Hourly Performance Prediction of Solar Ejector-Absorption Refrigeration Based on Exergy and Exergoeconomic Concept

Abstract

Solar cooling technology is being increasingly studied due to its environmental compatibility and cost saving capability. In this article, application of solar absorption refrigeration for cooling of an office building is investigated through modeling and simulation. Solar radiation and cooling load demand have hourly modeled during summer days using Tehran’s climate data as a typical weather scenario. The simulation results show that from 9 AM to 5 PM, product cost per exergy unit ( c P,tot ) for the entire system decreases 87%. During this time, thermodynamic coefficient of performance ( COP th ) increases from 0.16 to 0.48 (auxiliary heat needed reduces from 4.36 to 1.23 kW), suggesting that the performance of the system increases until 5 PM. This is also confirmed by studying exergetic coefficient of performance ( COP exe ) which reaches to the maximum point at the same time. Furthermore summer days analysis shows that at maximum air temperature the system has optimal COPs while the minimum of c P,tot occurs at maximum radiation. The results show the exact times at which the system performs less efficiently by solar energy and therefore the opportunity of using other available renewable energy resources at these times.