Thermodynamic analysis of Kalina cycle configurations for utilisation of geothermal energy

Abstract

Numerical study of Kalina cycle based power generating systems has been presented to utilise low temperature geothermal heat source. Computer codes have been developed in MATLAB to evaluate the thermal properties of working fluid. The performance of systems has been analysed considering the operating parameters that suit Indian climatic conditions. Parametric analyses of the Kalina cycle configurations have been presented showing the effect of key parameters on system performance. The efficiency of low temperature Kalina cycle system is noted to be 12.95% operating at 145oC. The cycle efficiency has improved by 2% with the incorporation of an auxiliary superheater in the system. The incorporation of an auxiliary separator increases NH3 concentration in the vapour mixture and enables operation of the system at reduced pressure. Further, a combined system has been designed that produces electricity and cooling effect simultaneously. The combined cycle shows gain in thermal efficiency by 6%.