Selecting the configuration of inter-stage coolers for a CO2 compressor

Abstract

The compression process is one of the most energy-consuming stages of the entire cycle of the carbon dioxide captureand storage. a reduction in the energy consumption of this process may have a significant impact on the overall neteciency of electricity generation. One method to improve the eciency of the compression process is to introduceinter-stage cooling, which makes it possible to cause compression to resemble an isothermal process. This paper presentsan analysis of the operation of a cooling system of an eight-stage integrally geared compressor working for a 900 MWcoal-fired power plant equipped with a CCS system. The research conducted enables rational values of the heat transfercoecient to be determined for individual inter-stage coolers. a series of calculations is performed in this analysisfor dierent assumptions and for an assumed geometry of the inter-stage coolers. The results obtained allow one todetermine both the heat exchange surface area and the pressure drops on the “hot” and “cold” agent sides for individualcoolers. Moreover, the presented analysis identifies a number of problems that arise when selecting the configurationand the appropriate parameters of the cooling system.