bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Analysis of the Performances of Bonded Composite Repair with Adhesive Band in Pipeline API X65
Authors: Meriem-Benziane Madjid , Abdul-Wahab Sabah A. , Merah Nesar , Babaziane Benoauda
Published: February 2014

The technique of adhesively bonded composite patch repair has been successfully applied in pipeline of API X65 components repair and has recently been expanded to commercial pipeline industry. In the present paper, the crack growth behavior of cracked pipeline API X65 repaired with bonded composite patch was investigated. The ﬁnite element approach was applied in order to analyses the circumferential crack’s behavior repaired by a carbon-epoxy composite patch. The effects of the properties of the patch on the evolution of the stress intensity factor, according of angle crack tip, were discussed. The adhesive properties were optimized to increase the performance of the repair of structures by such reinforcement. Moreover, a relatively new method was developed to stop the external corrosion and the structurally reinforce steel pipes by external wrapping of damaged sections, using ﬁbre reinforced polymer (FRP) materials. The results indicated that the defect width around the circumference had little impact on the ultimate rupture pressure of the repaired vessel. On the other hand, it was found that the defect width around the circumference was affected by the stress state in the underlying pipe substrate.
Study on Multi-Resource and Multi-Point Emergency Scheduling Problem in Transportation Accidents for Hazardous Materials Logistics
Authors: Zhong Hui Ling , Yin Hui , Zhang Guan Xiang , Cai Wen Xue , Jing Nan
Published: February 2014

This paper considers the multi-resource and multi-point emergency scheduling problem in the hazardous materials logistics accident, and a model of scheduling and the corresponding heuristic algorithm is proposed. Based on the resource classification, the resource that needed by two or more accident points is picked up, by considering the time and cost, a timely and fair scheduling plan is obtained. Finally, a case study is presented to verify the effectiveness of the algorithm.
Analysis and Improvement on Acoustic Performance of Muffler with the Consideration of Temperature and Flow Velocity
Authors: Hu Yi Xiang , Li Shun Ming , Liu Qing
Published: February 2014

Aiming for the acoustic performance of expanded-muffler, the acoustic fields, flow field, temperature field and flow regenerated noise inside the expanded-muffler were studied. Furthermore, with the consideration of temperature and flow velocity, the influence of temperature and flow velocity on acoustic performance was obtained. Based on the research, the acoustic performance of an exhaust muffler was studied. By adjusting the structural parameters, without affecting the engine output power, the insertion loss of muffler has average increased by 5.1 dB (A).
A Launching Pattern in a Mixed Model Assembly Line
Authors: Prombanpong Suksan , Somboonsilp S.
Published: February 2014

This paper aims to sequence the production plan of a condenser unit of an air-conditioned assembly line, which is a manual assembly line. In this case there are six different models with different required production rate that must be assembled simultaneously. The assembly line consists of twenty four workstations with thirty four workers. Due to the fact that the cycle time of each condenser model is varied. Thus, it is difficult to design a launching pattern so that the production requirement of each model is exactly met at each production hour. In turn, the production demand of some models can be satisfied while other models cannot be met. In order to solve this problem, the fixed rate launching algorithm is applied and the result is considered satisfactory.
Design and Simulation of a Ka-Band Pattern Reconfigurable Microstrip Patch Antenna
Authors: Deng Zhong Liang , Moran Han
Published: February 2014

This letter presents a Ka-band(26.5GHz-40GHz) microstrip patch antenna with pattern reconfigurable characteristic. The antenna is provided with five rectangular patches and four RF MEMS (microelectromechanical systems for RF circuits) switches. The central patch and other surrounding patches are connected by the switches. By changing the states of the switches, the antenna can achieve four radiation patterns and it is designed and simulated by using Ansoft HFSS. In addition, the different states are operated at the same centre frequency of 35GHz and the gain of the main radiation direction is about 7.5dB
Computational Fluid Dynamics Modeling of the Cold Condition Characteristic in an Entrained Flow Gasifier
Authors: Wu Zhi Qiang , Wang Shu Zhong , Chen Lin , Zhao Jun , Meng Hai Yu
Published: February 2014

Entrained flow gasification technology has been attracted by gasifier researchers and companies for its wide-ranging feedstock adaptability and commercial scale availability. The optimization of the entrained flow gasifier is the critical thing for the development of entrained flow gasification technology. This paper presented a three-dimensional computational fluid dynamic (CFD) simulation for a better understanding of the cold condition flow characteristic in an entrained flow gasifier. The spraying angle, diameter and injection velocity of nozzles were found to observably affect the velocity distribution and mixing condition in the entrained flow gasifier. The numerical results could provide useful information for further research on the particle track and gasification reaction and an effective process for optimizing the gasifier and nozzle.
Preparation of CF Reinforced PPS/Graphite Conductive Composite for Bipolar Plate
Authors: Zhang Hua Yong , Yang Xiao Deng , Liu Xiao Jian , Wang Tao
Published: February 2014

A kind of carbon fiber (CF) reinforced conductive composite material with graphite powders and polyphenylene sulfide (PPS) resin powders were fabricated by the hot-pressure molding method. The influence of graphite content and CF addition on the conductivity, flexural strength and density of the composite were investigated. Took into account the performance requirement of the bipolar plate of PEMFC and economic aspect, the suitable conditions for the fabrication of bipolar plate were found: the proportion of graphite and PPS was 75/25 and the addition of CF was 2.5%(wt).
Effects of Combination of 0.02 wt % Sr and Ti on the Characteristics of AC4B Alloys Produced by Low Pressure Die Casting
Authors: Sofyan Bondan Tiara , Falah Muhammad A.
Published: February 2014

Aluminium AC4B alloy is widely used in automotive industries for various components. However, when this alloy is used to produce motorcycle cylinder head by Low Pressure Die Casting (LPDC) process, high reject rate was often found due to shrinkage, porosity and misrun. Addition of grain refiner and modifier is an alternative for this problem, through the control of solidification process that results in grain refining and microstructure modification. This study was aimed to investigate the effect of combination of 0.02 wt. % Sr modifier with variation of Ti grain refiner on the characteristics of AC4B alloy and the reject rate of cylinder head components. The Ti grain refiner was varied 0.063, 0.083 and 0.108 wt. % Ti and added at the holding furnace prior to LPDC process. A series of test was conducted including hardness test from the thin and thick regions of the part, tensile test, fluidity test, vacuum test as well as observation of microstructure by using optical microscope and Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-Ray Analysis (EDAX). The results showed that the higher the Ti content, the higher the hardness for both thin and thick areas, the lower the fluidity of the molten metal. At the maximum level of Ti of 0.108 wt. % and 0.02 wt. % Sr, the reject rate was significantly reduced from 3.59 % to 1.38 %.
The Exploration on Forming Processing Method by Multiple Sparks EDM
Authors: Wang Yan Feng
Published: February 2014

This paper introduces forming processing method by multiple spark electric sparks (EDM). This method can get more material removal rate, and reduce the power consumption.
Vacuum Inert Gas Atomisation of Cr-Mn-Ni Austenitic Steel Alloys
Authors: Dubberstein Tobias , Heller Hans Peter
Published: February 2014

The Cr-Mn-Ni austenitic steel cast alloys containing 16 wt.-% chromium, 7 wt.-% manganese and 3 to 9 wt.-% nickel are used as matrix material to manufacture TRIP-Matrix-Composite containing MgO partially stabilised ZrO2 ceramics. In the present work, these steel master alloys were atomised via a vacuum inert gas atomisation to provide fine grain sized metal powders for the assembling of TRIP-Matrix-Composite. The atomised steel powders where characterised according to their chemical composition and the d50 mass median particle size determined by a laser diffraction analyses. The surface tension of the liquid steel alloys was experimentally investigated using the maximum bubble pressure (MBP) method. The reference austenitic steel alloy (AISI 304) has the highest surface tension and the highest mass median particle size compared to the Cr-Mn-Ni steel alloys, where d50 values are lower due to lower surface tension values. Finally, it is concluded from the present investigation, that the d50 size of the atomised steel powders decreases by a decrease of surface tension values for the liquid steel alloys.
Research of Joining Graphite by Use of Active Solder
Authors: Koleňák Roman , Prach Michal
Published: February 2014

The work deals with joining of graphite with stainless steel type AISI 321 by use of active solder type Sn3Ti. Structure of active solder type Sn3Ti is composed of a tin matrix in which the Ti6Sn5 phase is uniformly precipitated and the Ti3Sn phase is non-uniformly distributed. Wettability of Sn3Ti solder was determined in 10-4 Pa vacuum, at temperatures 860, 900 and 950 °C. Wetting angle of Sn3Ti solder on graphite is reduced with increasing soldering temperature and also with prolonged dwell time at soldering temperature. Temperature exerts greater effect on reduction of wetting angle. The lowest wetting angle on graphite 23° was observed at temperature 950 °C/20 min. The lowest wetting angle, observed on steel type AISI 321, attained value 18° at temperature 860 °C/20 min. Based on the results of wettability tests, the joints of graphite with stainless steel type AISI 321 were fabricated. The reactions after soldering resulted in formation of a continuous reaction layer with 5 μm average thickness on graphite/Sn3Ti solder boundary.
A Kind of Environment-Friendly Titanium Chemical Mechanical Polish Development
Authors: Huang Fu Chuan , Su Man Rong , Tang Xing Zhong , Li Hong Jun , Lu Zhao Xia
Published: February 2014

In this paper, fuzzy AHP to select the appropriate environment-friendly chemical mechanical polishing additives, and the rational design of the polish formulation. Practical application shows that the polish has a good anti-wear, the wear properties and anti-rust properties, stable performance ，and meets the needs of the chemical mechanical polishing, the rate of biodegradation more than 80%.
Influence of Gravity and Mold Shape on Molding of Aluminum Foams
Authors: Shiomi Masanori , Fukaya Tomohiro
Published: February 2014

A molding process of aluminum foams by using a rotating mold is proposed in order to improve the mold filling and forming process for light-weight parts of vehicles. Aluminum powder mixed with a foaming agent is extruded into the mold through the die heated to a temperature higher than the melting point, and the mold is filled with the aluminum foam. When the diameter of a cylindrical mold is large, the influence of gravity is significant and the mold is not filled successfully. In the proposed molding, the aluminum foam is extruded into the rotating mold of large diameter and the volumetric ratio of foam to mold cavity is improved. However, the effect of the mold rotation on the mold filling is limited due to friction.
Kiln Process Impact of Alternative Solid Fuel Combustion in the Cement Kiln Main Burner – Mathematical Modelling and Full-Scale Experiment
Authors: Ariyaratne Wijesinghe Kaluarachchige Hiromi , Manjula Edirisinghe Vidana Pathiranage Jagath , Melaaen Morten Christian , Tokheim Lars André
Published: February 2014

Increased use of alternative fuels in cement kilns is a trend in the world. However, replacing fossil fuels like coal with different alternative fuels will give various impacts on the overall kiln process due to the fuel characteristics. Hence, it is important to know to what extent the fossil fuels can be replaced by different alternative fuels without severely changing process conditions, product quality or emissions. In the present study, a mass and energy balance for the combustion of different alternative fuels in a cement rotary kiln was developed. First, the impact of different fuel characteristics on kiln gas temperature, kiln gas flow rate and air requirement were observed by using coal (reference case), meat and bone meal (MBM), two different wood types, refuse derived fuel and a mixture of saw dust and solid hazardous waste as the primary fuel. It was found that the key process parameters depend largely on the chemical characteristics of the fuel. It appears that MBM shows quite different results from other alternative fuels investigated. Next, simulation of combustion of a mixture of coal and MBM in the main burner was carried out in three steps. The first step was combustion of replacing part of coal energy with MBM, and a reduction in kiln exhaust gas temperature compared to the coal reference case was found. In the second step, the fuel feed rate was increased in order to raise the kiln gas temperature to that of the reference case. In the third step, the fuel feed rate and the clinker production rate were changed in order to have not only the same kiln gas temperature but also to obtain the same volumetric flow rate of total exhaust gas from the precalciner as in the reference case. Around 7% of reduction in clinker production rate could be observed when replacing 48% of the coal energy input. Results from a full-scale test using the same mixture of coal and MBM verified the simulation results.
Effect of over Tempering at UHSLA Steel ARMOX 500
Authors: Barényi Igor , Lipták Peter , Vojtovič Sergej
Published: February 2014

ARMOX steels are armored steels used for protect devices and facilities against blasts and explosions. Due to this purpose the ARMOX 500 steel has excellent mechanical properties as are high hardness, tensile strength and good toughness. These properties result from specific production process finished with rolling ant then quenching and tempering. The producer of ARMOX steels recommend their secondary processing (cutting, welding, shaping) at temperatures lower than 200°C due to over tempering and degradation of mechanical properties in heat affected areas. The paper describes the mechanism and reason of this degradation including the simulation of cooling process with ARMOX 500 steel.
Molecular Dynamics Studies of Cold Welding of FCC Metallic Nanowires
Authors: Huang Pei Hsing , Wu Yi Fan
Published: February 2014

The atomistic-scale cold welding processes for metallic nanowires (NWs) are studied using embedded-atom molecular dynamics (MD) simulations. The mechanical behavior and structural evolution of the FCC metallic nanowires, including Au, Ag, and Cu materials, that experienced a mechanical stretching break and solid-phase pressure welding process, were investigated. The welding temperatures (Tw) ranging from 100 to 900 K were systemically investigated on the effects of welding strength. The ratio of welding strength, Rws, defined as the ratio between the welding strength and the original yield strength of NWs, was employed to identify the welding quality. Simulation results show that the Rws of Au NWs is better than those of Ag and Cu welded at room temperature; however, for welding at high temperatures (600~900 K) the Rws value of Ag NWs is the best. The Rws values of Au NWs using cold welding show less variance than with high temperature welding, reflecting that the application of cold-welding on the Au NWs is highly feasible. The Rws values for NWs with small diameters are generally higher than those with large diameters. The breaking places of the tensile test for the post-welded NWs didnt occur at the welding region, indicating that the broken wires can be robustly reconnected through solid-phase mechanically-assisted welding methods.
High-Frequency Electromagnetic Waves for Diesel Soot Oxidation Strategy
Authors: Abdul Karim Zainal Ambri , Mohammad Mursal Muhammad Abdul Halim , Jamlus Mohd Hanafiah Mat
Published: February 2014

Results from an experimental investigation for diesel soot oxidation strategy using high-frequency electromagnetic waves in producing metal sparks is provided in this paper. It is envisaged that the micro plasma develop by metal when subjected to high-frequency electromagnetic waves, produces heat that enables soot oxidation process. The work attempts to investigate the relationship between spark inception of metals and micro plasma temperatures at different microwaves intensity. Various metal specimens were exposed to high-frequency electromagnetic waves at different power levels at a specific duration of time. The sparks temperatures or micro plasmas produced by the metals were measured using a high-range infrared thermometer. It was found that aluminum and brass have high spark temperatures when compared to mild steel at lower microwaves power levels. However, both aluminum and brass have lower melting point temperatures than mild steel. This makes the material unsuitable for prolong exposure to high-frequency electromagnetic waves. Mild steel was found the suitable metal to be used as the spark inceptor in the soot oxidation reaction chamber.
Morphological and Magnetic Properties of Electrodeposited Ni-Ag Alloy Nanowire Arrays in Modified AAO Template
Authors: Shang Wei Zheng , Zhang Wei Guo , Wang Hong Zhi
Published: February 2014

Highly ordered Ni-Ag alloy nanowire arrays have been fabricated successfully by electrodeposition into the pores of anodic aluminum oxide (AAO). This template was prepared with modified two-step anodizing method. The scanning and transmission electron microscopy were utilized to characterize the Ni-Ag alloy nanowire arrays. The results revealed that the nanowire arrays were regularly arranged, about 90nm in diameter and 30µm in length. The nanowires were single crystal and the atomic ratio of Ni and Ag is very close to 79:21. Magnetic hysteresis loop showed that Ni-Ag alloy nanowire arrays embedded in AAO have superparamagnetism, indicating their potential applications in biomedical materials.
The Effect of Cutting Speed on the Machinability of 2080 Special K Steel on Vertical Machining Center
Authors: Altin Abdullah
Published: February 2014

This study presents the results of machining tests carried out determine the effect of cutting forces and surface roughness on machininig of 2080 Special K (1.2080 DINX210Cr12) cold work steel in terms of cutting speed, feed rate and depth of cut for milling process. A series of experiments have been performed on 2080 Special K steel material of cutting width 50 mm with round uncoated cemented carbide insert on 5,5 Kw engine power Jhonford VMC550 CNC vertical machining center without cutting fluid. Experiments were carried out by using four different cutting speeds (70,90,110,130 m/min) at constant depth of cut (1mm) and feed rate (0,3mm/rev.) and the effects of cutting speeds on primary cutting force and surface roughness were investigated. The study of the influence of workpiece material on milling process shows that hardening of material increased by machining up. Cutting force (Fc) and surface roughness decreases with improving workpiece material machinability. From the experiments, the lowest average primary cutting force was obtained as 604,03N at cutting speed of 90m/min. The lowest average surface roughness has been obtained as 0,19 um at cutting speed 110m/min. Obtained chip form is narrow and short step.
Effect of Non-Conventional Aging Treatments on the Tensile Properties and Quality Indices of Hipped Components Made of Cast Aluminum Alloy 354
Authors: Babu G. Dinesh , Muktinutalapati Nageswara Rao
Published: February 2014

Cast aluminum alloy 354 is used extensively for production of critical automobile component, owing to its excellent castability and attractive combination of mechanical properties. With the advent of higher performance engines, there has been a steady demand to further improve the mechanical behavior of the alloy, among others, through improvements in processing. The present study explores the possibility of improving mechanical behavior and quality levels of the alloy by adopting certain non-conventional aging treatments. Quality indices Q and QC have been used for quality rating. The non-conventional treatments include aging cycles similar to T6I4 and T6I6 referred to in the published literature, artificial aging in two steps instead of in single step and artificial aging preceded by various natural aging times. The results show that none of the non-conventional treatments leads to improvement of all tensile properties compared to the standard T61 treatment. However, some specific treatments could be identified which lead to a comparable combination of tensile properties and a shade higher quality level. Increasing the time of preceding natural aging does not help in improving the tensile properties after artificial aging.
The Actual State and Prospects of a High Power Electron Beam Technology for Metallic and Non-Metallic Compositions Used in Electric Contacts and Electrodes
Authors: Miedzinski Bogdan , Habrych Marcin , Grechanyuk Ivan N. , Grechanyuk Nickolay I. , Minakova Rimma V. , Xu Liang Jun
Published: February 2014

In the paper the actual state and prospects of applicability of a high power electron beam technology for manufacturing metallic as well as nonmetallic composite materials mostly for electric contacts and electrodes are presented and discussed
Formation of Super-Hydrophobic Surface by Accumulating Pollution on RTV Silicone Rubber Coating Surface
Authors: Zhao Yue Ju , Wang Guo Gang , Zhang Jin Ling , Wang Jian Hui
Published: February 2014

The Super-hydrophobic surface can be obtained easily by pollution accumulation on room temperature vulcanized (RTV) silicone rubber coating surface. The photos taken by digital camera show that the amount of pollution on the RTV coating surface was increased with time, and after one year, the RTV coating surface nearly could hardly be seen. The water state contact angle (CA) measurement, which was investigated by the static contact angle instrument, reveals that the CA value of RTV coating surface is increased with increasing the pollution accumulation, and in suitable amount of pollution accumulation, the super-hydrophobic surface (water contact angle of 152o and roll-off angle smaller than 5 o) was obtained. The scanning electric microscope (SEM) of RTV coating with different pollution accumulation was investigated. It shows that the continuous micro-nanobinary structure can be formed with enough dust particles on the RTV surface. The mechanism of the effect of pollution accumulation on the wetting property was analyzed, the migration of hydrophobic molecular in RTV coating onto the pollution surface and the formation of micro-nanobinary structure on the RTV coating surface have synergistic effect on the super-hydrophobic surface formation caused by the pollution accumulation.
Influence of Processing State on Recovery Stress in NiTiNb Shape Memory Alloy
Authors: Wang Er Min , Hong Qi Hu , Ni Zhi Ming , Han Jin
Published: February 2014

Self-made tension machine was used to measure the evolution of recovery stress under different processing state for NiTiNb alloy. Then, SEM was used to investigate the microstructure evolution. The results show that the range of the highest recovery stress for forged NiTiNb alloy is between 210-215MPa. Otherwise, the recovery stress level of the samples enduring cold drawing and hot rolling is basically same, which all belong to the rage of 210-220MPa. After forging, the firstly precipitated TiNi phase particles become fine, only 5-8μm. The Nb tablets in eutectic microstructure, which originally contributed between TiNi phase particles, appear spheroidization.
Effect of Temperature on the Transformation of Carbon Black into Nanotubes
Authors: Asokan Vijayshankar , Madsen Dorte , Velauthapillai Dhayalan , Myrseth Velaug , Kosinski Pawel
Published: February 2014

In this paper, successful structural transformation of carbon black (CB) into nanotubes and nanoonion like structures at relatively low temperatures in the presence of transition metal catalyst is reported. This study focuses also on the influence of the temperature on the structural transformation of CB into nanostructures. The experiments were carried out at 700°C and 1000°C in a horizontal tube furnace under N2 atmosphere. The obtained samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). It was found that increase in the synthesis temperature from 700°C to 1000°C influences the morphology of the produced nanotubes significantly and the degree of crystallinity also increased with the temperature..
Effect of Carbon-Coating Morphologies on the Electrochemical Performance of Natural Graphite Spheres
Authors: Liu Shu He , Zhao Shu Chun
Published: February 2014

Similar amount of carbon with three different types of morphologies, i.e. smooth pyrolytic carbon (SPC), granular pyrolytic carbon (GPC) and carbon nanofiber (CNF) was coated on the natural graphite (NG) spheres in a fluidized bed by chemical vapor deposition (CVD) from acetylene. The effect of carbon-coating morphologies on the electrochemical performance of NG spheres were studied, the results show that: PC is more effective in improving the first coulombic efficiency (CE); both GPC and CNF can improve the cyclability, however, GPC improves the first CE whereas CNF decreases the first CE.
EDM Dressing Diamond Grinding Wheel and Recent Advances
Authors: Li Ping , Zhou Ge Qiang
Published: February 2014

There are many methods of diamond wheel dressing,broadly divided into mechanical dressing and special processing trimmed two categories.This article describes several different EDM dressing diamond grinding wheel technology and divided into two categories namely:different medium EDM dressing diamond grinding wheel and EDM assisted dressing diamond grinding wheel technology. Summarize recent wheel dressing technology research advances at home and abroad.Elaborated EDM dressing key issues to be addressed, and further research.
Solder Based Self-Assembled Structures for 3D Integration
Authors: Rao Madhav
Published: February 2014

A novel way of three dimensional (3D) chip stacking has been designed in a view to improve heat dissipation across the layers. Chip stacking using vertical interconnections forms microscale channels for coolant to circulate through the gaps. Solder-based self-assembled (SBSA) 3D structures have been designed as posts on simulated through silicon vias (TSVs) to prove the processing concept. The processing of SBSA structures using a low temperature solder alloy and dip soldering method is described. Additional processing steps to fabricate interconnected 3D structures were demonstrated. Mechanical grinding of the 3D structures shows that soldered SBSA structures were void free and robust enough to be used as a connection post for chip stacking. SBSA structures provide a solder bump that serves as a connection path in the integration of dissimilar electronic technologies. Conventional copper posts, developed in a previous project, can be an effective approach to integrated circuit (IC) stacking. However, the SBSA post provides more variety in size and shape with a potential to serve as a reservoir for solder to aid in chip bonding. The solder bumps are heat resistant and uniform thicknesses were obtained across a large array of SBSA structures. The electrical durability of SBSA posts were determined by completing I-V measurements after thermal treatments. Fabricated SBSA posts were subjected to thermal cycling with temperatures ranging from room temperature to 300 °C. The interconnected SBSA posts are shown to be stable until 165 °C with little variation in measured resistance.
Technology Forecasting of Green Energy Using Patent Analysis and Simulation Modeling
Authors: Jun Sung Hae
Published: February 2014

Green energy (GE) is natural energy that does not endanger humankind. Thus, precise knowledge about GE is very important to the future of humanity. The development of GE has been focused on renewable energy that avoids the emission of greenhouse gases. This paper proposes a technology forecasting (TF) model of GE technology that accurately explains GE. In this study, we retrieve patent documents concerning GE for application in our experiment, and we conduct patent analysis and simulation modeling in order to construct a TF model of GE technology. To verify the performance of our model, we forecast future aspects of GE technology.
Numerical Simulation of Indirectly Heated Hot Water Heater
Authors: Lenhard Richard , Kaduchová Katarína , Jandačka Jozef
Published: February 2014

This paper describes a mathematical model of heating hot water for indirectly heated hot water heater. Using the established mathematical model was carried out simulation of the device to change its geometrical parameters. Based on the results of simulations was carried out optimization of indirectly heated hot water heater for hot water. Subsequently been made CFD simulations of the device, and those were compared with a mathematical model to verify the accuracy of the proposed mathematical model of heating hot water for indirectly heated hot water heater. Computational methods based on finite volume methods (CFD method) have proved very useful in optimizing indirectly heated hot water heater.
Experimental Study on Reactivity of Limestone in FGD System
Authors: Zhang Wan Peng , Wang Mei Yan , Ma Xiu Qin , Huang Chao , Chen Fang , Jia Cheng Liang
Published: February 2014

The limestone collected from the Ji county of Tianjin was investigated in this study. The characterization of the limestone dissolution in wet FGD system is carried out by sulfuric acid titration. The results indicate that A lower PH value is benefit for the limestone dissolution, which causes high dissolution rate within short time. Smaller particle size results in higher dissolution rate. The addition of inorganic salt and organic acid significantly affect the limestone dissolution. The limestone dissolution rate increases with the increase of organic acid concentration. In all the inorganic salt, it is obvious that Na+ has an positive effect while CI- plays a negative role on the limestone dissolution. However, the addition of composite additive of adipic acid plus MgO to the limestone slurry is greatly better than using the adipic acid or MgO only.
Lightning Protection Research and Simulation of High-Speed Railway Catenary
Authors: Zheng Xue Xian , Wang Xun , Cheng Hong Bo , Cao Wen Hui
Published: February 2014

The existing high-speed railway in China is erected on the viaduct. The traction power supply system of high-speed railway consists of catenary with auto-transformer (AT). The catenary above the rails is supported by towers besides the rails. As the increase of the height from top of towers to ground, the probability of the pilot discharging of lightning to catenary will increase. And the pilot striking distance to ground always remains constant. So the horizons shielding effects for catenary will decrese, and the whole catenary naked in the atmosphere extremely easily struck by thunderbolt. In the important places, e.g., substation and areas of frequent lightning, the lightning arrester is installed to limit lightning overvoltage. But the lightning arrester can limit local overvoltage only. In fact, high-speed railway struck by lightning has affected the safety of power supply system in China. So more reasonable lightning protection measures for Chinas high-speed railway will be studied in this paper.
The Comparison Study of Four Lab Scale Microalgae Collection Ways
Authors: Du Ji Jun , Zeng Ping , Zhang Fan , Wang Chen Hao
Published: February 2014

Microalgae are a form of prospective biomass energy. Cultivation of wild mixed microalgae not only develop a new way for biomass energy production, but reduce the emission of carbon dioxide in flue gas, which is important to the alleviation of global climate change. The production of bio-flues using microalgae included microalgae cultivation, harvesting and product post-treatment. The cost-effective microalgae harvesting ways was beneficial for all the production process. This study was carried out on the basis of microalgae cultivation. The microalgae collection ways including centrifuge, filtration by slow filter paper, 13# and 25# plankton net were compared, the results showed that, the algae cell collection efficiency decreased as follows, centrifuge > filtration by slow filter paper >25# plankton net>13# plankton net. For the same collection way, the collection efficiency had a little difference according to different microalgae species. The most suitable collection way was centrifuge for the microalgae cultivation in lab.
600 MW Direct Air-Cooling Unit Back-Pressure Optimization and Theoretical Analysis
Authors: Zhao Hong Bin , Yan Yong Hui , Li Meng
Published: February 2014

In recent years, direct air cooling units have developed rapidly in China, but in the actual operation, the back-pressure often deviate from the optimal back-pressure, which affect the economy of the unit. The paper has figured out the optimum back-pressure, fan speed and power gain with the method of equivalent enthalpy drop; the paper also worked out the exergy loss of each device before and after the optimization. Through the exergy efficiency analysis of the devices before and after the optimization, we find out that after optimization, exergy loss of the turbine reduces by 0.954MW and the net amount of the generated power increases 130.5kW, the net exergy efficiency of units improves about 0.018 percent points.
Thermoeconomic Optimization of a 1000MW Coal-Fired Unit
Authors: Cheng Wei Liang , Ji Hui
Published: February 2014

In order to decrease the operation cost of a power plant, a 1000MW coal-fired power plant is studied as the research objective, and an evaluation model about unit thermoeconomic cost is built based on the thermoeconomic theory. By using the Matlab calculation tool, the thermoeconomic optimization of the energy system about the plant is presented. The results show that it is necessary to update the correlated equipment to increase its exergy efficiency in the design of the entry unit. Moreover, the exergy efficiency of the boiler is close to the optimum value, as for the steam turbine, its efficiency can be increased with the increment of investment.
Study on the Energy Consumption Distribution of 1000MW USC Unit
Authors: Duan Li Qiang , Li Ran , Yang Yong Ping
Published: February 2014

In recent years, the 1000MW ultra-supercritical unit has developed rapidly for its high efficiency and low energy consumption in china. In order to further reduce the energy consumption, the energy consumption distribution of a typical ultra-supercritical unit is analyzed in detail, which can make contribution for the energy conservation of units. Based on the theory of unit energy consumption and according to the thermodynamic calculation of a 1000MW ultra super critical generating unit under the design condition and off-design loads, this paper reveals the distribution of energy consumption rules of the whole unit, including every subsystem. The results indicate that when the load deviates from the design load, the total energy consumption of system will increase.
Thermodynamic Modeling of Allothermal Steam Gasification in a Downdraft Fixed-Bed Gasifier
Authors: Musinguzi Wilson B. , Okure Mackay A.E. , Sebbit Adam , Løvås Terese , da Silva Izael
Published: February 2014

A process of converting a solid carbonaceous fuel into a gaseous energy carrier in presence of a gasifying medium at high temperature is called gasification. The resulting gaseous energy carrier, known as producer gas, is more versatile in its use than the original solid fuel. Gasification is widely considered as a more efficient and less polluting initial thermochemical upstream process of converting biomass to electricity. The objective of this study was to investigate the process of allothermal steam gasification in a fixed-bed downdraft gasifier for improved quality (HHV, high hydrogen content) of the producer gas generated. The study involved thermodynamic equilibrium modeling based on equilibrium approach in which the concentrations of the gaseous components in the producer gas at equilibrium temperature are determined based on balancing the moles in the overall gasification equation. The results obtained suggest that the maximum equilibrium yield of producer gas with high energy density is attained at a gasification temperature of around 820°C and a steam/biomass ratio of 0.825 mol/mol. The equilibrium yield was richer in hydrogen at 52.23%vol, and with a higher heating value of 11.6 MJ/Nm3. Preliminary validation of the model results using experimental data from literature shows a close relationship. The study has further shown the advantage of using steam as a gasifying medium towards the improved quality of the producer gas generated.
Information Tracking System of Liquefied Petroleum Gas Industry in Taiwan
Authors: Tseng Yuen Hsien , Ho Zih Ping , Wu Sen Po
Published: February 2014

An information tracking system of the liquefied petroleum gas industry is important to the government in carbon emissions economics. This research applied an information tracking system to the liquefied petroleum gas industry. It also formulated finding a minimization unexpect LPG quantity (Gap), and auto plot the variation by time of a selected firm using html5 techniques, which unexpect LPG quantity (Gap) was over the predefined threshold. Through a web-structure dynamic tracking system, a manager can easily access the information of unexpect LPG quantity (Gap) firms. Future research suggests expanding this research to physical tank constraints calculation.
New Physical Effect Permits Factor-of-Ten Reduction in Energy Requirements for Cooling
Authors: Doubochinski Danil B. , Tennenbaum Jonathan
Published: February 2014

A revolutionary new technology for cooling and refrigeration, based on applications of nonlinear coupled oscillations to the atomization and evaporation of liquids, opens the way to order-of-magnitude reductions in the energy requirements for cooling and refrigeration in a wide range of applications. The basic principles of the new cooling method are presented, together with results of certified measurements carried out on laboratory prototypes of the new cooling process.
Study on Underlying Coal and Strata Pressure-Relief Principle and the Gas Extraction Technique under Upper Protective Layer Mining
Authors: Liu Jian , Zhao Jie , Gao Ming Song
Published: February 2014

By study on underlying coal and strata pressure-relief principle and the gas extraction technique under upper protective layer mining, we obtain the stress change and distribution law of underlying coal-rock mass. We analyze the deformation law and fracture development characteristics of underlying coal-rock mass movement. With mining proceeding ahead, the total floor coal and rock experiences compression deformation first, then expansion deformation and re-compaction of the continuous periodic destruction. Based on different development characteristics and status of underlying coal-rock mass, the underlying coal-rock mass under an effect of upper protective layer mining was divided into the floor heave fracture zone and the floor heave deformation zone in this paper. The permeability coefficient of change law of underlying the coal seam as follows: the original value-small decreasing-increasing greatly-reducing-stability at last. The field test for upper protective layer mining of Zhang-ji coal mine of Huainan shows that the effect of pressure relief of protected seam is very good. So it eliminates the risk of gas outburst, ensuring safety mining of the protected seam. The research has an important significance for safety and efficient production under similar exploitation conditions of low-permeability with high gas and outburst risk coal seam.
Controlled Release of Quercus infectoria Extract from Jackfruit Starch-Konjac Glucomannan Film
Authors: Satirapipathkul Chutimon , Jantarapun Katima
Published: February 2014

Jackfruit (JS)-konjac glucomannan (KGM) blend films were prepared using different concentrations of JS, KGM and glycerol. Their mechanical properties were determined. All the films exhibited significantly higher values of tensile strength and elongation at break than those of neat JS films. The values varied considerably depending on KGM and glycerol content. Quercus infectoria extract was embedded into the films and its release characteristics were controlled by changing the initial KGM content. This study suggests that the blend film has a potential use for advanced controlled release of bioactive extracts.
The Numerical Calculation of the Temperature Field of Water-Wall Tube of the Supercritical Boiler under Near-Critical Condition
Authors: Li Chun Yan
Published: February 2014

The spirally water wall are distributed on the plane and divided into seven sections. The mean heat flux of each section is determined using furnace thermal calculation in sections. The value of the pressure and temperature concerning the working medium at inlet and outlet of each tube are established by calculating enthalpy increasing. The vaporizing processes of the working medium in the spiral tube under the three working conditions: 70%BMCR, 65%BMCR and 60%BMCR are analyzed. The state of the working medium and the possibility of the heat transfer deterioration are estimated. More reliable references are provided for the appearance of the heat transfer deterioration.
Research on User-Side Distributed Power System Control Strategy
Authors: Pan Ming Ming , Tian Shi Ming
Published: February 2014

Distributed power system, especially the distributed power and micro-grid system in the mountain villages, islands and remote areas, has many advantages, which can be used as an effective supplement of grid to help solve the problem of electricity supply. The connected-grid inverter needs to be able to work in both grid mode and island operation mode in order to ensure the safety of the local critical load. The paper proposed the seamless switching control strategy for two modes of switching. The experimental results verify the property of the topology structure and control strategy.
Affection of Post-Nitrogen-Doping of ZnO Columnar Films Photo-Anode on Performance of Dye-Sensitized Solar Cells
Authors: Zhou Hong Quan , Zou Xiao Ping , Yang Gang Qiang , Teng Gong Qing , Huang Zong Bo , Zhang Bao Li
Published: February 2014

ZnO was a promising n-type conductive semiconductor material for dye-sensitized solar cells. Stable and efficient preparation of high quality p-type ZnO films became the main difficulty in current research. In this paper, a nitrogen-doped ZnO columnar film on an indium tin oxide (ITO) substrate was successfully obtained by gas phase method. The absorption of visible light was improved by nitrogen-doped ZnO columnar films. This experiment provided a good strategy for the full utilization of solar energy.
Influence of Humidity of Water-Oil and Water-Coal Dust Fuels on their Energetic, Economic and Ecological Combustion Benefits
Authors: Sajin Tudor , Buzdugă Ştefania Roxana , Olaru Dumitru , Anitei Florin
Published: February 2014

The economic, energetic and ecological indicators of combustion of water-oil emulsions and water-coal dust suspensions on a test installation are presented in this paper.
Design of the Temperature Field Test System of Power Electronic Packaging Modules
Authors: Hua Jun , Jin Peng Yun , Zheng Li Bing , Fang Hua Chao , Wang Chun Lei , Han Li , Song Ping
Published: February 2014

The defects of material, packaging process and layout in power electronic packaging modules can affect the temperature distribution. Defects such as the voids of the welding and the unreasonable layout will cause uneven distribution of the temperature field in the internal surface and the local hot spots will emerge. If the hot spots continued, the module will be damaged. In order to achieve the defect analysis based on the temperature field, a test system is designed. The infrared camera is used to measure the temperature distribution in the system. The system can test the temperature field distribution characteristics with different loads. The study provided a strong basis of defect analysis standards based on temperature field.
Research of Integrated Power Propulsion System Simulation Based on PSCAD
Authors: Lan Hai , Zhao Xin , Meng Jie
Published: February 2014

Modeling and simulation of generator, frequency converter, motor, propeller of integrated power system in PSCAD environment respectively, finally form a complete system, which contains the diesel engine and speed regulation system, generator and excitation system, motor and vector control system. Establish the propeller model as motor load by Fortran language. The motor load constantly changing, traditional PI controller parameters are not easily adjusted in real time, SNAPID controller based on the error changes in the changing, complete SNAPID controller in MATLAB environment and call MATLAB continually, the control effect of speed is improved in the process of marine propulsion. Finally simulate typical working condition of system, the simulation results show that propeller shaft torque is smaller when grading operating, the influence of electric propulsion system is smaller and conducive to maintaining the stability of the system.
Study on Variable Structure Vibration Control for Flexible Manipulator
Authors: Mu Hui Jin
Published: February 2014

In recent years, modeling and control of flexible space robots are extensively researched. Compared with traditional rigid robots, flexible robots have low energy consumption, wide operating space, high carrying capacity and other characteristics. However, due to its special structure, the robot arm will get deformation and vibration in motion, which brings a lot of problems to the positioning and tracking control of flexible space robots. Therefore, directing at the dynamics modeling and control issues of the free-floating flexible dual-arm space robots, this article carries out in-depth study. This paper first studies the elastic deformation and vibration of the flexible space manipulator and the robust control problem of the system trajectory tracking for free-floating flexible dual-arm space robots.
Human Machine Interface in Weld Seam Detection Using an RGB-D Camera
Authors: Silvers Glenn Alexander , Fang Gu
Published: February 2014

The set-up time in robotic welding needs to be reduced so that it can be used for limited production runs. One challenge in achieving this reduction is the automatic localisation of the weld seam. A method is developed in this paper to locate the weld seams by human-machine interface. In particular, this method uses an RGB-Depth sensor, such as the Microsoft XBOX Kinect sensor, to identify a human hand that is pointing at the weld seam. A ‘hybrid hand detector’ is developed to recognise the human hand and fingers using both the depth and colour information. In turn it enables the identification of the weld seam. Experimental results shown that the weld seam can be reliably identified using the proposed method at near real time speeds.