Experimental examination of the MoNiKa-ORC-Turbine and comparison of the results with thermodynamical calculation

The aim of this work is to understand the propane turbine behaviour located at MoNiKa facility in Campus North (KIT). Starting with the thermodynamic simulations, continuing with the selection of different load points to evaluate them experimentally on site and ending with the data analysis to finally reach the correction of the Stodola’s law equation and the turbine efficiency correction. The simulations were performed using GESI software developed in MATLAB® by ITES, and in addition, to perform these simulations, all the calculations of the thermodynamic properties were performed with the REFPROP software, NIST fluid properties database. The working medium of this work is either propane or a mixture between propane and nitrogen. The runs were carried out at the beginning of November 2021, where different types of assays were performed, previously analysed in GESI. First a test of different turbine load points was performed, the following day the response of the turbine was evaluated by progressively opening the turbine control valve and, the last day, another sensitivity test was performed, but this time the turbine was evaluated with the response of a progressive increase of the mass flow rate through the turbine. Stodola's equation provides a calculation method for the highly nonlinear dependence of the turbine inlet pressure with a flow for a multistage turbine with high backpressure. From its correction we find its behavior for this turbine. In turn, we sought to understand the dependence of the turbine efficiency, and an equation that solves it within certain boundary conditions. The current experiment performed during winter semester 2021/2022 and is the continuous work of previous thesis and experiments at the facility. Each test performed in MoNiKa brings the possibility to increase the know-how of the facility and optimize the performance of a Binary ORCs (supercritical organic Rankine cycle) power plant with a low temperature geothermal heat source.