International Journal of Energy and Environment

ISSN: 2308-1007
Volume 11, 2017

Notice: As of 2014 and for the forthcoming years, the publication frequency/periodicity of NAUN Journals is adapted to the 'continuously updated' model. What this means is that instead of being separated into issues, new papers will be added on a continuous basis, allowing a more regular flow and shorter publication times. The papers will appear in reverse order, therefore the most recent one will be on top.

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Volume 11, 2017

Title of the Paper: Adaptive Current -Voltage Control Scheme for Variable Pulse Load in a Hybrid DC Micro Grid by PV-MPPT Burp Charging Technique


Authors: M. Pala Prasad Reddy, T.Pavan Kumar, C. Shekshavali

Pages: 101-106

Abstract: In this paper, the proposed controlled technique is PV-MPPT burp charging technique. By applying charging technique Vdc ripples are minimized. Better voltage regulation at load side even in presence of pulsed loads Battery life improvement with tickle charging-more reliable. The another technique is an adaptive current-voltage control (ACVC) scheme based on the moving average measurement technique and an adaptive proportional compensator. This technique can be controlling both voltage and current of the system while keeping the output current of the power converter at a relatively constant value. ACVC technique can be improves the dynamic performance of the hybrid dc microgrid. Although the ACVC technique causes slightly increases the bus voltage variation, it effectively eliminates the high current and power pulsation of the power converters. Using the experimental results comparing between ACVC and Burp charging technique. ACVC technique increases the grid efficiency and reduces the voltage drops in the system.

Title of the Paper: Analysis of a Doubly Fed Induction Generator through Experimental Verification


Authors: Milkias Berhanu Tuka, Roberto Leidhold, Mengesha Mamo

Pages: 94-100

Abstract: Experimentation is very important, mainly for the determination of machine parameters like stator and rotor resistances, leakage, self and mutual inductances of the Doubly-Fed Induction Generator (DFIG) which are used in modelling and simulations. These parameters are sometimes difficult to get directly from the nameplate as they are manufacturer (company) secrets in most cases. The parameters of a machine can say a lot about its overall performance behaviors. In addition, experimentation can support and prove simulation results. Thus, the work carried out on a 1kW DFIG in this study analysis its performance under various conditions. The given machine has five rotor positions. Hence the impacts of the rotor at these five positions have been investigated. With the aid of simulation and experimental results, variations of torque, stator current and power, efficiency, and power factor have been investigated with regard to the mechanical output of the machine. The simulation & experimentation encompasses the machine side converter (MSC) for controlling. Comparisons of simulation and experimental results have been done and confirm the validity of analysis with some small deviations.

Title of the Paper: Spatial Distributions of Surface-Air-Temperature on the Tibetan Plateau and its Recent Changes


Authors: Mingyuan Du, Jingshi Liu, Xianzhou Zhang, Yingnian Li, Yanhong Tang

Pages: 88-93

Abstract: It is important to know the spatial distributions of each climate element to evaluate local climate characteristics and long-term climate change on the Tibetan Plateau (TP) because of its huge area (about 2.5 × 106 km2) and its complex terrain. We analyzed the monthly mean surface air temperature data of 90 meteorological stations from China Meteorological Administration on the TP. A linear model is used to examine the effects of altitude, latitude, longitude and other local environmental factors (valley, slope orientation, urban and other land use etc.) on the surface air temperature focusing on two periods: 1956-1980 and 1981-2005. The linear model shows that surface air temperature decreases with increase of altitude, latitude and longitude. The model reveals that the lapse rate increased from 0.579ºC/100m for 1956-1980 to 0.594ºC/100m for 1981-2005. This means that recent warming; especially warming in wintertime (when the lapse rate changed from 0.581ºC/100m to 0.617ºC/100m) is clearer at lower altitude than at higher altitude. The study also shows that the latitude variation rate becomes smaller and longitude rate becomes greater in recent years,suggesting that the distribution of surface air temperature becomes less parallel to latitude and more parallel to longitude and that recent warming seems clearer in northwest part than in southeast part of the TP. The local environmental changes such as urbanization and land cove change may play very important role for the geographical changes of recent climate warming.

Title of the Paper: Development of Multi-Objective Operation Rule Curve for Hydropower Reservoir System Using Reservoir System Simulation and Constraint Optimization GA-KS, Case Study: Hydropower Reservoir System in Ca River Basin


Authors: Le Xuan Cau

Pages: 81-87

Abstract: Objective of the present research is the development of optimal daily rule curve for multi-purpose hydropower reservoir system. A daily rule curve consists of upper rule curve and lower rule curve. At a given time of year and current reservoir water level, an operator determines outflow discharge from reservoir by using rule curve. Multi-purpose hydropower reservoir system needs the daily rule curve to support operating effectively in both short term and long term. The rule curve is a useful tool to support the daily operation of hydropower reservoir system. The rule curve for multi-purpose hydropower reservoir system constructed for daily reservoir operation to achieve the objectives such as: the largest total electricity production, minimal spill water, the smallest shortage of water supply water level of reservoir at the end of the flood season, a higher water level at the end of the dry season than the dead water level. The article presents a method of optimal rule curve construction for hydropower reservoirs. The optimal rule curve for the hydropower system is determined by setting the objective function for reservoir operation and construction of reservoir operation rule curve by using hydropower reservoir system simulation, global optimization method (Genetic Algorithm), constraint optimization method (Kreisselmeier-Steinhauser function KS). Optimal daily rule curves have been built based on monthly rule curves. The optimal daily rule curves is determined through upper rule curve coefficient αupper (0≤αupper ≤1) and lower rule curve coefficient αlower (0≤ αlower ≤1) given monthly rule curves. The advantages of optimal daily rule curves are proved by comparing operating results according to existing monthly rule curves and to optimal daily rule curves based on calibration data sets and validation data. A program for development of optimal daily rule curve for multi-purpose hydropower reservoir system is built. The program consists of hydropower reservoir system routing module, hydropower reservoir system operation module, and global constraint optimization module. There are three hydropower reservoirs on Ca River, Vietnam (The BanVe reservoir, KheBo reservoir, BanMong reservoir). Applying the program, the research has developed an optimal daily rule curve for multi-purpose hydropower reservoir system on Ca River by using daily inflow data in 41-year period. Operating according to the obtained daily rule curve for multi-purpose hydropower reservoir system will be at best goals. The research has a new contribution: The research represents a method to build a rule curve for multi-purpose hydropower reservoir system by combining hydropower reservoir system simulation and global constraint optimization.

Title of the Paper: Size and Cost Optimization of a Renewable Energy Hybrid System


Authors: Anand Singh, Prashant Baredar

Pages: 75-80

Abstract: In this paper sun oriented photovoltaic, Fuel cell, biomass gasifier generator set, battery backup and power conditioning unit have been simulated and optimized for educational institute, energy Centre, Maulana Azad National Institute of Technology, Bhopal in the Indian state of Madhya Pradesh. The area of the study range on the guide situated of 23° 12' N latitude and 77°24'E longitude. In this framework, essential wellspring of power is sun based solar photovoltaic system and biomass gasifier generator set while Fuel cell and batteries are utilized as reinforcement supply. HOMER simulator has been utilized to recreate off grid and it checks the specialized and financial criteria of this hybrid energy system. The execution of every segment of this framework is dissected lastly delicate examination has been performing to enhance the mixture framework at various conditions. In view of the recreation result it is found that the cost of energy (COE) of a biomass gasifier generator set, solar PV and fuel cell crossover energy system has been found to be 15.064 Rs/kWh and complete net present cost Rs.51, 89003. The optimized sizing of 5kW Biomass gasifier generator set, 5kW solar PV, 5kW Fuel cell.

Title of the Paper: Web-based Application for Mapping of the Power Quality Level in the Power Distribution Grids


Authors: Denisa Rusinaru, Leonardo Geo Manescu, Marian Ciontu, Adrian Cojoaca, Miron Alba

Pages: 69-74

Abstract: Poor power quality has negative consequences on the performances of the power networks’ operation. Therefore the efforts of the power grids operators are perfectly justified for finding the best tools for managing and analysis of the power quality (named here PQ). This paper has focused on PQ investigation based on a new type of information report. According to this, the disturbances are reported by using the ranking of PQ levels based on normalized parameters. The paper presents the capabilities of a web-based application designed for mapping of the normalized PQ parameters, as an additional function of the integrate complex system for the management and analysis of PQ data presently operating in the local power distribution grids. This application is developed within a collaboration between the local power grid operator and the power engineering research unit of University of Craiova.

Title of the Paper: Study on Char Recovery from Bottom Coal Ash


Authors: Mihai Cruceru, Bogdan Diaconu, Lucica Anghelescu, Traian Alexandru Abagiu

Pages: 64-68

Abstract: Although Romania has developed electricity generation technologies, the lignite-fired power plants still play a significant role, covering approximately 25% from electricity consumption in Romania. For many years in the past, the lignite-fired power plants used to cover over 40% of power consumption. The major drawback is the generation of large amounts of coal ash. There are 108 ash coal landfills In Romania occupying an area of 2823 ha, the volume of stored coal ash representing several thousand million cubic meters. It is true that a part of coal ash may be reintroduced into the economic circuit by using it in building materials industry. The coal ash presents a valuable oxide composition, a suitable fine grain size, which is a major advantage in the production of building materials by excluding the energy required for grinding. However, despite a large-scale production, only small amounts of coal ash is used currently in Romania in building materials industry. One of the reasons for restricted use of the coal ash is its high carbonaceous content. The coal ash contains appreciable quantities of carbon residues in various forms. The carbon residues may be unreacted coal particles, or char as a result of the chemical transformation of coal in poor oxygen environment. The coal ash used in building material industry must have a low carbon content, usually less than 3,5%, so the carbon residues have to be separated. The carbon residues recovered from the coal ash are currently considered as valuable precursors for absorbents, graphite substitutes or active coal. The paper presents the method that we used for separating and enriching the char by sequentially removing the inorganic matter from bottom coal ash. Very high fixed carbon content in the final product is necessary in order to obtain a valuable graphite precursor.

Title of the Paper: “In situ” Measurements in Energy Saving Building Certificate


Authors: M. Fedorczak-Cisak, M. Furtak

Pages: 50-63

Abstract: Energy-saving building certification is a very important instrument which enables to judge the quality of buildings performance and their real influence on the environment and building users. Access to the European Union forced Poland to implement building standards which take into account reduction of energy consumption. Like in other UE countries there is a high demand to design near zero-energy buildings. The need for evaluation and guarantee that the erected buildings are of proper quality lead Małopolska Center of Energy-saving Buildings (MCBE) to develop energy- saving certificate (named MCBE Certificate). This very first energy – saving building certificate in Poland takes into account local climate conditions, local energy distributors coefficients and local architectural regulations. MCBE certificate indicates three important areas: energy characteristics, carbon footprint (environmental impact) and in situ measurements of buildings connected with their real energy consumption. The first building to have passed the certificate procedure is Malopolska Laboratory of Energy Energy–saving Building (MLBE) in Cracow University of Technology. The first part of the article shows certificate methodology developed in dynamic simulations. The in situ studies which are the basis of issuing MCBE Certificate are presented in the second part of the article. The study of insulating envelope tightness of a building has been described in more detail. It is the most important study which should be carried out before granting a building a certificate proving its energy saving quality. The “in situ” measurements are one of the most important tasks of the Malopolska Centre of Energy Saving Building.

Title of the Paper: New Method and Software for the Round Timber Automatic Measurement


Authors: Artem V. Kruglov, Evgenia V. Shishko, Victoria A. Kozhova, Svetlana G. Zavada

Pages: 42-49

Abstract: This paper is devoted to the description and validation of the round timber volume measurement method on the basis of the photogrammetry analysis of the log pile end images. The method is based on the specialized software which allows user to perform automatic analysis of the images involved abuts detection and determination geometry and orientation of each log in the pile. It is followed by manual edit of the obtained results and final calculation of the log pile cubic capacity according to the piece-by-piece measurement method. The software output was compared against manual piece-by-piece measurement method. Results of two measurement techniques were thoroughly analyzed and visual estimation of their output data showed that algorithm gives a misleading result in cases of abuts with strong elliptical form, however, in other cases its result is more reasonable than manual measurement. According to the testing results the average error of the algorithm for the log pile photogrammetry measurement is less than 9.2%with an average error of 5.14%. Thus, the method of the log piles measurement using the developed algorithm can be successfully applied in the activity of forest enterprises as far as industry standards establish the maximum volume measurement error for the round timber accounting in the range ±12%.

Title of the Paper: Influence of a Control System in an Active Journal Hybrid Bearing on the Energy Parameters of its Operation


Authors: Denis Shutin, Leonid Savin, Roman Polyakov

Pages: 38-41

Abstract: Energy efficiency is an essential parameter of bearings, especially in heavy-duty and complexly loaded rotary machines. Control systems integrated in fluid-film bearings are able to expand the range of operating modes of such systems. It allows searching for modes with lower power losses due to friction than can be reached in convenient passive systems. This study shows influence of the controller type, its settings and setpoint value on such power losses in rotary machines with journal hybrid bearings. The obtained results of the study allow choosing and tuning controllers of such bearings so that power losses due to friction are minimized.

Title of the Paper: Spatial Analysis Methodology for the Italian Coastal Landscape: Features and Dynamics Evolution


Authors: Donatella Cialdea, Luigi Mastronardi

Pages: 24-37

Abstract: This study aims to propose a methodology for the analysis of the Coastal Landscape, especially in relation to the tourism activity. The analysis revealed a high environmental vulnerability due to the strong seasonality of tourism, with negative consequences on soil, biodiversity, water and energy resources. The main problem is the preservation of nature in the Italian coastal areas, and its correlation with the landscape quality aims that new Plans need, in according with the New Code for Cultural and Landscape Heritage. The Authors developed a new multi-criterial approach in order to summarize interaction models for the investigated phenomena, supported by the G.I.S. technologies, implemented in their Laboratory (Laboratory for Activities Connected with Territorial and Environmental Development) in order to develop an innovative spatial analysis that take into account all territory features and all spatial information types, applied to the New Landscape Regional Plan for the Molise Region in the South of Italy, which they are developing.

Title of the Paper: Municipal Sustainable Coastal Governance: Social-Ecological Systems Studies Towards Complementary Instruments


Authors: Raimonds Ernsteins, Ivars Kudrenickis, Anita Lontone-Ievina, Ilga Zilniece, Ingvars Lerhs

Pages: 14-23

Abstract: Municipal sustainable coastal governance (SCG) developments in Latvia have been investigated throughout the whole governance cycle - from understanding and initial applications of social-ecological systems studies approach towards related strategic decisions, policy formulations and planning with next applications of integrated management to be done by complementary introduction and use of the set of six main groups of instruments, and finally, evaluation/assesment work by monitoring/indicator system. Environmental/coastal management instruments have been analyzed, emphasizing approaches of collaboration governance and integration. Both disciplinary and integrative instruments are to be complementary planned/applied and possibly also integrated in order to improve the consequence and coherence (horizontal integration) in-between the various sectors and governance levels (vertical integration). SCG, being of integrative character, require especial attention towards development of collaboration instruments. There are proposed and tested integrated methodology combining all mentioned above into the applied model of collaboration governance in order to be used further on as coastal sience-policy-practice interface for municipal, especially rural, SCG required developments, since research-and-development studies in coastal municipalities are concluding on still existing deficiencies characterizing local coastal stakeholders, being neither satisfactory informed and knowledgable nor aware of integrated coastal problem-solving approaches and instruments.

Title of the Paper: Using Energy Storage for Modeling a Stand-Alone Wind Turbine System


Authors: Cornel Bit

Pages: 9-13

Abstract: This paper presents the modeling in Matlab-Simulink of a stand-alone wind turbine system with energy storage dedicated for small power wind turbines of 3kW with a variable speed permanent magnet synchronous generator (PMSG), diode rectifier bridge, buck-boost converter, bidirectional charge controller, transformer, inverter, ac loads and energy storage devices. Are presented the general system configuration, the Simulink block diagram and the main simulated characteristics resulting from the dynamic performances during the wind speed variation.

Title of the Paper: Research on Ash Pollution Resulting from Coal-Firing Power Plants


Authors: Cristinel Racoceanu, Luminiţa Georgeta Popescu, Mihai Cruceru, Cristinel Popescu

Pages: 5-8

Abstract: This paper presents a case study on pollution with ash resulted by burning lignite in the boilers of power units of 330 MW operating in the Oltenia Energy Complex. Large quantities of ash and slag produced have negative effects on the environmental factors and also on human health. The objectives of the paper were to determine the concentration of heavy metals in ash harvested from surface deposits to depths of 5 to 20m, in groundwater and also to evaluate the dispersion of ash dust. Samples were collected from the Valley Ceplea of the Turceni power plant. The heavy metals concentrations were determined by atomic absorption spectroscopy. In order to assess the ash particles dispersion into the atmosphere, the EMPOLI modeling and simulation software was used. The experimental measurements revealed that 94.98% from ash contains particles of 40 µm. Ash concentration in chimney flue gases (48 mg / Nm3 and 46 mg / Nm3) comply with the maximum permissible limit of 50 mg / Nm3. Ash particle dispersion calculated showed that hourly concentrations of total suspended particles do not exceed the maximum permissible concentration. Soil and groundwater pollution tests have shown that the heavy metals contained in the ash are normal for Cd, Co, Zn, exceed normal levels for Cu, Ni, Pb and in leachate samples was solubilized only Cd with values within the limits imposed in NTPA 001/2001.

Title of the Paper: Environmental Impact of Coal-Based Power Plants Slag and Ash Deposits Through Mass Transfer on Subsoil


Authors: Cornelia A. Bulucea, Andreea C. Jeles, Carmen A. Bulucea

Pages: 1-4

Abstract: The toxins specific to slag and ash deposits through the environmental xenobiotics induce malignant tumors of high incidence rate. Within the framework of sustainable development the environmental and technical issues are linked. In line with this idea it is important to build mathematical models that reflect how the transfer into the subsoil of a toxic dose from a slag and ash deposit source on ground is realized. Identification of such a mathematical model to process the data of mass transfer type could allow relevant conclusions on the interaction polluter - geographic area. This paper presents a case study based on the scenario of the transfer of a toxic dose in the subsoil from the slag and ash deposit on the ground of Isalnita power plant located in Oltenia region, Romania. Taking into consideration the spatial distribution of soil structure in depth it is analyzed the toxic mass transfer into the subsoil based on two scenarios, namely the linear and nonlinear distribution of mass transfer. Based on linear and, respectively nonlinear mathematical models there are performed numerical simulations of toxic mass transfer into the subsoil.