SOLAR THERMAL CONVERTER Russian patent published in 1998 - IPC

FIELD: solar energy conversion to produce heat for domestic and industrial needs; high-temperature solar thermal installations. SUBSTANCE: converter has straight-flow metal tube 1, heat-transfer medium selective optical absorbing layer 2 on external surface passed through evacuated glass envelope 3, and flexible members 5 compensating for thermal expansion of tube 1 which are placed between tube 1 and glass envelope 3. Heat-transfer medium tube 1, glass envelope 3, and flexible members 5 are degassed by heating in vacuum to prevent poor vacuum in vacuum cavity 4 when operating at high temperatures. Absorbing layer 2 is formed by developing embossed surfaces on various metals and alloys and retains its properties at high temperatures. Layer 2 formed on cooper provides for absorbing 95% of sun rays within comprehensive range of incidence angles of 0 to 60 deg. relative to normal. Self-radiation makes up 2-15 % of blackbody radiation. When used in conjunction with solar concentrators, converter enables raising temperature of heat-transfer medium to 300-400 C. It can be used for water heating, producing fresh water, steam, hot air, etc. EFFECT: improved reliability, enlarged functional capabilities of converter. 7 cl, 2 dwg