Impact of the Regulation Strategy on the Transient Behavior of a Brayton Heat Pump
High-temperature heat pumps are a key technology for enabling the complete integration of renewables into the power grid. Although these systems may come with several variants, Brayton heat pumps are gaining more and more interest because of the higher heat sink temperatures and the potential to lev...
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-02-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/17/5/1020 |
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| author | Matteo Pettinari Guido Francesco Frate A. Phong Tran Johannes Oehler Panagiotis Stathopoulos Konstantinos Kyprianidis Lorenzo Ferrari |
| author_facet | Matteo Pettinari Guido Francesco Frate A. Phong Tran Johannes Oehler Panagiotis Stathopoulos Konstantinos Kyprianidis Lorenzo Ferrari |
| author_sort | Matteo Pettinari |
| collection | DOAJ |
| description | High-temperature heat pumps are a key technology for enabling the complete integration of renewables into the power grid. Although these systems may come with several variants, Brayton heat pumps are gaining more and more interest because of the higher heat sink temperatures and the potential to leverage already existing components in the industry. Because these systems utilize renewable electricity to supply high-temperature heat, they are particularly suited for industry or energy storage applications, thus prompting the development of various demonstration plants to evaluate their performance and flexibility. Adapting to varying load conditions and swiftly responding to load adjustments represent crucial aspects for advancing such systems. In this context, this study delves into assessing the transient capabilities of Brayton heat pumps during thermal load management. A transient model of an emerging prototype is presented, comprising thermal and volume dynamics of the components. Furthermore, two reference scenarios are examined to assess the transient performance of the system, namely a thermal load alteration due to an abrupt change in the desired heat sink temperature and, secondly, to a sudden variation in the sink mass flow rate. Finally, two control methodologies—motor/compressor speed variation and fluid inventory control—are analyzed in the latter scenario, and a comparative analysis of their effectiveness is discussed. Results indicate that varying the compressor speed allows for a response time in the 8–20 min range for heat sink temperature regulation (first scenario). However, the regulation time is conditioned by the maximum thermal stress sustained by the heat exchangers. In the latter scenario, regulating the compressor speed shows a faster response time than the inventory control (2–5 min vs. 15 min). However, the inventory approach provides higher COPs in part-load conditions and better stability during the transient phase. |
| first_indexed | 2024-04-25T00:31:12Z |
| format | Article |
| id | doaj.art-75091b2ec174407ab76223e541e7dc41 |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-25T00:31:12Z |
| publishDate | 2024-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-75091b2ec174407ab76223e541e7dc412024-03-12T16:43:02ZengMDPI AGEnergies1996-10732024-02-01175102010.3390/en17051020Impact of the Regulation Strategy on the Transient Behavior of a Brayton Heat PumpMatteo Pettinari0Guido Francesco Frate1A. Phong Tran2Johannes Oehler3Panagiotis Stathopoulos4Konstantinos Kyprianidis5Lorenzo Ferrari6Department of Energy, Systems, Territory and Construction Engineering, University of Pisa, 56122 Pisa, ItalyDepartment of Energy, Systems, Territory and Construction Engineering, University of Pisa, 56122 Pisa, ItalyInstitute of Low-Carbon Industrial Processes, German Aerospace Center (DLR), 03046 Cottbus, GermanyInstitute of Low-Carbon Industrial Processes, German Aerospace Center (DLR), 03046 Cottbus, GermanyInstitute of Low-Carbon Industrial Processes, German Aerospace Center (DLR), 03046 Cottbus, GermanyDepartment of Sustainable Energy Systems, School of Business, Society and Engineering, Mälardalen University, 72123 Västerås, SwedenDepartment of Energy, Systems, Territory and Construction Engineering, University of Pisa, 56122 Pisa, ItalyHigh-temperature heat pumps are a key technology for enabling the complete integration of renewables into the power grid. Although these systems may come with several variants, Brayton heat pumps are gaining more and more interest because of the higher heat sink temperatures and the potential to leverage already existing components in the industry. Because these systems utilize renewable electricity to supply high-temperature heat, they are particularly suited for industry or energy storage applications, thus prompting the development of various demonstration plants to evaluate their performance and flexibility. Adapting to varying load conditions and swiftly responding to load adjustments represent crucial aspects for advancing such systems. In this context, this study delves into assessing the transient capabilities of Brayton heat pumps during thermal load management. A transient model of an emerging prototype is presented, comprising thermal and volume dynamics of the components. Furthermore, two reference scenarios are examined to assess the transient performance of the system, namely a thermal load alteration due to an abrupt change in the desired heat sink temperature and, secondly, to a sudden variation in the sink mass flow rate. Finally, two control methodologies—motor/compressor speed variation and fluid inventory control—are analyzed in the latter scenario, and a comparative analysis of their effectiveness is discussed. Results indicate that varying the compressor speed allows for a response time in the 8–20 min range for heat sink temperature regulation (first scenario). However, the regulation time is conditioned by the maximum thermal stress sustained by the heat exchangers. In the latter scenario, regulating the compressor speed shows a faster response time than the inventory control (2–5 min vs. 15 min). However, the inventory approach provides higher COPs in part-load conditions and better stability during the transient phase.https://www.mdpi.com/1996-1073/17/5/1020high-temperature heat pumpBrayton heat pumpdynamic modelingtransient simulationcontrol system |
| spellingShingle | Matteo Pettinari Guido Francesco Frate A. Phong Tran Johannes Oehler Panagiotis Stathopoulos Konstantinos Kyprianidis Lorenzo Ferrari Impact of the Regulation Strategy on the Transient Behavior of a Brayton Heat Pump Energies high-temperature heat pump Brayton heat pump dynamic modeling transient simulation control system |
| title | Impact of the Regulation Strategy on the Transient Behavior of a Brayton Heat Pump |
| title_full | Impact of the Regulation Strategy on the Transient Behavior of a Brayton Heat Pump |
| title_fullStr | Impact of the Regulation Strategy on the Transient Behavior of a Brayton Heat Pump |
| title_full_unstemmed | Impact of the Regulation Strategy on the Transient Behavior of a Brayton Heat Pump |
| title_short | Impact of the Regulation Strategy on the Transient Behavior of a Brayton Heat Pump |
| title_sort | impact of the regulation strategy on the transient behavior of a brayton heat pump |
| topic | high-temperature heat pump Brayton heat pump dynamic modeling transient simulation control system |
| url | https://www.mdpi.com/1996-1073/17/5/1020 |
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