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- Titel:
A preliminary study of two-phase volumetric expanders and their application in ORC systems
- Dokumenttyp:
- Konferenzbeitrag
- Autor(en):
- Sindu Daniarta; Piotr Kolasiński
- Abstract:
- Organic Rankine Cycle (ORC) is considered one of the promising solutions for generating power using organic working fluid instead of water. Practically, the efficiency of ORC depends on the applied working fluid and its thermophysical properties. Also, it is significantly influenced by the temperature and the flow rate of the heat source. Some heat sources (e.g., waste heat or heat obtained from biomass combustion) may feature floating thermal and output characteristics. The ORC system may be designed in a way enabling its operation in two-phase conditions (i.e., for the vapour quality of 0 < 𝑥 < 1) to efficiently utilize such heat sources. The applicability of turbines is in this operating condition significantly limited as they tend to operate in dry vapour conditions. The literature review shows that different volumetric machines (i.e., rotary and reciprocating positive-displacement (PD) machines, such as piston, gerotor, screw, scroll and vane) can work with liquids and wet gases. Nowadays, these machines are applied mainly as pumps and compressors, but several researchers have been investigating and modifying them into expanders that could be applied in ORC systems. The operating principle of PD pumps and compressors differ from the centrifugal one. The PD pumps are applicable to a broader range of liquids, slurries, and foams that could be pumped without product degradation. Furthermore, the PD compressors are operating at a relatively low-pressure range and are commonly used in pneumatic and refrigeration systems. The PD machines could use gases and liquids as working fluids and therefore have the potential to be modified into two-phase expanders. The application of two-phase expanders in the ORC system gives the possibility to enhance the range of operating conditions in the system. This paper presents the results of a literature review on the mathematical models and experimental results related to the application of volumetric expanders in steam and ORC power systems operating in two-phase conditions. The most important features and characteristics of the twophase expanders are discussed. Moreover, a preliminary experimental study concerning the possibility of applying a multi-vane expander for a two-phase expansion in a micro-power ORC system is reported.
- Herausgeber:
- Technical University of Munich
- Kongress- / Buchtitel:
- Proceedings of the 6th International Seminar on ORC Power Systems
- Ausrichter der Konferenz:
- Technical University of Munich
- Datum der Konferenz:
- 11.10.2021-13.10.2021
- Verlag / Institution:
- Technical University of Munich
- Jahr:
- 2021
- E-ISBN:
- 978-3-00-070686-8
- Serien-ISSN:
- 2709-7609
- Reviewed:
- ja
- Sprache:
- en
- Erscheinungsform:
- WWW
- Volltext / DOI:
- doi:10.14459/2021mp1633105
- CC-Lizenz:
- by-sa, http://creativecommons.org/licenses/by-sa/4.0
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