A Novel Cascade Utilization System of Liquid Hydrogen Cold Energy: Energy, Exergy, and Economic Analysis

Abstract

In order to effectively improve the cold energy recovery efficiency and thermodynamic performance of liquid hydrogen regasification process, a novel type of liquid hydrogen cold energy cascade utilization (RC-HT-AS-DI-CS-AC) system is proposed, which includes Rankine cycle power generation (RC), hydrogen turbine power generation (HT), air separation (AS), production of dry ice (DI), cold storage (CS) and air conditioning (AC). A comprehensive energy, exergy and economic analysis is carried out to compare the proposed system with a comparison system scheme (CSS). For RC-HT-AS-DI-CS-AC system, the energy efficiency of overall system is 79.74%. The cold energy provided by the hydrogen stream achieve 182.31 kW, which is 61.18% increase compared with the CSS. The acquired exergy and exergy efficiency of the RC-HT-AS-DI-CS-AC system increase by 119.6% and 115.9% compared with the CSS. It reveals the importance of liquid hydrogen pressurization to improve exergy efficiency for overall system. However, in the economic analysis, the total annual cost (TAC) of the system of RC-HT-AS-DI-CS-AC system is 278,400 US $, which is significantly higher than TAC of CSS. As a result, the IRR of CSS and RC-HT-AS-DI-CS-AC systems are 87.39% and 15.10% respectively. Therefore, from a commercial point of view, CSS is more worthy of industrialization.