• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>International Journal of Heat and Mass Transfer >The transient start-up process of natural draft dry cooling towers in dispatchable thermal power plants
【24h】

The transient start-up process of natural draft dry cooling towers in dispatchable thermal power plants

机译：可调度热电厂自然通风干式冷却塔的暂态启动过程

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A one-dimensional (1-D) transient cooling tower model is presented that can be used to simulate the start-up process of natural draft dry cooling towers (NDDCTs). The model simulates the behaviour of a NDDCT following a step increase in the heat exchanger temperature. The start-up process is analysed in two successive stages. In the first stage, the dominant mechanism is natural convection operating through generation and propagation of hot plumes rising from the heat exchanger surface. An understanding of different phases of plume development based on scaled analysis helps to predict the air flow development in this first stage. In the second stage, the air flow is driven by the draft caused by the difference in the inside and outside densities. The cooling tower system air flow development in the second stage is simulated through a quasi-steady state solution of the well-known draft equation, The simulation is repeated for three different input temperatures. The results show that the higher the input temperature, the higher is the inlet air velocity and shorter the start-up process. The results are validated against data from the commissioning tests of the University of Queensland natural draft cooling tower Gatton test rig. This study aims to help fill the knowledge gap in understanding the NDDCT start-up process. This understanding is important to the employment of NDDCTs in future thermal power plants operating in dispatchable mode. (C) 2018 Elsevier Ltd. All rights reserved.
机译：提出了一维（1-D）瞬态冷却塔模型，该模型可用于模拟自然通风干式冷却塔（NDDCT）的启动过程。该模型模拟了随着热交换器温度的逐步升高，NDDCT的行为。启动过程分为两个连续的阶段进行分析。在第一阶段，主要的机制是自然对流，该自然对流通过从热交换器表面升起的热羽流的产生和传播进行操作。基于比例分析对羽状流发展不同阶段的理解有助于预测第一阶段的气流发展。在第二阶段，气流由内部和外部密度差异引起的气流驱动。通过众所周知的吃水方程的准稳态解来模拟第二阶段冷却塔系统的气流发展，并针对三个不同的输入温度重复进行该模拟。结果表明，输入温度越高，进气速度越高，启动过程越短。根据昆士兰大学自然通风冷却塔加顿试验台的调试测试数据验证了结果。这项研究旨在帮助填补了解NDDCT启动过程的知识空白。这种理解对于在未来以可调度模式运行的热电厂中使用NDDCT非常重要。 （C）2018 Elsevier Ltd.保留所有权利。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号