Reivindicaciones
1. Thermal solar energy collector comprising - a plurality of collecting conduits, solar energy absorbent of solar radiation (1) striking on said collecting conduits, inside of which a heat-conducting fluid circulates that collects the solar energy absorbed by the collecting conduits circulates, said collecting conduits being arranged in a vertical position, and the set of collecting conduits comprising one heat-conducting fluid inlet end and one outlet end, - means for delivering heat-conducting fluid to the collecting conduits, connected to the inlet ends of said collecting conduits, and - means for collecting the heat-conducting fluid from the collecting conduits, connected to the outlet ends of said collecting conduits, said thermal solar energy collector being characterized in that the collecting conduits, at least part of the means for delivering the heat-conducting fluid to the collecting conduits and at least part of the means for collecting the heat-conducting fluid from the collecting conduits are located in the interior of an airtight box (100), whose structure comprises - a resistant metallic internal plate (61), covered, on the face that faces to the interior of the box, with a high index reflectivity layer (8) painted or adhered thereto - a resistant metallic external plate (63), and between the internal (61) and the external (63) layers - an intermediate volume (62) filled with the thermal insulation material, the airtight box (100) comprising, apart from the side walls, - an upper wall (5), - a lower wall (6), - a rear wall (7) in which at least part of the means for delivering the heat-conducting fluid and at least part of the means for collecting the heat-conducting fluid are inset in airtight housings covered by seals made of elastic and thermal insulation materials which absorb the deformations of said means for delivering and means for collecting the heat-conducting fluid in the range of 0.1%, and - a front wall (4) with an surface opening for the passage of the solar radiation (1) to the collecting conduits, and said surface opening closed by a transparent cover (2) inset in the front wall (4) by means of a pressure seal (3). 2. Thermal solar energy collector, according to claim 1, characterized in that - the collecting conduits are a plurality of vertical channels (29) having a rectangular straight section and forming a continuous panel (28) of channels (29) with a flat front surface, - and in that the means for delivering the heat-conducting fluid are connected to the inlet ends of the channels (29), and the means for collecting the heat-conducting fluid are connected to the outlet ends of the channels (29). 3. Thermal solar energy collector, according to claim 1, characterized in that - the collecting conduits are a plurality of collecting tubes (11) which form a vertical bundle (25) - and in that the means for delivering the heat-conducting fluid are connected to the inlet ends of the collecting tubes (11), and the means for collecting the heat-conducting fluid are connected to the outlet ends of the collecting tubes (11). 4. Thermal solar energy collector, according to any of the preceding claims, characterized in that - the means for delivering the heat-conducting fluid to the collecting conduits comprises - a plurality of first connection tubes (17) comprising a 90° bend, and connected at one of their ends to the inlet ends of the collecting conduits, and at the other end to - at least one cylindrical horizontal inlet tank (15), having semispherical finishing pieces at its two longitudinal ends, inset in the rear wall (7) in an airtight housing covered by an elastic and thermal insulation first seal (16) that covers it in its whole volume, and that accommodate deformations of the inlet tank (15) of 0.1%, said inlet tank (15) being connected in an area which is diametrically opposed to that of the first connection tubes (17) to - a plurality of heat-conducting fluid inlet tubes (13) to the collector - and in that the means for collecting the heat-conducting fluid from the collecting conduits comprises - a plurality of second connection tubes (18) comprising a 90° bend, and, connected at one of their ends to the outlet ends of the collecting conduits, and at the other end to - at least one cylindrical horizontal outlet tank (19), having semispherical finishing pieces at its two longitudinal ends, inset in the rear wall (7) in an airtight housing covered by an elastic and thermal insulation second seal (20) which covers it in its whole volume, and which absorbs deformations of the outlet tank (19) of 0.1%, being said outlet tank (19) being connected in an area which is diametrically opposed to that of the second connection tubes (18) to - a plurality of heat-conducting fluid outlet tubes (21) to the collector. 5. Thermal solar energy collector, according to any of the preceding claims, characterized in that - the airtight box (100) comprises at its lower wall (6) a suction channel (9) for the connection of a suction compressor for making the vacuum in the interior of said airtight box (100), - and in that in said suction channel (9) there is a shut-off valve (10). 6. Thermal solar energy collector, according to any of the claims 2 to 4, characterized in that it additionally comprises a temperature homogenization tank (26) located between the collecting conduits, at half the height thereof, which divides said collecting conduits into two longitudinal sections by height. 7. Thermal solar energy collector, according to any of the claims 2 to 4, characterized in that - it comprises a metallic screen (27) for radiation absorption, having high conductivity, fixed to the front part of the bundle (25) of collecting tubes (11), - and in that said metallic screen (27) for radiation absorption is covered with a layer having a high absorptivity and a low emissivity to radiation, selected between paint and an adhesive. 8. Thermal solar energy collector, according to any of the preceding claims, characterized in that the external surface of the walls (4, 5, 6, 7) of the airtight box (100) is covered with a coating (8) having high reflectivity to radiation, selected between paint and an adhesive. 9. Thermal solar energy collector, according to any of the preceding claims, characterized in that the internal surface of the walls (4, 5, 6, 7) of the airtight box (100) is covered with a coating (8) having high reflectivity to radiation, selected between paint and an adhesive. 10. Thermal solar energy collector, according to any of the claims 4 to 9, characterized in that - the bundle (25) of collecting tubes (11) is divided into a plurality of sub-bundles (25'), - it comprises a supporting piece (30) arranged between two consecutive sub-bundles (25') parallel to said sub-bundles (25'), said supporting pieces (30) resting by their rear edge on the rear wall (7) of the airtight, box, and the transparent cover (2) resting on the front edge of the supporting pieces (30), - and in that the means for delivering the heat-conducting fluid to the collecting tubes (11) comprise an inlet tank (15) for each one of the sub-bundles (25'), and the means for collecting the heat-conducting fluid from the collecting tubes (11) comprise an outlet tank (19) for each one of the sub-bundles (25'). 11. Thermal solar energy collector, according to the preceding claim, characterized in that the supporting pieces (30) are transparent and made of the same material as the transparent cover (2). 12. Thermal solar energy collector, according to claim 10, characterized in that the' supporting pieces (30) are made of the same material as the internal plate (61) of the structure of the airtight box (100), and with the same high index reflectivity coating (8). 13. Thermal solar energy collector, according to any of the preceding claims, characterized in that - the outlet tubes (21) comprise a 90° outlet bend (34) for the vertical arrangement of said outlet tubes (21), - and in that the means for collecting the heat-conducting fluid from the collecting conduits additionally comprise a pressure and temperature homogenization and mixing tank (32) connected to the extreme end of the outlet tubes (21) - and in that the means for delivering the heat-conducting fluid to the collecting conduits, and the means for collecting the heat-conducting fluid from the collecting conduits, are thermally insulated. 14. Thermal solar energy collector, according to claim 2 and 3, characterized in that - the means for delivering the heat-conducting fluid to the bundle (25) of collecting tubes (11) comprise - a distribution head (41), to which the heat-conducting fluid arrives through - an inflow conduit (42) which goes through crosses the rear wall (7) of the airtight box (100) through a hole made on said rear wall (7) in which a fourth spherical seal (43) is provided - in that the means for collecting the heat-conducting fluid from the bundle (25) of the collecting tubes (11) comprise a collecting funnel (33) connected - at its larger end to the outlet end of the collecting tubes (11) - and at its smaller end to an outlet conduit (34) going through the rear wall (7) of the airtight box (100) through a hole drilled on said rear wall (7) in which a third spherical seal (35) is provided. 15. Thermal solar energy collector, according to claim 14, characterized in that the collecting tubes (11) are oblique relative to the vertical at a 10° angle. 16. Thermal solar energy collector, according to claim 14, characterized in that - the bundle (25) of collecting tubes (11) is divided into a plurality of sub-bundles (25'), - in that it comprises a supporting piece (30) arranged between two consecutive sub-bundles (25') parallel to said sub-bundles (25'), said supporting pieces (30) resting on their rear edge on the rear wall (7) of the airtight box, and the transparent cover (2) resting on the front edge of the supporting pieces (30), - in that the means for delivering the heat-conducting fluid to the collecting tubes (11) comprise for each one of the sub-bundles (25') - a distribution head (41), to which the heat-conducting fluid arrives through - an inflow conduit (42) going through the rear wall (7) of the airtight box (100) through a hole made on said rear wall (7) in which a fourth spherical seal (43) is provided, - and in that the means for collecting the heat-conducting fluid from the collecting tubes (11) comprise for each one of the sub-bundles (25') a collecting funnel (33) connected - on its larger end to the outlet end of the collecting tubes (11) - and on its smaller end to an outlet conduit (34) going through the rear wall (7) of the airtight box (100) through a hole drilled on said rear wall (7) in which a third spherical seal (35) is provided. 17. Thermal solar energy collector, according to any of the claims 10 to 12, and 16, characterized in that - the transparent cover (2) that closes the surface opening of the front wall (4) comprises a plurality of transparent blocks (46) each one arranged covering each one of the sub-bundles (25') of the collecting tubes (11), so that the glass covers of each sub-bundle are the longitudinal glass blocks, along the vertical direction of the collector, being inset in both the front and rear walls of the box, finishing at their upper and lower ends by the inset in the upper and lower walls; it being possible to use this transparent cover morphology in blocks in the case of using fluid tanks inset in the rear wall, (15) and (19), as well as conduits, (42) and (34), embedded into the spherical seals in said wall. 18. Thermal solar energy collector, according to any of the claims 1 to 4, characterized in that - the interior of the airtight box (100) is filled with an inert gas selected from nitrogen and carbon dioxide, - and in that the internal pressure of the airtight box (100) is maintained substantially equal to the atmospheric pressure by means of a pressure control circuit comprising - a gas extraction tube (49) that has - a first shut-off valve (50) - and a first gas flow control valve (51) mechanically or electromechanically activated by the pressure differences existing between the interior of the airtight box (100) and the atmospheric pressure, - a first gas reservoir (52) that stores the inert gas extracted from the airtight box (100) when it is necessary for pressure control, and that is at a lower pressure than the atmospheric pressure, it being connected to - a compressor (53) which takes the gas from the first gas reservoir (52) and injects it into - a second gas reservoir (54) which is a higher pressure than the atmospheric pressure, and that injects inert gas into the airtight box (100) when it is necessary for pressure control, through - a gas outlet tube (55) in the airtight box (100), that has - a second gas flow control valve (56) mechanically or electromechanically activated by the pressure differences existing between the interior of the airtight box (100) and the atmospheric pressure, and - a second shut-off valve (57) the first gas reservoir (52) being reinforced to withstand pressure differences equal to the atmospheric pressure, and the second gas reservoir (54) being reinforced to withstand pressures at least five times the atmospheric pressure. 19. Thermal solar energy collector, according to any of the claims 14 and 16, characterized in that - the third spherical seal (35) and the fourth spherical seal (43) arranged in the rear wall (7) of the airtight box (100) are made from a sphere made of elastic and thermal insulation materials which accommodate deformations of 0.1 % in the outlet conduit (34) and in the inflow conduit (42), - a cylindrical drilled hole being made in said sphere - whose axis coincides with a diameter of the sphere, - and whose radius is equal to the external radius of the conduit (34, 42). 20. Thermal solar energy collector, according to any of the claims 14 and 16, characterized in that - the third spherical seal (35) and the fourth spherical seal (43) arranged in the rear wall (7) of the airtight box (100) are made from - a first semispherical part (47) - and a second semispherical part (48) complementary to the first semispherical part (47) made of elastic and thermal insulation materials which accommodate deformations of 0.1% in the outlet conduit (34) and in the inflow conduit (42), - which are mounted around the conduits (34, 43) and fixed by the pressure exercised by the rear wall (7) of the airtight box (100). 21. Thermal solar energy collector, according to any of the preceding claims, characterized in that - it comprises an additional transparent cover (65) fixed in parallel to the transparent cover (2), inset in the front wall (4) of the airtight box (100) by means of an additional pressure seal (66) existing between both of them - an intermediate space (64) having a smaller thickness than the transparent covers (2, 65) connected to the exterior by means of - a plurality of holes (67) drilled at the lower part of the front wall (4) of the airtight box (100), which comprise a first filter (68) at one of the ends of each one of the holes (67) and a second filter (69) at the other end, both filters (68, 69) having a sieve with holes smaller than one millimeter. 22. Thermal solar energy collector, according to any of the preceding claims, characterized in that it comprises - a plurality of first fins, (58) obliquely welded in the interior of the front wall (4) of the airtight box (100), placed above the transparent cover (2), forming an acute angle with said front wall (4) and directed towards the lower wall (6) of said airtight box (100), - a plurality of second fins (60) obliquely welded in the interior of the front wall (4) of the airtight box (100), placed below the transparent cover (2), forming an acute angle with said front wall (4) and directed towards the lower wall (6) of said airtight box (100), - and a plurality of third fins (59) obliquely welded along the interior of the rear wall (7) of the airtight box (100), forming an acute angle with said rear wall (7) and directed towards the upper wall (6) of said airtight box (100), the fins (58, 59, 60) being made of an insulation material and covered with a high radiation reflectivity coating, selected between paint and an adhesive, and having said third fins (59) such a length that at their expansion at the collector nominal operation temperature, their free end remains separated from the rear surface of the collecting conduits by a distance that is between half a millimeter and one millimeter
