1 000 MW超超临界机组带可调节级的十级回热系统设计和经济性分析

针对神华国华永州发电厂一期（2×1 000 MW）工程一次再热机组采用带可调节级10级回热系统的可行性和经济性进行了深入的论证和分析：采用串联方式将新增的0号高压加热器（以下简称高加）布置在前置蒸汽冷却器的上游,设置调节阀调节抽汽压力为0号高加供汽,在部分负荷工况下,相比常规型不可调节级的10级回热系统,0号高加的蒸汽压力得到了提高,给水温度可进一步提升;热耗下降12~38 kJ/（kW·h）,煤耗降低效果显著,2台机组20年综合折现收益约5 308万元,具有更高的热经济性。

Design and Economic Analysis of Adjustable Ten-Stage Heat Regeneration System for 1 000-MW Ultra-Supercritical Unit

In this paper, the in-depth study is conducted on the feasibility and economics of the adjustable ten-stage heat regeneration system for the two 1 000-MW ultra-supercritical units with one reheat cycle in Shenhua Guohua Yongzhou Power Plant (2×1 000 MW) Phase I Project. The serial No.0 high-pressure heater, equipped with the control valve to regulate the extraction pressure, is placed upstream the outer steam cooler. Under the partial load conditions, compared with the ten-stage heat regeneration system with nonadjustable stage, the initial steam pressure of the No.0 HP heater and the feedwater temperature are both improved, which lowers the turbine heat rate by 12~38 kJ/kWh, showing significant decrease of coal consumption. As a result, the total comprehensive benefit of the two units in 20 years can be as much as 53.08 million yuan.