EXERGY ANALYSIS OF DIRECT SUN RADIATION CONCENTRATION

Abstract

In the article substantiates that the exergy method of thermodynamic analysis, along with the entropy method, makes it possible to determine the locations of the most significant thermodynamic losses in energy conversion processes. It is shown that the use of exergy analysis makes it possible to estimate the thermodynamic losses at each stage of the energy conversion scheme and to reduce them. It is proved that exergetic analysis of the concentration of solar radiation in solar installations with paraboloid mirrors, as well as in optical systems of tower solar thermal plants with horizontal fields of flat heliostats and thermal power plants with horizontal parabolic cylindrical mirrors will allow to increase the energy of these transformations. Exergy analysis of the concentration of solar radiation was performed. For the first time, solar radiation is treated as radiant heat flux, which is characterized by its own temperature, and its exergy is determined within the canonical Carnot cycle. On the basis of the new interpretation of the temperature of the radiant flux, an analytical expression was obtained for the radiation temperature of the thermal radiation of the Sun, both for direct radiation and for diffuse. The dependence of the direct solar radiation density on the mass of the atmosphere is found. The above formulas allow to calculate the radiation temperature of solar radiation and the density of exergy flux on the Earth's surface and in the focus of the concentrator mirror.