Exergoeconomic analysis of a novel trigeneration system based on organic quadrilateral cycle integrated with cascade absorption-compression system for waste heat recovery

摘要

The present research proposes a novel trigeneration system for cooling, heating, and power generation which is consisted of organic quadrilateral cycle (QLC) and cascade absorption compression system. The system is simulated and studied from energy, exergy, and exergoeconomic viewpoints. Cyclohexane, LiBr-H2O, and R410a are respectively used as working fluids for QLC, Absorption refrigeration system (ARS), and Compression refrigeration system (CRS) in the combined system. Using QLC instead of simple organic Rankine cycle (ORC) in the combined system makes it possible to generate electricity besides improvement of total system performance from energy and exergy viewpoints for the same input values. According to the base case results, the unit cost of electricity is 36.9 $/GJ and it has much less value compared with unit cost of heating and cooling which are equal to 101 $/GJ and 84.7 $/GJ, respectively. Therefore, more electricity production by employing QLC instead of ORC is economical. The results of system parametric analysis show that by variation of QLC expander inlet temperature and QLC condensation temperature while cooling rate decreases, the other output parameters such as output electricity, heating rate, exergy efficiency, and total cost rate improve. Selection of these two input parameters depends on demands. On the other hand, less ARS evaporation temperature and higher CRS evaporation temperature in the allowed range lead to better performance of the system.