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Experimental Tests on a Pre-Heated Combustion Chamber for Ultra Micro Gas Turbine Device: Air/Fuel Ratio Evaluation  [PDF]
Roberto Capata, Kliton Kylykbashi, Alfonso Calabria, Mario Di Veroli
Engineering (ENG) , 2016, DOI: 10.4236/eng.2016.811071
Abstract: Current portable power generators are mainly based on internal combustion engine since they present higher values of efficiency comparing to other engines; the main reason why internal combustion engine is not convenient for micro power generation (5 - 30 kW) is because of their heaviness. Micro and ultra micro gas turbine devices, based on a micro compressor and a micro turbine installed on the same shaft, are more suitable for this scope for several reasons. Micro turbine systems have many advantages over reciprocating engine generators, such as higher power density (with respect to size and weight), extremely low emissions and few, or just one, moving part. Those designed with foil bearings and air-cooling operate without oil, coolants or other hazardous materials. Micro turbines also have the advantage of having the majority of their waste heat contained in their relatively high temperature exhaust. Micro turbines offer several potential advantages compared to other technologies for small-scale power generation, including: a small number of moving parts, compact size, lightweight, greater efficiency, lower emissions, lower electricity costs, and opportunities to utilize waste fuels. The object of this study is the experimental tests on a stand-alone gas turbine device with a pre-heated combustion chamber (CC), to validate the fuel consumption reduction, compared to an actual and commercial device, used on air models.
MODELLING AND PARAMETRIC STUDY OF GAS TURBINE COMBUSTION CHAMBER  [PDF]
M. Sadrameli,M. Jafari
International Journal of Advances in Engineering and Technology , 2012,
Abstract: In order to find the amount of pollution created by combustion in a gas turbine, Conjugate CFD equations in turbulent mixing and combustion equations is done.Overall conservation equations for mass, momentum, energy and the combustion process, for large eddy simulation (LES) and the chemical reaction rate method is merged. For the numerical solution, solving the Structured Grid with the Staggered Grid and cylindrical coordinates is considered. Discretization equations used for grid capability and QUICK algorithm to solve the equations and the numerical algorithm is performed. To verify the numerical solution, the geometry of the boundary conditions of a gas turbine combustor controlled by analytical and experimental results, it turns out that the numerical solution has been considered. Compared with existing analytical models and experimental results with acceptable error has been approved. NO production output of combustion in a gas turbine based on variables such as changes in temperature and the amount of fuel and air entering the gas turbine power optimization has been found.
DEVELOPING OF A NEW COMPREHENSIVE SPARK IGNITION ENGINES CODE FOR HEAT LOSS ANALYSIS WITHIN COMBUSTION CHAMBER WALLS  [cached]
Shahram Khalilarya,Mohammad Javadzadeh
Thermal Science , 2010, DOI: tsci10041013k
Abstract: The objective of this work is to develop the existing a zero-dimensional model named ODES to provide detailed insights into the internal process of the modern high speed spark ignition engines. Therefore, it has been concentrated on the development of new sub models for incorporation in an extended form of ODES, as follows: - the existing semi-empirical combustion model has been replaced by a new comprehensive model, which is based on the turbulent flame speed in the combustion chamber. - the existing three wall heat transfer model has been replaced by a new one in which, the combustion chamber is divided in to three zones including cylinder head, cylinder wall, and piston head. The steady-state heat transfer equation is solved through finite difference method with replaced boundary and initial conditions. The results gave the temperature distribution of combustion chamber walls. The rate of heat losses from combustion chamber to the coolant is calculated by using the mean temperature of each part. The code has been extensively validated with respect to performance and heat transfer against experimental results obtained on XU7JP spark ignition engine with two kinds of fuel, gasoline and compresed natural gas and gave good agreement with available experimental.
A swirler stabilized combustion chamber for a micro-gas turbine fuelled with natural gas
Krieger, Guenther C.;Campos, André P. V. de;Sacomano Filho, Fernando L.;Souza, Rafael C. de;
Journal of the Brazilian Society of Mechanical Sciences and Engineering , 2012, DOI: 10.1590/S1678-58782012000400004
Abstract: micro-gas turbines are a good alternative for on-site power generation, since their operation is very reliable. the possibility of operating with various fuels increases versatility and, as a result, the usage of these devices. focusing on a performance improvement of a tri-fuel low-cost micro-gas turbine, this work presents investigations of the inner flow of its combustion chamber. the aim of this analysis was the characterization of the flame structure by the temperature field of the chamber inner flow. the chamber was fuelled with natural gas. in the current chamber, a swirler and a reversed flow configuration were utilized to provide flame stabilization. the inner flow investigations were done with numerical analysis, which were compared to experimental data. the analysis of the inner flow was done with numerical simulations, which used the rsm turbulence model. a β-pdf equilibrium model was adopted to account for the turbulent combustion process. different models of heat transfer were compared. thermal radiation and specially heat conduction in the liner walls played significant roles on results.
Analysis of Re Influence on MILD Combustion of Gas Turbine  [PDF]
Lijun Wang, Dongdong Qi, Xiaowei Sui, Xin Xie
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.54B018
Abstract: The paper numerical studied the MILD(Moderate or Intense Low-oxygen Dilution) combustion mode and performances in the designed gas turbine chamber. The influence of air jet Re number on flue gas recycles ratio Kv and hereby on kerosene fuel MILD combustion were modeled. For fixed equivalence ratio, increasing the air jet Re number to the Kv value of 3.3 - 3.8, MILD combustion mode will be formed. It has MILD combustion performances of volume combustion, excellent outlet temperature field and very low pollutant emissions. Combustor confinement has little effects on MILD combustion. Calculating results agree with other’s similar experimental data.
МОДЕЛЮВАННЯ МЕХАН ЗМУ АВТОКОЛИВАНЬ ТИСКУ ПРИ В БРАЦ ЙНОМУ ГОР НН В НИЗЬКОЕМ С ЙНИХ КАМЕРАХ ЗГОРЯННЯ ГАЗОТУРБ ННИХ УСТАНОВОК Simulation mechanism oscillations pressure vibration burning in low emission combustion chamber gas-turbine units Моделирование механизма автоколебаний давления при вибрационн  [cached]
Е.П. Ясин?цький,М.?. Торхов,С.В. Лозня,М.Б. Нал?сний
Proceedings of National Aviation University , 2006,
Abstract: Запропоновано п дх д до математичного моделювання механ зму автоколивань тиску газу при в брац йному гор нн в низькоем с йних камерах згоряння газотурб нних установок. Mathematical modelling method of the pressure self-oscillations mechanism at vibrating burning in low emission combustion chambers of the gas-turbine units is offered. Предложен подход к математическому моделированию механизма автоколебаний давления газа при вибрационном горении в низкоэмиссионных камерах сгорания газотурбинных установок.
Hybrid Wave Engine Concept and Numerical Simulation of Engine Operation
Janusz Piechna , David Dyntar
Archive of Mechanical Engineering , 2010, DOI: 10.2478/v10180-010-0004-0
Abstract: Recent investigations of micro engines have documented the problem of low efficiency of steady compression devices [2]. As a solution, the application of unsteady processes has been proposed [1, 6, 17-20]. Closer investigations have shown the applicability of pure unsteady devices for gas compression, but it is also shown that they are practically not applicable for torque generation [21]. A new concept of the wave engine has to be developed. This paper presents such a new concept and numerical investigation of the hybrid wave engine. A hybrid wave engine combines in a single machine components realizing unsteady compression, steady expansion, and mixed unsteady and steady scavenging due to the centrifugal force action. MEMS technology requires or prefers a flat geometry. Therefore, the use of a radial type of wave compression device for air compression is proposed. A numerical, two-dimensional complete model of this device was built, and several numerical simulations of engine operations were performed. The numerical model includes the simplified model of the combustion chamber closing the flow loop between the high-pressure compressed air port and the high-pressure hot exhaust gas port. The model represents the complete flow scheme of the hybrid wave engine. A special type of turbine in radial configuration with serial flow layout is used for torque generation.
NEW QUASI-STATIONARY THERMODYNAMIC APPROACH IN THE INTERNAL BALLISTICS AND THE INTERNAL COMBUSTION ENGINES
Marian Nikolov Mutafchiev
MEST Journal , 2015, DOI: 10.12709/mest.03.03.02.10
Abstract: A new principal equation of the internal ballistics is presented herein, which is determining the temperature in the barreled firing weapons and the rocket engines with solid fuel during combustion of the charge. By this new equation it is demonstrated, that during “internal combustion” in the thermodynamic system is not enthalpy imported, but internal energy. On that basis equations, determining the temperature and pressure in the cylindrical space of a piston-type internal combustion engines during the working process, are developed. Equations, determining the average temperature in the chambers of the vane gas turbine engines are also developed. Equation, determining the temperature in the combustion chambers of rocket engines with liquid fuel is also developed. Equations for determining the pressure and temperature in the gas engine of automatic firing weapons as well as collectors of piston engines are also presented.
Numerical Simulation of Combustion and Rotor-Stator Interaction in a Turbine Combustor  [PDF]
Dragos D. Isvoranu,Paul G. A. Cizmas
International Journal of Rotating Machinery , 2003, DOI: 10.1155/s1023621x03000344
Abstract: This article presents the development of a numerical algorithm for the computation of flow and combustion in a turbine combustor. The flow and combustion are modeled by the Reynolds-averaged Navier-Stokes equations coupled with the species-conservation equations. The chemistry model used herein is a two-step, global, finite-rate combustion model for methane and combustion gases. The governing equations are written in the strong conservation form and solved using a fully implicit, finite-difference approximation. The gas dynamics and chemistry equations are fully decoupled. A correction technique has been developed to enforce the conservation of mass fractions. The numerical algorithm developed herein has been used to investigate the flow and combustion in a one-stage turbine combustor.
CFD Analysis of Flow Field inside the Expansion Chamber of Internal Combustion Engines  [PDF]
K. M. Pandey,Upendra Kumar,Subho Deb Verma
International Journal of Engineering and Advanced Technology , 2012,
Abstract: Noise is a disturbance to the human environment that is escalating at such a high rate that it will become a major threat to the quality of human lives. There are numerous effects on the human environment due to the increase in noise pollution. In the present Paper, the causes and effects of noise pollution is presented. for 15m/s considering four different models of silencer through which exhaust gas passes at different velocities in atmosphere. The analysis carried with commercial package fluent software. The design of these models was carried out using Gambit. Flow is observed at different conditions. Different parameters like turbulent kinetic energy, turbulent viscosity, turbulent dissipation rate, velocity magnitude, static pressure and dynamic pressure were analyzed. . It is seen that near the source the noise is more, it decreases with increases the distance between source and observer So it is observed that muffler is also one of the major factors for noise reduction.
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