Performance analysis of the SOFC–CCHP system based on H₂O/Li–Br absorption refrigeration cycle fueled by coke oven gas

The CCHP (combined cooling, heating, and power) system, especially combined with the SOFC (solid oxide fuel cell), has great potential for improving energy utilization efficiency. Therefore an integrated SOFC–CCHP system, fueled by COG (coke oven gas) which contains large amount of hydrogen, has been designed and proposed in this paper. The flue gas exhausted from the HRSG (heat recovery steam generator) is used for heating and the latent heat of water exhausted from the ST (steam turbine) is used for cooling achieved by a single-effect lithium bromide absorption chiller. Based on the corresponding models, the evaluations of the system performance are carried out aided by Aspen Plus process simulator. The calculation results indicate that the electrical efficiency of the SOFC can reach over 60% while the total power efficiency and the overall system efficiency of SOFC–CCHP system are about 70% and 90% respectively. Furthermore, the effect of several operating parameters including fuel flow rate, hydrogen content of COG, fuel utilization factor and operating pressure are investigated and analyzed on the proposed system performance. This research lays a good foundation for the designing of the proposed integrated SOFC–CCHP system, which would be an efficient utilization option of COG. - Highlights: • This paper proposed a SOFC–CCHP system based on Li–Br absorption refrigeration cycle fueled by COG. • The modules models are established combining ASPEN PLUS and FORTRAN programming calculation. • For the co-generation system, the method for system performance evaluation was established. • This paper highlighted revealed the effects of the characteristics of COG on the performance of the integrated system. • From the view point of energy cascade utilization, the proposed integrated system is superior to the common similar systems.