Mathematical model and investigation of a 300 MW cogeneration power plant based on the JIHT cycle operating under partial load conditions

Combined heat and power (CHP) plants require flexible operation to independently regulate electric and thermal output, yet achieving this across wide partial-load ranges remains a challenge. The JIHT cycle, utilizing oxygen combustion technology, offers a promising solution for CHP systems, but its operational feasibility under partial loads must be rigorously evaluated. To address this, a mathematical model is proposed in this paper for early-stage assessment of partial-load performance, enabling feasibility checks and efficiency estimates before component design. Application of the model to a 300 MW-rated plant demonstrates independent control of electric (120–360 MW) and thermal power (60–600 MW), with electrical efficiency reaching 48.5 % (nominal mode, higher heating value (HHV) basis). As the heat load increases, the electrical efficiency decreases, but the utilization factor increases, and with a heat to power ratio of 2, the utilization factor reaches 95 %.The results provide critical operational boundaries for key components of the plant, informing technical requirements for their design. This study confirms the JIHT cycle's viability for flexible CHP generation and offers a tool for optimizing system performance at the conceptual stage. © 2025 Elsevier B.V., All rights reserved.