International Journal of Renewable Energy Technology http://www.inderscience.com/browse/index.php?journalID=317&year=2012&vol=3&issue=1 Inderscience Publishers Ltd en-uk International Journal of Renewable Energy Technology 1757-3971 1757-398X © 2012 Inderscience Publishers Ltd editor@inderscience.com https://www.inderscience.com/images/files/coverImgs/ijret_scoverijret.jpg http://www.inderscience.com/browse/index.php?journalID=317&year=2012&vol=3&issue=1 http://www.inderscience.com/link.php?id=43904 This paper presents the performance of solar tunnel dryer to dry chemically untreated grape. Average air temperature rise in dryer was in the range of 20-21°C above the ambient temperature and it was almost constant in the dryer. The solar tunnel dryer of size 10 × 3.75 m² is in position to dry 320 kg of grapes from 85% (wb) moisture content to 16% (wb) moisture content within seven days. Developed solar dryer works at temperature between 55-70°C, therefore, there is scope for saving conventional fuel by adoption of solar energy-based drying operation. Performance evaluation of solar tunnel dryer for grape drying
N.S. Rathore; N.L. Panwar; Bhawana Asnani
International Journal of Renewable Energy Technology, Vol. 3, No. 1 (2012) pp. 1 - 10
This paper presents the performance of solar tunnel dryer to dry chemically untreated grape. Average air temperature rise in dryer was in the range of 20-21°C above the ambient temperature and it was almost constant in the dryer. The solar tunnel dryer of size 10 × 3.75 m² is in position to dry 320 kg of grapes from 85% (wb) moisture content to 16% (wb) moisture content within seven days. Developed solar dryer works at temperature between 55-70°C, therefore, there is scope for saving conventional fuel by adoption of solar energy-based drying operation.

]]> 10.1504/IJRET.2012.043904 International Journal of Renewable Energy Technology, Vol. 3, No. 1 (2012) pp. 1 - 10 N.S. Rathore; N.L. Panwar; Bhawana Asnani College of Dairy and Food Science Technology, Maharana Pratap University of Agriculture and Technology, Udaipur (Rajasthan) 313 001, India. ' Department of Renewable Energy Sources, College of Technology and Engineering, Maharana Pratap University of Agriculture and Technology, Udaipur (Rajasthan) 313 001, India. ' College of Dairy and Food Science Technology, Maharana Pratap University of Agriculture and Technology, Udaipur (Rajasthan) 313 001, India solar tunnel dryer grape drying drying rate moisture content chemically untreated grapes solar energy solar power renewable energy. 2011-12-01T23:20:50-05:00 3 1 1 10 2011-12-01T23:20:50-05:00 http://www.inderscience.com/link.php?id=43905 Nowadays for solar heating applications, usage of phase change materials (PCM) to store the heat in the form of latent heat is increased, because large quantity of thermal energy is stored in small volume. The present experimental investigation on the thermal energy storage (TES) system is developed using paraffin and stearic acid as PCM. In the present system solar energy is used as heat source to store the thermal energy in the form of sensible heat and latent heat. In the TES system paraffin and stearic acid are stored in the form of spherical capsules of 38 mm diameter. Investigation results related to the charging time and recovery of stored energy are presented. The experimental investigation showed that the charging and recovery of storage energy are less affected by the PCM materials (paraffin and stearic acid). But, utilisation of stearic acid as PCM is more economical without affecting the quantity of thermal energy stored, charging time and recovery of the stored thermal energy. Solar energy based thermal energy storage system using phase change materials
R. Meenakshi Reddy; N. Nallusamy; T. Hariprasad; K. Hemachandra Reddy; G. Ramachandra Reddy
International Journal of Renewable Energy Technology, Vol. 3, No. 1 (2012) pp. 11 - 23
Nowadays for solar heating applications, usage of phase change materials (PCM) to store the heat in the form of latent heat is increased, because large quantity of thermal energy is stored in small volume. The present experimental investigation on the thermal energy storage (TES) system is developed using paraffin and stearic acid as PCM. In the present system solar energy is used as heat source to store the thermal energy in the form of sensible heat and latent heat. In the TES system paraffin and stearic acid are stored in the form of spherical capsules of 38 mm diameter. Investigation results related to the charging time and recovery of stored energy are presented. The experimental investigation showed that the charging and recovery of storage energy are less affected by the PCM materials (paraffin and stearic acid). But, utilisation of stearic acid as PCM is more economical without affecting the quantity of thermal energy stored, charging time and recovery of the stored thermal energy.

]]> 10.1504/IJRET.2012.043905 International Journal of Renewable Energy Technology, Vol. 3, No. 1 (2012) pp. 11 - 23 R. Meenakshi Reddy; N. Nallusamy; T. Hariprasad; K. Hemachandra Reddy; G. Ramachandra Reddy Department of Mechanical Engineering, Sri Venkateswara College of Engineering and Technology, Chittoor, Andra Pradesh, 517127, India. ' Department of Mechanical Engineering, Sri Venkateswara College of Engineering, Post Bag No. 3, Pennalur, Sriperumbudur Tamil Nadu, 602 105, India. ' Department of Mechanical Engineering, Sri Venkateswara College of Engineering and Technology, Chittoor, Andra Pradesh, 517127, India. ' JNTU College of Engineering, Anantapur, Andra Pradesh, 515002, India. ' Malla Reddy College of Engg. for Women, Suraram 'X' Road, Quthubullapur Municipality, Hyderabad, India heat transfer fluids HTF paraffin phase change materials PCM stearic acid thermal energy storage TES solar energy solar power solar heating latent heat renewable energy. 2011-12-01T23:20:50-05:00 3 1 11 23 2011-12-01T23:20:50-05:00 http://www.inderscience.com/link.php?id=43906 In this paper, particle swarm optimisation (PSO) technique is employed to determine the optimal operating point of a photovoltaic module used in a stand-alone PV system. The PSO algorithm identifies the maximum power point by determining the array voltage at maximum point (V<SUP align="right">MPP</SUP>). This value is utilised as a reference value to a voltage controller to adjust the duty cycle of a boost converter such that the PV operating point is forced to operate at the maximum power point. The obtained results demonstrated the advantages of the proposed tracking system in terms of high tracking efficiency and relatively low convergence time. Moreover, the proposed method is compared to some other tracking methods. The results indicate that the method is reliable and accurate. Optimal operating point tracking in a stand-alone PV system using particle swarm optimisation
Mohamed Azab
International Journal of Renewable Energy Technology, Vol. 3, No. 1 (2012) pp. 24 - 35
In this paper, particle swarm optimisation (PSO) technique is employed to determine the optimal operating point of a photovoltaic module used in a stand-alone PV system. The PSO algorithm identifies the maximum power point by determining the array voltage at maximum point (V<SUP align="right">MPP</SUP>). This value is utilised as a reference value to a voltage controller to adjust the duty cycle of a boost converter such that the PV operating point is forced to operate at the maximum power point. The obtained results demonstrated the advantages of the proposed tracking system in terms of high tracking efficiency and relatively low convergence time. Moreover, the proposed method is compared to some other tracking methods. The results indicate that the method is reliable and accurate.

]]> 10.1504/IJRET.2012.043906 International Journal of Renewable Energy Technology, Vol. 3, No. 1 (2012) pp. 24 - 35 Mohamed Azab Electrical Engineering Technology Department, Benha High Institute of Technology, Benha University, P.O. Box 13512, Benha-Kalubiyah, Egypt; Electrical and Electronic Engineering Department, Yanbu Industrial College-YIC, P.O. Box 30436, Yanbu AL-Sinaiyah, Saudi Arabia renewable energy PV arrays particle swarm optimisation PSO boost converters photovoltaic arrays tracking efficiency convergence time solar energy solar power. 2011-12-01T23:20:50-05:00 3 1 24 35 2011-12-01T23:20:50-05:00 http://www.inderscience.com/link.php?id=43907 Wind energy conversion systems (WECS) have merits as environmentally friendly and renewable sources of energy. Because of its stochastic variations, power management concepts are essential to extract as much power as possible from the wind when it becomes available. The purpose of this paper is to present a TSK fuzzy model, which represents the turbine characteristic for maximum power point tracking (MPPT) in WECS. The proposed TSK fuzzy model allows the generator to track the optimal operation points of the wind turbine system under fluctuating wind conditions. This model does not require the knowledge of the wind speed. The TSK fuzzy model identification is based on subtractive clustering and least squares methods. A fuzzy logic controller is compared to a conventional PI controller in regulating the generator rotor speed. The fuzzy controller can cope with more operating conditions with improved performance. Maximum power point tracking for wind energy conversion systems based on fuzzy modelling and control
Ayman Francees; Abdel-Latif Elshafei
International Journal of Renewable Energy Technology, Vol. 3, No. 1 (2012) pp. 36 - 57
Wind energy conversion systems (WECS) have merits as environmentally friendly and renewable sources of energy. Because of its stochastic variations, power management concepts are essential to extract as much power as possible from the wind when it becomes available. The purpose of this paper is to present a TSK fuzzy model, which represents the turbine characteristic for maximum power point tracking (MPPT) in WECS. The proposed TSK fuzzy model allows the generator to track the optimal operation points of the wind turbine system under fluctuating wind conditions. This model does not require the knowledge of the wind speed. The TSK fuzzy model identification is based on subtractive clustering and least squares methods. A fuzzy logic controller is compared to a conventional PI controller in regulating the generator rotor speed. The fuzzy controller can cope with more operating conditions with improved performance.

]]> 10.1504/IJRET.2012.043907 International Journal of Renewable Energy Technology, Vol. 3, No. 1 (2012) pp. 36 - 57 Ayman Francees; Abdel-Latif Elshafei Electrical and Computer Department, Faculty of Engineering Sciences, Sinai University, North Sinai Al Arish Al Masaid, Egypt. ' Electric Power and Machines Department, Faculty of Engineering, Cairo University, Giza 12613, Egypt wind energy conversion systems WECS maximum power point tracking MPPT fuzzy modelling fuzzy PI controllers fuzzy control wind power renewable energy fuzzy logic generator rotor speed. 2011-12-01T23:20:50-05:00 3 1 36 57 2011-12-01T23:20:50-05:00 http://www.inderscience.com/link.php?id=43909 In this paper, a new robust controller has been proposed for attaining the maximum safe instantaneous wind penetration. Particle swarm optimisation (PSO)-based algorithm has been developed to obtain the maximum safe instantaneous penetration by the optimisation of grid parameters. The developed algorithm has been tested on modified IEEE 14-bus system. The effectiveness of the proposed methodology has been shown in terms of maximum instantaneous safe wind energy penetration limit, in percentage and also maximum safe bus loading point, explicitly beyond which system drives into instability. Development of PSO-based robust controller for maximising wind penetration
Sasidharan Sreedharan; Weerakorn Ongsakul; Jai Govind Singh; S.S. Mahapatra
International Journal of Renewable Energy Technology, Vol. 3, No. 1 (2012) pp. 58 - 78
In this paper, a new robust controller has been proposed for attaining the maximum safe instantaneous wind penetration. Particle swarm optimisation (PSO)-based algorithm has been developed to obtain the maximum safe instantaneous penetration by the optimisation of grid parameters. The developed algorithm has been tested on modified IEEE 14-bus system. The effectiveness of the proposed methodology has been shown in terms of maximum instantaneous safe wind energy penetration limit, in percentage and also maximum safe bus loading point, explicitly beyond which system drives into instability.

]]> 10.1504/IJRET.2012.043909 International Journal of Renewable Energy Technology, Vol. 3, No. 1 (2012) pp. 58 - 78 Sasidharan Sreedharan; Weerakorn Ongsakul; Jai Govind Singh; S.S. Mahapatra Energy Field of Study, School of Environment Resources and Development, Asian Institute of Technology, Bangkok 12120, Thailand. ' Energy Field of Study, School of Environment Resources and Development, Asian Institute of Technology, Bangkok 12120, Thailand. ' Energy Field of Study, School of Environment Resources and Development, Asian Institute of Technology, Bangkok 12120, Thailand. ' Energy Field of Study, School of Environment Resources and Development, Asian Institute of Technology, Bangkok 12120, Thailand wind power generation wind penetration power system modelling robust control Weibull distribution renewable energy technology particle swarm optimisation PSO wind energy safety. 2011-12-01T23:20:50-05:00 3 1 58 78 2011-12-01T23:20:50-05:00 http://www.inderscience.com/link.php?id=43913 Energy and exergy audit of a solar grain dryer has been presented in this paper. The solar grain dryer is made up of a flat-plate solar collector and a convective drying chamber. The properties of the working fluid were measured at various energy input levels. Energy and exergy balance equations were written for the flat-plate solar collector, the convective drying chamber and the solar grain dryer. The audit performance equations were developed based on the energy and exergy balances in the solar grain dryer. The audit performance results show that the higher the energy loss and exergy destruction, the lower the values of energy and the exergy efficiencies in the solar grain dryer. The audit performance results obtained are useful for the design of an efficient grain solar dryer. Energy and exergy audit of a solar grain dryer
C.O.C. Oko; S.N. Nnamchi
International Journal of Renewable Energy Technology, Vol. 3, No. 1 (2012) pp. 79 - 93
Energy and exergy audit of a solar grain dryer has been presented in this paper. The solar grain dryer is made up of a flat-plate solar collector and a convective drying chamber. The properties of the working fluid were measured at various energy input levels. Energy and exergy balance equations were written for the flat-plate solar collector, the convective drying chamber and the solar grain dryer. The audit performance equations were developed based on the energy and exergy balances in the solar grain dryer. The audit performance results show that the higher the energy loss and exergy destruction, the lower the values of energy and the exergy efficiencies in the solar grain dryer. The audit performance results obtained are useful for the design of an efficient grain solar dryer.

]]> 10.1504/IJRET.2012.043913 International Journal of Renewable Energy Technology, Vol. 3, No. 1 (2012) pp. 79 - 93 C.O.C. Oko; S.N. Nnamchi Mechanical Engineering Department, Faculty of Engineering, University of Port Harcourt, PMB 5323, Port Harcourt, Nigeria. ' Mechanical Engineering Department, Faculty of Engineering, University of Port Harcourt, PMB 5323, Port Harcourt, Nigeria energy audit exergy audit renewable energy solar grain dryers flat-plate collectors convective drying chambers solar energy solar power. 2011-12-01T23:20:50-05:00 3 1 79 93 2011-12-01T23:20:50-05:00 http://www.inderscience.com/link.php?id=43914 Neat vegetable oils as fuels for diesel engines give rise to engine performance and durability problems due to the differences in some of the properties between vegetable oils and diesel. The objective of the present work was to improve the performance of mahua oil fuelled diesel engine using hydrogen enriched air. Mahua oil was used as the main fuel in a direct injection diesel engine and hydrogen enriched air was supplied at different flow rates through a gas carburetor. The performance and emission parameters of the dual fuel engine were studied at different loads and compared with corresponding base line diesel and mahua oil fuelled operating conditions. Mahua oil combustion with varying quantities of hydrogen (10 lpm, 20 lpm, 30 lpm, 40 lpm and 50 lpm) enriched air resulted in improvement in brake thermal efficiency and reduction in smoke density. The maximum thermal efficiency was recorded at 40 lpm hydrogen enrichment. Hydrogen enrichment was found to increase the combustion rate of mahua oil. The NOX concentration was higher for mahua oil operation with hydrogen enrichment; but lower than diesel. Effect of hydrogen enriched air on the performance and emissions of mahua oil fuelled diesel engine
G. Sankaranarayanan; M. Pugazhvadivu
International Journal of Renewable Energy Technology, Vol. 3, No. 1 (2012) pp. 94 - 106
Neat vegetable oils as fuels for diesel engines give rise to engine performance and durability problems due to the differences in some of the properties between vegetable oils and diesel. The objective of the present work was to improve the performance of mahua oil fuelled diesel engine using hydrogen enriched air. Mahua oil was used as the main fuel in a direct injection diesel engine and hydrogen enriched air was supplied at different flow rates through a gas carburetor. The performance and emission parameters of the dual fuel engine were studied at different loads and compared with corresponding base line diesel and mahua oil fuelled operating conditions. Mahua oil combustion with varying quantities of hydrogen (10 lpm, 20 lpm, 30 lpm, 40 lpm and 50 lpm) enriched air resulted in improvement in brake thermal efficiency and reduction in smoke density. The maximum thermal efficiency was recorded at 40 lpm hydrogen enrichment. Hydrogen enrichment was found to increase the combustion rate of mahua oil. The NOX concentration was higher for mahua oil operation with hydrogen enrichment; but lower than diesel.

]]> 10.1504/IJRET.2012.043914 International Journal of Renewable Energy Technology, Vol. 3, No. 1 (2012) pp. 94 - 106 G. Sankaranarayanan; M. Pugazhvadivu Mechanical Engineering Department, Adhiparasakthi Engineering College, Melmaruvathur, Kancheepuram 603 319, Tamilnadu, India. ' Mechanical Engineering Department, Pondicherry Engineering College, Puducherry 605 014, India mahua oil hydrogen enriched air dual fuel engines engine performance engine emissions direct injection diesel engines alternative fuel neat vegetable oils gas carburetors brake thermal efficiency smoke density hydrogen enrichment combustion rate NOX emissions vehicle braking renewable energy. 2011-12-01T23:20:50-05:00 3 1 94 106 2011-12-01T23:20:50-05:00