全流-双循环地热发电系统分析

Analysis of Geothermal Power Generation by Total Flow System with Binary Cycle

采用全流-双循环地热发电系统对中低温地热水进行利用发电,并与闪蒸蒸汽系统进行比较.理论推导闪蒸蒸汽系统的最佳闪蒸温度,分析比较了全流-双循环系统中各部分的损失,进而提出了降低换热器端差,以减少损的措施.在既定的地热水参数条件下,根据系统模型对全流-双循环系统和闪蒸蒸汽系统进行热力计算.结果显示:全流-双循环系统的最大发电功率比闪蒸系统的最大发电功率高出12.7%;全流-双循环系统的功率随着低温工质蒸发温度的升高而增大;闪蒸蒸汽系统的功率随着闪蒸压力的增大呈先上升后下降的趋势.

A total flow system with binary cycle was used in geothermal power generation with low-medium temperature, and compared with flash system. The optimal flash temperature was derived theoretically. Different parts of the total flow system with binary cycle were analyzed with the exergy loss, so as to propose the direction of reducing the exergy loss and optimizing the system which is reducing the minimum temperature difference of hot side and cold side of heat exchanger. Under the given condition, these two plants were calculated according to their system models. As shown by the calculation result, the maximum total capacity of total flow system with binary cycle is higher than that of the flash system by 12.7%. The power of the total flow system with binary cycle increases with the rise of the evaporation temperature of the organic fluid, and the power of the flash system firstly increases and then decreases while the flash pressure rises up.