Reported from CSPPLAZA: In the solar tower CSP system, solar radiation is focused through a heliostat to a receiver, and the accumulated heat is heated by steam to drive a turbine to generate power. In the process of heat conduction, heat transfer liquid plays a crucial role. The temperature is the decisive factor for the thermoelectric conversion efficiency.
Now, the temperature of molten salt can reach about 550 ° C and the thermoelectric conversion efficiency is about 42%. But at the same time, when the operating temperature below 200°C molten salt will freeze.
Now imagine, if there is a medium that can raise the temperature to 1,000° C, the efficiency of thermoelectric conversion to about 50%, and still work well at low temperatures, will it be the next choice?
HelioHeat commercializes a new solar tower technology with ceramic particles as heat carrier and storage material which is under development by the German Aerospace Center. Such particles enable temperatures exceeding 1000 degrees Celsius. The particles are available at prices which allow a cost-effective thermal storage and thereby enable a demand oriented solar energy supply.
The project has gained EU funding for a demonstration plant based on this receiver And recently, the 2.5 MWth prototype receiver has successful pass the testing.
During the solar test operation of the so-called centrifugal receiver CentRec® for the generation and storage of solar high temperature heat, 965 degrees Celsius average particle temperature were measured at the receiver outlet. The core piece of the CentRec system is a rotating chamber with the rotation axis tilted by about 45 degrees downwards.
The ceramic particles with a diameter of about one millimeter are introduced at the top of the chamber. Centrifugal force keeps the particles at the inner wall of the rotating chamber.
The concentrated solar radiation enters the chamber through an aperture pointing towards the heliostat field. The radiation is then directly absorbed by the dark particles which are being heated up. With the help of gravity force the particles move slowly along the chamber wall through the receiver and are collected at the lower exit after being heated to the desired temperature.
The particle retention time can be easily controlled by adapting the rotation speed, allowing constant exit temperatures under all load conditions.
This new technology also reduce the cost of electricity and process heat produced by solar thermal power plants. On the one hand, the direct irradiation of the ceramic particles avoids the need for costly metallic superalloy tubes where the heat transfer fluid passes through. The direct absorption principle also allows increased receiver efficiencies at high temperatures.
On the other hand the large temperature range made possible by the use of ceramic particles opens new opportunities for the techno-economic system optimization, leading to a significant cost reduction for the heat exchangers and the storage system. Further advantages are in the use of bauxite particles which do not pose an environmental risk.
Since the particles, in contrast to the currently used molten salt, are not at risk of freezing, the otherwise necessary trace heating of tubes and components can be omitted, the involved cost and energy expenditures are saved.
Do you want to get more information about ceramic particles as heat carrier and storage material? Mr. Lars Amsbeck, Managing Director of HelioHeat will make a keynote speech under the theme of Solar tower with ceramic particles as heat carrier and storage material on 2019 China International CSP Conference & CSPPLAZA 6th Annual Conference (CPC2019).
CPC2019 is one of the largest and the most professional international annual event in global CSP industry. As the wind vane of the CSP industry, CSPPLAZA Annual Conference has now formed a wide-ranging influence in the global CSP industry. On the theme of Building the Global CSP Community, the CPC2019 will discuss about global CSP industry deeply and comprehensively.
From the conference, you can understand the dynamics of global CSP industry, get deep communication and seek more cooperation opportunities. The conference will have more than 70 sponsors covering the whole CSP industry chain, and you will find what you need here.
China International CSP Conference（CPC2019） is to be held on 10-12,July,in Suzhou, China. During the conference, global CSP professionals will conduct in-depth exchanges with each other about the development of CSP plants.
For more details of the conference, please contact: Catherine@cspplaza.com