【目的】针对日尺度电网负荷周期性波动导致的源-荷失衡问题,研究压缩空气储能(compressed air energy storage,CAES)系统中喷射器的性能优化方法,以提升系统整体能效与运行调控能力。在CAES系统中,喷射器兼具调节空气参数与引射低压乏...【目的】针对日尺度电网负荷周期性波动导致的源-荷失衡问题,研究压缩空气储能(compressed air energy storage,CAES)系统中喷射器的性能优化方法,以提升系统整体能效与运行调控能力。在CAES系统中,喷射器兼具调节空气参数与引射低压乏气的双重功能,其工作性能对系统效率具有重要影响。【方法】以某在建10 MW级CAES示范系统为研究对象,结合响应面法与CFD软件数值模拟,分析喷射器在变压运行条件下的性能特性,确定其高效工作区间;进一步基于性能结果和释能变压力特性设计储气罐容积,并预测系统发电能力。【结果】喷射器的引射性能对工作气体压力与引射乏气压力变化敏感,在工作气体压力为10.00~11.75 MPa、引射乏气压力为5.6 MPa时,喷射器的引射性能表现最优。喷射器的出口背压对其内部的流场结构与CAES系统的运行工况影响显著。当背压为8.0 MPa时,喷射器在工作压力为12.00~10.00 MPa时高效运行,能量利用率最高达10.46%;配置2.2×10^(3) m^(3)储气罐的CAES系统在背压8.0 MPa条件下,能够以设计功率持续运行4.0 h,其能量转化率为16.67%,释能发电量累计达5.01×10^(4) kW·h,较无喷射器系统提升2.04%。【结论】通过明确喷射器高效运行区间并合理配置储气罐容积,可有效提高CAES系统发电效益,为工程实际中的系统优化与运行策略制定提供依据。展开更多
Development of high performance,flexible piezoelectric nanogenerators(PENGs)is critical for advancing self-powered sensing and microelectronic applications.In this study,a hydrogen-bond substitute strategy was employe...Development of high performance,flexible piezoelectric nanogenerators(PENGs)is critical for advancing self-powered sensing and microelectronic applications.In this study,a hydrogen-bond substitute strategy was employed to fabricate a multi-layer PENG based on a cellulose/polyvinylidene fluoride(PVDF)blend film matrix,incorporating multi-phase BCZT(0.1BaZr_(0.2)Ti_(0.8)O_(3)-0.9Ba_(0.7)Ca_(0.3)TiO_(3))ceramic fillers.Structural characterization via SEM and TEM revealed that an intricate hydrogen-bond network facilitated the uniform dispersion of ceramic fillers within the composite film’s sub-layers.In order to study the effect of filler distribution on piezoelectric performance,the single-and double-layer composite films with varying BCZT configurations were produced and evaluated.The results demonstrated that double-layer PENGs exhibit significantly enhanced electrical output compared to their single-layer counterparts,with the D-L_(3)H_(7) configuration achieving an open circuit voltage(V_(OC))of 23.13 V and a short circuit current(I_(SC))of 8.32μA.This enhancement is attributed to increased inter-layer interfaces,which effectively suppressed charge injection and migration,leading to improved charge density.Additionally,the presence of sharp tipped hexagonal tetragonal phase nanoparticles induced an electric field enhancement effect,further optimizing performance.展开更多
基金National Natural Science Foundation of China(52472132)Opening Project of Engineering Research Center of Eco-friendly Polymeric Materials,Ministry of Education(EFP-KF2403)Innovation Service Capability Support Plan of Xianyang(Science and Technology Innovation Talents)。
文摘Development of high performance,flexible piezoelectric nanogenerators(PENGs)is critical for advancing self-powered sensing and microelectronic applications.In this study,a hydrogen-bond substitute strategy was employed to fabricate a multi-layer PENG based on a cellulose/polyvinylidene fluoride(PVDF)blend film matrix,incorporating multi-phase BCZT(0.1BaZr_(0.2)Ti_(0.8)O_(3)-0.9Ba_(0.7)Ca_(0.3)TiO_(3))ceramic fillers.Structural characterization via SEM and TEM revealed that an intricate hydrogen-bond network facilitated the uniform dispersion of ceramic fillers within the composite film’s sub-layers.In order to study the effect of filler distribution on piezoelectric performance,the single-and double-layer composite films with varying BCZT configurations were produced and evaluated.The results demonstrated that double-layer PENGs exhibit significantly enhanced electrical output compared to their single-layer counterparts,with the D-L_(3)H_(7) configuration achieving an open circuit voltage(V_(OC))of 23.13 V and a short circuit current(I_(SC))of 8.32μA.This enhancement is attributed to increased inter-layer interfaces,which effectively suppressed charge injection and migration,leading to improved charge density.Additionally,the presence of sharp tipped hexagonal tetragonal phase nanoparticles induced an electric field enhancement effect,further optimizing performance.
