大型电厂2×1000MW机组间接空冷系统环境风影响分析

Influence of Wind about Indirect Air-cooling Systems of a 2×1 000 MW Power Plant

间接空冷系统作为一种有效的节水型火力发电冷却技术、是我国西北等缺水地区新建采用的主要电厂冷却系统形式之一。间接空冷系统在环境风特别是高温大风条件下的散热能力及变化规律值得深入研究。利用计算流体力学方法,对一个2×1 000 MW大型电厂间接空冷系统实例进行了计算。通过对空冷塔及周围速度场温度等流场细节的分析,从经济型和安全性两个方面分析了系统散热能力的变化规律。结果表明,小风条件下间接空冷系统散热能力较好,背压波动幅度很小;大风条件下散热能力迅速恶化,高温大风条件下机组难以满发。

Indirect air-cooling system as an effective water-saving cooling technology for thermal power plants,is one of most used cooling system for new constructed power plant in China＇s Northwest regions which are lack of water.The cooling capacity of indirect air-cooling system under conditions of high temperature and strong wind is worthy of further study.Based on CFD method,heat dissipation of a practical power plant with 2×1 000 MW unit is calculated.By analyzing the detailed flow field such as velocity and temperature around cooling towers,variation of cooling capacity is analyzed in the aspects of economy and safety.The result indicates that indirect air-cooling system has good performance under small winds but deteriorates seriously under large winds.