基于跨临界循环的卡诺电池储能系统构型优化

Configuration Optimization of Carnot Battery Energy Storage System Based on Transcritical Cycles

卡诺电池是一种新兴有前景可实现大规模储能的技术。本文基于跨临界CO2循环的卡诺电池储能系统,首先根据储热介质和有无回热情况,设计了 6种系统构型,并对其热力参数进行优化;之后,从热-经济学的角度开展了对比分析,获得了最优系统构型。结果表明:带回热后的卡诺电池系统比无回热系统综合效率有所提高;其中使用菜籽油时获得最高综合效率(75.28%)和储能密度(36.61 kWh·m^(-3)),且比无回热的系统分别增大了 36.67%和25.68 kWh·m^(-3)。6种卡诺电池系统构型的总投资成本在(11.5~36.3)×10^(6) USD,单位能量的投资成本在954~3028 USD.kW^(-1)·h^(-1);换热器成本占比最高可达54%,储热罐的成本占比最高可达14%,膨胀机和压缩机成本占比分别在18%~31%和14%~26%之间;对比来看,使用导热油并加入回热的卡诺电池系统经济性最好。

Carnot battery is a novel and promising technology that can realize large-scale energy storage.This investigation focuses on a Carnot battery energy storage system based on the CO_(2) transcritical cycle,six system configurations employing different thermal energy storage materials and with or without recuperation are firstly designed and the thermodynamic parameters are optimized.Then,detailed comparison analyses from thermo-economic perspectives are conducted and the optimal system configuration is obtained.The main results reveal that the roundtrip efficiency of the recuperated Carnot battery system enhances when compared to the non-recuperated system;the recuperated system using rapeseed oil as the storage material achieves the highest roundtrip efficiency(75.28%) and energy density(36.61 kWh·m^(-3)),which is respective 36.67% and 25.68 kWh·m^(-3) higher than the non-recuperated system.Among six different system configurations of the Carnot battery,the total capital costs range from 11.5 to 36.3 106 USD and the energy capital costs are in the range of 954~3028 USD·kW^(-1)·h^(-1);in the cost breakdown,the highest cost of heat exchangers can reach up to 54%,the highest cost of thermal stores can reach up to 14%,and the costs of expanders and a compressor change in the range of 18%~31% and 14%~26%,respectively;compared with other system configurations,the recuperated Carnot battery system using Therminol as the storage material has the best economic performance.