Optimization of performance under off-design conditions for dual-pressure organic Rankine cycle with hot source splitting

The Dual-Pressure Organic Rankine Cycle system, integrated with Hot Source Splitting (DORC-HSS), demonstrates enhanced performance by optimizing heat matching. A primary challenge in deploying the DORC-HSS system lies in its off-design performance, particularly when faced with varying conditions of...

Full description

Saved in:
Bibliographic Details
Main Authors: Shiqi Wang, Zhongyuan Yuan, Kim Tiow Ooi, Xiangyu Chang, Nanyang Yu
Format: Article
Language:English
Published: Elsevier 2025-03-01
Series:Energy Nexus
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2772427125000014
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832540434400804864
author Shiqi Wang
Zhongyuan Yuan
Kim Tiow Ooi
Xiangyu Chang
Nanyang Yu
author_facet Shiqi Wang
Zhongyuan Yuan
Kim Tiow Ooi
Xiangyu Chang
Nanyang Yu
author_sort Shiqi Wang
collection DOAJ
description The Dual-Pressure Organic Rankine Cycle system, integrated with Hot Source Splitting (DORC-HSS), demonstrates enhanced performance by optimizing heat matching. A primary challenge in deploying the DORC-HSS system lies in its off-design performance, particularly when faced with varying conditions of heat and cold sources. By using the first law of thermodynamics and the logarithmic mean temperature difference method, the MATLAB model of the system is established, and the net output power is optimized by particle swarm optimization. Our analysis reveals that in optimal off-design scenarios, the working fluid exits each loop preheater nearing a saturated liquid state. The increase in hot water flow rate leads to a decrease in the superheat degree in the high-pressure loop. Conversely, the working fluid at the expander inlet in the low-pressure loop consistently maintains a saturated vapor state. Furthermore, a 20.0% increase in optimal output power is observed for every 5 °C rise in hot water inlet temperature, and a 12.2% increase for every 20 kg/s increment in hot water flow rate. The highest thermal and exergy efficiencies achieved are 8.54% and 49.98%, respectively. A reduction of 1 °C in cooling water temperature corresponds to a 3.5% increase in output power. When the cooling water inlet temperature is 17 °C, the highest thermal and exergy efficiencies are 8.0% and 52.3%. The optimal hot water split ratio ranges from 67% to 79%. This optimization method can be used for any waste heat recovery system using DORC-HSS. Industries can approach control targets, ensuring the safe operation and translating into meaningful energy savings and lower operating costs. The economic benefits from such enhancements could shorten the payback period for DORC-HSS installations.
format Article
id doaj-art-fd9cfa6d1c804ae0a893cc3b52b58ae9
institution Kabale University
issn 2772-4271
language English
publishDate 2025-03-01
publisher Elsevier
record_format Article
series Energy Nexus
spelling doaj-art-fd9cfa6d1c804ae0a893cc3b52b58ae92025-02-05T04:32:49ZengElsevierEnergy Nexus2772-42712025-03-0117100360Optimization of performance under off-design conditions for dual-pressure organic Rankine cycle with hot source splittingShiqi Wang0Zhongyuan Yuan1Kim Tiow Ooi2Xiangyu Chang3Nanyang Yu4School of Mechanical Engineering, Southwest Jiaotong University, No. 111, North Section 1, 2nd Ring Road, Chengdu, 610031, China; School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, SingaporeSchool of Mechanical Engineering, Southwest Jiaotong University, No. 111, North Section 1, 2nd Ring Road, Chengdu, 610031, China; Corresponding author.School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, SingaporeSchool of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, SingaporeSchool of Mechanical Engineering, Southwest Jiaotong University, No. 111, North Section 1, 2nd Ring Road, Chengdu, 610031, ChinaThe Dual-Pressure Organic Rankine Cycle system, integrated with Hot Source Splitting (DORC-HSS), demonstrates enhanced performance by optimizing heat matching. A primary challenge in deploying the DORC-HSS system lies in its off-design performance, particularly when faced with varying conditions of heat and cold sources. By using the first law of thermodynamics and the logarithmic mean temperature difference method, the MATLAB model of the system is established, and the net output power is optimized by particle swarm optimization. Our analysis reveals that in optimal off-design scenarios, the working fluid exits each loop preheater nearing a saturated liquid state. The increase in hot water flow rate leads to a decrease in the superheat degree in the high-pressure loop. Conversely, the working fluid at the expander inlet in the low-pressure loop consistently maintains a saturated vapor state. Furthermore, a 20.0% increase in optimal output power is observed for every 5 °C rise in hot water inlet temperature, and a 12.2% increase for every 20 kg/s increment in hot water flow rate. The highest thermal and exergy efficiencies achieved are 8.54% and 49.98%, respectively. A reduction of 1 °C in cooling water temperature corresponds to a 3.5% increase in output power. When the cooling water inlet temperature is 17 °C, the highest thermal and exergy efficiencies are 8.0% and 52.3%. The optimal hot water split ratio ranges from 67% to 79%. This optimization method can be used for any waste heat recovery system using DORC-HSS. Industries can approach control targets, ensuring the safe operation and translating into meaningful energy savings and lower operating costs. The economic benefits from such enhancements could shorten the payback period for DORC-HSS installations.http://www.sciencedirect.com/science/article/pii/S2772427125000014Dual-pressure organic Rankine cycle (DORC)Hot source splitting (HSS)Off-design performanceHeat matching efficiency
spellingShingle Shiqi Wang
Zhongyuan Yuan
Kim Tiow Ooi
Xiangyu Chang
Nanyang Yu
Optimization of performance under off-design conditions for dual-pressure organic Rankine cycle with hot source splitting
Energy Nexus
Dual-pressure organic Rankine cycle (DORC)
Hot source splitting (HSS)
Off-design performance
Heat matching efficiency
title Optimization of performance under off-design conditions for dual-pressure organic Rankine cycle with hot source splitting
title_full Optimization of performance under off-design conditions for dual-pressure organic Rankine cycle with hot source splitting
title_fullStr Optimization of performance under off-design conditions for dual-pressure organic Rankine cycle with hot source splitting
title_full_unstemmed Optimization of performance under off-design conditions for dual-pressure organic Rankine cycle with hot source splitting
title_short Optimization of performance under off-design conditions for dual-pressure organic Rankine cycle with hot source splitting
title_sort optimization of performance under off design conditions for dual pressure organic rankine cycle with hot source splitting
topic Dual-pressure organic Rankine cycle (DORC)
Hot source splitting (HSS)
Off-design performance
Heat matching efficiency
url http://www.sciencedirect.com/science/article/pii/S2772427125000014
work_keys_str_mv AT shiqiwang optimizationofperformanceunderoffdesignconditionsfordualpressureorganicrankinecyclewithhotsourcesplitting
AT zhongyuanyuan optimizationofperformanceunderoffdesignconditionsfordualpressureorganicrankinecyclewithhotsourcesplitting
AT kimtiowooi optimizationofperformanceunderoffdesignconditionsfordualpressureorganicrankinecyclewithhotsourcesplitting
AT xiangyuchang optimizationofperformanceunderoffdesignconditionsfordualpressureorganicrankinecyclewithhotsourcesplitting
AT nanyangyu optimizationofperformanceunderoffdesignconditionsfordualpressureorganicrankinecyclewithhotsourcesplitting