Electricity-Heat-Hydrogen Modeling of Hydrogen Storage System Considering Off-Design Characteristics

Yufeng Xiong,Shengwei Mei,Yang Si,Tianwen Zheng,Laijun Chen

doi:10.1109/access.2021.3130175

Abstract

With the advantages of zero carbon emission and multi-energy comprehensive utilization, hydrogen storage is the pivotal technology to help realize the goal of net-zero carbon and establish a new energy system. Combining the simple linear model and the complex mechanism model, this paper proposes an electricity-heat-hydrogen model of the hydrogen storage system considering off-design characteristics. In the proposed off-design hydrogen storage system (OD-HSS) model, critical operating variables like input power and electrolyte temperature are included to achieve a compromise between practicability and accuracy. Furthermore, the proposed OD-HSS model is applied to practical scheduling to verify its advantages in accuracy and practicality through the case studies. The results indicate that the proposed OD-HSS model managed to depict the efficiency changes under different circumstances, promote flexibility in heat storage, and lead to a more economical energy supply.

Highlights

U NDER the development goal of net-zero carbon, clean and low-carbon energy supply is becoming the primary development trend for the energy system [1]
Owing to the model of “fixing heat based on power” in the simple linear model, the heat power from the electrolytic cell and the fuel cell is independent of the heat purchase price, and determined by the hydrogen power or electrical power
To achieve a compromise between accuracy and practicality in the modeling of the Hydrogen storage system (HSS), this paper analyzed the offdesign characteristics of the electrolytic cell and the fuel cell and evaluated the influence of input power and electrolyte temperature on energy conversion efficiency

Summary

INTRODUCTION

U NDER the development goal of net-zero carbon, clean and low-carbon energy supply is becoming the primary development trend for the energy system [1]. The current simple linear model neglected the efficiency change under different operating conditions and flexible scheduling for heat supply and storage, while the complex mechanism model, featured with difficult form and restricted application, is incompetent to deal with the disadvantages above in practical scheduling To settle these problems, this paper pays attention to critical operating condition variables such as the input power and the electrolyte temperature and proposes the multi-energy model of the HSS considering the off-design characteristics. The temperature change of the fuel cell will influence the electrochemical characteristics curve and can be regulated to realized both-way heat exchange, similar to the electrolytic model Besides this neglection in the simple linear model, the nonlinear relationship between input power, output power, and electrolytic temperature is significant, which should be considered for accurate modeling. The OD-HSS model and the simple linear model are respectively used for optimal scheduling

ACCURACY EVALUATION OF THE OD-HSS MODEL

Findings

CONCLUSION