DEVICE FOR HEATING SHELTERED GROUND Russian patent published in 1994 - IPC

FIELD: farming. SUBSTANCE: device has flat thin-walled casing 1 with channel 2 for heat-transfer medium. Casing 1 is made up of two parts 3 and 4. Upper part 3, directed to flow A of radiant energy, is made transparent, lower part 4 facing ground Б is nontransparent. Joint 5 between parts 3 and 4 of casing 1 is sealed. Material of nontransparent part 4 is light-absorbing. Heat conductivity of nontransparent part 4 of casing 1 exceeds that of transparent part 3 of casing 1. Flow A of radiant solar energy comes to surface 6 of nontransparent part 4 of casing 1 and, while passing through it, is absorbed by material of nontransparent material of part 4 of casing 1. Two heat flows R₁ and R₂ originate in material of nontransparent part 4 of casing 1, contributing to rise of temperature of heat-transfer medium in channel 2 and to increase of temperature of ground Б. Heat flow R₂ gives rise to heat flow R₃ passing through transparent part 3 of casing 1. Heat flows R₂ and R₃ are controlled by conducting new portions of heat-transfer medium into channel 2 to prevent sudden drop of temperature difference between ground and working volume of protected ground with resultant favorable development of plants in hothouse in sunny weather. EFFECT: enhanced reliability of operation. 3 cl, 1 dwg