Thermal economy simulation study for a carbon capture power plant with combined heat and power based on absorption heat pump technology

Abstract

The Combined Heat and Power (CHP) system represents an energy-efficient and environmentally-friendly approach to energy utilization. However, in the context of the “carbon peaking and carbon neutrality” strategy, ensuring low-carbon operation of CHP systems becomes imperative. In this study, based on absorption heat pump (AHP), an extraction condensing carbon capture (EC&CC) CHP coupled system and a low-pressure cylinder zero-output carbon capture (LCZ&CC) CHP coupled system are proposed, respectively. Furthermore, under the 100 % turbine heat acceptance (THA) operating condition, a variable operating condition study of heating load and carbon capture capacity is conducted. The results demonstrate that under identical heating load, the EC&CC CHP coupled system has superior thermal economy, with an average reduction of 1011.03 kJ/kWh in heat consumption of power generation and 34.54 g/kWh in coal consumption of power generation compared with the LCZ&CC CHP coupled system; For equivalent carbon capture capacity, the LCZ&CC CHP coupled system has superior thermal economy, with an average reduction of 771.28 kJ/kWh in heat consumption and 26.35 g/kWh in coal consumption of power generation compared with the EC&CC CHP coupled system. The EC&CC CHP coupled system has lower CO2 capture heat consumption, resulting in an average reduction of 135.67 t/h in carbon capture extraction compared with the LCZ&CC CHP coupled system. This study can provide guidance for optimizing the design of carbon capture CHP coupled systems.