Simulation and parametric study on a novel modified Kalina cycle

Abstract

To improve the utilization rate of hot dry rock resources, it is necessary to recover the energy of geothermal tailwater and improve the net output work. An improved ammonia-water power cycle is proposed based on the Kalina cycle. Taking the geothermal parameters of the Husavik Power Plant in Iceland as the prototype (the water temperature of the geothermal well is 122 °C, and the tailwater temperature is 80 °C), the numerical simulation of the modified Kalina cycle is carried out by using Engineering Equation Solver software. The result shows that the net power output of the modified Kalina cycle increases by 10.5% compared to that of the Kalina cycle. In addition, the parametric study shows that the optimal ammonia concentration of the basic solution in the general area is 0.9. The lower the cooling water temperature is, the lower the turbine exhaust pressure and the higher the net power output. When the ammonia concentrations of the basic solution are 0.6, 0.7, 0.8 and 0.9, the optimum pressures are 29 bar, 36 bar, 41 bar and 45 bar, respectively. The results of this study will contribute to the utilization of geothermal energy in hot dry rock.