Thermodynamic Analysis of Kalina Based Power and Cooling Cogeneration Cycle Employed Once Through Configuration

Abstract

The Kalina cycle (KC) has been considered one of the most efficient systems for harvesting low grade heat since its proposal and various modifications have been proposed. Recently, Kalina based power and cooling cogeneration cycles (KPCCCs) have attracted much attention and many studies have been conducted. In this paper, a cogeneration cycle of power and absorption refrigeration based on the Kalina cycle system 11 (KCS-11) is proposed. The cycle combines a KC and aqua-ammonia absorption refrigeration cycle (ABR) with once through configuration. Compared to the stand-alone KC, the proposed cycle showed significantly higher energy efficiency—as high as 60%—without the use of rectifier, superheater or subcooler. Parametric analysis showed that the ammonia fraction, separator pressure and source temperature have a significant impact on the system performance including mass flow rates, heat transfers, power generation, cooling capacity, energy efficiencies and optimum ammonia fraction for the maximum energy efficiency.

Keywords

• Kalina cycle
• power
• absorption refrigeration
• cogeneration
• low-grade heat source
• ammonia-water mixture
• efficiency