Research
on characterizing and optimizing heat-transfer capacity
(UA), an important design parameter determining separation
efficiency and energy consumption in heat-integrated air separation
columns (HIASC), is presented. The mathematical mechanism model of
HIASC is built first, then characteristics of UA are
explored. It is discovered that on one hand increasing of UA will lead to higher compressor load and thus brings higher
energy consumption; however on the other hand increasing of UA will benefit mass transfer and conversely reduces energy
consumption. For this reason, the optimal design on UA makes available the maximum energy efficiency together with considerable
savings of the equipment investment, which provides guidelines for
further designing of HIASC. Furthermore, an optimal partially coupled
structure of HIASC is developed to exploit energy saving potential
by lowering minimum temperature difference. The obtained optimization
results show that the optimal design of UA for a
fully coupled HIASC has achieved a 41.5% reduction in energy consumption
compared to conventional air separation columns (CASCs) and up to
46.9% energy reduction is achieved by applying the optimal partially
coupled design.