# Thermal–Hydraulic Calculation and Analysis on Water Wall System of a 700 MWe Ultra-Supercritical CFB Boiler

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## Abstract

**:**

## 1. Introduction

_{x}is limited by controlling the combustion temperature, air staging, lowering excess air, flue gas treatment, controlling the cyclone performance, controlling the coal particle size, or SNCR, resulting in better environmental performance [6,7,8,9]. In addition, SO

_{2}emissions can be controlled by increasing the cyclone efficiency or appropriately reducing the particle size of the limestone, approaching a more ideal desulfurization efficiency [10].

## 2. Boiler Structure and Design Parameters of Water Wall System

## 3. Mathematical Model and Calculation Method

_{X}, D

_{Y}, and D

_{Z}are the relative suspension densities of solid materials in the three-dimensional direction in the furnace.

_{1}to f

_{4}are the same as the method in the literature [12].

## 4. Calculation Results and Discussion

#### 4.1. Hydrodynamic Characteristics at Different Loads

#### 4.2. Heat Flux Distribution

#### 4.3. Outlet Fluid Temperature

#### 4.4. Metal Temperature Distribution

## 5. Conclusions

## Funding

## Data Availability Statement

## Conflicts of Interest

## References

- Cai, R.; Lu, J.; Ling, W. Progress of supercritical and ultra-supercritical circulating fluidized bed boiler technology. Electr. Power
**2016**, 49, 1–7. [Google Scholar] - Yu, L.; Lu, J.-F.; Yue, G.-X. Prospective research progress of combustion technology for circulating fluidized beds. J. Eng. Therm. Energy Power
**2004**, 19, 336–342. [Google Scholar] - Koornneef, J.; Junginger, M.; Faaij, A. Development of fluidized bed combustion—An overview of trends, performance and cost. Prog. Energy Combust. Sci.
**2007**, 33, 19–55. [Google Scholar] [CrossRef] - Yue, G.; Cai, R.; Lu, J.; Zhang, H. From a CFB reactor to a CFB boiler–The review of R&D progress of CFB coal combustion technology in China. Powder Technol.
**2017**, 316, 18–28. [Google Scholar] - Lyu, J.; Yang, H.; Ling, W.; Nie, L.; Yue, G.; Li, R.; Chen, Y.; Wang, S. Development of a supercritical and an ultra-supercritical circulating fluidized bed boiler. Front. Energy
**2019**, 13, 114–119. [Google Scholar] [CrossRef] - Ji, J.; Cheng, L.; Wei, Y.; Wang, J.; Gao, X.; Fang, M.; Wang, Q. Predictions of NOx/N2O emissions from an ultra-supercritical CFB boiler using a 2-D comprehensive CFD combustion model. Particuology
**2020**, 49, 77–87. [Google Scholar] [CrossRef] - Blaszczuk, A.; Nowak, W.; Jagodzik, S. Effects of operating conditions on deNOx system efficiency in supercritical circulating fluidized bed boiler. J. Power Technol.
**2013**, 93, 1. [Google Scholar] - Ke, X.; Yao, Y.; Huang, Z.; Zhang, M.; Lyu, J.; Yang, H.; Zhou, T. Prediction and minimization of NOx emission in a circulating fluidized bed combustor: Improvement of bed quality by optimizing cyclone performance and coal particle size. Fuel
**2022**, 328, 125287. [Google Scholar] [CrossRef] - Yan, J.; Lu, X.F.; Zhang, C.F.; Li, Q.J.; Wang, J.P.; Liu, S.R.; Zheng, X.; Fan, X.C. An Experimental Study on the Characteristics of NOx Distributions at the SNCR Inlets of a Large-Scale CFB Boiler. Energies
**2021**, 14, 1267. [Google Scholar] [CrossRef] - Ke, X.; Li, D.; Li, Y.; Jiang, L.; Cai, R.; Lyu, J.; Yang, H.; Zhang, M.; Jeon, C.-H. 1-Dimensional modelling of In-Situ desulphurization performance of a 550 MWe ultra-supercritical CFB boiler. Fuel
**2021**, 290, 120088. [Google Scholar] [CrossRef] - Leckner, B. Hundred years of fluidization for the conversion of solid fuels. Powder Technol.
**2022**, 411, 117935. [Google Scholar] [CrossRef] - Tang, G.; Zhang, M.; Gu, J.; Wu, Y.; Yang, H.; Zhang, Y.; Wei, G.; Lyu, J. Thermal-hydraulic calculation and analysis on evaporator system of a 660 MWe ultra-supercritical CFB boiler. Appl. Therm. Eng.
**2019**, 151, 385–393. [Google Scholar] [CrossRef] - Xin, S.; Wang, H.; Li, J.; Wang, G.; Wang, Q.; Cao, P.; Zhang, P.; Lu, X. Discussion on the Feasibility of Deep Peak Regulation for Ultra-Supercritical Circulating Fluidized Bed Boiler. Energies
**2022**, 15, 7720. [Google Scholar] [CrossRef] - Domenichini, R.; Mancuso, L.; Ferrari, N.; Davison, J. Operating flexibility of power plants with carbon capture and storage (CCS). Energy Procedia
**2013**, 37, 2727–2737. [Google Scholar] [CrossRef] - Henderson, C. Increasing the flexibility of coal-fired power plants. IEA Clean Coal Cent.
**2014**, 15, 15. [Google Scholar] - Cai, R.; Ke, X.; Lyu, J.; Yang, H.; Zhang, M.; Yue, G.; Ling, W. Progress of circulating fluidized bed combustion technology in China: A review. Clean Energy
**2017**, 1, 14. [Google Scholar] [CrossRef] - Zhu, X.; Wang, W.; Xu, W. A study of the hydrodynamic characteristics of a vertical water wall in a 2953t/h ultra-supercritical pressure boiler. Int. J. Heat Mass Transf.
**2015**, 86, 404–414. [Google Scholar] [CrossRef] - Pan, J.; Yang, D.; Yu, H.; Bi, Q.-C.; Hua, H.-Y.; Gao, F.; Yang, Z.-M. Mathematical modeling and thermal-hydraulic analysis of vertical water wall in an ultra supercritical boiler. Appl. Therm. Eng.
**2009**, 29, 2500–2507. [Google Scholar] [CrossRef] - Pan, J.; Wu, G.; Yang, D. Thermal-hydraulic calculation and analysis on water wall system of 600 MW supercritical CFB boiler. Appl. Therm. Eng.
**2015**, 82, 225–236. [Google Scholar] [CrossRef] - Lu, J. Heat Flux Distribution Along Water Walls of Circulating Fluidized Bed Boilers. J. Power Eng.
**2008**, 27, 336–340. [Google Scholar] - Lu, J.; Zhang, J.; Yue, G.; Liu, Q.; Yu, L.; Lin, X.; Li, W.; Tang, Y.; Luo, T.; Ge, R. Method of calculation of heat transfer coefficient of the heater in a circulating fluidized bed furnace. Heat Transf.—Asian Res. Co-Spons. Soc. Chem. Eng. Jpn. Heat Transf. Div. ASME
**2002**, 31, 540–550. [Google Scholar] [CrossRef] - Lyu, J. Investigation on Heat Flux and Hydrodynamics of Water Wall of a Supercritical Pressure Circulating Fluidized Bed Boiler. Ph.D. Thesis, Tsinghua University, Beijing, China, 2004. [Google Scholar]
- JB/Z201-83; The National Standard of the Boiler Hydrodynamics Calculation. Shanghai Power Equipment Packaged Design Research Institute: Shanghai, China, 1983.
- Chen, Y.; Lu, X.; Zhang, W.; Wang, Q.; Chen, S.; Fan, X.; Li, J. An experimental study on the hydrodynamic performance of the water-wall system of a 600 MW supercritical CFB boiler. Appl. Therm. Eng.
**2018**, 141, 280–287. [Google Scholar] [CrossRef]

**Figure 3.**Planform of the water wall and the water-cooled panels. (

**a**) Flow loop division sketch of four-sided water wall; (

**b**) serial number of water wall tubes; (

**c**) Flow loop division sketch of water-cooled panels.

**Figure 5.**Mass flux distribution in the water wall system at different loads: (

**a**) Water wall; (

**b**) Water-cooled panels.

**Figure 6.**Horizontal heat flux distribution on the water wall at different heights: (

**a**) At the height of 22 m; (

**b**) At the height of 52 m.

**Figure 8.**Fluid temperature distribution in the water wall system at different boiler loads: (

**a**) At the outlet of the vertical water wall; (

**b**) At the outlet of the water-cooled panels.

**Figure 9.**Temperature distribution along the flow direction in the water wall system: (

**a**) loop 16; (

**b**) loop 87.

Parameter | Unit | BMCR | 75%BMCR | 50%BMCR | 25%BMCR |
---|---|---|---|---|---|

Total mass flow rate, ${M}_{total}$ | kg/s | 596.67 | 399.44 | 291.94 | 158.06 |

Inlet pressure, ${P}_{in}$ | MPa | 32.2 | 25.6 | 16.9 | 11.4 |

Inlet fluid temperature, ${t}_{in}$ | °C | 352 | 317 | 315 | 288 |

Inlet fluid enthalpy, ${h}_{in}$ | kJ/kg | 1615.97 | 1421.38 | 1420.62 | 1276.07 |

Outlet fluid pressure, ${P}_{out}$ | MPa | 31.50 | 25.12 | 16.48 | 11.07 |

Outlet fluid temperature, ${t}_{out}$ | °C | 422.3 | 403.8 | 396.6 | 342.3 |

Outlet fluid enthalpy, ${h}_{out}$ | kJ/kg | 2513.97 | 2629.51 | 2919.72 | 2848.79 |

Pressure drop | MPa | 0.70 | 0.48 | 0.42 | 0.33 |

Parameter | Unit | BMCR | 75%BMCR | 50%BMCR | 25%BMCR |
---|---|---|---|---|---|

Outlet fluid temperature in water wall | °C | 400.3 | 383.6 | 350.7 | 319.3 |

Outlet fluid enthalpy in the water wall | kJ/kg | 2082.26 | 2048.65 | 2199.00 | 2092.66 |

Outlet fluid temperature in the water-cooled panel | °C | 422.3 | 403.8 | 396.6 | 342.3 |

Outlet fluid enthalpy in water-cooled panel | kJ/kg | 2513.97 | 2629.51 | 2919.72 | 2848.79 |

Pressure drop of vertical water wall | MPa | 0.32 | 0.30 | 0.24 | 0.22 |

Pressure drop of water-cooled panel | MPa | 0.35 | 0.16 | 0.16 | 0.10 |

Pressure drop of vertical water wall system | MPa | 0.70 | 0.48 | 0.42 | 0.37 |

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**MDPI and ACS Style**

Wu, H.; Zhou, T.; Hu, X.; Luo, Y.; Zhang, M.; Yang, H. Thermal–Hydraulic Calculation and Analysis on Water Wall System of a 700 MWe Ultra-Supercritical CFB Boiler. *Energies* **2023**, *16*, 4344.
https://doi.org/10.3390/en16114344

**AMA Style**

Wu H, Zhou T, Hu X, Luo Y, Zhang M, Yang H. Thermal–Hydraulic Calculation and Analysis on Water Wall System of a 700 MWe Ultra-Supercritical CFB Boiler. *Energies*. 2023; 16(11):4344.
https://doi.org/10.3390/en16114344

**Chicago/Turabian Style**

Wu, Haowen, Tuo Zhou, Xiannan Hu, Yongjun Luo, Man Zhang, and Hairui Yang. 2023. "Thermal–Hydraulic Calculation and Analysis on Water Wall System of a 700 MWe Ultra-Supercritical CFB Boiler" *Energies* 16, no. 11: 4344.
https://doi.org/10.3390/en16114344