Coupled cooling method for multiple latent heat thermal storage devices combined with pre-cooling of envelope: Model development and operation optimization

Efficient latent heat thermal energy storage (LHTES) systems can be potentially employed to improve the energy saving capability and thermal performance of buildings. In this paper, a new coupled cooling method with phase-change chairs (PCC) and phase-change plates (PCPs) is firstly proposed to solve the cooling problem in isolated environments, such as mine refuge chamber with high temperature. A mathematical model of the new coupled cooling system is developed, validated, and applied to evaluate the heat transfer, temperature control effect, and operation optimization. The results show that when the number of PCPs is increased from 180 to 260, the proposed system helps decrease room temperature by 0.3 °C. For every 1 °C increase in melting temperature or for 1 °C decrease in cold storage temperature, the room temperature increases by 0.5 °C. Compared to the coupled cooling method with PCP alone, the proposed system leads to a temperature reduction of 1.4 °C in the first 50 h, while the volume occupied by the cooling system is reduced by 31.4%. Therefore, the technical proposal of combining PCC and PCP is recommended to further improve the indoor thermal comfort and reduce the occupied space without significant utilization of the phase-change materials (PCM).