| 1. |
- Du, Banghua, et al.
(författare)
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Energy management and performance analysis of an off-grid integrated hydrogen energy utilization system
- 2024
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Ingår i: Energy Conversion and Management. - 0196-8904. ; 299
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Tidskriftsartikel (refereegranskat)abstract
- In integrated hydrogen energy utilization systems, due to the low efficiency of hydrogen/electricity conversion, coordination of energy management and efficient waste heat recovery is required to optimize performance. To address this challenge, this paper presents a comprehensive and sophisticated modeling and energy management strategy to enhance the off-grid energy utilization rate while prolonging the main components' lifetime. The developed model incorporates multiphase flow and heat transport balance for electricity and heat production, enabling a highly accurate representation of real-world behaviors of the system. The proposed off-grid operation strategy is complemented by a designed heat recovery scheme, ensuring the use of energy resources and waste heat. In addition, the proposed energy management strategy monitors the real-time status of each subsystem, actively reducing the number of harmful start-stop cycles of the hydrogen production system, thereby mitigating short-term power impacts and delaying its aging. Specifically, the voltage degradation of the reduction cell is reduced from 4.67 mV to 4.48 mV, the energy utilization rate is increased from 47.6 % to 53.9 %, and the energy efficiency of fuel cells significantly increases from 53.6 % to 78.1 %.
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| 2. |
- Zhu, Shihao, et al.
(författare)
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Design and optimization of a cascade hydrogen storage system for integrated energy utilization
- 2024
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Ingår i: Journal of Energy Storage. - 2352-152X. ; 96
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Tidskriftsartikel (refereegranskat)abstract
- In an integrated hydrogen energy utilization system, the hydrogen storage device needs to meet hydrogen supplies and demands of different pressure levels, traditional hydrogen storage systems will lead to more energy consumption and lower hydrogen supply efficiency. To address this problem, a cascade hydrogen storage system (CHSS) is proposed in this study. By configuring three hydrogen storage tanks (HSTs) with three pressure levels, the CHSS is capable of serving hydrogen for fuel cell supply, long-term storage, and refueling stations. The corresponding control strategy of hydrogen flow between HSTs is proposed. It shows that an optimal capacity configuration scheme with pressures of 3 MPa, 24.44 MPa, and 45 MPa and a hydrogen storage capacity of 401.7 kg, optimized by NSGA-II, can meet the stable operation of the system. Comparative studies show that the proposed CHSS configuration can reduce the cost by about 3.78 %, the energy consumption by about 6.92 %, and the hydrogen supply loss rate by about 12 % compared to the existing solutions under the tested conditions.
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