应用于EGS的两级闪蒸-Kalina循环联合发电系统热力性能研究

Research on thermodynamic performance of double flash-Kalina cycle combined power generation system for EGS

为更高效利用增强型地热系统(EGS)热源,在闪蒸系统和Kalina循环系统基础上,提出了两级闪蒸-Kalina循环联合发电系统。通过建立联合系统的热力学模型,综合考虑热源温度、冷却水温度和氨质量浓度等参数,研究闪蒸温度在90~150℃对系统热力性能的影响。研究结果表明:联合系统的热力性能随着闪蒸温度的提高呈先增大后减小的趋势,在不同因素下都存在一个最佳闪蒸温度。热源温度提高,对应的最佳闪蒸温度线性增大,而冷却水温度和氨质量浓度提高,对应的最佳闪蒸温度则基本相同;在同一闪蒸温度下,热源温度越高、冷却水温度越低,系统性能越好;而当氨质量浓度提高到0.8后,对系统性能的影响并不显著。

In order to utilize the heat source of enhanced geothermal system(EGS)more efficiently,a double flashKalina cycle combined power generation system is proposed based on the flash system and the Kalina cycle system.By establishing the thermodynamic model of the combined power system and considering the parameters of heat source temperature,cooling water temperature and ammonia mass concentration,the influence of flash temperature in the range of 90~150°C on the thermal performance of the system is studied.The results show that the thermal performance of the combined system increases firstly and then decreases with the increase of flashing temperature.There is an optimal flashing temperature under different conditions.With the rise of heat source temperature,the corresponding optimum flash temperature will increase linearly,and the cooling water temperature and ammonia mass concentration increase,while the corresponding optimum flash temperatures keep steady.At the same flash temperature,with the higher heat source temperature and the lower cooling water temperature,the system performance is better.Ammonia concentration has no significant impact on system performance when growing up to 0.8.