潮汐能聚能增压方案的热力学性能分析

Thermodynamic Analysis on Plan of Seawater Pressurization Driven by Tidal Energy

该文提出了一种利用潮汐能直接驱动反渗透海水淡化装置的方法,该方法的核心是潮汐能聚能增压方案。建立了该方案的无限库容模型,分别采用熵分析法和分析法对该方案的可行性进行了研究,并给出了聚能增压过程的增压比和流量比之间的量变关系,得出了聚能增压过程的能量转换效率和效率随高压海水压力变化的规律。结果表明,利用潮汐的能量可直接将低水头海水变为高压海水,从而可以替代电能为反渗透海水淡化提供高压海水;理论上要得到一定高压力的高压海水,就要以减小高压海水的流量作为代价;水位差越大,聚能增压的效果越好;聚能增压过程的能量转换效率和效率相等,提高效率可通过提升水位差或减小高压海水的压力来实现。

A new method to achieve reverse osmosis（RO） desalination using tidal energy was presented. The plan of seawater pressurization driven by tidal energy was regarded as its core. The infinite storage volume model was adopted, and the feasibility of this plan was studied based on entropy analysis and exergy analysis, respectively. The relationship between pressure ratio and flow ratio in seawater pressurization process was obtained, and the relations of energy conversion efficiency（and exergetic efficiency） on the pressure of production water were also studied. The results show that by utilizing directly tidal energy the low pressure seawater can be changed into high pressure seawater which can be supplied for RO plant. Theoretically, a big enough pressure can be achieved by reducing the flux rate of high pressure seawater. The higher the water-head is, the better the pressurization effect is. The exergetic efficiency is equal to the energy conversion efficiency, and both of them increase as water-head increases or the production water pressure reduces.