Performance Evaluation of Series and Parallel Two-Stage Absorption Chillers by Using Solar Energy; Energetic Viewpoint

Document Type: Original Article


1 Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran

2 Department of Mechanical Engineering, Pardis Branch, Islamic Azad University, Pardis, Iran

3 Imam Khomeini International University Qazvin


In recent years, the use of absorption chillers in air conditioning applications has increased in favor of less power consumption. Due to the fact that absorption chillers require much less power compared to other common devices in the air conditioning industry, extensive efforts have been made in order to model, design, and optimize these systems. This study has investigated the effect of using solar energy on parallel and series two-stage refrigeration systems. First, both systems were designed, and then by connecting the solar collector to the equipment of absorption refrigeration system, the COP of the system and fuel consumption was calculated. Then, the impact of changing the evaporator’s temperature on the system’s COP were studied. The thermodynamic analysis of the system was conducted and the internal variables, such as pressure and temperature of different parts including the condenser and the evaporator, were calculated. Results indicate that the COP of the parallel cycle with a LiBr-H2O fluid is higher than that of a series cycle. As a result, this leads to a significant drop in fuel consumption.