How to Construct a Combined S-CO2 Cycle for Coal Fired Power Plant?
It is difficult to recover the residual heat from flue gas when supercritical carbon dioxide (S-CO2) cycle is used for a coal fired power plant, due to the higher CO2 temperature in tail flue and the limited air temperature in air preheater. The combined cycle is helpful for residual heat recovery....
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| Format: | Article |
| Language: | English |
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MDPI AG
2018-12-01
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| Series: | Entropy |
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| Online Access: | http://www.mdpi.com/1099-4300/21/1/19 |
| _version_ | 1828114782363844608 |
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| author | Enhui Sun Han Hu Hangning Li Chao Liu Jinliang Xu |
| author_facet | Enhui Sun Han Hu Hangning Li Chao Liu Jinliang Xu |
| author_sort | Enhui Sun |
| collection | DOAJ |
| description | It is difficult to recover the residual heat from flue gas when supercritical carbon dioxide (S-CO2) cycle is used for a coal fired power plant, due to the higher CO2 temperature in tail flue and the limited air temperature in air preheater. The combined cycle is helpful for residual heat recovery. Thus, it is important to build an efficient bottom cycle. In this paper, we proposed a novel exergy destruction control strategy during residual heat recovery to equal and minimize the exergy destruction for different bottom cycles. Five bottom cycles are analyzed to identify their differences in thermal efficiencies (ηth,b), and the CO2 temperature entering the bottom cycle heater (T4b) etc. We show that the exergy destruction can be minimized by a suitable pinch temperature between flue gas and CO2 in the heater via adjusting T4b. Among the five bottom cycles, either the recompression cycle (RC) or the partial cooling cycle (PACC) exhibits good performance. The power generation efficiency is 47.04% when the vapor parameters of CO2 are 620/30 MPa, with the double-reheating-recompression cycle as the top cycle, and RC as the bottom cycle. Such efficiency is higher than that of the supercritical water cycle power plant. |
| first_indexed | 2024-04-11T12:30:22Z |
| format | Article |
| id | doaj.art-99da277806a8487d855f06b6cee7d1db |
| institution | Directory Open Access Journal |
| issn | 1099-4300 |
| language | English |
| last_indexed | 2024-04-11T12:30:22Z |
| publishDate | 2018-12-01 |
| publisher | MDPI AG |
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| series | Entropy |
| spelling | doaj.art-99da277806a8487d855f06b6cee7d1db2022-12-22T04:23:46ZengMDPI AGEntropy1099-43002018-12-012111910.3390/e21010019e21010019How to Construct a Combined S-CO2 Cycle for Coal Fired Power Plant?Enhui Sun0Han Hu1Hangning Li2Chao Liu3Jinliang Xu4Beijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy Utilization, North China Electric Power University, Beijing 102206, ChinaBeijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy Utilization, North China Electric Power University, Beijing 102206, ChinaBeijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy Utilization, North China Electric Power University, Beijing 102206, ChinaBeijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy Utilization, North China Electric Power University, Beijing 102206, ChinaBeijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy Utilization, North China Electric Power University, Beijing 102206, ChinaIt is difficult to recover the residual heat from flue gas when supercritical carbon dioxide (S-CO2) cycle is used for a coal fired power plant, due to the higher CO2 temperature in tail flue and the limited air temperature in air preheater. The combined cycle is helpful for residual heat recovery. Thus, it is important to build an efficient bottom cycle. In this paper, we proposed a novel exergy destruction control strategy during residual heat recovery to equal and minimize the exergy destruction for different bottom cycles. Five bottom cycles are analyzed to identify their differences in thermal efficiencies (ηth,b), and the CO2 temperature entering the bottom cycle heater (T4b) etc. We show that the exergy destruction can be minimized by a suitable pinch temperature between flue gas and CO2 in the heater via adjusting T4b. Among the five bottom cycles, either the recompression cycle (RC) or the partial cooling cycle (PACC) exhibits good performance. The power generation efficiency is 47.04% when the vapor parameters of CO2 are 620/30 MPa, with the double-reheating-recompression cycle as the top cycle, and RC as the bottom cycle. Such efficiency is higher than that of the supercritical water cycle power plant.http://www.mdpi.com/1099-4300/21/1/19S-CO2 coal fired power plantcombined cyclethermodynamicsexergy destructionresidual heat of flue gas |
| spellingShingle | Enhui Sun Han Hu Hangning Li Chao Liu Jinliang Xu How to Construct a Combined S-CO2 Cycle for Coal Fired Power Plant? Entropy S-CO2 coal fired power plant combined cycle thermodynamics exergy destruction residual heat of flue gas |
| title | How to Construct a Combined S-CO2 Cycle for Coal Fired Power Plant? |
| title_full | How to Construct a Combined S-CO2 Cycle for Coal Fired Power Plant? |
| title_fullStr | How to Construct a Combined S-CO2 Cycle for Coal Fired Power Plant? |
| title_full_unstemmed | How to Construct a Combined S-CO2 Cycle for Coal Fired Power Plant? |
| title_short | How to Construct a Combined S-CO2 Cycle for Coal Fired Power Plant? |
| title_sort | how to construct a combined s co2 cycle for coal fired power plant |
| topic | S-CO2 coal fired power plant combined cycle thermodynamics exergy destruction residual heat of flue gas |
| url | http://www.mdpi.com/1099-4300/21/1/19 |
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