Thermodynamic and economic investigation of geothermal powered absorption cooling system for buildings

Abstract

A geothermal powered absorption cooling system is considered for cooling of buildings. The system is analyzed by thermodynamic performance parameters such as cooling load and coefficient of performance (COP). An economic analysis of the system is performed to assess cost structure, potential revenues, payback periods and life cycle cost analysis. Effect of geothermal water temperature on the annual cooling cost and payback periods are investigated. A liquid geothermal source at a temperature of 100°C with a mass flow rate of 100kg/s is considered for İzmir city of Turkey. The COP of the ammonia-water absorption cycle is determined to be 0.441. The number of degree-days for the cooling season is calculated to be 1791°C and cooling load is calculated to be 12,870,000kWh by the DD (degree − days) method. The annual potential revenue of geothermal cooling is estimated to be 653,818 $/yr with simple and discounted payback periods of 5.684 and 8.816 years. The geothermal cooling is provided an annual monetary benefit of 166,610 $/yr on the entire lifetime of the system by the life cycle cost analysis. So, the unit product cooling cost is calculated to be 0.01295 $/kWh, respectively.