Experimental Study and Optimization of the Organic Rankine Cycle with Pure NovecTM649 and Zeotropic Mixture NovecTM649/HFE7000 as Working Fluid

Abstract

The Organic Rankine Cycle (ORC) is widely used in industry to recover low-grade heat. Recently, some research on the ORC has focused on micro power production with new low global warming potential (GWP) replacement working fluids. However, few experimental tests have investigated the real performance level of this system in comparison with the ORC using classical fluids. This study concerns the experimental analysis and comparison of a compact (0.25 m3) Organic Rankine Cycle installation using as working fluids the NovecTM649 pure fluid and a zeotropic mixture composed of 80% NovecTM649 and 20% HFE7000 (mass composition) for low-grade waste heat conversion to produce low power. The purpose of this experimental test bench is to study replacement fluids and characterize them as possible replacement fluid candidates for an existing ORC system. The ORC performance with the pure fluid, which is the media specifically designed for this conversion system, shows good results as a replacement fluid in comparison with the ORC literature. The use of the mixture leads to a 10% increase in the global performance of the installation. Concerning the expansion component, an axial micro-turbine, its performance is only slightly affected by the use of the mixture. These results show that zeotropic mixtures can be used as an adjustment parameter for a given ORC installation and thus allow for the best use of the heat source available to produce electricity.

Development of a Fuzzy Logic Controller for Small-Scale Solar Organic Rankine Cycle Cogeneration Plants

“…The turbine isentropic efficiency varies with the operating conditions, and its values are based on the experimental data provided by the manufacturer ENOGIA [27]. In particular, under nominal operating conditions, the maximum isentropic efficiency is about 0.53, and it decreases with a pressure ratio, as better detailed in [28]. For the sake of the present analysis, a gear pump was considered to ensure the required refrigerant mass flow rate.…”

Process Systems Engineering Evaluation of Prospective Working Fluids for Organic Rankine Cycles Facilitated by Biogas Combustion Flue Gases

“…The ORCs have been studied extensively in the past decades. Several studies have evaluated working fluids (WFs) and ORC system configurations from a thermo-economic perspective (Imran et al, 2018;Blondel et al, 2019;Anastasovski et al, 2020). Mudasar et al (2017) studied a biogas-fueled high-temperature ORC (HT-ORC) system using toluene as the WF and reported that the maximum power generated and thermal efficiency were 156 kW and 19%, respectively.…”

Study of the integration of a supersonic impulse turbine in a NH3/H2O absorption heat pump for combined cooling and power production from a low temperature heat source

“…A di↵erent power generation technology is therefore investigated here, that of a partial admission action turbo-expander. The fact that in this type of expander all the expansion takes place in the distributor should limit the influence of leaking losses and guarantee a good level of work output [14]. However, due to the intrinsic behavior of the machine, special attention must be paid to the interdependence between the physics governing the expander and the cycle in which it is integrated.…”