Thermodynamic performance study of a combined cooling, heat and power system based on low temperature compression heat decomposing methanol on a combination of SOFC, CAES and ARC

A novel combined cooling, heating and power (CCHP) system based on low compression heat decomposing methanol on a combination of solid oxide fuel cell (SOFC), compressed air energy storage (CAES), and single effect NH3-H2O 3-H 2 O absorption refrigeration cycle (ARC) is proposed. In the new system, the low grade compression heat is converted into high grade chemical energy through low temperature compression heat decomposing methanol, which realizes high efficient use of low-grade compression heat. In addition, the ARC is integrated with stored low temperature compression heat to produce cooling. The energy, exergy and exergoeconomic analysis are carried out. The simulation results show the CCHP round-trip efficiency, electrical efficiency, exergy efficiency and discharging efficiency of the novel system reach 80.03 %,71.05 %,62.72 % and 75.94 %, respectively. Besides, the sensitivity analysis reveals the outlet pressure of compressed air energy tank (CAST) and methanol flow are main two parameters that affect system efficiencies. There always exit peak CCHP roundtrip efficiency and exergy efficiency with optimum outlet pressure of CAST of 0.8 MPa. For exergoeconomic analysis, the unit costs of power, heating and cooling are 39.72 $/GJ, 40.77 $/GJ and 96.27 $/GJ, respectively. In addition, the main devices with two highest exergoeconomic factors are GT (95 %) and reformer (92 %). In summary, the novel CCHP system realizes high efficient utilization of low temperature compression and provide theoretical basis for high efficient energy storage and conversion.