The Experts below are selected from a list of 48408 Experts worldwide ranked by ideXlab platform
Ahmed M Daabo - One of the best experts on this subject based on the ideXlab platform.
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modelling and parametric analysis of small scale axial and radial outflow Turbines for organic rankine cycle applications
Applied Energy, 2017Co-Authors: Raya Aldadah, Ayad Al Jubori, Saad Mahmoud, Ahmed M DaaboAbstract:The existing literature pays limited attention to the design and 3D analysis of small-scale axial and radial–outflow Turbines that can be utilised in Organic Rankine Cycles (ORC) for power generation with a low–temperature (<100°C) heat source and low mass flow rate. Turbine Efficiency significantly affects an ORC’s Efficiency because the Turbine is considered a key component of the ORC. Therefore, obtaining high cycle thermal Efficiency requires high Turbine Efficiency and power output. This work presents an integrated mathematical model for developing efficient axial and radial-outflow (centrifugal) Turbines using a range of organic working fluids (R141b, R245fa, R365mfc, isobutane and n–pentane). This mathematical approach integrates mean-line design and 3D CFD analysis with ORC modelling. The ANSYSR17CFX is used to predict 3D viscous flow and Turbine performance. To achieve accurate prediction, the ORC/Turbines model uses real gas formulations based on the REFPROP database. The results showed that the axial Turbine performed better, with Efficiency of 82.5% and power output of 15.15kW, compared with 79.05% and 13.625kW from the radial–outflow Turbine, with n-pentane as the working fluid in both cases. The maximum cycle thermal Efficiency was 11.74% and 10.25% for axial and radial-outflow Turbines respectively with n-pentane as the working fluid and a heat source temperature of 87°C. The large tip diameter of the axial Turbine was 73.82mm compared with 108.72mm for the radial-outflow Turbine. The predicted results are better than others in the literature and highlight the advantages of the integrated approach for accurate prediction of ORC performance based on small-scale axial and radial-outflow Turbines.
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modelling and parametric analysis of small scale axial and radial outflow Turbines for organic rankine cycle applications
Applied Energy, 2017Co-Authors: Raya Aldadah, Ayad Al Jubori, Saad Mahmoud, Ahmed M DaaboAbstract:The existing literature pays limited attention to the design and 3D analysis of small-scale axial and radial–outflow Turbines that can be utilised in Organic Rankine Cycles (ORC) for power generation with a low–temperature (<100°C) heat source and low mass flow rate. Turbine Efficiency significantly affects an ORC’s Efficiency because the Turbine is considered a key component of the ORC. Therefore, obtaining high cycle thermal Efficiency requires high Turbine Efficiency and power output. This work presents an integrated mathematical model for developing efficient axial and radial-outflow (centrifugal) Turbines using a range of organic working fluids (R141b, R245fa, R365mfc, isobutane and n–pentane). This mathematical approach integrates mean-line design and 3D CFD analysis with ORC modelling. The ANSYSR17CFX is used to predict 3D viscous flow and Turbine performance. To achieve accurate prediction, the ORC/Turbines model uses real gas formulations based on the REFPROP database. The results showed that the axial Turbine performed better, with Efficiency of 82.5% and power output of 15.15kW, compared with 79.05% and 13.625kW from the radial–outflow Turbine, with n-pentane as the working fluid in both cases. The maximum cycle thermal Efficiency was 11.74% and 10.25% for axial and radial-outflow Turbines respectively with n-pentane as the working fluid and a heat source temperature of 87°C. The large tip diameter of the axial Turbine was 73.82mm compared with 108.72mm for the radial-outflow Turbine. The predicted results are better than others in the literature and highlight the advantages of the integrated approach for accurate prediction of ORC performance based on small-scale axial and radial-outflow Turbines.
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development of three dimensional optimization of a small scale radial Turbine for solar powered brayton cycle application
Applied Thermal Engineering, 2017Co-Authors: Ahmed M Daabo, Ayad Al Jubori, Saad Mahmoud, Raya AldadahAbstract:Abstract Numerical simulation was carried out to optimize the design of a small-scale radial Turbine. One-dimensional (1D) Mean Line (ML) approach and three-dimensional computational fluid dynamic (3D CFD) simulations, using 3D Reynolds-Averaged Navier-Stokes (RANS) models with the shear stress transport (SST) turbulence model in ANSYS®15-CFX, were employed to achieve the best Turbine performance and consequently cycle Efficiency. For the current study, a new methodology that integrates the Brayton cycle analysis with modelling of a highly efficient small-scale radial Turbine at a wide range of inlet temperatures was developed. A multi-objective function was utilized for optimizing the designed radial Turbine power in the range of 1.5–7.5 kW. This method has been developed in order to find the optimum design, from an aerodynamic point of view. After applying a well-designed range of parameters for both the stator and the rotor, the results demonstrated an excellent improvement in the Turbine Efficiency from 82.3% to 89.7% for the same range of output power. Moreover, the effect of the Turbine inlet temperature, rotational speed and pressure ratio was further studied and presented in this paper. Finally, the overall cycle Efficiency showed an excellent improvement of about 6.5% for the current boundary conditions; and it yielded more than 10% with the increase in the inlet temperature and the pressure ratio. Such results highlight the potential and the benefits of the suggested methodology to achieve a high performance (i.e. Turbine Efficiency and cycle Efficiency).
Ayad Al Jubori - One of the best experts on this subject based on the ideXlab platform.
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modelling and parametric analysis of small scale axial and radial outflow Turbines for organic rankine cycle applications
Applied Energy, 2017Co-Authors: Raya Aldadah, Ayad Al Jubori, Saad Mahmoud, Ahmed M DaaboAbstract:The existing literature pays limited attention to the design and 3D analysis of small-scale axial and radial–outflow Turbines that can be utilised in Organic Rankine Cycles (ORC) for power generation with a low–temperature (<100°C) heat source and low mass flow rate. Turbine Efficiency significantly affects an ORC’s Efficiency because the Turbine is considered a key component of the ORC. Therefore, obtaining high cycle thermal Efficiency requires high Turbine Efficiency and power output. This work presents an integrated mathematical model for developing efficient axial and radial-outflow (centrifugal) Turbines using a range of organic working fluids (R141b, R245fa, R365mfc, isobutane and n–pentane). This mathematical approach integrates mean-line design and 3D CFD analysis with ORC modelling. The ANSYSR17CFX is used to predict 3D viscous flow and Turbine performance. To achieve accurate prediction, the ORC/Turbines model uses real gas formulations based on the REFPROP database. The results showed that the axial Turbine performed better, with Efficiency of 82.5% and power output of 15.15kW, compared with 79.05% and 13.625kW from the radial–outflow Turbine, with n-pentane as the working fluid in both cases. The maximum cycle thermal Efficiency was 11.74% and 10.25% for axial and radial-outflow Turbines respectively with n-pentane as the working fluid and a heat source temperature of 87°C. The large tip diameter of the axial Turbine was 73.82mm compared with 108.72mm for the radial-outflow Turbine. The predicted results are better than others in the literature and highlight the advantages of the integrated approach for accurate prediction of ORC performance based on small-scale axial and radial-outflow Turbines.
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modelling and parametric analysis of small scale axial and radial outflow Turbines for organic rankine cycle applications
Applied Energy, 2017Co-Authors: Raya Aldadah, Ayad Al Jubori, Saad Mahmoud, Ahmed M DaaboAbstract:The existing literature pays limited attention to the design and 3D analysis of small-scale axial and radial–outflow Turbines that can be utilised in Organic Rankine Cycles (ORC) for power generation with a low–temperature (<100°C) heat source and low mass flow rate. Turbine Efficiency significantly affects an ORC’s Efficiency because the Turbine is considered a key component of the ORC. Therefore, obtaining high cycle thermal Efficiency requires high Turbine Efficiency and power output. This work presents an integrated mathematical model for developing efficient axial and radial-outflow (centrifugal) Turbines using a range of organic working fluids (R141b, R245fa, R365mfc, isobutane and n–pentane). This mathematical approach integrates mean-line design and 3D CFD analysis with ORC modelling. The ANSYSR17CFX is used to predict 3D viscous flow and Turbine performance. To achieve accurate prediction, the ORC/Turbines model uses real gas formulations based on the REFPROP database. The results showed that the axial Turbine performed better, with Efficiency of 82.5% and power output of 15.15kW, compared with 79.05% and 13.625kW from the radial–outflow Turbine, with n-pentane as the working fluid in both cases. The maximum cycle thermal Efficiency was 11.74% and 10.25% for axial and radial-outflow Turbines respectively with n-pentane as the working fluid and a heat source temperature of 87°C. The large tip diameter of the axial Turbine was 73.82mm compared with 108.72mm for the radial-outflow Turbine. The predicted results are better than others in the literature and highlight the advantages of the integrated approach for accurate prediction of ORC performance based on small-scale axial and radial-outflow Turbines.
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development of three dimensional optimization of a small scale radial Turbine for solar powered brayton cycle application
Applied Thermal Engineering, 2017Co-Authors: Ahmed M Daabo, Ayad Al Jubori, Saad Mahmoud, Raya AldadahAbstract:Abstract Numerical simulation was carried out to optimize the design of a small-scale radial Turbine. One-dimensional (1D) Mean Line (ML) approach and three-dimensional computational fluid dynamic (3D CFD) simulations, using 3D Reynolds-Averaged Navier-Stokes (RANS) models with the shear stress transport (SST) turbulence model in ANSYS®15-CFX, were employed to achieve the best Turbine performance and consequently cycle Efficiency. For the current study, a new methodology that integrates the Brayton cycle analysis with modelling of a highly efficient small-scale radial Turbine at a wide range of inlet temperatures was developed. A multi-objective function was utilized for optimizing the designed radial Turbine power in the range of 1.5–7.5 kW. This method has been developed in order to find the optimum design, from an aerodynamic point of view. After applying a well-designed range of parameters for both the stator and the rotor, the results demonstrated an excellent improvement in the Turbine Efficiency from 82.3% to 89.7% for the same range of output power. Moreover, the effect of the Turbine inlet temperature, rotational speed and pressure ratio was further studied and presented in this paper. Finally, the overall cycle Efficiency showed an excellent improvement of about 6.5% for the current boundary conditions; and it yielded more than 10% with the increase in the inlet temperature and the pressure ratio. Such results highlight the potential and the benefits of the suggested methodology to achieve a high performance (i.e. Turbine Efficiency and cycle Efficiency).
Bayu Prabowo - One of the best experts on this subject based on the ideXlab platform.
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co2 recycling biomass gasification system for highly efficient and carbon negative power generation
Applied Energy, 2015Co-Authors: Bayu Prabowo, Muhammad Aziz, Herri Susanto, Kentaro Umeki, Kunio YoshikawaAbstract:This study explored the feasibility of biomass CO2 gasification as an effective method for implementing the concept of a carbon-negative power system through bioenergy with carbon capturing and storage. A CO2-recycling biomass gasification system was developed and examined using the thermal equilibrium model. Sensitivity analysis was performed by varying the gasifier temperature from 750 to 950°C, and the Turbine inlet temperature (TIT) and Turbine exit temperature (TET) of the gas Turbine from 1000 to 1200°C and from 900 to 1000°C, respectively. The gasifier Efficiency was increased by an increase in the CO2 recycling ratio with the more significant trend shown at the lower gasifier temperature. The Turbine Efficiency decreased as the CO2 recycling ratio to the gasifier increased over a certain limit, a ratio of 0.55 in most cases. A pressure ratio of 2.3 was optimum in terms of Turbine Efficiency. Under the examined conditions, the optimum conditions for gaining the highest system Efficiency, 39.03%, were a recycling ratio of 0.55 and a TET and TIT of 1000 and 1200°C respectively. The proposed system had 7.57% higher Efficiency and exhausted 299.15g CO2/kWh less CO2 emissions than conventional air gasification. Combined with carbon capturing and storage, the system potentially generates carbon-negative power generation with intensity of around 1.55-kgCO2/kgwet-biomass and a maximum Efficiency penalty of 6.89%.
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co2 recycling biomass gasification system for highly efficient and carbon negative power generation
Applied Energy, 2015Co-Authors: Bayu Prabowo, Muhammad Aziz, Herri Susanto, Kentaro Umeki, Kunio YoshikawaAbstract:This study explored the feasibility of biomass CO2 gasification as an effective method for implementing the concept of a carbon-negative power system through bioenergy with carbon capturing and storage. A CO2-recycling biomass gasification system was developed and examined using the thermal equilibrium model. Sensitivity analysis was performed by varying the gasifier temperature from 750 to 950°C, and the Turbine inlet temperature (TIT) and Turbine exit temperature (TET) of the gas Turbine from 1000 to 1200°C and from 900 to 1000°C, respectively. The gasifier Efficiency was increased by an increase in the CO2 recycling ratio with the more significant trend shown at the lower gasifier temperature. The Turbine Efficiency decreased as the CO2 recycling ratio to the gasifier increased over a certain limit, a ratio of 0.55 in most cases. A pressure ratio of 2.3 was optimum in terms of Turbine Efficiency. Under the examined conditions, the optimum conditions for gaining the highest system Efficiency, 39.03%, were a recycling ratio of 0.55 and a TET and TIT of 1000 and 1200°C respectively. The proposed system had 7.57% higher Efficiency and exhausted 299.15g CO2/kWh less CO2 emissions than conventional air gasification. Combined with carbon capturing and storage, the system potentially generates carbon-negative power generation with intensity of around 1.55-kgCO2/kgwet-biomass and a maximum Efficiency penalty of 6.89%.
Raya Aldadah - One of the best experts on this subject based on the ideXlab platform.
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development and experimental study of a small scale compressed air radial inflow Turbine for distributed power generation
Applied Thermal Engineering, 2017Co-Authors: Kiyarash Rahbar, Raya Aldadah, Saad Mahmoud, Nima Moazami, Seyed MirhadizadehAbstract:Abstract With ever increasing demand on energy, disturbed power generation utilizing efficient technologies such as compressed air energy storage (CAES) and organic Rankine cycle (ORC) are receiving growing attention. Expander for such systems is a key component and its performance has substantial effects on overall system Efficiency. This study addresses such component by proposing an effective and comprehensive methodology for developing a small-scale radial inflow Turbine (RIT). The methodology consists of 1-D modelling, 3-D aerodynamic investigation and structural analysis, manufacturing with pioneering technique and experimental testing for validation. The proposed 1-D modelling was very effective in determining the primary geometry and performance of Turbine based on parametric studies of Turbine input design variables. However with CFD analysis, it was shown that more efficient Turbine geometry can be achieved that not only provides more realistic Turbine performance by capturing the 3-D fluid flow behaviour but also improves Turbine Efficiency with the aid of parametric studies of Turbine geometry parameters. Turbine Efficiency was improved from 81.3% obtained from 1-D modelling to 84.5% obtained by CFD. Accuracy of the CFD model was assessed by conducting experiments on the RIT manufactured with stereolithography technique. The CFD model can predict Turbine Efficiency and power with accuracy of ±16% and ±13% respectively for a wide range of tested operating conditions. Such results highlights the effectiveness of the proposed methodology and the CFD model can be used as benchmarking model for analyses of small-scale RITs. Besides, it was shown that for such applications, the novel manufacturing technique and employed material are very effective for producing prototypes that assist design decisions and validation of CFD model with reasonable accuracy at reasonable cost and in timely manner.
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modelling and parametric analysis of small scale axial and radial outflow Turbines for organic rankine cycle applications
Applied Energy, 2017Co-Authors: Raya Aldadah, Ayad Al Jubori, Saad Mahmoud, Ahmed M DaaboAbstract:The existing literature pays limited attention to the design and 3D analysis of small-scale axial and radial–outflow Turbines that can be utilised in Organic Rankine Cycles (ORC) for power generation with a low–temperature (<100°C) heat source and low mass flow rate. Turbine Efficiency significantly affects an ORC’s Efficiency because the Turbine is considered a key component of the ORC. Therefore, obtaining high cycle thermal Efficiency requires high Turbine Efficiency and power output. This work presents an integrated mathematical model for developing efficient axial and radial-outflow (centrifugal) Turbines using a range of organic working fluids (R141b, R245fa, R365mfc, isobutane and n–pentane). This mathematical approach integrates mean-line design and 3D CFD analysis with ORC modelling. The ANSYSR17CFX is used to predict 3D viscous flow and Turbine performance. To achieve accurate prediction, the ORC/Turbines model uses real gas formulations based on the REFPROP database. The results showed that the axial Turbine performed better, with Efficiency of 82.5% and power output of 15.15kW, compared with 79.05% and 13.625kW from the radial–outflow Turbine, with n-pentane as the working fluid in both cases. The maximum cycle thermal Efficiency was 11.74% and 10.25% for axial and radial-outflow Turbines respectively with n-pentane as the working fluid and a heat source temperature of 87°C. The large tip diameter of the axial Turbine was 73.82mm compared with 108.72mm for the radial-outflow Turbine. The predicted results are better than others in the literature and highlight the advantages of the integrated approach for accurate prediction of ORC performance based on small-scale axial and radial-outflow Turbines.
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modelling and parametric analysis of small scale axial and radial outflow Turbines for organic rankine cycle applications
Applied Energy, 2017Co-Authors: Raya Aldadah, Ayad Al Jubori, Saad Mahmoud, Ahmed M DaaboAbstract:The existing literature pays limited attention to the design and 3D analysis of small-scale axial and radial–outflow Turbines that can be utilised in Organic Rankine Cycles (ORC) for power generation with a low–temperature (<100°C) heat source and low mass flow rate. Turbine Efficiency significantly affects an ORC’s Efficiency because the Turbine is considered a key component of the ORC. Therefore, obtaining high cycle thermal Efficiency requires high Turbine Efficiency and power output. This work presents an integrated mathematical model for developing efficient axial and radial-outflow (centrifugal) Turbines using a range of organic working fluids (R141b, R245fa, R365mfc, isobutane and n–pentane). This mathematical approach integrates mean-line design and 3D CFD analysis with ORC modelling. The ANSYSR17CFX is used to predict 3D viscous flow and Turbine performance. To achieve accurate prediction, the ORC/Turbines model uses real gas formulations based on the REFPROP database. The results showed that the axial Turbine performed better, with Efficiency of 82.5% and power output of 15.15kW, compared with 79.05% and 13.625kW from the radial–outflow Turbine, with n-pentane as the working fluid in both cases. The maximum cycle thermal Efficiency was 11.74% and 10.25% for axial and radial-outflow Turbines respectively with n-pentane as the working fluid and a heat source temperature of 87°C. The large tip diameter of the axial Turbine was 73.82mm compared with 108.72mm for the radial-outflow Turbine. The predicted results are better than others in the literature and highlight the advantages of the integrated approach for accurate prediction of ORC performance based on small-scale axial and radial-outflow Turbines.
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development of three dimensional optimization of a small scale radial Turbine for solar powered brayton cycle application
Applied Thermal Engineering, 2017Co-Authors: Ahmed M Daabo, Ayad Al Jubori, Saad Mahmoud, Raya AldadahAbstract:Abstract Numerical simulation was carried out to optimize the design of a small-scale radial Turbine. One-dimensional (1D) Mean Line (ML) approach and three-dimensional computational fluid dynamic (3D CFD) simulations, using 3D Reynolds-Averaged Navier-Stokes (RANS) models with the shear stress transport (SST) turbulence model in ANSYS®15-CFX, were employed to achieve the best Turbine performance and consequently cycle Efficiency. For the current study, a new methodology that integrates the Brayton cycle analysis with modelling of a highly efficient small-scale radial Turbine at a wide range of inlet temperatures was developed. A multi-objective function was utilized for optimizing the designed radial Turbine power in the range of 1.5–7.5 kW. This method has been developed in order to find the optimum design, from an aerodynamic point of view. After applying a well-designed range of parameters for both the stator and the rotor, the results demonstrated an excellent improvement in the Turbine Efficiency from 82.3% to 89.7% for the same range of output power. Moreover, the effect of the Turbine inlet temperature, rotational speed and pressure ratio was further studied and presented in this paper. Finally, the overall cycle Efficiency showed an excellent improvement of about 6.5% for the current boundary conditions; and it yielded more than 10% with the increase in the inlet temperature and the pressure ratio. Such results highlight the potential and the benefits of the suggested methodology to achieve a high performance (i.e. Turbine Efficiency and cycle Efficiency).
Kunio Yoshikawa - One of the best experts on this subject based on the ideXlab platform.
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co2 recycling biomass gasification system for highly efficient and carbon negative power generation
Applied Energy, 2015Co-Authors: Bayu Prabowo, Muhammad Aziz, Herri Susanto, Kentaro Umeki, Kunio YoshikawaAbstract:This study explored the feasibility of biomass CO2 gasification as an effective method for implementing the concept of a carbon-negative power system through bioenergy with carbon capturing and storage. A CO2-recycling biomass gasification system was developed and examined using the thermal equilibrium model. Sensitivity analysis was performed by varying the gasifier temperature from 750 to 950°C, and the Turbine inlet temperature (TIT) and Turbine exit temperature (TET) of the gas Turbine from 1000 to 1200°C and from 900 to 1000°C, respectively. The gasifier Efficiency was increased by an increase in the CO2 recycling ratio with the more significant trend shown at the lower gasifier temperature. The Turbine Efficiency decreased as the CO2 recycling ratio to the gasifier increased over a certain limit, a ratio of 0.55 in most cases. A pressure ratio of 2.3 was optimum in terms of Turbine Efficiency. Under the examined conditions, the optimum conditions for gaining the highest system Efficiency, 39.03%, were a recycling ratio of 0.55 and a TET and TIT of 1000 and 1200°C respectively. The proposed system had 7.57% higher Efficiency and exhausted 299.15g CO2/kWh less CO2 emissions than conventional air gasification. Combined with carbon capturing and storage, the system potentially generates carbon-negative power generation with intensity of around 1.55-kgCO2/kgwet-biomass and a maximum Efficiency penalty of 6.89%.
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co2 recycling biomass gasification system for highly efficient and carbon negative power generation
Applied Energy, 2015Co-Authors: Bayu Prabowo, Muhammad Aziz, Herri Susanto, Kentaro Umeki, Kunio YoshikawaAbstract:This study explored the feasibility of biomass CO2 gasification as an effective method for implementing the concept of a carbon-negative power system through bioenergy with carbon capturing and storage. A CO2-recycling biomass gasification system was developed and examined using the thermal equilibrium model. Sensitivity analysis was performed by varying the gasifier temperature from 750 to 950°C, and the Turbine inlet temperature (TIT) and Turbine exit temperature (TET) of the gas Turbine from 1000 to 1200°C and from 900 to 1000°C, respectively. The gasifier Efficiency was increased by an increase in the CO2 recycling ratio with the more significant trend shown at the lower gasifier temperature. The Turbine Efficiency decreased as the CO2 recycling ratio to the gasifier increased over a certain limit, a ratio of 0.55 in most cases. A pressure ratio of 2.3 was optimum in terms of Turbine Efficiency. Under the examined conditions, the optimum conditions for gaining the highest system Efficiency, 39.03%, were a recycling ratio of 0.55 and a TET and TIT of 1000 and 1200°C respectively. The proposed system had 7.57% higher Efficiency and exhausted 299.15g CO2/kWh less CO2 emissions than conventional air gasification. Combined with carbon capturing and storage, the system potentially generates carbon-negative power generation with intensity of around 1.55-kgCO2/kgwet-biomass and a maximum Efficiency penalty of 6.89%.
