International Journal of Renewable Energy Technology (39 papers in press)
Selection of the best barrier solutions for liquid displacement gas collecting meter to prevent gas solubility in microbial electrolysis cells (MECs)
by Abudukeremu Kadier, K. Chandrasekhar, Mohd Sahaid Kalil
Abstract: Microbial Electrolysis Cells (MECs) are a novel technology aiming at producing hydrogen from biomass or wastewater. The collection and preservation of the gas generated in the MECs is the first and most important operation in gas measuring techniques. There are several techniques for the quantitative evaluation of gas production in MECs, such as owen method, respirometer, and gas bag methods. However, the costs associated with these methods could make MEC technology scale-up expensive and impractical. This work describes evaluation of commonly used biogas measurement techniques and analyzes potential errors associated with liquid displacement gas measurement. Inaccuracy mainly due to CO2, and CH4 dilution in displaceable liquids was evaluated by testing solubility of CO2 in twelve different barrier solutions. 95% saturated NaCl (pH 0.5) solution exhibited lower CO2 solubility among the tested solutions. These results indicate that gas production in MECs can be accurately tested using an inexpensive, simple gas meter.
Keywords: hydrogen production; Microbial Electrolysis Cell (MEC); gas meter; liquid displacement method; Gas Chromatography (GC); barrier solutions; solubility test.
Microbial Fuel Cell - A Source of Renewable Energy : A Review
by Virendra Singh, Akanksha Saxena, Asha Gupta, Savitri Singh, Vidushi Kaul, Narendra Kumar
Abstract: Energy crisis in world is increasing every year due to depletion of fossil fuels as well as continued increase in the prices. There is an urgent need to identify an alternate fuel or a renewable source for energy production. Hence, microbial fuel cells (MFCs) can play a major role in producing bioelectricity using organic and biodegradable waste. The traditional MFCs consisted of anode and cathode compartments. MFCs are of two types single chambered and double chambered. Microorganisms actively use organic substrate for their metabolism, and bioelectricity generated. Apart from the bioelectricity production, MFCs has many applications like in wastewater treatment, in biosensor, in bio-hydrogen production, in bio-methane production etc. Besides the advantages of this technology, MFCs have some limitations such as low voltage, power and current density. To overcome these limitations, the different components of MFC such as electrodes and proton exchange membrane modified to explore the other possible practical options. Besides that, this research update describes the improvement and advancement of MFCs with their advantageous and futuristic application with different parameters affecting the bioelectricity production.
Keywords: Microbial fuel cells; Wastewater treatment; Electricity generation; Biohydrogen; Biosensor.
Need of Turbocharging: With Focus on Producer Gas Fueled Internal Combustion Engines A Review
by VIVEK KULKARNI, Anil T.R., Rajan NKS
Abstract: The vital need for the reduction of harmful environmental impact during energy production necessitates research for efficient, economically feasible energy developing techniques. Hence much greater emphasis is being placed on reducing the fuel consumption of engines due to global move to reduce CO2 emissions. One of them is the use of gaseous fuel, namely Producer Gas (PG), as full supplement fuel in internal combustion engines. The earlier studies on use of PG in engines for power generation have reported a de-rating in their delivered peak power. Since PG can be obtained from various biomass gasification sources, the literature also suggests a varying de-rating of 20-40% on different spark ignited engines used by different researchers. To overcome this difficulty, turbocharging is known to be a better option to recover the power loss from a given engine size. This paper emphasizes on the need of turbocharger for producer gas fueled spark ignited internal combustion engine.
Keywords: Producer Gas; Turbocharger; Spark ignited engine; Compressor; Turbine; De-rating.
Optimal Active and Reactive Power Control of Wind Turbine Driven DFIG using TLBO Algorithm and Artificial Neural Networks
by Mahmoud ElKholy, Hamed Metwally, Garib M. Regal, Mohamed Sadek
Abstract: This paper investigates the optimal active and reactive power control capabilities for typical WT driven DFIG. The main objective is to determine the optimal rotor voltage to extract certain active and reactive power from the DFIG over wide ranges of wind speed. TLBO algorithm is a new heuristic optimization technique, used to obtain the optimum rotor voltages to achieve reference active and reactive powers overall operating points. ANN controller is used as an adaptive controller to predict the value of rotor voltage for all operating points. The ideal power curve of a 2 MW wind turbine has been estimated to design the active power controller. The stator reactive power control capability with the range of
Keywords: (Doubly fed induction generator; active and reactive power control; teaching learning based optimization; artificial neural network).
Design and Optimization of Enzymatic Saccharification for Bioethanol Production from Parthenium hysterophorus Biomass using Response Surface Methodology
by Shivani Bhagwat, Anil Kumar
Abstract: The critical conditions for saccharification of polysaccharides from pre-treated biomass of Parthenium hysterophorus were carried out using response surface methodology based on Plackett-Burman and Box-Behnken design. In this study, temperature, moisture contents, pH, substrate loading, enzyme loading and incubation time were taken into consideration for optimization of the conditions before fermentation. Using Plackett-Burman design, regression was predicted to be 95.26%. The adjusted regression and predicted regression were 89.58% and 72.71%, respectively indicating coincidence. Box-Behnken design was employed to investigate optimum conditions from the factors deduced by Plackett-Burman design (PBD). The parameters taken for the second order polynomial equation analysis were temperature, pH, enzyme loading and substrate loading, where regression was predicted as 0.97. The standard deviation and coefficient of variation (CV%) were calculated to be 24.31 and 7.80%, respectively. The predicted regression and adjusted regression were 0.86 and 0.94, respectively indicating good agreement with the predicted model. It was found that 30oC temperature, pH 4.5, enzyme loading of 1.0 ml and substrate loading of 1.0 g was the optimum conditions for maximum release of fermentable sugars. 8% of substrate loading rate was maintained for the experiment. Ethanol yield was 70% of the maximum theoretical yield based on pretreated biomass after 72 h using optimum conditions.
Keywords: Biofuel; Box-Behnken design; Cellulose degradation; Enzymatic saccharification; Fermentation; Gas chromatography; Plackett-Burman Design; Saccharomyces cerevisiae; Statistical Modelling; Scanning electron microscopy.
Comparison of four methods in estimation of Weibull parameters for wind speed data of Bhopal, India
by Vaishali Sohoni, Shivcharan Gupta, Rajeshkumar Nema
Abstract: Two parameter Weibull function, is the most commonly used and accepted distribution for wind energy applications. The ability of Weibull probability distribution function to represent the wind speed data of a particular location is dependent on the method used for estimation of its parameters. This paper presents a comparison of four methods viz the graphical method, the method of moments, the energy pattern factor method and the maximum likelihood method for estimating the shape and scale parameters of Weibull function for describing wind speed data recorded in Bhopal. The performance of these methods is evaluated by the root mean square error and R square statistical indicators. The maximum likelihood method produces least error followed by the moments, energy pattern factor and graphical methods. The performance of graphical method is found to be the worst among the four methods analysed here.
Keywords: Probability distribution; Weibull function; Maximum likelihood method; Root mean square error; Kurtosis.
Comparative study of performance and emission characteristics of a CI engine using blends of corn oil methyl ester (COME) with diesel fuel
by Dinesh Kumar Sharma, Ram Kumar Agrawal
Abstract: The rapidly increasing demand of energy and depletion of fossil fuel resources lead to renewable energy developments such as vegetable oils, animal fats and their derivatives. Biodiesel derived from vegetable oils such as their methyl esters and ethyl esters are promising as performance parameters are comparable with diesel fuel and exhaust emissions are lower than that of diesel fuel. In the present work, methyl ester of corn oil is prepared by transesterification using methanol. The physical and chemical properties of corn oil methyl ester (COME) are comparable with diesel fuel. Tests have been carried out to evaluate performance and emission characteristics of a compression ignition (CI) engine using COME100 and its blends (COME25, COME50 & COME75) with diesel fuel. The acquired data are compared and analyzed under different load conditions for the diesel fuel.
Keywords: diesel engine; biodiesel; corn oil methyl ester.
Corrective load shedding using fuzzy decision tree approach for real time voltage security enhancement of power system
by Sanjiv Kumar Jain, Narayan Prasad Patidar, Yogendra Kumar
Abstract: The paper proposes a novel algorithm for optimal load shedding using fuzzy decision tree. The presented algorithm is computationally efficient and can be utilised for on-line voltage security enhancement. It is based on Fuzzy Decision Tree. To avoid the voltage collapse condition and the system status is in non-correctable emergency, the final remedy is load shedding. Due to the feature selection approach of decision trees the method is fast enough for on-line load shedding of power system. The scheme is based on the notion of the static voltage stability margin. The vigorous classification of potential samples is simple due to the advantage of decision tree. The work presents the load shedding approach for all credible line outages. Classification of voltage security is done initially using test cases after the training of decision tree (DT). Which is further tested for secure and insecure status of the power system. The result shows the fast and accurate conversion of insecure cases to secure cases for a credible contingency condition. The initial database is prepared by wide variations of loading conditions at all the load buses using traditional approach of continuation power flow method. The effectiveness of the proposed algorithm of load shedding is tested using IEEE-30 bus system. The power management system applicability of the presented methodology is quite suitable for on-line control decisions to restore the power system in secure condition after disturbances.
Keywords: Continuation power flow (CPF),Credible contingencies; Fuzzy decision tree (FDT); Optimal Load shedding; Power system security; Voltage collapse,.
Special Issue on: New and Renewable Energy Resources
Evaluation of Generation of Electricity from Wastewater Using Microbial Fuel Cell
by Kamal Ahamad, Nihal Singh, Abhijeet Das
Abstract: Microbial fuel cells (MFC) have received significant attention worldwide for its capacity to produce electricity as well as removal of waste compounds. The present work aims to evaluate the performance of MFC by varying parameters - electrode surface area and substrate. A comparison was made with the performance output of two-chamber, h-shaped unit MFC and three two chamber, h-shaped MFC connected in series. Performance of MFC were also evaluated by varying the surface area of the electrodes in both anode and cathode chamber as well as varying the substrate i.e. cooked rice, cerelac and sugar given to the anode chamber. MFCs connected in series gives better voltage output compared to single unit MFC. Electrode surface area in the anode chamber plays an important role in electricity generation. The sudden exchange of substrate from cerelac to cooked rice and vice versa does not showed any significant improvement in the performance of MFCs.
Keywords: Microbial fuel cell; Electricity; Substrate; Electrode.
APPLICATION OF ANFIS AND LIFTING WAVELET TRANSFORM FOR CLASSIFICATION OF SOLAR RADIATION
by Manju Khanna, N.K. Srinath, J.K. Mendiratta
Abstract: With increase in demand for green energy in commercial applications, need for classification of solar radiation at a site has gained importance. Present work exploits application of wavelet transform and ANFIS to classify solar radiation data, which can be exploited for optimal use of solar radiation
Keywords: wavelet transform; ANFIS; photo-voltaic; singular value decomposition; feature extraction; multi-level resolution.
Pine Needle Biomass Gasification Based Electricity and Cold Storage Systems for Rural Himalayan Region: Optimal Size & Site
by Arvind Singh Bisht, N.S. Thakur
Abstract: Pine trees cover large portions of the Himalayan region. Every summer session dry pine needles fall from the trees and cover the forest floor, which is a serious cause of uncontrolled frequent forest fires here in this region.
Due to the widespread availability of pine needles (forest biomass) in the Himalayan region, it can not only produce electricity (through gasification) for immediate local consumption and the national grid system but with the implementation of CHP and CHCP technology it can also contribute to local dairies, food processing industries and for cold storage. Using pine needles in electricity generation will not only save the environment, by preventing forest fires but also contribute to the energy demands of the region and preserve the local vegetable, fruits and milk product without any additional cost.
The objective of this study is to find out the optimal gasification system range to serve a particular locality with respect to local pine needle availability and produced refrigeration capacity.
Keywords: cold storage; optimization; gasification; Himalayan region; pine needles.
Comparative energetic and exergetic studies of vapour compression and vapour absorption refrigeration cycles
by Suman Chattopadhyay, Dibyendu Roy, Sudip Ghosh
Abstract: In this study, two types of refrigeration cycles, a vapour compression refrigeration (VCR) cycle and a vapour absorption refrigeration (VAR) cycle, have been modeled and analyzed. Both the cycles have same operating cooling loads and both operate between the same temperature limits. R134a has been considered as refrigerant for the VCR cycle whereas LiBr-H2O has been considered as the working fluid for the VAR cycle. Energetic and exergetic performances have been evaluated for both the cycles and compared. The effects of condenser temperature, evaporator temperature and environmental dead state temperature on the performances of these cycles are also discussed. Energy analysis reveals that the coefficient of performance (COP) of the VCR cycle is considerably higher than that of VAR cycle. However, exergy analysis reveals that the exergetic coefficient of performance (ECOP) of the VAR cycle is very close to that of VCR cycle. For environmental dead state temperature beyond 35oC, the exergetic performance of VAR cycle is better than that of VCR cycle. The maximum exergy destruction occurs at the evaporator for the VCR cycle but for VAR cycle, the maximum exergy destruction occurs at the generator.
Keywords: Coefficient of performance; Energy; Exergy; Refrigeration.
An Experimental Investigation of PCM based Thermal Energy Storage System using Diesel Engine Exhaust-gas
by C. U.M.A. MAHESWARI, R. MEENAKSHI REDDY
Abstract: Waste heat recovery is one of the energy conservation options. About 30% of heat produced by diesel engines that are coupled to electric power generators are carried away by exhaust gases as waste part of the heat energy produced. In the present work, CFD and experimental analysis was made to study the utilization of the waste heat energy carried by exhaust gases to obtain hot water used for various purposes in commercial buildings, hostels etc. For the heat recovery from exhaust gases, use of phase change materials (PCM) is considered and these PCMs store the energy in the form of sensible and latent heat. The main advantage of PCM is that about large quantity of thermal energy can be stored in a small volume of PCM. Experimental test was carried out using concentric cylinder type of Thermal Energy Storage System (TESS) with Stearic acid as PCM. Exhaust gases from diesel engine was made to flow inside the inner cylinder and in between the inner and outer cylinders in which PCM is filled. The effect of fins (cylindrical) arranged on the outer periphery of inner cylinder is also studied. Fin arrangement increases the heat transfer rate by reducing the charging time of TESS. Exhaust gases from a diesel engine are used as heat source to the PCM to store thermal energy in the form of sensible and latent heat. Theoretical, numerical and experimental results were compared and found that the values are closer about 10%. The performance of the TESS is evaluated by calculating performance characteristics such as charging and discharging rates of the system and 14% of heat can be recovered from the 30% energy being wasted.
Keywords: Waste Heat Recovery; Thermal Energy Storage System; Phase Change Material; Latent Heat; Concentric Cylinder.
Optimisation of energy storage for an electricity system in the Indian scenario
by MOHAMMAD ZEESHAN
Abstract: The purpose of any electrical network is to provide electrical power reliably wherever it is needed, avoiding any loss of load. To do this effectively, electricity networks usually consist of various different types of plants, giving a generation portfolio. Energy storage plays a very vital role in renewable energy generation and allows for supply and demand. The action of the energy storage should allow for a reduction of the overall system fuel cost while still meeting the load demand. The fuel cost supply curve is plotted to estimate energy storage in order to minimise the overall system fuel cost. We have used the historical data for the electricity demand from the website of Central electricity authority of India. The energy storage is optimised to minimise the overall fuel cost for the system in order to maximise profit.
Keywords: Optimiziation; Energy; Storage; Scheduling; fuel; Generation;.
CFD simulation of thermoelectric generator installed on waste heat recovery system
by Krishna Kumar Purohit, P.M. Meena
Abstract: In present research work thermoelectric generation is numerically solved for waste heat recovery based hot junction point. All experiments are designed as per DOE methodology Taguchi Method. In first part of this study, CFD simulation is performed for waste heat exchanger run on IC engine exhaust gas. Total nine cases are designed for this task using Taguchi method. Wall temperature is response variable for CFD work. In second part CFD based results are carrying forward to FEM simulation which was conduct for thermoelectric generation numerical work. Same nine cases are used for this task also. It is found that number of fins used in WHRS is not the prime factor, but mass flow rate is the main factor for this study. S/N ratio and ANOVA analysis is performed for wall temperature and current density of TEG system.
Keywords: Thermoelectric generator; CFD simulation; Taguchi Method; Linear Regression model equation; ANOVA analysis.
FAST and Simulink Based Simulation Investigation of Wind Turbine Faults
by H. Malik, S.K. Mishra
Abstract: This paper shows the application of simulations of investigation of wind turbines imbalance faults. Our proposed model of wind turbine is imitated both in normal and faulty conditions of wind turbine based on TurbSim and FAST (Fatigues, Aerodynamics, Structure and Turbulences). The imbalance fault in furl is created by changing rotor furl and/or tail furl angle (with variation of +10, +5 and -5 degree) apart from required position, which generate uneven direction of WT. Fast Fourier Transform (FFT) is applied for transforming the time-domain simulation results of whole shaft torque of the wind turbine into frequency domain. For comparing the healthy and faulty operating scenarios of wind turbine, Power Spectrum Density (PSD) plots are developed. Thereafter, energy entropy has been evaluated to compare both the conditions. Obtained results presents that created blade imbalance increases the energy level of the recorded signal. Our research work provides the online diagnosis of wind turbine faults through simulation investigation using FAST and Simulink.
Keywords: Simulink; FAST; Blade Imbalance; Imbalance Fault; Power Spectrum Density (PSD); Simulation; Wind Turbine.
Cellulase production from thermochemically pretreated Chenopodium album
by Anand Prakash, Vinay Sharma, Shivani Sharma, Arindam Kuila
Abstract: Lignocelllulosic biofuel production is the area of focus of different researchers. Cellulase mediated saccharification of delignified biomass is the rate limiting stage in biofuel generation. For enzymatic hydrolysis cellulase is key enzyme. There are several research going on for cost effective cellulose production. In the current research, Chenopodium album was subjected to dilute sodium hydroxide treatment on 120 oC. Efficiency of pretreatment was evaluated through Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and biochemical composition analysis. After pretreatment, pretreated biomass was rinsed with tap water and was subsequently kept at 70 oC for complete water removal. The biomass after complete water removal was applied for cellulase production using Fusarium oxysporum. Cellulase production was maximized using statistical technique. Within 2 days, highest cellulase production of 1.51 IU/mL was attained. The above study can be useful for efficient cellulase production for cost effective biofuel production.
Keywords: Chenopodium album; Thermochemical pretreatment; XRD; SEM; Cellulase production.
ANAEROBIC CODIGESTION OF FOOD WASTE FOR ENERGY PRODUCTION- A REVIEW
by Seema Nihalani
Abstract: Anaerobic digestion is recognized methodology for stabilizing any kind of wastewater as well as degradation of organic matter. A useful end-product of anaerobic digestion process is bio-gas. Bio-gas is fuel gas, which is a mixture consisting of methane having concentration of about 65% and Carbon dioxide having concentration of about 35%. In order to increase the yield of anaerobic digestion one of the options is carrying codigestion with several substrates. When co-substrate is used along with anaerobic decomposition process it results in positive synergism between digestion medium improves yield of biogas. Solid waste management currently focuses only on disposal options instead of harnessing or recovering energy. Therefore, by moving energy-rich food waste from landfill sites to anaerobic treatment, it can help the society to manage solid waste in a sustainable manner and also generate renewable energy. Anaerobic codigestion as a treatment option for solid waste is discussed here. Attention is laid towards anaerobic digestion using various substrates like municipal solid waste, domestic sludge, industrial sludge, animal waste, crop residues, weeds etc.
Keywords: anaerobic co-digestion; municipal solid waste,solid retention time.
A Controller model for integration of hybrid energy system into the grid
by Ibrahim Imbayah Khalefah Imbayah
Abstract: This paper introduces a controller model for the integration, of a wind system and photovoltaic system into the utility grid. The problem of integration of hybrid renewable energy based hybrid renewable energy generation system is that it relies heavily on weather conditions, PV and wind air speed. So, there is a necessity for developing control techniques for a grid integration for such hybrid system, including a method for voltage and current control that stabilizes the voltage and current. A PID control is developed in this work that is suitable for hybrid renewable energy system. Then, the system behavior and performance are studied. For different weather condition and fault condition system, stability is also considered when there are a change weather conditions in PV and air speed or a fault in the system. This paper advocate that the proposed PID controller gives a good performance. In this paper, solar energy is hybrid with wind energy. The developed MATLAB/SIMULINK design improves for integration of hybrid system performance and the results are presented.
Keywords: The hybrid renewable energy; Wind system; PV system; PID controller; the utility grid.
THERMODYNAMIC ANALYSIS OF A VAPOUR COMPRESSION REFRIGERATION SYSTEM INTEGRATED WITH A SUBCOOLER CYCLE
by RANENDRA ROY, Bijan Kumar Mandal
Abstract: In this paper numerical investigation of a vapour compression refrigeration system using mechanical subcooler loop has been presented. A mathematical model has been developed for the systems with and without subcooler based on energy and exergy equations. Refrigerant used in both the systems is R134a. The performance of the systems with and without subcooler has been analyzed and compared. The predicted results show that cooling load of the system increases nearly by 11% when subcooler cycle is employed. COP and exergetic efficiency of the system increase and exergy destruction rate decreases when subcooler is incorporated into the system. The increase in COP is found to be 11.4% and 16% at 0
Keywords: Modified VCRS; R134a; COP; Exergetic efficiency; Subcooler.
Thermodynamic Assessment of TEG-ORC Combined Cycle Powered by Solar Energy
by Sudarshan Kumar, Dibyendu Roy, Sudip Ghosh
Abstract: In this paper, a thermodynamic analysis of solar based hybrid power system consisting of thermoelectric generator (TEG) and organic Rankine Cycle (ORC) is presented. High temperature solar thermic fluid (Dowtherm A), coming from parabolic solar concentrator (PSC), is used to supply heat to the hot end of TEG as well as the heat recovery vapour generator (HRVG). The cold end of TEG acts as a preheater for downstream ORC, where heat is recovered by the ORC working fluid (R134a). In this analysis, the TEG is considered to consist of several TAGS-85/PbTe thermocouples. In the base case analysis, the TEG gives a fixed power output of 500 W and accordingly its heat supply and heat rejection rates are estimated. The system performance is assessed in terms of total power output and overall system efficiency. Engineering Equation Solver (EES) has been used for coding. The combined TEG-ORC system gives 7.5 kW of power at an overall efficiency of 9.75 % in the base case configuration when hot the TEG end temperature (HET) is 575 K and cold end temperature (CET) is 350 K. The performance parameters of the hybrid system have been analyzed for different value of hot end temperature. The important performance parameters of the combined system have been analyzed at different HET. The results indicate that the role of TEG is significant when combined system is operated at higher HET
Keywords: thermoelectric generator ; organic Rankine Cycle; parabolic solar concentrator; combined cycle.
Review of the potential of Biogas generation in India and a comparative study of various Biogas upgrading techniques
by Yunus Dalal, Rajesh Kale, Devendra Suralkar
Abstract: In India, daily human activities generate enormous quantities of biodegradable waste producing around 30 million tons of solid waste and 4400 cubic meters of liquid waste every year. The municipal solid waste (MSW) generation range is from 0.25 to 0.66 kg/person/day with an average of 0.45 kg/person /day. This easily accessible waste can be converted into energy in the form of biogas which will partially offset the dependency on the energy imports. The paper studies the potential of biogas generation in India and various biogas upgrading techniques. Various upgrading techniques have been rated based on different parameters like energy consumption, percentage removal of carbon dioxide (CO2), methane (CH4) losses, operating range of pressure and temperature, pumping system required, desulphurization and possibility of regeneration. The study suggests that selection of an upgrading technique does not depend on the tropical conditions or climate of a country but more on the application, cost investment and the process parameters.
Keywords: biodegradable waste; biogas; biogas upgrading; water scrubbing; physical absorption; chemical absorption; pressure swing adsorption; membrane separation; cryogenic separation; microalgae cultivation.
Evaluation of Optical Efficiency of an All-Glass ETC using Ray Tracing Technique
by Tarun Kumar Aseri, Chandan Sharma, Ashish Kumar Sharma, Doraj Kamal Jamuwa, Rohit Misra
Abstract: Hot water is required for various industrial process heating applications and daily domestic needs. Majority of the industrial process heating applications requires hot water in the temperature ranges of 60
Keywords: Evacuated tube collector; optical efficiency; ray tracing.
Numerical Investigation on Cooling Behaviour of Buildings using Phase Change Material (PCM)
by Ashish Kumar, SUDIP SIMLANDI, Nilkanta Barman
Abstract: As the human comfort level increases day-by-day, a demand of air conditioning is increased greatly in the world. In this context, use of phase change material (PCM) as an alternative technique towards cooling of residential and commercial buildings is a developing technology. It is one of the most economic options for saving energy, which leads to a minimum impact on the environment. Hence, cooling of buildings using a suitable PCM in a hot climate country is considered in the present work. During day time, the PCM absorbs solar radiation by melting and at night it releases the absorbed heat by solidification to the ambient. Complex transport phenomena are involved in both the melting and solidification processes. These transport phenomena are governed by mass, momentum and energy conservation equations. The set of governing equations is discretised using control volume method considering power law scheme. Finally, the SIMPLER and TDMA algorithms are used to solve the discretised linear algebraic equations. The process involves melting and solidification of PCM those are incorporated using enthalpy update scheme in the model. Both melting and solidification behaviours of PCM, also variation of room temperature during a day are predicted in the simulation. As observed, the recycling of PCM is possible for next successive days if thermal conductivity enhancer (TCE) is added in PCM. Accordingly, a TCE is considered for recycling of PCM in the present work. As predicted, for a low room temperature, a TCE fraction of 0.0025 is required to add in PCM during solidification.
Keywords: Cooling behaviour of building; Modelling; Phase change material; Recycling; Thermal conductivity enhancer.
MANAGEMENT OF PLASTIC WASTE : A STEP TOWARDS CLEAN ENVIRONMENT
by Priyanka Gupta
Abstract: Plastic pollution may be defined as the accumulation of plastic products in the environment that may affect human life as well as wildlife. Plastics waste forms a significant portion of the total municipal solid waste. Plastic is composed of various chemical elements that does not easily degrade in the natural environment even after its usage or utility period. Its properties such as durability, light weight and low cost, which makes it so useful also makes it problematic when it comes to its end of life phase. Mismanagement of plastics waste may pose environmental hazards such as it spoils beauty of the city and choke drains if littered, may cause air pollution when burnt with garbage containing plastics, interferes in waste processing facilities when garbage is mixed with plastics. Therefore plastic waste management techniques are required to manage the plastic waste in an environment friendly way and helping in the proper utilization of plastic material. The solution to tackle this problem lies in following 3R namely Reduce, Reuse and Recycle. Waste plastics can be recycled and used in several ways including construction of roads.
Keywords: Keywords : Plastic; Environment; Reuse; reduce; recycle; management.
Experimental Investigations on Solar Flat Plate Collector by changing Geometry of Fin using CFD A Review
by GANESH BADGUJAR, SACHIN NIMBULKAR, MAHESH KULKARNI
Abstract: Fins are extended surface which increase the heat transfer rate. It is most commonly used in heat exchanger device such as car radiator, Computer CPU heat sink and hydrogen fuel cell etc. Fins increase area of heat transfer in cooling and heating application. Our ultimate aim is to reduce losses present in flat plate collector by conduction, convection and re-radiation. Lots of experimentation has been done to improve the heat transfer rate of solar water heater by adding fins of helical, rectangle, circular, trapezoidal section as well as twisted shape. This paper makes summary of the all previous work on solar FPC with number of geometrical shapes of Fins and their effect on efficiency of Flat plate collector. As surface area increase heat transfer from fins also get increases. So implementation of fin in solar FPC is also most promising techniques that enhance the heat transfer rate through absorber.
Keywords: Solar FPC; Fins Geometry; Experimentation; CFD analysis; Efficiency.
Nanofluid as a coolant for next generation high heat dissipating electronic devices
by Abdul Razak Kaladgi, Faheem Akthar, Amjad Khan, Abdul Razak Buradi, Balal Hassan, Isquander Yunus, Mohammed Sami Dafedar, Mohammed Rafiq A, Farooq Indikar
Abstract: The development of integrated electronic devices with increase level of miniaturization, higher performance and output has increased the cooling requirement of chips considerably .So the use of Nanofluids to cool these electronic components is inevitable. In this work, an experimental investigation of heat transfer and pressure drop characteristics of rectangular Minichannel arrays cooled with alumina Nanofluids is carried out. The study was conducted under steady forced, turbulent flow conditions keeping heat flux as a constant and varying the flow rates. For all investigated flow rates, it was observed that with increase in Reynolds number, both the Nusselt number and pressure drop increases which further lead to increase in pumping power. The Brownian motion, interaction of nanoparticles and the resulting disturbance in the boundary layer can be the possible reasons for the observed increments.
Keywords: Rectangular Minichannel; Nanofluids; heat flux; turbulent flow;steady state;forced flow;.
Anaerobic digestion of grass-cuttings under mesophilic and regulated digester pressure
by Ishmael Matala Ramatsa
Abstract: The successful functioning and stability of an anaerobic digester depends on the interplay of several factors, each of which is very important to the success of the system as a whole. pH is central to the whole system as it dictate the survival for the bacteria. In this study the effect of digester pressure was investigated at a fixed temperature of 36oC. The digester pressure was manipulated using back pressure regulator. Grass cuttings were used as feed material to the digester. Three pressures of 2bar, 4bar and 6bar were investigated for a period of 10 days. The characteristics and methane yield achieved when digesting grass cuttings under constant digester pressure (gauge pressure) suggested that it is possible to produce biogas that has minimal amount of CO2.The highest methane compositions at 0bar, 2bar, 4bar and 6bar were 55.77, 62.2, 65.8 and 71.2% and carbon dioxide compositions were 58.85, 35.2, 32.5 and 26.2%.The amount of CO2 decreased significantly with increased pressure and the pH values dropped to 7.01, 6.96 and 6.78 respectively with increase in pressure.
Keywords: Regulated pressure; pH; ammonia-nitrogen; methane; inert gases.
Mesophilic temperature range effect on anaerobic digestion of residential grass cuttings using simple batch digester
by Ishmael Matala Ramatsa
Abstract: In the current study the main objective was to look into how the temperature and other resulting parameters impact on the stability of a biogas reactor during digestion of the residential grass cuttings in an oxygen deficient environment over a period of 10 days. During this period of digestion ammonia nitrogen was found to be below inhibitory limits. N/C ratio of the grass was found to be 20.54 and total solids about 87.88%. pH levels for temperatures close to optimum fluctuated between 6.99 and 7.2. Concentration of ammonia nitrogen recorded for all temperatures were all below inhibiting range. A high constant acetic acid concentration was recorded for 40oC, indicating that metanogenesis was stopped, causing a cessation of biogas production. This was accompanied by a low pH level. The highest daily methane compositions produced during the digestion at the temperature of 32, 34, 36 38 and 40oC were 49, 52, 56.2, 53 and 26% respectively.
Keywords: Ammonia inhibition; temperature; HOAC; methane; pH.
Comparative Performance Analysis of an SI Engine with Treated and Raw Biogas
by Amit Jhalani, Shyamlal Soni, Dilip Sharma, Pushpendra Kumar Sharma
Abstract: The study investigates the comparative performance of a single cylinder SI engine operated on treated and raw biogas. The methane content of this gas is utilized as the fuel.The biogas is treated with different methods before fuelling in the engine and hence the performance of the engine is compared. The raw biogas is treated for removal of moisture and H2S because H2S is poisonous in nature and moisture lowers the power output and may corrode engine parts. In this work, CaCl2 and silica gel were used separately for the absorption of moisture. Activated carbon and iron chips were used for the elimination of H2S. The results revealed that the increase in efficiency depends on the type of treatment given to raw biogas. Moreover, scrubbing of moisture had a greater impact as compare to the H2S removal. Effect of biogas treatment on engine emissions is also studied.
Keywords: Biogas; SI Engine; Purification of biogas; Alternative Fuel; Renewable.
Preparation and Characterization of Cao nanoparticle for biodiesel production from mixture of edible and nonedible oils
by Jharna Gupta, Madhu Agarwal, AJAY KUMAR Dalai, S.P. Chaurasia
Abstract: Calcium Nitrate (CaO/CaN) and Snail shell (CaO/SS) were successfully utilized for the development of CaO nanoparticle and used in biodiesel synthesis from a mixture of edible and nonedible oils. These solid base heterogeneous catalysts were characterized by FT-IR, XRD, and TGA techniques. DebyeScherer equation also calculated the average crystalline size of a nanometer. The comparable catalytic activity of CaO/CaN and CaO/SS catalyst was also studied for biodiesel production and found the increment of biodiesel yield from 88% to 92% using CaO/SS. The used optimum reaction conditions were: 6wt% catalyst loading, 65
Keywords: Biodiesel; snail shell; transesterification; mixture of oils.
Wavelet and Hilbert Huang Transform Based Wind Turbine Imbalance Fault Classification Model Using K-Nearest Neighbor Algorithm
by Hasmat Malik, S. Mishra
Abstract: Wind turbine (WT) is a key part in wind power generator system (WTGs). For proper operation, condition monitoring and fault diagnosis is a major part in WTGs. In this paper, three different types of nacelle yaw faults along with healthy condition are analyzed using wavelet Transform (WT) and Hilbert Huang Transformed (HHT) based k-Nearest Neighbor (k-NN) algorithm. For decomposing the raw signals, discrete approximation of Meyer wavelet function (DMeyer/ dmey) is used and to extract the feature, Hilbert Huang Transform is used to find the amplitude and phase feature of decomposed signal. k-Nearest Neighbor algorithm based classifier is designed for classifying faults based on extracted features. Prepared feature matrix of twenty one attributes is used for wind turbine nacelle yaw imbalance fault classification. Proposed technique is being compared with other computational intelligence dependent techniques of artificial neural network network (i.e. multilayer perceptron-MLP). Results and different comparisons of proposed technique could work as an essential tool for fault diagnosis of WTGs.
Keywords: dmey wavelet transform; Wind turbine; Feature extraction; Hilbert Huang transformation; k-nearest neighbor
algorithm; Fault diagnosis.
Techno-Economic Scrutiny of HRES through GA and PSO Technique
by Yashwant Sawle, S.C. Gupta, Aashish Kumar Bohre
Abstract: Presented work analyses the feasible sizing of two different hybrid renewable energy systems (HRSE) are PV-Wind-Biomass hybrid systems and PV-Wind hybrid systems. The proposed system includes battery unit for storage purpose and diesel generator for reliable operation. The electricity price or cost of energy (COE) is minimized as objective function to decide the optimal solution of hybrid system using GA and PSO. The optimal size of HRES is selected based on the lowest value of COE. The optimal solution includes high reliability, maximum value of renewable fraction, less emission and low penalty cost according to minimum COE. The maximum value of loss of power supply probability (LPSP) is assumed 2% in this case study for reliability analysis. This paper aims to present the techno-economic feasibility of above mentioned HRES for a remote area of Jamny Ven Village barwani district, India. The optimization results are evaluated through load following and cycle charging dispatch strategy furthermore the results are also compared using GA and PSO optimization techniques. Hence, the main purpose of presented work is to compare the performance results of GA & PSO with minimization of COE using load following and cycle charging dispatch strategy.
Keywords: Hybrid renewable energy system; dispatch strategies; COE; LPSP; penalty cost; pollutant emission.
Performance of Generalized Unified Power Flow Controller (GUPFC) in Transmission System
by RAJAREDDY DUVVURU, B. VENKATA PRASANTH, V. GANESH
Abstract: This manuscript focuses on innovative dynamic representation of power electronics based on generalized unified PFC (power flow controller). The GUPFC is a Voltage Source Converter (VSC) based Flexible AC Transmission System (FACTS) controller used to provide series and shunt compensation among the multi transmission line systems of a substation. GUPFC improves the performance of power quality issues, active and reactive power oscillations in multiple transmission lines. This paper proposes a complete replica comprising of 48-pulse Gate Turn-Off (GTO) thyristor based VSC which examines the dynamic operation of control scheme for shunt and two series VSC for voltage stabilization and active and reactive power compensation by using POD controller among the transmission lines of the grid network. The total digital simulation of shunt VSC which is operating as a Static Synchronous Compensator (STATCOM) and able to control the voltage at bus and two series VSC which is operating as a Static Synchronous Series Capacitor (SSSC) which is able to control injected voltage, at the same time as keeping injected voltage in quadrature with current within the power system is completely modelled in MATLAB/SIMULINK.
Keywords: 48-pulse GUPFC; Power Oscillation Damping; Power Quality.
A modeling and analysis of exhaust gas recirculation system to lower the NOx emission from internal combustion engine: a review on advanced and novel concepts
by Zulfukar Ali Ahmed, Dinesh Kumar Sharma
Abstract: Internal combustion (IC) engines emit harmful gases such as HC, CO2, and NOx etc. In terms to avoid serious effects like global warming, researchers are rigorously working towards identification of options to lower these. Search is on for better alternatives to the fossil fuels to propose clean and green fuels. Possibility of engine hardware modifications are also being tried to lower the emission of these harmful gases to environment. NOx is a very toxic gas element of this family, which is responsible for very horrible effects such as acid rain, water quality deterioration, ground level ozone, and visibility impairment.
Uses of vegetable oil as fuel, water injection, exhaust gas recirculation (EGR) and after treatment technique are the basic way to minimize the NOx emission which is too much harmful, exhausted from IC engine. EGR technique is worldwide technique to reduce the NOx emission by diluting the fresh charge with recirculation of some amount of exhaust gas, which results in lowering the maximum temperature of internal combustion engine. However, its use also reflects in terms of reduced brake thermal efficiency and more smoke emission. Study shows that proper optimization can be helpful for minimizing the emission of NOx without much effecting with the performance of Internal Combustion engine.
In the present review, modeling and analysis of different types of EGR have been reported and compared. Out of them, analytical results favor the use of long route (LR) EGR over short route (SR) EGR and hybrid EGR. Long route EGR is capable to fulfill desired outcome with practical use also by lowering the heat losses in the engine with the help of intercooler.
Keywords: exhaust gas recirculation; exhaust emission; global warming.
SOLAR SORPTION COOLING FOR RESIDENTIAL AIR-CONDITIONING APPLICATIONS
by Julia Aman, Paul Henshaw, David Ting
Abstract: This paper presents the comparison of two sorption cooling systems for providing air conditioning in a residential building that can be driven by a flat plate solar collector. A thermodynamic model has been developed for each system to compare the energy balance in each component and the coefficient of performance (COP). Analyses have been performed for 10 kW water-ammonia absorption and activated carbon-ammonia adsorption chillers. For both systems, the first law efficiencies have been compared and the optimum efficiency has been investigated under different operating conditions. Analysis revealed that under any operating condition, the COP is always higher for the absorption chiller and its maximum value is 0.6, which is almost twice that of the adsorption chiller (COP=0.35), for 10 kW systems operating at evaporator and condenser/absorber temperatures of 2oC and 30oC, respectively. The adsorption system requires a higher energy input to produce the same cooling effect as compared to the absorption system.
Keywords: air conditioning; absorption; adsorption; ammonia; activated-carbon; energy; COP.
Optimal Conditioning Monitoring of Wind Turbines Using Intelligent Image Processing and Internet of Things
by Sujatha Kesavan
Abstract: The aim is to suggest a control scheme for the wind mills which convert wind energy to electrical energy. The functioning of the governing scheme is characterized by incorporating it to a Doubly Fed Induction Generator (DFIG). The stationary part of the DFIG is unswervingly linked to the electric network. The rotating part is allied to this electric network all the way through a back-to-back AC-DC-AC PWM converter. Fuzzy logic is used to acquire features using decision making logic which as human-like flexibility. The FLC provides a crisp and smooth control action. The governing process of the converter on rotating part is comprehended by stationary magnetic flux to adjust the performance of the Fuzzy Logic Controller (FLC). The FLC is opted to have an intelligent speed control. To enable a level direct current voltage and to guarantee a pure sine wave for the current in the grid side a Grid Side Converter (GSC) is used which is controlled using FLC. The accuracy of the FLC used for the control of DFIG has a quick vibrant retort with almost unsteady error value once evaluated with the scheme using conformist Proportional Integral (PI) controller. Image processing algorithms are used to track the blade sweep and angular velocity. The entire monitoring is implemented using ATmega processor and incorporated in cloud service for online monitoring.
Keywords: Doubly Fed Induction Generator (DFIG); Fuzzy Logic Controller; Power Converters; Image processing ; Internet of Things.
A Comparative Study of Oxygenated Additives for Diesel in Compression Ignition Engine
by Chandan Kumar, K.B. Rana, B. Tripathi, Ashish Nayyar
Abstract: Performance improvement and emissions control are quite difficult to handle simultaneously in diesel engines. These two tasks can be achieved by one of the methods such as: engine design improvement, engine exhaust treatment and modification in fuel. The modification of fuel using additives is most feasible approach to control the high emissions without deteriorating the engine performance. The aim of this paper is to present the comprehensive review and comparative study of oxygenated additives with respect to engine performance and emission characteristics. It is concluded from literature review that oxygenated compounds are the most suitable and economical among all additives available for this purpose.
Keywords: C.I. engine; diesel; additive; emission; performance.
Special Issue on: Sustainable Energy Technologies
STUDIES ON HYDROGEN FUELLED STATIONARY C. I. ENGINE OPERATED END-UTILITY SYSTEM
by Vinod Singh Yadav, Dilip Sharma, S.L. Soni
Abstract: The refineries turned in a better performance with their cumulative 181 million tones crude throughput, almost 7 per cent more than the previous fiscals achievement and a little over 2 percent of the planned target. The world is presently confronted with the twin crisis of fossil fuel depletion and environmental degradation. Combined residential and commercial energy demand is expected to increase in order to meet the expected increase in electricity demand as the worlds population shall grow and more people shall move to urban areas with access to electricity. The search for an alternative fuel, which promises a pleasant link with sustainable development, energy conservation, management, efficiency, and environmental safeguarding, has become highly noticeable in the present context. rnIn this investigation, fresh air with hydrogen enrichment was used as intake charge in a C. I. engine. Experiments were conducted on a 1-C, 4-S, air-cooled, stationary direct-injection diesel engine (Kirlosker TAF1) with maximum 1500 rpm and maximum 4.4 kW capacity coupled to an electrical generator. The injection timing (17
Keywords: Hydrogen-Enrichment; Injection timing; Flow rate of hydrogen; Performance.