Design of a Phase Separation System for a Direct Steam Generation Parabolic Trough Collector Field

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Tobias Hirsch ◽  
Markus Eck
Keyword(s):  
Separation Efficiency ◽  
Large Diameter ◽  
Drainage System ◽  
Thermal Inertia ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Water Steam ◽  
Parabolic Trough Collector ◽  
Direct Steam ◽  
Central Buffer

The dynamic behavior of a parabolic trough collector field with direct steam generation under varying solar conditions is analyzed using a transient simulation model. It is found that the peak water flow rates observed during transients may reach several times the steady-state design values. Taking into account these results, a method is developed for calculating the required separation efficiency of the water-steam separator between evaporating and superheating sections of the solar field. For a field with individual phase separators arranged in each collector row, the drainage system, used for transporting the separated water from the field to a central buffer tank, is dimensionally defined. It turns out that a buffer capacity of about 0.1m3 and a large-diameter drainage line have to be foreseen in order to cope with the high liquid loads under solar transients. The results are compared to a field layout with one central separation drum in terms of materials consumption and thermal inertia. It turns out that the originally intended effect of a reduced thermal inertia is not reached when transient conditions are taken care of in the design of the components.

Field Test of Water-Steam Separators for Direct Steam Generation in Parabolic Troughs

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Markus Eck ◽  
Holger Schmidt ◽  
Martin Eickhoff ◽  
Tobias Hirsch
Keyword(s):  
Separation Efficiency ◽  
Thermal Power ◽  
Operation Mode ◽  
Test Facility ◽  
Steam Generation ◽  
Water Steam ◽  
State Tests ◽  
Start Up ◽  
Direct Steam ◽  
Solar Thermal Power Generation

Direct steam generation (DSG) represents a promising option to improve today’s parabolic trough technology for solar thermal power generation. The European DISS and INDITEP projects have proven the feasibility of the DSG process under real solar conditions at the DISS test facility at the Plataforma Solar de Almería (PSA) (Zarza, E., Valenzuela, L., Léon, J., Hennecke, K., Eck, M., Weyers, H.-D., Eickhoff, M., 2004, “Direct Steam Generation in Parabolic Troughs Final Results and Conslusions of the DISS Project,” Energy, 29, pp. 635–644). These projects have also shown that the recirculation mode is the preferred operation mode for DSG collector fields. This concept requires water-steam separators at the end of the evaporation section of the collector loop. Both compact water-steam separators for every single row or huge separation drums for the whole collector field are considered. Small compact water-steam separators show a lower inertia, reducing the time for start-up. Within INDITEP and the German R&D project SOLDI compact water-steam separators have been developed, manufactured, and tested by DLR and Siemens, with its subcontractor Framatome ANP. Prototypes of a cyclone and a baffle separator have been implemented into the DISS test facility. More than 200 tests have been performed to investigate the separation efficiency, the pressure loss, and the performance under transient conditions. This paper focuses on the steady-state tests.

Direct Steam Generation in Parabolic Trough Solar Power Plants: Numerical Investigation of the Transients and the Control of a Once-Through System

1996 ◽  
Vol 118 (1) ◽  
pp. 9-14 ◽  
Author(s):  
F. Lippke
Keyword(s):  
Power Plants ◽  
Weather Conditions ◽  
Future Generation ◽  
Numerical Approach ◽  
Steam Generation ◽  
Dynamic Reaction ◽  
Parabolic Trough ◽  
Water Steam ◽  
Direct Steam ◽  
Solar Power Plants

Direct steam generation (DSG) in parabolic troughs was first studied in the early 1980s by Murphy (1982) and Pederson (1982). Intensive research on DSG then started in 1988, when Luz identified this technology as the desired system for a future generation of its power plants. These R&D activities were not terminated on Luz’s demise in 1991, but have been continued by several institutes and companies in Europe as well as in Israel (Dagan et al., 1991, Mu¨ller et al., 1992a, b, 1993, 1994). This paper concerns the dynamic reaction of the water-steam flow. In order to investigate this, a numerical simulation program was developed at the ZSW. The numerical approach, its verification, and results of an extended study concerning the reaction and the control (ability) of a once-through DSG system at different weather conditions are presented.

Experimental characterisation of a solar parabolic trough collector used in a micro-CHP (micro-cogeneration) system with direct steam generation

Energy ◽  
2015 ◽  
Vol 83 ◽  
pp. 474-485 ◽  
Author(s):  
Jean-Louis Bouvier ◽  
Ghislain Michaux ◽  
Patrick Salagnac ◽  
François Nepveu ◽  
Dominique Rochier ◽  
...  
Keyword(s):  
Steam Generation ◽  
Parabolic Trough ◽  
Parabolic Trough Collector ◽  
Direct Steam ◽  
Cogeneration System ◽  
Experimental Characterisation

Application of direct steam generation into a solar parabolic trough collector to multieffect distillation

Desalination ◽  
1999 ◽  
Vol 125 (1-3) ◽  
pp. 139-145 ◽  
Author(s):  
Lourdes García-Rodríguez ◽  
Ana I. Palmero-Marrero ◽  
Carlos Gómez-Camacho
Keyword(s):  
Steam Generation ◽  
Parabolic Trough ◽  
Parabolic Trough Collector ◽  
Direct Steam

Test Results of a Combined Storage System for Parabolic Trough Power Plants With Direct Steam Generation

2011 ◽  
Author(s):  
Doerte Laing ◽  
Martin Eickhoff ◽  
Michael Fiß ◽  
Matthias Hempel ◽  
Mirko Meyer-Gru¨nefeldt ◽  
...  
Keyword(s):  
Power Plants ◽  
Storage System ◽  
Heat Transfer Fluid ◽  
Steam Generation ◽  
Parabolic Trough ◽  
Two Phase ◽  
Water Steam ◽  
Direct Steam ◽  
Two Phase Heat Transfer ◽  
Heating Up

For future parabolic trough plants direct steam generation in the absorber pipes is a promising option for reducing the costs of solar thermal energy. 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 for the two phase fluid water/steam. Concrete storage is used for the process steps involving transfer of sensible heat — i.e. preheating of water and superheating of steam — while for the two-phase evaporation a phase change material (PCM) storage will be deployed. This technology is currently developed by DLR and Ed. Zu¨blin AG within the project ITES, funded partly by the German Ministry for the Environment, Nature Conservation and Nuclear Safety. A combined storage solution with a 22 m3 concrete storage test module for superheating of steam and a 8.5 m3 PCM-storage for evaporation of water was build in 2009 in a direct steam test loop, set up at the power plant Litoral of Endesa in Carboneras, Spain. This high temperature storage system has a total capacity of approx. 1000 kWh and it will be the first demonstration of such a combined storage system for the two phase heat transfer fluid water/steam. Commissioning was completed in 2010, implying first heating-up of the concrete storage to expel the excess water in the concrete, first heating-up of the PCM storage including final filling of the storage with salt. Cycling tests for each storage unit separately are in progress. Combined testing will start in 2011. Results on the commissioning and testing will be reported in the paper.

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