Novel analysis of second law and irreversibility for a solar power plant using heliostat field and molten salt
Abstract Nowadays, the low efficiency of solar energy power plant systems brings about uneconomical performance and high‐cost uncompetitive industries compared with the traditional fossil fuel ones. In order to overcome these kinds of issues, in this study, the performance of a solar tower coupled w...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2020-11-01
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| Series: | Energy Science & Engineering |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/ese3.802 |
| _version_ | 1811293361044193280 |
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| author | Mohammad Hossein Zolfagharnasab Cyrus Aghanajafi Soheil Kavian Niloufar Heydarian Mohammad Hossein Ahmadi |
| author_facet | Mohammad Hossein Zolfagharnasab Cyrus Aghanajafi Soheil Kavian Niloufar Heydarian Mohammad Hossein Ahmadi |
| author_sort | Mohammad Hossein Zolfagharnasab |
| collection | DOAJ |
| description | Abstract Nowadays, the low efficiency of solar energy power plant systems brings about uneconomical performance and high‐cost uncompetitive industries compared with the traditional fossil fuel ones. In order to overcome these kinds of issues, in this study, the performance of a solar tower coupled with a Rankine cycle is scrutinized using the first and second laws of thermodynamic. Moreover, a numerical code has been developed in the GNU Octave software environment to calculate the precise value for both energy and exergy losses of each component. Furthermore, the sensitivity analysis approach corresponds to the variation of several inner parameters such as direct normal irradiation (DNI), molten salt outlet temperature (MSOT), and the molten salt velocity (MSV), environmental parameters such as wind speed and ambient temperature have been performed. In addition, the overall losses are calculated by considering all possible forms of losses such as convection, conduction, reflection, and emission, and also, the portion of each source of these losses are determined. The obtained results indicate that the maximum exergy loss occurs in the central receiver system (CRS), while the major energy loss occurs in the turbine located in the power block. The sensitivity analysis shows that the rise of DNI significantly increases the exergy%energy efficiency of the cycle and also, the portion of loss related to emission heat transfer would be enhanced. Moreover, the variation of the MSV and MSOT illustrate influencing the performance of the cycle; consequently, the MSOT changes demonstrate a reverse relation with energy and direct relation with exergy efficiency. Accordingly, an optimum value of 650K is calculated for the MSOT as well as an optimum value of 2 m%s for the MSV. The environmental sensitivity analysis indicates that the enhancement of wind speed and ambient temperature has a negative impact on the net output of the cycle, which is not desirable. |
| first_indexed | 2024-04-13T05:00:14Z |
| format | Article |
| id | doaj.art-e1cde029a0b845619c6b679fa7a227b5 |
| institution | Directory Open Access Journal |
| issn | 2050-0505 |
| language | English |
| last_indexed | 2024-04-13T05:00:14Z |
| publishDate | 2020-11-01 |
| publisher | Wiley |
| record_format | Article |
| series | Energy Science & Engineering |
| spelling | doaj.art-e1cde029a0b845619c6b679fa7a227b52022-12-22T03:01:22ZengWileyEnergy Science & Engineering2050-05052020-11-018114136415310.1002/ese3.802Novel analysis of second law and irreversibility for a solar power plant using heliostat field and molten saltMohammad Hossein Zolfagharnasab0Cyrus Aghanajafi1Soheil Kavian2Niloufar Heydarian3Mohammad Hossein Ahmadi4Faculty of Mechanical Engineering K. N. Toosi University of Technology Tehran IranFaculty of Mechanical Engineering K. N. Toosi University of Technology Tehran IranDepartment of Mechanical Engineering, Science and Research Branch Islamic Azad University Tehran IranFaculty of Mechanical Engineering K. N. Toosi University of Technology Tehran IranFaculty of Mechanical Engineering Shahrood University of Technology Shahrood IranAbstract Nowadays, the low efficiency of solar energy power plant systems brings about uneconomical performance and high‐cost uncompetitive industries compared with the traditional fossil fuel ones. In order to overcome these kinds of issues, in this study, the performance of a solar tower coupled with a Rankine cycle is scrutinized using the first and second laws of thermodynamic. Moreover, a numerical code has been developed in the GNU Octave software environment to calculate the precise value for both energy and exergy losses of each component. Furthermore, the sensitivity analysis approach corresponds to the variation of several inner parameters such as direct normal irradiation (DNI), molten salt outlet temperature (MSOT), and the molten salt velocity (MSV), environmental parameters such as wind speed and ambient temperature have been performed. In addition, the overall losses are calculated by considering all possible forms of losses such as convection, conduction, reflection, and emission, and also, the portion of each source of these losses are determined. The obtained results indicate that the maximum exergy loss occurs in the central receiver system (CRS), while the major energy loss occurs in the turbine located in the power block. The sensitivity analysis shows that the rise of DNI significantly increases the exergy%energy efficiency of the cycle and also, the portion of loss related to emission heat transfer would be enhanced. Moreover, the variation of the MSV and MSOT illustrate influencing the performance of the cycle; consequently, the MSOT changes demonstrate a reverse relation with energy and direct relation with exergy efficiency. Accordingly, an optimum value of 650K is calculated for the MSOT as well as an optimum value of 2 m%s for the MSV. The environmental sensitivity analysis indicates that the enhancement of wind speed and ambient temperature has a negative impact on the net output of the cycle, which is not desirable.https://doi.org/10.1002/ese3.802energy lossexergy lossheliostat fieldmolten saltsolar power tower plant |
| spellingShingle | Mohammad Hossein Zolfagharnasab Cyrus Aghanajafi Soheil Kavian Niloufar Heydarian Mohammad Hossein Ahmadi Novel analysis of second law and irreversibility for a solar power plant using heliostat field and molten salt Energy Science & Engineering energy loss exergy loss heliostat field molten salt solar power tower plant |
| title | Novel analysis of second law and irreversibility for a solar power plant using heliostat field and molten salt |
| title_full | Novel analysis of second law and irreversibility for a solar power plant using heliostat field and molten salt |
| title_fullStr | Novel analysis of second law and irreversibility for a solar power plant using heliostat field and molten salt |
| title_full_unstemmed | Novel analysis of second law and irreversibility for a solar power plant using heliostat field and molten salt |
| title_short | Novel analysis of second law and irreversibility for a solar power plant using heliostat field and molten salt |
| title_sort | novel analysis of second law and irreversibility for a solar power plant using heliostat field and molten salt |
| topic | energy loss exergy loss heliostat field molten salt solar power tower plant |
| url | https://doi.org/10.1002/ese3.802 |
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