Bubelis, Evaldas

Norrman, Sixten

Szogradi, Marton

Teräsvirta, Antti

Ylätalo, Jaakko

English

KITopen

RESEARCH POSTER PRESENTATION DESIGN © 2015www.PosterPresentations.coma Fortum Power and Heat Oy, 02150 Espoo, Finlandb VTT, PO Box 1000 02044 Espoo, Finlandc Karlsruhe Institute of Technology (KIT), Institute for Neutron Physics and Reactor Technology Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, GermanyThe Demonstration Fusion Power Plant (DEMO) project aims to construct and successfully operate an industrial size fusion power plant. In order to succeed in this task, several challenges in the current fusion technologies have to be overcome. One key challenge is related to the pulsed operation of the Tokamak-fusion reactor. It is estimated that the tokamak reactor can run only in pulsed mode introducing challenges to conventional power conversion systems, which are commonly designed for continuous operation. The DEMO power conversion system has to be designed to manage a periodical drop in fusion heat production during the dwell period. The DEMO-project work packages Plant Level System Engineering (PMI) and Balance of Plant (BOP) aim to design a thermal- and cost-effective Primary Heat Transfer System (PHTS) and Power Conversion System (PCS) for the DEMO fusion reactor. INTRODUCTIONMETHODRESULTS AND CONCLUSION• The solid energy storage system succeeded in keeping turbine power around 50% during the dwell period without reducing steam quality or lowering steam temperature excessively (Figure 8, 10, 11) • However the loading time of the thermal storages and refilling of the steam drum delay the reaching of full operation mode to 30 minutes → only 1.5 hours of full power mode during 2 hour pulse (Figure 8)• Also, the size of the equipment was deemed to be too large as it has to be to located inside the tokamak containment building (radioactive helium contamination)• Steam drum and steam generator equipment are subject to high pressures during turbine ramp down (Figure 9)• The thermal storage and steam drum concept is not a feasible solution for future development of the DEMO conceptREFERENCES[1] Apros® version 6.07.33, Espoo: http://www.apros.fi, 2018[2] S. Kiviluoto, S.Norrman, P.Urhonen, S.Ciattaglia, Integrated System Level Simulation and Analysis of DEMO with Apros, Proceedings of Nuclear Science and Technology Symposium (NST2016) CONTACTDr Jaakko Ylätalo, jaakko.ylatalo@fortum.com, mobile +358 40 7694708• Personnel at KIT and Kraftanlagen Heidelberg performed a steady-state balance analysis of two thermal storage concepts with either external or integrated thermal storage system. • The integral system was deemed more suitable. Evaluated sizing the thermal mass is ~2000 m3 and the required size of the steam drum was around 230 m3.• The concept was used to dimension and construct a dynamic 1-D Apros model for a solid energy storage concept analyzed by VTT and Fortum. [1,2]• In the solid energy storage concept, thermal accumulators and a steam drum are used to store heat during operation and are unloaded during the dwell period.Jaakko Ylätaloa, Antti Teräsvirtaa, Sixten Norrmanb, Marton Szogradib and Evaldas BubeliscDynamic Modelling of a Solid Energy Storage Concept for pulsed operation DEMO fusion power plant (Direct Cycle) Figure 1: Pulse and dwell period thermal power in a single inboard and outboard breeding blanket section, combined pulse thermal power of tokamak 2101.7 MWFigure 2: Evaluation of required thermal output rates of the thermal storages by Kraftanlagen HeidelbergFigure 5: Distributed thermal storage solution envisioned for the steam generatorsFigure 6: Steam drum arrangement used to store saturated steam  during turbine ramp down Figure 7: Final full PCS layout in the Apros model with integrated thermal storage and steam drum. All the thermal capacity is divided between economizer, boiler and superheaterCondenserTurbogeneratorDeaeratorFeed Water Preheating SectionEconomizerTorus (IB/OB) Thermal Accumulator IIHeat Flow - FusionSH SteamHe Hot Side (500 °C)He Cold Side (290 °C) Feed WaterExpanded SteamSteam AccumulatorFeed Water PumpSteam Generator Thermal Accumulator ISuperheaterHeat Flow – External -He Compr.Saturated Steam102030405060708090100Turbine Load [%]10 20 30 40 50 60 70 80 90 100 110 120 130 140Time [min]Fusion Power Output [%]Ramp Rate: 5 %/minMax. Capacity50 % Min. Load150 160 170 180Ramp Rate: 5 %/min1st Pulse: Turbine Warm Start and Thermal and Steam Accumulator Full loading Ramp Rate: 5 %/min2nd Pulse: Thermal and Steam Accumulator Reloading1st Dwell: Unloading of Steam Accumulator via External Heat FlowUnloading of Thermal AccumulatorsExcess SH Steam condensated inside Steam AccumulatorFigure 3: Integral thermal storage concept with PCSFigure 4: Turbine ramping scheme designed for the pulse-dwell operation with storage system Figure 8 Figure 9Figure 10 Figure 11

Dynamik Modelling of a Solid Energy Storage Concept for pulsed operation DEMO fusion power plant (Direct Cycle)

  Dynamic Modelling of a Solid Energy Storage Concept for pulsed operation DEMO fusion power plant (Direct Cycle)    Jaakko Ylätaloa*, Antti Teräsvirtaa, Sixten Norrmanb, Marton Szogradib and Evaldas Bubelisc   aFortum Power and Heat Oy, 02150 Espoo, Finland bVTT, PO Box 1000 02044 Espoo, Finland cKarlsruhe Institute of Technology (KIT), Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany *Corresponding author: jaakko.ylatalo@fortum.com  The Demonstration Fusion Power Plant (DEMO) project aims to construct and successfully operate an industrial size fusion power plant. In order to succeed in this task, several challenges in the current fusion technologies have to be overcome. One key challenge is related to the pulsed operation of the Tokamak-fusion reactor. It is estimated that the tokamak reactor can run only in pulsed mode introducing challenges to conventional power conversion systems, which are commonly designed for continuous operation. The DEMO power conversion system has to be designed to manage a periodical drop in fusion heat production during the dwell period. The DEMO-project work packages Plant Level System Engineering (PMI) and Balance of Plant (BOP) aim to design a thermal- and cost-effective Primary Heat Transfer System (PHTS) and Power Conversion System (PCS) for the DEMO fusion reactor. As part of these work packages, modelling studies were done by KIT, VTT and Fortum during 2018. Personnel in KIT performed a steady-state balance analysis of several PCS concepts directly thermally connected to the Helium Cooled Pebble Bed PHTS (Direct Cycle) both during normal pulse (power) operation and during 10 minutes dwell time operation with the Ebsilon simulation tool. Ebsilon results were used to dimension and construct a dynamic 1-D Apros model for a solid energy storage concept analyzed by VTT and Fortum. In the solid energy storage concept, thermal accumulators and a steam drum are used to store heat during operation and are unloaded during the dwell period. The solid energy storage system succeeded in keeping turbine power around 50% during the dwell period; however the Apros model also showed strong transients in process parameters, which could be problematic when considering plant safety and process component wear. Keywords: DEMO fusion power plant, Apros, dynamic modelling, tokamak, small energy storage Topic Category  Models and Experiments for FNT Presentation Preference □ Oral Presentation X Poster Presentation  

https://publikationen.bibliothek.kit.edu/1000096025/32724839

Dynamik Modelling of a Solid Energy Storage Concept for pulsed operation DEMO fusion power plant (Direct Cycle)

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