Considering Uncertainties in Research by Probabilistic Modeling

2012 ◽  
Author(s):  
Markus Eck ◽  
David Kretschmann ◽  
Jan Fabian Feldhoff ◽  
Michael Wittmann
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Thermal Power Plants ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Levelized Cost Of Electricity ◽  
Solar Thermal Power ◽  
Economical Evaluation ◽  
Direct Steam ◽  
Stochastic Input

Technical and economical evaluation of solar thermal power plants constantly gains more importance for industry and research. The reliability of the results highly depends on the assumptions made for the applied parameters. Reducing a power plant system to one single, deterministic number for evaluation, like the levelized cost of electricity (LCOE), might end in misleading results. Probabilistic approaches can help to better evaluate systems [1] and scenarios [2]. While industry looks for safety in investment and profitability, research is predominantly interested in the evaluation of concepts and the identification of promising new approaches. Especially for research, dealing with higher and hardly quantifiable uncertainties, it is desirable to get a detailed view of the system and its main influences. However, to get there, also a good knowledge on the stochastic interrelations and its interpretation is required. Therefore, this paper mainly assesses the influences of basic stochastic assumptions and suggests a methodology to consider suitable stochastic input, especially for parameters of systems still under research. As examples, the comparison between a parabolic trough plant with synthetic oil and direct steam generation is used.

Detailed Modeling of Parabolic Trough Collectors for the Part Load Simulation of Solar Thermal Power Plants

2012 ◽  
Author(s):  
F. Zaversky ◽  
S. Bergmann ◽  
W. Sanz
Keyword(s):  
Heat Transfer ◽  
Power Plant ◽  
Power Plants ◽  
Thermal Power ◽  
Solar Thermal ◽  
Thermal Power Plants ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Solar Thermal Power ◽  
Direct Steam

Solar thermal power plants are a promising way of providing clean renewable electric energy. These plants concentrate the incoming solar direct irradiation in order to heat up a heat transfer fluid. The collected thermal energy can be stored or instantly delivered to a power block where part of the thermal energy is converted to electrical energy in a turbine with the connected generator. The parabolic trough collector plant is the today’s most developed solar thermal power plant type. There the solar irradiation is focused on receiver tubes which are concentrically placed to the focal lines of the parabolic trough collectors. A high temperature oil is pumped through these receiver tubes, which collects the heat and delivers it later on to the steam generator of the connected Rankine steam cycle. In order to improve the efficiency of these solar thermal power plants, the direct steam generation (DSG) within the parabolic trough collector receiver tubes is being investigated. Both types of parabolic trough collectors, the conventional type using oil as heat transfer fluid and the direct steam generation type, are subject of this paper. A detailed steady-state parabolic trough collector model was developed for each type, using the thermodynamic simulation software IPSEpro. The developed models consider the cosine-loss attenuation factor, the shading attenuation factor, optical losses, as well as thermal losses. Appropriate heat transfer and pressure loss correlations were implemented for both collector types. For the direct steam generation model, distinct collectors for the preheating section, the evaporation section and the superheating section were used. Furthermore, the suitable length of discretization for the modeling of one collector loop within a center-fed solar field was investigated. Calculated solar field performance data for the oil concept were compared to validated data available in open literature. Finally, a power plant simulation with each collector type, over the course of one reference day, showed the great potential of the direct steam generation, as well as the suitability of IPSEpro for running solar thermal power plant yield simulations.

The DISS Project: Direct Steam Generation in Parabolic Trough Systems. Operation and Maintenance Experience and Update on Project Status

2002 ◽  
Vol 124 (2) ◽  
pp. 126-133 ◽  
Author(s):  
Eduardo Zarza ◽  
Loreto Valenzuela ◽  
Javier Leo´n ◽  
H.-Dieter Weyers ◽  
Martin Eickhoff ◽  
...  
Keyword(s):  
Power Plants ◽  
New Technology ◽  
Thermal Power ◽  
Test Facility ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Solar Thermal Power ◽  
Operation And Maintenance ◽  
Direct Steam ◽  
New Generation

The DISS (DIrect Solar Steam) project is a complete R+TD program aimed at developing a new generation of solar thermal power plants with direct steam generation (DSG) in the absorber tubes of parabolic trough collectors. During the first phase of the project (1996-1998), a life-size test facility was implemented at the Plataforma Solar de Almerı´a (PSA) to investigate the basic DSG processes under real solar conditions and evaluate the unanswered technical questions concerning this new technology. This paper updates DISS project status and explains O&M-related experience (e.g., main problems faced and solutions applied) with the PSA DISS test facility since January 1999.

Development of a Thermal Energy Storage System for Parabolic Trough Power Plants With Direct Steam Generation

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Doerte Laing ◽  
Thomas Bauer ◽  
Dorothea Lehmann ◽  
Carsten Bahl
Keyword(s):  
Heat Transfer ◽  
Power Plants ◽  
Storage System ◽  
Thermal Power ◽  
Sensible Heat ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Two Phase ◽  
Solar Thermal Power ◽  
Direct Steam

For future parabolic trough plants direct steam generation in the absorber pipes is a promising option for reducing the costs of solar thermal power generation. These new solar thermal power plants require innovative storage concepts, where the two-phase heat transfer fluid poses a major challenge. A three-part storage system is proposed where a phase change material (PCM) storage will be deployed for the two-phase evaporation, while concrete storage will be used for storing sensible heat, i.e., for preheating of water and superheating of steam. A pinch analysis helps to recognize interface constraints imposed by the solar field and the power block and describes a way to dimension the latent and sensible components. Laboratory test results of a PCM test module with ∼140 kgNaNO3, applying the sandwich concept for enhancement of heat transfer, are presented, proving the expected capacity and power density. The concrete storage material for sensible heat was improved to allow the operation up to 500°C for direct steam generation. A storage system with a total storage capacity of ∼1 MWh is described, combining a PCM module and a concrete module, which will be tested in 2009 under real steam conditions around 100 bars.

The DISS Project: Direct Steam Generation in Parabolic Troughs — Operation and Maintenance Experience — Update on Project Status

2001 ◽  
Author(s):  
Eduardo Zarza ◽  
Loreto Valenzuela ◽  
Javier León ◽  
H.-Dieter Weyers ◽  
Martin Eickhoff ◽  
...  
Keyword(s):  
Power Plants ◽  
New Technology ◽  
Thermal Power ◽  
Test Facility ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Solar Thermal Power ◽  
Operation And Maintenance ◽  
Direct Steam ◽  
New Generation

Abstract The DISS (DIrect Solar Steam) project is a complete R+TD program aimed at developing a new generation of solar thermal power plants with direct steam generation (DSG) in the absorber tubes of parabolic trough collectors. During the first phase of the project (1996–1998), a life-size test facility was implemented at the Plataforma Solar de Almería (PSA) to investigate under real solar conditions the basic DSG processes and evaluate the open technical questions concerning this new technology. This paper updates DISS project status and explains O&M-related experience (e.g. main problems faced and solutions applied) with the PSA DISS test facility since January 1999.

Development of a Thermal Energy Storage System for Parabolic Trough Power Plants With Direct Steam Generation

2009 ◽  
Author(s):  
Doerte Laing ◽  
Thomas Bauer ◽  
Dorothea Lehmann ◽  
Carsten Bahl
Keyword(s):  
Heat Transfer ◽  
Power Plants ◽  
Storage System ◽  
Thermal Power ◽  
Sensible Heat ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Two Phase ◽  
Solar Thermal Power ◽  
Direct Steam

For future parabolic trough plants direct steam generation in the absorber pipes is a promising option for reducing the costs of solar thermal power generation. These new solar thermal power plants require innovative storage concepts, where the two phase heat transfer fluid poses a major challenge. A three-part storage system is proposed where a phase change material (PCM) storage will be deployed for the two-phase evaporation, while concrete storage will be used for storing sensible heat, i.e. for preheating of water and superheating of steam. A pinch analysis helps to recognize interface constraints imposed by the solar field and the power block and describes a way to dimension the latent and sensible components. Laboratory test results of a PCM test module with approx. 140 kg NaNO3, applying the sandwich concept for enhancement of heat transfer, are presented, proving the expected capacity and power density. The concrete storage material for sensible heat was improved to allow the operation up to 500 °C for direct steam generation. A storage system with a total storage capacity of approx. 1 MWh is described, combining a PCM module and a concrete module, which will be tested in 2009 under real steam conditions around 100 bar.

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