Research on the Modification of Coal Adaptability and Carbon Emissions Reduction Technology for Coal-Fired Boilers
In order to solve the problems of the high temperature of flue gas, low boiler efficiency, and the high concentration of nitrogen oxide (NOx) emissions for a 330 MW boiler fired with lean coal in a power plant, an adaptation modification by using different type of coals in the power generation unit...
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MDPI AG
2022-12-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/15/24/9533 |
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| author | Dan Peng Ben Wang Xingfei Cai Lei Bei |
| author_facet | Dan Peng Ben Wang Xingfei Cai Lei Bei |
| author_sort | Dan Peng |
| collection | DOAJ |
| description | In order to solve the problems of the high temperature of flue gas, low boiler efficiency, and the high concentration of nitrogen oxide (NOx) emissions for a 330 MW boiler fired with lean coal in a power plant, an adaptation modification by using different type of coals in the power generation unit (including pulverizing system, burners, heating surface, and so on) was carried out. The performances of boilers were tested under different combustion conditions before and after the modification. The results of the test show that the volatile content is higher and easy to burn out, and the combustible content of fly ash and slag are greatly reduced after the change in coal type (while lean coal is changed into bituminous coal). At the same time, the low-temperature economizer can greatly reduce the flue gas temperature, thus increasing the efficiency from 90.36% (lean coal, corrected) to 92.71% (bituminous coal). After the change in coal type (lean coal to bituminous coal) and the shift to low-nitrogen combustion (using low-nitrogen burner and OFA technology), the flame temperature in the main combustion area of the boiler decreases, the thermal-type NOx is reduced, and the volatile content of bituminous coal is higher in the anoxic atmosphere of the main combustion zone where the excess air coefficient is small. The intermediate reductive products tend to produce more, which can restrain and reduce NOx. Therefore, the concentration of NOx emissions can be greatly reduced. NOx average emissions at the economizer outlet decreased by 68%, from 864 mg/Nm<sup>3</sup> to 279.4 mg/Nm<sup>3</sup>. A low-temperature economizer uses waste heat to heat feed water, which reduces coal consumption by about 1.32 g/(kW·h). The coal consumption for power supply after modification is reduced by 9.83 g/(kW·h) and the annual energy saving is 16,776 tons of standard coal, while the total carbon dioxide emissions reduction is 41,213.60 tons after the unit modification. |
| first_indexed | 2024-03-09T16:52:43Z |
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| id | doaj.art-5dd65407c2df449b95fb4ac461edd8d0 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-09T16:52:43Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-5dd65407c2df449b95fb4ac461edd8d02023-11-24T14:38:38ZengMDPI AGEnergies1996-10732022-12-011524953310.3390/en15249533Research on the Modification of Coal Adaptability and Carbon Emissions Reduction Technology for Coal-Fired BoilersDan Peng0Ben Wang1Xingfei Cai2Lei Bei3Henan Engineering Technology Research Center for Energy Conversation and Environmental Protection in Power Plant, Zhengzhou Electric Power College, Zhengzhou 450000, ChinaState Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, ChinaShenzhen Zhongyuan Environmental Technology Co., Ltd., Shenzhen 518054, ChinaState Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, ChinaIn order to solve the problems of the high temperature of flue gas, low boiler efficiency, and the high concentration of nitrogen oxide (NOx) emissions for a 330 MW boiler fired with lean coal in a power plant, an adaptation modification by using different type of coals in the power generation unit (including pulverizing system, burners, heating surface, and so on) was carried out. The performances of boilers were tested under different combustion conditions before and after the modification. The results of the test show that the volatile content is higher and easy to burn out, and the combustible content of fly ash and slag are greatly reduced after the change in coal type (while lean coal is changed into bituminous coal). At the same time, the low-temperature economizer can greatly reduce the flue gas temperature, thus increasing the efficiency from 90.36% (lean coal, corrected) to 92.71% (bituminous coal). After the change in coal type (lean coal to bituminous coal) and the shift to low-nitrogen combustion (using low-nitrogen burner and OFA technology), the flame temperature in the main combustion area of the boiler decreases, the thermal-type NOx is reduced, and the volatile content of bituminous coal is higher in the anoxic atmosphere of the main combustion zone where the excess air coefficient is small. The intermediate reductive products tend to produce more, which can restrain and reduce NOx. Therefore, the concentration of NOx emissions can be greatly reduced. NOx average emissions at the economizer outlet decreased by 68%, from 864 mg/Nm<sup>3</sup> to 279.4 mg/Nm<sup>3</sup>. A low-temperature economizer uses waste heat to heat feed water, which reduces coal consumption by about 1.32 g/(kW·h). The coal consumption for power supply after modification is reduced by 9.83 g/(kW·h) and the annual energy saving is 16,776 tons of standard coal, while the total carbon dioxide emissions reduction is 41,213.60 tons after the unit modification.https://www.mdpi.com/1996-1073/15/24/9533coal adaptabilitycomprehensive modificationcarbon emission reduction technologypulverizing systemboiler performanceNOx |
| spellingShingle | Dan Peng Ben Wang Xingfei Cai Lei Bei Research on the Modification of Coal Adaptability and Carbon Emissions Reduction Technology for Coal-Fired Boilers Energies coal adaptability comprehensive modification carbon emission reduction technology pulverizing system boiler performance NOx |
| title | Research on the Modification of Coal Adaptability and Carbon Emissions Reduction Technology for Coal-Fired Boilers |
| title_full | Research on the Modification of Coal Adaptability and Carbon Emissions Reduction Technology for Coal-Fired Boilers |
| title_fullStr | Research on the Modification of Coal Adaptability and Carbon Emissions Reduction Technology for Coal-Fired Boilers |
| title_full_unstemmed | Research on the Modification of Coal Adaptability and Carbon Emissions Reduction Technology for Coal-Fired Boilers |
| title_short | Research on the Modification of Coal Adaptability and Carbon Emissions Reduction Technology for Coal-Fired Boilers |
| title_sort | research on the modification of coal adaptability and carbon emissions reduction technology for coal fired boilers |
| topic | coal adaptability comprehensive modification carbon emission reduction technology pulverizing system boiler performance NOx |
| url | https://www.mdpi.com/1996-1073/15/24/9533 |
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