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An Experimental Analysis in a DICI Engine Powered with MWCNT Blended Emulsions
Abstract
Owing to the current crisis of environmental degradation generated from various sectors, many efforts have been tried out to commensurate the ecological cycle of the earth. The main contributors causing the environmental degradation are the industrial, transportation, and power plant sectors. Diesel engines are mostly used as a prime mover in those sectors to generate power owing to their superior thermal efficiency. However, at the same time, they also give off deleterious pollutants (like smoke, oxides of nitrogen, unburnt hydrocarbons, etc.). In order to reduce those deleterious pollutants, the present research study is focused to amend the diesel fuel properties on mixing the multi-walled carbon nanotubes (MWCNTs) as fuel-borne additives along with ordinary water methodically. Ordinary water (in prefixed volume percentage, say 2% and 4%) in presence of MWCNT and surfactants was employed to prepare the MWCNT unified water-diesel emulsions methodically and eventually tested for stability. The MWCNT blended water-diesel emulsions were examined in a CI engine to assess the working feature traits. It was established that MWCNT+ water mixture with the diesel, the emissions, and performance traits of the CI engine were ameliorated. It was noted that due to the existence of MWCNT in the water-in-diesel fuels, the secondary atomization effects could have influenced during the combustion period, and thereby caused the reduction in the magnitude of emissions (oxides of nitrogen, unburnt hydrocarbons, and smoke in particular).KeywordsMWCNTEmulsionStabilityPerformanceEmissionsDiesel engine
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An Experimental investigation was carried out to find out combustion performance and emissions characteristics of diesel engine using nano-aluminum oxide (n-Al2O3) mixed diesel. The n-Al2O3 of size 50 nm was mixed into diesel fuel at the rate of 0.5g/l and 1g/l for formulation of new alternate fuels. The n-Al2O3 was dispersed by means of an ultrasonic sonificator in order to produce uniform dispersion of n-Al2O3 in the diesel fuel. Nano-Al2O3 possesses better combustion characteristics and enhanced surface-area-to-volume ratio and hence allows more amount of diesel to react with the oxygen which in turn enhances the burning efficiency of the test fuels. This also enhanced using neodymium magnets which separates the molecules of the clustered hydrocarbon. The magnets are fitted across the fuel line to give best magnetic field for the fuel to flow through. The diesel fuel with and without n-Al2O3 additive were tested in a variable compression diesel engine at different load conditions and the results revealed that a considerable amount of enhancement in the brake thermal efficiency and substantial reduction in content of NOx and unburnt hydrocarbon (UBHC) at all the loads compared to neat diesel were observed due to nano Al2O3’s better combustion characteristics and improved degree of mixing with air.
A numerical investigation on the prediction of temperature, major species (CH 4, CO 2, CO, H 2 O, N 2, O 2) from methane/air partially premixed flames are obtained for different primary equivalence ratios (ф). A computational model for an axi-symmetric partially premixed flame has been developed. Standard k-ɛ model is used to simulate the turbulent quantities. Different species transport equations are solved for different species followed by Fick's law. In order to predict the soot, Brookes and Moss soot model has been incorporated along with modified model constants through a developed precursor correlation. Discrete ordinate (DO) radiation model is employed to include the radiation effect throughout the flow field. The governing equations are solved by using ANSYS Fluent 14.0. The pressure based steady solver has been used to solve 2-D geometry in Cartesian coordinate system. When the equivalence ratio increases, the flame height observed to increase. The exact flame height is ascertained from the axial distributions of temperature and different species. The soot in the flame of equivalence ratio ф=1.48 is negligibly small and distributed in a very small area along the axis. The formation of soot in the flames is higher with increase in equivalence ratio.
This paper theoretically characterizes the sloshing phenomena at the free liquid surface in partially or filled stationary containers based on the analogy with surface gravity waves. The oscillations of the liquid surface and the associated dynamics of the liquid-air interface results in interfacial wave displacement of two types progressive (in-phase) and standing (out of phase) modes. This study involves a rectangular stationary fluid tank partially filled with the tested fluids and subjected to the dominant progressive wave at the liquid-air interface. The sloshing strength is decided based on the temporal progression of the generated wave spectrum obtained utilizing small-amplitude wave theory and linear stability analysis in combination. The expressions for determining the angular frequency, the phase speed, and the corresponding temporal growth rate of the progressive disturbances is derived. The tested fluids include standard liquid water and commercially preferable fluids ethylene glycol and glycerol. This model developed based on the irrotationality of fluid motion neglects the viscous influence and comprises the gravity and the surface tension mimicking a practical scenario. Utilizing deep-water assumptions, the effect of surface tension has been determined for wavenumbers in the range of 490-1250 rad/m. The independent evolution demonstrates the influence of surface tension on the temporal growth rate. Water with the maximum surface tension has a higher growth rate than a low surface tension fluid ethylene glycol among the tested fluids. The effect of surface tension is to escalate the temporal growth rate leading to instability and increased liquid sloshing rate.
This work consider the use of PFAD oil for the production of renewable and environment friendly biodiesel fuel as an alternative to conventional diesel. Test quantities of PFAD oil biodiesel were produced through transesterification reaction, 20% methanol (vol% PFAD oil), 0.8% (wt%) potassium hydroxide catalyst at 60oC reaction temperature and 90 min reaction time. The PFAD oil biodiesel produced was subsequently blended with petroleum diesel and characterized as alternative diesel fuel through ASTM standard fuel test. Variable Compression Ratio (VCR) engine test rig was used to determine the effect of compression Ratio (CR) on the performance and emission characteristics of the test fuel. Test were carried out at compression ratios of 16:1, 17:1, and 18:1 at different load. The performance parameters like Brake Thermal Efficiency (BTE), Brake Specific Fuel Consumption (BSFC) and Exhaust gas temperature (EGT) were studied. At higher compression ratio the increase in BTE is observed for PFAD20 blend when compared to diesel. BSFC of biodiesel blend is higher at all compression ratios due to lower heating value of the fuel. However the biodiesel exhibited lower emission at CR 18 compared to neat diesel except NOx. The NOx is increased due to higher compression and better combustion characteristics of the biodiesel blend. Thus B20 blend at CR18 can be effectively used in diesel engine with better performance and reduced emissions.
Carbon nanotube-based (CNT-based) interfacial evaporation material is one of the most potential materials for solar desalination. Here, we studied the evaporation rate of the CNT-based membranes with different hydrophilic and hydrophobic chemical modified surfaces using molecular dynamic simulations. We found that the hydrogen bonding density among water molecules at the interface is a key factor in enhancing the evaporation rate. For a hydrophilic CNT-based membrane, the strong interactions between the membrane outer surface and the water molecules can destroy the water-water hydrogen bonding interactions at the interface, resulting in the reduction of the hydrogen bonding density, leading to an enhancement effect in evaporation rate. We also found that there is an optimal thickness for evaporation membrane. These findings could provide some theoretical guidance for designing and exploring advanced CNT-based systems with more beneficial performance in water desalination.
Absorption technology becomes an attractive option for cooling or heating when driven by solar thermal energy, residual heat from different processes, or geothermal energy. Further development of this technology could help to cover current cooling or heating requirements and have a much lower impact on the environment than mechanical compression cooling and heat pumps systems. Moreover, the rising cost of electrical energy added to the issue of climate change are reasons to move towards the development of environmental and sustainable energy technologies. The desorbers are key components of absorption heat pump technologies. Studies in the open literature on desorbers show advances in new design concepts to enhance heat and mass transfer with different working fluids. Therefore, the objective of this review is to identify, summarise, and discuss the experimental studies that deal with the boiling process in desorbers and boiling correlations specifically for use in absorption heat pump technologies. It includes a comprehensive scrutiny on the boiling phenomenon in pool desorbers, falling-film desorbers, and forced flow desorbers for conventional and promising working fluids, and details the experimental techniques and the latest advances in desorber design concepts. Finally, the review contains proposals for future studies to be carried out so as to contribute to the further development of absorption heat pump technologies.
Currently, the use of fossil fuels is very high and existing nature reserves are rapidly depleted. Therefore, researchers are turning their attention to find renewable fuels that have a low impact on the environment, to replace these fossil fuels. Biogas is a low-cost alternative, sustainable, renewable fuel existing worldwide. It can be produced by decomposition of vegetation or waste products of human and animal biological activity. This process is performed by microorganisms (such as methanogens and sulfate-reducing bacteria) by anaerobic digestion. Biogas can serve as a basis for heat and electricity production used for domestic heating and cooking. It can be also used to feed internal combustion engines, gas turbines, fuel cells, or cogeneration systems. In this paper, a comprehensive literature study regarding the laminar burning velocity of biogas-containing mixtures is presented. This study aims to characterize the use of biogas as IC (internal combustion) engine fuel, and to develop efficient safety recommendations and to predict and reduce the risk of fires and accidental explosions caused by biogas.
With the invention of petroleum in 1859, R & D of internal combustion (IC) engine powered vehicle commenced and the first gasoline powered automobiles hit the market of Germany in 1876. Two major problems are associated with petroleum powered automobiles; these are chemical and noise pollution. These are causing tremendous damage to the nature and its habitat. Also the petroleum reserve is fast depleting. Hence all the eyes were focused towards non-petroleum bases automobile. Automobile with alternate fuels, engine with improved efficiency were tried but keeping the health of our planet in mind, maximum thrust of research is aim to run the automobile using green energy. Solar energy, the most popular green energy, found suitable in light transport like rickshaw and three wheelers because of low energy density. EV may be the solution of future transportation system. It offers zero emission and reduces noise pollution. Cost of purchase of EV is more, though its less running cost. The technology, especially the energy storing technology is yet to be matured. Overall cost of EV will come down within affordability with the technology. EV will be popular over conventional vehicle and it appears to be the viable solution in near future.
In the pursuit to improve thermal and fuel efficiencies of internal combustion engines, various engine designs and configurations have been developed over recent years. Since the progress in this field keeps on increasing continuously, the geometrical aspects of combustion chamber and the engine configurations and their effects on the in-cylinder air/fuel mixing, turbulence and fuel combustion are becoming more relevant than ever. Due to this, there lies an impending need for a critical analysis of current in-cylinder flow analysis techniques available, their application on different engine types and the results acquired from the studies. Several new flow measurement technologies have emerged and for the past ten years, a critical analysis of airflow capturing methods within IC engines has not been done despite its great significance. This review presents a short yet a meaningful understanding to the analysis techniques for engine in-cylinder flows during the intake and compression of air and fuel, while bringing out significant findings from individual works, resulting in pointing out the strengths and accuracies of these techniques. In the reflection of reviewed studies, explicit analytical schemes and formulations bearing least errors compared to experimental results, are suggested.
Electric vehicle (EV) penetration has been increasing globally and is expected to continue its exponential growth over the coming decades. Several countries have already announced plans to achieve total or partial electrification of their vehicle fleets. Such rapid transportation electrification will have a significant impact on society and businesses that support the transportation industry. Additionally, new business opportunities will be available to support this technological evolution. In this paper, the business opportunities emerging from EVs and their supporting infrastructure are reviewed. It has been observed that several businesses, such as sustainable mining and manufacturing, will need to be developed before EV growth as they provide the initial platform required for EV adoption. Other businesses such as fleet optimization, battery management, and recycling can be developed at a later stage. All of these businesses will also have social and technological impacts, which will drive policy decisions. Regional governments play a critical role in ensuring the smooth execution of a transition to transportation electrification through social programs, such as training and education for equitable growth, and legislative decisions, such as technology standardization.
The performance of porous media micro-burners plays an important role in determining thermal efficiency and improving our daily life. Nowadays, a lot of scholars are actively involved in this research area and ongoing studies are still being carried out due to the burners' excellent performance. The exergy efficiency and entropy generation of a porous media burner are strongly dependent on the characteristics of the flame and its thermal behavior. In this study, a single-layer and double-layer porous media form were constructed to investigate the effects of various types of porous foam arrangement in a cylindrical burner. The burner was operated using premixed butane-air combustion with an inner diameter of 23 mm and a length of 100 mm. The experiments were carried out in rich fuel conditions with an equivalence ratio, φ ranging from 1.3 to 2.0. The results showed significant improvement in the thermal and exergy efficiency with an increase in the equivalence ratio in a double-layer compared with a single-layer. The peak temperature recorded was 945.21 °C at φ = 1.3 for a porcelain single-layer, and the highest exergy efficiency was 83.47% at φ = 2.0 for an alumina-porcelain double-layer burner. It was also found that the average temperature of the burner wall decreased with an increase in the equivalence ratios for PMB2 and PMB4, whereas the average wall temperature for PMB3 was largely unaffected by the equivalence ratios. The total entropy generation rate reached the highest value at φ = 2.0 for all PMB configurations, and the highest percentage increase for total entropy generation rate was 46.09% for PMB1. The exergy efficiency for all burners was approximately similar with the highest exergy efficiency achieved by PMB4 (17.65%). In addition, the length and location of the flame with thermal distribution was significantly affected by the equivalence ratio between the single-layer and double-layer porous material. Overall, a double-layer porous media burner showed the best performance calculated based on the second law of thermodynamics when compared with other configurations, and it is ideal for domestic application.
The main drawback of reluctance machines is a high torque ripple, due to the interaction between the stator magneto-motive force and the rotor structure. Adopting a rotor configuration characterized by several flux barriers per pole, there is a high influence of the rotor geometry on the machine performance, in terms of both average torque and ripple. An optimization is often required to determine the optimal rotor geometry so as to achieve a high and smooth torque. Then, the geometry determined above should guarantee good performance for various operating points (i.e., changing the current amplitude and phase), as well as for small variations of the geometry. This paper investigates this aspect, showing the results of optimizations carried out on various machines. The impact of the geometry parameters is taken into account and the sensitivity of the optimal solution to the geometry variation is pointed out. The paper highlights the difficulty to get a robust geometry as far as the torque ripple reduction is concerned. Finally, a few experimental results on a Synchronous Reluctance motor prototype will be presented, compared with Finite Element Analysis simulations for validation.
Floods remain one of the disasters that destroy properties, livelihoods, and in extreme situations, take lives. As a way of prevention, geospatial applications have been employed in many cities to map flood zones and predict floods. For a country such as Ghana, floods have been ranked as the second fatal disaster after epidemics leading to several kinds of research to resolve them. To date, the Cape Coast Metropolis (CCM) has received little attention in terms of research, though flood cases in the area continue to escalate. This study, therefore, examines the use of geospatial techniques as tools in addressing flood problems in the CCM of Ghana. From a Digital Elevation Model, hydrologic variables were generated using the ArcGIS software (Esri, Redlands, CA, USA). The soil drainage classification for the study was generated from a downloaded African Soil Grid Drainage map, while other important factors that influenced flooding in the CCM were obtained from Landsat 8 imagery. Over 21% of the CCM was classified as high flood hazard zones with areas around the river Kakum estuary being flood hotspots. It is, therefore, recommended that the CCM Assembly fund dredging of streams/rivers and promote afforestation along river banks to reduce the risk of flooding within the metropolis.
This paper presents a generalized space vector pulse width modulation SVPWM for the switched capacitor voltage boost converter. The algorithm is based on relaxing the location of the ON time interval within the sampling time. The four switching functions of the SC converter result in four variable that represent the location of the ON time inverter. The optimal solution of the four variable is obtained by using Monte Carlo simulation that is based on minimizing the harmonic distortion factor. Furthermore, the proposed algorithm allows seamless transition between the various SVPWM such as DPWMMAX, DPWMMIN, and regularly sampled SVPWM. The finding of this paper is presented in a form of MATLAB simulation results.
Petroleum based fuels are the main source of energy for the transportation vehicles. It is consumed in a very faster rate due to continuous use. Major drawback of fossil fuel usage is exhaust gas emission and it is non-renewable. The search for alternate energy source has been increasing; one of the better alternatives is biodiesel. The biodiesel can be effectively used as an alternate fuel instead of diesel as its properties is very close to diesel. The biodiesel extracted from Karanja oil is tested in diesel engine as B100 and B20 blend and its results were compared with diesel. It was found that the brake thermal efficiency is low for biodiesel and its blend compared to diesel. The specific fuel consumption increases for B100 and B20 than diesel due to its reduced heating value. Carbon monoxide and hydrocarbon emission is reduced considerably for B100 compared to B20 and neat diesel. At the same time the NOx emission is also observed to be decreasing for B100 and the NOx of B20 is closer to diesel. From the results obtained the Karanja oil biodiesel can be directly used in direct injection diesel engines and can be a better alternate fuel for the conventional one.
Biodiesel is one of the better replacement for diesel fuel because of the depleting fuel resources. The cost of the biodiesel compared to diesel is major setback in commercialization. As mass production is encouraged the cost involved in production will reduce and may available at the cost less than diesel. Biodiesel is one of the promising source of fuel which stands as one of the better alternative diesel fuel. This study represents the production of biodiesel by using esterification and transesterification of pongamia oil which is obtained from pongamia pinnata. Diethyl ether and zinc oxide used as additive to enhance cetane number, properties of biodiesel. The DI diesel engine is tested for its Performance and emission characteristics using pure biodiesel, biodiesel with 5%DEE biodiesel with 50ppm of zinc oxide, diesel on four stroke direct injection diesel engine were studied. And found that biodiesel with 5%DEE gives better result than biodiesel. Biodiesel with added additives gives 5% higher brake thermal efficiency than diesel at full load condition, hydrocarbon emission less than 10%, carbon monoxide emission 40.35% less than B100, NOx is 0.7%, hydrocarbon 11.36% were lower than biodiesel. Thus, pongamia biodiesel with 5%diethyl ether can be used as one of the alternative source of energy for diesel.
A rapid increase in the use of non-biodegradable plastics and their disposal after use has had a detrimental impact on the environment. Used plastics (used low-density polyethylene – ULDP) were selected as feedstock for the extraction of pyrolytic oil. The pyrolysis process was carried out in a semi-batch reactor with a silica alumina catalyst in the existence of fluidizing gas N2 in a reactor at 500 °C for 60 min. The maximum liquid, gas, and char yields were 93.5 wt%, 5.4 wt%, and 1.1 wt%, respectively. Experimental analysis was carried out to obtain their functional and structural groups by FT-IR and the carbon distribution was identified by GC-MS analysis. The blends of 20%, 40%, 60%, 80%, and 100% on a volume basis were chosen for the detailed study. For the pyrolytic blends, the combustion, performance, and emission characteristics were tested at different engine loads. During combustion, the heat release rate was extremely high for neat ULDP oil because of the high energy content and a higher cetane index. The efficiency of ULDP20 was higher than in other blends, whereas NOx and smoke emissions of ULDP20 were lower among the blends but higher than diesel. ULDP20 performed similarly as diesel. Hence, ULDP20 is recommended as a fuel for the diesel engine.
This paper introduces a new topology of multilevel inverter, which is able to operate at high performance. This proposed circuit achieves requirements of reduced number of switches, gate-drive circuits, and high design flexibility. In most cases fifteen-level inverters need at least twelve switches. The proposed topology has only ten switches. The inverter has a quasi-sine output voltage, which is formed by level generator and polarity changer to produce the desired voltage and current waveforms. The detailed operation of the proposed inverter is explained. The theoretical analysis and design procedure are given. Simulation results are presented to confirm the analytical approach of the proposed circuit. A 15-level and 31-level multilevel inverters were designed and tested at 50 Hz.
The main objective of this study is to lower the greenhouse gases by developing and optimizing a solar flat plate collector. The rifled tube is integrated into the collector to increase the thermal heat transfer thereby improving its performance. Two flat plate collectors, one with in-housed longitudinal fins and another without fins of 0.5 m2 collector area, have been intended and fabricated with provisions for K-type thermocouples to examine the temperature variations inside the collector for different working fluids. This current study reveals using CuO and Al2O3 nanoparticles in varying weight fractions in incremental order to study the effect of weight fractions on the efficiency of the collector. The simulation was done using computational fluid dynamics both for the finned and without finned tube collectors separately and the outcome of the results for the collector outlet temperatures is compared with the experimental one and results show a valuable outcome for the intended collectors. Initially, the test was conducted with pure distilled water as working fluid and further nanoparticles were opted and doped inside the collector side for varying weight fractions of 0.2% and 0.4% and their results are compared. The experimental results showed an improved heat transfer was pragmatic in the collector side for using nanoparticles. Mixing the nanofluids exhibited superior efficiency on the collector side. The results showed after successful trials of experimentation, doping of CuO nanoparticles by varying weight fractions of 0.2% and 0.4%, augmentation of the collector (unfinned) efficiency is 2.1% and 4.05%, and similarly for finned tube collector, it is 3.02% and 5.5% for same weight fractions. In order to improve the thermal efficiency of collector, CuO is replaced by Al2O3 nanoparticles; for dissimilar weight fractions, the efficiency is enhanced nearly by 3.7% and 6.54% for unfinned tube collector, and for the finned tube, the collector is 4.8% and 7.8% respectively, compared with the base working fluid (water). Experimentation of the collectors with finned tube type achieved a superior efficiency compared with that of unfinned tube collectors which is proved to be higher when used for nanofluids to that of the base working fluid water.
Selective solar absorber thin films of copper oxide (CuO) on copper substrates were synthesised through chemical oxidation using alkaline solution and additives at 60 °C for different oxidation reaction. The surface morphology, elemental composition, structural and optical properties of the CuO coatings were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and UV–VIS-NIR Spectroscopy and emissometer respectively. From XRD peaks cupric oxide (CuO) phases were confirmed from all the films. EDS spectrum confirms that all the synthesized nanocoatings is mainly Cu & O, which was free from contamination. Nanoflake-like structure and nano-pillar like surface are observed from SEM and AFM morphology, respectively. The surface roughness of the CuO films was ranged from 13.8 to 15.7 nm. The solar absorptance (α) and thermal emittance (ε) of the CuO nanostructured thin films were ranged between 91.84 and 89.06%, and 9–13%, respectively. A high solar absorptance of 0.92 and low thermal emittance of 0.13 was achieved for 2.0 hr oxidation time.
Currently, our global environment has been affected due to the air pollution caused by many sectors (such as automotive, industrial, transportation) in higher magnitudes. Many environmentalists, scientists, researchers and engineers have contributed their efforts to eradicate the air pollution. It is well known noted that most of the harmful pollutants were evolved from diesel engine power engines/plants. Considering the objective of enhancing performance and reducing harmful emissions of diesel engine, the current research work has been conducted on mixing DEE (Di-Ethyl Ether) and normal water with normal diesel fuel in definite quantities. Five stages of investigations were carried out to perform the task of blending water and DEE with the normal diesel fuel. In the first stage, to obtain the baseline readings, normal diesel fuel was experimented in a light duty constant speed diesel engine. Normal water (2% & 4% by vol.) was combined with the normal diesel fuel with the aid of emulsifiers (Span80 & Tween80) and mechanical stirrer (speed of 3000 rpm) to obtain the water blended diesel emulsion fuels in the second stage. In the third stage, DEE was mixed with water-emulsion fuels which were prepared in the second stage. The stability and properties of fuels was determined in the fourth stage. In the fifth stage, the prepared stable DEE-water-diesel emulsion fuels were tested in a light duty constant speed diesel engine generator and eventually compared to those readings of normal diesel fuel. Experimental outcome from all the tested fuels revealed that water and DEE mixed emulsion fuels reflected better performance and reduced harmful emission attributes.
The electrical vehicles selling increase in last few years due to availability of charging facility. The charging station located on highways defines public EV charging station plays an important role to fast charge of electrical vehicles. In this paper, grid-tied PV and energy storage unit base charging station design by considering different modes of operation. The MPPT base boost converter is used to extract maximum power from the PV. The charging–discharging of energy storage battery design by the buck-boost converter. Five EVs battery parameters are considered to calculate real-time EV load. For the uninterrupted charging of EVs, whenever PV and energy storage power are not available or the available power does not meet load demand throughout the day, the deficient power is taken from the grid. The optimal energy flow between PV, ESU, grid, and EVs is obtained by a PI-based current control strategy. The different operating modes of power flow among sources and EV load are designed, and the same is formulated and validated in MATLAB/Simulink.KeywordsRES Base EV C.SEnergy management of EV C.SPV-ESU C.S
This paper explores the significance, most recent developments, and innovative challenges in the implementation of Electric Vehicle chargers along with the energy storage systems and analyses its impacts on EV. Throughout the years, various studies and papers have been published on EV charging for both stand-alone and grid powered EV systems. With the developing enthusiasm for this theme, it is convenient to have a detailed review, to sum up and update all the related studies in EV battery charging, and to introduce it as a solitary reference. A total evaluation of charging power levels and framework for EVs followed by the correlation of unidirectional, bidirectional chargers are introduced remembering the current status and issues in EV.
Industrial waste heat recovery shows significant potential for increasing energy efficiency in industry. However, to design strategies that exploit this potential, it is necessary to have data about the quantity and characteristics of industrial waste heat flows. This information is not always readily available and many companies do not even have a systematic record of these energy flows. Hence, bottom-up methodologies to estimate that recovery potential by means of key transfer figures are useful tools within this field. In the present article, four different methods are applied to determine the industrial waste heat recovery potential in the Autonomous Community of the Basque Country (northern Spain), an energy-intensive industrial region with large energy dependency from the outside.
Besides, the analysis of the economic viability of the industrial waste heat recovery is essential, because it determines the final adoption of energy efficiency measures. For that aim, the authors develop an easy-to-apply bottom-up methodology to carry out an assessment for the economic potential of the estimated industrial waste heat at different temperature levels. This method is applied to 129 companies, whose potentials are characterized and discussed.
The obtained results show that, for waste heat streams above 400°C, more than 90% of the studied companies present payback periods below five years. For those industries with waste heat temperatures below 200°C, the ratio decreases to around 40%, still a noticeable value. The estimations show a significant opportunity to implement solutions to recover this wasted energy, especially in the iron and steel sector and the petrochemical industry. The development of public policies that encourage these measurements would be also beneficial.
India’s energy requirement is growing up with its economic growth. The increase in energy consumption is a sign of increasing prosperity of a nation. The large requirement of energy is fulfilled by non-renewable source of energy, which is a fast depleting source and causes heavy pollution in the environment. With the rising concern for the environment because of the change in climate conditions have forced developing nations to opt for alternate source of energy other than non-renewable sources. The best alternate is provided by the clean and renewable sources of energy such as solar, wind, biomass, small hydropower and waste to wealth. Because of the favourable environment condition, India has the great potential for clean and renewable sources of energy. India’s geographical condition gives it a leverage in the generation of wind, solar and biomass energy, and with the increasing urbanisation and industrialization, rise in solid waste gives it a great potential for the generation of energy from waste. This paper discusses over the different sources of clean and renewable energy available in India and the potential of these sources to fulfil the energy need of the nation in future for a sustainable economic growth. The different policies and programmes that are adopted by the government for the promotion of clean and renewable source of energy and the various obstacles that are faced for the further growth of this sector.
In this study, six different three-way catalysts were tested based on the engine bench to investigate the effect of platinum group metal (PGM) loadings and ratios of the catalysts on the transient emission characteristics of a heavy-duty natural gas engine. From the results of this study, NOx are the most important emissions to be considered when optimizing catalyst parameters. PGM ratio can significantly affect the total emissions and change the distribution of peak emissions, while PGM loading showed small impact on total emissions and no effect on peak emissions distribution. The main contribution of higher PGM loading and better PGM ratio were the faster light-off of the after-treatment system and the reduction of peak emissions. With decrease of Rh content and Pt/Pd ratio, NOx, HC, and CO emissions all increased, while NH3 concentration decreased. Pt is indispensable in formula and TWC without Pt content exceeded the regulation limit. For NH3, the average concentration increased in cold-start cycle and decreased in hot-start cycle when PGM loading increased. Slightly reduce the Rh content and increase the Pt/Pd ratio is a feasible route to reduce the cost of the TWC as well as maintain a high efficiency. The findings of this paper provide scientific references to balance cost and performance of TWC on natural gas engine, while achieving engine clean emissions.
In the present examination, the effect of Aluminum oxide suspended in water at concentration of 0.03% as nanomaterial for turbulent flow using multiple twisted tapes (TTn) in a solar flat plate collector was scrutinized. Properties are estimated by utilizing previous correlations. Outputs are described for a different number of turbulator and Reynolds number (Re). The increase in Sgen,f (1604.672) is more significant for higher Re = 20,000. The highest Sgen,th (15,788.13) is observed for TTn = 1 and Re = 4000. The highest number of Be is 0.9987 when the TTn = 1 and Re = 4000. Both the Be number and the Фs shows the same trend for the reported results. The increase in the number of Re and TTn reduces the values of Be and Фs. Output results verify that the use of turbulators enhances the nanofluid flow resulting in enhanced heat transfer, which also provides higher flow disturbance. Therefore, it can be concluded that using twisted tapes and nanofluids can result in reduces exergy losses.
Propane, n-butane and their mixtures are commonly used as fuels for various appli-
cations. Reliable numerical simulations of flames involving these fuels are most
essential to study their efficient use in domestic and industrial burners. Such sim-
ulations require a suitable reaction mechanism containing the necessary kinetics to predict key combustion characteristics in flames accurately. However, the use of detailed kinetic mechanisms for these computations is formidable in multidimensional simulations, owing to their large sizes. To address this, in this work, a compact mechanism (45 species, 392 reactions) for propane, n- butane, and their mixtures, suitable for multi-dimensional simulations is derived and comprehensively validated against available experimental data in flames. The main oxidation pathways retained in this compact model are showcased. One-dimensional computations of premixed and non-premixed flames are carried out using FlameMaster and Chemkin-Pro. Two-dimensional calculations are performed within ANSYS-FLUENT. Here, multi-component diffusion, thermal diffusion and radiation sub-models are used.
Laminar flame speeds, extinction strain rates, and amounts of major species in pre-
mixed flat flames are validated using 1D computations. Temperature and major species in propane and n-butane jet diffusion flames are verified in 2D simulations.
Further, 2D computations using the compact mechanism also predicts the laminar burning velocity of premixed flames of n-butane and propane mixtures established over a Bunsen burner. The ability of the compact mechanism to predict desired targets in premixed and non-premixed flames is analysed from a kinetic basis. Validation using 2D simulations demonstrates the usability of the compact mechanism in multi-dimensional computations.
The industrial sector accounts for more than 54% of the total energy produced in the world with a predicted annual growth of 1.2%. Currently, most of the industrial sectors use fossil fuels to meet their heat energy requirements and it can be replaced by renewable energy resources particularly solar energy. In this article, an extensive review of various solar thermal energy technologies and their industrial applications are presented. The following industries are covered: power generation, oil and gas, pulp & paper, textile, food processing & beverage, pharmaceutical, leather, automotive, and metal industries. For each of the applications, quality and quantity of heat requirements are identified. Though all the applications are consuming heat in the form of steam/hot water, power plant and enhanced oil recovery have huge potential for solar steam augmentation as compared to other applications. Similarly, applications such as petroleum refining, pulp & paper, and rice mill require a huge amount of steam/hot water. The process heat requirements for textile, food & beverage, pharmaceutical, leather, and automotive industries are at a lower temperature. The integration of solar thermal energy systems with the industrial processes mainly depends on the local solar radiation, availability of land, conventional fuel prices, quality of steam required, and flexibility of system integration with the existing process. Furthermore, challenges involved in the integration of solar thermal energy systems with the process heat industries are explored along with the economics. The future outlook has been proposed to overcome the challenges involved in the integration.
The coconut fatty acid distillate (CFAD) was used as a novel feedstock for biodiesel production in this investigation. Its characterization as fuel in diesel engine was also studied. A maximum biodiesel yield of 92.6% was obtained, when esterification is performed with 10:1 methanol to oil ratio, 2.5% sulphuric acid at 60 °C for 90 min. This is followed by transesterification with optimized parameters of methanol to oil ratio 8:1, 1.5% potassium hydroxide at 60 °C for 90 min. 20%, 40%, 60% and 100% of CFAD biodiesel (CFAB) was added to diesel to form blends CFAB20, CFAB40, CFAB60 and CFAB100. Engine test results showed that the performance of CFAB20 is closer to diesel than the other CFAB blends. The brake thermal efficiency (BTE) of CFAB20 was found to be 4.7% lesser than diesel. Nitrogen oxide emission is higher for all biodiesel blends due to enhanced combustion characteristics. However, carbon monoxide, hydrocarbon and smoke were reduced by 50%, 36.6% and 42.9% respectively for CFAB100 when compared to diesel at full load. Thus it is inferred that the CFAD is a potential source for biodiesel production. CFAB20 can be used in diesel engines with acceptable BTE and reduced emissions without any engine modification.
As a result of increased global emission, higher fuel price, and limited natural resources, the need of alternative fuels is highly focused by various researchers. Use of edible oil in internal combustion (IC) engine is finding its place to replace the use of conventional fuel. In the present experimental investigation, corn oil methyl ester (COME) and its blends of biodiesel fueled in diesel engine to assess the combustion, performance, emission characteristics. The maximum blend ratio of corn oil methyl ester is limited to 30% with neat diesel. Results showed that using B10 biodiesel blend significantly improved the performance of engine and the maximum engine efficiency using B10 biodiesel blend is found as 33.98% and it is lower than neat diesel. Similarly, the BSFC of diesel engine using B10 biodiesel blend is increased only by 2%, whereas, using B20 and B30, the brake specific fuel consumption (BSFC) increased to about 4 and 6%, respectively. Results showed that the formation of NOx is higher as the oxygen content available in the fuel is higher and similarly, the CO2 during combustion increased. The other emission such as CO and HC are reduced.
This experimental study, blended jatropha biodiesel and higher alcohol (butanol) were employed in an unmodified diesel engine and its effects on exhaust emissions were studied. The jatropha biodiesel produced from jatropha oil by transesterification process. The evaluated test fuels were diesel (D100), jatropha biodiesel (BD100), 90% of biodiesel and 10% of butanol blend (B90A10), 80% of biodiesel and 20% of butanol blend (B80A20), and 70% of biodiesel and 30% of butanol blend (B70A30). The experimental results were compared with diesel fuel. Results show that the addition of butanol, enhancing emission characteristics owing to its inherent oxygen content. A significant reduction in all emissions was found when adding butanol in biodiesel at all engine loads. Overall, the butanol blending in jatropha biodiesel can be potential alternative fuel owing to its better emission characteristics.
The Biodiesel is an alternative fuel which can be produced from various feedstocks like vegetable oils, seeds, animal fats and animal tallow. In-case of oil it will be extracted from the seeds with the help of an expelling process. Chemical expelling is efficient method to extract oil from the seeds when compared to mechanical expelling. Due to lower production cost mechanical expelling will be used in most of the cases. This oil consists of FFA content, Based on FFA content single step/two step transterification process will be followed. In this Linseed oil the FFA content is 1.87, hence single step transterification process is followed. The triglyceride esters will be converted into the Mono-glyceride by a catalyzed reaction. The reaction conditions generally involve a trade-off between reaction time and temperature as reaction completeness is the most critical fuel quality parameter. Much of the process complexity originates from contaminants in the feedstock, such as water and free fatty acids, or impurities in the final product, such as methanol, free glycerol, and soap. Processes have been developed to produce biodiesel from high free fatty acid feedstocks, such as recycled restaurant grease, animal fats, and soap stock. This linseed seed has been tested with FTIR analysis, GC-MS analysis and physical properties. All the properties are satisfying the ASTM standards. The physical properties of the linseed biodiesel has been incorporated.
Liquefied Petroleum Gas (LPG) is a fossil fuel mixture, widely used in domestic and industrial burners for several applications. Non-premixed flames are commonly preferred in these burners owing to their stability and controllability. However, based on operating conditions, non-premixed flames emit emissions such as CO and soot. Several techniques, including supply of coflow air and partial premixing of air with fuel, are used to abate these emissions. Due to multicomponent nature of LPG and its complex oxidation pathway, numerical studies on LPG flames are scarce in literature. However, such studies are helpful in the analysis of flames in several burners. With this motivation, systematic numerical simulations of canonical non-premixed coflow flames of LPG and air, without and with partial premixing of air in the fuel stream, have been presented. A two-dimensional axisymmetric domain is used to represent coflow burner. The numerical model includes sub-models to account for soot formation and its oxidation, and radiation energy loss due to participating species and soot. A short kinetic mechanism with 43 species and 392 elementary reactions is used. Results from the numerical model have been validated for flames of propane, n-butane and LPG. Coflow air is varied as proportions of stoichiometric air. Partial premixing of air to the fuel stream results in a reactant mixture that is not flammable. Characteristics of flames in all these cases are presented systematically using the fields of temperature, flow and species mass fractions. A relative comparison of soot production between all these cases is made. Results reveal that in coflow flames, the net soot emissions increase initially, reach a local maximum and then decrease. In partially premixed flames, soot emissions continuously decrease with an increase in the primary air and become almost negligible after a specified air addition to the fuel stream.
Experiments were conducted to determine the engine performance and emission characteristics of Direct Injection (DI)—diesel engine using aqueous cerium oxide nanoparticles (ACONP) and aqueous aluminium oxide nanoparticles (AAONP) as an additive in diesel, ethanol and surfactant blended fuel and were compared with diesel fuel. Blends were prepared by in proportions of Diesel 83%, Ethanol 15% and Surfactant 2% (Span 80) with 50 and 75 ppm aqueous cerium oxide and aqueous aluminium oxide nanoparticles as an additive, denoted as ACONP50, ACONP75, AAONP50 and AAONP75, respectively. The blends are prepared by uniform mixing of nanoparticles with the help of an ultrasonicator. Nanoparticles were acted as an oxygen-donating catalyst which improves the combustion process and results in complete combustion. This will also reduce the hydrocarbons (HC) and carbon monoxide (CO) emissions. It was observed that there is a significant enhancement of performances and decrease of exhaust emissions HC, CO, smoke, slight increase in nitrogen oxides (NOX) as compared to diesel fuel. The combustion parameters like cylinder pressure and heat release rates are increased for both nanoparticles as an additive which has been compared with pure diesel.
Industry is one of the leading energy consumers with a global share of 37%. Fossil fuels are used to meet more then 80% of this demand. The sun's heat can be exploited in most industrial processes to replace fossil fuels. Integration of a thermal energy storage system is a requisite for sustainability in solar heat for industries. Currently there are only 741 solar heat industrial plants operating with an overall collector area of 662,648 m 2 (567 MW th) that cover very small share of total global capacity. This is only the tip of the iceberg-there is a huge potential that is eager to be exploited. The challenges of increasing cost-effective solar heat applications are development of thermal energy storage systems and materials that can deliver this energy at feasible economic value. Sensible thermal energy storage, which is the oldest and most developed, has recently gained interest due to demand for increased sustainability in energy use. This paper attempts to review these latest trends in sensible thermal energy storage systems and materials that are used in solar industrial applications with a special focus on sustainability. The aim is to provide information for further research and development that shall make solar heat a cost-effective method to meet the increasing energy demand of the industrial sector.
In this paper, the performance of a gas/oil heat recovery unit is assessed experimentally and by the development of an Aspen model and artificial neural networks. The heat recovery unit is a cross-flow heat exchanger used to recover the residual heat of the exhaust gases coming from a microturbine to drive an absorption chiller. The test facility consists mainly of a microturbine, a heat recovery unit, and an air-cooled absorption chiller. The experiments were conducted at partial power loads and different thermal oil mass flows. Regarding the models, the Aspen model depends on inlet conditions, the mechanical description of the heat recovery unit, and the fluids thermophysical properties, whereas the ANN model consists of 3 trained artificial neurons, 4 inputs (inlet flows and temperatures), and 2 outputs (thermal load and overall heat transfer coefficient). The experimental tests show that the recovery unit recovers from 18.8 kW to 8.1 kW when the microturbine power output is varied from 23 kWe to 4 kWe. Results also show that the overall heat transfer coefficient ranges between 243 W.m−2.K−1 and 89 W.m−2.K−1, while they evidence that the overall heat transfer resistance is controlled by the exhaust gases heat transfer resistance. Furthermore, simulation results show that the Aspen model predicts the heat recovery unit thermal load and overall heat transfer coefficient with average relative differences of 0.93% and 11.27%, respectively, to the experiments. The ANN model evidences average relative differences of 0.51% and 3.48% for the thermal load and overall heat transfer coefficient, respectively.
Present study investigate the emission pattern of compression ignition engine using Jatropha (J100), Deconal blends with jatropha (JB90D10, JB80D20) and compared with conventional Diesel (D100). Emission parameters such as hydrocarbon (HC), Carbon Monoxide (CO), Nitrogen Oxides (NOx) was measured using gas analyser at various load conditions. Without any additives deconal can be directly added with biodiesel. Engine is quiet smooth in operation and no damage is found in engine parts. Jatropha biodiesel results lower level of carbon monoxide and hydrocarbon with increase in NOx emission. Appending Deconal blends with JB100 shows reduction compared with diesel at all loads.
Solar energy as a plentiful and environment-friendly source of energy has an acceptable potential in nearly most of the regions around the world. Thermal technologies are commonly used to provide heat requirements of different domestic, agricultural, residential, and industrial applications from the sun. This paper reviews thermal performance enhancement techniques of the most widely-used low-temperature solar collectors (LTSCs) including flat-plate collectors (FPCs), evacuated tube collectors (ETCs), and compound parabolic concentrators (CPCs) by introducing challenges and discussing future research potentials. In this regard, energy analysis of each collector type along with the latest advancements to boost the heat collection capability of the LTSCs reported in the previous studies is presented. The discussed methods in this study broadly cover structural modifications, absorber coatings, integration with reflectors, using alternative working fluids including nanofluids, and employing thermal energy storage (TES) systems. This comprehensive review is reflecting the level of technical maturity of each type of LTSCs and is expected to serve scientists, engineers, and developers with the latest achievements in this technology.
Small Pacific islands are highly dependent on diesel fuel imports to run diesel generators for their electricity needs. Diesel generators are less than 40% efficient and at least 60% of energy is wasted in the form of heat. A significant share of the electricity is consumed for running electric reefer containers that are employed by islanders for the conservation of imported food. This study investigates the feasibility of constructing a Cooling Service Centre (CSC) to host the reefer containers of a small island, utilising the recovered heat from the exhaust of the diesel generators of the island’s power plant, and using Nauru as a case study. Two scenarios are considered: in the first, a cool-store hosting the reefer containers is maintained at a predetermined temperature. In the second, fixed porthole reefer containers are stacked in an open area next to the power plant. In both scenarios, absorption chillers are employed to convert the recovered heat from the generator exhausts and provide cooling. The remainder of the recovered heat is utilised for heating the inlet water of three reverse osmosis (RO) desalination units to increase the flow rate of permeate (fresh water) production. The results show that the most economically feasible scenario is a cool-store held at -20°C, with a pay-back period of 10 years. In a business model where users of the CSC facilities pay for cooling space, the required monthly service charge per reefer container has a maximum of AU$556 for the lowest considered diesel price. This compares favourably with the current monthly electricity cost of AU$1350 that users pay to keep each reefer container running. Such a reduction in the expenses of business owners would make, at least, around a AU$440,000 annual saving in the costs of preservation of imported food and a significant reduction in its market price. Also, the annual water production of desalination units increases by 81 million litres, thus significantly alleviating potential water shortages. Besides, an annual reduction of around 1.1 kilotonnes in total carbon emission is expected to be achieved.
Liquid desiccant dehumidification system driven by heat pump is recognized as an efficient approach for humidity control in the air-conditioning system. The liquid desiccant dehumidification system is optimized by exergy destruction analysis method in the present research. According to the exergy destruction theory, the exergy destruction of a liquid desiccant dehumidification system is divided into exergy destructions arising from heat pump cycle, evaporators, condensers, heat and mass transfer modules and various mixing processes, respectively. The heat and mass transfer process uniformity coefficients γt and γω are proposed to describe the uniformity of the heat and mass transfer driving forces along the whole system. It's indicated γt and γω of the basic cross-flow system are as high as 1.4 and 1.2. Then reducing the exergy destruction is chosen as the guideline to optimize the system. On the basis of the basic cross-flow system, the improved cross-flow system and the improved counter-flow system are further proposed. γt (γω) of the improved systems are reduced to 1.12(1.12) and 1.04(1.01), respectively. Owing to the system optimization, the exergy efficiency increases from 20.1% of the basic cross-flow system to 21% and 25% respectively, COPsys increases from 5.7 to 6.0 and 7.4 respectively. The exergy analysis method is effective for an optimized scenario of a heat-pump driven liquid desiccant process.