Open Access

ARTICLE

Thermo-Economic Performance Comparison between Basic Organic Rankine Cycle and Organic Rankine Cycle with Vapor-Liquid Ejector Driven by Solar Energy

Lingbao Wang^1,2, Zhi Gan², Zuowei Yang^3,*, Huashan Li^1,2, Yulie Gong^1,2, Xianbiao Bu^1,2

1 School of Energy Science and Engineering, University of Science and Technology of China, Guangzhou, 510640, China
2 Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou, 510640, China
3 Industrial Turbine Division, Dongfang Turbine Co., Ltd., Deyang, 618000, China

* Corresponding Author: Zuowei Yang. Email:

(This article belongs to the Special Issue: Recent Advance and Development in Solar Energy)

Energy Engineering 2025, 122(4), 1443-1468. https://doi.org/10.32604/ee.2025.060113

Received 24 October 2024; Accepted 31 January 2025; Issue published 31 March 2025

Abstract

Amidst the global push for decarbonization, solar-powered Organic Rankine Cycle (SORC) systems are gaining significant attention. The small-scale Organic Rankine Cycle (ORC) systems have enhanced environmental adaptability, improved system flexibility, and achieved diversification of application scenarios. However, the power consumption ratio of the working fluid pump becomes significantly larger relative to the total power output of the system, adversely impacting overall system efficiency. This study introduces an innovative approach by incorporating a vapor-liquid ejector into the ORC system to reduce the pump work consumption within the ORC. The thermo-economic models for both the traditional ORC and an ORC integrated with a vapor-liquid ejector driven by solar parabolic trough collectors (PTCs) were developed. Key evaluation indicators, such as thermal efficiency, exergy efficiency, specific investment cost, and levelized cost of energy, were employed to compare the SORC with the solar ejector organic Rankine cycle (SEORC). Additionally, the study explores the effects of solar beam radiation intensity, PTC temperature variation, evaporator pinch point temperature difference, and condenser pinch point temperature difference on the thermo-economic performance of both systems. Results demonstrate that SEORC consistently outperforms SORC. Higher solar radiation intensity and increased PTC inlet temperature lead to better system efficiency. Moreover, there is an optimal PTC temperature drop where both thermal and exergy efficiencies are maximized. The influence of evaporator and condenser temperature pinches on system performance is found to be inconsistent.

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Keywords

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