低温显热驱动的多效蒸发海水淡化系统改进

Improvement of multi-effect distillation desalination system driven by low temperature sensible heat

中文关键词: 海水淡化  多效蒸发  低温显热  系统改进

英文关键词: desalination  multi-effect distillation  low temperature sensible heat  system improvement

中文摘要:

      “双碳”目标背景下，低品位余热的高效回收和海水淡化的节能降耗势在必行。针对低温显热驱动的多效蒸发（MED）海水淡化系统，本文提出了一种改进流程-闪蒸增强级联MED（FBCMED）系统。通过模拟计算，将FBCMED与基础MED、文献中分布增强MED（DBMED）系统进行热力学和经济性能对比研究。结果表明，在65°C至95°C的热源温度范围内，FBCMED系统在余热性能比（PRwh）方面表现最优，相比于MED系统，FBCMED系统增幅为31%-51%，而DBMED系统增幅仅为28%-38%。不过，FBCMED系统的比泵功耗在三种系统中也是最高的。尽管总投资成本较MED系统有所增加，但FBCMED系统d 单位产水投资成本（SCC）在不同热源温度下均展现出更好的改进效果，SCC降幅达到4.15%-6.5%。本研究可为低温显热驱动的MED海水淡化系统的优化设计提供有益参考。

英文摘要:

      In the context of the "dual carbon" goals, addressing the imperative need for efficient recovery of low-grade waste heat and energy conservation in seawater desalination is crucial. This study focused on the multi-effect distillation (MED) desalination system driven by low-temperature sensible heat and proposed a novel improved process: the flash boosted cascade MED (FBCMED) system. Based on simulation calcu-lations, a comparison of the thermodynamic and economic performances was conducted among three sys-tems: the baseline MED, the distributed boosted MED (DBMED) from literature, and the proposed FBC-MED. Results show that the FBCMED system outperforms others in waste heat performance ratio (PRwh) at heat source temperatures ranging from 65°C to 95°C. Compared to the baseline MED, PRwh of the FBC-MED system increases by 31%-51%, while the DBMED system increases by only 28%-38%. However, the FBCMED system also has the highest normalized pumping power consumption. Despite higher total investment cost than the MED system, the FBCMED system demonstrates better cost-effectiveness in terms of specific capital cost (SCC) for water production across various heat source temperatures, with a reduction of 4.15%-6.5%. This study could provide valuable insights for optimizing MED seawater desal-ination systems driven by low-temperature sensible heat.