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## Über dieses Buch

The 3rd International Congress on Energy Efficiency and Energy Related Materials (ENEFM2015) was held from 19–23 October 2015. This congress focused on the latest developments of sustainable energy technologies, materials for sustainable energy applications and environmental and economic perspectives of energy. These proceedings included 40 peer-reviewed technical papers, submitted by leading academic and research institutions from over 23 countries and represented some of the most cutting-edge researches available. The sections included in the 40 papers are listed as follows:

Solar Energy, Fuel cells, Hydrogen productions, Hydrogen storage, Energy storage, Energy saving, Biofuels and Bioenergy, Wind Energy, Nuclear Energy, Fossil Energy, Hydropower, Carbon capture and storage, Materials for renewable energy storage and conversion, Photovoltaics and solar cells, Fuel generation from renewables (catalysis), Carbon dioxide sequestration and conversion, Materials for energy saving, Thermoelectrics, Energy saving in buildings, Bio-Assessment and Toxicology, Air pollution from mobile and stationary sources, Transport of Air Pollutants, Environment-Friendly Construction and Development, Energy Management Systems.

## Inhaltsverzeichnis

### Urban DC Microgrids for Advanced Local Energy Management with Smart Grid Communication

This paper presents an urban DC microgrid aiming an optimal energy management and taking into account messages from the smart grid. Concerning ancillary services, a microgrid controller is proposed to interact with the smart grid; it provides voltage control, power balancing, load shedding, and takes into account the system imposed constraints. Experimental results prove the technical feasibility of the urban DC microgrid. The study limits concern mainly the forecasting uncertainties and the real-time optimization.

Manuela Sechilariu

### Proper Orthogonal Decomposition Applied to a Turbine Stage with In-Situ Combustion

The paper presents a POD analysis of the numerical simulation results obtained from the numerical simulation of transport phenomena in a one-stage turbine-combustor (i.e. a turbine stage with in situ combustion). The motivation of this research is to investigate the new fuel injection concept that consists of a perforated pipe placed at mid-pitch in the stator row passage and different axial positions. The main goal of this simulation is to assess the stability of the in situ combustion with respect to the unsteadiness induced by the rotor-stator interaction. To identify the sources of instability for this complex flow, the proper orthogonal decomposition technique is used to analyze the natural patterns and couplings between various modes of pressure, temperature, velocity and chemical production rate distributions.

Dragos Isvoranu, Sterian Danaila, Paul Cizmas, Constantin Leventiu

### Strategies of Maximizing the Benefits of Storage and Diesel Generator for Standalone Microgrid

This paper proposed methods of maximizing the benefits of storage and diesel generator connected to a standalone microgrid. The analysis is based on the effects of site and size factors on the number of times diesel generator starts. Markov technique has been used for the analysis of the output powers of the WECS and SECS. The proposed method has been tested by increasing the rated power of the WECS and SECS by 25, 50, 75 and 100 %. The results have shown a decreased in the number of times a diesel generator starts by 2, 7, 9 and 9 % for WECS. Similarly, SECS decreased same by 4, 8, 11, and 13 %. Also, study of wind generator parameter at different cut-in-speeds levels, including 2, 2.5, 3.5 and 4 m/s reduced the number of times a diesel generator start by 122, 147, 116 and 134. In addition, the influences of storage and weather on the availability of system have also been investigated using Variable Boolean Logic Driven Markov process. In this case, the results have shown adding storage system; increased the microgrid availability by 0.058. In the same way, neglecting weather factor overestimate the system availability by 0.0104. Also, increasing the rated power of the WECS is the best way of maximizing the BCR of the system.

Abubakar Abdulkarim, Sobhy M. Abdelkader, D. John Morrow

### Optimal Control of the DC Motors with Feedforward Compensation of the Load Torque

The goal of the electrical drives is to control the mechanical load in accordance with the process requirements. The mechanical load is characterized by load torque and moment of inertia. Considering that the moment of inertia is reduced to the rotor of the electrical machine, optimal control of the DC motor with feedforward load torque compensation is proposed in this paper. In order to find the feedback component of the electrical drive system (EDS), Algebraic Riccati Equation (ARE) is solved. By adding a load torque dependent component to the DC armature voltage control, the mechanical load action is compensated. The compensator will lead to an increased voltage control such that the influence of the load torque will be eliminated. The numerical results of the EDS are shown. The method can be applied to electrical vehicles in order to compensate in real time the large variations of the load torque.

Marian Gaiceanu

### Photovoltaic Power Conversion System as a Reserve Power Source to a Modern Elevator

The main objective of this paper is to integrate a green source in the safety system of a modern elevator. In order to drive the elevator with 480 kg maximum load 1 kW induction motor is chosen. The sunlight through photovoltaic panels is converted into electricity. To ensure a continuous energy, an energy storage system is inserted in the power conversion system. The extracted energy is maximized by using the maximum power point tracking methods. A comparative analysis of these methods is presented. In order to size the necessary photovoltaic panels the potential of the local solar power is taken into account, i.e. the solar potential of Galati city, located in south-eastern region of Romania. In order to ensure a constant voltage the DC-DC power converter is inserted. The constant DC link voltage is used by the power inverter in order to supply the induction machine. The obtained numerical results confirm the feasibility of the solution.

Marian Gaiceanu, Cristian Nichita, Sorin Statescu

### Urban Cycle Simulator for Electric Vehicles Applications

The paper aims to accomplish a standardized simulator for urban cycle of an electric vehicle. The electric vehicle is supplied by two power sources: a fuel cell and a battery. Each source is connected in series with one three-phase inverter to a separate DC-DC converter in order to stabilize the voltage. Each of the two 3-phase inverters feeds alternatively the stator of an asynchronous machine with six phases. Field oriented vector control is involved; the obtained numerical results emphasize the quality of the strategy, and of the chosen architecture.

Marian Gaiceanu, Razvan Buhosu, Sorin Statescu

### Impacts of Network Structure on the Optimum Design of Hybrid Standalone Microgrid

In this paper a new methodology is proposed to investigate the impacts of network structure on the optimum design of microgrids. The proposed microgrid consists of PV, wind, battery storage and diesel generator. By introducing some approximations the relationships between wind turbine and PV module were expressed as linear functions of wind speed and solar radiation respectively. Therefore, the problem is formulated as a linear optimization problem that minimized the annual cost of the system. A computer program is developed in Matlab to formulate the optimization problem. Output of the optimization procedure show the viability of the proposed method by reducing the carbon emission by 70.40 % compared to operating the system on diesel generator alone. The result also shows that DC and AC coupled microgrid could reduce the system annual cost of hybrid microgrid by 5 and 2.8 % respectively. In addition, the effects of diesel prices, battery storage parameter, storage technology on the optimum system configurations have been investigated.

Sobhy M. Abdelkader, Abubakar Abdulkarim, D. John Morrow

### Energy Yield Potential Estimation Using Marine Current Turbine Simulations for the Bosphorus

In this work, several simulations and analyses are carried out to investigate the feasibility of generating electricity from sea underwater currents at Istanbul Bosphorus Strait. Bosphorus is a natural canal which forms a border between Europe and Asia by connecting Black Sea and Marmara Sea. The differences in elevation and salinity ratios between these two seas cause strong underwater currents. Depending on the morphology of the canal the speed of the flow varies and at some specific locations the energy intensity reaches to sufficient levels where electricity generation by marine current turbines becomes economically feasible. In this study, several simulations are performed for a 10 MW marine turbine farm/cluster whose location is selected by taking into account several factors such as the canal morphology, current speed and passage of vessels. 360 different simulations are performed for 15 different virtual sea states (for 5 significant wave heights and 3 peak periods). Similarly, 8 different configurations are analyzed in order to find the optimum spacing between the turbines. Considering that the complicated morphology of the strait may cause some spatial variations in the current speed within the selected region, the analyses are performed for three different flow speeds corresponding to 10 % increase and decrease in the average value. For each simulation the annual energy yield and cluster efficiency are calculated.

Hasan Yazicioglu, K. M. Murat Tunc, Muammer Ozbek, Tolga Kara

### Co-pyrolysis of Lignite-Oil Shale Mixtures

In this study, conversion of lignite has low calorific value with oil shale have been co-pyrolysed to investigate as an energy source and chemical feedstock. Pyrolysis of Balıkesir Dursunbey lignite (Turkey), Seyitömer oil shale (Turkey), and co-pyrolysis of their mixtures were carried out in a fixed bed reactor at different temperatures and mixture ratios. Pyrolysis experiments were performed in the temperature range of 400–700 °C with mixtures consisting of lignite/oil shale at a weight ratio of 33 % (w/w), 50 % (w/w) and 67 % (w/w). The effect of temperature and different ratios of lignite/oil shale in mixtures on product distribution and fuel properties were investigated. Tars obtained by different experimental conditions were characterized using spectroscopic and chromatographic techniques such as GC-MS and FTIR and the effect of experimental conditions on the formation of this valuable product was determined. The highest tar yield was obtained at 600 °C with a 67 % weight ratio of lignite to oil shale.

Uğur Hayta, Pınar Acar Bozkurt, Muammer Canel

### Airborne Wind Energy—A Review

Airborne Wind Energy (AWE) is a new approach to harvest stronger wind streams at higher altitudes for renewable energy. This paper reviews recent developments in this field. Conventional wind energy and current constrains for its development are discussed and airborne wind energy as an appropriate solution in the literature is reviewed. Different AWE technologies are reviewed and appraised and other related issues such as transmission and curtailment are discussed.

Mahdi Ebrahimi Salari, Joseph Coleman, Daniel Toal

### Full Utilization Control of Stored Energy in Lithium-Ion Batteries Based on Forecasted PV Output for HEMS

Renewable energy resources such as photovoltaic (PV) are crucial to counter an incoming energy crisis in the future. Nevertheless, when PV generators are integrated with storage batteries, a constructive mechanism needs to be structured in order to securely control the energy flow in the batteries during the charging/discharging process so that the risk of over-charge/over-discharge of the batteries can be prevented. Furthermore, it is extremely essential to implement a control method that is capable to fully utilize a stored energy in the scope of small-scale BESS to the load regularly in the first place before it is further scaled up to a mega-structure. In this study, an energy control scheme that considers and executes a next-day forecast of generation based on Grid Point Value as an input data has been proposed. Experimental equipment was structured and the system’s operation was completely administered by an RX621 microcontroller. Good experimental results were obtained corresponding to the trend of simulation results.

Ahmad Syahiman Mohd Shah, Yuki Ishikawa, Hiroki Takahashi, Suguru Odakura, Naoto Kakimoto

### Optimization of Hydropower Plants’ Tailwater Energy: A Case Study for 317 MW Adana Sanibey Dam, Turkey

This work is concerned with the optimization of use of tailwater energy at hydropower plants. As a case study, extensive analyses are performed to determine the main features of the array of low-head turbines that are planned to be installed at the tailwater of the two main generators of Sanibey Dam. Sanibey Hydropower Plant is constructed on Seyhan River at Aladag region, Adana, Turkey. The plant has currently two Francis turbines (158.5 MW of each) with a total capacity of 317 MW. Tailwater can be briefly defined as the water leaving the main generators of the hydropower plant. Although most of its energy is converted to mechanical energy by rotating the blades of the turbine, it has still some energy which can be exploited by using low head run-of-river type turbines. Design and optimization of these secondary systems are nowadays among the popular research topics. This work investigates the feasibility of developing such a hydro-matrix structure consisting of an array of low-head small size turbines. Several analyses are performed to determine the optimum number and technical specifications of the generators. In this work, two different approaches aiming at maximizing the power output or minimizing the investment return period are utilized in the optimizations. Two year outflow statistics and hourly data of several operational parameters of the existing Francis turbines (provided by the operators of the dam) are analyzed to maximize the power output. Similarly, energy markets hourly price data is used for calculating the corresponding payback period and to minimize the return time of the investment. The results of the analyses obtained by using different design objectives are quite similar. The approach aiming at minimizing the payback period yields the optimal number of turbines as 27. The return time and the cost of the investment are 8.13 years and 4,940,310 USD, respectively. In power maximizing approach, the optimum number of turbines is calculated as 30. The return time and the cost of the investment are 8.15 years and 5,490,978 USD, respectively. The re-use of expensive raw material (water in this case) also results in approximately 6 % increase in the overall efficiency of the hydropower plant.

K. M. Murat Tunc, Sedat Sisbot, Muammer Ozbek

### Adsorption Study of Reactive Blue 2 Dye on CTAB-Bentonite in Aqueous Solution

Cetyltrimethylammoniumbromide-bentonite (CTAB-bentonite) was synthesized by placing alkylammonium onto B-Na+, and investigated for adsorption of reactive Blue 2 dye from aqueous solution. The adsorption capacity of reactive blue 2 onto organo-bentonite was found to increase with the dye concentration. The evaluated activation energy was found as 8.02 kJ/mol. Equilibrium adsorption isotherms were satisfactorily described by Langmuir model.

Kheira Chinoune, Zohra Bouberka, Nesrine Touaa, Ulrich Maschke

### Deactivation of Polybrominated Flame Retardants by Ultraviolet Radiation

The European directive RoHS (Restriction of the use of certain Hazardous Substances) limits the use of specific toxic substances for example a number of flame retardants. In the light of this context, this work handles with the implementation of a methodology of deactivation by radiative exposure of Tetrabromobisphenol A bis-(2,3-dibromopropylether) (TBBPA-DBPE), concerned by the RoHS directive. It has been shown that the photodegradation by UV-visible irradiation of TBBPA-DBPE in Tetrahydrofuran as organic environment generates less brominated thus less toxic congeners. Physico-chemical analyses were realized by means of a spectroscopic technique that allows to characterize products before and after irradiation under UV-visible light.

Kahina Bentaleb, Zohra Bouberka, Abdelouahab Nadim, Ulrich Maschke, Yassine Agguine, Said Eddarir

### Bandwidth Improvement of Patch Antenna Printed on Anisotropic Substrate with Modified Ground Plane

Today, the state of the art antenna technology allows the use of different types and models of antennas, depending on the area of application considered. The antenna must be small enough for miniaturizing the wireless communication system, which have been extensively and rapidly used in the modern word, also the future communication terminal antennas must meet the requirements of multiband or wideband, the difficulty of antenna design increases when the number of operating frequency bands increases. Microstrip patch antennas are now extensively used in various communication systems due to their compactness, economical efficiency, light weight, low profile and conformability to any structure. This paper is focused on the multiband application of the microstrip patch antenna, the effects of different physical parameters on the characteristics of the structure are investigated, the results in terms of return loss, bandwidth and radiation pattern are given, the proposed structure can be scaled to meet different frequencies of wireless communication systems just by changing the dimension of the main antenna. An inset L-shaped feed rectangular patch antenna with dual rectangular slots etched on the ground plane is proposed and analyzed for increasing bandwidth of microstrip patch antenna. The results in terms of return loss, bandwidth and radiation pattern are given. The results show that dual wide bands are achieved and a better impedance matching for the upper and lower resonances are obtained. Simulation results for the effect of uniaxial anisotropic substrate on the return loss and bandwidth of the rectangular patch antenna using inset L-shaped feed with dual rectangular slots on the ground plane are also presented. This novel wideband proposed antenna provides a significant size reduction and can improve the bandwidth. Furthermore, comparative studies between our results and those available in the literature is done and showed to be in good agreement.

Amel Boufrioua

### An Expert Committee Evaluation for Load Forecasting in a Smart Grid Environment

Electricity markets as well as integration of renewables and electric vehicles impose new requirements for efficient energy management, turning load forecasts into an essential tool for safe system operation at the lowest cost. However, the diverse load dynamics identified in a distribution system necessitate the development of novel forecasting models capable of accurate load forecast provision in a smart grid environment. The load forecasting system under evaluation is an expert committee which comprises four prediction models (PMs) and one combination model (CM) and provides forecasts in a 24-h ahead forecasting horizon. The load forecasting system performance is validated using data from four actual load time series characterized by large diversity. The expert committee exhibits satisfactory performance on all load profile tested, effectively capturing the load dynamics.

Th. Boutsika, G. Sideratos, A. Ikonomopoulos

### Linking Smart Energy and Smart Irrigation: Integration, System Architecture, Prototype Implementation and Experimentation

Irrigation is, for certain geographical regions, a vital activity which often happens to be an expensive one. For those regions, irrigation commonly accounts to significant energy consumption. In this paper, we propose to investigate the possibility of reducing the cost of irrigation by utilizing techniques, methods and practices that are common in the next generation energy systems, known also as smart energy systems. Specifically, we design, implement and evaluate a software platform that couples the smartness of the irrigation systems with the smartness of the energy systems. The resulting simulation engine allows large scale and very detailed experimentation which allow irrigation experts to specify energy effective configurations that lead to the reduction of the irrigation cost through smart utilization of Renewable Energy Sources.

Elias Houstis, Antonia Nasiakou, Manolis Vavalis, Dimitris Zimeris

### Some Issues of Industrial Scale Silicon Isotopes Separation by the Laser Assisted Retarded Condensation Method (SILARC)

Advancing miniaturization of microelectronic devices makes the heat removal problem extremely important. It makes to search for cheaper ways for silicon isotopes production. We discuss a number of important constraints to be considered for optimal design of industrial scale silicon isotopes separation facility relying on the laser assisted retarded condensation method. Our calculations are based on the transport model for overcooled, rarefied, and supersonic gas flow in the laser field with frequency tuned for excitation of specific isotopomer.

K. A. Lyakhov, H. J. Lee

### Inkjet Printing and Inkjet Infiltration of Functional Coatings for SOFCs Fabrication

The feasibility of the inkjet printing technique in the fabrication and modification of electrodes and electrolytes for Solid Oxide Fuel Cells (SOFCs) was studied. A variety of suspension (NiO, YSZ, Gd-doped ceria, LSM) and solution inks (Co nitrate) were optimised for inkjet printing of functional coatings and infiltration of electrodes’ backbone structures. The printing parameters were studied in order to optimize the inks jetting and the uniformity of the inks delivery which allowed for precise thickness and infiltration depths control. Maximum power density of ~0.220 W cm−2 was measured in H2 at 800 °C on Ni-8YSZ/YSZ/LSM single cell 50 × 50 mm in size. Inkjet printed symmetrical LSM cathodes cells were inkjet infiltrated with Co nitrate inks and characterized by impedance spectroscopy in order to study the relation between the nano-decoration of the cathode scaffold and its electrochemical performance.

R. I. Tomov, M. Krauz, Chenlong Gao, S. Hopkins, R. V. Kumar, B. A. Glowacki

### Modelling of the Bending Behaviour of a Double-Reinforced Beam from Recycled Materials for Application in NZEBs

A number of design approaches of nearly zero energy buildings (NZEBs) are known in literature. The aim of the present paper is to study the bending behavior of a structural bi-material element of a recycled concrete beam reinforced along its lower and upper side by highly-tough thin layers. On one hand, the design of such a structural element would produce a light weight element, since no conventional reinforcement would be involved, and on the other hand, the recycled aggregate of the concrete matrix would make the element applicable to NZEBs. Thus, natural energy resources may be saved. Moreover, thin reinforcing layers guarantee good bearing capacity due to their high toughness, excellent crack resistance under dynamic impacts, as well as fire resistance when fabricated from special polymer materials. The approach of employing such lightweight structural bi-material elements in constructions is energy saving and innovative. The study provides a method of specifying the thickness of the reinforcing layer assuming the existence of a transition area between the two materials and smooth transition between the reinforcing layer and the concrete bulk. It is also assumed that the element operates within the materials linear-elastic zone, without generation of macrocracks within concrete and debonding along the interface. The analytical results found are verified by subsequent experimental evidence available in literature.

Anguel Baltov, Ana Yanakieva, Gergana Nikolova

### Tuning of Dielectric Parameters of (CNTS)X/Cutl-1223 Nanotubes-Superconductor Composites

Carbon nanotubes (CNTs) and (CuTl)0.5Ba2Ca2Cu3O10-δ (CuTl-1223) superconducting phase were mixed in appropriate ratios to obtain (CNTs)x/CuTl-1223 (0 ≤ x ≤ 2.00 wt%) nanotubes-superconductor composites. Crystal structure and chemistry of CuTl-1223 phase were not affected significantly but superconducting properties were suppressed after inclusion of CNTs. The decrease in dielectric parameters can be attributed to reduction of polarization due to semiconducting nature of CNTs in these composites. Positive space charges around the electrodes may be the possible cause of negative capacitance (NC) in these composites. The dielectric parameters of these composites can be tuned by the frequency, operating temperature and CNTs content in these composites.

M. Mumtaz, Zahir Usman

### Modeling of a Heat Pipe for Using in Thermoelectric Energy Harvesting Systems

Thermoelectric energy harvesting systems (EHS) consist of thermoelectric generators (TEG), which generate electrical power due to a temperature difference. Consequently, a main challenge to build up such an EHS is a good heat transfer to and from the TEG. On the one hand heat has to be send to the hot TEG side and on the other hand the waste heat from the cold TEG side has to be dissipated. For this heat transfer heat pipes are very reasonable. They have a 1000-fold better thermal conductivity than copper and so the existing heat quantity can be used more effectively. To model a heat pipe in a most general way, the modeling language Modelica® is used. Thereby, the model can be build based on its physics as well as its material properties. The dimensions of the pipe as well as the used working fluid or the used heat pipe material are parameters adjustable for specific cases. In this contribution, the theoretical aspects of a heat pipe will be described and the modeling with Modelica® for different modeling approaches in the simulation environment Dymola® will be shown. Finally, the model of the heat pipe will be validated with laboratory measurements.

Marco Nesarajah, Georg Frey

### Electron Thermostating Elements for Controlling Consumption of Heat Transfer Agent in the Heating Systems

Electron thermostating elements (ETE) mounted on the regulating radiator valves are developed. ETE are designed for the automatic controlling of the consumption of heat transfer agent in the heating systems by a special program. So, ETE are intended for the controlling of the temperature in the heated placements. ETE have autonomous power supply. Optimization of the working algorithm of ETE in conjunction with the high efficiency of the servomotor, and low level of power consumption of the electronic circuit allowed authors to increase the time of autonomous work of ETE. Proposed design solutions of ETE can be used also in different fields of science and technology for the automatic controlling of the consumption of liquid and gaseous agents.

Yury I. Shtern, Ya S. Kozhevnikov, I. S. Karavaev, V. M. Rykov, M. Yu Shtern

### Investigation and Calibration Methods of Precise Temperature Sensors for Controlling Heat Consumption

Authors developed precise temperature sensor with wireless interface (WTS). Methods of thermocompensation and individual calibration of WTS were developed in order to provide high requirements of the temperature measurement accuracy (0.02 °C). Measuring hardware-software complexes for the realization of this methods and carrying investigations were also developed.

Yury I. Shtern, Ya. S. Kozhevnikov, I. S. Karavaev, M. Yu. Shtern, A. A. Sherchenkov, Maxim S. Rogachev

### Thermoelectric Generators: A Review of Present and Future Applications

In the last centuries, men have mainly looked into increasing their production of energy in order to develop their industry, their means of transport and their quality of life. Since the recent energy crisis, researchers and industrials have mainly been looking into managing energy in a better way, especially by increasing the efficiency of energy systems. This context explains the growing interest for thermoelectric generators (TEG). Today, TEGs allow us to collect lost thermal energies, to produce energy in extreme environment, to produce electric power generation in remote areas and to produce micro production for sensors. Direct solar thermal energy can also be used to produce electricity. This review begins with the basic principles of thermoelectricity and with a presentation of existing and future materials. The design and optimisation of generators are tackled. Many recent applications are presented as well as the future applications which are being studied in laboratories or in industry.

Daniel Champier

### Electron-Spin Resonance of Type II Si-Clathrate Thin Film for New Solar Cell Material

Silicon clathrate thin films, Na x Si136 (x > 5), were prepared on Si (111) substrates. The X-ray diffraction (XRD) pattern shows a mixture of the type II Si-clathrate crystalline and amorphous phases. The electron-spin resonance (ESR) spectrum for the Si-clathrate thin film consists of two lines with a set of $$g$$g value and width, ($$g$$g, $$\upgamma$$γ(mT)) = (2.005, 1) and (2.002, 0.1). In comparison, the ESR spectra for Na x Si136 (x = 5.5, 11) polycrystalline powders have a fairly broad line with ($$g$$g, $$\upgamma$$γ(mT)) = (~2.05, 15) other than the above two lines. Such broad line may be assigned to a Na-Na pair and/or a Na-cluster in the Si-clathrate polycrystalline powders. These ESR results suggest that the dominant line with ($$g$$g, $$\upgamma$$γ(mT)) = (2.005, 1) observed for the Si-clathrate thin film is assigned to electron trapped at a Si-deficit with a dangling bond created in the amorphous phase.

Mitsuo Yamaga, Takumi Kishita, Tetsuji Kume, Koki Uehara, Masaki Nomura, Fumitaka Ohashi, Takayuki Ban, Shuichi Nonomura

### The Power Supply of the Hydrogen Generator

In the paper the circuit supplying the hydrogen generator is considered. The idea of operation of this circuit, its simulation schema and the results of computations are presented. These computations were performed for a wide range of frequency of the supplying current. The correctness of the idea of operation of the supplying circuit is shown and the dependence of efficiency of the hydrogen generator on frequency of the supplying current is presented.

Krzysztof Górecki, Janusz Zarębski, Paweł Górecki, Sławomir Halbryt

### The Use of Photo-Voltaic Panels to Charge Mobile Electronic Devices

In the paper the circuit to charge mobile electronic devices and the results of measurements of this circuit are presented. The construction of the presented circuit is analysed and the influence of the selection of the photovoltaic panel and optical power density on its surface on current efficiency of the considered circuit are discussed. The directions of the development of the worked out and constructed circuit are pointed.

Paweł Górecki, Krzysztof Górecki, Ewa Krac, Janusz Zarębski

### Optimized Rapid Thermal Process for Selective Emitter Solar Cells

In this paper we present an experimental approach for the realization of selective emitter by laser doping. Multi-crystalline Silicon wafers with thin layer of silicon nitride (SiNx) are treated by laser after phosphorous diffusion and PSG removal. Rapid thermal annealing temperatures from 700 to 900 °C have been used for screen printed contacts. The surface of the selective emitter before and after annealing has been observed by scanning electron microscopy (SEM). Electrical characteristics show performance amelioration of the cell efficiency.

### Integrating Superficially Treated 2024 Aluminum Alloy in Steel Drill String to Deal with Fatigue Problem in Crooked Trajectory for Vertical Deep Well

Drilling deep HPHT wells is the most compelling reason for drilling companies to look for alternative drill pipes that meet their requirements. Currently, with the emergence of drill pipes made of materials other than steel, a thorough study of superficially treated 2024 aluminum alloy combined with steel drill pipe in crooked well trajectory is presented in this study. Basically; this study is built on several parameters that affect fatigue resistance of a drill pipe such as fatigue endurance limit of the drill pipe material, drill pipe specification, torque and drag loads applied, dog leg severity, besides crooked trajectory. Chiefly, this paper shows a full study about 2024 aluminum alloy drill pipe and analyzes the prospect of using aluminum drill string for deep wells while the fatigue, torque and drag as well as drilling efficiency and drill string integrity stay acceptable. It also gives a better comprehension of the mechanical behavior of lightweight material for drill pipe, which can significantly improve well planning in order to drill wells with an increasing depth, length and complexity. Additionally, even though steel drill pipe has better mechanical properties in terms of density, Young’s modulus, yield and tensile strength, than 2024 aluminum alloy drill pipe, the latter has a good fatigue resistance even in the simultaneous presence of high applied torque and axial load, and severe doglegs, which makes the use of other options (Steel Drill Pipe and Titanium Drill Pipe) impractical from the fatigue failure standpoint. Finally we can assume that, there is significant cost saving with the use of Aluminum Drill Pipe compared to steel drill pipes, because the ratio of the engine power needed to supply the drilling fluid at the required pressure for ADP versus steel drill pipe is lower, leading to a reduction in fuel consumption.

Lallia Belkacem, Noureddine Abdelbaki, Mohamed Gaceb, Elahmoun Bouali, Hedjaj Ahmed, Mourad Bettayeb

### Performance of Bi2Te3 Thermoelectric Element Improved by Means of Contact System Ni/Ta-W-N/Ni

In this paper the materials with improved thermoelectric properties developed based on Bi2Te3 were used for the production of thermoelectric generator. It allowed to extend the operating temperature range of the material to 550 K. Bi2.0Te2.4Se0.6 doped with 0.12 wt% CuBr (dimensionless coefficient ZT = 1.1 at a temperature of 450–550 K) was used as a material for manufacturing n-type branches. Bi0.4Sb1.6Te3.0 doped with 0.12 wt% PbCl2 and 1.5 wt% Te (dimensionless coefficient ZT = 1.2 at a temperature of 450–550 K) was used as a material for manufacturing p-type branches. The following materials were used as the contact system: 100 nm layer of nickel as the ohmic contact layer; 100 nm layer of amorphous alloy Ta-W-N as a diffusion barrier layer; and 400 nm layer of nickel as a wetting layer for soldering. Study of adhesion of this contact system demonstrated good quality. The breakout force was 12 MPa.

Dmitry G. Gromov, Yury I. Shtern, Maxim S. Rogachev, Alexey S. Shulyat’ev, Alexey Yu. Trifonov, Elena P. Kirilenko

### Investigation of the Crystallization Kinetics in the Phase Change Memory Materials of Ge–Sb–Te System

In this work mechanism and kinetics of crystallization for thin films on the basis of Ge–Sb–Te–Bi and Ge–Sb–Te–In perspective for phase change memory application were investigated. Possible data processing and storage times of the PCM cell were estimated. It was shown that PCM cell based on Ge2Sb2Te5 + 0.5 wt% Bi have minimum data processing and maximum data storage times in comparison with the other investigated materials.

A. Sherchenkov, S. Kozyukhin, A. Babich, P. Lazarenko, S. Timoshenkov, A. Shuliatyev, A. Baranchikov

### Fuel Cell for Standalone Application Using FPGA Based Controller

Currently, escalation in consumption of energy, instability of crude oil price and global environment change has forced researchers to focus more on renewable energy sources. There are different new and renewable energy sources (such as photovoltaic and wind energy), however each possess some limitations or other. Fuel Cell is an important alternative that can be compared to other new and renewable sources of energy and proved to be better in certain terms and Solid oxide fuel cell (SOFC) is a more efficient, environmental friendly renewable energy source. This paper focuses on load/grid connected fuel cell power system (FCPS) which can be used as a backup power source for household and commercial units. This backup power source would be efficient and will provide clean energy at an affordable per unit cost. Load/grid connected fuel cell power system mainly comprises a fuel cell module, DC-DC converter and DC-AC inverter. This work primarily focuses on solid oxide fuel cell (SOFC) modelling, digital control of DC-DC converter and DC-AC inverter. Extensive simulation is conducted to validate our concepts and some experimental results confirm the same. Dynamic mathematical model of SOFC is developed to find out output voltage, efficiency, and losses in fuel cell stack. One output from fuel cell is DC voltage that is fed to a DC-DC converter for stepping up as usually this is a low voltage. Proportional-Integral (PI) controller and FPGA based PI controller are implemented and experimentally validated. The prototype of single phase system having fuel cell as input and delivering ac power is developed. FPGA (Field Programmable Gate Array) implementation of HCC is done using NI-cRIO-9014. FPGA implementation of three phase model of fuel cell power system is developed using adaptive-fuzzy-HCC using Xilinx/System Generator.

Kamalakanta Mahapatra, Kanhu Charan Bhuyan

### Al2O3 + TiO2 Thin Film Deposited by Electrostatic Spray Deposition

In the paper are presented the morphology of Al2O3 + TiO2 thin film produced by electrostatic spray deposition method and the results of investigations of its endurance when subjected to thermal cycles and slurry erosion. The film was produced in steam atmosphere by simultaneously spraying of colloidal suspension of Al2O3 nanoparticles in propanol-2 (as a solvent) with the addition of C10H20O5Si (to improve film adhesion) and 1 % solution of butoxy titanium Ti(OCH2CH2CH2CH3)4 in propanol-2 as a precursor of TiO2. Performed investigations showed that Al2O3 particles and TiO2 particles are uniformly distributed within the film, and that the weight content of aluminum and titanium is nearly the same. The thermal tests did not cause any fracture of the film but decreased film adhesion. Decreased adhesion of the film intensified degradation during slurry test.

Alicja K. Krella, Andrzej Krupa, Arkadiusz T. Sobczyk, Anatol Jaworek

### Mechanism of Breakdown and Plasma Evolution in Water Induced by Wide Pulse Widths of Laser Radiation: Numerical Study

Numerical simulation‏ is presented to investigate the experimental results that carried out to study the breakdown of distilled water as a good emulate of the ocular tissue of the eye. The experiment used a visible laser source (580 nm) operating with pulses of width 100 fs, 30 ps, and 6.0 ns. The model solves numerically a rate equation that describes the temporal evolution of the electron density in the focal volume under the collective effect of multi-photon and‏ electron collision‏ ionization processes. Besides diffusion of electrons from the interaction region and recombination are considered as removal mechanisms. The model is validated by carrying out the calculations to obtain first a comparison between the threshold intensity as a function of the pulse width and the experimentally measured ones. Secondly, a detailed investigation of the physical processes which contribute to water breakdown connected with each laser pulse width is performed. This study is fulfilled by the determination of; the temporal evolution of the electron density at the center of the focal volume and along its radial and axial distances. The results also presented the localized distribution of the electron density in the formed plasma and its surrounded ionization regions. Finally, the effect of laser power on the linearity of the medium at the interaction region is examined for the three laser pulses to clarify the role of the self-focusing phenomenon.

Kholoud A Hamam, Yosr E. E. D. Gamal

### Research Towards Energy-Efficient Substation Connectors

The contact resistance is the main variable that defines the energy efficiency of an electrical connection, its stable performance and long term service. It is worth noting that according to the measurements performed in this work, the contact resistance in substation connectors can be several times that of the connector’s resistance. To reduce connection losses and thus increase connector’s efficiency, it is important to minimize contact resistance, to ensure an efficient connection. The aim of this work is to find out, by means of experimental measurements, the relationship between the different components of contact resistance in substation connectors and the main related variables such as material properties, applied bolts torque, true contact area, or surface’s conditions among others. Furthermore, this study proposes a novel surface treatment for substation connectors, which allows reducing the contact resistance. Experimental measurements demonstrate the effectiveness of the novel chemical treatment in improving energy efficiency in substation connectors.

F. Capelli, J.-R. Riba, A. Rodriguez, S. Lalaouna
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### Systemische Notwendigkeit zur Weiterentwicklung von Hybridnetzen

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