The Experts below are selected from a list of 900 Experts worldwide ranked by ideXlab platform

Rangan Banerjee - One of the best experts on this subject based on the ideXlab platform.

  • thermal hydraulic simulation of absorber tubes in Linear Fresnel Reflector solar thermal system using relap
    Renewable Energy, 2016
    Co-Authors: Sudhansu S Sahoo, Suneet Singh, Rangan Banerjee
    Abstract:

    This paper presents thermal hydraulic modelling and simulation in the absorber tube of a Linear Fresnel Reflector (LFR) solar thermal system is carried out. The system is modelled using two-phase flow simulation software, RELAP5/MOD3.4. Although, RELAP5 is very commonly used in nuclear engineering design and simulation, it can be used for the simulation of solar thermal systems. Unlike other thermal systems like refrigerators and nuclear industries, there is significant heat loss from the surface of the absorber tube in a solar thermal system, which varies significantly with the temperature of the absorber tube wall. The recently developed temperature dependent heat loss has been incorporated in RELAP5 for variable net heat flux studies. The implementation of the temperature dependent heat losses has been verified by comparing the results obtained from RELAP with those obtained by Homogeneous Equilibrium Model. Parametric studies are carried out using verified RELAP model for different values of heat flux, mass flux, inlet subcooling and inlet pressure. The developed model can be considered as an effective tool for better and effective absorber LFR tube design under designed conditions.

  • experimental investigation and computational validation of heat losses from the cavity receiver used in Linear Fresnel Reflector solar thermal system
    Renewable Energy, 2013
    Co-Authors: Sudhansu S Sahoo, Shinu M Varghese, Suresh C Kumar, Shankar Viswanathan, Suneet Singh, Rangan Banerjee
    Abstract:

    This paper presents the analysis of heat losses from the trapezoidal cavity receiver used in Linear Fresnel Reflector (LFR) system. The experimental studies are conducted under laboratory conditions that are specially designed for this purpose. The effects of parameters such as the temperatures of the tube surface, depth of receiver, number of tubes, and emissivity of tubes are investigated. The loss of heat is taking place from the tube outer surface to glass cover, below the receiver and then glass cover to ambient. As part of this investigation, the system is modelled and simulated using computational fluid dynamics (CFD). After validation, contribution of convection and radiation to the total heat transfer are found out using CFD. Computational predictions are shown to be consistent with the experimental observations which show that the CFD model is a reliable tool for predicting heat loss and overall heat loss coefficient. It was found that losses due to convection are between 5 and 18% of the total heat losses.

  • steady state hydrothermal analysis of the absorber tubes used in Linear Fresnel Reflector solar thermal system
    Solar Energy, 2013
    Co-Authors: Sudhansu S Sahoo, Suneet Singh, Rangan Banerjee
    Abstract:

    Abstract Linear Fresnel Reflector (LFR) solar thermal system is a promising technology in solar thermal applications. In LFR system, parallel absorber tubes (usually 8–16) are located inside a trapezoidal cavity, which receives reflected solar flux from the mirrors situated below it. The fluid (usually water) inside the tubes undergoes phase change due to the incident solar flux. The focus of this paper is to carry out hydrothermal analysis in an absorber tube of a Linear Fresnel Reflector (LFR) solar thermal system. In the present work, a generic methodology to deal with steady state hydrothermal analysis of the absorber tubes has been discussed. The single phase regions as well as the two-phase region of the absorber tube have been analyzed. A one dimensional model has been used for the analysis for both the regions. In the two-phase region analysis is carried out under the assumption that the homogeneous equilibrium model is valid. For this hydrothermal analysis, the radiative and convective heat losses from the surface of the tube to the atmosphere are obviously needed. To obtain the heat losses, the computational analysis of the heat transfer in the trapezoidal cavity is carried out. The present model can be used to predict the variation of bulk fluid temperature, variation of heat transfer coefficient, pressure loss along the length under different mass flux and different solar flux, in single phase region. Similarly, variation of dryness fraction, local boiling two phase flow coefficient, and total pressure drop can be predicted for two phase region. This model can be used to understand and design for a better LFR system.

  • analysis of heat losses from a trapezoidal cavity used for Linear Fresnel Reflector system
    Solar Energy, 2012
    Co-Authors: Sudhansu S Sahoo, Suneet Singh, Rangan Banerjee
    Abstract:

    Abstract A Computational study to investigate the heat loss due to radiation and steady laminar natural convection flow in a trapezoidal cavity having eight absorber tubes for a Linear Fresnel Reflector (LFR) solar thermal system with uniformly heated tubes and adiabatic top wall and side walls has been performed. The losses due to convection and radiation were considered from the bottom glass cover. The results are validated with experimental data. Radiative component of losses from the cavity was found to be dominant which contributes around 80–90%. Heat loss characteristics have been studied for cavities of different depths. Simulations have been carried out for various values of heat transfer coefficient based on the wind speed below the glass surface. Effect of emissivities of the tubes on the heat loss has also been simulated. Flow pattern and isotherms inside the cavity for various depths have been analyzed. Finally, the correlation between the total average Nusselt number and its influencing parameters has been obtained for the proposed cavity.

Sudhansu S Sahoo - One of the best experts on this subject based on the ideXlab platform.

  • thermal hydraulic simulation of absorber tubes in Linear Fresnel Reflector solar thermal system using relap
    Renewable Energy, 2016
    Co-Authors: Sudhansu S Sahoo, Suneet Singh, Rangan Banerjee
    Abstract:

    This paper presents thermal hydraulic modelling and simulation in the absorber tube of a Linear Fresnel Reflector (LFR) solar thermal system is carried out. The system is modelled using two-phase flow simulation software, RELAP5/MOD3.4. Although, RELAP5 is very commonly used in nuclear engineering design and simulation, it can be used for the simulation of solar thermal systems. Unlike other thermal systems like refrigerators and nuclear industries, there is significant heat loss from the surface of the absorber tube in a solar thermal system, which varies significantly with the temperature of the absorber tube wall. The recently developed temperature dependent heat loss has been incorporated in RELAP5 for variable net heat flux studies. The implementation of the temperature dependent heat losses has been verified by comparing the results obtained from RELAP with those obtained by Homogeneous Equilibrium Model. Parametric studies are carried out using verified RELAP model for different values of heat flux, mass flux, inlet subcooling and inlet pressure. The developed model can be considered as an effective tool for better and effective absorber LFR tube design under designed conditions.

  • experimental investigation and computational validation of heat losses from the cavity receiver used in Linear Fresnel Reflector solar thermal system
    Renewable Energy, 2013
    Co-Authors: Sudhansu S Sahoo, Shinu M Varghese, Suresh C Kumar, Shankar Viswanathan, Suneet Singh, Rangan Banerjee
    Abstract:

    This paper presents the analysis of heat losses from the trapezoidal cavity receiver used in Linear Fresnel Reflector (LFR) system. The experimental studies are conducted under laboratory conditions that are specially designed for this purpose. The effects of parameters such as the temperatures of the tube surface, depth of receiver, number of tubes, and emissivity of tubes are investigated. The loss of heat is taking place from the tube outer surface to glass cover, below the receiver and then glass cover to ambient. As part of this investigation, the system is modelled and simulated using computational fluid dynamics (CFD). After validation, contribution of convection and radiation to the total heat transfer are found out using CFD. Computational predictions are shown to be consistent with the experimental observations which show that the CFD model is a reliable tool for predicting heat loss and overall heat loss coefficient. It was found that losses due to convection are between 5 and 18% of the total heat losses.

  • steady state hydrothermal analysis of the absorber tubes used in Linear Fresnel Reflector solar thermal system
    Solar Energy, 2013
    Co-Authors: Sudhansu S Sahoo, Suneet Singh, Rangan Banerjee
    Abstract:

    Abstract Linear Fresnel Reflector (LFR) solar thermal system is a promising technology in solar thermal applications. In LFR system, parallel absorber tubes (usually 8–16) are located inside a trapezoidal cavity, which receives reflected solar flux from the mirrors situated below it. The fluid (usually water) inside the tubes undergoes phase change due to the incident solar flux. The focus of this paper is to carry out hydrothermal analysis in an absorber tube of a Linear Fresnel Reflector (LFR) solar thermal system. In the present work, a generic methodology to deal with steady state hydrothermal analysis of the absorber tubes has been discussed. The single phase regions as well as the two-phase region of the absorber tube have been analyzed. A one dimensional model has been used for the analysis for both the regions. In the two-phase region analysis is carried out under the assumption that the homogeneous equilibrium model is valid. For this hydrothermal analysis, the radiative and convective heat losses from the surface of the tube to the atmosphere are obviously needed. To obtain the heat losses, the computational analysis of the heat transfer in the trapezoidal cavity is carried out. The present model can be used to predict the variation of bulk fluid temperature, variation of heat transfer coefficient, pressure loss along the length under different mass flux and different solar flux, in single phase region. Similarly, variation of dryness fraction, local boiling two phase flow coefficient, and total pressure drop can be predicted for two phase region. This model can be used to understand and design for a better LFR system.

  • analysis of heat losses from a trapezoidal cavity used for Linear Fresnel Reflector system
    Solar Energy, 2012
    Co-Authors: Sudhansu S Sahoo, Suneet Singh, Rangan Banerjee
    Abstract:

    Abstract A Computational study to investigate the heat loss due to radiation and steady laminar natural convection flow in a trapezoidal cavity having eight absorber tubes for a Linear Fresnel Reflector (LFR) solar thermal system with uniformly heated tubes and adiabatic top wall and side walls has been performed. The losses due to convection and radiation were considered from the bottom glass cover. The results are validated with experimental data. Radiative component of losses from the cavity was found to be dominant which contributes around 80–90%. Heat loss characteristics have been studied for cavities of different depths. Simulations have been carried out for various values of heat transfer coefficient based on the wind speed below the glass surface. Effect of emissivities of the tubes on the heat loss has also been simulated. Flow pattern and isotherms inside the cavity for various depths have been analyzed. Finally, the correlation between the total average Nusselt number and its influencing parameters has been obtained for the proposed cavity.

Suneet Singh - One of the best experts on this subject based on the ideXlab platform.

  • thermal hydraulic simulation of absorber tubes in Linear Fresnel Reflector solar thermal system using relap
    Renewable Energy, 2016
    Co-Authors: Sudhansu S Sahoo, Suneet Singh, Rangan Banerjee
    Abstract:

    This paper presents thermal hydraulic modelling and simulation in the absorber tube of a Linear Fresnel Reflector (LFR) solar thermal system is carried out. The system is modelled using two-phase flow simulation software, RELAP5/MOD3.4. Although, RELAP5 is very commonly used in nuclear engineering design and simulation, it can be used for the simulation of solar thermal systems. Unlike other thermal systems like refrigerators and nuclear industries, there is significant heat loss from the surface of the absorber tube in a solar thermal system, which varies significantly with the temperature of the absorber tube wall. The recently developed temperature dependent heat loss has been incorporated in RELAP5 for variable net heat flux studies. The implementation of the temperature dependent heat losses has been verified by comparing the results obtained from RELAP with those obtained by Homogeneous Equilibrium Model. Parametric studies are carried out using verified RELAP model for different values of heat flux, mass flux, inlet subcooling and inlet pressure. The developed model can be considered as an effective tool for better and effective absorber LFR tube design under designed conditions.

  • experimental investigation and computational validation of heat losses from the cavity receiver used in Linear Fresnel Reflector solar thermal system
    Renewable Energy, 2013
    Co-Authors: Sudhansu S Sahoo, Shinu M Varghese, Suresh C Kumar, Shankar Viswanathan, Suneet Singh, Rangan Banerjee
    Abstract:

    This paper presents the analysis of heat losses from the trapezoidal cavity receiver used in Linear Fresnel Reflector (LFR) system. The experimental studies are conducted under laboratory conditions that are specially designed for this purpose. The effects of parameters such as the temperatures of the tube surface, depth of receiver, number of tubes, and emissivity of tubes are investigated. The loss of heat is taking place from the tube outer surface to glass cover, below the receiver and then glass cover to ambient. As part of this investigation, the system is modelled and simulated using computational fluid dynamics (CFD). After validation, contribution of convection and radiation to the total heat transfer are found out using CFD. Computational predictions are shown to be consistent with the experimental observations which show that the CFD model is a reliable tool for predicting heat loss and overall heat loss coefficient. It was found that losses due to convection are between 5 and 18% of the total heat losses.

  • steady state hydrothermal analysis of the absorber tubes used in Linear Fresnel Reflector solar thermal system
    Solar Energy, 2013
    Co-Authors: Sudhansu S Sahoo, Suneet Singh, Rangan Banerjee
    Abstract:

    Abstract Linear Fresnel Reflector (LFR) solar thermal system is a promising technology in solar thermal applications. In LFR system, parallel absorber tubes (usually 8–16) are located inside a trapezoidal cavity, which receives reflected solar flux from the mirrors situated below it. The fluid (usually water) inside the tubes undergoes phase change due to the incident solar flux. The focus of this paper is to carry out hydrothermal analysis in an absorber tube of a Linear Fresnel Reflector (LFR) solar thermal system. In the present work, a generic methodology to deal with steady state hydrothermal analysis of the absorber tubes has been discussed. The single phase regions as well as the two-phase region of the absorber tube have been analyzed. A one dimensional model has been used for the analysis for both the regions. In the two-phase region analysis is carried out under the assumption that the homogeneous equilibrium model is valid. For this hydrothermal analysis, the radiative and convective heat losses from the surface of the tube to the atmosphere are obviously needed. To obtain the heat losses, the computational analysis of the heat transfer in the trapezoidal cavity is carried out. The present model can be used to predict the variation of bulk fluid temperature, variation of heat transfer coefficient, pressure loss along the length under different mass flux and different solar flux, in single phase region. Similarly, variation of dryness fraction, local boiling two phase flow coefficient, and total pressure drop can be predicted for two phase region. This model can be used to understand and design for a better LFR system.

  • analysis of heat losses from a trapezoidal cavity used for Linear Fresnel Reflector system
    Solar Energy, 2012
    Co-Authors: Sudhansu S Sahoo, Suneet Singh, Rangan Banerjee
    Abstract:

    Abstract A Computational study to investigate the heat loss due to radiation and steady laminar natural convection flow in a trapezoidal cavity having eight absorber tubes for a Linear Fresnel Reflector (LFR) solar thermal system with uniformly heated tubes and adiabatic top wall and side walls has been performed. The losses due to convection and radiation were considered from the bottom glass cover. The results are validated with experimental data. Radiative component of losses from the cavity was found to be dominant which contributes around 80–90%. Heat loss characteristics have been studied for cavities of different depths. Simulations have been carried out for various values of heat transfer coefficient based on the wind speed below the glass surface. Effect of emissivities of the tubes on the heat loss has also been simulated. Flow pattern and isotherms inside the cavity for various depths have been analyzed. Finally, the correlation between the total average Nusselt number and its influencing parameters has been obtained for the proposed cavity.

Peng Hu - One of the best experts on this subject based on the ideXlab platform.

  • experimental and optical performances of a solar cpv device using a Linear Fresnel Reflector concentrator
    Renewable Energy, 2020
    Co-Authors: Gang Wang, Fasi Wang, Tieliu Jiang, Zeshao Chen, Fan Shen, Peng Hu
    Abstract:

    Abstract A solar CPV device using a Linear Fresnel Reflector (LFR) concentrator is described. The design principle of the concentrator is provided. The solar concentrating processes are simulated by using the MCRT approach. A small scale test rig of the concentrator is constructed to investigate the actual optical and I–V performances of the CPV device. Both of the simulation and experimental results reveal that the proposed concentrator has a relatively high solar concentrating uniformity. The configuration and optical analyses of the concentrator are launched. The results show that the geometric concentrating ratio and ground utilization ratio both increase with the solar panel installing height increased. When the solar cell height is settled, the maximum value of ground utilization ratio exists with the mirror field width increased. The sun-tracking accuracy effect analysis is also carried out. The results indicate that the normalized optical efficiency of the CPV system using the LFR concentrator can be 0.62 or higher when the tracking error is less than 1°. A solar cell monomer and a cell module are used to carry out the I–V experiments. The test results of their energy conversion efficiencies are 14.7% and 13.6%, respectively.

  • novel design and thermodynamic analysis of a solar concentration pv and thermal combined system based on compact Linear Fresnel Reflector
    Energy, 2019
    Co-Authors: Gang Wang, Fasi Wang, Zeshao Chen, Fan Shen, Peng Hu
    Abstract:

    Abstract A novel solar concentration photovoltaic (PV) and thermal combined system based on compact Linear Fresnel Reflector (CLFR) concentrator is proposed. The configuration and structural design approach of the PV and thermal combined system are introduced. The spectral beam splitter is designed by using the Needle optimization approach. Solar concentrating processes are simulated and relevant results show a high solar concentrating uniformity provided by the proposed combined system. The investigations of optical performance and relevant influential factors reveal that there is an optimal solar panel installation height for the proposed combined system when the slope angle and width of solar cells are settled. The effect of sun tracking error on the optical performance is also studied. The energy conversion analysis is carried out and the results show that the PV and thermal combined system has higher PV conversion and overall energy efficiencies in comparison with the solar concentration PV system without beam splitter. Furthermore, the effect of solar thermal collector temperature is investigated and the results reveal that there is an optimal tube collector operating temperature which can lead to the maximum total output power and overall energy efficiency.

  • thermodynamic and optical analysis for a cpv t hybrid system with beam splitter and fully tracked Linear Fresnel Reflector concentrator utilizing sloped panels
    Solar Energy, 2014
    Co-Authors: Peng Hu, Qian Zhang, Zeshao Chen
    Abstract:

    Abstract Spectral splitting technology that separates solar spectrum into several parts and enables different energy conversions such as photovoltaic (PV) conversion and photo-thermal conversion aims to utilize the full spectrum solar energy efficiently. A novel concentrating PV/Thermal (CPV/T) hybrid system with beam splitter and fully tracked Linear Fresnel Reflector concentrator utilizing sloped panels was proposed in this study. The relations between the structural parameters and the optical performances of the system were investigated. The concentrated radiation distribution on the PV device surface was simulated by taking into account the main optical errors and shows a good uniformity. Based on the experimental data of the components, thermodynamic analysis on the CPV/T hybrid system was carried out and the results reveal that the overall energy conversion efficiencies of the proposed CPV/T hybrid system is higher than that of the CPV system under the same conditions.

  • Thermodynamic and optical analysis for a CPV/T hybrid system with beam splitter and fully tracked Linear Fresnel Reflector concentrator utilizing sloped panels
    Solar Energy, 2014
    Co-Authors: Peng Hu, Qian Zhang, Zeshao Chen
    Abstract:

    Abstract Spectral splitting technology that separates solar spectrum into several parts and enables different energy conversions such as photovoltaic (PV) conversion and photo-thermal conversion aims to utilize the full spectrum solar energy efficiently. A novel concentrating PV/Thermal (CPV/T) hybrid system with beam splitter and fully tracked Linear Fresnel Reflector concentrator utilizing sloped panels was proposed in this study. The relations between the structural parameters and the optical performances of the system were investigated. The concentrated radiation distribution on the PV device surface was simulated by taking into account the main optical errors and shows a good uniformity. Based on the experimental data of the components, thermodynamic analysis on the CPV/T hybrid system was carried out and the results reveal that the overall energy conversion efficiencies of the proposed CPV/T hybrid system is higher than that of the CPV system under the same conditions.

Zeshao Chen - One of the best experts on this subject based on the ideXlab platform.

  • experimental and optical performances of a solar cpv device using a Linear Fresnel Reflector concentrator
    Renewable Energy, 2020
    Co-Authors: Gang Wang, Fasi Wang, Tieliu Jiang, Zeshao Chen, Fan Shen, Peng Hu
    Abstract:

    Abstract A solar CPV device using a Linear Fresnel Reflector (LFR) concentrator is described. The design principle of the concentrator is provided. The solar concentrating processes are simulated by using the MCRT approach. A small scale test rig of the concentrator is constructed to investigate the actual optical and I–V performances of the CPV device. Both of the simulation and experimental results reveal that the proposed concentrator has a relatively high solar concentrating uniformity. The configuration and optical analyses of the concentrator are launched. The results show that the geometric concentrating ratio and ground utilization ratio both increase with the solar panel installing height increased. When the solar cell height is settled, the maximum value of ground utilization ratio exists with the mirror field width increased. The sun-tracking accuracy effect analysis is also carried out. The results indicate that the normalized optical efficiency of the CPV system using the LFR concentrator can be 0.62 or higher when the tracking error is less than 1°. A solar cell monomer and a cell module are used to carry out the I–V experiments. The test results of their energy conversion efficiencies are 14.7% and 13.6%, respectively.

  • novel design and thermodynamic analysis of a solar concentration pv and thermal combined system based on compact Linear Fresnel Reflector
    Energy, 2019
    Co-Authors: Gang Wang, Fasi Wang, Zeshao Chen, Fan Shen, Peng Hu
    Abstract:

    Abstract A novel solar concentration photovoltaic (PV) and thermal combined system based on compact Linear Fresnel Reflector (CLFR) concentrator is proposed. The configuration and structural design approach of the PV and thermal combined system are introduced. The spectral beam splitter is designed by using the Needle optimization approach. Solar concentrating processes are simulated and relevant results show a high solar concentrating uniformity provided by the proposed combined system. The investigations of optical performance and relevant influential factors reveal that there is an optimal solar panel installation height for the proposed combined system when the slope angle and width of solar cells are settled. The effect of sun tracking error on the optical performance is also studied. The energy conversion analysis is carried out and the results show that the PV and thermal combined system has higher PV conversion and overall energy efficiencies in comparison with the solar concentration PV system without beam splitter. Furthermore, the effect of solar thermal collector temperature is investigated and the results reveal that there is an optimal tube collector operating temperature which can lead to the maximum total output power and overall energy efficiency.

  • thermodynamic and optical analysis for a cpv t hybrid system with beam splitter and fully tracked Linear Fresnel Reflector concentrator utilizing sloped panels
    Solar Energy, 2014
    Co-Authors: Peng Hu, Qian Zhang, Zeshao Chen
    Abstract:

    Abstract Spectral splitting technology that separates solar spectrum into several parts and enables different energy conversions such as photovoltaic (PV) conversion and photo-thermal conversion aims to utilize the full spectrum solar energy efficiently. A novel concentrating PV/Thermal (CPV/T) hybrid system with beam splitter and fully tracked Linear Fresnel Reflector concentrator utilizing sloped panels was proposed in this study. The relations between the structural parameters and the optical performances of the system were investigated. The concentrated radiation distribution on the PV device surface was simulated by taking into account the main optical errors and shows a good uniformity. Based on the experimental data of the components, thermodynamic analysis on the CPV/T hybrid system was carried out and the results reveal that the overall energy conversion efficiencies of the proposed CPV/T hybrid system is higher than that of the CPV system under the same conditions.

  • Thermodynamic and optical analysis for a CPV/T hybrid system with beam splitter and fully tracked Linear Fresnel Reflector concentrator utilizing sloped panels
    Solar Energy, 2014
    Co-Authors: Peng Hu, Qian Zhang, Zeshao Chen
    Abstract:

    Abstract Spectral splitting technology that separates solar spectrum into several parts and enables different energy conversions such as photovoltaic (PV) conversion and photo-thermal conversion aims to utilize the full spectrum solar energy efficiently. A novel concentrating PV/Thermal (CPV/T) hybrid system with beam splitter and fully tracked Linear Fresnel Reflector concentrator utilizing sloped panels was proposed in this study. The relations between the structural parameters and the optical performances of the system were investigated. The concentrated radiation distribution on the PV device surface was simulated by taking into account the main optical errors and shows a good uniformity. Based on the experimental data of the components, thermodynamic analysis on the CPV/T hybrid system was carried out and the results reveal that the overall energy conversion efficiencies of the proposed CPV/T hybrid system is higher than that of the CPV system under the same conditions.