Optimal Design of a Ljungström Turbine for ORC Power Plants: From a 2D model to a 3D CFD Validation
In the last few years, waste-energy recovery systems based on the Organic Rankine Cycle (ORC) have gained increased attention in the global energy market as a versatile and sustainable technology for thermo-electric energy conversion from low-to-medium temperature sources, up to 350 °C. For a long t...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-07-01
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| Series: | International Journal of Turbomachinery, Propulsion and Power |
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| Online Access: | https://www.mdpi.com/2504-186X/5/3/19 |
| _version_ | 1797561862244532224 |
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| author | Umberto Coronetta Enrico Sciubba |
| author_facet | Umberto Coronetta Enrico Sciubba |
| author_sort | Umberto Coronetta |
| collection | DOAJ |
| description | In the last few years, waste-energy recovery systems based on the Organic Rankine Cycle (ORC) have gained increased attention in the global energy market as a versatile and sustainable technology for thermo-electric energy conversion from low-to-medium temperature sources, up to 350 °C. For a long time, water has been the only working fluid commercially adopted in powerplants: axial and, for smaller machines, radial inflow turbines have been the preferred expanders since their gulp capacity matches the <i>ρ</i>-<i>T</i> curve of water steam. The density of most organic compounds displays extremely large variations during the expansion (and the volume flow rate correspondingly increases along the machine channels), so that Radial Outflow Turbines (ROTs) have been recently considered instead of traditional solutions. This work proposes a two-dimensional inviscid model for the stage optimization of a counter-rotating ROT, known as the Ljungström turbine. The study starts by considering five different working fluids that satisfy both the gulp requirements of the turbine and the hot source characteristics. On the basis of a limited number of geometric assumptions and for a fixed set of operating conditions, different kinematic parameters are optimized to obtain the most efficient cascade configuration. Moreover, as shown in the conclusions, the most efficient blade profile leads to higher friction losses, making further investigation regarding the best configuration necessary. |
| first_indexed | 2024-03-10T18:20:36Z |
| format | Article |
| id | doaj.art-30e4ddcb9df64c97aad8c85b85ed2cb4 |
| institution | Directory Open Access Journal |
| issn | 2504-186X |
| language | English |
| last_indexed | 2024-03-10T18:20:36Z |
| publishDate | 2020-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Turbomachinery, Propulsion and Power |
| spelling | doaj.art-30e4ddcb9df64c97aad8c85b85ed2cb42023-11-20T07:18:48ZengMDPI AGInternational Journal of Turbomachinery, Propulsion and Power2504-186X2020-07-01531910.3390/ijtpp5030019Optimal Design of a Ljungström Turbine for ORC Power Plants: From a 2D model to a 3D CFD ValidationUmberto Coronetta0Enrico Sciubba1Department of Mechanical and Aerospace Engineering, University of Roma Sapienza, Via Eudossiana 18, 00184 Roma, ItalyDepartment of Mechanical and Aerospace Engineering, University of Roma Sapienza, Via Eudossiana 18, 00184 Roma, ItalyIn the last few years, waste-energy recovery systems based on the Organic Rankine Cycle (ORC) have gained increased attention in the global energy market as a versatile and sustainable technology for thermo-electric energy conversion from low-to-medium temperature sources, up to 350 °C. For a long time, water has been the only working fluid commercially adopted in powerplants: axial and, for smaller machines, radial inflow turbines have been the preferred expanders since their gulp capacity matches the <i>ρ</i>-<i>T</i> curve of water steam. The density of most organic compounds displays extremely large variations during the expansion (and the volume flow rate correspondingly increases along the machine channels), so that Radial Outflow Turbines (ROTs) have been recently considered instead of traditional solutions. This work proposes a two-dimensional inviscid model for the stage optimization of a counter-rotating ROT, known as the Ljungström turbine. The study starts by considering five different working fluids that satisfy both the gulp requirements of the turbine and the hot source characteristics. On the basis of a limited number of geometric assumptions and for a fixed set of operating conditions, different kinematic parameters are optimized to obtain the most efficient cascade configuration. Moreover, as shown in the conclusions, the most efficient blade profile leads to higher friction losses, making further investigation regarding the best configuration necessary.https://www.mdpi.com/2504-186X/5/3/19turbine CFDLjungström turbineOrganic Rankine Cycle |
| spellingShingle | Umberto Coronetta Enrico Sciubba Optimal Design of a Ljungström Turbine for ORC Power Plants: From a 2D model to a 3D CFD Validation International Journal of Turbomachinery, Propulsion and Power turbine CFD Ljungström turbine Organic Rankine Cycle |
| title | Optimal Design of a Ljungström Turbine for ORC Power Plants: From a 2D model to a 3D CFD Validation |
| title_full | Optimal Design of a Ljungström Turbine for ORC Power Plants: From a 2D model to a 3D CFD Validation |
| title_fullStr | Optimal Design of a Ljungström Turbine for ORC Power Plants: From a 2D model to a 3D CFD Validation |
| title_full_unstemmed | Optimal Design of a Ljungström Turbine for ORC Power Plants: From a 2D model to a 3D CFD Validation |
| title_short | Optimal Design of a Ljungström Turbine for ORC Power Plants: From a 2D model to a 3D CFD Validation |
| title_sort | optimal design of a ljungstrom turbine for orc power plants from a 2d model to a 3d cfd validation |
| topic | turbine CFD Ljungström turbine Organic Rankine Cycle |
| url | https://www.mdpi.com/2504-186X/5/3/19 |
| work_keys_str_mv | AT umbertocoronetta optimaldesignofaljungstromturbinefororcpowerplantsfroma2dmodeltoa3dcfdvalidation AT enricosciubba optimaldesignofaljungstromturbinefororcpowerplantsfroma2dmodeltoa3dcfdvalidation |