Zheng Yanjie, Zhao Yunsheng, Liang Shen, Zheng Hongfei
School of Mechanical and Vehicular Engineering, Beijing Institute of Technology, Beijing 100081, China.
Entropy (Basel). 2018 Oct 26;20(11):822. doi: 10.3390/e20110822.
Based on the reversible heat engine model, theoretical analysis is carried out for economic performance of a solar tower power plant (STPP) combined with multi-effect desalination (MED). Taking total revenue of the output power and the fresh water yield per unit investment cost as the economic objective function, the most economical working condition of the system is given by analyzing the influence of the system investment composition, the receiver operating temperature, the concentration ratio, the efficiency of the endoreversible heat engine, and the relative water price on the economic parameters of the system. The variation curves of the economic objective function are given out when the main parameter is changed. The results show that the ratio of water price to electricity price, or relative price index, has a significant impact on system economy. When the water price is relatively low, with the effect numbers of the desalination system increasing, and the economic efficiency of the overall system worsens. Only when the price of fresh water rises to a certain value does it make sense to increase the effect. Additionally, the threshold of the fresh water price to the electricity price ratio is 0.22. Under the conditions of the current price index and the heliostat (or reflector), the cost ratio and the system economy can be maximized by selecting the optimum receiver temperature, the endoreversible heat engine efficiency, and the optimum concentration ratio. Given the receiver surface temperature and the endoreversible heat engine efficiency, increasing the system concentration ratio of the heliostat will be in favor of the system economy.
基于可逆热机模型，对结合多效蒸发淡化（MED）的太阳能塔式发电厂（STPP）的经济性能进行了理论分析。以输出功率的总收益和单位投资成本的淡水产量作为经济目标函数，通过分析系统投资构成、接收器运行温度、聚光比、内可逆热机效率以及相对水价对系统经济参数的影响，给出了系统的最经济运行工况。给出了主要参数变化时经济目标函数的变化曲线。结果表明，水价与电价之比，即相对价格指数，对系统经济性有显著影响。当水价相对较低时，随着淡化系统效数的增加，整个系统的经济效率变差。只有当淡水价格上升到一定值时，增加效数才是有意义的。此外，淡水价格与电价之比的阈值为0.22。在当前价格指数和定日镜（或反射镜）的条件下，通过选择最佳的接收器温度、内可逆热机效率和最佳聚光比，可以使成本比和系统经济性最大化。给定接收器表面温度和内可逆热机效率，提高定日镜的系统聚光比将有利于系统经济性。
