摘要
热泵储电是一种利用热泵和热机交替循环实现储能和发电的技术,需要热媒和冷媒来储存热量和冷量。储能过程中低温热媒吸热变为高温热媒,发电过程中高温热媒放热恢复为低温热媒。热媒温度决定了压缩机和透平的温比,对系统的往返效率具有很大影响。该文计算分析基于闭式布雷顿循环的热泵储电系统,结论为高温热媒温度升高可以使往返效率增大,低温热媒温度下降则导致往返效率先增大后减小。在给定的设备效率和损失下,当高温热媒温度为550℃时,低温热媒的最优温度为310℃,此时系统达到最高往返效率为61.36%。效率拐点主要归因于系统的储能功率随低温热媒温度几乎呈线性变化,而发电功率则近似为低温热媒温度的二次函数。
Pumped thermal electricity storage(PTES)technology can alternately utilize heat pump and heat engine cycles to achieve energy storage and power generation.It requires heat and cold mediums to store thermal and cryogenic energy.In the process of energy storage,the low-temperature heat medium absorbs heat and then becomes high-temperature heat medium.In the process of power generation,the high-temperature heat medium reverts to low-temperature heat medium by releasing heat.The heat medium temperature determines the temperature ratios of compressors and turbines,and thus has a great influence on the round-trip efficiency of the PTES system.In this paper,a PTES system based on closed Brayton cycle is calculated and analyzed.It is concluded that the system round-trip efficiency can be improved by increasing the temperature of high-temperature heat medium,while it increases first and then decreases with reducing the temperature of the low-temperature heat medium.Given the equipment efficiencies and losses,when the temperature of the high-temperature heat medium is 550℃,the optimal temperature of the low-temperature heat medium is 310℃,leading to the highest system round-trip efficiency of 61.36%.The efficiency inflection point is mainly due to that the energy storage power varies almost linearly with the temperature of the low-temperature heat medium,while the generated electricity power is approximately a quadratic function of the temperature of the low-temperature heat medium.
作者
王际辉
白宁
沈峰
Wang Jihui;Bai Ning;Shen Feng(State Power Investment Corporation Research Institute,Beijing 102209,China)
出处
《太阳能学报》
EI
CAS
CSCD
北大核心
2023年第7期48-54,共7页
Acta Energiae Solaris Sinica
关键词
电能储存
热泵
储热
效率
布雷顿循环
electric energy storage
heat pump
thermal storage
efficiency
Brayton cycle
