Abstract
Modern cold storages hint towards the need of sustainable and economical cooling technologies, where ice-batteries as Phase Changing Materials (PCMs) show greater potential as effective and affordable means of Thermal Energy Storage (TES) systems in both residential and industrial areas. Conventional cooling units operating on vapor compression cycles are energy intensive and are heavy on energy bills. Ice-batteries have a great potential to passively store and release large volumes of thermal energy at different demand and supply intervals. This allows shifting the load towards lower ambient temperature periods where the operating efficiencies are comparatively higher i.e., during the night time. The presence of electricity tariff differential for peak and off-peak periods within a day is also a major assist in saving operational cost through load shifting. Cold storages that make use of active cooling systems are the most suited scope of commercial application for phase changing ice-batteries. The aim of such integration is to reduce cooling loads on already available air conditioning units and effectively tackle infiltration in the storage. This paper makes a theoretical approach towards the working model of a cold storage system integrated with multiple units of ice-batteries to shift the peak load by following the principles of night ventilation. This was solely done through analytical methods following thermodynamics of a generalized cold storage system and on its basis, mathematical equations were derived. The equations obtained from the model were then put into Python and the operational parameters were fed as input. The output was received in terms of sensitivity analysis of the dependence of cost saving with varying operational parameters. Numerical validation was done through comparison of results with other literatures with similar themes. Results show saved operational cost and shorter payback periods on investment upon integration of ice-batteries. Though the outcomes are system specific, the generalized model shows the prospects of saving up to 30% in daily energy consumption and receiving a payback up to NRs 55,000 annually depending upon the parameters involved, making application of this model a feasible prospect.
Full Paper: https://www.researchgate.net/publication/394986523_Integrating_Ice_Batteries_as_TES_Systems_in_Cold_Storages_to_Shift_Load_Towards_Off-peak_Period_A_Theoretical_and_Numerical_Approach