Geometric Modularity in the Thermal Modeling of Solar Steam Turbines

Topel, Monika; Spelling, James; Jöcker, Markus; Laumert, Björn

doi:10.1016/j.egypro.2014.03.184

Cited by 4 publications

(3 citation statements)

References 11 publications

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“…In this model, the tem perature of the fluid and the metal temperature are not strongly coupled; instead, weak coupling through cosimulation was performed. This simplification was proven to be adequate in the validation process of the model [8,9] for global effects, which are the ones being studied in the scope of this paper.…”

Section: Turbine Thermal Modelmentioning

confidence: 97%

“…In general, the model is based on previous work by the authors [8,9] and was created using COMSOL coupled with matlab. The over all structure of the model consists of three coupled submodels:…”

Section: Turbine Thermal Modelmentioning

confidence: 99%

“…For this, a dynamic thermal turbine model has been developed and validated [8,9] against measured temperatures from a parabolic trough CSPP.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Operational Improvements for Startup Time Reduction in Solar Steam Turbines

Topel

Genrup

Jöcker

et al. 2015

Journal of Engineering for Gas Turbines and Power

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Solar steam turbines are subject to high thermal stresses as a result of temperature gra dients during transient operation, which occurs more frequently due to the variability of the solar resource. In order to increase the flexibility of the turbines while preserving lift ing requirements, several operational modifications for maintaining turbine temperatures during offline periods are proposed and investigated. The modifications were imple mented in a dynamic thermal turbine model and the potential improvements were quanti fied. The modifications studied included: increasing the gland steam pressure injected to the end-seals, increasing the back pressure and increasing the barring speed. These last two take advantage of the ventilation and friction work. The effects of the modifications were studied both individually as well as in different combinations. The temperatures obtained when applying the combined modifications were compared to regular turbine cool-down (CD) temperatures and showed significant improvements on the startup times of the turbine.

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Section: Turbine Thermal Modelmentioning

confidence: 97%

Section: Turbine Thermal Modelmentioning

confidence: 99%

See 1 more Smart Citation

Operational Improvements for Startup Time Reduction in Solar Steam Turbines

Topel

Genrup

Jöcker

et al. 2015

Journal of Engineering for Gas Turbines and Power

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Differential Expansion Sensitivity Studies During Steam Turbine Startup

Topel

Jöcker

Paul

et al. 2015

Journal of Engineering for Gas Turbines and Power

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In order to improve the startup flexibility of steam turbines, it becomes relevant to analyze their dynamic thermal behavior. In this work, the relative expansion between rotor and casing was studied during cold-start conditions. This is an important property to monitor during startup given that clearances between rotating and stationary components must be controlled in order to avoid rubbing. The investigation was performed using a turbine thermal simplified model from previous work by the authors. The first step during the investigation was to extend and refine the modeling tool in order to include thermomechanical properties. Then, the range of applicability of the model was validated by a twofold comparison with a higher order finite element (FE) numerical model and measured data of a cold start from an installed turbine. Finally, sensitivity studies were conducted with the aim of identifying the modeling assumptions that have the largest influence in capturing the correct thermal behavior of the turbine. It was found that the assumptions for the bearing oil and intercasing cavity temperatures have a large influence ranging between ±25% from the measured values. In addition, the sensitivity studies also involved increasing the initial temperature of the casing in order to reduce the peak of differential expansion. Improvements of up to 30% were accounted to this measure. The studies performed serve as a base toward further understanding the differential expansion during start and establishing future clearance control strategies during turbine transient operation.

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The Hybrid Pathway to Flexible Power Turbines, Part I: Novel Autoencoder Methods for the Automated Optimization of Thermal Probes and Fast Sparse Data Reconstruction, Enabling Real-Time Thermal Analysis

Baker,

Rosic

2023

Journal of Engineering for Gas Turbines and Power

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The global drive towards renewable energy is imposing challenging operating requirements on power turbines. Flexible load-leveling applications must accept more frequent and demanding start-stop cycles. Full transient analyses are too computationally expensive for real-time simulation across all operating regimes so monitoring relies on sparse physical measurements. Alone, these sparse data lack the fidelity for real-time prediction of a complex thermal field. A new hybrid methodology is proposed, coupling data across a range of fidelities to bridge the limitations in the individual analyses. Combining several fidelity methods in parallel: low-order models, corrected by real-time physical measurements, are calibrated with high-fidelity simulations. The multi-faceted hybrid approach enables the real-time speed of low-order analysis at high resolution. This paper series develops the critical enabling features of the hybrid method. Real-time cross-fidelity data transition is fundamental to the hybrid methodology. A novel neural network autoencoder method is presented, facilitating complex thermal profile reconstruction. Uncovering a compressed latent space, autoencoders leverage underlying data features for fast simulation. Coupled with a dynamic mask and top-k selection, thermal probe placement can be automatically optimized. The autoencoder method is demonstrated on a turbine casing, reconstructing over 500 hours of transient operation in real-time, whilst reducing the required number of measurements by half.

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Geometric Modularity in the Thermal Modeling of Solar Steam Turbines

Cited by 4 publications

References 11 publications

Operational Improvements for Startup Time Reduction in Solar Steam Turbines

Operational Improvements for Startup Time Reduction in Solar Steam Turbines

Differential Expansion Sensitivity Studies During Steam Turbine Startup

The Hybrid Pathway to Flexible Power Turbines, Part I: Novel Autoencoder Methods for the Automated Optimization of Thermal Probes and Fast Sparse Data Reconstruction, Enabling Real-Time Thermal Analysis

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