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Zafar Said - One of the best experts on this subject based on the ideXlab platform.

  • experimental investigation of thermo physical properties heat transfer pumping power entropy generation and Exergy Efficiency of nanodiamond fe3o4 60 40 water ethylene glycol hybrid nanofluid flow in a tube
    Thermal science and engineering, 2021
    Co-Authors: Syam L Sundar, Zafar Said, Solomon Mesfin, Venkata E Ramana, Antonio C M Sousa
    Abstract:

    Abstract The synthesis method of in-situ/chemical co-precipitation was implemented for the addition of Fe3O4 nanoparticles on the surface of nanodiamond (ND) nanoparticles, and it is characterized by using x-ray diffraction, transmission electron microscopy and the magnetic property was estimated from the vibrating sample magnetometer. The 60:40% water-ethylene glycol mixture is used as a base fluid for the preparation of ND-Fe3O4 hybrid nanofluids. Experimental techniques are used to measure the thermophysical properties at various particle volume loadings, and temperatures and the obtained data is validated with literature data. The heat transfer, friction factor, and pumping power are evaluated at particle volume loadings from 0.05% to 0.2% and in the Reynolds number range from 2105 to 8126. The concepts of the second law of thermodynamics are used to evaluate the thermal entropy generation, frictional entropy generation and Exergy Efficiency of the hybrid nanofluids. The thermal conductivity enhancements are 5.03% and 12.79%, whereas, the viscosity enhancements are 108% and 50.84% at particle loading of 0.2% at temperatures of 20 °C and 60 °C in comparison with base fluid. The Nusselt number is augmented to 15.65%; thermal entropy generation is reduced to 20%, frictional entropy generation is augmented to 272.48% and Exergy Efficiency is increased to 38.24% with a maximum penalty in friction factor of 1.128-times at 0.2% particle loading and a Reynolds number of 7502 against base fluid data. New equations are modelled to evaluate the thermophysical properties, Nusselt number, and friction factor.

  • energy and Exergy Efficiency of a flat plate solar collector using ph treated al2o3 nanofluid
    Journal of Cleaner Production, 2016
    Co-Authors: R Saidur, Zafar Said, M A Sabiha, Arif Hepbasli, N A Rahim
    Abstract:

    Abstract Application of nanofluid to increase the thermal Efficiency of a traditional solar collector is getting tremendous attention among the scientific community. Al 2 O 3 –water nanofluid, as a working fluid and its effect on the energy and Exergy efficiencies of a flat plate solar collector was examined experimentally. Volume fraction used for this study was 0.1% and 0.3%, while the size of the nanoparticles was ∼13 nm. Experiments were carried out using a stable nanofluid which was obtained by controlling the pH of the solution over a period of 30 days. The mass flow rates of the nanofluid varied from 0.5 to 1.5 kg/min. Energy and Exergy efficiencies of a flat plate solar collector using water and nanofluids as working fluids were matched. The results revealed that nanofluids increased the energy Efficiency by 83.5% for 0.3% v/v and 1.5 kg/min, whereas the Exergy Efficiency was enhanced by up to 20.3% for 0.1% v/v and 1 kg/min. Thermal Efficiency of the system was found to be more than 50% compared to the existing system available in the literature. New findings on the stability and Exergy analysis of the solar collector system operated with a pH controlled nanofluid are reported.

  • energy and Exergy Efficiency of a flat plate solar collector using ph treated al2o3 nanofluid
    Journal of Cleaner Production, 2016
    Co-Authors: R Saidur, Zafar Said, M A Sabiha, Arif Hepbasli, N A Rahim
    Abstract:

    Application of nanofluid to increase the thermal Efficiency of a traditional solar collector is getting tremendous attention among the scientific community. Al2O3-water nanofluid, as a working fluid and its effect on the energy and Exergy efficiencies of a flat plate solar collector was examined experimentally. Volume fraction used for this study was 0.1% and 0.3%, while the size of the nanoparticles was similar to 13 nm. Experiments were carried out using a stable nanofluid which was obtained by controlling the pH of the solution over a period of 30 days. The mass flow rates of the nanofluid varied from 0.5 to 1.5 kg/min. Energy and Exergy efficiencies of a flat plate solar collector using water and nanofluids as working fluids were matched. The results revealed that nanofluids increased the energy Efficiency by 83.5% for 0.3% v/v and 1.5 kg/min, whereas the Exergy Efficiency was enhanced by up to 20.3% for 0.1% v/v and 1 kg/min. Thermal Efficiency of the system was found to be more than 50% compared to the existing system available in the literature. New findings on the stability and Exergy analysis of the solar collector system operated with a pH controlled nanofluid are reported. (C) 2015 Elsevier Ltd. All rights reserved.

  • energy and Exergy Efficiency of a flat plate solar collector using ph treated al2o3 nanofluid
    Journal of Cleaner Production, 2016
    Co-Authors: R Saidur, Zafar Said, M A Sabiha, Arif Hepbasli, N A Rahim
    Abstract:

    Abstract Application of nanofluid to increase the thermal Efficiency of a traditional solar collector is getting tremendous attention among the scientific community. Al2O3–water nanofluid, as a working fluid and its effect on the energy and Exergy efficiencies of a flat plate solar collector was examined experimentally. Volume fraction used for this study was 0.1% and 0.3%, while the size of the nanoparticles was ∼13 nm. Experiments were carried out using a stable nanofluid which was obtained by controlling the pH of the solution over a period of 30 days. The mass flow rates of the nanofluid varied from 0.5 to 1.5 kg/min. Energy and Exergy efficiencies of a flat plate solar collector using water and nanofluids as working fluids were matched. The results revealed that nanofluids increased the energy Efficiency by 83.5% for 0.3% v/v and 1.5 kg/min, whereas the Exergy Efficiency was enhanced by up to 20.3% for 0.1% v/v and 1 kg/min. Thermal Efficiency of the system was found to be more than 50% compared to the existing system available in the literature. New findings on the stability and Exergy analysis of the solar collector system operated with a pH controlled nanofluid are reported.

  • thermophysical properties of single wall carbon nanotubes and its effect on Exergy Efficiency of a flat plate solar collector
    Solar Energy, 2015
    Co-Authors: R Saidur, Zafar Said, M A Sabiha, N A Rahim, M R Anisur
    Abstract:

    In order to enhance thermal Efficiency of a flat plate solar collector, the effects of thermo-physical properties of short Single Wall Carbon Nanotubes (SWCNTs) suspended in water was investigated in this study. Sodium dodecyl sulphate was used as a dispersant for preparing a stable nanofluid. Subsequently, the nanofluid was comprehensively characterized by particle size measurement and spectroscopic technique. Specific heat with the increase of particle loading and temperature was investigated. Thermal conductivity increment also showed a linear dependence on particle concentration and temperature. Viscosity of the nanofluids and water reduced with the increase of temperature and increased with the particle loading. Using improved thermo-physical properties of the nanofluid, the maximum energy and Exergy Efficiency of fiat plate collector was enhanced up to 95.12% and 26.25% compared to water which was 42.07% and 8.77%, respectively. This low Exergy Efficiency shows that flat plate collectors still require substantial enhancement. To the authors' knowledge, SWCNTs-H2O was used as the functioning fluid for the first time to investigate both the thermos-physical properties as well as the increase in thermal Efficiency of a flat plate solar collector. (C) 2015 Elsevier Ltd. All rights reserved.

Yang Shi - One of the best experts on this subject based on the ideXlab platform.

  • comparison between regenerative organic rankine cycle rorc and basic organic rankine cycle borc based on thermoeconomic multi objective optimization considering Exergy Efficiency and levelized energy cost lec
    Energy Conversion and Management, 2015
    Co-Authors: Yongqiang Feng, Yaning Zhang, Jinfu Yang, Yang Shi
    Abstract:

    Abstract Based on the thermoeconomic multi-objective optimization by using non-dominated sorting genetic algorithm (NSGA-II), considering both thermodynamic performance and economic factors, the thermoeconomic comparison of regenerative organic Rankine cycles (RORC) and basic organic Rankine cycles (BORC) are investigated. The effects of five key parameters including evaporator outlet temperature, condenser temperature, degree of superheat, pinch point temperature difference and degree of supercooling on the Exergy Efficiency and levelized energy cost (LEC) are examined. Meanwhile, the Pareto frontier solution with bi-objective for maximizing Exergy Efficiency and minimizing LEC is obtained and compared with the corresponding single-objective solutions. Research demonstrates that there is a significant negative correlation between thermodynamic performance and economic factors. And the optimum Exergy Efficiency and LEC for the Pareto-optimal solution of the RORC are 55.97% and 0.142 $/kW h, respectively, which are 8.1% higher Exergy Efficiency and 21.1% more LEC than that of the BORC under considered condition. Highest Exergy and thermal efficiencies are accompanied with lowest net power output and worst economic performance. Furthermore, taking the net power output into account, detailed investigation on the three-objective optimization for maximizing Exergy Efficiency, maximizing net power output and minimizing LEC is discussed.

  • comparison between regenerative organic rankine cycle rorc and basic organic rankine cycle borc based on thermoeconomic multi objective optimization considering Exergy Efficiency and levelized energy cost lec
    Energy Conversion and Management, 2015
    Co-Authors: Yongqiang Feng, Yaning Zhang, Jinfu Yang, Yang Shi
    Abstract:

    Based on the thermoeconomic multi-objective optimization by using non-dominated sorting genetic algorithm (NSGA-II), considering both thermodynamic performance and economic factors, the thermoeconomic comparison of regenerative organic Rankine cycles (RORC) and basic organic Rankine cycles (BORC) are investigated. The effects of five key parameters including evaporator outlet temperature, condenser temperature, degree of superheat, pinch point temperature difference and degree of supercooling on the Exergy Efficiency and levelized energy cost (LEC) are examined. Meanwhile, the Pareto frontier solution with bi-objective for maximizing Exergy Efficiency and minimizing LEC is obtained and compared with the corresponding single-objective solutions. Research demonstrates that there is a significant negative correlation between thermodynamic performance and economic factors. And the optimum Exergy Efficiency and LEC for the Pareto-optimal solution of the RORC are 55.97% and 0.142 $/kW h, respectively, which are 8.1% higher Exergy Efficiency and 21.1% more LEC than that of the BORC under considered condition. Highest Exergy and thermal efficiencies are accompanied with lowest net power output and worst economic performance. Furthermore, taking the net power output into account, detailed investigation on the three-objective optimization for maximizing Exergy Efficiency, maximizing net power output and minimizing LEC is discussed. (C) 2015 Elsevier Ltd. All rights reserved.

N A Rahim - One of the best experts on this subject based on the ideXlab platform.

  • energy and Exergy Efficiency of a flat plate solar collector using ph treated al2o3 nanofluid
    Journal of Cleaner Production, 2016
    Co-Authors: R Saidur, Zafar Said, M A Sabiha, Arif Hepbasli, N A Rahim
    Abstract:

    Abstract Application of nanofluid to increase the thermal Efficiency of a traditional solar collector is getting tremendous attention among the scientific community. Al 2 O 3 –water nanofluid, as a working fluid and its effect on the energy and Exergy efficiencies of a flat plate solar collector was examined experimentally. Volume fraction used for this study was 0.1% and 0.3%, while the size of the nanoparticles was ∼13 nm. Experiments were carried out using a stable nanofluid which was obtained by controlling the pH of the solution over a period of 30 days. The mass flow rates of the nanofluid varied from 0.5 to 1.5 kg/min. Energy and Exergy efficiencies of a flat plate solar collector using water and nanofluids as working fluids were matched. The results revealed that nanofluids increased the energy Efficiency by 83.5% for 0.3% v/v and 1.5 kg/min, whereas the Exergy Efficiency was enhanced by up to 20.3% for 0.1% v/v and 1 kg/min. Thermal Efficiency of the system was found to be more than 50% compared to the existing system available in the literature. New findings on the stability and Exergy analysis of the solar collector system operated with a pH controlled nanofluid are reported.

  • energy and Exergy Efficiency of a flat plate solar collector using ph treated al2o3 nanofluid
    Journal of Cleaner Production, 2016
    Co-Authors: R Saidur, Zafar Said, M A Sabiha, Arif Hepbasli, N A Rahim
    Abstract:

    Application of nanofluid to increase the thermal Efficiency of a traditional solar collector is getting tremendous attention among the scientific community. Al2O3-water nanofluid, as a working fluid and its effect on the energy and Exergy efficiencies of a flat plate solar collector was examined experimentally. Volume fraction used for this study was 0.1% and 0.3%, while the size of the nanoparticles was similar to 13 nm. Experiments were carried out using a stable nanofluid which was obtained by controlling the pH of the solution over a period of 30 days. The mass flow rates of the nanofluid varied from 0.5 to 1.5 kg/min. Energy and Exergy efficiencies of a flat plate solar collector using water and nanofluids as working fluids were matched. The results revealed that nanofluids increased the energy Efficiency by 83.5% for 0.3% v/v and 1.5 kg/min, whereas the Exergy Efficiency was enhanced by up to 20.3% for 0.1% v/v and 1 kg/min. Thermal Efficiency of the system was found to be more than 50% compared to the existing system available in the literature. New findings on the stability and Exergy analysis of the solar collector system operated with a pH controlled nanofluid are reported. (C) 2015 Elsevier Ltd. All rights reserved.

  • energy and Exergy Efficiency of a flat plate solar collector using ph treated al2o3 nanofluid
    Journal of Cleaner Production, 2016
    Co-Authors: R Saidur, Zafar Said, M A Sabiha, Arif Hepbasli, N A Rahim
    Abstract:

    Abstract Application of nanofluid to increase the thermal Efficiency of a traditional solar collector is getting tremendous attention among the scientific community. Al2O3–water nanofluid, as a working fluid and its effect on the energy and Exergy efficiencies of a flat plate solar collector was examined experimentally. Volume fraction used for this study was 0.1% and 0.3%, while the size of the nanoparticles was ∼13 nm. Experiments were carried out using a stable nanofluid which was obtained by controlling the pH of the solution over a period of 30 days. The mass flow rates of the nanofluid varied from 0.5 to 1.5 kg/min. Energy and Exergy efficiencies of a flat plate solar collector using water and nanofluids as working fluids were matched. The results revealed that nanofluids increased the energy Efficiency by 83.5% for 0.3% v/v and 1.5 kg/min, whereas the Exergy Efficiency was enhanced by up to 20.3% for 0.1% v/v and 1 kg/min. Thermal Efficiency of the system was found to be more than 50% compared to the existing system available in the literature. New findings on the stability and Exergy analysis of the solar collector system operated with a pH controlled nanofluid are reported.

  • thermophysical properties of single wall carbon nanotubes and its effect on Exergy Efficiency of a flat plate solar collector
    Solar Energy, 2015
    Co-Authors: R Saidur, Zafar Said, M A Sabiha, N A Rahim, M R Anisur
    Abstract:

    In order to enhance thermal Efficiency of a flat plate solar collector, the effects of thermo-physical properties of short Single Wall Carbon Nanotubes (SWCNTs) suspended in water was investigated in this study. Sodium dodecyl sulphate was used as a dispersant for preparing a stable nanofluid. Subsequently, the nanofluid was comprehensively characterized by particle size measurement and spectroscopic technique. Specific heat with the increase of particle loading and temperature was investigated. Thermal conductivity increment also showed a linear dependence on particle concentration and temperature. Viscosity of the nanofluids and water reduced with the increase of temperature and increased with the particle loading. Using improved thermo-physical properties of the nanofluid, the maximum energy and Exergy Efficiency of fiat plate collector was enhanced up to 95.12% and 26.25% compared to water which was 42.07% and 8.77%, respectively. This low Exergy Efficiency shows that flat plate collectors still require substantial enhancement. To the authors' knowledge, SWCNTs-H2O was used as the functioning fluid for the first time to investigate both the thermos-physical properties as well as the increase in thermal Efficiency of a flat plate solar collector. (C) 2015 Elsevier Ltd. All rights reserved.

Yongqiang Feng - One of the best experts on this subject based on the ideXlab platform.

  • comparison between regenerative organic rankine cycle rorc and basic organic rankine cycle borc based on thermoeconomic multi objective optimization considering Exergy Efficiency and levelized energy cost lec
    Energy Conversion and Management, 2015
    Co-Authors: Yongqiang Feng, Yaning Zhang, Jinfu Yang, Yang Shi
    Abstract:

    Abstract Based on the thermoeconomic multi-objective optimization by using non-dominated sorting genetic algorithm (NSGA-II), considering both thermodynamic performance and economic factors, the thermoeconomic comparison of regenerative organic Rankine cycles (RORC) and basic organic Rankine cycles (BORC) are investigated. The effects of five key parameters including evaporator outlet temperature, condenser temperature, degree of superheat, pinch point temperature difference and degree of supercooling on the Exergy Efficiency and levelized energy cost (LEC) are examined. Meanwhile, the Pareto frontier solution with bi-objective for maximizing Exergy Efficiency and minimizing LEC is obtained and compared with the corresponding single-objective solutions. Research demonstrates that there is a significant negative correlation between thermodynamic performance and economic factors. And the optimum Exergy Efficiency and LEC for the Pareto-optimal solution of the RORC are 55.97% and 0.142 $/kW h, respectively, which are 8.1% higher Exergy Efficiency and 21.1% more LEC than that of the BORC under considered condition. Highest Exergy and thermal efficiencies are accompanied with lowest net power output and worst economic performance. Furthermore, taking the net power output into account, detailed investigation on the three-objective optimization for maximizing Exergy Efficiency, maximizing net power output and minimizing LEC is discussed.

  • comparison between regenerative organic rankine cycle rorc and basic organic rankine cycle borc based on thermoeconomic multi objective optimization considering Exergy Efficiency and levelized energy cost lec
    Energy Conversion and Management, 2015
    Co-Authors: Yongqiang Feng, Yaning Zhang, Jinfu Yang, Yang Shi
    Abstract:

    Based on the thermoeconomic multi-objective optimization by using non-dominated sorting genetic algorithm (NSGA-II), considering both thermodynamic performance and economic factors, the thermoeconomic comparison of regenerative organic Rankine cycles (RORC) and basic organic Rankine cycles (BORC) are investigated. The effects of five key parameters including evaporator outlet temperature, condenser temperature, degree of superheat, pinch point temperature difference and degree of supercooling on the Exergy Efficiency and levelized energy cost (LEC) are examined. Meanwhile, the Pareto frontier solution with bi-objective for maximizing Exergy Efficiency and minimizing LEC is obtained and compared with the corresponding single-objective solutions. Research demonstrates that there is a significant negative correlation between thermodynamic performance and economic factors. And the optimum Exergy Efficiency and LEC for the Pareto-optimal solution of the RORC are 55.97% and 0.142 $/kW h, respectively, which are 8.1% higher Exergy Efficiency and 21.1% more LEC than that of the BORC under considered condition. Highest Exergy and thermal efficiencies are accompanied with lowest net power output and worst economic performance. Furthermore, taking the net power output into account, detailed investigation on the three-objective optimization for maximizing Exergy Efficiency, maximizing net power output and minimizing LEC is discussed. (C) 2015 Elsevier Ltd. All rights reserved.

Farzad Veysi - One of the best experts on this subject based on the ideXlab platform.

  • development of a correlation for parameter controlling using Exergy Efficiency optimization of an al2o3 water nanofluid based flat plate solar collector
    Applied Thermal Engineering, 2016
    Co-Authors: Ehsan Shojaeizadeh, Farzad Veysi
    Abstract:

    The current study deals with the Exergy Efficiency optimization of an Al2O3/water nanofluid-based flat-plate solar collector according to a mathematical optimization (Sequential Quadratic Programming (SQP) method). This study takes into account Exergy Efficiency optimization when solar radiation and ambient temperature parameters are assumed to be uncontrollable and presented to a wide range of transient data of climatic conditions where these might take place during spring and summer seasons of Kermanshah (Iran), and perform two main cases as follows: (1) the fluid temperature at the inlet of solar collector, Ti, is independent of storage tank (open loop); (2) the fluid temperature at the inlet of solar collector, Ti, is influenced by the presence of storage tank (closed loop). In any conditions of each case studies (working fluid with and without nanoparticles), a suitable decreasing exponential correlation as function of Ta/Gt values (i.e. ambient temperature to solar radiation ratio) is developed for the optimized Exergy Efficiency and also well controlling independent parameters values (mass flow rate of fluid, nanoparticle volume concentration and collector inlet temperature). Also, it is concluded that each of optimized parameters and the optimum Exergy Efficiency is of a linear relation with each other.

  • Exergy Efficiency investigation and optimization of an al2o3 water nanofluid based flat plate solar collector
    Energy and Buildings, 2015
    Co-Authors: Ehsan Shojaeizadeh, Farzad Veysi, Ahmad Kamandi
    Abstract:

    Abstract The present study aims to investigate Exergy Efficiency of a Flat-plate solar collector containing Al2O3–water nanofluid as base fluid. The effect of various parameters like mass flow rate of fluid, nanoparticle volume concentration, collector inlet fluid temperature, solar radiation, and ambient temperature on the collector Exergy Efficiency is investigated. Also, the procedure to determine optimum values of nanoparticle volume concentration, mass flow rate of fluid, and collector inlet fluid temperature for maximum Exergy Efficiency delivery has been developed by means of interior-point method for constrained optimization under the given conditions. According to the results, each of these parameters can differently affect the collector Exergy by changing the value of the other parameters. The optimization results indicate that under the actual constraints, in both pure water and nanofluid cases the optimized Exergy Efficiency is increased with increasing solar radiation value. By suspending Al2O3 nanoparticles in the base fluid (water) the maximum collector Exergy Efficiency is increased about 1% and also the corresponding optimum values of mass flow rate of fluid and collector inlet fluid temperature are decreased about 68% and 2%, respectively.