scholarly journals Design and working performance study of a novel micro parallel plate combustor with two nozzles for micro thermophotovotaic system

2015 ◽  
Vol 19 (6) ◽  
pp. 2185-2194
Author(s):  
J.F. Pan ◽  
Z.Y. Hou ◽  
Y.X. Liu ◽  
A.K. Tang ◽  
J. Zhou ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Parallel Plate ◽  
Combustion Process ◽  
Three Dimensional ◽  
Volumetric Flow Rate ◽  
Combustion Efficiency ◽  
Performance Study ◽  
Power Generators ◽  
Inlet Angle ◽  
Micro Combustor

Micro-combustors are a key component in combustion-driven micro power generators, and their performance is significantly affected by their structure. For the application of micro-thermophotovoltaic (MTPV) system, a high and uniform temperature distribution along the walls of the micro combustor is desired. In this paper, a three-dimensional numerical simulation has been conducted on a new-designed parallel plate micro combustor with two nozzles. The flow field and the combustion process in the micro combustor, and the temperature distribution on the wall as well as the combustion efficiency were obtained. The effects of various parameters such as the inlet angle and the fuel volumetric flow rate on the performance of the micro combustor were studied. It was observed that a swirl formed in the center of the combustor and the radius of the swirl increased with the increase of the inlet rate, and the best working condition was achieved at the inlet angle ?=20?. The results indicated that the two-nozzle combustion chamber had a higher and more uniform mean temperature than the conventional combustor under the same condition.

scholarly journals Effects of Injector Spray Angle on Performance of an Opposed-Piston Free-Piston Engine

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3735
Author(s):  
Qinglin Zhang ◽  
Zhaoping Xu ◽  
Shuangshuang Liu ◽  
Liang Liu
Keyword(s):  
Combustion Engine ◽  
Fluid Dynamic ◽  
Combustion Process ◽  
Three Dimensional ◽  
Mixture Distribution ◽  
Combustion Efficiency ◽  
Spray Angle ◽  
Piston Engine ◽  
Free Piston ◽  
Free Piston Engine

A free-piston engine is a novel internal combustion engine which has the advantages of a variable compression ratio and multi-fuel adaptability. This paper focuses on numerical simulation for combustion process and spray angle optimization of an opposed-piston free-piston engine. The working principle and spray-guided central combustor structure of the engine are discussed. A three-dimensional computational fluid dynamic model with moving mesh is presented based on the tested piston motion of the prototype. Calculation conditions, spray models, and combustion models were set-up according to the same prototype. The effects of spray angle on fuel evaporation rate, mixture distribution, heat release rate, in-cylinder pressure, in-cylinder temperature, and emissions were simulated and analyzed in detail. The research results indicate that the performance of the engine was very sensitive to the spray angle. The combustion efficiency and the indicated thermal efficiencies of 97.5% and 39.7% were obtained as the spray angle reached 40°.

Experimental Research on Combustion and Emission Performance for Micro Combustor of MTPV System with Stratified Porous Media

2012 ◽  
Vol 608-609 ◽  
pp. 934-940
Author(s):  
Jian Wu ◽  
Bo Li ◽  
Bin Xu ◽  
Jia Xuan Miao
Keyword(s):  
Porous Media ◽  
Temperature Distribution ◽  
Band Gap ◽  
Experimental Research ◽  
Wall Temperature ◽  
Combustion Efficiency ◽  
Critical Component ◽  
Uniform Temperature ◽  
The Past ◽  
Micro Combustor

As the critical component of the system, micro-combustor requires a high and uniform temperature distribution along the wall to meet demands for the band gap of the PV cells. The past experiments have proved that the peak wall temperature of the combustor with porous media increases obviously. This paper will have a research on stratified porous media to enhance the combustion efficiency of the combustor and reduce the emissions.

scholarly journals Temperature Distribution Measurement Using the Gaussian Process Regression Method

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Huaiping Mu ◽  
Zhihong Li ◽  
Xueyao Wang ◽  
Shi Liu
Keyword(s):  
Temperature Distribution ◽  
Gaussian Process ◽  
Real World ◽  
Combustion Process ◽  
Three Dimensional ◽  
Prediction Method ◽  
Gaussian Process Regression ◽  
Regression Method ◽  
Pollutant Emission ◽  
Temperature Distributions

The temperature distribution in real-world industrial environments is often in a three-dimensional space, and developing a reliable method to predict such volumetric information is beneficial for the combustion diagnosis, the understandings of the complicated physical and chemical mechanisms behind the combustion process, the increase of the system efficiency, and the reduction of the pollutant emission. In accordance with the machine learning theory, in this paper, a new methodology is proposed to predict three-dimensional temperature distribution from the limited number of the scattered measurement data. The proposed prediction method includes two key phases. In the first phase, traditional technologies are employed to measure the scattered temperature data in a large-scale three-dimensional area. In the second phase, the Gaussian process regression method, with obvious superiorities, including satisfactory generalization ability, high robustness, and low computational complexity, is developed to predict three-dimensional temperature distributions. Numerical simulations and experimental results from a real-world three-dimensional combustion process indicate that the proposed prediction method is effective and robust, holds a good adaptability to cope with complicated, nonlinear, and high-dimensional problems, and can accurately predict three-dimensional temperature distributions under a relatively low sampling ratio. As a result, a practicable and effective method is introduced for three-dimensional temperature distribution.

Development of Micro-Turbo Charger and Micro-Combustor as Feasibility Studies of Three-Dimensional Gas Turbine at Micro-Scale

2003 ◽  
Author(s):  
Kousuke Isomura ◽  
Motohide Murayama ◽  
Hiroshi Yamaguchi ◽  
Nobuaki Ijichi ◽  
Nobuyoshi Saji ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Three Dimensional ◽  
Feasibility Studies ◽  
Combustion Efficiency ◽  
Micro Scale ◽  
Performance Change ◽  
Turbo Charger ◽  
Component Efficiency ◽  
Micro Combustor ◽  
Current Stage

A gas turbine at micro-scale is under development at Tohoku University in conjunction with Ishikawajima-Harima Heavy Industries Co., Ltd. (IHI). The development of the engine is currently at the stage of experimentally proving the component performance required to realize the Brayton cycle. The component tests are split into two activities at current stage to separate the effect of the heat transfer from the combustor to the compressor, which was shown to have large effect on the component efficiency, by previous studies. Current objective of the tests is to clarify whether the gas turbine at micro-scale is feasible from the point of performance change due to the scaling effect. A micro-turbocharger has been developed to prove the performance of the compressor and the bearing. It has been started operating and the micro-turbocharger tests are currently underway. Micro-combustors have been developed to find the appropriate configuration of the micromachine gas turbine. It has successfully been designed and tested to achieve 99.9% of combustion efficiency with both Hydrogen and Methane fuel.

Performance Study of Thermoelectric Power Generators at Different Geometrical Configurations

2021 ◽  
Author(s):  
Mohamed M. Elsabahy ◽  
Ramy Rabie ◽  
Mahmoud Ahmed
Keyword(s):  
Performance Enhancement ◽  
Three Dimensional ◽  
Numerical Data ◽  
Working Environment ◽  
Manufacturing Cost ◽  
Performance Study ◽  
Thermo Electric ◽  
Cross Sectional ◽  
Power Generators ◽  
Wide Range

Abstract The thermoelectric generator (TEG) output power is mainly dependent on physical characteristics, dimensions, leg configuration, number of p-n thermocouples, and other parameters. Therefore, identifying the optimal leg configuration that attains the best performance is essential. The present work considers several leg configurations by the volume reduction of the conventional prism leg, without changing the shape class via decreasing basic dimensions (i.e. leg height or cross-sectional area) and with morphing the original prism into X and trapezoidal shapes. A three-dimensional thermo-electric model is developed to investigate the performance of TEG legs at the uni-thermocouple level. Besides, to determine the reliability of the proposed configurations, a wide range of thermal boundary conditions are applied on the hot side to resemble the realistic working environment that TEG might experience at room temperature on the cold side with natural convective cooling. The model is numerically simulated after being validated with the available experimental and numerical data. The comparison indicates that decreasing leg height adversely affects the TEG performance, whereas a significant enhancement in the performance is achieved (in order) for X, trapezoidal and reduced area shapes. However, the performance enhancement, i.e. power and efficiency, associated with the simple reduced area configuration is relatively close to those achieved by X or trapezoidal ones, raising many questions in terms of simplicity and manufacturing cost. The performed research further deepens our understanding of TEG performance enhancement via optimizing legs’ attributes at uni-thermocouple as a single building block of the full-size TEG module.

Experimental and Numerical Analysis of a Motorcycle Air Intake System Aerodynamics and Performance

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
M. A. Abd Halim ◽  
N. A. R. Nik Mohd ◽  
M. N. Mohd Nasir ◽  
M. N. Dahalan
Keyword(s):  
Combustion Process ◽  
Three Dimensional ◽  
Engine Performance ◽  
Internal Flow ◽  
Rapid Expansion ◽  
Navier Stokes ◽  
Turbulent Fluctuation ◽  
Ansys Fluent ◽  
Induction System ◽  
Acceleration And Deceleration

Induction system or also known as the breathing system is a sub-component of the internal combustion system that supplies clean air for the combustion process. A good design of the induction system would be able to supply the air with adequate pressure, temperature and density for the combustion process to optimizing the engine performance. The induction system has an internal flow problem with a geometry that has rapid expansion or diverging and converging sections that may lead to sudden acceleration and deceleration of flow, flow separation and cause excessive turbulent fluctuation in the system. The aerodynamic performance of these induction systems influences the pressure drop effect and thus the engine performance. Therefore, in this work, the aerodynamics of motorcycle induction systems is to be investigated for a range of Cubic Feet per Minute (CFM). A three-dimensional simulation of the flow inside a generic 4-stroke motorcycle airbox were done using Reynolds-Averaged Navier Stokes (RANS) Computational Fluid Dynamics (CFD) solver in ANSYS Fluent version 11. The simulation results are validated by an experimental study performed using a flow bench. The study shows that the difference of the validation is 1.54% in average at the total pressure outlet. A potential improvement to the system have been observed and can be done to suit motorsports applications.

scholarly journals Combustion Optimization for Coal Fired Power Plant Boilers Based on Improved Distributed ELM and Distributed PSO

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1036 ◽  
Author(s):  
Xinying Xu ◽  
Qi Chen ◽  
Mifeng Ren ◽  
Lan Cheng ◽  
Jun Xie
Keyword(s):  
Power Plant ◽  
Combustion Process ◽  
Optimization Method ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Combustion Model ◽  
Nox Emissions ◽  
Coupling Characteristics ◽  
Learning Machine ◽  
Combustion Optimization

Increasing the combustion efficiency of power plant boilers and reducing pollutant emissions are important for energy conservation and environmental protection. The power plant boiler combustion process is a complex multi-input/multi-output system, with a high degree of nonlinearity and strong coupling characteristics. It is necessary to optimize the boiler combustion model by means of artificial intelligence methods. However, the traditional intelligent algorithms cannot deal effectively with the massive and high dimensional power station data. In this paper, a distributed combustion optimization method for boilers is proposed. The MapReduce programming framework is used to parallelize the proposed algorithm model and improve its ability to deal with big data. An improved distributed extreme learning machine is used to establish the combustion system model aiming at boiler combustion efficiency and NOx emission. The distributed particle swarm optimization algorithm based on MapReduce is used to optimize the input parameters of boiler combustion model, and weighted coefficient method is used to solve the multi-objective optimization problem (boiler combustion efficiency and NOx emissions). According to the experimental analysis, the results show that the method can optimize the boiler combustion efficiency and NOx emissions by combining different weight coefficients as needed.

Boundary Condition Design to Heat a Moving Object at Uniform Transient Temperature Using Inverse Formulation

2004 ◽  
Vol 126 (3) ◽  
pp. 619-626 ◽  
Author(s):  
Hakan Ertu¨rk ◽  
Ofodike A. Ezekoye ◽  
John R. Howell
Keyword(s):  
Boundary Condition ◽  
Temperature Distribution ◽  
Design Problem ◽  
Manufacturing Industry ◽  
Three Dimensional ◽  
Chemical Deposition ◽  
Iterative Solution ◽  
Conveyor Belt ◽  
Temperature History ◽  
Transient Temperature

The boundary condition design of a three-dimensional furnace that heats an object moving along a conveyor belt of an assembly line is considered. A furnace of this type can be used by the manufacturing industry for applications such as industrial baking, curing of paint, annealing or manufacturing through chemical deposition. The object that is to be heated moves along the furnace as it is heated following a specified temperature history. The spatial temperature distribution on the object is kept isothermal through the whole process. The temperature distribution of the heaters of the furnace should be changed as the object moves so that the specified temperature history can be satisfied. The design problem is transient where a series of inverse problems are solved. The process furnace considered is in the shape of a rectangular tunnel where the heaters are located on the top and the design object moves along the bottom. The inverse design approach is used for the solution, which is advantageous over a traditional trial-and-error solution where an iterative solution is required for every position as the object moves. The inverse formulation of the design problem is ill-posed and involves a set of Fredholm equations of the first kind. The use of advanced solvers that are able to regularize the resulting system is essential. These include the conjugate gradient method, the truncated singular value decomposition or Tikhonov regularization, rather than an ordinary solver, like Gauss-Seidel or Gauss elimination.

scholarly journals Combustion Thermodynamics of Ethanol, n-Heptane, and n-Butanol in a Rapid Compression Machine with a Dual Direct Injection (DDI) Supply System

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2729
Author(s):  
Ireneusz Pielecha ◽  
Sławomir Wierzbicki ◽  
Maciej Sidorowicz ◽  
Dariusz Pietras
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Direct Injection ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Injection System ◽  
Rapid Compression Machine ◽  
Process Indicators ◽  
Rapid Compression

The development of internal combustion engines involves various new solutions, one of which is the use of dual-fuel systems. The diversity of technological solutions being developed determines the efficiency of such systems, as well as the possibility of reducing the emission of carbon dioxide and exhaust components into the atmosphere. An innovative double direct injection system was used as a method for forming a mixture in the combustion chamber. The tests were carried out with the use of gasoline, ethanol, n-heptane, and n-butanol during combustion in a model test engine—the rapid compression machine (RCM). The analyzed combustion process indicators included the cylinder pressure, pressure increase rate, heat release rate, and heat release value. Optical tests of the combustion process made it possible to analyze the flame development in the observed area of the combustion chamber. The conducted research and analyses resulted in the observation that it is possible to control the excess air ratio in the direct vicinity of the spark plug just before ignition. Such possibilities occur as a result of the properties of the injected fuels, which include different amounts of air required for their stoichiometric combustion. The studies of the combustion process have shown that the combustible mixtures consisting of gasoline with another fuel are characterized by greater combustion efficiency than the mixtures composed of only a single fuel type, and that the influence of the type of fuel used is significant for the combustion process and its indicator values.

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