A Novel Exergy Indicator for Maximizing Energy Utilization in Low-Temperature ORC

Marcin Jankowski and Aleksandra Borsukiewicz
Additional contact information
Marcin Jankowski: ORC Power Plants Research and Development Centre, West Pomeranian University of Technology in Szczecin, al. Piastów 17, 70-310 Szczecin, Poland
Aleksandra Borsukiewicz: ORC Power Plants Research and Development Centre, West Pomeranian University of Technology in Szczecin, al. Piastów 17, 70-310 Szczecin, Poland

Energies, 2020, vol. 13, issue 7, 1-20

Abstract: In the last decade, particular attention has been paid to the organic Rankine cycle (ORC) power plant, a technology that implements a classical steam Rankine cycle using low-boiling fluid of organic origin. Depending on the specific application and the choice of the designer, the ORC can be optimized using one or several criteria. The selected objectives reflect various system performance aspects, such as: thermodynamic, economic, environmental or other. In this study, a novel criterion called exergy utilization index ( XUI ) is defined and used to maximize the utilization of an energy source in the ORC system. The maximization of the proposed indicator is equivalent to bring the heat carrier outlet temperature to the ambient temperature as close as possible. In the studied case, the XUI is applied along with the total heat transfer area of the system, and the multi-objective optimization is performed in order to determine the optimal operating conditions of the ORC. Moreover, to reveal a relationship between the XUI and important ORC performance indicators, a parametric study is conducted. Based on the results, it has been found that high values of the XUI (~80%) correspond to optimal values of exergy-based indicators such as: exergy efficiency, waste exergy ratio, environmental effect factor or exergetic sustainability index. Furthermore, the values of the XUI = 60%–80% are associated with beneficial economic characteristics reflected in a low payback period (<11.3 years). When considering the ecological aspect, the maximization of XUI has resulted in minimization of exergy waste to the environment. In general, the simple formulation and straightforward meaning make the XUI a particularly useful indicator for the preliminary evaluation and design of the ORC. Furthermore, the comparative analysis with respect to other well-known performance indicators has shown that it has a potential to be successfully applied as the objective function in the optimization of ORC power plants.

Keywords: ORC; multi-objective optimization; exergy; genetic algorithm; energy utilization (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2020
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (4)

Downloads: (external link)
https://www.mdpi.com/1996-1073/13/7/1598/pdf (application/pdf)
https://www.mdpi.com/1996-1073/13/7/1598/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:13:y:2020:i:7:p:1598-:d:339821

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().