JP5611791B2 - Solar collector - Google Patents

Description

  The present invention relates to a solar heat collecting apparatus, and more particularly, an inner tube that receives sunlight collected by a light collecting mechanism and transmits energy to a heat medium that circulates inside, and an outer space of the outer periphery of the inner tube. It is related with the solar heat collecting device provided with the heat collecting tube which consists of an outer tube which forms and covers.

  Conventionally, sunlight is concentrated toward a heat collection tube by a trough-type reflector having a parabolic cross section as a condensing mechanism, and the energy is transmitted to a heat medium that circulates inside the heat collection tube A heat collecting apparatus has been proposed (see, for example, Patent Document 1), and an inner tube that receives condensed sunlight and transmits energy to a heat medium that circulates inside the heat collecting tube. And an outer tube that covers the outer periphery of the inner tube by forming a heat insulating space has been proposed (see, for example, Patent Documents 2 and 3).

  Thus, conventionally, various proposals have been made on the solar heat collecting apparatus in order to increase the light collection efficiency of the solar light and the heat collecting tube itself. In particular, Patent Document 3 discloses a heat collecting tube. About, consisting of a metal inner tube that transmits energy to a heat medium that circulates inside, and an outer tube made of glass that covers the outer periphery of the inner tube to form a heat insulating space, at both ends of the inner tube, The both ends of the outer tube are fixed via an expansion difference absorbing mechanism that absorbs the difference in thermal expansion (linear expansion) between the inner tube and the outer tube with the connecting portion of the inner tube protruding. Is disclosed.

International Publication No. 96/29745 JP 2004-239603 A JP 2004-251612 A

  However, in a conventional solar heat collecting apparatus, for a method of absorbing the thermal expansion (linear expansion) of the inner pipe in the case of connecting adjacent heat collecting pipes, for example, a special technique is used to the extent that a flexible pipe is used. No special consideration was given.

  Also, since the inner tube becomes hot due to light collection, the temperature of the end of the outer tube that is fixed to the inner tube is kept at room temperature as much as possible to reduce the conduction heat transfer to the glass outer tube. In addition, it is necessary to cool the end of the outer tube by natural convection of the surrounding air.

  In view of the actual situation of the conventional solar heat collecting apparatus, the present invention can support the heat collecting tube while absorbing the thermal expansion (linear expansion) of the inner tube when the adjacent heat collecting tubes are connected to each other. The first object is to provide a solar heat collecting apparatus.

  In addition, a second object of the present invention is to provide a solar heat collecting apparatus that can reduce conduction heat transfer to a glass outer tube.

  In order to achieve the first object, a solar heat collecting apparatus according to the present invention receives a sunlight collected by a light collecting mechanism and transmits energy to a heat medium that circulates inside the metal inner pipe. And an outer tube made of glass that covers the outer periphery of the inner tube so as to form a heat insulating space, with both end portions of the inner tube protruding from both end portions of the inner tube. In the solar heat collecting apparatus provided with the heat collecting tube fixed to each other, the adjacent heat collecting tubes are not connected to each other by a connecting member in which a screw is formed at a connecting portion of the inner tube of the heat collecting tube and a screw is formed at both ends. It connects by connecting in an expanded and contracted state, and the support shaft protruding in the horizontal direction from the surface of the inner tube in the vicinity of the connected portion can be slid into the horizontal long hole formed in the heat collecting tube support member. It is characterized by being inserted.

Furthermore, in order to achieve the second object, the solar heat collecting apparatus of the present invention has a bottomed groove-like structure in which the heat collecting tube support member has an upward opening with a space that allows ventilation, and is formed in the inner tube. sunlight irradiated from condensing mechanism to the end of the outer tube so as to fix, characterized by being adapted to cut off at the bottom of said population heat tube support member.

  In this case, the condensing mechanism comprises a trough-type reflecting mirror having a parabolic cross section, the heat collecting tube support member is fixed to the reflecting mirror, and the reflecting mirror and the heat collecting tube have a common swing axis. It can be provided on the base so as to be swingable.

  According to the solar heat collecting apparatus of the present invention, the sunlight collected by the light collecting mechanism is received, and the metal inner pipe that transmits energy to the heat medium that circulates inside the outer circumference of the inner pipe is provided. A heat collecting tube comprising an outer tube made of glass that covers and forms a heat insulating space, with both end portions of the outer tube being fixed to both end portions of the inner tube with the connecting portion of the inner tube protruding. In a solar heat collecting apparatus equipped with the above, adjacent heat collecting tubes are connected to each other by connecting them in a non-expandable state by connecting members formed with screws at both ends of the inner tubes of the heat collecting tubes. In addition, the support shaft that protrudes in the horizontal direction from the surface of the inner tube in the vicinity of the connected portion is slidably inserted into a horizontal long hole formed in the heat collecting tube support member. By connecting the heat collecting tubes adjacent to each other, the inner tubes of the heat collecting tubes are not connected by the connecting member. By screw connection to the reduced state, the coupling easily and firmly, in the vicinity of locations linked by heat collection tube support member, while absorbing thermal expansion of the inner tube (linear expansion), can be supported.

  Further, the heat collecting tube support member has a groove-like structure that blocks sunlight from the light collecting mechanism at the end of the outer tube that is fixed to the inner tube and has a space that allows ventilation. The conduction heat transfer to the glass outer tube can be reduced.

  The condensing mechanism comprises a trough-type reflecting mirror having a parabolic cross section. The heat collecting tube support member is fixed to the reflecting mirror, and the reflecting mirror and the heat collecting tube are connected to each other via a common swing shaft. By providing the base in a swingable manner, the reflecting mirror and the heat collecting tube can be configured as an integrally structured swinging body.

One Example of the solar heat collecting apparatus of this invention is shown, (a) is a front view, (b) is a side view. It is explanatory drawing which shows the connection and support structure of the heat collecting tube of the solar heat collecting apparatus. It is explanatory drawing of the heat collecting tube of the solar heat collecting apparatus, (a) is front sectional drawing, (b) is XX end elevation of (a), (c) is YY and Z- of (a). FIG.

  Hereinafter, embodiments of the solar heat collecting apparatus of the present invention will be described with reference to the drawings.

1 to 3 show an embodiment of a solar heat collecting apparatus.
This solar heat collecting apparatus is made of a metal that receives sunlight collected by a trough reflector 1 having a parabolic cross section as a light collecting mechanism, and transmits energy to a heat medium that circulates inside. It consists of an inner tube 21 and an outer tube 22 made of glass that covers the outer periphery of the inner tube 21 by forming a heat insulating space, with the connecting portions 21a of the inner tube 21 protruding at both ends of the inner tube 21. The heat collecting tube 2 is configured to be fixed at both ends of the outer tube 22.

In this case, the reflecting mirror 1 and the heat collecting tube 2 are connected to the base 4 so that the central axis L1 of the reflecting mirror 1 and the heat collecting tube 2 is along the north-south axis, It is installed so as to be swingable through the moving shaft 5.
And the solar tracking mechanism 6 which rotates the rocking | fluctuation axis | shaft 5 according to the movement of the sun is provided so that the extension direction of the surface including the bisector L2 of the reflecting mirror 1 and the heat collecting tube 2 is always directed to the sun direction. Like that.

  As a result, the sunlight Sb is always incident on the reflecting mirror 1 in parallel with the plane including the bisector L2 of the reflecting mirror 1, and the reflected light is reflected by the heat collecting tube 2 installed at the focal point of the reflecting mirror 1. The light is focused on the central axis L1.

  In this embodiment, the reflecting mirror 1 is a frame made of an aluminum extrusion-molded material in which an aluminum plate serving as a support material and a high-reflectance aluminum plate serving as a mirror are overlapped. Although it is configured to be fitted into a member, a glass mirror made of a thin plate that can be bent can also be used.

  In the present embodiment, the trough-type reflecting mirror 1 having a parabolic cross section is used as the condensing mechanism, but in addition to the Fresnel mirror-type reflecting mirror composed of a plurality of long planar split mirrors, A known light collecting mechanism such as a linear Fresnel lens can be used.

  Further, as shown in FIG. 3, the heat collecting tube 2 receives the sunlight collected by the reflecting mirror 1 as a light collecting mechanism, and transmits the energy to the heat medium flowing through the inner tube 21, What consists of the outer pipe | tube 22 which forms the heat insulation space and covers the outer periphery of the inner pipe | tube 21 is used.

More specifically, a chromium oxide plating layer 21b is applied to the surface of the inner tube 21 as a solar heat absorption film.
The chromium oxide plating layer 21b as the solar heat absorption film can be formed at a relatively low cost by performing a chromium oxide plating process on the surface of the inner pipe 21 made of a pickled steel pipe.
In addition, the material and formation method of the solar heat absorption film 11a are not limited to this, As a material, in addition to chromium oxide, a nickel-based material or the like is used. In order to enhance the absorption of solar heat by physical vapor deposition (PVD), coating, etc., conventionally known ones can be employed such as coloring the surface black or applying an appropriate selective absorption film.

  The inner tube 21 may be a metal tube such as a stainless steel tube outside the steel tube, and the outer tube 22 may be a borosilicate glass tube such as a Kovar glass tube.

  Further, the heat insulating space is normally insulated by making a vacuum between the inner tube 21 and the outer tube 22.

  In addition, the heat medium that circulates in the inner pipe 21 is a heat medium such as water, heat medium oil, or molten salt that is heated to a temperature of several hundred degrees C., for example, about 400 degrees C. Can be used.

  An expansion difference absorption mechanism that absorbs the difference in thermal expansion (linear expansion) between the inner tube 21 and the outer tube 22, each of which is composed of a metal ring 25 a and a bellows 25 b joined to both ends of the outer tube 22. 25 to be fixed.

Then, the adjacent heat collecting tubes 2 configured as described above are connected to each other in a non-expandable state by connecting members 23 formed with screws at the connecting portions 21a of the inner tubes 21 of these heat collecting tubes 2 and formed with screws at both ends. In addition, the support shaft 24 protruding in the horizontal direction from the surface of the inner tube 21 in the vicinity of the connected portion is formed in the heat collecting tube support members 3a1 to 3a4 and 3b1 to 3b3 in the horizontal direction long holes 31. It is slidably inserted into.
In this case, by continuously forming a notch portion 32 that opens upward at one end side or in the vicinity of one end side of the long hole 31, the insertion of the support shaft 24 into the long hole 31 is made via the notch portion 32. Can be done smoothly.

  As a result, the adjacent heat collecting tubes 2 are connected to each other easily and firmly by screw-connecting the inner tubes 21 of the heat collecting tubes 2 to each other in a non-expandable state by the connecting member 23, and the vicinity of the connected portions is collected. The heat pipe support members 3a1 to 3a4 and 3b1 to 3b3 can support the inner pipe 21 while absorbing the thermal expansion (linear expansion).

  The end portion of the heat collecting tube 2 connected in this way that is not connected to the heat collecting tube 2 is configured as a free end. For example, by connecting the flexible tube 26 to the inner tube 21 of the heat collecting tube 2, the inner tube 21. The thermal expansion (linear expansion) of can be absorbed.

  In the present embodiment, the heat collecting tube support members 3a1 to 3a4 and 3b1 to 3b3 are fixed to the trough type reflecting mirror 1 having a parabolic cross section as the light collecting mechanism, and the reflecting mirror 1 and the heat collecting tube 2 are fixed. The reflecting mirror 1 and the heat collecting tube 2 are configured as an integral oscillating body by providing the base 4 via the common oscillating shaft 5 so as to be able to oscillate.

The heat collecting tube support members 3a1 to 3a4 and 3b1 to 3b3 are fixed to the inner tube 21 in addition to the function of supporting the heat collecting tube 2, specifically, absorbing the thermal expansion (linear expansion) of the inner tube 21. The end portion of the outer tube 22, specifically, the expansion difference absorption mechanism 25 composed of a metal ring 25 a and a bellows 25 b joined to the end portion of the outer tube 22 is irradiated from the reflecting mirror 1 as a condensing mechanism. In addition to blocking sunlight, a groove-like structure having an upward opening is provided with a ventable space for enabling heat dissipation by outside air convection.
Thereby, the conduction heat transfer to the outer tube 22 through the expansion difference absorption mechanism 25 including the metal ring 25a and the bellows 25b joined to the end of the outer tube 22 can be reduced.

  As mentioned above, although the solar heat collecting apparatus of this invention was demonstrated based on the Example, this invention is not limited to the structure described in the said Example, The structure suitably in the range which does not deviate from the meaning. Can be changed.

The solar heat collecting apparatus of the present invention has a characteristic capable of supporting the heat collecting tube while absorbing the thermal expansion (linear expansion) of the inner tube when connecting the adjacent heat collecting tubes. In particular, it can be suitably used for a solar heat collecting apparatus in which the heat medium flowing through the heat collecting tube becomes high temperature and the thermal expansion (linear expansion) of the inner tube of the heat collecting tube increases.
Moreover, since the conduction heat transfer to the glass outer tube can be reduced, it can be suitably used for a solar heat collecting apparatus and a solar heat collecting apparatus provided with a condensing mechanism.

1 Reflector (Condensing mechanism)
2 Heat collection tube 21 Inner tube 21a Connection portion 22 Outer tube 23 Connection member 24 Support shaft 25 Expansion difference absorbing mechanism 25a Metal ring 25b Bellows 3a1 to 3a4, 3b1 to 3b3 Heat collection tube support member 31 Long hole 32 Notch Sb Sunlight

Claims (3)

  A metal inner tube that receives sunlight collected by the light collecting mechanism and transmits energy to a heat medium that circulates inside, and a glass outer tube that covers the outer periphery of the inner tube by forming a heat insulating space In a solar heat collecting apparatus having a heat collecting tube in which both end portions of the outer tube are fixed to both end portions of the inner tube in a state where the connecting portion of the inner tube is protruded. The heat collecting tubes are connected to each other by forming a screw at the connecting portion of the inner tube of the heat collecting tube and connecting them in a non-expandable state by connecting members formed with screws at both ends, and an inner tube in the vicinity of the connected portion. A solar heat collecting apparatus, wherein a spindle projecting in a horizontal direction from the surface of the solar battery is slidably fitted into a horizontal long hole formed in a heat collecting tube support member. The heat collection tube support member has a bottomed groove-like structure with an openable space, and sunlight irradiated from the condensing mechanism to the end of the outer tube fixed to the inner tube , solar collector device according to claim 1, characterized in that so as to cut off at the bottom of said population heat tube support member.   The condensing mechanism comprises a trough-type reflecting mirror having a parabolic cross section, the heat collecting tube support member is fixed to the reflecting mirror, and the reflecting mirror and the heat collecting tube are connected to a base via a common swing shaft. The solar heat collecting apparatus according to claim 1, wherein the solar heat collecting apparatus is provided so as to be swingable.

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