Techno-Economic Analysis of dual ejectors solar assisted combined absorption cooling cycle

Abstract

This paper deals with the Techno-Economic Analysis of dual ejectors –flash tank absorption cooling cycle assisted by solar energy. In this study, the solar system is simulated using the TRNSYS software and a one-dimensional ejector is modeled in EES (Engineering Equation Solver) using NH3/H2O as working fluids. A cooling capacity of 5 kW is considered and a parametric optimization is carried out to select the optimum size of the thermal solar system. The design of the absorption cooling cycle under the Malaysia climate conditions was 5 kW (about 1.5 refrigeration ton) with a solar thermal collector (evacuated tube solar collector of 8.5 m2 sloped at 14° and 0.35 m3 tank size with 0.1 kg s−1 for fluid flow rate). The solar fraction varied between 53.6% in March and 68.6% in February. The payback period and profit gain for the dual ejector cycle, flash –tank with ejector and basic cycle with only ejector are 11 yr, 3192 $; 13.5yr, 1647$; and 16 yr, 874$ respectively. The results also show that the combined dual ejectors-flash tank cycle (Cycle 3) was up to 27% less than of the absorption combined ejector system (Cycle -1), and 10% cheaper than the combined ejector –flash tank absorption system (Cycle -2). Therefore, the economic analysis showed that the absorption system with dual ejectors (Cycle -3) was the preferred option.

Keywords

• Ejector-flash tank absorption cooling cycle
• Double ejectors
• Techno-economical analysis
• Cycle performance