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Evaluation of Performance and Emission Characteristics of Lean Combustion with High Energy Spark Ignition
Energy and Power , 2011, DOI: 10.5923/j.ep.20110101.04
Abstract: The effect of ignition energy on lean operation of lean burn engines is currently being investigated. All previous engine investigations have presented results on relatively quiescent combustion induced turbulence and entrainment of the mixture into the plasma jet substantially. This improves the lean operating capability. The objective of the present investigations is to investigate the performance, combustion characteristics and emission levels of high energy, breaker- less, transistorized coil ignition system with surface discharge extended electrodes. A comparison is also made with that of a lower energy conventional system with normal spark plug and extended electrode plug.
Techno-economic evaluation of oxy-combustion coal-fired power plants
Jie Xiong,HaiBo Zhao,ChuGuang Zheng
Chinese Science Bulletin , 2011, DOI: 10.1007/s11434-011-4707-5
Abstract: Increasing attention is being paid to the oxy-combustion technique of coal-fired power plants because CO2 produced from fossil fuel combustion can be captured and sequestrated by it. However, there are many questions about the economic properties of the oxy-combustion technique. In this paper, a detailed techno-economic evaluation study was performed on three typical power plants (2 × 300 MW subcritical, 2 × 600 MW supercritical, 2 × 1000 MW ultra supercritical), as conventional air fired and oxycombustion options in China, by utilizing the authoritative data published in 2010 for the design of coal-fired power plants. Techno-economic evaluation models were set up and costs of electricity generation, CO2 avoidance costs as well as CO2 capture costs, were calculated. Moreover, the effects of CO2 tax and CO2 sale price on the economic characteristics of oxy-combustion power plants were also considered. Finally, a sensitivity analysis for parameters such as coal sample, coal price, air separation unit price, flue gas treatment unit price, CO2 capture efficiency, as well as the air excess factor was conducted. The results revealed that: (1) because the oxy-combustion technique has advantages in thermal efficiency, desulfurization efficiency and denitration efficiency, oxy-combustion power plants will reach the economic properties of conventional air fired power plants if, (a) the CO2 emission is taxed and the high purity CO2 product can be sold, or (b) there are some policy preferences in financing and coal price for oxy-combustion power plants, or (c) the power consumption and cost of air separation units and flue gas treatment units can be reduced; (2) from subcritical plants to supercritical and finally ultra-supercritical plants, the economics are improving, regardless of whether they are conventional air fired power plants or oxy-combustion power plants.
Comprehensive evaluation of municipal sewage sludge combustion characteristics and its combustion kinetics model in Guangzhou
广州城市污泥燃烧性能综合评价及其燃烧动力学模型

LIU Jingyong,SUN Shuiyu,
刘敬勇
,孙水裕

环境科学学报 , 2012,
Abstract: Five municipal sewage sludges, KFQ, DTS, LJ, LD and ZZ, from different sources of Guangzhou city and one sewage sludge sample ZQ from Zhaoqing city were collected. The six dried single samples and one mixtures were investigated by a thermogravimetric method analysis (TGA) under different conditions and four combustion indexes of sludge were calculated by using the TG-DTG curves. The results showed that the original municipal sewage sludge was with the characteristics of high volatile mater, low content of fixed carbon and low calorific value. The whole combustion process can be divided into four stages including the water releasing stage, volatile releasing stage, volatile combustion stage and fixed carbon combustion stage. Obvious, differences were discovered from different sludges at the same TG-DTG curves. The volatile separating and combustion dominated the whole combustion process. The combustion characteristics of different sources of sludge were dependent on the wastewater treatment process, the sources of sludge and their physical and chemical properties. The LJ sludge combustion performance was the best while the LD sludge was worst in the six kinds of sludge according to the volatile releasing index D, flammability index C and the comprehensive combustion index S. The index values of KFQ and ZZ mixtures became low except for the volatile releasing index D. The heating rate of the mixture was too fast, therefore cannot significantly improve the overall sludge combustion. Both the combustion reaction equation during different combustion periods and the corresponding kinetics parameter E were calculated by the Coats-Redfern equation. The results indicated that the value of activation energy (E) was corresponded with the combustion stages.
Thermal Analysis of Combustion Engine in Accordance to Temperature at the Outside Surfaces of the Engine
Zbigniew J. Sroka
Open Access Library Journal (OALib Journal) , 2014, DOI: 10.4236/oalib.1100816
Abstract: The internal combustion engine needs to be assessed in terms of thermal loads that come from different sources. Thermal analysis is important in both the design and the evaluation of the conditions of the engine. Interesting good results are obtained by association studies using non-invasive methods such as Infrared and mathematical modelling based on the boundary conditions identified in the experiment. The paper presents a methodology for measuring the surface temperature fields outside of the engine and the mathematical evaluation. The collected material will in future give opportunity to study dynamic thermal states based on the technique of reverse engineering.
Evaluation of Biofield Energy Treatment on Physical and Thermal Characteristics of Selenium Powder
Mahendra Kumar Trivedi, Rama Mohan Tallapragada, Alice Branton, Dahryn Trivedi, Gopal Nayak, Omprakash Latiyal, Snehasis Jana
Journal of Food and Nutrition Sciences , 2015, DOI: 10.11648/j.jfns.20150306.14
Abstract: Selenium (Se) is an essential trace element, and its deficiency in the humans leads to increase the risk of various diseases, such as cancer and heart diseases. The objective of this study was to investigate the influence of biofield energy treatment on the physical and thermal properties of the selenium powder. The selenium powder was divided into two parts denoted as control and treated. The Control part was remained as untreated and treated part received Mr. Trivedi’s biofield energy treatment. Both control and treated selenium samples were characterized using x-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis – differential thermal analysis (TGA-DTA), and Fourier transform infrared spectroscopy (FT-IR). The XRD data showed that biofield energy treatment has slightly altered the lattice parameter (0.07%), unit cell volume (0.15%), density (-0.14%), atomic weight (0.15%), and nuclear charge per unit volume (-0.21%) in the treated selenium powder as compared to the control. The crystallite size of the treated selenium powder was reduced considerably from 106.98 nm (control) to 47.55 nm. The thermal analysis study showed that the latent heat of fusion was 64.61 J/g in the control, which changed to 68.98, 52.70, 49.71 and 72.47 J/g in the treated T1, T2, T3, and T4 samples respectively. However, the melting temperature did not show any considerable change in the treated selenium samples as compared to the control. The FT-IR spectra showed the absorption peak at 526 and 461 cm-1, which corresponding to metal oxide bonding vibration in the control and treated selenium powder respectively. Hence, overall data suggest that, the biofield energy treatment considerably altered the physical and thermal properties of selenium powder. Therefore, biofield energy treatment could make selenium even more useful nutrient in human body.
Thermal radiation in combustion systems
Pessoa-Filho, José Bezerra;
Journal of the Brazilian Society of Mechanical Sciences , 1999, DOI: 10.1590/S0100-73861999000300014
Abstract: a numerical procedure for solving the nongray radiative transfer equation (rte) in two-dimensional cylindrical participating media is presented. nongray effects are treated by using a narrow-band approach. radiative emission from co, co2, h2o, ch4 and soot is considered. the solution procedure is applied to study radiative heat transfer in a premixed ch4-o2, laminar, flame. temperature, soot and ir-active species molar fraction distributions are allowed to vary in the axial direction of the flame. from the obtained results it is possible to quantify the radiative loss in the flame, as well as the importance of soot radiation as compared to gaseous radiation. since the solution procedure is developed for a two-dimensional cylindrical geometry, it can be applied to other combustion systems such as furnaces, internal combustion engines, liquid and solid propellant combustion.
Thermal radiation in combustion systems  [cached]
Pessoa-Filho José Bezerra
Journal of the Brazilian Society of Mechanical Sciences , 1999,
Abstract: A numerical procedure for solving the nongray radiative transfer equation (RTE) in two-dimensional cylindrical participating media is presented. Nongray effects are treated by using a narrow-band approach. Radiative emission from CO, CO2, H2O, CH4 and soot is considered. The solution procedure is applied to study radiative heat transfer in a premixed CH4-O2, laminar, flame. Temperature, soot and IR-active species molar fraction distributions are allowed to vary in the axial direction of the flame. From the obtained results it is possible to quantify the radiative loss in the flame, as well as the importance of soot radiation as compared to gaseous radiation. Since the solution procedure is developed for a two-dimensional cylindrical geometry, it can be applied to other combustion systems such as furnaces, internal combustion engines, liquid and solid propellant combustion.
Combustion Characteristics of Tree Woods  [PDF]
Suryakant Chakradhari, Khageshwar Singh Patel
Journal of Sustainable Bioenergy Systems (JSBS) , 2016, DOI: 10.4236/jsbs.2016.62004
Abstract: Biomass is a renewable energy source because sun energy is stored in the form of biomass which regrows over a relatively short period as compared to fossil fuel. The biomass on burning released energy with emission of carbon dioxide, volatile organic compounds, particulate matters and ash residue. The combustion characteristics of biomass depends on several factors of plants i.e. bulk density, moisture, organic matter and metal content. In this work, the combustion characteristics i.e. heat value, moisture, volatile matter and ash content as well as emission fluxes of particulate matters (PM10) of trees grown in central India are described. The calorific value (CV) of 53 trees was ranged from 5190 - 8130 kcal/kg with mean value (p = 0.05) of 6380 ± 170 kcal/kg. Bahera tree showed the highest CV, 8130 kcal/kg, and hence, it was chosen for the detailed studies.
Yield at Thermal Engines Internal Combustion  [PDF]
Relly Victoria V. Petrescu, Raffaella Aversa, Bilal Akash, Ronald B. Bucinell, Juan M. Corchado, Filippo Berto, MirMilad Mirsayar, John Kaiser Calautit, Antonio Apicella and Florian Ion T. Petrescu
American Journal of Engineering and Applied Sciences , 2017, DOI: 10.3844/ajeassp.2017.243.251
Abstract: The paper presents an algorithm to set the parameters of the dynamics of the classic mechanism the main of internal combustion. It shows the distribution of the forces (on the main mechanism of the engine) on engines with internal combustion. With these strong points and together with speeds of kinematic couplings shall be determined when the output of the engine heat shield. The method shall be applied separately for two distinct situations: When the engine is working on a compressor and in the system of the engine. For the two individual cases, two independent formulae are obtained for the efficiency of the engine. With these relations is then calculated with respect to the mechanical efficiency of the engine heat shield Otto, in four-stroke, for two-stroke engines and 4 stroke V. the final yield of the engine is obtained taking into account and thermal efficiency given by the Cycle Carnot program.
EMISSION AND COMBUSTION CHARACTERISTICS OF DIFFERENT FUELS IN A HCCI ENGINE  [PDF]
S.Mohanamurugan,S. Sendilvelan
International Journal of Automotive and Mechanical Engineering , 2011,
Abstract: Different intake valve timings and fuel injection amounts were tested in order to identify their effects on exhaust emissions and combustion characteristics using variable valve actuation (VVA) in a Homogeneous Charge Compression Ignition (HCCI) engine. The HCCI engine is a promising concept for future automobile engines and stationary power plants. The two-stage ignition process in a HCCI engine creates advanced ignition and stratified combustion, which makes the ignition timing and combustion rate controllable. Meanwhile, the periphery of the fuel-rich zone leads to fierce burning, which results in slightly high NOx emissions. The experiments were conducted in a modified single cylinder water-cooled diesel engine. In this experiment we use diesel, bio-diesel (Jatropha) and gasoline as the fuel at different mixing ratios. HCCI has advantages in high thermal efficiency and low emissions and could possibly become a promising combustion method in internal combustion engines.
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