Economic assessment and LCCP evaluation of air-cooled module chiller system with thermal energy storage

An absorption chiller and water-cooled chiller are commonly used for heating and cooling of medium-sized buildings. These systems generally have at least 50 RT or more capacity and have difficulty in handling various design capacities. Recently, an air-cooled module chiller has attracted much attention as an alternative system because of its ability to expand the capacity up to 320 RT by combining small units into modules. Combining the air-cooled module chiller system with the thermal energy storage can reduce energy cost and power consumption during peak load period in summer using cheap night-time power. The objective of this study is to conduct the economic assessment and LCCP evaluation of the absorption chiller system and the air-cooled module chiller system with the thermal energy storage for office and hospital buildings. The results showed that the total annual cost decreased with the decrease in the storage tank capacity owing to the reduced the initial investment cost. Comparing the total annual cost of the systems for the office and hospital, the total annual cost of the hospital was significantly higher than that of the office. However, the total annual cost of the hospital was reduced similar to that of the office under air-cooled module chillers with 50% thermal energy storage. In the LCCP analysis, total CO₂ emissions were decreased with the decrease in the storage tank capacity owing to the reduced direct emissions from refrigerant leakage.