Siemens has developed a technology to use waste heat, which previously had gone unused, to generate electricity.
The solution employs silicone oils, which have a lower enthalpy of vaporization than water, and is needed because waste heat produced in industrial plants or power stations often does not have enough energy to drive a turbine with steam. Siemens recently introduced its "Organic Rankine Cycle" module.
Under this solution, the working medium drives a turbine, and then cools and reverts to its initial liquid state. Thus, electricity can be generated without the additional use of energy or raw materials, and without producing additional carbon dioxide emissions.
Conventional power plants usually convert only about 50 percent of fuel energy into electricity, and most of the waste heat is released through a cooling tower. A great deal of waste heat is produced in other industries as well, such as chemicals, glass-making, paper-making and steel production to name just a few examples. It is used often to pre-heat other substances or, if that is not possible and if the waste heat is not hot enough to drive a conventional steam turbine, the valuable energy is wasted.
Using silicone oils, Siemens engineers have succeeded in converting this energy into electricity. These oils have a much lower enthalpy of vaporization than water, and can be used to generate electricity from waste heat of only about 300 degrees.
The Organic Rankine Cycle (ORC) module is derived from the so-called Rankine Cycle, a closed loop used in steam-driven heat engines. In this case, however, organic silicone oils are used as the work medium.
The oil absorbs the waste heat energy by way of a heat exchanger. It turns to vapor and drives a turbine before being completely liquefied again in a condenser and pumped back to the vaporizer. The heat released in the cooling process is also recovered to pre-heat the oil.
The ORC module has an output of up to two megawatts; variants with higher output ratings are expected to come on line in the medium term. The heart of this module is the proven SST-060 steam turbine, which has already been installed successfully more than 850 times. The silicone oil employed in this module is chlorine-free and non-toxic.
All in all, the investment costs and maintenance costs of an ORC module are comparatively low. And thanks to the lower temperatures and pressures and other factors, it is easier to operate than conventional steam-driven turbines. The ORC module features an automatic mode and requires no additional personnel, making it a very economical option for using energy sources more efficiently
Dr. Norbert Aschenbrenner | Siemens InnovationNews
Researchers take next step toward fusion energy
16.11.2017 | Texas A&M University
Desert solar to fuel centuries of air travel
16.11.2017 | SolarPACES
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses