Parametric Analysis of the Kalina Cycle

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.