Simulation Study on the Transient Operating Characteristics of Natural Circulation Coupled With PCM Energy Storage Module for the Passive Containment Cooling System

Abstract To achieve a further reduction in pressure peak during accidents, phase change materials (PCM) are utilized in conjunction with natural circulation in the passive containment cooling system (PCCS). The dynamic simulation model of PCCS has been developed using Apros software. This article focuses on a comparative analysis of cooling capacity, considering various thicknesses and types of PCM modules. The results indicate that employing a 4 mm PCM module decreases the pressure peak in the containment from 1.85 MPa to 1.68 MPa. Additionally, the impact of thickness on the maximum power of the heat exchanger is constrained by the lower thermal conductivity of the PCM. Another type of PCM with the same latent heat capacity but lower thermal conductivity maintains pressure peak suppression performance. However, it results in a diminished pressure drop performance during the continuous condensation of steam. As a consequence of increased accumulation of non-condensable gases at the bottom, the heat transfer for steam condensation at the corresponding position is impeded.