联合循环中蒸汽底循环系统设计优化研究

遵循“温度对口,梯级利用”的原则,基于温区概念,建立了联合循环底循环系统设计优化模型,并通过实例对一具体的联合循环底循环系统进行了优化研究,得出了一些有价值的结论。研究结果表明:单压余热锅炉底循环系统存在一个最优的汽包压力,使联合循环系统性能最优;对于双压余热锅炉底循环系统,高压汽包压力并不是越高越好,存在一个合理的选择区域,一定高压汽包压力下存在一个最佳的低压汽包压力使系统性能最优;与单压余热锅炉底循环系统相比,双压余热锅炉底循环系统余热利用率更高,从而更好地实现了能的梯级利用。

Design optimization of steam bottom cycle in combined cycle system

According to the principle of energy cascade utilization and applying the temperature phase concept,the authors build the design optimization model of bottom cycle system and develops corresponding programs.Some valuable conclusionshave beendrawn througha casestudy. The results show that for single-pressurebottom-cycle system, there exists an optimal high pressure steam drum pressure that makes combined cycle system havethe best performance. For double-pressure bottom-cycle system, there exists a suitable parameter area for highpressure steam drum pressure. For a definite high pressure steam drum pressure, there exists an optimal lowpressure steam drum pressure. In contrast to single-pressure bottom cycle system, double-pressure bottom cyclesystem has a higher efficiency of heat recovery and can realize energy cascade utilization better.