THE CONCENTRATION COEFFICIENT OF SOLAR RADIATION AND METHODS OF MEASURING IT IN SOLAR POWER PLANTS WITH CONCENTRATORS
The article is devoted to the research of concentration coefficient of solar radiation and methods of measuring it in solar power plants with concentrators. The essential indicators of modules with concentrators have been given. The interconnection of the geometric shape of a solar radiation concentrator with a density of the concentrated solar radiation flow has been shown. This allows us to approach the definition of the main indicators of the solar radiation concentrators. The determination of the indicator allows to classify solar radiation concentrators. The classification is necessary for the development of new kinds of solar modules with concentrators. The scheme of solar radiation flows in the solar module with a concentrator is given. The change of density of a concentrated solar radiation flow causes the change in the current intensity in the photoelectric meter for radiation flux density (PMRD). Knowing the intensity of currents in the photoelectric meter for radiation flux density with a concentrator and without a concentrator, the value of the current concentration coefficient of solar radiation can be computed. The technical standards for the sensor of the photoelectric meter for radiation flux density is given: the resistivity is 0.1 Ohm×cm, the square of a sensor surface is 0.4x0.8 mm, the spectral response is 0.01-0.2 a/W for range of 0.5-1 µm, the range of solar radiation change is 4×10-1 - 4×103 W/cm2. The direct measurement of the solar radiation concentration coefficient in the solar power plants with concentrators has been given and the electrical circuit for reading the volt-amps diagram of the photoelectric meter for radiation flux density has been shown. The article contains the information on the work of circuit under the influence of the solar radiation on the surface of the photoelectric meter for radiation flux density. The value of the resistivity constant with current equal to 1 µA has been given and the method of measuring solar flows with the photoelectric meter for radiation flux density has been developed.