Cold energy system cascade analysis for waste cold energy recovery from liquid nitrogen

Abstract

Waste cold energy generated from liquid nitrogen vaporization is usually abandoned when the gas supply system is pre-designed without cold integration. This study aims to investigate the potential for energy savings in a chiller system through the integration of waste cold recovery with thermal energy storage. The cold waste recovery system captures the waste cold generated during the operation of the liquid bulk nitrogen system and transfers it to a thermal energy storage system. This stored energy can then be utilized to supplement the chiller system during the targeted periods of peak demand, reducing its load and increasing its efficiency. A time-based cascade analysis, i.e., Cold Energy System Cascade Analysis (CESCA), is developed to determine the maximum peak shave load with the minimum capacity of the TES for liquified nitrogen (LN2) cold energy recovery system for a given peak shaving duration. The proposed methodology is applied to 3 cases, with different peak shaving durations, to examine the impacts of peak shaving duration on the design of the LN2 cold energy recovery system.