Anti-freezing of air-cooled heat exchanger by switching off sectors

作者：Wang, Weijia; Kong, Yanqiang; Huang, Xianwei; Yang, Lijun^*; Du, Xiaoze; Yang, Yongping

来源：Applied Thermal Engineering, 2017, 120: 327-339.

DOI：10.1016/j.applthermaleng.2017.03.106

• Natural draft dry cooling system
• Air-cooled heat exchanger
• Anti-freezing
• Switch off sectors
• Back pressure

With the air side huge heat transfer surface, the air-cooled heat exchanger will take a serious freezing risk in cold winter. Therefore, it is of benefit to the safe operation of natural draft dry cooling system to propose the anti-freezing measures. In this work, the flow and heat transfer models of the cooling air coupling with the circulating water, are developed and numerically simulated for the anti-freezing by switching various sectors off. The local thermo-flow fields of cooling air are presented, and the water side heat loads of various sectors are compared for various cases. The anti-freezing turbine back pressure is proposed and obtained for the energy efficiency analysis. The results show that the sector switching off approach can effectively prevent the air-cooled heat exchanger from freezing and improve the energy efficiency of the cooling system, especially at high wind speeds. Moreover, with the frontal sector switching off, the most energy efficient anti-freezing operation of natural draft dry cooling system can be achieved.

• 出版日期2017-6-25
• 单位华北电力大学; 华北电力大学（保定）