Evaluation the Role of Multi-Stage Compression and Waste Heat Recovery on Compressed Air Energy Storage System Performance

2014 ◽  
Vol 492 ◽  
pp. 19-23
Author(s):  
Zuo Gang Guo ◽  
Guang Yi Deng ◽  
Pan Chu ◽  
Guang Ming Chen
Keyword(s):  
Energy Storage ◽  
Energy Conversion ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Heat Rate ◽  
Energy Conversion Efficiency ◽  
Compressed Air ◽  
Compression Process ◽  
Multi Stage

Compressed air energy storage (CAES) has the potential to improve the quality of renewable electricity from wind and solar. The non-continuous electricity from wind and solar can be stored in terms of compressed air energy, which can be released at peak time of state grid. In this paper, the influences of multi-stage compression and waste heat recovery on characteristic of CAES system were investigated. Results indicated that the adoption of multi-stage compression technology obviously reduced its heat rate, and the adoption of heat recovery improved its energy conversion efficiency. Among the three compression cases in this paper, the compression power consumed per kilogram air for the single-stage compression process was 890.83Kj/Kg, while which of the three-stage compression process with inter-cooler reduced to 524.82Kj/Kg. Meanwhile, the CAES system with three-stage compression and heat recovery had a low heat rate of 3974Kj/Kw.h and a high energy conversion efficiency of 59.92%.

scholarly journals Exergy analysis of the Szewalski cycle with a waste heat recovery system

2015 ◽  
Vol 36 (3) ◽  
pp. 25-48 ◽  
Author(s):  
Tomasz Kowalczyk ◽  
Paweł Ziółkowski ◽  
Janusz Badur
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Power Plants ◽  
Exergy Analysis ◽  
Waste Heat ◽  
Reference Conditions ◽  
Heat Rate ◽  
Working Fluid ◽  
Regeneration System ◽  
Waste Heat Recovery System

Abstract The conversion of a waste heat energy to electricity is now becoming one of the key points to improve the energy efficiency in a process engineering. However, large losses of a low-temperature thermal energy are also present in power engineering. One of such sources of waste heat in power plants are exhaust gases at the outlet of boilers. Through usage of a waste heat regeneration system it is possible to attain a heat rate of approximately 200 MWth, under about 90 °C, for a supercritical power block of 900 MWel fuelled by a lignite. In the article, we propose to use the waste heat to improve thermal efficiency of the Szewalski binary vapour cycle. The Szewalski binary vapour cycle provides steam as the working fluid in a high temperature part of the cycle, while another fluid – organic working fluid – as the working substance substituting conventional steam over the temperature range represented by the low pressure steam expansion. In order to define in detail the efficiency of energy conversion at various stages of the proposed cycle the exergy analysis was performed. The steam cycle for reference conditions, the Szewalski binary vapour cycle as well as the Szewalski hierarchic vapour cycle cooperating with a system of waste heat recovery have been comprised.

scholarly journals Optimal Design of Combined Two-Tank Latent and Metal Hydrides-Based Thermochemical Heat Storage Systems for High-Temperature Waste Heat Recovery

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4216 ◽  
Author(s):  
Serge Nyallang Nyamsi ◽  
Mykhaylo Lototskyy ◽  
Ivan Tolj
Keyword(s):  
Energy Storage ◽  
Melting Point ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Heat Storage ◽  
Waste Heat ◽  
Storage Systems ◽  
Storage System ◽  
Metal Hydrides ◽  
Thermochemical Heat Storage

The integration of thermal energy storage systems (TES) in waste-heat recovery applications shows great potential for energy efficiency improvement. In this study, a 2D mathematical model is formulated to analyze the performance of a two-tank thermochemical heat storage system using metal hydrides pair (Mg2Ni/LaNi5), for high-temperature waste heat recovery. Moreover, the system integrates a phase change material (PCM) to store and restore the heat of reaction of LaNi5. The effects of key properties of the PCM on the dynamics of the heat storage system were analyzed. Then, the TES was optimized using a genetic algorithm-based multi-objective optimization tool (NSGA-II), to maximize the power density, the energy density and storage efficiency simultaneously. The results indicate that the melting point Tm and the effective thermal conductivity of the PCM greatly affect the energy storage density and power output. For the range of melting point Tm = 30–50 °C used in this study, it was shown that a PCM with Tm = 47–49 °C leads to a maximum heat storage performance. Indeed, at that melting point narrow range, the thermodynamic driving force of reaction between metal hydrides during the heat charging and discharging processes is almost equal. The increase in the effective thermal conductivity by the addition of graphite brings about a tradeoff between increasing power output and decreasing the energy storage density. Finally, the hysteresis behavior (the difference between the melting and freezing point) only negatively impacts energy storage and power density during the heat discharging process by up to 9%. This study paves the way for the selection of PCMs for such combined thermochemical-latent heat storage systems.

Enhanced specific heat capacity of binary chloride salt by dissolving magnesium for high-temperature thermal energy storage and transfer

2017 ◽  
Vol 5 (28) ◽  
pp. 14811-14818 ◽  
Author(s):  
Heqing Tian ◽  
Lichan Du ◽  
Chenglong Huang ◽  
Xiaolan Wei ◽  
Jianfeng Lu ◽  
...  
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Industrial Waste ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Chloride Salt ◽  
Industrial Waste Heat ◽  
Significant Attention

Thermal energy storage and transfer technology has received significant attention with respect to concentrating solar power (CSP) and industrial waste heat recovery systems.

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