An efficient trigeneration system based on a wet-ethanol fuelled HCCI engine for the production of power, heating, and cooling: Thermodynamic assessment

In this study, a comparative thermodynamic assessment was conducted for a trigeneration system driven by a wet-ethanol fueled HCCI engine, with the goal of meeting the energy needs (electricity, heating, and cooling) for various consumer demands in an environmentally sustainable manner. Utilizing the waste heat from HCCI engines through the Kalina cycle alongside the NH₃-H₂O based Absorption refrigeration cycle (ARC) and waste heat exchanger (WHE) makes it possible to produce power, cooling, and provide heating simultaneously. To examine the system performance, a comprehensive thermodynamic investigation based on energy and exergy balances are applied to this model. Additionally, a parametric investigation is also carried out to assess how some important different design parameters influence the useful outputs and performance of the proposed trigeneration system. The findings indicate that the HCCI engine achieved energy and exergy efficiencies of 41.59% and 34.29%, respectively, when waste heat was not utilized (i.e., without a bottoming cycle). However, with the effective use of waste heat from a wet-ethanol fuelled HCCI engine through the integration of the Kalina cycle, ARC cycle, and WHE, the overall system energy and exergy efficiencies were significantly enhanced to 51.49% and 39.28%, respectively. Additionally, the trigeneration system attains energy efficiencies of 44.64% for electricity, 4.94% for heating, and 1.91% for cooling under nominal operating conditions. Furthermore, the study identifies the key exergy destructive components within the proposed trigeneration system are the HCCI engine, catalytic converter, HRVG, and condenser 1, which exhibit exergy dissipation of 58.51%, 12.16%, 8.76%, and 6.12% respectively.