熔盐塔式太阳能热发电站中蒸汽发生系统水循环方式的对比分析

COMPARATIVE ANALYSIS OF WATER CIRCULATION MODES IN STEAM GENERATION SYSTEM OF MOLTEN SALT TOWER CSP STATION

蒸汽发生系统水循环方式的选择对熔盐塔式太阳能热发电站的投资经济性及安全稳定运行至关重要。对熔盐塔式太阳能热发电站的蒸汽发生系统进行了介绍,对蒸汽发生系统的两种水循环方式——自然循环方式和强制循环方式进行了技术性和经济性对比分析。分析结果表明:在目前熔盐塔式太阳能热发电站采用高温、超高压参数下,自然循环方式及强制循环方式技术路线均能满足熔盐塔式太阳能热发电站蒸发换热的需求;若选择强制循环方式,在设备选型时,应将强制循环泵的结构及运行环境作为重点进行综合分析;结合国内已建成的熔盐塔式太阳能热发电项目的运行经验及太阳能热发电技术的发展趋势,熔盐塔式太阳能热发电站蒸汽发生系统的出口主蒸汽压力在亚临界以下(<16 MPa)时,从技术性、经济性及运行维护方面综合考虑,水循环方式推荐采用自然循环方式。以期为熔盐塔式太阳能热发电站蒸汽发生系统的设计选型提供参考。

The selection of water circulation modes for steam generation system is crucial for the investment economy and safe and stable operation of molten salt tower CSP stations.This paper introduces the steam generation system of molten salt tower CSP station,and comparative analysis is conducted on the technical and economic aspects of using natural circulation mode or forced circulation mode for steam generation systems.The analysis results show that under the current high temperature and ultra-high pressure parameters used in the molten salt tower CSP station,both natural circulation mode and forced circulation mode technology routes can meet the evaporation and heat transfer needs of the molten salt tower CSP station.If the forced circulation mode is chosen,the structure and operating environment of the forced circulation pump should be taken as the focus for comprehensive analysis when selecting equipment.Based on the operating experience of completed molten salt tower CSP projects in China and the development trend of CSP technology,when the outlet main steam pressure of the steam generation system of molten salt tower CSP station is below the subcritical(16 MPa),considering the technical,economic,operational and maintenance aspects,it is recommended water circulation method to use natural circulation mode.To provide reference for the design and selection of steam generation systems of molten salt tower CSP stations.