Keywords: absorption refrigerators, variable-temperature heat reservoirs, four-temperature-level, finite time thermodynamics, thermodynamic modelling, irreversibilities, working fluids, heat leakages, cooling load, COP, coefficient of performance, heat resistance, thermal capacitance rates, refrigeration cycle
Thermodynamic modelling and performance of variable-temperature heat reservoir absorption refrigeration cycle
An irreversible variable-temperature heat reservoir four-temperature-level absorption refrigeration cycle model is established in this paper. The considered losses include heat resistances between heat reservoirs and working fluid, internal irreversibilities due to internal dissipation of the working fluid, and the heat leakages between the heat reservoirs and the surroundings. The general relationships between the cooling load and the COP are derived. Besides, the optimal performance characteristics between the cooling load and the COP are obtained using numerical examples. The effects of heat resistances, internal irreversibilities, heat leakages, and the thermal capacitance rates of heat reservoirs on the cycle performance are analysed.