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Aims and Scope
Editorial Board

1. Prospects of concentrating solar power to deliver key energy services in a developing country

Charikleia Karakosta, Charalampos Pappas, John Psarras

National Technical University of Athens, School of Electrical and Computer Engineering, Management & Decision Support Systems Lab (NTUA-EPU), 9, Iroon Polytechniou str., 15780, Athens, Greece.

Abstract: One of today’s greatest challenges is the response to the worldwide continuously increasing energy demand. The need for supply of electricity is getting greater year by year. In addition, climate change problems and the limited fossil resources require new sustainable electricity generation options, which utilize Renewable Energy Sources (RES) and are economical in the meantime. Concentrating Solar Power (CSP) generation is a proven renewable energy technology that has the potential to become cost-effective in the future. This analysis explores for Chile the potential of CSP to deliver key energy services for the country. The specific technology has a significant technical potential within Chile, but ‘somehow’ do not receive sufficient attention from relevant stakeholders, because of gaps either in stakeholders’ awareness of the technology or in domestic research and development (R&D) and/or public/private investment. The aim of this paper is to establish a well-informed discussion on the feasibility and potential of the specific sustainable energy technology, namely the CSP technology, within a given country context and particularly Chile. It provides an overview of the fundamental (macro-economic) forces within an economy and identifies some of the blockages and barriers that can be expected when introducing a new technology.

Volume 2, Issue 5, 2011, pp.771-782.

2. Experimental investigations and CFD study of temperature distribution during oscillating combustion in a crucible furnace

J. Govardhan¹, G.V.S. Rao², J. Narasaiah³

1 Department of Mechanical Engineering, AVN Institute of Engineering & Technology, A.P., India.

2 Department of Mechanical Engineering, PIRM Engineering College, A.P., India.

3 Department of Mechanical Engineering, PRRM Engineering College, A.P., India.

Abstract: As part of an investigation few experiments were conducted to study the enhanced heat transfer rate and increased furnace efficiency in a diesel fired crucible furnace with oscillating combustion. The results of experimental investigations of temperature distribution inside the crucible furnace during oscillating combustion are validated with the numerical simulation CFD code. At first pragmatic study of temperature distribution inside a furnace was carried out with conventional mode of combustion at certain conditions and later transient behavior similar to that is conducted with oscillating combustion mode with the same conditions. There found to be enhanced heat transfer rate, reduced processing time and increased furnace efficiency with visibly clean emissions during the oscillating combustion mode than the conventional combustion mode. In the present paper the temperatures inside the furnace at few designated points measured by suitable K type thermo-couples are compared with the CFD code. The geometric models were created in ANSYS and the configuration was an asymmetric one for computational reason. The experimental and numerical investigations produce similar acceptable results. The presented results show that the 3D transient model appeared to be an effective numerical tool for the simulation of the crucible furnace for melting processes.

3. Cooling load and COP optimization of an irreversible Carnot refrigerator with spin-1/2 systems

Xiaowei Liu¹, Lingen Chen¹, Feng Wu^1,2, Fengrui Sun¹

1 College of Naval Architecture and Power, Naval University of Engineering, Wuhan 430033, P. R. China.

2 School of Science, Wuhan Institute of Technology, Wuhan 430074, P. R. China.

Abstract: A model of an irreversible quantum refrigerator with working medium consisting of many non-interacting spin-1/2 systems is established in this paper. The quantum refrigeration cycle is composed of two isothermal processes and two irreversible adiabatic processes and is referred to as a spin quantum Carnot refrigeration cycle. Expressions of some important performance parameters, such as cycle period, cooling load and coefficient of performance (COP) for the irreversible spin quantum Carnot refrigerator are derived, and detailed numerical examples are provided. The optimal performance of the quantum refrigerator at high temperature limit is analyzed with numerical examples. Effects of internal irreversibility and heat leakage on the performance are discussed in detail. The endoreversible case, frictionless case and the case without heat leakage are discussed in brief.

4. Optimal cost and allocation for UPFC using HRGAPSO to improve power system security and loadability

Marouani I., Guesmi T., Hadj Abdallah H., Ouali A.

Sfax Engineering National School, Electrical Department, BP: W, 3038 Sfax-Tunisia.

Abstract: With the electricity market deregulation, the number of unplanned power exchanges increases. Some lines located on particular paths may become overload. It is advisable for the transmission system operator to have another way of controlling power flows in order to permit a more efficient and secure use of transmission lines. The FACTS devices (Flexible AC Transmission Systems) could be a mean to carry out this function. In this paper, unified power flow controller (UPFC) is located in order to maximize the system loadability and index security. The optimization problem is solved using  a new evolutionary learning algorithm based on a hybrid of real genetic algorithm (RGA) and particle swarm optimization (PSO) called HRGAPSO. The Newton-Raphson load flow algorithm is modified to consider the insertion of the UPFC devices in the network. Simulations results validate the efficiency of this approach to improvement in security, reduction in losses of power system, minimizing the installation cost of UPFC and increasing power transfer capability of the existing power transmission lines. The optimization results was performed on 14-bus test system and implemented using MATLAB.

5. Online performance assessment of heat exchanger using artificial neural networks

C. Ahilan¹, S. Kumanan¹, N. Sivakumaran²

1 Department of Production Engineering, National Institute of Technology Tiruchirappalli, India.

2 Department of Instrumentation and Control Engineering, National Institute of Technology Tiruchirappalli, India.

Abstract: Heat exchanger is a device in which heat is transferred from one medium to another across a solid surface. The performance of heat exchanger deteriorates with time due to fouling on the heat transfer surface. It is necessary to assess periodically the heat exchanger performance, in order to maintain at high efficiency level. Industries follow adopted practices to monitor but it is limited to some degree. Online monitoring has an advantage to understand and improve the heat exchanger performance. In this paper, online performance monitoring system for shell and tube heat exchanger is developed using artificial neural networks (ANNs). Experiments are conducted based on full factorial design of experiments to develop a model using the parameters such as temperatures and flow rates. ANN model for overall heat transfer coefficient of a design/ clean heat exchanger system is developed using a feed forward back propagation neural network and trained. The developed model is validated and tested by comparing the results with the experimental results. This model is used to assess the performance of heat exchanger with the real/fouled system. The performance degradation is expressed using fouling factor (FF), which is derived from the overall heat transfer coefficient of design system and real system. It supports the system to improve the performance by asset utilization, energy efficient and cost reduction interms of production loss.

6. Energy efficiency and cost analysis of canola production in different farm sizes

S. H. Mousavi-Avval, S. Rafiee, A. Jafari, A. Mohammadi

Department of Agricultural Machinery Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj, Iran.

Abstract: Efficient use of energy in agriculture is one of the conditions for sustainable agricultural production. The aims of this study were to determine the amount of input–output energy used in canola production, to investigate the efficiency of energy consumption and to make an economic analysis of canola production in different farm sizes. Data used in this study were obtained from 130 randomly selected farms in Golestan province, the most important centre of oilseed production in Iran. The surveyed farms were classified into three groups of small (less than 2 ha), medium (2 to 4 ha) and large farms (more than 4 ha). The results revealed that total energy input for canola production increased from 15817.24 MJ ha-1, in small farms, to 20663.13 MJ ha-1, in large farms; while, the highest yield value (2286.36 kg ha-1) was obtained from medium farms. The results also revealed that the medium farms had the highest energy use efficiency (3.75) and benefit to cost ratio (1.59); indicating a better management of energy and input consumptions in these farms. Moreover, the energy use efficiency for small and large farms was found to be 3.35 and 3.07, respectively.

7. Multi criteria analysis in environmental management: Selecting the best stormwater erosion and sediment control measure in Malaysian construction sites

Ibrahiem Abdul Razak Al-Hadu¹, Lariyah Mohd Sidek¹, Mohamed Nor Mohamed Desa¹, Noor Ezlin Ahmad Basri²

1 Civil Engineering, Universiti Tenaga Nasional, Kajang, Selangor, Malaysia.

2 Civil & Structural Engineering, Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia.

Abstract: Malaysia located in a tropical region which is interested with a heavy rainfall through the whole seasons of the year. Construction stages usually associated with soil disturbing due to land clearing and grading activities, this combined with the tropical climate in Malaysia, will generate an enormous amount of soil to be eroded and then deposited in the adjacent water bodies. There are many kinds of mitigation measures used so as to reduce the impact of erosion and sedimentation that are generated due to the stormwater in construction sites. This paper presents the application of Multi Criteria Analysis (MCA) tool in choosing the best stormwater control measure by depending on specified criteria and criterion weight. The results obtained from the application of MCA in stormwater pollution control have many benefits to the contractors, consultants and decision makers by making them able to select the best control measure for every stage of construction.

8. A capillary-based method determining the permeability of sand layer for geothermal applications

Huajun Wang, Hongjie Zhao, Chengying Qi

School of Energy and Environment Engineering, Hebei University of Technology, Tianjin, China.

Abstract: The hydraulic permeability is a major parameter for modelling the heat transfer of borehole heat exchangers (BHEs) in an aquifer, where the groundwater advection has a significant impact on the thermal performance of BHEs. This paper presented a novel method determining the hydraulic permeability of sand layer using the theory of capillary rise (CR). In this method, based on the observation on the dynamic CR process, the equilibrium height together with the fluid velocity was determined by the steepest descent method to calculate the hydraulic permeability. Further, a laboratory experimental setup was built to measure the hydraulic permeability of screened dry sand with different grain diameters. The measured results were in a good agreement with the predictions by other theoretical models. Finally, the effects of the filling height and immersion depth of the capillary tube on the test accuracy were discussed. The present method can also be applied for other porous materials with the grain diameter of 0.1-0.6mm.

9. Enhancement of emission characteristics of a direct injection diesel engine through porous medium combustion technique

C. Kannan¹, P. Tamilporai²

1 Department of Automobile Engineering, Sri Venkateswara College of Engineering, Anna University Chennai, India.

2 Department of Mechanical Engineering, Anna University Chennai, India.

Abstract: In this research work, a direct injection diesel engine with the implementation of porous medium combustion technique has been investigated for performance and emission characteristics. The porous medium combustion technique has been established in the present work by the introduction of porous ceramic material into the combustion chamber. The nitrogen oxide and soot emission of porous medium engine are found to be lower to that of conventional engine. However the soot emissions are higher in the porous medium engine under part load conditions

10. MPPT control of wind generation systems based on FNN with PSO algorithm

Chih-Ming Hong¹, Whei-Min Lin¹, Chiung-Hsing Chen², Ting-Chia Ou³

1 Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan, R.O.C.

2 Electronic Communication Engineering, National Kaohsiung Marine University, Kaohsiung 81157, Taiwan, R.O.C.

3 Institute of Nuclear Energy Research, Atomic Energy Council, Taoyuan 32546, Taiwan, R.O.C.

Abstract: This paper presents the design of an on-line training fuzzy neural network (FNN) using back-propagation learning algorithm with particle swarm optimization (PSO) regulating controller for the induction generator (IG). The PSO is adopted in this study to adapt the learning rates in the back-propagation process of the FNN to improve the learning capability. The proposed output maximization control is achieved without mechanical sensors such as the wind speed or position sensor, and the new control system will deliver maximum electric power with light weight, high efficiency, and high reliability. The estimation of the rotor speed is designed on the basis of the sliding mode control theory.

11. Status and prospects for household biogas plants in Ghana – lessons, barriers, potential, and way forward

Edem Cudjoe Bensah¹, Moses Mensah², Edward Antwi³

1 Chemical Engineering Department, Kumasi Polytechnic, Kumasi, Ghana.

2 Chemical Engineering Department, KNUST, PMB, Kumasi, Ghana.

3 Mechanical Engineering Department, Kumasi Polytechnic, Kumasi, Ghana.

Abstract: Ghana is a country faced with pressing developmental challenges on energy, sanitation, environment and agriculture. The development of a large scale, enterprise-based biogas programme in Ghana will improve sanitation, produce clean energy, reduce greenhouse gas emissions, promote nutrient recovery, and create jobs. While aforementioned benefits of biogas are known, the biogas industry is still not growing at rates that would enable its impact on sanitation, agriculture and energy usage to be felt, owing to challenges such as low awareness creation and poor biogas supply chain, lack of well-trained personnel, poor follow-up services, and high cost of biogas digesters – USD 235- 446 per cubic meter. This paper looks at the chronology of biogas developmental in Ghana, technical and market potential of household biogas plants, strengths and weaknesses of main biogas service providers, human resource development, quality issues, and risks involved in developing a large scale household biogas programme. From the paper, the technical and market potential of dung-based, household biogas digesters in Ghana are estimated at 162,066 and 16,207 units respectively. In order to take full advantage of biogas technology, the paper recommends the development of standardized digesters, increase in awareness programmes on the life-long benefits of biogas systems, introduction of flexible payment schemes, and stepping-up of follow-up services. Finally, there is an urgent need for a ‘promoter’ who will engage all stakeholders to ensure that a national action plan on biogas technology is initiated and implemented.

12. Performance and emission characteristics of diesel engine run on biofuels based on experimental and semi analytical methods

Donepudi Jagadish, Puli Ravi Kumar, K. Madhu Murhty

Department of Mechanical Engineering, National Institute of Technology, Warangal, Andhra Pradesh-506004, India.

Abstract: Performance and emissions from a constant speed single cylinder diesel engine was observed with different kinds of fuels blends like diesel-ethanol, and diesel-palm stearin methyl ester. The engine setup was modified to operate in different modes like naturally aspirated condition, supercharged condition and with exhaust gas recirculation (EGR). The air fuel ratio was predicted from exhaust emission data using correlations and the particulate matter (PM) was estimated from smoke data. Fuel air equivalence ratio values of the engine at different operating conditions have been compared. Engine is operated with higher fuel air equivalence ratios with EGR. Particulate matter emissions were considerably reduced with ethanol-diesel, biodiesel-diesel blends in comparison to pure diesel. With EGR rate the particulate matter emissions are increased. An EGR rate of 10% will be best for the present engine which can give better trade-off among HC, NOx and PM.

13. Ecological optimization of endoreversible chemical engines

Dan Xia^1,2, Lingen Chen¹, Fengrui Sun¹

1 College of Naval Architecture and Power, Naval University of Engineering, Wuhan 430033, P R China.

2 92957 troop, Zhoushan 316000, P R China.

Abstract: Optimal ecological performances of endoreversible chemical engine cycles with both linear and diffusive mass transfer laws are derived by taking an ecological optimization criterion as the objective, which consists of maximizing a function representing the best compromise between the power output and entropy production rate of the chemical engines. Numerical examples are given to show the effects of mass-reservoir chemical potential ratio and mass-transfer coefficient ratio on the ecological function versus the efficiency characteristic of the cycles. The results can provide some theoretical guidelines for the design of practical chemical engines.

14. Comparative thermal analysis of theoretical and experimental studies of modified indirect evaporative cooler having cross flow heat exchanger with one fluid mixed and the other unmixed

Trilok Singh Bisoniya¹, S.P.S. Rajput², Anil Kumar³

1 Department of Mechanical Engineering, Sagar Institute of Research & Technology, Ayodhya Bypass Road, Bhopal, 462041 - India.

2 Department of Mechanical Engineering, Maulana Azad National Institute of Technology, Bhopal, 462051 - India.

3 Department of Energy, Maulana Azad National Institute of Technology, Bhopal, 462051 - India.

Abstract: The comparative thermal analysis of theoretical and experimental studies of modified indirect evaporative cooler having cross flow heat exchanger with one fluid mixed and the other unmixed is presented in this research paper. A heat and mass transfer mathematical model is developed to simulate the properties of indirect evaporative cooler. The theoretical result analysis was done by plotting the curves between various performance parameters. This work presents the fabrication and experiments carried out on the indirect evaporative cooler at various outdoor air conditions. The data acquired by experiment were analyzed by plotting the curves between various performance parameters. The theoretical and experimental results were compared and analyzed. The theoretical model can be used to predict the performance of modified indirect evaporative cooler.

15. Energy storage in field operations of sunflower production using data envelopment analysis approach

S. H. Mousavi-Avval, S. Rafiee, A. Jafari, A. Mohammadi

Department of Agricultural Machinery Engineering, Faculty of Agricultural, Engineering and Technology, University of Tehran, Karaj, Iran.

Abstract: This study applies a Data Envelopment Analysis (DEA) approach to analyze the technical and scale efficiencies of farmers with respect to energy use for oilseed sunflower production in Golestan province, Iran. This study also helps to segregate the efficient and inefficient farmers, identify the wasteful usage of energy by inefficient farmers and to suggest reasonable saving of energy. The results revealed that total operational energy of 6771.1 MJ ha-1 was consumed for sunflower production and the irrigation operations had the highest share. About 64% of farmers were technically efficient and the mean efficiency of farmers was found to be 0.85 and 0.94 under constant and variable returns to scale assumptions, respectively. The results also revealed that, by raising the performance of inefficient farmers to the highest level, on average, about 9.3% of total operational input energy could be saved. Moreover, energy saving from irrigation operation had the highest share (76.9%). From this study improvement of timing, amount, and reliability of water applications and utilization of new irrigation systems with high efficiency is suggested to improve the energy use efficiency and to reduce the environmental impacts.

16. Effect of heat source on MHD free convection flow past an oscillating porous plate in the slip flow regime

S. S. Das¹, L. K. Mishra², P. K. Mishra³

1 Department of Physics, K B D A V College, Nirakarpur, Khurda-752 019 (Orissa), India.

2 Department of Physics, Sri Sathya Sai College for Women, Bhubaneswar, Khurda -751 030 (Orissa), India.

3 Department of Physics, P N College, Bolgarh, Nayagarh-752 066 (Orissa), India.

Abstract: This paper investigates the effect of heat source on free convective flow of a viscous incompressible electrically conducting fluid through a porous medium bounded by an oscillating porous plate in the slip flow regime in presence of a transverse magnetic field. The governing equations of the flow field are solved analytically and the expressions for velocity, temperature, skin friction t and the heat flux in terms of Nusselts number Nu are obtained. The effects of the important flow parameters such as magnetic parameter M, permeability parameter Kp, Grashof number for heat transfer Gr, heat source parameter S and rarefaction parameter R on the velocity of the flow field are analyzed quantitatively with the help of figures.