Numerical simulation of an advanced energy storage system using H2O–LiBr as working fluid, Part 2: System simulation and analysis

2007 ◽  
Vol 30 (2) ◽  
pp. 364-376 ◽  
Author(s):  
S.M. Xu ◽  
C.H. Xu ◽  
L. Zhang ◽  
J. Liang ◽  
R. Du
Keyword(s):  
Numerical Simulation ◽  
Energy Storage ◽  
System Simulation ◽  
Storage System ◽  
Energy Storage System ◽  
Working Fluid

scholarly journals CFD-subset-FVM-based MATLAB-simulation of Heat Transfer in High Grade Cold Storage Augmenting Cryogenic Energy Storage System by Circulating Natural Gas as Working Fluid

2019 ◽  
Vol 8 (12) ◽  
pp. 3148-3150
Keyword(s):  
Energy Storage ◽  
Natural Gas ◽  
Cold Storage ◽  
Waste Heat ◽  
Storage System ◽  
Thermodynamic Cycle ◽  
Energy Storage System ◽  
Working Fluid ◽  
High Grade ◽  
Power Sources

Cryogenic Energy Storage (CES) improves power grid application with renewable intermittent power sources. In CES, off-peak excess electricity liquefies air or natural gas. Cryogenic fluid so obtained is stored in large Dewar tanks for long periods of time. Whenever electricity need is in peak, work available in cryogen is recovered by thermodynamic cycle using hot storage waste heat (HSWH) that has been generated by liquefier’s compressor. Many researchers focus on liquid air energy storage (LAES). But, natural gas (NG) is good working substance for CES liquefaction process. This paper reviews NG-CES containing high grade cold storage (HGCS). Cold stored HGCS is utilized to raise CES efficiency and hike liquefier yield. This paper models HGCS unit and compares output with experimental data. Impact of cold recycling is analyzed for liquefier yield and storage efficiency.

Second Law Analysis of an Energy Storage System Consisting of an Electrolysis Plant and the Graz Cycle With Internal H2/O2 Combustion

2019 ◽  
Author(s):  
Simeon Dybe ◽  
Tom Tanneberger ◽  
Panagiotis Stathopoulos
Keyword(s):  
Energy Storage ◽  
Power Plants ◽  
Storage System ◽  
Electric Energy ◽  
Energy Storage System ◽  
Working Fluid ◽  
Energetic Efficiency ◽  
Second Law ◽  
Electric Energy Storage ◽  
Second Law Analysis

Abstract The expansion of renewable energy generation must go hand in hand with measures for reliable energy supply and energy storage. A combination of hydrogen and oxygen as storing media provided from electrolysis at high pressure and zero emission power plants is a very promising option. The Graz cycle is an oxy-fuel combined power cycle that can operate with internal H2/O2 combustion and steam as working fluid. It offers thermal efficiencies up to 68.5% (LHV). This work applies a second law analysis to the Graz cycle and determines its exergetic efficiency. Exergy destruction is broken down to the cycle’s components thus providing insights on the location and magnitude of the cycle’s inefficiencies. A sensitivity analysis identifies the cycle’s exergetic and energetic efficiency as a function of representative parameters, offering an approach for future improvements. The combination of the cycle with an electrolysis plant is subsequently analyzed as an electric energy storage system. The round trip efficiency of the storage and back conversion system is computed by taking into account the additional compression of the reactants. As part of this analysis, the effect of the electrolyzer’s operational pressure is studied by comparing several commercial electrolyzers.

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