A systematic method for performing pinch analysis of the Liquid Air Energy Storage (LAES) process

In process design, the insights obtained by applying pinch technology have played an important role in maximizing energy efficiency through energy integration [1]. Pinch technology exclusively addresses temperature variations in process streams resulting from indirect heat exchange. The analysis does not take into account temperature changes in process streams induced by changes in stream pressure. In this work, a systematic procedure for applying pinch analysis to the Liquid Air Energy Storage (LAES) process is proposed. In this process, air undergoes significant pressure changes, which results in phase changes as well as wide variations in the specific heat capacity. Since the air temperature varies from well above ambient to well below ambient conditions, multiple minimum approach temperature specifications have to be imposed. A parameterized version of the Grand Composite Curves (GCCs) is proposed for pinch analysis that takes into account for all of these special features. The parameterized GCCs are used to identify the feasible design space for a LAES process.