A Novel Ocean Thermal Energy Driven System for Sustainable Power and Fresh Water Supply

Membranes

Yun Zheng¹  Jingru Li¹  Qingfen Ma¹  Xuejin Liu¹  Shenghui Wang¹  Zhongye Wu¹  Hui Lu²  Yijun Shen³  Chengpeng Wang⁴ 

[1] College of Mechanical and Electrical Engineering, Hainan University, Haikou 570228, China;Institute of Environment and Plant Protection, Chinese Academy of Tropical Agriculture Sciences, Haikou 571101, China;State Key Laboratory of Marine Resources Utilization in South China Sea, Haikou 570228, China;The Institute of Seawater Desalination & Multipurpose Utilization, MNR, No.55, Hanghai Road, Nankai District, Tianjin 300192, China;

关键词: OTEC;    organic rankine cycle;    membrane distillation;    thermal efficiency;   

DOI  :  10.3390/membranes12020160

来源: DOAJ

【 摘 要 】

The ocean thermal energy conversion (OTEC) is a potential substitute for traditional power plants in tropical islands and coastal regions. However, the OTEC power generation cycle has low thermal efficiency and the integrated utilization is imperative, in which an OTEC coupled with seawater desalination is the most attractive option. Membrane distillation (MD) has distinct advantages making itself a competitive process for seawater desalination, especially the feature that the drained warm seawater from the OTEC power plant can be recycled, improving the integrated output of the OTEC system. In this study, an innovative OTEC system coupling a power generation sub-cycle (PGC) and a water production sub-cycle (WPC) was proposed, composed of the upstream organic Rankine cycle and the downstream membrane distillation modules. The mass, energy and exergy balance of the individual equipment, the sub-cycles and the whole system were performed by constructing the corresponding balance models. The thermal dynamic parameters were calculated, and the performance of power generation and water production was predicted. The results showed that by coupling with the MD desalination, the thermal efficiency of the OTEC system can be greatly improved from 2.19% to 25.38% while the exergy efficiency changed little. For a 100 kW OTEC power generation cycle, the water production rate approached 58.874 t/d. In addition, the economic analysis based on the electricity and water sale was carried out, and the profit can be improved by extra water production, especially in the Hawaii and Rainbow Beach by nearly 20%.

【 授权许可】

Unknown