Supply-storage collaborative flexible refrigeration system based on enhanced zeotropic mixture segregation cycle for power grid peak shaving

The large-scale integration of renewable energy generation poses significant challenges to power grid stability. The need to mitigate power grid load fluctuations from refrigeration systems has become urgent. However, conventional refrigeration systems based on the single-stage vapor compression cycle are designed to meet short-term cooling demands, which lack the ability for cold storage and flexible load adjustment. To address the above problems, a flexible refrigeration system is proposed in this study. The novel system is based on the enhanced zeotropic mixture segregation cycle to collaboratively achieve cold supply and cold storage at a single pressure. Additionally, the novel system leverages the temperature glide characteristics of the zeotropic mixture to reduce irreversible heat transfer losses. To evaluate the performance of the novel system, its thermodynamic properties are analyzed. Selecting the single-stage vapor compression chiller system as the comparative object, the feasibility of the novel system is analyzed. The results show that, compared with the conventional system, the annual operating cost of the novel system is reduced by 27%, and the life-cycle cost of the novel system is reduced by 11%.