超临界CO_(2)余热利用系统动态特性及最优负荷控制策略研究

Research on Dynamic Characteristics of Supercritical CO_(2)Waste Heat Utilization System and Optimal Load Control Strategy

为了解决超临界二氧化碳(SCO_(2))余热利用系统内参数动态耦合特性不明确,以及系统内多循环造成负荷控制复杂的问题,建立SCO_(2)余热利用系统动态特性模型,获得燃气轮机排气温度和质量流量扰动下系统热力学参数响应特征,对比不同负荷跟随控制策略,确定SCO_(2)余热利用系统变负荷过程中最优负荷控制策略。结果表明:在燃气轮机排气温度和质量流量扰动时,SCO_(2)余热利用系统对燃气轮机排气温度变化更为敏感,在燃气轮机排气温度扰动下系统总效率是燃气轮机排气流量扰动下的2.64倍。在SCO_(2)余热利用系统由100%负荷降至95%负荷的过程中,超临界负荷跟随策略为最优负荷控制策略,其与跨临界负荷跟随及按比例分配策略相比,具有更好的负荷跟随能力和更高的系统总效率。

In order to solve the problems of unclear dynamic coupling characteristics of parameters within the SCO_(2)waste heat utilization system and the complexity of load control due to multiple cycles within the system,this paper established a dynamic characteristic model of SCO_(2)waste heat utilization system,ob-tained the response characteristics of system thermodynamic parameters under the disturbance of gas tur-bine exhaust temperature and mass flow rate,and compared the different load following control strategies to determine the optimal load control strategy of SCO_(2)waste heat utilization system during the variable load process.The results show that the SCO_(2)waste heat utilization system is more sensitive to the gas tur-bine exhaust temperature change under gas turbine exhaust temperature and mass flow rate disturbance,and the total efficiency of the SCO_(2)waste heat utilization system under gas turbine exhaust temperature disturbance is 2.64 times higher than that under gas turbine exhaust flow rate disturbance.The supercritical load following strategy is the optimal load control strategy during the reduction of the total load of the SCO_(2)waste heat utilization system from 100%to 95%,which has a better load following capability and the highest total efficiency of the supercritical CO_(2)waste heat utilization system compared with the transcritical load following and the proportional allocation strategies.