JP7019977B2 - How to design a sun-shielding device, a sun-shielding member, and a sun-shielding device - Google Patents

Description

The present invention relates to a solar radiation shielding device, a solar radiation shielding member, and a method for designing a solar radiation shielding device for blocking solar radiation.

In the field of construction, "ZEB (Net Zero Energy Building)", which makes the annual energy balance of buildings zero, is being focused on. One of the elemental technologies of this ZEB is solar shielding (for example, Non-Patent Document 1). In this non-patent document 1, solar shielding is mentioned as a design for reducing the load on the outer skin.

In addition, a solar radiation adjusting device in consideration of the shielding effect in summer and winter and the direction of daylighting has also been studied (see, for example, Patent Document 1). The solar radiation control device of this patent document has a plurality of slats, each slats having a first main surface having a flat surface and a second main surface opposite to the first main surface. , Each of the plurality of slats has a first reflective structure on the first main surface side and a second reflective structure on the second main surface side. The first reflection structure has a specular reflection characteristic of retroreflecting near infrared rays incident from the first main surface side at an incident angle in a predetermined range, and the second reflection structure has a second main surface. It has a specular reflection characteristic that specularly reflects near infrared rays incident from the surface side, and a plurality of slats are arranged in a direction in which the longitudinal direction is parallel and intersects the longitudinal direction, with the first main surface on the same side. There is.

Japanese Unexamined Patent Publication No. 2017-2708

Takeshi Ito, Hiroyuki Fukuda, Hirohide Shimaoka: Obayashi Technical Research Institute Bulletin No80 2016, "Definition of ZEB and Efforts of Obayashi", [online], [Search on May 22, 2017], Internet, <URL: https //www.obayashi.co.jp/technology/shoho/080/2016_080_14.pdf ＞

When sunlight is reflected in the sunlight shielding device, the outside air temperature rises due to the reflected light on the outer periphery of the building depending on the direction of the reflected light. Further, when sunlight is taken in the building, there is a problem that the temperature inside the building rises or becomes dazzling when the amount of light taken in is large.

-The solar shielding device for solving the above-mentioned problems is a solar shielding device in which a plurality of horizontally extending solar shielding members are tilted and arranged in the vertical direction, and the upper side surface of the solar shielding member. A diffuse reflection surface was provided on the lower surface and a sky reflection surface was provided on the upper surface of the solar radiation shielding member. As a result, the solar radiation received by the solar shading device is reflected to the sky to reduce the reflection to the surrounding buildings and the ground, so that the thermal environment around the building in which the solar shading device is provided can be improved. Further, since the transmitted light from the diffuse reflection surface enters the indoor side where a person is present, the glare due to the reflection can be reduced, and a human-friendly visual environment can be realized. Here, the sky reflecting surface means a surface that reflects the solar radiation incident on the solar shielding device in the direction of the sky within a predetermined range.

-The solar shielding member for solving the above-mentioned problems is an inclined solar shielding member, which constitutes a plurality of solar shielding devices arranged side by side in the vertical direction and extends in the horizontal direction, and is diffused on the upper side surface and the lower surface. A reflection surface was provided, and a sky reflection surface was provided on the upper surface. As a result, the sunlight received by the solar shielding member is reflected to the sky to reduce the reflection to the surrounding buildings and the ground, so that the thermal environment around the building provided with the louver can be improved. Further, since the transmitted light from the diffuse reflection surface enters the indoor side where a person is present, the glare due to the reflection can be reduced, and a human-friendly visual environment can be realized.

-In the solar radiation shielding member, it is preferable that the first member provided with the diffuse reflection surface is fitted with the second member provided with the sky reflection surface. As a result, since the two members are fitted and configured, it is possible to manufacture a solar shielding member having different reflection characteristics on the upper surface and the lower surface.

-In the above-mentioned solar shielding member, it is preferable that a connecting portion to which a connecting member to be connected to another solar shielding member is attached is provided on a part of the upper surface thereof. This makes it possible to reliably support a plurality of solar radiation shielding members.

-In the solar radiation shielding member, the sky reflecting surface is the sky reflecting ratio in the sky reflecting surface based on the solar altitude and the amount of solar radiation at the place where the solar shielding device is installed and the optical characteristics calculated by the ray tracing method. It is preferable that the shape is such that the aperture ratio of the solar radiation shielding device is increased. As a result, it is possible to form a shape that reflects a large amount of solar radiation received by the solar radiation shielding member in the sky. Here, the sky reflectance is a ratio obtained by dividing the amount of light reflected in the direction of the sky within a predetermined range by the amount of incident light (solation amount).

-As a method of designing a solar shielding device for solving the above problems, a solar shielding device in which a plurality of solar shielding members extending in the horizontal direction are tilted and arranged in the vertical direction is designed using a computer. In the design method, the solar shielding member has a diffusion reflecting surface provided on the upper side surface and the lower surface and a sky reflecting surface provided on the upper surface, and the computer has a shape of the solar shielding member. In the parametric model that determines the above, the simulation of changing the angle and length of the sky reflecting surface in the shape to calculate the sky reflecting surface ratio in the sky reflecting surface and the opening ratio of the solar shielding member is repeated, and the simulation is performed. The calculation result in which the angle and length of the sky reflecting surface used in the above and the calculated sky reflectance and the opening rate are associated with each other is stored, and based on the magnitude of the sky reflecting rate and the opening rate in the calculation result. , Determine the shape of the solar shielding member. This makes it possible to design a shape that reflects a large amount of solar radiation received by the solar radiation shielding member used in the solar radiation shielding device in the sky.

According to the present invention, it is possible to improve the thermal environment inside and outside the building and to realize a human-friendly visual environment.

The perspective view of the louver installed in Tokyo in this embodiment. FIG. 3 is a cross-sectional view of a feather plate used for the louver of FIG. Schematic configuration diagram of a shape design system for designing the shape of a feather plate in an embodiment. Flow diagram of pretreatment work for louver shape design. Sectional view of the prototype used for pretreatment of louver shape design. The flow diagram of the ray tracing simulation in an embodiment. The flow chart of the shape design process of a feather plate in an embodiment. Explanatory drawing explaining parametric model in embodiment. A table showing the Pareto solution of shape optimization in the embodiment. It is a figure explaining the reflected light locus before and after optimization in an embodiment, (a) is an incident angle before optimization 30 °, (b) is an incident angle 50 ° before optimization, (c) is before optimization. The incident angle is 70 °, (d) is the optimized incident angle of 30 °, (e) is the optimized incident angle of 50 °, and (f) is the reflected light locus when the optimized incident angle is 70 °. Is shown. It is a graph explaining the louver optical characteristics for each incident angle with respect to the direct sunlight before and after optimization, (a) shows the reflectance, and (b) shows the transmittance. The figure which shows the cross-sectional outer shape of the louver installed in each area in this embodiment.

Hereinafter, an embodiment in which the design method of the solar radiation shielding device, the solar radiation shielding member, and the solar radiation shielding device is embodied will be described with reference to FIGS. 1 to 12. The solar radiation shielding device and the solar radiation shielding member of the present embodiment have a shape corresponding to the latitude and orientation of the place where they are installed.

As shown in FIG. 1, the louver 10 (sunlight shielding device) of the present embodiment is arranged in an opening provided in the outer wall of the building frame. This louver 10 is installed in the south direction in Tokyo (region). The louver 10 includes a plurality of blade plates 20 (solar shielding members) separated from each other in the vertical direction. The wing plate 20 is a long object extending in the horizontal direction. These feather plates 20 are connected at both ends by connecting rods 15 penetrating in the vertical direction. Each feather plate 20 is inclined at the same angle so that the inside of the building is at a high position and the outside of the building is at a low position.

FIG. 2 is a cross-sectional view of the feather plate 20 used for the louver 10 of FIG. The feather plate 20 of the present embodiment includes a first member 30 that constitutes a side surface portion and a back surface portion (lower surface portion), and a second member 40 that constitutes an upper surface portion (front surface portion). In the blade plate 20 of the present embodiment, the second member 40 is internally fitted in the first member 30.

The first member 30 is made of a material having a surface (diffuse-reflecting surface) having a diffuse-reflecting property. In the present embodiment, the first member 30 diffuse reflection surface is configured by attaching a wood grain film to the surface of the A6063 material.

The second member 40 is made of a material having a surface (sky reflective surface) having sky reflective properties. The sky reflectivity means the property of reflecting the solar radiation incident on the solar radiation shielding device within a predetermined range angle (in the direction of the sky) with respect to the incident angle. In the present embodiment, sky reflectivity is generated in the range of 0 to -10 degrees with respect to the incident angle of the horizontal plane. In this embodiment, the sky reflective surface of the second member 40 is formed by electrolytic polishing the surface of the A6063 material (without buffing).

<Shape of first member 30>
Next, the details of the shape of the first member 30 will be described with reference to FIG.
The first member 30 includes a lower end side surface portion 31, a bottom portion 32, a first diffusion surface portion 33, a connecting portion 35, a second diffusion surface portion 36, an upper side surface portion 37, an upper surface portion 38, and a reinforcing portion 39. The first diffusion surface portion 33 and the second diffusion surface portion 36 have a surface on which the light reflected by the first member 30 of the feather plate 20 arranged below is incident. In the present embodiment, the inclination angles of the first diffusion surface portion 33 and the second diffusion surface portion 36 are different from each other.

The lower end side surface portion 31 extends in the vertical direction and constitutes the side surface of the lower side surface of the first member 30. The upper end side of the lower end side surface portion 31 bends toward the connecting rod 15, and constitutes a lower end engaging portion 31a that engages with the lower end side of the second member 40.

The bottom portion 32 is connected to the lower side of the lower end side surface portion 31 and extends in the horizontal direction. On the upper surface side of the portion of the bottom portion 32 to be joined to the first diffusion surface portion 33, a ridge portion 32a protruding from the upper surface is provided.
The first diffusion surface portion 33 constitutes an inclined portion that connects the end edge of the bottom portion 32 and the end edge of the connecting portion 35.

A connecting rod 15 that connects the feather plates 20 to each other is penetrated through the connecting portion 35.
The second diffusion surface portion 36 is an inclined portion that connects the end side of the connecting portion 35 and the lower end side of the upper side surface portion 37. The upper surface side of the end portion of the second diffusion surface portion 36 on the connecting portion 35 side includes a fixing portion 36a and a fitting portion 36b.

The upper side surface portion 37 extends in the vertical direction and constitutes the upper side surface portion. An opening 37a is provided in the central region of the upper side surface portion 37, and the cap 21 is inserted. The cap 21 is fixed to the reinforcing portion 39 of the first member 30 and the upper end engaging portion 47 described later of the second member 40 by a countersunk screw (not shown). The countersunk screw is inserted from the surface on the upper side surface portion 37 side toward the reinforcing portion 39. The cap 21 abuts on the reinforcing portion 39 and is fixed so as to be flush with the upper side surface portion 37.
The upper surface portion 38 is connected to the upper end portion of the upper side surface portion 37. The upper surface portion 38 has a tip portion 38a protruding from the reinforcing portion 39 connecting the upper surface portion 38 and the second diffusion surface portion 36.

<Shape of second member 40>
Next, the details of the shape of the second member 40 will be described.
The second member 40 includes a first sky reflecting portion 41, a supporting portion 43, a connecting portion 45, a connecting portion 44, a central engaging portion 46, a second sky reflecting portion 42, and an upper end engaging portion 47. In the present embodiment, the first sky reflecting unit 41 and the second sky reflecting unit 42 have a surface on which sunlight is incident. In the present embodiment, the inclination angles of the first sky reflecting unit 41 and the second sky reflecting unit 42 are different from each other.
The tip portion 41a of the first sky reflecting portion 41 engages with the lower end engaging portion 31a of the lower end side surface portion 31 of the first member 30.

The support portion 43 of the second member 40 projects downward from a part of the back surface of the first sky reflection portion 41 and has an L-shape. The tip portion of the support portion 43 engages with the ridge portion 32a of the first member 30.
The upper end of the first sky reflecting portion 41 is connected to the connecting portion 45. The connecting portion 45 is arranged above the connecting portion 35 of the first member 30, and is a portion through which the connecting rod 15 penetrates. The connecting portion 45 is connected to the second sky reflecting portion 42 via a connecting portion 44 extending in the vertical direction.

A central engaging portion 46 bent toward the second sky reflecting portion 42 is connected to the lower end portion of the connecting portion 44. The central engaging portion 46 is placed on the fixing portion 36a of the first member 30 and fitted under the fitting portion 36b.

The upper end portion of the second sky reflecting portion 42 is integrated with the upper end engaging portion 47 and fits with the upper surface portion 38 of the first member 30.
The upper end engaging portion 47 is fixed to the reinforcing portion 39 of the first member 30 when the second member 40 is fitted to the first member 30.

<Structure of shape design system>
Next, the configuration of the shape design system 50 for designing the shape of the feather plate 20 described above will be described with reference to FIG.

As shown in FIG. 3, the shape design system 50 is connected to an input unit 56, a weather information server 57, and an output unit 58.
The input unit 56 is composed of a keyboard, a pointing device, or the like, and is composed of input means for inputting various instructions and information.

The meteorological information server 57 provides data on the solar altitude and the amount of solar radiation actually measured in the past in relation to the latitude.
The output unit 58 is composed of a display or the like, and is composed of output means for outputting information processing results.

Further, the shape design system 50 includes a control unit 51 and a parametric model storage unit 53.
The parametric model storage unit 53 stores parametric model information for creating a shape by designating a variable value defined as a dimension value and a constraint condition in a three-dimensional CAD. This parametric model information includes data regarding constants or variables and calculation formulas for each horizontal length (X1 to X6) and height (Y1 to Y7) of each part of the wing plate 20. Further, corresponding to this variable, data regarding the variable range and the variable step are included.

Further, the control unit 51 includes a condition specifying unit 511, a simulation unit 512, and a shape optimization unit 513.
The condition specifying unit 511 acquires the installation conditions and the illuminance conditions of the louver 10 and calculates the period weighting coefficient. The period weighting coefficient is a value (ratio) obtained by dividing the value obtained by totaling the amount of vertical direct solar radiation for each profile angle in the period and time zone to be evaluated by the integrated value of the vertical direct solar radiation amount.

The simulation unit 512 executes the ray tracing simulation described above. For this reason, data such as a reflection model formula used for ray tracing simulation and a calculation formula used for evaluating the amount of reflected solar radiation are stored.

The shape optimization unit 513 executes the shape optimization process. In this embodiment, each variable of the parametric model is changed, and a Pareto solution satisfying "the maximum sky reflectance and the maximum aperture ratio" is calculated by using a near-culture type genetic algorithm (multi-objective optimization algorithm). .. Then, from a plurality of Pareto solutions, the solution having the highest sky reflectance is specified as the optimum solution. Here, the optimization by metaheuristics has a large number of trials, and it is inefficient if all the analysis of the evaluation period is executed. Therefore, the average optical characteristics during the evaluation period are evaluated using the period weighting coefficient described above. Specifically, the optical characteristics calculated by the ray tracing method are multiplied by a weighting coefficient and evaluated as the average optical characteristics during the evaluation period.

<Pretreatment of shape design of feather plate 20>
Next, the pretreatment of the specific shape design of the above-mentioned feather plate 20 will be described with reference to FIGS. 4 to 6.

First, as shown in FIG. 4, a prototype of the feather plate 20 is created (step S11).
Here, as shown in FIG. 5, as the prototype PT of the feather plate 20 described above, a configuration including the first member PT30 and the second member PT40 is used. The first member PT30 has a first diffusion surface portion PT33 and a second diffusion surface portion PT36 whose horizontal length and height are different from those of the first diffusion surface portion 33 and the second diffusion surface portion 36 of the first member 30 of the feather plate 20 described above. Further, the second member PT40 has a first sky reflecting portion PT41 and a second sky reflecting portion PT41 and a second sky reflecting portion 42 having different horizontal lengths and heights from the first sky reflecting portion 41 and the second sky reflecting portion 42 of the second member 40 of the feather plate 20 described above. It has a reflective portion PT42. Further, this prototype PT constitutes a sky reflecting surface by forming the surfaces of the first sky reflecting section PT41 and the second sky reflecting section PT42 in a stepped shape and reflecting the incident light twice. The first member PT30 and the second member PT40 have the same configuration as the first member 30 and the second member 40 in other parts.

Next, as shown in FIG. 4, the surface material used for the feather plate is selected (step S12). For this purpose, the reflectance of various surface materials used for the feather plate 20 is measured. A 5 cm square test piece was prepared for each of the surface materials, and measurements were taken using an ultraviolet-visible near-infrared spectrophotometer. Here, the measurement wavelength band is set to 300 to 2500 nm. After multiplying the measured spectral reflectance by the weight coefficient of the reference sunlight of "JIS R 3106: 1998", the value obtained by multiplying the absolute reflectance in the same wavelength band of the standard white plate is averaged, and each wavelength range. It was evaluated as the total reflectance in.

In this embodiment, among the surface materials of the selection candidates, the visible light and solar reflectance of various metal materials are shown in Table 1, the visible light and solar reflectance of various baking coating materials are shown in Table 2, and the visible light and visible reflectance of various wood grain materials are shown. The reflectance of light is shown in Table 3.

In the metal materials shown in Table 1, the solar reflectance was 0.65 to 0.78, and the difference due to the surface treatment was limited. Instead, the difference was visually noticeable due to the glossiness (glossy material, brilliant material). In particular, in the case of the bright material, the metallic feeling peculiar to the aluminum material was strong, and the A6063 material was whitish. In the baking coating materials in Table 2, the Japan Paint Manufacturers Association 2015 standard color for H plate paint is in the range of N1.0 (black) to N9.5 (white), and the solar reflectance is 0.04 to 0.85. rice field. In addition, the neutral color N6.5 (gray) and the brown color similar to wood grain were about 0.3. Visually, a glossy feeling due to the three-part luster for maintaining the weather resistance was slightly felt. In Table 3, in the wood grain material, the solar reflectance of the outdoor specification wood grain films Types A to C was 0.23 to 0.42, and the solar reflectance of the regenerated wood was 0.18. Visually, there was almost no glossiness.

From the above results, in the present embodiment, the wood grain film Type A, which has diffusivity and has a relatively high reflectance, is used for the first member 30 having a diffuse reflection surface because it is in contact with the viewpoint from a human. Were determined. Further, for the second member 40 having the sky reflecting surface, electrolytic polishing (A6063 material + no buff) having a relatively small glossiness, directivity, and relatively high reflectance is used for the surface in contact with the sun's viewpoint. I decided to do it.

Next, a ray tracing simulation is executed (step S13). Here, a forward Monte Carlo ray tracing method is used for a prototype PT having a predetermined shape. By using this Monte Carlo ray tracing method, it is possible to flexibly deal with a system in which complicated shapes, specular reflection, and diffuse reflection are mixed. In addition, the Monte Carlo ray tracing method is performed two-dimensionally from the viewpoint of computational load. Since the feather plate 20 is formed by extrusion molding, it is considered that there is no practical problem even if a two-dimensional simulation is used. The details of the flow of this ray tracing simulation will be described later.

Next, the amount of reflected solar radiation is actually measured using the prototype PT having a predetermined shape (step S14). Here, a prototype PT having a predetermined shape is produced, and the amount of reflected solar radiation is actually measured. In this case, the total amount of solar radiation on the vertical plane, the amount of direct solar radiation on the normal plane, and the amount of solar radiation on the horizontal plane were measured.

Here, in order to measure the upward component of the amount of vertical reflection solar radiation from the prototype PT, a quarter-spherical mask was placed on the upper half of the pyranometer for measurement. Furthermore, in order to eliminate the sky light from the opposite side of the louver installation surface, which is normally blocked, a light-shielding box was installed on the opposite side of the incident side. In addition, in order to exclude the reflected solar heat from other than the louver surface due to the reflection of the feature, a black cloth was laid on the floor surface so that the reflection of short wavelength components would not occur around the pyranometer for reflection measurement. The actual measurements were taken in the summer (early September) and mid-season (late September) on sunny days. In this case, the orientation was just south, and the profile angles in the comparison time zone were 62 ° and 52 °, respectively.

Next, the simulation result and the measured value are compared (step S15). Specifically, the reflected solar radiation amount of the ray tracing simulation calculated using the prototype PT of the feather plate is compared with the measured reflected solar radiation amount. In this case, in the ray tracing simulation, the first member PT30 of the prototype PT used the complete diffusion model described later, and the second member PT40 used the specular reflection model described later. As a result of comparison, the average error rate was as small as 2% in the summer and 4% in the middle period, and the behaviors were almost the same. From the above, it was confirmed that the ray tracing simulation method has high reproducibility.

Then, a parametric model is set (step S16). This parametric model is set based on the shape of the wing plate of the prototype PT. Details of this parametric model will be described later.

<Ray tracing simulation flow>
The flow of the above-mentioned ray tracing simulation will be described.
First, the control unit 51 of the shape design system 50 executes a light source setting process (step S21). Specifically, the simulation unit 512 of the control unit 51 sets the light source to the incident side frontage of the prototype PT (or the blade plate 20). Specifically, from the connection side (P1) between the lower end side surface portion (31) and the bottom portion (32) of the first member PT30 (30) of the upper prototype PT (or wing plate 20), the lower prototype PT (or wing). The vertical surface up to the upper end of the lower end side surface portion (31) of the first member PT30 (30) of the plate 20) is set as the light source.

Next, the control unit 51 of the shape design system 50 executes the setting process of the incident vector (step S22). Specifically, the simulation unit 512 of the control unit 51 uses a vector of the profile angle in the case of direct solar radiation as an incident vector, and uses a vector simulating complete diffusion by the Monte Carlo method in the case of diffuse solar radiation.

Next, the control unit 51 of the shape design system 50 executes the sequential ray tracing process for each division element (step S23). Specifically, the simulation unit 512 of the control unit 51 divides the light source into N elements, and sequentially executes ray tracing for each element. This corresponds to discretizing the total energy on the light source surface into N rays.

Next, the calculation process of the reflection vector and the reflection intensity is executed (step S24). Specifically, the simulation unit 512 of the control unit 51 determines the reflection intensity according to the reflectance of the surface on which the light rays from each element collide according to the incident vector, and the reflectivity property (specular reflection,) of the collision surface. Specify the reflection vector according to directional reflection, perfect diffusion). The details of the reflection model having the reflection property of this reflection vector will be described later. In the original Monte Carlo method, the light rays from the colliding surface are expressed by the emission probability according to the reflectance, but the light ray tracing simulation of the present embodiment is a two-dimensional reflection analysis, and it is considered that visualization is prioritized. However, the appearance probability is not used.

Next, the control unit 51 of the shape design system 50 executes the multiple reflection calculation process (step S25). Specifically, the process of step S24 is performed for each reflective surface, and the calculation is repeated until it finally reaches either the incident surface or the indoor side surface of the louver 10. This is because the light beam is either reflected light that has reached the incident surface of the louver 10 or transmitted light that is directed toward the indoor side.

Next, the control unit 51 of the shape design system 50 executes a process of calculating the transmittance, the reflectance, and the absorption rate (step S26). Specifically, the simulation unit 512 of the control unit 51 aggregates the values on the surface in the transmission or reflection direction for each light ray and calculates them as the transmittance and the reflectance. Then, from the energy conservation law, the difference between the transmittance and the reflectance with respect to 1 is calculated as the absorption rate. Depending on the aggregation, the characteristics of each directivity can be calculated.

<Reflective model>
Next, the reflection model used to calculate the reflection vector described above will be described.
As a feature of the light beam tracing method, the reflectivity is expressed by a random number as a vector corresponding to the solid angle based on the irradiance, and the reflected energy is concentrated in one reflected light from the viewpoint of energy conservation. Therefore, for the reflectance, the average total reflectance of the solar wavelength band measured in Tables 1 to 3 is used, and the reflection vector is calculated using the following equations (1) to (8) using each reflectance property. do.

Here, the following equations (1) and (2) are used as the equations used for the conversion from polar coordinates to XY coordinates.
X = sinθ cosφ… (1)
Y = cosθ ... (2)
Further, as the complete diffuse reflection model, the following equations (3) and (4) are used.

Further, as the specular reflection model, the following equation (5) is used.
R = L-2 (L ・ N) ・ N… (5)
Further, as the directional reflection model (Gaussian function approximation model), the following equations (6) to (8) are used.
R = L-2 (L ・ H) ・ H… (6)

Here, R is a reflection vector, L is an incident vector, N is a normal vector, and H is a half vector of an incident vector (L) and a reflection vector (R). ζ ₁ to ζ ₄ are random numbers, and σ is the standard deviation. θ _r is the angle formed by the normal vector (N) and the reflection vector (R), and φ _r is the azimuth angle of the reflection vector (R). θ _h is the angle formed by the normal vector (N) and the half vector (H), and φ _h is the azimuth angle of the half vector (H).

The vectors in the above-mentioned equations (1) to (8) are unit vectors. In addition to the Gaussian function approximation, the directional reflection can also be used as a Gaussian function approximation and a complete diffuse reflection model.

<Evaluation method of reflected solar radiation>
In the evaluation of the reflected solar radiation amount in step S14 described above, the following equations (9) to (12) are used.

Here, I _{ν_} all * is the vertical total solar radiation [W / m2], I _{ν_} sky * is the horizontal total solar radiation [W / m2], and _{In_} dir * is the normal direct solar radiation [W / m2]. m2] and h are profile angles [deg], and I _{ν_rup} * is the amount of vertical upward reflection insolation [W / m2]. Here, * indicates an item of the measured value. Further, _{In_} dir is the vertical direct reflection solar radiation amount [W / m2], I _{ν_} sky is the sky reflection solar radiation amount [W / m2], and I _{ν_} gro is the feature reflection solar radiation amount [W / m2]. Further, ρ _d is the upward solar reflectance of the vertical direct reflection component, ρ _s is the upward solar reflectance of the sky reflection component, and ρ _g is the upward solar reflectance of the feature reflection component.

<Design of the shape of the blade 20 of the louver 10>
Next, a method of designing the shape of the blade 20 of the louver 10 using the shape design system 50 described above will be described with reference to FIG. 7. Here, each variable of the shape of the parametric model of the feather plate 20 is changed to search for the optimum shape.

<Parametric model>
First, the parametric model set in step S15 will be described with reference to FIG.
The total length of the wing plate 20 in the horizontal direction is defined as RW. Further, each dimension (horizontal length) in the horizontal direction of the wing plate 20 is defined as X1, X2, X3, X4, X5, X6. X1 is the horizontal length of the bottom 32 of the first member 30 of the wing plate 20, X2 is the horizontal length of the first diffusion surface portion 33, X3 is the horizontal length of the connecting portions 35 and 45, and X4 is the second sky reflecting portion 42. X5 is the horizontal length of the upper surface portion 38 of the first member 30. The sum of the horizontal lengths X4 and X5 corresponds to the length of the second diffusion surface portion 36 of the first member 30. Further, X6 is the horizontal length of the lower end engaging portion 31a of the first member 30 (horizontal length from the end portion of the blade plate 20 to the lowest position of the first sky reflecting portion 41).

X1, X3, X5 are constants, and X2, X4, X6 are expressed by the following equations.
X2 = (RW-X1-X3-X5) × δ… (21)
X4 = RW- (X1 + X2 + X3 + X5) ... (22)
X6 = X1 × m ... (23)
Here, δ is a variable and m is the diffusion surface hoisting rate.

Further, the vertical dimension (height) of the wing plate 20 is defined as Y1, Y2, Y3, Y4, Y5, Y6, Y7. Y1 is the height of the first diffusion surface portion 33 of the first member 30, Y2 is the height of the second diffusion surface portion 36, and Y3 is the height from the connecting portion 45 of the second member 40 to the lower end of the second sky reflection portion 42. , Y4 is the height of the second sky reflecting portion 42. Y5 is the height of the vertical portion of the lower end side surface portion 31 of the first member 30, and Y6 is the height from the uppermost position of the vertical portion of the lower end side surface portion 31 of the first member 30 to the lowest position of the first sky reflection portion 41. , Y7 is the height of the upper side surface portion 37 of the first member 30.

Y5 and Y7 are constants, and Y1 to Y4 and Y6 are represented by the following equations.
Y1 = RW × tan θ × α… (24)
Y2 = RW × tan θ × (1-α) × β… (25)
Y3 = RW × tanθ × (1-α) × (1-β) × γ… (26)
Y4 = RW × tanθ- (Y1 + Y2 + Y3) ... (27)
Y6 = (Y1 + Y2-Y5) x m ... (28)

Further, the inclination angle θ of the wing plate 20 is such that the connection side P1 between the bottom portion 32 of the first member 30 and the lower end side surface portion 31 and the upper surface portion 38 and the upper side surface portion 37 of the first member 30 with respect to the horizontal plane. This is the angle formed by the line L1 connecting the connection side P2 in the feather plate 20.

Further, the distance between the wing plates 20 is defined by using the total length RW in the horizontal direction of the wing plates 20 and the allowable incident angle φ. The allowable incident angle φ is a connection side P1 between the bottom portion 32 of the first member 30 and the lower end side surface portion 31 and a connection side P2 between the upper surface portion 38 and the upper side surface portion 37 of the first member 30 with respect to the horizontal plane. This is the angle formed by the line L2 connected in space.
Of the above-mentioned dimensions, the setting constants used when designing the feather plate 20 in the present embodiment are shown in Table 4, and the design variables and the range and step of the variables are shown in Table 5. Note that sp3 and sp4 in FIG. 8 indicate design variables of the reflectance and the reflection characteristics of the corresponding surfaces, similarly to sp1 and sp2.

<Shape design method>
Next, a method of designing the shape of the blade 20 of the louver 10 using the shape design system 50 described above will be described with reference to FIG. 7.

First, the control unit 51 of the shape design system 50 executes an acquisition process of louver installation information (step S31). Specifically, the condition specifying unit 511 of the control unit 51 acquires information (latitude and direction of the installation location) regarding the installation location of the louver 10. Further, the condition specifying unit 511 specifies a period and a time zone to be evaluated. In the present embodiment, the summer and intermediate periods (spring or autumn) are set as the evaluation target period, and 11:00 to 15:00 is set as the evaluation target time zone.

Next, the control unit 51 of the shape design system 50 executes the acquisition process of the solar radiation condition (step S32). Specifically, the condition specifying unit 511 of the control unit 51 acquires the solar zenith angle and the amount of solar radiation according to the latitude of the installation location in the period and time zone to be evaluated from the meteorological information server 57. Then, using a known model (Udagawa model + Isotropic model), the total amount of solar radiation on the horizontal plane is directly dispersed and separated from the acquired amount of solar radiation and the solar zenith angle, and each incident vector is generated.

Next, the control unit 51 of the shape design system 50 executes a process of calculating the period weighting coefficient (step S33). Specifically, the condition specifying unit 511 of the control unit 51 aggregates the amount of vertical direct solar radiation during the period and time zone to be evaluated for each profile angle, and the ratio (weight coefficient) of the vertical direct solar radiation to the integrated value. Is calculated.

Next, the control unit 51 of the shape design system 50 executes the ray tracing simulation process (step S34). Specifically, the simulation unit 512 of the control unit 51 executes the ray tracing simulation shown in FIG.

Next, the control unit 51 of the shape design system 50 executes the evaluation process of the period average optical characteristics (step S35). Specifically, the shape optimization unit 513 of the control unit 51 multiplies the optical characteristics calculated in step S33 by a weighting coefficient and evaluates them as average optical characteristics during the evaluation period.

Next, the control unit 51 of the shape design system 50 executes the shape optimization process (step S36). Specifically, the shape optimization unit 513 of the control unit 51 changes the design variable in variable increments within the variable range by using the multipurpose genetic algorithm in the parametric model described above. Here, as a search condition, a Pareto solution search with "high sky reflectance" and "high aperture ratio" is performed. In this Pareto solution search, the control unit 51 of the shape design system 50 repeatedly executes the processes after step S34 every time the design variable is changed.

In FIG. 9, the Pareto solution when the louver 10 is installed in the south direction in Tokyo is indicated by a dark circle. In FIG. 9, the solutions that do not satisfy the search conditions are indicated by light gray circles as inferior solutions.

Then, when a plurality of Pareto solutions are obtained within the variable range of the design variable, the shape optimization unit 513 identifies the solution having the highest sky reflectance among the Pareto solutions as the optimum solution.
Then, the control unit 51 of the shape design system 50 executes the output processing of the optimized shape (step S37). Specifically, the shape optimization unit 513 of the control unit 51 generates the shape of the feather plate 20 having the value specified as the optimum solution as a design variable, and displays it on the display screen of the output unit 58. In this case, the shape displayed on the screen is the shape of the blade 20 in FIG. 2.

<Reflected light trajectory and optical characteristics before and after optimization>
10 (a) to 10 (c) show the reflected light locus of the prototype PT of the wing plate before optimization for each incident angle, and FIGS. 10 (d) to 10 (f) show the wing after optimization. The reflected light locus for each incident angle of the plate 20 is shown. In FIGS. 10A to 10F, the thick straight line between the frontages on the incident side of the blade plate 20 is the set light source.
Further, it can be seen that after the optimization, the shape is changed so that the reflection performance due to the single reflection is improved instead of the multiple reflection.

FIG. 11 shows the optical characteristics of direct solar radiation before and after optimization. FIG. 11A shows the optical characteristics of the reflection component, and FIG. 11B shows the optical characteristics of the transmission component. Here, the optical characteristics are used as the vertical face reference. In the reflection component shown in FIG. 11A, the recursive component increased by about 3.2 times and the upward component increased by about 5.6 times when the incident angle in summer was high (incident angle of 60 ° or more). In the permeation component shown in FIG. 11B, the upward component was significantly reduced, and the heat-shielding component was the main component. Further, since the allowable incident angle was set to 30 ° under the calculation conditions, the transmittance below that was rapidly increased.

<Shape of louver 10 wing plate 20 according to installation location>
FIG. 12 shows the outer cross-sectional shape of the feather plate 20 on which the louver 10 is installed in various places of Okinawa, Kagoshima, Osaka, Tokyo, Sendai, and Sapporo. The shapes of the feather plates 20 are the result of designing using the shape design system 50 described above.

The shape of the wing plate 20 outside the cross section is due to the distribution of the direct solar radiation weight coefficient (ratio of the integrated solar radiation amount) for each incident angle during the evaluation target period.
Here, Table 6 below shows the direct solar radiation weighting factors for each incident angle in the summer / intermediate period (evaluation target period) in each region.

As shown in Table 6, in Okinawa, the direct solar radiation weighting coefficients for each incident angle of 40 to 50 degrees and 60 to 65 degrees are high. For this reason, in Okinawa, the shape is such that direct sunlight is mainly reflected in the sky at solar altitudes of 40 to 50 degrees and 60 to 65 degrees. Specifically, as shown in FIG. 12, the gradient of the second sky reflecting portion 42 of the second member 40 of the feather plate 20 is steep, and the first sky reflecting portion 41 of the second member 40 of the feather plate 20 is long. It becomes a shape.

As shown in Table 6, in Kagoshima, the direct solar radiation weighting coefficient for each incident angle is high in a wide range centering on the incident angle of 50 degrees. Therefore, in Kagoshima, the shape is such that direct sunlight is widely reflected in the sky around the solar zenith angle of 50 degrees. Specifically, as shown in FIG. 12, the gradients of the first sky reflecting portion 41 and the second sky reflecting portion 42 of the second member 40 of the feather plate 20 have a flat shape at substantially the same angle.

Further, in Osaka, Tokyo and Sendai, the direct solar radiation weighting coefficient for each incident angle is high in the two ranges of the incident angle of 30 degrees to 45 degrees and 65 degrees to 75 degrees, which is polarized. Therefore, it is desirable to reflect on the left side and the right side of the upper surface of the blade plate 20 in a well-balanced manner. Therefore, the shape is such that reflection is performed on both the left side and the right side of the blade plate 20.

Further, in Sapporo, the direct solar radiation weighting coefficient for each incident angle is high in the range where the incident angle is high (50 degrees to 70 degrees). Therefore, in these areas, it is desirable to reflect only on the left side because the sunlight does not reach the right side of the louver very much. Therefore, the left side of the wing plate 20 has a short shape.
Further, it is preferable that the second sky reflecting portion 42 of the feather plate 20 in Sapporo is formed by baking coating (white). Since the second sky reflecting portion 42 has a shape with a gradient that is almost flat, the sky reflectance can be increased by performing diffuse reflection using a baking finish (white).

According to this embodiment, the following effects can be obtained.
(1) The louver 10 of the present embodiment is provided with a plurality of wing plates 20 extending in the horizontal direction, which are inclined and arranged side by side in the vertical direction. The first member 30 of the feather plate 20 includes a first diffusion surface portion 33 having a diffusion reflection surface, a second diffusion surface portion 36, an upper side surface portion 37, and an upper surface portion 38. The second member 40 of the wing plate 20 includes a first sky reflecting portion 41 having a sky reflecting surface and a second sky reflecting portion 42. As a result, the sunlight received by the louver 10 is reflected to the sky to reduce the reflection to the surrounding buildings and the ground, so that the thermal environment around the building in which the louver 10 is provided can be improved. Further, since the transmitted light from the diffuse reflection surface of the upper side surface portion 37 and the upper surface portion 38 enters the indoor side, the glare due to the reflection can be reduced, and a human-friendly visual environment can be realized.

(2) The feather plate 20 of the present embodiment includes a first member 30 and a second member 40 having two different reflection characteristics. As a result, the feather plates 20 having different reflection characteristics can be manufactured.

(3) The feather plate 20 of the present embodiment is a sky reflectance ratio and a solar radiation shielding device on a sky reflecting surface based on the solar altitude and the amount of solar radiation at the place where the louver 10 is installed and the optical characteristics calculated by the ray tracing method. It is composed of a shape that increases the aperture ratio of. As a result, a large amount of solar radiation incident on the feather plate 20 can be reflected in the sky.

(4) In the feather plate 20 of the present embodiment, the surface of the lower end side surface portion 31 is composed of a diffuse reflection surface. This makes it possible to realize a visual environment that is friendly to people outside the building.
(5) In the feather plate 20 of the present embodiment, the second member is internally fitted to the first member 30 including the upper side surface portion 37 and the upper surface portion 38. Thereby, the two members can be integrated to form the blade plate 20.

(6) The first member 30 and the second member 40 of the wing plate 20 of the present embodiment include connecting portions 35 and 45 through which the connecting rod 15 for connecting the wing plates 20 is penetrated. This makes it possible to reliably support the plurality of feather plates 20.

(7) The control unit 51 of the shape design system 50 of the present embodiment executes a louver installation information acquisition process (step S31) and a solar radiation condition acquisition process (step S32). In this case, in a parametric model that determines the shape of the wing plate 20, a simulation in which the angle and length of the sky reflecting surface in the shape are changed to calculate the sky reflectance in the sky reflecting surface and the aperture ratio of the solar radiation shielding member. Is repeated to determine the shape of the wing plate 20 in which the sky reflectance and the aperture ratio are increased. As a result, it is possible to design a shape in consideration of sky reflectivity and aperture ratio even when the solar radiation condition is different depending on the installation area and installation location of the louver.

(8) The control unit 51 of the shape design system 50 of the present embodiment executes the shape optimization process by using the multipurpose genetic algorithm. This makes it possible to efficiently design the shape of the blade plate 20.

(9) The control unit 51 of the shape design system 50 of the present embodiment executes the shape optimization process using the period weighting coefficient. This makes it possible to evaluate in consideration of the average optical characteristics during the evaluation period.

Moreover, the above-mentioned embodiment may be changed as follows.
The louver 10 of the above embodiment supports a plurality of blade plates 20 by connecting rods 15 penetrating the central portion of the blade plates 20 arranged in the vertical direction. The method of supporting each feather plate 20 is not limited to this, and each feather plate 20 may be connected by arranging a connecting rod at the upper end portion or the lower end portion. Further, the connection is not limited to the case of connecting with a connecting rod, and a flexible member may be used for connecting.

The first member 30 of the feather plate 20 of the above embodiment is configured by attaching a wood grain film to the surface of the A6063 material, and the second member 40 electrolytically polishes the surface of the A6063 material (without buffing). Constructed by doing. The first member 30 is not limited to the material (material) and shape as long as it is composed of a surface having diffuse reflection (diffuse reflection surface), and the second member is also a surface having sky reflection (sky reflection). It suffices if it is composed of faces).

In the blade plate 20 of the above embodiment, the support portion 43 of the second member 40 is engaged with the ridge portion 32a of the first member 30, and the central engaging portion 46 of the second member 40 is fixed to the first member 30. The portion 36a and the fitting portion 36b were engaged with each other, and the upper end engaging portion 47 of the second member 40 was engaged with the reinforcing portion 39 of the first member 30. The configuration for engaging the second member 40 with the first member 30 is not limited thereto.

The wing plate 20 of the above embodiment has the shape shown in FIG. 8 and was designed using a parametric model in which the design constants in Table 4 and the design variables in Table 5 are set. The shape, design constants, and design variables of the parametric model used for the shape of the wing plate 20 are not limited to the above parametric model, and any shape, constants, and variables may be used.

The control unit 51 of the shape design system 50 of the above embodiment executed the shape optimization process using a near-culture type genetic algorithm as a multi-objective optimization algorithm. The control unit 51 may specify the optimum shape by using another algorithm.

θ ... tilt angle, φ ... allowable incident angle, P1, P2 ... connection side, PT ... prototype, RW ... total length, PT30, 30 ... first member, PT33, 33 ... first diffusion surface portion, PT36, 36 ... second diffusion Face portion, PT40, 40 ... 2nd member, PT41, 41 ... 1st sky reflector, PT42, 42 ... 2nd sky reflector, 10 ... louver, 15 ... connecting rod, 20 ... feather plate, 21 ... cap, 30 ... 1st member, 31 ... lower end side surface portion, 31a ... lower end engaging portion, 32 ... bottom portion, 32a ... ridge portion, 35, 45 ... connecting portion, 36a ... fixed portion, 36b ... fitting portion, 37 ... upper side surface portion , 37a ... opening, 38 ... top surface, 39 ... reinforcement, 41a ... tip, 43 ... support, 44 ... connection, 46 ... central engagement, 47 ... top engagement, 50 ... shape design system , 51 ... Control unit, 53 ... Parametric model storage unit, 56 ... Input unit, 57 ... Meteorological information server, 58 ... Output unit, 511 ... Condition specification unit, 512 ... Simulation unit, 513 ... Shape optimization unit.

Claims (5)

A solar shielding device in which a plurality of solar shielding members extending in the horizontal direction are tilted so as to be higher on the indoor side and arranged in the vertical direction.
The outdoor surface of the solar radiation shielding member is provided with a sky reflecting surface having a property of reflecting incident solar radiation in the direction of the sky within a predetermined range angle with respect to the incident angle.
A solar shielding device characterized in that diffuse reflecting surfaces are provided on the indoor side surfaces, upper surfaces, and lower surfaces of the solar shielding member at positions that do not interfere with the action of the sky reflecting surface that reflects the solar radiation to the heavens. It is a solar shielding member that is tilted so that the indoor side is high, and a plurality of vertical shielding devices are arranged side by side to form a solar shielding device, which extends horizontally.
The outdoor surface is provided with a sky reflecting surface having the property of reflecting incident solar radiation in the direction of the sky within a predetermined range with respect to the incident angle, and the side surface, upper surface and lower surface on the indoor side are provided with a sky reflecting surface. A solar radiation shielding member characterized in that a diffuse reflection surface is provided at a position that does not interfere with the action of the sky reflection surface that reflects the sunlight to the sky. A first member having a member constituting the indoor side surface, the upper surface and the lower surface provided with the diffuse reflection surface and the outdoor side surface is provided with a member constituting the surface of the sky reflecting surface. The solar radiation shielding member according to claim 2, wherein the two members are fitted and configured. The solar shielding member according to claim 2 or 3, wherein a connecting portion to which a connecting member to be connected to the other solar shielding member is attached is provided on a part of the upper surface. It is a design method that uses a computer to design a solar shielding device in which a plurality of solar shielding members extending in the horizontal direction are tilted so as to be higher on the indoor side and are provided side by side in the vertical direction.
The solar radiation shielding member has a sky reflecting surface having a property of reflecting incident solar radiation in the direction of the sky within a predetermined range angle with respect to the incident angle on the outdoor surface, and the side surface on the indoor side. The upper surface and the lower surface have diffuse reflection surfaces at positions that do not interfere with the action of the sky reflection surface that reflects the solar radiation to the sky.
The computer
In a parametric model that determines the shape of the sun-shielding member, a simulation that changes the angle and length of the sky-reflecting surface in the shape to calculate the sky reflectance on the sky-reflecting surface and the aperture ratio of the sun-shielding member. Repeat,
The calculation result in which the angle and length of the sky reflecting surface used in the simulation and the calculated sky reflectance and the aperture ratio are associated with each other is stored.
A method for designing a solar radiation shielding device, which comprises determining the shape of the solar radiation shielding member based on the magnitudes of the sky reflectance and the aperture ratio in the calculation result.

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