SOLAR-HEAT COLLECTOR Russian patent published in 2001 - IPC

FIELD: solar-energy engineering, applicable in devices converting the electromagnetic energy of the Sun to the heat energy for heating of heat-transfer agent. SUBSTANCE: optimized shape of light transmitting section 1 of solar-heat collector cowling 5 is attained proceeding from the condition of ensuring of a constant angle of incidence of sun rays passing through the center of the maximum chord of the generator of cowling light-transmitting section 1 onto the surface of cowling 5 in the morning and evening hours, to this end, extreme right-hand and left-hand sections 2 and 3 of the generator of light-transmitting section 1 of the solar-heat collector cowling 5 have a shape corresponding to the following dependences: , where ρ - radius vector in polar coordinates, whose pole coincides with the middle of the maximum chord section of the generator of light-transmitting section 1 of cylinder cowling 5, m; ϕ -vectorial angle, rad; γ -angle between the direction of the Sun from the pole and the tangent to the Sun from the pole and the tangent to the generator in the point of intersection of the direction to the Sun with it, rad; A-half of the dimension of the generator maximum chord of light-transmitting section 1 of cylindrical cowling 5, m; the shape of central section 4 of the generator for π-γ≥ϕ≥γ--straight tangent to curves according to dependence (2) and dependence (3). Reduction of heat loss by heat conduction through the material of light transmitting cowling 5 is attained by the fact that the whole cowling 5 of the solar-heat collector in the form of a straight cylinder is made of two layers of thin-walled transparent plastic interconnected by longitudinal thin-walled ribs of the same material withy formation of isolated parallel hollow ducts. The hollow ducts are oriented relative to the axes of cylindrical cowling 5 in such a way that in the working position of the solar heat collector their direction would be perpendicular to the direction of the gravitational force, which ensures the most effective suppression of convective heat flows in the ducts. The heat conduction of a two-walled structure with hollow ducts makes up 2 to 3 W/m2K, which is lower than the heat conduction of a solid wall. EFFECT: optimized shape of the light-transmitting section of the collector cowling. 5 cl, 3 dwg