Abstract:

Supercritical water oxidation (SCWO) process is suitable for the treatment of high concentration waste liquids. Aiming at the problems of high energy consumption and single energy reuse mode of SCWO treatment system, the energy recovery mode of traditional process flow is introduced, the energy utilization efficiency of the system is analyzed, and the turbine and organic Rankine cycle (ORC) are innovatively used to recover pressure energy and thermal energy, respectively. Aspen Plus was used to establish the energy recovery model of SCWO system to study the influence of different process flows on the system energy efficiency, efficiency and output power. On this basis, the effects of turbine inlet temperature and outlet pressure and orc evaporation temperature on system performance are discussed. The results show that the best energy recovery method is to recover the pressure energy and heat energy of the reaction products in turn. Increasing inlet temperature and outlet pressure of supercritical turbines can improve system performance and the stability of the turbine output power at the same time. Reducing the evaporation temperature of ORC will increase the steam output of the system, but also reduce the generation of directly available electric energy.

Key words: supercritical water oxidation, energy recovery, energy efficiency, exergy efficiency, design

摘要：

超临界水氧化（SCWO）工艺非常适用于高浓度废液的处理。针对目前SCWO处理系统能耗大、能量回用方式单一的问题，介绍了传统工艺流程的能量回收方式，分析了系统能量利用效率，创新性地采用透平和有机朗肯循环（ORC）串联的方式分别对压力能和热能进行回收。利用Aspen Plus建立SCWO系统能量回收模型，研究不同工艺流程对系统能效、㶲效及输出功率的影响，在此基础上探讨透平的入口温度和出口压力、ORC的蒸发温度对系统性能的影响。结果表明：对反应产物依次进行压力能和热能回收为系统最佳能量回收方式；提高透平的入口温度和出口压力均可提高系统的性能，并同时提高透平输出功率的稳定性；降低ORC的蒸发温度会提高系统蒸汽产量，但同时也减少了可直接利用电能的产生量。

关键词: 超临界水氧化, 能量回收, 能量效率, ?效率, 设计