Search for: fused-salts
Article Ceramics International ; 2016 ; 02728842 (ISSN) ; Bavand Vandchali, M ; Golestani Fard, F ; Nemati, A ; Sharif University of Technology
A silicon carbide coating was formed on the surface of graphite flakes by reaction of molten Si with carbon at 1100-1300. °C in a 95%KCl-5%NaF molten salt under Ar atmosphere. The effect of temperature and Si/graphite ratio in the initial mixture on the quality and the amount of SiC were investigated by XRD and SEM/EDS analyses. Also, the water wettability, oxidation resistance and zeta potential of un-coated and coated graphite were examined by TGA analysis and sedimentation test. The results show the amount of coating to increase in the coated flakes with increasing temperature and Si/graphite ratio. The SiC coating improves water wettability of graphite and acts as a protective layer to...
Chromium carbonitride coating produced on DIN 1.2210 steel by thermo-reactive deposition technique: Thermodynamics, kinetics and modeling, Article Surface and Coatings Technology ; Volume 225 , 2013 , Pages 1-10 ; 02578972 (ISSN) ; Nazari, A ; Khoie, S. M. M ; Khalaj, M. J ; Pouraliakbar, H ; Sharif University of Technology
A duplex surface treatment on DIN 1.2210 steel has been developed involving nitriding and followed by chromium thermo-reactive deposition (TRD) techniques. The TRD process was performed in molten salt bath at 550, 625 and 700°C for 1-14h. The process formed a thickness up to 9.5μm of chromium carbonitride coatings on a hardened diffusion zone. Characterization of the coatings by means of scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) indicates that the compact and dense coatings mainly consist of Cr(C,N) and Cr2(C,N) phase. All the growth processes of the chromium carbonitride obtained by TRD technique followed a parabolic kinetics. Activation energy (Q) for the...
Evaluation of hot corrosion behavior of plasma sprayed thermal barrier coatings with graded intermediate layer and double ceramic top layer, Article Surface and Coatings Technology ; Volume 288 , 2016 , Pages 36-45 ; 02578972 (ISSN) ; Javadi, A. H ; Ghasali, E ; Shahbazkhan, A ; Shakhesi, S ; Sharif University of Technology
In the present work, the hot corrosion behavior of two types of multilayer plasma sprayed TBC were investigated and compared with functionally graded and conventional TBCs. These kinds of multilayer coatings consisted of nano/μ alumina as a top coat on YSZ layer, a metallic bond coat and a functionally graded intermediate layer deposited between YSZ and bond coat layers. All the layers were sprayed on the Ni-base super alloy substrate. The hot corrosion resistance of the plasma sprayed coatings was examined at 1050 °C for 40 h, using a fused mixture of 45 wt% Na2SO4 + 55wt%V2O5. Before and after hot corrosion, the microstructure and phase analysis of the coating were studied using scanning...
Part load behavior of molten salt cavity receiver solar tower plants under storage mode operational mode, Article ASME 2016 10th International Conference on Energy Sustainability, ES 2016, collocated with the ASME 2016 Power Conference and the ASME 2016 14th International Conference on Fuel Cell Science, Engineering and Technology, 26 June 2016 through 30 June 2016 ; Volume 1 , 2016 ; 9780791850220 (ISBN) ; Shafiei Ghazani, A ; Taylor, R. A ; Saberi, P ; Sharif University of Technology
American Society of Mechanical Engineers 2016
The performance of the tower based concentrated solar thermal (CST-tower) plant is very sensitive to the operation strategy of the plant and the incident heat flux on the receiver. To date, most studies have been examined only the design mode characteristics of the cavity receivers, but this paper significantly expands the literature by considering non-design operating conditions of this important sub-component of the CST-tower plants. A feasible non-design operating conditions of the cavity receivers that was considered in this study is the storage mode of operation. Two practical dynamic control strategies were examined then to find the most efficient approach: fixed solar field mass...
Electrodeposition of Al, Mn, and Al-Mn alloy on aluminum electrodes from molten salt (AlCl3-NaCl-KCl), Article Journal of Applied Electrochemistry ; Volume 39, Issue 8 , 2009 , Pages 1297-1303 ; 0021891X (ISSN) ; Maleki, A ; Danaee, I ; Gobal, F ; Mahjani, M. G ; Sharif University of Technology
Electrochemical deposition of aluminum and manganese from basic and acidic molten AlCl3-NaCl-KCl mixture on an aluminum electrode at 180 °C was studied by the methods of voltammetry, and potential and current transient. The deposition of aluminum was found to proceed via a nucleation/growth mechanism in basic melt, while the deposition of manganese was found to be diffusion controlled in basic melt. The diffusion coefficient of Mn2+ ions in basic melt, as derived by voltammetry was in agreement with the deductions of transient methods. Analysis of the chronoamperograms indicates that the deposition of manganese on Al was controlled by 3D diffusion controlled nucleation and growth. The...
Electrocrystallization of Pb and Pb assisted Al on aluminum electrode from molten salt (AlCl3-NaCl-KCl), Article Journal of Alloys and Compounds ; Volume 478, Issue 1-2 , 2009 , Pages 83-88 ; 09258388 (ISSN) ; Danaee, I ; Maleki, A ; Gobal, F ; Mahjani, M. G ; Sharif University of Technology
Electrochemical deposition of aluminum and lead from basic molten AlCl3-NaCl-KCl mixture on an aluminum electrode at 180 °C was studied by the methods of voltammetry, potential and current transient and constant current deposition. The deposition of aluminum was found to proceed via a nucleation/growth mechanism, while the deposition of lead was found to be diffusion controlled. The diffusion coefficient calculated for Pb2+ ions in basic melt by voltammetry was in agreement with the deductions of transient method. The analysis of the chronoamperograms indicates that the deposition process of lead on Al substrates was controlled by 3D diffusion control, nucleation and growth. The processes...
Annual comparative performance and cost analysis of high temperature, sensible thermal energy storage systems integrated with a concentrated solar power plant, Article Solar Energy ; Volume 153 , 2017 , Pages 153-172 ; 0038092X (ISSN) ; Taylor, R. A ; Nithyanandam, K ; Shafiei Ghazani, A ; Sharif University of Technology
Elsevier Ltd 2017
The present study conducts a comprehensive comparative techno-economic analysis of some near-term sensible thermal energy storage (TES) alternatives to the ‘standard’ two-tank molten salt system for concentrated solar power (CSP) plants. As such, we conducted detailed, relative annual transient simulations for single-medium thermocline (SMT), dual-media thermocline (DMT), and shell-and-tube (ST) systems. To be consistent with recent literature, the DMT and ST systems use concrete with a porosity of 0.2 (e.g. where concrete occupies 80% of the system) as their low cost filler material. The systems were integrated into a validated 19.9 MWe Gemasolar CSP model, which has a solar multiple of...