Big Solar Furnace with 1000 kW furnace capacity. Advances in solar energy conversion based on achievements in creating and maintaining efficient solar power plants, the coefficient of efficiency of which depends on the nature of their intended implication. The first in high-performance solar energy conversion (on Earth's orbit density of radiant energy from the Sun is 1340 W/m2) is performed at a concentration of solar radiation flux up to 1000 W/cm2. In solar engineering concentration of solar radiation is effected by means of mirror concentrating systems (MCS) on the basis of a paraboloid of rotation. Mirror-concentrating systems are optical-mechanical systems, including a heliostat field concentrator (single [complete unit] or composite, depending on the size of the midsection), receiver (technology tower), system of measurement, monitor and control. MCS can effectively use solar power for high-temperature research, testing and technological processes, power generation, hydrogen production, as well as other operations that require high power and high radiant flux density
As is known, concentrators represent the only tool allowing to concentrate solar energy into focus with capacity to get the temperature up to 3,000 oC, what in turn creates the conditions for synthesis, purification and high-temperature materials processing. Low power concentrators starting from 5 kW are large objects in terms of optics. To solve some special problems the need arises to build large-dimensional solar concentrators with area of over 1000m2. Throughout the world, there are currently about a dozen of such experimental solar concentrators with power from 5 kW to several MW. The largest of the existing at present concentrators with a thermal output of 1000 kW are solar furnaces at Odeillo (in the Pyrénées-Orientales in France) and Parkent (Uzbekistan) - Big Solar Furnace (BSP).
BSP allows creation in a focal zone of the steady-state radiation flux up to 1000 W/cm2 with the help of mirror concentrating systems of concentrators with midsection of the reflecting surface of 1840 m2 and 62 heliostats with a total reflective surface of 3022.5 m2 in a continuous tracking of the Sun with an accuracy of 3 angle/min. In contrast to the French Furnace, on the basis of Large Solar Furnace (Uzbekistan, Parkent) a special production line for processing of synthetic materials in it for use in ceramic production and an automated process control system is provided. A technology for the synthesis of ceramic materials with preset and predetermined properties using the method of radiating heating in the Big Solar Furnace. The study of processes of interaction of a concentrated light beam with a substance discovered the mechanism of formation of nano-dispersed particles in the field of concentrated light radiation, what has become the basis for creating the technology of nanopowders on the Big Solar Furnace. The development of this area could lead to new methods in helio-materials technology, whose goal is the creation of new oxide and composite materials with a set in advance complex of physical and chemical properties using concentrated solar energy. As the esteemed President Islam Abduganievich Karimov stated, - the foreign scientists recognized helio-materials technology to be the one of priority trends of science in Uzbekistan, and Uzbekistan now has the priorities recognized by the international community in the field of radiation and helio-materials technology / Islam Abduganievich Karimov "Uzbekistan on the threshold of the 21st century: threats to security, conditions of stability and progress". Publishers "O’zbekiston" - 1997. Tashkent. Analysis of methods to produce materials at temperatures up to 3,000 ° C in the traditional sources of heating (electron-beam exposure, arc heating, plasma heating, laser heating, high-frequency heating) shows that such methods are energy intensive and energy-consuming and require special process conditions, have no ability to monitor and control the thermodynamic equilibrium, stoichiometry of oxygen; contaminate the melt by electrode material, and do not provide the specified purity oxide materials with a high degree of homogeneity and compliance with stoichiometry.
Unique properties of solar heating provide the following:
•synthesizing from a melt high purity oxide materials, what is very important for optical glasses, glass ceramics and special materials;
• hardening of materials by radiation modification of the surface;
• conversion of concentrated solar energy into electrical and thermal energy;
• synthesis of hydrogen;
• conversion of concentrated solar energy in infrared and laser irradiation;
• high-speed input of concentrated solar energy for synthesis of composite materials consisting of low and high temperature components. In this case, the low-temperature components have no time to evaporate and react in the melt with high-temperature components. This allows synthesizing a new class of complex compounds;
•conducting skull melt at high temperatures (3,0000C) and preserving the purity of the initial furnace-charge and carrying out selective treatment (purification) of the melt due to the evaporation of volatile and low-temperature components;
• quenching of the melt with cooling rates up to 106 deg/s for materials in amorphous and metastable states, as well as recording high-temperature phases;
At present, based on the experience in BSP creating and operating
integrated studies and comprehensive analysis of solar technology are carried out in the following areas:
-development of optical elements of large solar power stations;
-development of technology for converting concentrated solar energy into electrical and thermal energy, as well as for hydrogen production;
-development of technology for converting concentrated solar energy into infrared and laser irradiation;
- design management of high-temperature solar energy power stations, installation, adjustment, and their introduction into operation;
-development of new calculating methods for mirror concentrating systems (MCS) -
-development of methods for control and monitoring the alignment of reflecting surfaces of MCS and measurement of the concentration field;
-development of new methods for automatically programmed heliostat tracking system;
-improvement of parameters of a unique bench-testing unit designed on the basis of the complex "Sun."
On this basis, the following results were obtained:
•multifunctional ceramics (high-temperature heaters, thermocouple converters, gas-fired burners);
• structural ceramics (printed circuit plates, tubes, terminal points (nozzles), cutting tools);
• refractory ceramics (ceramic components for engines, hardsurfacing overlay coatings);
• optical, superconducting, and other types of ceramic materials for various industries
• nanopowders for modern industries.
Within the framework of the Program for human resources capacity building in the field of using solar, wind, bio-, and hydro-energy based on BSP in 2000 was established. Now the Training Centre successfully operates with involvement of young professionals, students, Master-degree and PhD students from higher educational establishments of the Republic, as well as from neighboring countries.
BSP plays an important role as a unique research tool for solving fundamental and applied problems in science and technology.