Low global warming potential (GWP) working fluids (WFs) for Organic Rankine Cycle (ORC) applications

Abstract

A great significance is attached to the Organic Rankine Cycles (ORCs) as heat recovery technologies and power generation from the low-temperature heat sources. These systems have been utilized in diverse applications since their first emergence in 1883. Working fluid (WF) selection exerts enormous influence over the performance of these cycles. A large variety of WFs has been historically tested in the ORCs, from the ordinary organic fluids to the nowadays hydrofluoro chemicals, to find compatible WFs for these systems. The current generation of the ORCs based on the international protocols needs low global warming potential (GWP) WFs to not only reduce their environmental impacts in the operation stage but also the whole life cycle of the system. This study aims to assess the performance of environmentally-friendly WFs in the ORCs through the literature. This paper firstly reviews screening methodologies and WF selection criteria to provide a better understanding of the WF selection procedure. Afterward, proposes three categories of WFs with a GWP value of lower than 150, including hydrocarbons (HCs), hydrofluoro chemicals, and mixture WF, and evaluates their performance in different configurations of the ORCs based on a variety of performance indicators.

Keywords

• Ozone depletion potential
• Energy, Efficiency. Organic Rankine Cycle
• Working fluids
• Global warming potential