16:00
Session 3C: Experimental prototypes (2)
Chair: Jürgen Karl
16:00
20 mins
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Design and First Operation of an Advanced ORC-CHP Architecture
Sebastian Eyerer, Fabian Dawo, Maximilian Altnöder, Roland Windhager, Anne Niederdränk, Helge Esch, Stefan Ausfelder, Robin Konrad, Michael Höger, Christoph Wieland, Hartmut Spliethoff
Abstract: Over the last years, the optimization of the Organic Rankine Cycle technology has been enforced. There are several approaches to increase the efficiency of ORC plants, including the ORC plant design, the working fluid selection, the part-load optimization together with combined heat and power (CHP) generation, as well as the optimization of the plant components. In order to contribute to these optimization measures, the design and first operation of an advanced ORC-CHP plant architecture optimized for geothermal applications, is presented in this study. This architecture extends the state of the art ORC by a two-stage expander with turbine bleeding and a regenerative direct contact preheater. The aim of this architecture is to increase the utilization of the heat source, the flexibility and the part-load efficiency of the plant. In order to evaluate the performance of this ORC-CHP concept, a test rig has been constructed. The test rig is heated with a 200 kW electrical resistance heater, which is controlled by pulse width modulation. As expander, a twin screw compressor is used, which operates in reverse mode and R1233zd(E) is applied as working fluid. Besides an in-depth description of the test rig, the system is analyzed in its complete operational range. Therefore, experiments are conducted with varying heat loads of the district heating network. With this, an operation strategy of the ORC system for the full operational range is derived.
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16:20
20 mins
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Velocity Field Measurement of Supersonic Free Jet Expansion of R245fa Gas at Organic Rankine Cycle Operating Condition
Omid Nematollahi, Hadi Samsam-Khayani, Mahdi Nili-Ahmadabadi, Sang Youl Yoon, Kyung Chun Kim
Abstract: Turbomachinery is designed and evaluated based on Computational Fluid Dynamics (CFD) simulations, which use the ideal gas law to model the fluid thermodynamic properties. This assumes that the deviation between a real gas and an ideal gas is very small. When turbomachinery operates in regions where this assumption does not hold, real gas effects should be considered. This deviation from an ideal gas particularly occurs in Organic Rankine Cycle (ORC) expanders, where the Mach number in the expander nozzles goes up to 1 which makes the flow supercritical. Up to date, CFD simulations have been validated in a case with ideal gas law which is not reliable. R245fa is classified as a frequent ORC working fluid which act as a dense gas in high-pressure regions which real-gas effects are dominant. Therefore, having a real experimental benchmark for validation of CFD models are crucial. To the best of author’s knowledge, there is no published document related to the R245fa flow structures in supersonic or even subsonic conditions. To extend a benchmark for the future CFD simulation a supersonic free jet of R245fa in the supersonic region is presented. To visualize the flow structures of jet an ORC is modified with replacing the expander with a Laval nozzle. Particle Image Velocimetry (PIV) has been used to quantitate the velocity field and study the flow structures inside the jet. The PIV system includes a PIVCAM 10-15 CCD camera, a double-pulsed Nd-Yag laser with a maximum power of 200 mJ/pulse, a TSI 610032 synchronizer, and a computer. The time difference between two consecutive images for capturing a suitable flow image near the model changes from 1 μs while the frequency of laser pulse was 3 Hz indicating the time difference between each double pulses. In this study, the working fluid fogs have been used tracking particles. The results showed that a Mach number of 1.6 has been reached using the current design of the nozzle.
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16:40
20 mins
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A Comprehensive Geothermal System in the Usage of Oilfield Associated Water from Abandoned Oil Wells
kang Chen, Yang Du, Yi Yang, Yiping Dai, Jiangfeng Wang, Pan Zhao
Abstract: High water-cut oil wells are weak in exploitation of crude oil but cost a lot for maintenance, an appropriate way to deal with this problem is making full use of the waste heat from the oilfield associated water. A comprehensive geothermal system was proposed to the cascade utilization of the geothermal water from the oil well, and it consisted of a power generation system based on organic Rankine cycle (ORC), a gathering heat tracing system, an absorption refrigeration system for house cooling, and a house heating system. Exergy and sensitivity analysis about the ambient temperature were conducted to evaluate the thermal performance of the comprehensive system, and heat consumption equivalent was applied to assess its economic performance. Results showed that the best evaporating pressure of ORC subsystem was 650kPa, and the overall system could work with a exergy efficiency higher than 42.5% the whole year. Moreover, nearly 8916 tons of kgce could be saved every year. The work done may provide some guidance for researchers in the usage of the geothermal water based on high-cut oil wells.
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17:00
20 mins
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Geothermal Binary Demonstration Power Plant Pangolombian-Lahendong, Indonesia
Stefan Kranz, Stephanie Frick, Ali Saadat, Yanto Suyanto, Roy Bandoro
Abstract: In order to successfully demonstrate geothermal binary power plant technology at an Indonesian site and to intensify the know-how transfer in this technology field a German-Indonesian collaboration project has been initiated in 2013 involving GFZ Potsdam (Germany), the Agency for the Assessment and Application of Technology in Indonesia (BPPT) and PT Pertamina Geothermal Energy (PGE). Geothermal binary power plants are not yet an established technology at Indonesian sites. The first commercial binary units have been commissioned at Sarulla field just in 2017. Due to their adaptability binary plants could however be implemented at much more sites and help to increase the geothermal capacity in Indonesia.
The binary demonstration power plant Pangolombian-Lahendong is a prototype that has been developed in order to meet different technical, but also non-technical constraints. The power plant cycle is integrated using two intermediate closed water cycles for heat supply and heat removal which is an untypical set-up for geothermal binary power plants. Technical components from Germany but also Indonesian suppliers have been used.
The binary demonstration plant started operation in September 2017. Since then more than 1 GWh (status end of December 2018) could be produced and a full-automatic and parallel grid operation could be proven. In January 2019 the demonstration plant has been handed over to an Indonesian partner. Besides the power supply for geothermal injection pumps the binary plant shall serve for education and research.
This paper describes the technical concept and will summarize the first operational experiences.
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