - modelo turbulento - motor de encendido por chispa - análisis decombustion
COB337 SISTEMA PARA MEJORAR LAS CARACTERISTICAS DE ARRANQUE DE LOS MOTORES DIESEL EN LA ALTURA
Guillermo Lira Cacho, Nicolai Patrakhalsev & Jorge Ponce G.
Sección de Posgrado, Facultad de Ingeniería Mecánica - Universidad Nacional de Ingeniería
Av. Túpac Amaru 210 - Rímac, Lima-Perú - E-mail: master_fim@uni.edu.pe
Se presentan los fundamentos teóricos de un sistema para mejorar el arranque de los motores diesel en la altura, que incluye una válvula especial, denominada RND, utilizada para introducir líquidos inflamables a la línea de alta presión del sistema de inyección, y así reducir el período de retraso del encendido durante el arranque. Complementariamente, se propone el método de desconexión parcial de cilindros para evitar que el motor se apague después de arrancar. También, se presentan los resultados experimentales del tiempo de arranque, utilizando líquidos inflamables, en un banco de pruebas con simulación de altura estrangulando la admisión.
Keywords: Arranque en frío, altura, período de retraso del encendido, velocidad crítica, válvula RND, desconexión de cilindros, líquidos inflamables.
COB518 IDENTIFICAÇÃO DE DETONAÇÃO EM MOTORES DE COMBUSTÃO INTERNA - PROCEDIMENTO EXPERIMENTAL
Luiz C.D. Arboés, Alessandro B.de S. Oliveira, Fernando J.R. Neves & João N.S. Vianna
Departamento de Engenharia Mecânica - Faculdade de Tecnologia - UnB
CEP 70910-900 Brasília - Brasil E-mail : aless@serpens.enm.unb.br
This work presents the results of tests aimed at developing a methodology for the correct identification and analysis of knocking in internal combustion engines during laboratory testing. The instrumentation layout, and test methods used are presented, as well as the results obtained for gasoline engines of different capacities. The objectives of the tests included the identification of block vibration frequencies caused by knocking, the determination of the optimum position on the engine block for the knock sensor, and the analysis of the influence of engine speed and ignition advance on the intensity of knocking.
Keywords: Motores, Detonação, Sensores, Vibração, Pressão
COB727 SOBRE A ESCOLHA DE SISTEMA DE CONTROLE DO VETOR EMPUXO DE MOTORES FOGUETE A PROPELENTE LÍQUIDO / ON THE CHOOSE OF THE THRUST VECTOR CONTROL SYSTEM OF LIQUID PROPELLANT ROCKET ENGINES
Alexandr Alexandrovich Kozlov, Toshiaki Yoshino, Adalberto Pacífico Comiran, Mário Niwa
Divisão de Propulsão -- CTA-IAE
CEP 12228-904 São José dos campos, Brasil
This paper describes an analysis on the suitability of different types of thrust vector control (TVC) system to be applied to liquid rocket engines of open cycle scheme. It provides description of different types of existing Russian engines and the TVC methods that is utilized in these systems. In particular, detailed analysis is conducted on the propulsion system using liquid oxigen/kerosene propellants on three different open cycle configurations, aiming the second stage of VLS-2 launcher. These configurations are: a) one turbopump feeding four fixed combustion chambers, with the attitude control forces provided by four vernier nozzles expelling gases from the turbine; b) one turbopump feeding four fixed combustion chambers, with the control forces provided by four gimballing combustion chambers feeded by independent turbopump; and c) four autonomous gimballing engines, each one having its own turbopump and combustion chamber.
Keywords: propulsão líquida, motor foguete, controle de atitude, controle do vetor empuxo, veículo lançador
liquid propulsion, rocket engine, attitude control, thrust vector control, launch vehicle
COB728 EXPERIMENTOS BÁSICOS SOBRE MOTOR FOGUETE A PROPELENTE LÍQUIDO / BASIC EXPERIMENTS ON LIQUID PROPELLANT ROCKET ENGINE
Mário Niwa, Marco Aurélio da Cunha Alves, Carlos Roberto Arantes Vieira & Roberto dos Passos Vidal
Instituto de Aeronáutica e Espaço, Centro Técnico Aeroespacial, IAE/CTA
CEP 12228-904 São José dos Campos, SP, Brasil -- E-mail: niwa@iconet.com.br
The use of the technology of liquid propellant rocket-engine in the next phase of the Brazilian Space Program is a need. This technology includes complex and multidisciplinary nature problems, still new for our country. Considering the broad variety of required specialization, more researchers from industries, universities and research centers should be devoting their efforts to related fields for the success of the Program. Fundamental studies on injectors and atomization, ignition, combustion of spray, combustion under high pressure environment, are some of the fields that need to be conducted more extensively. In this work, an assembly of simple conception, composed by a test module and a small engine, was constructed and tested, in order to demonstrate a practical way to perform basic studies. The preliminary results show that the assembly is operational and allows to conduct several kind of experiments.
Keywords: Propulsão líquida / liquid propulsion, motor foguete / rocket-engine, propelente líquido / liquid propellant, combustão de spray / combustion of spray.
COB729 PROPULSÃO LÍQUIDA NO BRASIL / LIQUID PROPULSION IN BRAZIL
Mário Niwa & Toshiaki Yoshino
Instituto de Aeronáutica e Espaço, Centro Técnico Aeroespacial, IAE/CTA
CEP 12.228-904 São José dos Campos, Brasil - E-mail: niwa@iconet.com.br
The knowledge already accumulated on technology of solid propellant rocket-engine allows Brazil to develop propulsion systems for small launch vehicles. To obtain commercially feasible class vehicles however, the inclusion of stages with liquid propellant rocket-engine becomes a necessary condition. It is a complex technology that involves long-term big volume investment. Therefore, initial planning should be carefully prepared in order to direct the development activities in an effective way. In this work, it is intended to give contribution in this direction, analyzing some fundamental aspects for assimilating the new technology. Initially, main advantages and disadvantages that each of propulsion systems, liquid and solid, adds in a vehicle are discussed. Finally, configuration options for the next Brazilian Launch Vehicle are discussed for directing the activities for capability development.
Keywords: Propulsão líquida / liquid propulsion, motor foguete / rocket-engine, propelente líquido / liquid propellant, propelente sólido / solid propellant
COB903 CONFIGURAÇÃO DE SISTEMAS DE COGERAÇÃO CONSIDERANDO A SENSIBILIDADE DO INDICADOR DE VIABILIDADE / CONFIGURATION OF COGENERATION SYSTEMS CONSIDERING THE VIABILITY INDICATOR SENSIBILITY
André Ramon Silva Martins & Luiz Augusto Horta Nogueira
Departamento de Engenharia Mecânica, Escola Federal de Engenharia de Itajubá - EFEI - Itajubá
CEP 37.500-000 Itajubá, Brasil - E-mail: amartins@iee.efei.rmg.br
Cogeneration has been appointed as an important alternative to supply the increasing demand of electricity in Brazil. Even tough this technology presents high thermodynamic efficiency, not always is economically merited, depending basically on the load factor and fuels and electrical energy prices. So it is worthwhile to develop good analysis tools for feasibility studies. In this paper one presents a improved methodology to evaluate the pay-back time of industrial cogeneration plants, determining the energy balance through convolution of thermal and electrical load curves and allowing to estimate the economic indicator in two scenarios. The difference of pay-back time in these scenarios can be used as risk indicator of a particular cogeneration configuration, assisting the decisor to select the proper capacity and best level of supplementary heat to be adopted.
Keywords: Cogeração, Modelagem Térmica, Otimização de sistemas Térmicos. / Cogeneration, Thermal Modelling , Thermal Systems Optimisation
COB1100 A METHOD FOR CALCULATION OF FORCES ACTING ON THE GAS TURBINE BLADES WITH FILM AND EFUSION COOLING
Vojin Grkovic
Faculty of Technical Sciences, P.O.Box 55, 21121 Novi Sad, Yugoslavia, Fax No. (+)381 21 350775
Main technical solutions for air cooling gas turbines blades are shortly described in the paper. The analytical procedure, based on the certain assumptions, for calculation of whirl and axial forces acting on blades with film and effusion cooling is given in detail. The analogous procedures for calculation of torque and power are also presented. The procedures are based on the impulse law and on the specific properties of the cooling process and blade surface. The consequences of film and/or effusion cooling on velocity diagram are presented and discussed in detail. For a blade with effusion cooling and for a blade with film cooling are given exemplified calculation of tangential and axial forces. The consequences of film and effusion cooling on the degree of reaction are also analyzed and the results are presented. We can generally conclude that, under introduced assumptions, there is small, but important increase of moment and forces due to film and effusion cooling, compared to no cooled blades.
Keywords: Gas turbines, Cooling of gas turbine blades, Force on gas turbine blade.
COB1146 COMBUSTION CHAMBERS FOR SPARK IGNITION ENGINES FUELED WITH NATURAL GAS
Fernando L. J. de Castro
Departamento de Engenharia Mecânica, Escola Politécnica - USP, CEP 05508-900 São Paulo, SP, Brasil - e-mail: flcastro@usp.br
Robert L. Evans
Department of Mechanical Engineering, Faculty of Applied Sciences - UBC, 2324 Main Mall, Vancouver, B.C. - V6T 1Z4 - Canada
E-mail: evans@mech.ubc.ca
This paper describes a new four-valve cylinder head for the Ricardo Hydra research engine. This cylinder head was built for a research project on the new combustion chambers for heavy duty spark ignition engines operating on natural gas, conducted at the Department of Mechanical Engineering, University of British Columbia, Canada. The new four-valve cylinder head will allow the determination of the optimum level of turbulence inside the combustion chamber, which originates from intake-generated swirl and tumble gas motion and their effects on the combustion process in engines fueled with natural gas.
The results of research on the optimization of a "fast, lean-burn" combustion system for spark-ignited natural gas engines that meet emission regulations without the use of exhaust gas clean-up equipment are also presented. A family of "squish-jet" pistons was developed and tested over a wide range of air-fuel ratios using full-load operating conditions; these results are also presented and discussed.
Keywords: four-valve cylinder head, squish-jet chambers, spark ignition engines
COB1274 DESIGN OF A RETROFIT FOR HEAVY DUTY DIESEL ENGINES TO LIMIT PARTICULATE MATTER EMISSIONS
A.F. Romero López, G. Arámbula Cosío, G. Hernández Bautista, J. Teutle García, R. Pech. Departamento de Mecánica, Térmica y Fluidos, Instituto de Ingeniería, UNAM 04510 México D.F.,
Tel. : (5) 622-8142 Fax (5) 616-2894 e-mail : afrl@servidor.unam.mx
A preliminary design of a Diesel particles filter system for heavy duty vehicles is presented. The system consists of two ceramic catalyzed filters connected in parallel, so that is possible to regenerate one of them while the other is in operation. The regeneration (cleaning) process is carried out through the injection of a hot air flow in inverse direction to the filtering process. The air is heated by a thermal energy storage device (Thermal Inertia Device, TID). The system has a control and monitoring electronic circuit based on a micro-controller.
Keywords: Regeneration, Monitoring, Diesel Particulate Filtering, TID
COB1300 POWER GENERATION SYSTEMS USING FLUIDIZED BED COMBUSTION AND GASIFICATION
Nikolai Khartchenko
Institute for Energy Engineering, Technical University of Berlin.
Marchstr. 18, 10587 Berlin, Germany - E-mail: nik@buran.fb10.tu-berlin.de
The two types of pressurized fluidized bed combustors (PFBC), the bubbling PFBC and the circulating PCFBC plants, are now undergoing further development with the aim to increase efficiency, reduce emissions, improve availability, and thus to facilitate the commercialization of this technology. This paper reviews the progress and highlights the problems in the development of hybrid cycle power plants based on pressurized fluidized bed combustion and gasification. Hybrid cycle power plants show significant improvement in energy conversion efficiency, and essential reduction in SO2 and NOx emissions. They have higher efficiency than integrated gasification combined-cycle power plants. The second generation PFBC coal plants target 50 % efficiency.
Keywords: Pressurized fluidized bed combustor, hybrid cycle power plant, HGCU, emissions control
COB1301 NOx-EMISSIONS CONTROL TECHNIQUES FOR COAL-FUELED POWER PLANTS AND GAS TURBINE-BASED COMBINED CYCLES
Nikolai Khartchenko
Institute for Energy Engineering, Technical University of Berlin.
Marchstr. 18, 10587 Berlin, Germany - E-mail: nik@buran.fb10.tu-berlin.de
Advanced techniques for NOx-emissions control used in coal-fueled power plants and gas turbine-based combined cycles are discussed. The in-furnace NOx control reduces the NOx formation or emissions during combustion by using staged combustion, reburning, flue gas recirculation, low NOx burners (LNBs), and other methods. The NOx emissions reduction in the range of 40 to 60% is achieved with LNBs, 20 to 25% with the burners-out-of-service method, 15 to 25% by using overfire air, up to 15% due to low excess air, and 5% by biased firing. In addition, the paper discusses multi-pollutant emissions control methods. The recently developed processes for simultaneous SO2/NOx removal feature high removal efficiency for the two pollutant species. Thus, in the SNOx-process 96% SO2 and 94% NOx removal is achieved when burning coal with 3.4% sulfur.
Keywords: In-furnace NOx reduction, staged combustion, reburning, multi-pollutant emissions control, low NOx burners.
COB1430 ANÁLISE TÉRMICA E ECONÔMICA DE TURBINA A GÁS DE CICLO ÚMIDO/ THERMAL AND ECONOMIC ANALYSIS OF THE HUMID AIR TURBINE CYCLE
Marcos Vinicius Ribeiro Franco, Marco Antônio R. Nascimento & Luiz A. Horta Nogueira
Escola Federal de Engenharia de Itajubá- EFEI, Av. B.P.S. 1300, Itajubá, MG, CEP 37500-000 - E - mail: marco@iem.efei.rmg.br
This work presents thermodynamics simulation and economic analysis of the Humid Air Turbine cycle (HAT) operation. In this cycle hot water from intercooler and recuperator is mixed with air from the compressors in the evaporator, it is then sent to the gas turbine combustion chamber and expanded along with the combustion gases. A computer program was developed to simulate the thermodynamics behaviour on design point given by the specific fuel consumption, thermal efficiency and specific net work as function of turbine entry temperature and overall pressure ratio. After thermodynamics simulation, an economic analysis was carried out for power plant of 30MW with fuel cost of 3,5 US$/GJ, which presented energy generation cost as a function of the load factor of power plant for different interest rate and design philosophy. The return rate of investment has been calculated taking into account to sell energy at 60 US$/MWh. The economic parameters have indicated that economic viability of the investment, in scenery where electric energy cost is sold, is over 60 US$/MWh. In addition, the results of the HAT have been compered to those of Simple Cycle, Combined Cycle, Steam Injected Gas Turbine and Intercooled Steam Injected Gas Turbine.
Keywords: Thermal Power System, the Humid Air Turbine cycle, Economic Analysis of Thermal System,
Ciclos de potência, Ciclos HAT, Análise Econômica de Sistemas de Potência
COB1431 ANALYSIS AND DIAGNOSIS OF THE OPERATION PERFORMANCES OF A STEAM POWER PLANT
Andrea Lazzaretto1, Alarico Macor1, Alberto Mirandola1, Anna Stoppato1 & Franco Donatini2
1Department of Mechanical Engineering, University of Padova - via Venezia, 1
35131 Padova, Italy - E-mail: mira@ dim.unipd.it
2 ENEL S.p.A. - Thermal Research Center - via Andrea Pisano, 120 - 56122 Pisa, Italy
A new exergetic and exergoeconomic method for the diagnosis of energy systems operation is presented and discussed. The calculation of suitable indicators, showing the deviations of the fuel consumption from the expected one, helps the analyst or the operator identify the machines or the devices responsible for the malfunction and those "victims" of the malfunction itself. The method, applied to a big-size steam power plant, proved to be useful in locating the origin of malfunctions and their effects on the overall performances; anyhow, it is shown that some experience is needed by the operator, because the results must be interpreted in the light of both the knowledge of the plant operation and the theoretic bases of the diagnostic procedure suggested by the authors.
Keywords: On line diagnosis, exergy analysis, exergoeconomic analysis, computer code
COB1432 PERFORMANCE AND GAS-DYNAMICS OF PROPULSION SYSTEMS WITH A SEPARATE SOURCE OF ENERGY
Fernando de Souza Costa & João Andrade de Carvalho Jr.
Laboratório Associado de Combustão e Propulsão - LCP/INPE, CEP 12630-000, Cx. Postal 01, Cachoeira Paulista, SP, Brazil
E-mail: fernando@yabae.cptec.inpe.br
A new improved approach is developed to analyze alternative propulsion systems with an additional power source, such as augmented catalytic, nuclear and electrical propulsion systems. The performance characteristics are calculated in terms of time of flight, power density, characteristic velocities and specific impulses. The effects of propellant density, tankage weight and the stagnation enthalpy of propellants are considered. A simplified model of the thruster gas-dynamics is employed to determine the mass flow rates and the power input to the propellant.
Keywords: Electrical Propulsion, Nuclear Propulsion, Performance, Gas-Dynamics, Mass Efficiency