Modeling and Off-Design Prediction of an Organic Rankine Cycle

Abstract: The background for this master thesis project is a problem to describe performance of a small 150 kW organic Rankine cycle power plant. Climeon AB in Kista, has developed the unit, and the product is currently in use at different customers. The ”HP150” unit is made with a modular approach. It is a factory made box-shaped unit which is able to be installed at a variety of sites. The aim of this project was to create a numerical program to calculate the performance for a variation of off-design conditions. The general method has been to use design parameters and describe components individually. The computer model of the machine has then been arranged as close to the real thermodynamic cycle as possible. The program has logical and numerical methods, in order to find the maximum theoretical power output for the machine. The result seems to show that the model is consistent and in some range accurate with an error in output power below 5%. So the program has potential to be useful in the pursuit of estimating power output for various operating conditions.