Study of two-stage ORC-plant energy efficiency

Nowadays increasing energy efficiency and introducing energy-saving technologies is a strategic task for all national economies. During various industrial processes a large amount of heat is released which is often utilized in cooling towers of various types or dissipated in the atmosphere. The paper presents a study of a two-stage ORC-installation with various working fluids of cascades which allows solving the problems of heat recovery at industrial enterprises effectively. The paper presents an analysis of the thermodynamic cycles of the primary and secondary circuits of a two-stage ORC plant for various working fluids, and also determines the thermodynamic parameters of the combined cycles of an ORC plant with different working fluids. Promising working fluids for the primary and secondary circuits of a two-stage ORC plant are proposed, the thermal efficiency of combined cycles is determined.