|
|
- 2018
均匀受热垂直上升管内的流动压降特性及界限质量流速
|
Abstract:
界限质量流速G0是垂直管圈水冷壁直流锅炉的重要设计参数之一。当水冷壁管中的质量流速小于G0时，水冷壁呈现正流量响应特性。目前普遍认为G0的范围在1 000~1 200 kg/（m2·s）。在公开文献中，关于G0的影响因素的系统研究还相对较少。该文基于经验关联式和经典的流动压降计算方法，分析了超临界/亚临界压力条件下，均匀受热垂直上升管内水的流动压降随热流密度的变化情况，系统研究了热流密度、管长、管径等因素对G0的影响规律。计算结果表明：热流密度减小，G0增大；管长变短，G0增大；管内径增加，G0增加。
Abstract：The critical mass flux, G0, is a key parameter in the design of vertical water wall in once-through boilers. A vertical water wall has positive flow characteristic only when the mass flux inside the parallel tubes is less than G0. While G0 has been reported to be 1 000-1 200 kg/(m2·s), there are few studies on the factors influencing G0 in the literature. This paper presents a hydrodynamic model based on the classical pressure loss computation method and empirical correlations. The model predicts the pressure drop variation for water flowing upward inside a uniformly heated tube at supercritical/subcritical pressures for various heat fluxes, tube lengths and tube inner diameters. The results show that G0 increases with decreasing heat flux and tube length and decreases with increasing inner diameter.
| [1] | 李燕, 赵新木, 岳光溪, 等. 低质量流速垂直管屏技术的原理与应用分析[J]. 热能动力工程, 2006, 21(6):640-643, 647. LI Y, ZHAO X M, YUE G X, et al. Analysis of working principle and application of low mass flow-speed vertical tube-platen technology[J]. Journal of Engineering for Thermal Energy and Power, 2006, 21(6):640-643, 647. (in Chinese) |
| [2] | 王为术. 超临界锅炉内螺纹水冷壁管流动传热与水动力特性[M]. 北京:中国电力出版社, 2012. WANG W S. Convective heat transfer and hydrodynamic characteristics of supercritical boiler rifle tube[M]. Beijing:China Electric Power Press, 2012. (in Chinese) |
| [3] | GRIEM H, K？HLER W, SCHMIDT H. Heat transfer, pressure drop and stresses in evaporator water walls[J]. VGB Power Tech, 1999, 79(1):26-35. |
| [4] | 吕俊复. 超临界循环流化床锅炉水冷壁热负荷及水动力研究[D]. 北京:清华大学, 2005. Lü J F. Investigation on heat flux and hydrodynamics of water wall of a supercritical pressure circulating fluidized bed boiler[D]. Beijing:Tsinghua University, 2005. (in Chinese) |
| [5] | 周旭, 杨冬, 肖峰, 等. 超临界循环流化床锅炉中等质量流速水冷壁流量分配及壁温计算[J]. 中国电机工程学报, 2009, 29(26):13-18. ZHOU X, YANG D, XIAO F, et al. Mass flow rate profile and metal temperature calculation in water wall of an supercritical circulating fluidized bed boiler at medium mass flow rate[J]. Proceedings of the CSEE, 2009, 29(26):13-18. (in Chinese) |
| [6] | 王为术, 朱晓静, 毕勤成, 等. 超临界W型火焰锅炉垂直水冷壁低质量流速条件下热敏感性研究[J]. 中国电机工程学报, 2010, 30(20):15-21. WANG W S, ZHU X J, BI Q C, et al. Study on thermal sensitivity characteristics of vertical membrane water wall in supercritical pressure W shaped flame boiler[J]. Proceedings of the CSEE, 2010, 30(20):15-21. (in Chinese) |
| [7] | 崔鹏. 超超临界锅炉垂直管屏水冷壁流动特性研究[D]. 保定:华北电力大学, 2010. CUI P. The study for the flow characteristics of vertical tube platen water cooled wall in the ultra-supercritical boiler[D]. Baoding:North China Electric Power University, 2010. (in Chinese) |
| [8] | 黄承懋. 锅炉水动力学及锅内传热[M]. 北京:机械工业出版社, 1982. HUANG C M. Boiler hydrodynamics and heat transfer[M]. Beijing:China Machine Press, 1982. (in Chinese) |
| [9] | CHURCHILL S W. Friction-factor equation spans all fluid-flow regimes[J]. Chemical Engineering, 1977, 84(24):91-92. |
| [10] | WANG L, YANG D, SHEN Z, et al. Thermal-hydraulic calculation and analysis of a 600 MW supercritical circulating fluidized bed boiler with annular furnace[J]. Applied Thermal Engineering, 2016, 95:42-52. |
| [11] | TUCAKOVIC D R, STEVANOVIC V D, ZIVANOVIC T, et al. Thermal-hydraulic analysis of a steam boiler with rifled evaporating tubes[J]. Applied Thermal Engineering, 2007, 27(2-3):509-519. |
| [12] | 张大龙, 吴玉新, 张海, 等. 低质量流率垂直管圈超临界煤粉锅炉的水动力特性分析[J]. 中国电机工程学报, 2014, 34(32):5693-5700. ZHANG D L, WU Y X, ZHANG H, et al. Hydrodynamic characteristics of vertical tubes with low mass flux in supercritical pulverized coal boiler[J]. Proceedings of the CSEE, 2014, 34(32):5693-5700. (in Chinese) |
| [13] | WANG H, CHE D F. Positive flow response characteristic in vertical tube furnace of supercritical once-through boiler[J]. Journal of Thermal Science and Engineering Applications, 2014, 6(3):031002. |
| [14] | SIEMENS A G. BENSON boilers for maximum cost-effectiveness in power plants[R]. Power Generation, 2000. |
| [15] | 周星龙, 程乐鸣, 夏云飞, 等. 600MW循环流化床锅炉水冷壁和中隔墙传热特性[J]. 中国电机工程学报, 2014, 34(2):225-230. ZHOU X L, CHENG L M, XIA Y F, et al. Heat transfer characteristic of water wall and partition wall in a 600 MW CFB boiler[J]. Proceedings of the CSEE, 2014, 34(2):225-230. (in Chinese) |
| [16] | ZHANG M, BIE R S, YU Z Z, et al. Heat flux profile of the furnace wall of a 300 MWe CFB boiler[J]. Powder Technology, 2010, 203(3):548-554. |
| [17] | ZHANG R Q, YANG H R, HU N, et al. Experimental investigation and model validation of the heat flux profile in a 300 MW CFB boiler[J]. Powder Technology, 2013, 246:31-40. |
| [18] | 吕俊复, 于龙, 岳光溪, 等. 循环流化床锅炉水冷壁的热流密度分布[J]. 动力工程, 2007, 27(3):336-340. Lü J F, YU L, YUE G X, et al. Heat flux distribution along water walls of circulating fluidized boilers[J]. Journal of Power Engineering, 2007, 27(3):336-340. (in Chinese) |
| [19] | PAN J, WU G, YANG D. Thermal-hydraulic calculation and analysis on water wall system of 600 MW supercritical CFB boiler[J]. Applied Thermal Engineering, 2015, 82:225-236. |
| [20] | 吕俊复, 吴玉新, 李舟航, 等. 气液两相流动与沸腾传热[M]. 北京:科学出版社, 2017. Lü J F, WU Y X, LI Z H, et al. Gas-liquid two phase flow and boiling heat transfer[M]. Beijing:Science Press, 2017. (in Chinese) |
| [21] | ОСМАЧКИН В С. Трудыи международной конферециипо теплопередаче:Париж, 1970. |
| [22] | CHISHOLM D. The influence of mass velocity on friction pressure gradients during steam-water flow[J]. Proceedings of the Institution of Mechanical Engineers, Conference Proceedings, 1967, 182(8):336-341. |
| [23] | PAN J, YANG D, CHEN G M, et al. Thermal-hydraulic analysis of a 600 MW supercritical CFB boiler with low mass flux[J]. Applied Thermal Engineering, 2012, 32:41-48. |
| [24] | SANKAR G, RAO A C, SESHADRI P S, et al. Techniques for measurement of heat flux in furnace waterwalls of boilers and prediction of heat flux-A review[J]. Applied Thermal Engineering, 2016, 103:1470-1479. |
