JP2012002494A - Solar heat type air heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar heat type air heating device which can surely heat air by utilizing a beam down-type solar light collector.SOLUTION: As a heat exchange member 9 receives the solar light L reflected downward by the beam down-type solar light collector, the heat exchange member 9 can be surely heated. Further, as the air a is allowed to pass through the heated heat exchange member 9, the air a is surely heated, and heat can be conveyed to a place needing heat as the heating air b. Further, as a top face of a housing 8 is constituted of a transparent window 13, attachment of dust to the heat exchange member 9 can be prevented.

Description

  The present invention relates to a solar thermal air heater.

  A number of primary mirrors, called heliostats, reflect sunlight toward a secondary mirror supported on the top of a high tower, reflecting further downward from the secondary mirror, and directing sunlight to a point on the ground A collecting beam-down solar concentrator is known (for example, see Patent Document 1).

  In the case of this type of beam-down structure, it is known that the light receiving plate can be heated to a high temperature of 1000 ° C. or more by applying sunlight reflected downward to the light receiving plate.

JP-A-11-119105

  In this way, by directly heating the light receiving plate with sunlight, the light receiving plate becomes very hot. Therefore, it is very useful if the heat can be taken out by heat exchange. However, since the light receiving plate is too hot, the light receiving plate cannot be brought into direct contact with the heat exchange fluid (water, oil, etc.), and a useful heat exchange structure has not been proposed so far. . In particular, there has been a demand for a solar air heating apparatus that can use air that does not burn or rapidly expand even when heated by solar heat as a heat medium.

  The present invention has been made by paying attention to such a conventional technique, and provides a solar thermal air heating apparatus capable of reliably heating air using a beam down solar concentrator. is there.

  According to the first aspect of the present invention, a heat-resistant heat exchange member having a plurality of upper and lower through-holes is provided inside the housing so as to block the cross section of the housing, and a beam-down solar concentrating device is provided on the upper surface of the heat exchange member The heat exchange member is heated by applying the downward sunlight reflected in step 1, and air is heated through the upper and lower through holes of the heated heat exchange member.

  According to the second aspect of the present invention, the upper surface of the housing is formed by a transparent window having heat resistance, and sunlight is applied to the heat exchange member through the transparent window, and an air intake portion is formed in the upper space of the heat exchange member. In addition, an air discharge portion is provided in the lower space of the heat exchange member, and an air suction portion is provided on the air discharge portion side.

  According to a third aspect of the present invention, an open portion is formed on the upper surface of the housing, and sunlight is applied to the heat exchange member through the open portion, and an air intake portion is formed in an upper space of the heat exchange member, thereby exchanging heat. An air discharge portion is provided in the lower space of the member, and an air suction portion is provided on the air discharge portion side.

  According to a fourth aspect of the present invention, the upper surface of the housing is formed by a transparent window having heat resistance, sunlight is applied to the heat exchange member through the transparent window, and an air intake portion is formed in the upper space of the heat exchange member. In addition, an air discharge part is provided in the lower space of the heat exchange member, and an air delivery part is provided on the air intake part side.

  The invention according to claim 5 is characterized in that the air discharge part is installed in a state where the air discharge part is penetrated into the heat storage device in which the heat storage material is incorporated, and the air is discharged from the air discharge part that has passed through the heat storage apparatus.

  According to the first aspect of the invention, since the sunlight reflected downward by the beam-down solar condensing device is received by the heat exchange member, the heat exchange member can be reliably heated. And since air is allowed to pass through the heated heat exchange member, the air is reliably heated, and heat can be transported where necessary as heated air.

  According to invention of Claim 2, since the upper surface of a housing is formed with a transparent window, it can prevent that dust etc. adhere to a heat exchange member.

  According to the third aspect of the present invention, since the upper surface of the housing is used as an open portion and air is taken in therefrom, a large amount of air can be taken in.

  According to the fourth aspect of the present invention, since air is introduced from the upper space of the heat exchange member by the air delivery part and passes through the heat exchange member, the air passing through the delivery part is before heating, and the delivery part is There is no need for a heat-resistant structure.

  According to the invention described in claim 5, since air is discharged through the heat storage device, if the heat storage material in the heat storage device is heated, sunlight may be temporarily blocked by clouds or the like. The air can be heated and discharged by the heat stored in the hot heat material.

1 is a schematic cross-sectional view showing a beam down solar concentrator according to a first embodiment of the present invention. The schematic plan view which shows a beam down type | formula solar condensing device. Sectional drawing which shows the internal structure of a solar-heat type air heating apparatus. The top view which shows a cylindrical collector mirror. The top view which shows a heat exchange member. The perspective view which shows a heat exchange member. Sectional drawing which shows the internal structure of the solar-heat type air heating apparatus which concerns on 2nd Embodiment. Sectional drawing which shows the internal structure of the solar-heat type air heating apparatus which concerns on 3rd Embodiment. Sectional drawing which shows the internal structure of the solar-heat type air heating apparatus which concerns on 4th Embodiment.

(First embodiment)
1-6 is a figure which shows 1st Embodiment of this invention. First, a beam-down solar concentrator for obtaining solar heat will be described. In this embodiment, a case of an area in the middle latitude of the northern hemisphere such as Japan will be described as an example.

  A center mirror 1 is supported by three towers (not shown) at the center of the beam-down solar concentrator. The center mirror 1 has a partial spheroid shape in which the opposite side to the direction in which the sun exists during the day is cut out. As shown in FIG. 1, the center mirror 1 has a curved surface whose section matches an ellipse, and a first focal point A and a second focal point B exist as confocal points below.

  As shown in FIG. 2, the center mirror 1 is in a state of projecting by a predetermined angle range to the east side and the west side from the semicircle in a plan view. A plurality of heliostats 2 are radially arranged around the center mirror 1 on the north side and the east and west sides of the center mirror 1.

  The heliostat 2 has a structure that changes its direction in conjunction with the movement of the sun by a sensor (not shown), and is always controlled to reflect the sunlight L toward the first focus A. The sunlight L that has passed through the first focal point A is reflected by the center mirror 1 and collected at the second focal point B.

  A cylindrical condenser mirror 3 is installed at the second focal point B. The cylindrical condenser mirror 3 has a generally tapered cylindrical shape in which the lower opening is narrower than the upper opening, and the inner surface is a mirror surface constituted by a plurality of multi-mirror segments. All the reflected light of the heliostat 2 is reflected by the center mirror 1 and then introduced into the cylindrical condenser mirror 3. An air heating device 4 is provided on the lower side of the cylindrical condenser 3, and the air a can be changed to heated air b of about 1000 ° C.

  Next, the production of heated air will be described with reference to FIGS.

  The cylindrical condenser mirror 3 is covered with a rectangular housing 5, and a hollow portion 6 exists between the cylindrical condenser mirror 3 and the housing 5. An air inlet 7 to the hollow portion 6 is formed in the upper portion of the housing 5.

  The air heating device 4 on the lower side of the cylindrical condenser 3 has a funnel-shaped housing 8 with a thin lower portion, and a large number of heat exchange members 9 are provided so as to block the cross section of the housing 8. That is, the housing 8 is partitioned into an upper space 10 and a lower space 11 by a plurality of heat exchange members 9. The upper space 10 and the hollow portion 6 of the cylindrical condenser mirror 3 are connected via an air passage 12.

  Accordingly, the heat exchanging member 9 is arranged so as to cross the cross section of the flow path of the heat medium into which the reflected light of the heliostat 2 is introduced and which is defined by the ventilation path 12, the housing 8, the air discharge portion 15, and the like. Although air as a heat medium passes through the upper space 10 through which the reflected light passes, since the air does not scatter sunlight, the optical path of sunlight and the flow path of airflow can coexist.

  A transparent window 13 is formed on the upper surface of the housing 8 facing the lower opening of the cylindrical collector mirror 3. The transparent window 13 is formed of glass such as quartz glass having heat resistance.

  The heat exchange member 9 is black and has a multiple through-hole structure made of a silicon carbide film (SiC) and has heat resistance of 1000 ° C. or higher. The main axis of the through hole faces in the vertical direction, substantially coincides with the principal axis of the reflected light to be introduced, and substantially coincides with the principal axis of the air flow channel. Therefore, the absorption efficiency of reflected light is high, and the efficiency of heat exchange with passing air is also high.

  The heat exchange member 9 is housed in a funnel-shaped cover 14 (FIG. 6) for uniformizing the passing air. By arranging a plurality of the heat exchange members 9 together with the cover 14, the upper space 10 and the lower space 11 of the air heating unit 4 are partitioned. Further, the cover 14 has an action of guiding and adjusting the flow of the passing air, thereby reducing the air resistance. The material of the heat exchange member 9 is not limited to silicon carbide as long as it has good heat absorption and has the above heat resistance.

  The lower part of the housing 8 is an air discharge part 15, which is provided with a suction part 16 that generates a pressure gradient along a flow path such as a fan and sucks air on the upstream side to flow downstream. Yes. The pressure on the downstream side of the suction unit 16 is higher than that on the upstream side, and air is discharged to the downstream side (low pressure side such as atmospheric pressure).

  Next, the process for producing the heated air b will be described.

  All the sunlight L reflected by the center mirror 1 is introduced into the cylindrical collector mirror 3 and reflected and collected by the inner surface thereof, but the cylindrical collector mirror 3 itself is also heated during reflection. The cylindrical condenser mirror 3 itself becomes very hot. Therefore, the air a taken in from the air intake 7 is preliminarily heated in contact with the back surface of the cylindrical condenser mirror 3 in the hollow portion 6.

  The air a heated to some extent is introduced into the upper space 10 of the air heating unit 4 through the air passage 12. The air a introduced into the upper space 10 passes through the heat exchange member 9 and reaches the lower space 11.

  At this time, the heat exchanging member 9 is irradiated with the high energy sunlight condensed from the lower opening of the cylindrical condenser mirror 3 through the transparent window 13, and the heat exchanging member 9 emits solar heat with extremely high efficiency. Since it absorbs and becomes very high temperature, when the air a passes the heat exchange member 9 arrange | positioned in the flow path, it becomes the heating air b. The heated air b can be drawn by the suction unit 16 and sent to a necessary place.

  According to this embodiment, since the sunlight L reflected downward by the beam-down solar concentrator is received by the heat exchange member 9, the heat exchange member 9 can be reliably heated.

  And since the air a is allowed to pass through the heated heat exchange member 9, the air a is surely heated, and the portion where heat is required as the heated air b can be conveyed. Therefore, since the heat exchange member 9 performs heat exchange with the heat medium simultaneously with absorption of sunlight L, the energy efficiency is high.

  Further, since the upper surface of the housing 8 is closed by the transparent window 13, a sand boundary of the heat exchange member 9 does not adhere, and maintenance is easy.

(Second Embodiment)
FIG. 7 is a diagram showing a second embodiment of the present invention. This embodiment includes the same components as those in the first embodiment. Therefore, the same constituent elements are denoted by common reference numerals, and redundant description is omitted.

  In this embodiment, the transparent window on the upper surface of the housing 17 is omitted to form the open portion 18. By setting it as the open part 18, a large amount of air a can be introduced from the surroundings and allowed to pass through the heat exchange member 9, which is suitable when a large volume of heated air b is required even if the temperature is somewhat low. .

(Third embodiment)
FIG. 8 is a diagram showing a third embodiment of the present invention. This embodiment also includes the same constituent elements as those of the first embodiment, and the same constituent elements are denoted by the same reference numerals and redundant description is omitted.

  In this embodiment, the air intake 19 is formed directly in the upper space 10 of the housing 21 of the heat exchange member 9 without using the housing 20 of the cylindrical condenser mirror 3. The air intake 19 is provided with an air a delivery section 22.

  According to this embodiment, air a is sent from the delivery unit 22 into the upper space 10, and the air a can be heated and taken out from the air discharge unit 23 while passing through the heat exchange member 9.

  Since the air a passing through the delivery part 22 is not yet heated, the temperature is low, and it is not necessary to make the delivery part 22 heat resistant, and the structure of the delivery part 22 can be simplified.

(Fourth embodiment)
FIG. 9 is a diagram showing a fourth embodiment of the present invention. This embodiment is also provided with the same component as 1st Embodiment, and while attaching | subjecting a common code | symbol about the same component, the overlapping description is abbreviate | omitted.

  In this embodiment, the extension portion 24 is formed in a portion of the air discharge portion 15 ahead of the suction portion 16. The extension part 24 penetrates the heat storage device 25 in a meandering state. A heat storage material 26 made of a molten salt (a mixture of potassium nitrate and sodium nitrate) is built in the heat storage device 25, and the extension 24 penetrates through the heat storage material 26.

  The heat storage material 26 is heated by the high-temperature air b that passes through the extension 24 at normal times, and can store the heat therein. The molten salt that is the heat storage material 26 is solid at room temperature but melts when heated, so that the contact area with the surface of the extension 24 is increased, and highly efficient heat exchange can be performed.

  Since the energy of sunlight L is large in the daytime when the sun is close to the south-central position, the heat storage material 26 can be heated and stored in the interior by the air b sufficiently heated by the energy. Therefore, even if the sun is blocked by clouds and the heat exchange member 9 that originally heats the air a is temporarily not exposed to sunlight L, the air a guided from the air discharge unit 15 is When passing through the heat storage material 26 via the extension 24, the heat storage material 26 is heated by heat exchange. Therefore, while passing through the extension 24, the air a is discharged as heated air b.

  Since such a heat storage device 25 is provided, even if the situation where the sunlight L is temporarily blocked occurs, the heated air b can always be discharged continuously.

  In each of the above embodiments, the heat exchange members 9 are arranged in a horizontal state. However, the heat exchange members 9 may be arranged in a curved shape with a lower center. The center mirror 1 of the beam-down solar concentrator is not limited to an elliptical shape, and may have other shapes.

7, 19 Air intake part 8, 17, 21 Housing 9 Heat exchange member 10 Upper space 11 Lower space 13 Transparent window 15, 23 Air discharge part 16 Suction part 22 Sending part 24 Extension part 25 Heat storage device 26 Heat storage material L Sunlight

A cylindrical condenser mirror 3 is installed at the second focal point B. The cylindrical condenser mirror 3 has a generally tapered cylindrical shape in which the lower opening is narrower than the upper opening, and the inner surface is a mirror surface constituted by a plurality of multi-mirror segments. All the reflected light of the heliostat 2 is reflected by the center mirror 1 and then introduced into the cylindrical condenser mirror 3. An air heating unit 4 is provided on the lower side of the cylindrical condenser mirror 3, and the air a can be changed to heated air b of about 1000 ° C.

The air heating unit 4 on the lower side of the cylindrical condenser 3 has a funnel-shaped housing 8 with a thin lower portion , and a large number of heat exchange members 9 are provided so as to block the cross section of the housing 8. That is, the housing 8 is partitioned into an upper space 10 and a lower space 11 by a plurality of heat exchange members 9. The upper space 10 and the hollow portion 6 of the cylindrical condenser mirror 3 are connected via an air passage 12.

Further, since the upper surface of the housing 8 is closed by a transparent window 13, such as sand dust of the heat exchange member 9 is not adhered, maintenance is easy.

Since the energy of sunlight L is large in the daytime when the sun is close to the south-central position, the heat storage material 26 can be heated and stored in the interior by the air b sufficiently heated by the energy. Therefore, if the sun is blocked by the clouds, even state sunlight L does not hit the originally heat exchanging member 9 for heating the air a is generated temporarily, the air a guided from the air discharge unit 15, When passing through the heat storage material 26 via the extension 24, the heat storage material 26 is heated by heat exchange. Therefore, while passing through the extension 24, the air a is discharged as heated air b.

Claims (5)

A heat-resistant heat exchange member having a plurality of upper and lower through holes in a state where the cross section of the housing is closed inside the housing,
Heating the heat exchange member by applying downward sunlight reflected by a beam-down solar concentrator on the upper surface of the heat exchange member, and heating the air through the upper and lower through holes of the heated heat exchange member A solar-heated air heating device.   The upper surface of the housing is formed by a heat-resistant transparent window, and sunlight is applied to the heat exchange member through the transparent window, and an air intake portion is formed in the upper space of the heat exchange member, and the lower space of the heat exchange member The solar heat type air heating device according to claim 1, wherein an air discharge portion is provided on the air discharge portion, and an air suction portion is provided on the air discharge portion side.   An open part is formed on the upper surface of the housing, sunlight is applied to the heat exchange member through the open part, an air intake part is formed in the upper space of the heat exchange member, and an air discharge part is formed in the lower space of the heat exchange member The solar heat type air heating device according to claim 1, wherein an air suction part is provided on the air discharge part side.   The upper surface of the housing is formed by a heat-resistant transparent window, and sunlight is applied to the heat exchange member through the transparent window, and an air intake portion is formed in the upper space of the heat exchange member, and the lower space of the heat exchange member The solar heat type air heating device according to claim 1, wherein an air discharge portion is provided on the air intake portion, and an air delivery portion is provided on the air intake portion side.   5. The air discharge unit is installed in a state where the air discharge unit penetrates the heat storage device in which the heat storage material is incorporated, and the air that has passed through the heat storage device is discharged from the air discharge unit. The solar-heated air heating apparatus as described in.

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