Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Molten Salts for Efficient Solar Thermal Plants

07.03.2011
Researchers from Siemens intend to substantially boost the efficiency of solar thermal power plants and thus reduce the costs of this climate-neutral method of power generation.

They intend to use mixtures of molten salts as heat transfer media in the High Performance Solar Thermal Power project. In conjunction with partners, scientists from Siemens will construct a pilot plant in Portugal and test the use of molten salt mixtures in parabolic trough power plants.

This type of power plant uses concave parabolic mirrors that focus sunlight on an absorber tube at the mirrors’ focus. A heat transfer medium flows along the tube. The heat is transferred to a conventional water-steam cycle in a downstream steam generator, where it is converted into electricity by a steam turbine and a generator. The main factor determining the efficiency of the power generation process is the maximum working temperature of the heat transfer medium. As this temperature increases, the utilization of the steam turbine approaches its optimum value.

Siemens intends to use molten salts instead of thermal oil, thereby increasing the working temperature from 400 to more than 500 degrees Celsius. Eliminating the use of thermal oil would also prove beneficial as it has a relatively high vapor pressure and is highly flammable. Salts suitable for use as heat transfer media consist of, for example, a mixture of sodium and potassium nitrates. These are non-flammable and have almost zero vapor pressure. As a result, the plant can be operated without pressure—and that means more safely. Furthermore, salts have a higher heat storage capacity than thermal oil and are considerably cheaper. The solidification temperature of the salt previously used for this purpose must, however, be reduced from the current temperature of approximately 220 degrees to less than 150 degrees Celsius so that it doesn’t “freeze” overnight. Optimizing the composition of the salt mixture and thus its physical properties is an important goal being pursued by scientists from Siemens Corporate Technology and from Siemens Energy.

The pilot plant will be constructed on the grounds of the University of Evora, Portugal. The solar components, the steam generator system, the pipework system, and the pumps will be adapted to cope with the higher temperatures and the properties of the molten salt mixture. The researchers will use the results gained to plan, and implement verification procedures at, commercial facilities with installed powers in excess of 50 megawatts. The project is being funded by Germany’s Federal Ministry for the Environment. The participants include the German Aerospace Center (DLR) and other companies.

Dr. Norbert Aschenbrenner | Siemens InnovationNews
Further information:
http://www.siemens.com

More articles from Power and Electrical Engineering:

nachricht Producing electricity during flight
20.09.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Solar-to-fuel system recycles CO2 to make ethanol and ethylene
19.09.2017 | DOE/Lawrence Berkeley National Laboratory

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>