Experimental study on the influence of the saline concentration in the electrical performance of a Hygroscopic cycle

Abstract The Hygroscopic cycle is a novel proprietary power cycle characterized by working with hygroscopic compounds which optimize the condensation of the turbine output steam in a steam absorber. This technology can be incorporated in any power plant that uses a Rankine cycle, obtaining higher electrical efficiency without limiting the cold sink temperature and without cooling water consumption. The novelty of this article is that Hygroscopic cycle is experimentally investigated in a test power plant with high concentrations of lithium bromide solution in water in the cooling reflux to analyze the effect on condensing temperature, condensing pressure, power output and efficiency. Mass concentration of lithium bromide in the cooling reflux stream ranges from 45 to 65%. The increase in salt concentration at the cooling reflux stream allows the condensing temperatures to be significantly increased by more than 15°C in a Hygroscopic cycle with respect to a Rankine cycle. Results also show that it is possible to decrease the turbine outlet condensing pressures for the same condensing temperature. Thereby, as mass concentration of lithium bromide is increased the gross electric power output increases with reference to a Rankine cycle for the same condensing temperature. The minimum increments in net electric power output and electrical efficiency are 7.6% and 2.6% respectively.