Analysis of the thermodynamic performance of the organic Rankine cycle (ORC) based on the characteristic parameters of the working fluid and criterion for working fluid selection. (1st May 2020)

• Record Type: Journal Article
• Authors: Fan, Wei; Han, Zhonghe; Li, Peng; Jia, Yalei
• Is Part Of: Energy conversion and management. Volume 211(2020)
• Publication Date: 2020-05-01
• Subjects: Organic Rankine cycle -- Thermodynamic properties -- Characteristic parameters -- Working fluid -- Exergy efficiency; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2020.112746
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: Characteristic parameters reflect the thermal properties of working fluid in ORC. The effect of characteristic parameters on exergy efficiency of ORC is analysed. A criterion is established based on the characteristic parameters of working fluid. The criterion can distinguish the applicable range of different working fluids. The critical temperature has limitations in evaluating appropriate working fluid. Abstract: The objective of this paper is to establish a method for directly correlating the thermal properties of working fluid with the thermodynamic performance of ORC (organic Rankine cycle) to explore the effect of the thermal properties of working fluid on the thermodynamic performance of the cycle. On the basis of thermodynamic theory, the thermal properties of the working fluid in the ORC are abstracted into characteristic parameters, T s max, limiting temperature difference, B and C . Based on the characteristic parameters, x (feature function of the heat addition process), T - 1 (average temperature of heat addition), T - 2 (average temperature of heat rejection) and the exergy efficiency of 16 working fluids in the ORC are investigated. The results indicate that the change rules for T s max and critical temperature Tcr for different working fluids are generally the same. With the increase in Tg, out (temperature of the heat source medium at the evaporator outlet), although the increased evaporation temperature T 1 increases T - 1, decreased x values weaken the increase in the amplitude of T - 1 . The change rules for x and T - 1 for different working fluids are opposite at low Tg, out, while the same at high Tg, out . The transition temperature Tz, limiting temperature difference and Tcr are the main indicators for evaluating T - 1 of different working fluids. The change rules for T - 2 and B for the different working fluids are generally opposite, and B can be used as the criterion for working fluids with low T - 2 . The effects of T - 1 on exergy efficiency is stronger than that of T - 2, while the effect of T - 2 cannot be ignored at high Tg, out . The characteristic parameters of the working fluid explain the limitation of using Tcr as the criterion for working fluid selection, and establish the criterion for appropriate working fluid.