Parametric Analysis of the Kalina Cycle

TLDR

The Kalina Cycle employs an ammonia‑water mixture, exploiting ammonia’s lower boiling point to better match the enthalpy–temperature curve of hot gas sources and enabling composition‑dependent condensation and heat input for improved performance. Computer models optimized a simplified cycle and compared it to a more complex version by El‑Sayed and Tribus, developing a balancing method and identifying key optimization parameters. The balancing method and identified key parameters enhance cycle optimization, confirming the simplified model’s effectiveness.

Abstract

The Kalina Cycle utilizes a mixture of ammonia and water as the working fluid in a vapor power cycle. When the liquid mixture is heated the more volatile ammonia tends to vaporize first and at a lower temperature than does pure water. This property of ammonia-water mixtures makes possible a better match to the enthalpy-temperature curve of a hot gas heat source such as a gas turbine exhaust and also permits circulation of fluids of different composition in different parts of the cycle. Taking advantage of the latter feature, condensation (absorption) can be done at slightly above atmospheric pressure with a low concentration of ammonia, while heat input is at a higher concentration for optimum cycle performance. Computer models have been used to optimize a simplified form of the cycle and to compare results for a more complex version proposed by El-Sayed and Tribus. A method of balancing the cycle was developed and key parameters for optimizing the cycle identified.