| 1. |
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| 2. |
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| 3. |
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| 4. |
- Arya, N., et al.
(författare)
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Porosity-Engineered CNT-MoS2 Hybrid Nanostructures for Bipolar Supercapacitor Applications
- 2023
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society. - 1944-8244 .- 1944-8252. ; 15:29, s. 34818-34828
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Tidskriftsartikel (refereegranskat)abstract
- Bipolar supercapacitors that can store many fold higher capacitance in negative voltage compared to positive voltage are of great importance if they can be engineered for practical applications. The electrode material encompassing high surface area, better electrochemical stability, high conductivity, moderate distribution of pore size, and their interaction with suitable electrolytes is imperative to enable bipolar supercapacitor performance. Apropos of the aforementioned aspects, the intent of this work is to ascertain the effect of ionic properties of different electrolytes on the electrochemical properties and performance of a porous CNT-MoS2 hybrid microstructure toward bipolar supercapacitor applications. The electrochemical assessment reveals that the CNT-MoS2 hybrid electrode exhibited a two- to threefold higher areal capacitance value of 122.3 mF cm-2 at 100 μA cm-2 in 1 M aqueous Na2SO4 and 42.13 mF cm-2 at 0.30 mA cm-2 in PVA-Na2SO4 gel electrolyte in the negative potential window in comparison to the positive potential window. The CNT-MoS2 hybrid demonstrates a splendid Coulombic efficiency of ∼102.5% and outstanding stability with capacitance retention showing a change from 100% to ∼180% over 7000 repeated charging-discharging cycles. © 2023 American Chemical Society.
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| 5. |
- Attri, Shubham Dutt, et al.
(författare)
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Multi-attribute sustainability assessment of wastewater treatment technologies using combined fuzzy multi-criteria decision-making techniques
- 2022
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 357
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Tidskriftsartikel (refereegranskat)abstract
- Water, which is predicted to be one of the most critical resources for the near future, also plays a vital role in society's sustainable development. Wastewater treatment is a critical part of the circular water management system and offers various technological alternatives. Taking appropriate decision for the technology selection is, therefore, essential for a long-term perspective. A complex yet imperative process is the sustainable selection of the wastewater treatment process. This paper presents the use of multi-criteria decision-making (MCDM) in the sustainability assessment of wastewater treatment technologies that may be very relevant to the growing sector with many emerging options. A comparison of six wastewater treatment technologies based on four sustainability parameters using three MCDM techniques, namely FSWARA, FMOORA and FTOPSIS is presented in detail. FSWARA is used for weighting criteria and the other two for technology ranking. The detailed step-by-step comparison study is presented and the results were somewhat predictable for the study, and this confirms the reliability of the methodology. This paper's primary objective is to propose a well-defined increscent practice for making sustainable wastewater treatment decisions among state-of-the-art technologies.
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| 6. |
- Barthwal, M., et al.
(författare)
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Effect of Nanomaterial Inclusion in Phase Change Materials for Improving the Thermal Performance of Heat Storage : A Review
- 2021
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Ingår i: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 4:8, s. 7462-7480
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Tidskriftsartikel (refereegranskat)abstract
- Dispersion of nanoparticles is one of the potential solutions to improve the thermophysical properties of phase change (or transition) materials (PCMs) and enhance the performance of latent thermal energy storage (LTES) systems. The PCM ought to have a high latent heat of fusion, and zero or negligible coefficient of thermal expansion. A good PCM should have melting and solidification compatibility with negligible or zero subcooling, and it should not react with the common chemical reagents. The present known PCMs possess low thermal conductivity that results into a longer solidification and melting time of PCMs. In the past two decades, researchers have reported improved thermal conductivity and heat-storing capacity of PCMs employing graphite nanoparticles/fibers, carbon nanotubes/fibers, metal, and metal oxide nanoparticles. This work reviews the reported experimental and numerical studies describing the consequences of nanoparticle inclusions of various shapes and sizes on the thermal properties of the PCMs. This review attempts to make a consolidated database of the studies related to nanoadditive inclusion into PCMs for various applications. Graphene dispersed into PCM has resulted into 14 times thermal conductivity enhancement. As far as metal oxide nanoparticles are concerned, TiO2 and Al2O3 nanoparticles outperformed others. The compatibility between the nanoadditive and PCM is necessary to tailor favorable thermal properties. This work reviews numerous studies of different nanoparticle-PCM duos. © 2021 American Chemical Society.
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| 7. |
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| 8. |
- Bonthu, D., et al.
(författare)
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3D printed functionally graded foams response under transverse load
- 2023
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Ingår i: Results in Materials. - : Elsevier B.V.. - 2590-048X. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- The applications of 3D printing are rapidly increasing in aerospace and naval applications. Nonetheless, 3D printing (3DP) of graded foams exhibiting property variation along the thickness direction is yet to be explored. In the current work, the different volume fractions of hollow glass micro balloon (GMB) reinforced high-density polyethylene (HDPE) composite based graded foams are 3D printed using the fused deposition modelling (FDM) technique. The bonding between successive layers and porosity distribution of these graded configurations are studied using micro-CT scan. Further, the 3D Printed functionally graded foams (FGFs) are tested for flexural response, and results are compared with numerical values. The micro-CT results showed delamination absence between the layers. In neat HDPE layers, porosity is not evident, while minor porosity creeps in the layers having the highest GMB content. Experimental results of the flexural test showed that the graded sandwiches exhibited better strength than the graded core alone. Compared to neat HDPE, the modulus of FGF-2 (H20–H40–H60) increased by 33.83%, implying better mechanical stiffness. Among all the FGFs, FGF-2 exhibited a better specific modulus. A comparative study of experimental and numerical results showed a slight deviation due to neglecting the induced porosity. © 2023 The Authors
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| 9. |
- Choudhary, D., et al.
(författare)
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Recycling of waste toner derived from exhausted printer cartridges as adsorbent for defluoridation of water
- 2024
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Ingår i: Environmental Technology & Innovation. - : Elsevier. - 2352-1864. ; 34
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Tidskriftsartikel (refereegranskat)abstract
- Due to the broad adoption of electronic and electrical equipment and the quick advancement of contemporary innovations in this domain, significant amounts of electronic waste have been produced. This category of waste includes the toner powder used by printers, copiers, and fax machines to print text and images. This paper describes a sustainable and environmentally friendly method of recycling waste toner powder. The chemical composition of this printer cartridge toner (PCt) powder is carbon, Fe3O4, polypropylene (polymeric resin), and SiO2 composite. Toner powder from exhausted printer cartridges was utilized as an adsorbent to remove fluoride from water. It has a fluoride adsorption capacity of 60 mg/g and a specific surface area of 20 m2/g. X-ray diffraction and electron microscopic investigations were used to investigate the chemical composition, structure, and surface morphology of the material. To analyze the collected experimental data, the Freundlich and Langmuir adsorption isotherm models were used. Time-dependent kinetic experiments were conducted to determine the mechanism of the adsorption process using pseudo-first-order kinetics, pseudo-second-order kinetics, and intraparticle diffusion kinetic models. The fluoride adsorption process was shown to be feasible and spontaneous (ΔG < 0) based on calculated thermodynamic characteristics, which included enthalpy, Gibbs free energy, entropy (ΔS > 0), and adsorption activation energy. The study also discussed its reusability as an adsorbent and examined its functioning capability in actual water. © 2024 The Authors
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| 11. |
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| 12. |
- Duryodhana, D., et al.
(författare)
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Buckling and free vibrations behaviour through differential quadrature method for foamed composites
- 2023
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Ingår i: Results in Engineering (RINENG). - : Elsevier BV. - 2590-1230. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- The current work focuses on predicting the buckling and free vibration frequencies (fn) of cenosphere reinforced epoxy based syntactic foam beam under varying loads. Critical buckling loads (Ncr) and fn are predicted using the differential quadrature method (DQM). Ncr and fn have been calculated for beams of varying cenosphere volume fractions subjected to axial load under clamped-clamped (CC), clamped-simply (CS), simply-simply (SS), and clamped-free (CF) boundary conditions (BC′s). Upon increasing the cenosphere volume fraction, Ncr and fn of syntactic foam composites increases. These numerical outcomes are compared with the theoretical values evaluated through the Euler-Bernoulli hypothesis and further compared with experimental outcomes. Results are observed to be in precise agreement. The results of the DQM numerical analysis are given out for the different BC′s, aspect ratios, cenosphere volume fractions, and varying loads. It is perceived that depending on the BC′s, the type of axial varying loads and aspect ratios has a substantial effect on the Ncr and fn behaviour of the syntactic foam beams. A comparative study of the obtained results showed that the beam subjected to parabolic load under CC boundary conditions exhibited a higher buckling load. © 2023 The Authors
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| 13. |
- Kajal, Priyanka, et al.
(författare)
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Costing Analysis of Scalable Carbon-Based Perovskite Modules Using Bottom Up Technique
- 2022
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Ingår i: Global Challenges. - : Wiley. - 2056-6646. ; 6:2
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, perovskite solar cells (PSCs) have achieved a remarkable power conversion efficiency of 25.5%, indicating that they are a promising alternative to dominant Si photovoltaic (PV) technology. This technology is expected to solve the world's energy demand with minimal investment and very low CO2 emissions. The market has shown a lot of interest in PSCs technology. A technoeconomic analysis is a useful tool for tracking manufacturing costs and forecasting whether technology will eventually achieve market-driven prices. A technoeconomic analysis of a 100 MW carbon-based perovskite solar module (CPSM) factory located in India is presented in this paper. Two CPSMs architectures-high-temperature processed CPSMs (Module A) and low-temperature processed CPSM's (Module B)-are expected to offer minimum sustainable prices (MSPs) of $ 0.21 W-1 and $ 0.15 W-1. On the basis of MSP, the levelized cost of energy (LCOE) is calculated to be 3.40 (sic) kWh(-1) for module A and 3.02 (sic) kWh(-1) for module B, with a 10-year module lifetime assumption. The same modules with a 25-year lifespan have LCOEs of 1.66 and 1.47 (sic) kWh(-1), respectively. These estimates are comparable to market dominant crystalline silicon solar modules, and they are also favorable for utilizing perovskite solar cell technology.
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| 14. |
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| 15. |
- Kaundal, Ankur, et al.
(författare)
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Numerical investigation of the effect of air supply on cook stove performance.
- 2021
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Ingår i: Inhalation Toxicology. - : Informa UK Limited. - 0895-8378 .- 1091-7691. ; 33:5, s. 193-203
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: In a domestic biomass cook stove, the air supply plays a significant role in improving the overall combustion characteristics. The present research aims to numerically investigate the effect of air supply, division of air intake into primary and secondary air, and its optimization. > In a domestic biomass cook stove, the air supply plays a significant role in improving the overall combustion characteristics. The present research aims to numerically investigate the effect of air supply, division of air intake into primary and secondary air, and its optimization. Methods: The geometries of cook stove combustion chamber were prepared and simulated using species transport model with eddy-dissipation turbulent mixing. The stoichiometric amount of air was split into different ratios varying from 50:50 to 10:90 and simulations were carried out for each case. The computational model was validated and the concentration of CO2, H2O, O2, wood volatile and resultant temperature were compared and analyzed. Results: Species transport in the form of conservation of mass along with momentum conservation and energy conservation gave the spatial distribution of resultant species and spatial temperature distribution. The computational domain with feedstock inlet corresponding to the pyrolysis regime has yielded good results compared to that in the front. In this domain, the primary to secondary air ratio of 50:50 showed the best results due to the dominance of primary air utilization and, thus, less secondary air use even at higher elevations. With the maximum temperature near 1300 K, maximum relative CO2 production, and maximum feedstock utilization, the primary to secondary air ratio of 50:50 observed to be optimum. Conclusions: Due to the adequate intermixing of reactant species and uniform diffusion of product species along the combustion chamber's height, the computational domain with feedstock inlet corresponding to the pyrolysis regime has shown realistic conditions. The temperature profile and mole fraction of various species, thus obtained, can be used to design an efficient cook stove as the cross-section and dimensions of the combustion chamber and chimney relates to approach the desired division of air.
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| 16. |
- Kaundal, S., et al.
(författare)
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Solar-Assisted Gasification Based Cook Stoves
- 2018. - 1
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Ingår i: Coal and Biomass Gasification. - Singapore : Springer. - 9789811073342 - 9789811073359 ; , s. 403-422
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Bokkapitel (refereegranskat)
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| 17. |
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| 18. |
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| 19. |
- Kumar, S., et al.
(författare)
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Buckling behavior of non-uniformly heated 3D printed plain and functionally graded nanocomposites
- 2023
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Ingår i: Polymer Composites. - : John Wiley & Sons. - 0272-8397 .- 1548-0569. ; 44, s. 5450-5463
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Tidskriftsartikel (refereegranskat)abstract
- The functionalized multi-walled carbon nanotubes (MWCNTs) (0.5–5 wt.%) are compounded with high density polyethylene (HDPE), and, subsequently, used for extruding nanocomposite filaments to fabricate nanocomposites (NCs) and functionally graded nanocomposites (FGNCs) through 3D printing. The 3D printed NCs are investigated for coefficient of thermal expansion (CTE), and buckling under different non-uniform temperature distributions (case-1: left edge heating, case-2: centre heating, and case-3: left and right edge heating). A significant reduction in CTE is observed with MWCNT addition and gradation. The highest reduction in CTE is observed for H5 (5 wt.% of MWCNT in HDPE) NC and H1 ⟶ H3 ⟶ H5 (FGNC-2) among the NCs and the FGNCs. It is noted that Tcr (critical buckling temperature) is highest for case-3 and lowest for case-2. The highest deflection is noticed in case-2, while no significant difference is observed in case-1 and case-3 heating conditions. It is also observed that Tcr increases with gradation and MWCNTs addition. The H5 NC and FGNC-2 exhibited the highest Tcr among the NCs and FGNCs, respectively. The maximum deflection is noticed for HDPE, whereas the minimum deflection is noticed for FGNC-2 and H-5 NC among the tested samples. The results also revealed that Tcr is very sensitive to type of heating. © 2023 Society of Plastics Engineers.
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| 20. |
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| 21. |
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| 22. |
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| 23. |
- Mishra, A., et al.
(författare)
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Solar Thermal Powered Bakery Oven
- 2019. - 1
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Ingår i: Advances in Solar Energy Research. - Singapore : Springer. - 9789811333019 - 9789811333026 ; , s. 577-592
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Bokkapitel (refereegranskat)
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| 24. |
- Neelam, R., et al.
(författare)
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Mechanical response of additively manufactured foam : A machine learning approach
- 2022
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Ingår i: Results in Engineering (RINENG). - : Elsevier BV. - 2590-1230. ; 16
-
Tidskriftsartikel (refereegranskat)abstract
- This paper uses ensemble and automated machine learning algorithms to predict the mechanical properties (tensile and flexural strength) of a three-dimensionally printed (3DP) foamed structure. The closed cell foams were made from the most commonly used thermoplastic, High-Density Polyethylene (HDPE). The hollow glass microspheres are infused in HDPE at varying volume %. The available data on these foams' mechanical properties are used by the chosen machine learning (ML) algorithms to propose the best suited algorithm for such a three-phased microstructure as these closed cell foams exhibit. Finally, the strength predictions from the models were validated using experimental data. The models were trained with nozzle temperature, bed temperature, and force values as input parameters. The output parameters predicted were the tensile and flexural strength. LightGBM outperforms all other models in terms of performance among ensemble-based models, while H2OAutoML outperforms all other models. All the ML algorithms produced models with greater than 95% accuracy. Finally, memory and time consumption for each model are presented. © 2022 The Authors
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| 25. |
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| 26. |
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| 27. |
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| 28. |
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| 29. |
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| 30. |
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| 31. |
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| 32. |
- Powar, Satvasheel, et al.
(författare)
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Space Heating fins
- 2021
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Patent (populärvet., debatt m.m.)
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| 33. |
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| 34. |
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| 35. |
- Saini, Prashant, et al.
(författare)
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A review of the techno-economic potential and environmental impact analysis through life cycle assessment of parabolic trough collector towards the contribution of sustainable energy.
- 2023
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Ingår i: Heliyon. - 2405-8440. ; 9:7
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Tidskriftsartikel (refereegranskat)abstract
- Parabolic trough collectors (P.T.Cs) are efficient solar energy harvesting devices utilized in various industries, for instance, space heating, solar cooling, solar drying, pasteurization, sterilization, electricity generation, process heat, solar cooking, and many other applications. However, their usage is limited as the high capital and operating costs; according to the International Renewable Energy Agency's 2020 report, the global weighted average levelized cost of electricity (L.C.O.E) for P.T.Cs was 0.185 $/kWh in 2018. This work analyses the economic, technical, and environmental potential of sustainable energy to increase the use of P.T.Cs in different sectors. To study how self-weight, heat loss, and wind velocity affect P.T.C performance, prototype testing, and wind flow analysis were used. Although P.T.Cs outperform in capacity factor, gross-to-net conversion, and annual energy production, improving their overall efficiency is crucial in reducing total energy production costs. Wire coils, discs, and twisted tape-type inserts can enhance their performance by increasing turbulence and heat transfer area. Improving the system's overall efficiency by enhancing the functioning and operation of individual components will also help decrease total energy production costs. The aim is to minimize the L.C.O.E associated with a P.T.C in order to enhance its economic viability for an extended period. When the nanofluid-oriented P.T.C was included in the conventional P.T.C workings, there was a decrease in the L.C.O.E by 1%. Of all the technologies available, ocean, geothermal, and C.S.P parabolic trough plants generate lower amounts of waste and harmful gases, with average emissions of 2.39%, 2.23%, and 2.16%, respectively, throughout their lifespan. For solar-only and non-hybrid thermal energy storage plants, the range of greenhouse gas emissions is between 20 and 34 kgCO2 equivalents per megawatt-hour. Coal, natural gas steam turbines, nuclear power plants, bioenergy, solar PV, geothermal, concentrated solar power, hydropower reservoir, hydropower river, ocean, and wind power plants all release greenhouse gases at rates of 1022, 587.5, 110.5, 633, 111, 48, 41, 82.5, 7.5, 12.5, and 41.5 gCO2-e/kWh, respectively. This information is useful to compare the environmental effect of various energy sources and help us to choose cleaner, more sustainable options for the production of electricity. The ongoing advancements and future scope of P.T.Cs could potentially make them more economically viable for domestic, commercial, and industrial applications.
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| 36. |
- Saini, P., et al.
(författare)
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Cesaro fins parametric optimization for enhancement in the solidification performance of a latent heat storage system with combined fins, foam, and nanoparticle
- 2023
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Ingår i: Energy Reports. - 2352-4847. ; 9, s. 5670-5687
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Tidskriftsartikel (refereegranskat)abstract
- The use of Phase Change Materials (PCMs) for latent thermal energy storage enhances the availability of solar energy. PCMs can store a large amount of energy in a small volume using almost entirely isothermal processes. Despite this, the poor thermal conductivity of PCMs is a significant disadvantage of current PCMs, severely limiting their energy storage capabilities. As a result, the solidification/melting rates are reduced to an unacceptable level, and the system reaction time is increased unreasonably. By combining the novel fin arrangement, nanoparticles, and metal foam, the current study improved the solidification rate of the PCM in the Latent Heat Thermal Energy Storage System (LHTESS). LHTESS was numerically evaluated in ANSYS Fluent 18.1 using a solidification and melting model. The addition of cesaro fins, nanoparticles, and metal foam significantly improved PCM solidification in the LHTESS. PCM solidification time was reduced by 42.42% and 39.39% in Type-3 and Type-5 fin configurations, respectively, when compared to Type-4 fin configuration. Furthermore, a temperature difference of 27 K between the Heat Thermal Fluid (HTF) and the PCM ensures the best solidification performance. By incorporating nanoparticles into PCM and metal foam, the solidification time is reduced by 73.68%. Depending on the foam structure and volume fraction of the nanoparticles, dispersing nanoparticles in PCM with metal foam saves up to 75% of the time. © 2023 The Author(s)
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| 37. |
- Saini, Prashant, et al.
(författare)
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Effect of the X-grid static mixer flow inserts on the performance of parabolic trough collector
- 2024
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Ingår i: International Journal of Thermofluids. - : Elsevier. - 2666-2027. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- Solar energy is a very convenient and reliable renewable energy source to fulfill our society's wide variety of energy requirements. Solar concentrator-based energy technologies are the best way to utilize solar energy nowadays. Among those technologies, PTC (Parabolic Trough Collector) is a well-mature and reliable concentrating solar power technology having various real-world applications with solar standalone as well as in hybrid modes. For improving the performance of PTC, flow inserts are a very promising technique. This work aims to investigate the X-grid static mixer flow inserts on the performance of the PTC module. Here, X-grid static mixer flow inserts are modeled and compared with the simple cylindrical tube without any inserts inside by using a validated model in Ansys Fluent 18.1. Evaluation criteria include flow analysis, overall efficiency, exergy efficiency and thermal efficiency. The overall efficiency and exergy efficiency are the most prominent factors for the evaluation of PTC performance. The PTC is analyzed with various inlet fluid temperatures ranging from 303 K to 653 K with a variation in the volumetric flow rate ranging from 50 LPM (Litre Per Minute) to 250 LPM. The enhancement in the thermal performance of PTC using an X-grid static mixer is more as the inlet fluid temperature increases. The pressure drop increases multiple times with the use of X-grid flow inserts, but the overall rise of pump work is low. Overall thermal efficiency is higher for the X-grid static mixer than the plain tube which is mainly used in the PTC. The presented investigation results can be helpful for the design of X-grid static mixer.
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| 38. |
- Saini, P., et al.
(författare)
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Experimental and numerical investigation of a hybrid solar thermal-electric powered cooking oven
- 2023
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Ingår i: Energy. - : Elsevier Ltd. - 0360-5442 .- 1873-6785. ; 280
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Tidskriftsartikel (refereegranskat)abstract
- The rapid development in technology and changing food habits have drastically altered the cooking method in recent years. Electric ovens are dominating the cooking sector in bakeries, restaurants, and domestic cooking. India holds the second position in terms of revenue generated by the sales of cookers and ovens. The electrical energy requirements are also adding up with electricity-based cooking. In addition, solar energy-dependent solar cooking appliances are available in the market, but they come with their own set of merits and demerits. This paper discusses the new concept and development of an Electric-Solar hybrid cooking appliance. The implemented control mechanism in the fully-featured hybrid OTG (Oven, Toaster, & Griller) oven shows the simplicity and ease of using solar energy in conjunction with electrical energy. The experimental and numerical results show that the temperature distribution inside an electric-solar hybrid oven saves energy up to 51% and takes much less cooking time than electric ovens and solar cooking appliances when operating in hybrid mode. The STEPCO (Solar Thermal-Electric Powered Cooking Oven) oven has demonstrated potential for a relatively quick return on investment, with a payback period of around 2.3 years in hybrid mode and 3.7 years in solar mode. Experimental testing has shown that the hybrid mode of the STEPCO oven achieves an impressive efficiency of 63%, which is significantly higher than that of the electric and solar modes, which are only 35% and 4.0%, respectively. Additionally, the STEPCO oven has the environmental benefit of emitting very little CO2 during the cooking process when used in hybrid mode and zero CO2 emissions when used in solar mode. © 2023
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| 39. |
- Saini, Prashant, et al.
(författare)
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Parametric optimization of a cesaro fins employed latent heat storage system for melting performance enhancement
- 2022
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Ingår i: Journal of Energy Storage. - : Elsevier BV. - 2352-152X .- 2352-1538. ; 51
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Tidskriftsartikel (refereegranskat)abstract
- The large-scale use of sustainable energy necessitates the use of latent heat storage (LHS). This study aims to increase the melting performance of an LHS system by designing and optimizing the cesaro fins. To examine the melting behaviours of PCM (i.e., RT-82) in a finned LHS system, a 2-D melting heat transfer model is developed and numerically solved. As per literature, there is very literature including the NC (Natural Convection) and represents the coordination in fins, nanoparticles and metal foam. So, the impacts of natural convection, fin arrangement, nanoparticles and metal foam are explored for the Fourier number variations from 0.014 to 0.158 at a constant Stefan number of 0.20. The dynamic temperature distribution, as well as the natural convection and fin arrangement, are investigated to determine how phase change material melts over time by considering the non-thermal equilibrium between metal foam and PCM/nanoPCM. The findings illustrate that natural convection has a significant effect on melting behaviours in the LHTES (Latent Heat Thermal Energy Storage) system, with a 26.8% increase in melting/charging rate as compared to the situation without NC. The LHTES system with improved fin structure (i.e., Type-3) and increased number of fins (i.e., Type-5) configurations have more uniform temperature distribution and a higher melting rate by increasing the heat transfer cooperation between NC and thermal conduction. Low thermal conductivity causes poor performance in PCM (Phase Change Material) energy storage devices. The melting/charging of PCM in an LHTES system is greatly improved in this study by employing a porous metal foam (i.e., copper metal foam) or nanoparticle (i.e., Cu, CuO and Al2O3). The impact of nanoparticle volume fraction and metal foam porosity on the LHTES system's melting/charging performance is also investigated using the enthalpy-porosity technique. According to the results, PCM's melting/charging time is lowered by 63.4% when nanoparticles are mixed in and incorporated with metal foam for the Fourier number varies from 0.014 to 0.158 at a constant Stefan number of 0.20. PCM melting/charging time decreased when the metal foam porosity decreased or increased in the volume fraction of nanoparticles. High porosity metal foams with low volume fractions of nanoparticles can increase melting performance since it assures minimum PCM volume and increases natural convection.
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| 40. |
- Saini, P., et al.
(författare)
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Performance enhancement of fin and tube heat exchanger employing curved delta winglet vortex generator with circular punched holes
- 2023
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Ingår i: International Journal of Thermofluids. - : Elsevier B.V.. - 2666-2027. ; 20
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Tidskriftsartikel (refereegranskat)abstract
- The generation of vortices has recently gained attention as a potential passive technique for improving air-side heat transfer in a fin and tube heat exchanger. This study proposes novel configurations of a curved delta winglet vortex generator (CDWVG) with and without circular holes to improve heat transfer in FTHEs. The present study utilizes a three-dimensional numerical analysis to investigate the thermal-hydraulic performance analysis of fin and tube heat exchanger (FTHE) with curved delta winglet vortex generators (CDWVG) with or without circular holes, operating across a wide Reynolds number range (i.e., from 400 to 2000). In addition to being arranged in vertical and horizontal configurations, the CDWVGs are oriented in the same way as the flow direction. Therefore, the pressure distribution, temperature distribution, and flow structure distribution of an FTHE with a four-in-line circular tube configuration are analyzed and compared between FTHE without vortex generator (VG) and five different configurations of CDWVG (i.e., CDWVG without hole, CDWVG with 1 hole, CDWVG with 2 holes, CDWVG with 3 holes and CDWVG with 6 holes). The pressure drop (ΔP), London area goodness factor (LAGF) (j/f), Nusselt number (Nu), and Colburn factor (j) are also used to evaluate the thermo-hydraulic performance of FTHE. The FHTE performance with CDWVGs can be affected by the number of punched holes, which is evaluated using a dimensionless number including Performance Evaluation Criteria (PEC), Colburn factor, etc. The thermo-hydraulic efficiency of the FTHE is improved significantly by using CDWVGs with circular punched holes. Nusselt number decreases across all the VG configurations (i.e., CDWVG without hole, CDWVG with 1 hole, CDWVG with 2 holes, CDWVG with 3 holes, and CDWVG with 6 holes) due to the lower flow resistance. Compared to other CDWVG configurations, the 6-hole configuration of CDWVG is the most effective. The Nusselt number of CDWVG with 6 holes increases by 77.25% and 42.51% at Reynolds numbers of 400 and 2000, with respect to fin and tube heat exchangers without vortex generator, respectively. On the other hand, friction is decreased by 5.11%. Therefore, when considering the London area goodness factor, CDWVG with six holes is found to be superior to other CDWVG configurations. © 2023 The Authors
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| 41. |
- Saini, P., et al.
(författare)
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Performance enhancement of fin and tube heat exchanger employing curved trapezoidal winglet vortex generator with circular punched holes
- 2023
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Ingår i: International Journal of Heat and Mass Transfer. - : Elsevier BV. - 0017-9310 .- 1879-2189. ; 209
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Tidskriftsartikel (refereegranskat)abstract
- Vortex generation is a potential passive technology for increasing the heat transfer rate in the air side of fin and tube heat exchangers (FTHEs). This study proposes novel configurations of a curved trapezoidal winglet vortex generator (CTWVG) with and without circular holes to improve heat transfer in FTHEs. As per the literature, the streamlined form of the trapezoidal winglet demonstrates high heat transfer enhancement with low flow loss and pressure drop. But still, different design configurations are possible to augment the heat transfer characteristics of CTWVG further. The current study investigates the novel configurations of CTWVG (i.e., CTWVG without hole, CTWVG with 1 hole, CTWVG with 2 holes, CTWVG with 3 holes and CTWVG with 6 holes). A three-dimensional computational model is utilized to evaluate the thermal-hydraulic efficiency of FTHEs fitted with CTWVGs with or without circular holes for Reynolds numbers ranging from 400 to 2000. A common flow-down configuration of the CTWVG with circular tubes array is used to reduce the wake region. The thermo-hydraulic performance and flow structure of FTHE with four inline circular tube configurations are compared without VG and CTWVG with or without holes. Pressure drop (ΔP), Nusselt number (Nu), friction factor (f), Colburn factor (j), and London area goodness factor (j/f) are used for the thermal-hydraulic performance comparison. Results show that the number of punched holes has an impact on the FTHE performance, which is measured using a dimensionless number as performance evaluation criteria (i.e., (j/jo)/(f/fo)). CTWVGs with circular punched holes significantly increase the FTHE's thermo-hydraulic performance. The results indicate that the flow resistance is reduced in all cases (i.e., VG with no holes, VG with 6 holes, VG with 3 holes, VG with 2 holes, and VG with 1 hole) with a minor decrease in the Nusselt number. The CTWVG with six holes performs better than other CTWVG configurations. At Reynolds numbers 400 and 2000, the Nusselt number for CTWVG with six holes enhanced by 75.25% and 40.10%; pressure drop increased by 107.88% and 125.51%, respectively. On the other hand, friction is reduced by a factor of 8.1% in CTWVG with 6 holes compared to CTWVG without holes. The CTWVG with six holes performs better than other CTWVG configurations reported in the literature [48,54]. HTPF has increased by 30.96% (compared to rectangular winglet [48]) and 27.69% (compared to curved rectangular winglet [54]) with respect to values reported in the literature. The London area goodness factor (LAGF) has been increased by 275% compared to Modi et al. [48]. © 2023
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| 42. |
- Saini, P., et al.
(författare)
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Performance evaluation of a parabolic trough collector with a uniform helical wire coil flow insert
- 2024
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Ingår i: Results in Engineering (RINENG). - : Elsevier. - 2590-1230. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- Solar energy is an extremely useful and dependable renewable energy source for meeting our society's diverse energy demands. Solar concentrator-based energy systems are currently the most efficient methods of using solar energy. Among these technologies, the parabolic trough collector is a mature and effective concentrating solar power technology with a wide range of real-world applications using solar alone or in combination with other energy sources. Flow insert is a potential approach for improving parabolic trough solar collector performance through enhanced heat transfer and heat absorption. The purpose of this study is to determine the feasibility of using a uniform helical wire coil flow insert in the LS-2 parabolic trough solar collector module. A computational fluid dynamic model developed in Ansys 18.1 is used in the current investigation. A uniform helical wire coil flow insert is modeled and compared with the plain tube without any insert inside it. Flow analysis, overall efficiency, exergy efficiency, and thermal efficiency are compared in the evaluation process. The overall efficiency and exergy efficiency of the parabolic trough collector are the most critical criteria in determining its performance. The parabolic trough collector is examined using a range of inlet fluid temperatures ranging from 303 K to 603 K and a volumetric flow rate of 50 L per minute to 250 L per minute. The pumping work is found to be the lowest, indicating that the increase in pressure drop has a negligible effect on the overall system performance. For the flow rate of 50 L per minute and inlet heat transfer fluid temperature of 303 K, the overall, exergy and thermal efficiency using a uniform helical wire coil flow insert are found to be 2.07 %, 2.1 %, and 2.2 %, respectively. © 2024 The Authors
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| 43. |
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| 44. |
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| 45. |
- Sharma, Janpriy, et al.
(författare)
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Avenues of decarbonisation in the dynamics of processed food supply chains : Towards responsible production consumption
- 2024
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Ingår i: Heliyon. - : Cell Press. - 2405-8440. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Nowadays, the demand for processed food items is surging. To fulfil the enhanced demand, a significant impact is laid on the environment, which enhances the carbon footprint being generated. Hence, to overcome this, the avenues of decarbonisation need to be explored. The presented work is aimed at promoting the decarbonisation of the existing practices within the processed food supply chains. It finds strong compliance with the sustainable development goal (SDG-12), focusing on responsible production-consumption mechanisms. For the same, key enactors of decarbonisation are identified and mapped with the practices at various stages of food supply chains, i.e. upstream, downstream, and other allied practices. Based upon these enactors, a relational, hierarchical framework is developed to provide a comprehensive perspective on complex intricacies. This framework is analysed with an innovative approach which comprises the fundamentals of Interval-Valued Intuitionistic Hesitant Fuzzy Set with the Entropy measures. It results in the outranking of the enactors relative to its importance in the decarbonisation of processed food supply chains. Furthermore, the empirical findings are validated by the sensitivity analysis to felicitate robust decision-making. The outcomes of the presented work provide a roadmap and stepped approach to achieve the decarbonisation goals and make productionconsumption mechanisms sustainable. It finds implications in the development of the framework, policy formulation, and decisional attributes for the decarbonisation of food supply chains. It focuses on the adoption of strategies that align with global efforts to mitigate climate change and promote a sustainable future.
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| 46. |
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| 47. |
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| 48. |
- Singh, Anirudh, et al.
(författare)
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Computational Study on Parametric Variation with Solar Heat Induction of an Entrained Flow Gasifier
- 2022
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Ingår i: Energies. - : MDPI AG. - 1996-1073. ; 15:11
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Tidskriftsartikel (refereegranskat)abstract
- Gasification has played an important role in the sustainable use of waste biomass, providing useful combustible gases in the process. Gasification has an important role in waste management and promotes energy independence for many oil-deficit countries. The gasification process has been studied by various researchers, and improvements have been achieved in its sub-processes such as devolatilization, feed input methods, and so on. We examined the influence of gasifier operation parameters, such as oxidizer content, moisture content in the feedstock, and solar flux input inside the gasifier, on the temperature distribution, velocity distribution, and product gas yields of the gasifier. The results indicate that inducing solar energy at different stages of the gasifier leads to different yields of product gas composition (CO and H-2).
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| 49. |
- Singh, A., et al.
(författare)
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Solar Assisted Gasification
- 2019. - 1
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Ingår i: Advances in Solar Energy Research. - Singapore : Springer. - 9789811333019 - 9789811333026 ; , s. 551-576
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Bokkapitel (refereegranskat)
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| 50. |
- Singh, S., et al.
(författare)
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A novel hybrid grey-fuzzy optimization model for assessment of solar technologies considering different scenarios of the Indian market
- 2024
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Ingår i: Energy Reports. - : Elsevier. - 2352-4847. ; 11, s. 2023-2034
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Tidskriftsartikel (refereegranskat)abstract
- This paper examines the various solar photovoltaic technologies available in India. Seven commercially available photovoltaic technologies are compared using thirteen criteria that mainly contribute to sustainability, such as social, economic, and environmental, along with technical criteria under various conditions. Three distinct cases were developed (case I: considering all the thirteen criteria, case II: considering twelve criteria and freezing LCOE criteria, and case III: considering twelve criteria and freezing efficiency criteria) to determine the best technology available for multiple stakeholders to invest in at different conditions. The assessment integrates grey system theory, fuzzy set theory, and multi-criteria decision-making methods. The grey and fuzzy-based Analytical Hierarchy Process is used to determine the significance of the criteria. In contrast, the grey and fuzzy-based COmplex PRoportional ASsessment is used for ranking these technologies. According to the results, the most favorable technology in all three cases is Cadmium Telluride (CdTe) if developed in the Indian zone. The CdTe technology has a lower levelized cost of electricity and module cost, high efficiency, and, most importantly, high technological maturity compared to other technologies. © 2024 The Authors
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