华电技术 ›› 2016, Vol. 38 ›› Issue (1): 13-17.

• 研究与开发 • 上一篇    下一篇

冬季低风速下空冷机组蛇形翅片管的换热和阻力特性

  

  1. 1.神华国能蒙东能源有限公司,内蒙古呼伦贝尔〓021000 2.华北电力大学 能源动力与机械工程学院,北京〓102206
  • 出版日期:2016-01-25 发布日期:2016-03-15

The heat transfer and flow resistance characteristics of snake like finned tubes of air cooling unit at low wind speed in winter

  1. 1.Shenhua Guoneng Mengdong Energy Corporation Limited, Hulunbeir 021000,China; 2.School of Energy, Power and Mechanical Engineering, North China Electric Power University,Beijing 102206, China
  • Online:2016-01-25 Published:2016-03-15

摘要:

摘要:在环境温度较低的冬季,为了防止空冷凝汽器翅片管束低负荷工况下发生冻结,风机被迫低速运行或停运,因此有必要分析和研究低风速下翅片管的传热特性和阻力特性及自然通风时空冷系统的状态。利用流体计算软件模拟了环境温度、翅片管束壁面温度和空气入口速度对翅片管温度场和速度场的影响规律。建立了直接空冷系统自然通风的空气流动推动力生成模型,在数值模拟的基础上分析了单排翅片管束的阻力特性和传热特性,通过升力与阻力的平衡得出某工况下自然通风空气的流速,并计算了对应的传热系数,为直接空冷凝汽器在低风速下的运行和优化设计提供依据。

关键词: 关键词:空冷机组, 数值模拟, 蛇形翅片管, 传热特性, 阻力特性

Abstract:

Abstract:In winter, the ambient temperature is relatively low and the fan below the direct air cooling condenser is forced to run at low flow rate or shutdown in order to prevent the finned tube bundlesfrozen under low heat load conditions. Therefore, it is necessary to study the heat transfer and flow resistance characteristics of finned tubesat low wind speed, as well as the air cooling system status under natural ventilation
condition. This paper simulated the influence rules of ambient temperature, wall temperature of finned tubes and inlet velocity of air to the velocity and temperature fields of finned tubes using Fluent, and built a driving force generation model of airflow for direct air
cooling condenser under natural ventilation condition. On the basis of numerical simulation, this paper analyzed the heat transfer and flow resistance characteristics of single row snakelikefinned tubes, obtained the natural ventilation air flow rate under certain condition through the balance of the lift and drag, and calculated the corresponding heat transfer coefficient. It provided a reference for the optimization design of direct aircooling condenserthat operating at low wind speed.

Key words: Keywords:air cooling unit, numerical simulation, snake like finned tubes, heat transfercharacteristic, flow resistance characteristic