Dynamic Modeling and Comparison Study of Control Strategies of a Small-Scale Organic Rankine Cycle

The control strategy is crucial for the effective and safe operation of the ORC system. A transient model of the ORC system was developed in the present work and validated by the experimental data of a 4 kW ORC prototype. Then, the effect of heat source temperature on the dynamic response and operat...

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Main Authors: Yuhao Zhou, Jiongming Ruan, Guotong Hong, Zheng Miao
Format: Article
Language:English
Published: MDPI AG 2022-07-01
Series:Energies
Subjects:
Online Access:https://www.mdpi.com/1996-1073/15/15/5505
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author Yuhao Zhou
Jiongming Ruan
Guotong Hong
Zheng Miao
author_facet Yuhao Zhou
Jiongming Ruan
Guotong Hong
Zheng Miao
author_sort Yuhao Zhou
collection DOAJ
description The control strategy is crucial for the effective and safe operation of the ORC system. A transient model of the ORC system was developed in the present work and validated by the experimental data of a 4 kW ORC prototype. Then, the effect of heat source temperature on the dynamic response and operation characteristics of the ORC system were analyzed. Five control strategies were compared: the constant working fluid mass flow rate mode, constant vapor superheat mode, constant vapor temperature mode, constant evaporation pressure mode and constant output power load mode. Under the constraint that the working fluid at the expander inlet should be superheated, we found that the constant vapor superheat mode enabled the safe operation with the largest range of heat source temperature, while the other four modes were only available for a certain temperature range. Apart from the constant output power mode, the constant evaporation pressure mode can also provide a relatively stable performance for the ORC unit. The variation of the thermal efficiency was limited when the heat source temperature was higher than 125 °C, except for the constant vapor temperature mode. Considering the high performance and stable operation of the ORC system, it is necessary to have different operation modes combined in the control strategy according to the specific working scenarios.
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spelling doaj.art-4b5d1af4effe44fe879038a1eade07b42023-12-03T12:35:32ZengMDPI AGEnergies1996-10732022-07-011515550510.3390/en15155505Dynamic Modeling and Comparison Study of Control Strategies of a Small-Scale Organic Rankine CycleYuhao Zhou0Jiongming Ruan1Guotong Hong2Zheng Miao3Key Laboratory of Technology on Space Energy Conversion, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, ChinaHuadian Electric Power Research Institute Co., Ltd., Hangzhou 310030, ChinaKey Laboratory of Technology on Space Energy Conversion, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, ChinaBeijing Key Laboratory of Multiphase Flow and Heat Transfer for Low-Grade Energy Utilization, North China Electric Power University, Beijing 102206, ChinaThe control strategy is crucial for the effective and safe operation of the ORC system. A transient model of the ORC system was developed in the present work and validated by the experimental data of a 4 kW ORC prototype. Then, the effect of heat source temperature on the dynamic response and operation characteristics of the ORC system were analyzed. Five control strategies were compared: the constant working fluid mass flow rate mode, constant vapor superheat mode, constant vapor temperature mode, constant evaporation pressure mode and constant output power load mode. Under the constraint that the working fluid at the expander inlet should be superheated, we found that the constant vapor superheat mode enabled the safe operation with the largest range of heat source temperature, while the other four modes were only available for a certain temperature range. Apart from the constant output power mode, the constant evaporation pressure mode can also provide a relatively stable performance for the ORC unit. The variation of the thermal efficiency was limited when the heat source temperature was higher than 125 °C, except for the constant vapor temperature mode. Considering the high performance and stable operation of the ORC system, it is necessary to have different operation modes combined in the control strategy according to the specific working scenarios.https://www.mdpi.com/1996-1073/15/15/5505organic Rankine cycledynamic modelingcontrol strategyoutput powerthermal efficiency
spellingShingle Yuhao Zhou
Jiongming Ruan
Guotong Hong
Zheng Miao
Dynamic Modeling and Comparison Study of Control Strategies of a Small-Scale Organic Rankine Cycle
Energies
organic Rankine cycle
dynamic modeling
control strategy
output power
thermal efficiency
title Dynamic Modeling and Comparison Study of Control Strategies of a Small-Scale Organic Rankine Cycle
title_full Dynamic Modeling and Comparison Study of Control Strategies of a Small-Scale Organic Rankine Cycle
title_fullStr Dynamic Modeling and Comparison Study of Control Strategies of a Small-Scale Organic Rankine Cycle
title_full_unstemmed Dynamic Modeling and Comparison Study of Control Strategies of a Small-Scale Organic Rankine Cycle
title_short Dynamic Modeling and Comparison Study of Control Strategies of a Small-Scale Organic Rankine Cycle
title_sort dynamic modeling and comparison study of control strategies of a small scale organic rankine cycle
topic organic Rankine cycle
dynamic modeling
control strategy
output power
thermal efficiency
url https://www.mdpi.com/1996-1073/15/15/5505
work_keys_str_mv AT yuhaozhou dynamicmodelingandcomparisonstudyofcontrolstrategiesofasmallscaleorganicrankinecycle
AT jiongmingruan dynamicmodelingandcomparisonstudyofcontrolstrategiesofasmallscaleorganicrankinecycle
AT guotonghong dynamicmodelingandcomparisonstudyofcontrolstrategiesofasmallscaleorganicrankinecycle
AT zhengmiao dynamicmodelingandcomparisonstudyofcontrolstrategiesofasmallscaleorganicrankinecycle