JP2002039977A - Method for measuring heat quantity of heat shield part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine a correct reduction rate of an overall heat transfer quantity by calculating a heat quantity load finely to conform to the reality. SOLUTION: There is provided the method for measuring effects of the heat shield paint. According to the method, after a color of the paint is determined, a solar factor defined by JIS A5759 of this paint is measured, and a solar absorptance is calculated from the measured solar factor. An equivalent ambient temperature is calculated on the basis of the solar absorptance by an equation A of the equivalent ambient temperature = a temperature + a solar radiation × the solar absorptance/20. Moreover, a break-through heat quantity is calculated by an equation B of the break-through heat quantity = a K value × an area × (the equivalent ambient temperature - a room temperature) wherein the K value (thermal resistance) is an overall heat transfer coefficient of a material to be painted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a calorific value of a paint for shielding solar heat.

[0002]

2. Description of the Related Art The applicant of the present application previously covers the outer surfaces of various structures, ships, buildings, automobiles, home electric appliances, etc. on land and at sea, which are exposed to the solar radiation, and suppresses the rise in the internal temperature thereof. By reducing air-conditioning costs or evaporative loss of contents, it is possible to expect a remarkable effect on energy saving, and it has excellent long-term durability, no environmental health problems, and can be colored and aesthetically pleasing. A solar heat-shielding paint that has the function of providing a predetermined solar heat-shielding effect without increasing the film thickness. Further, by using an organic pigment, the color can be given a wide range. Invented a solar heat shielding paint that can realize any color without being limited to, and even a dark color, and a clear color tone,
This was filed as a patent application as Japanese Patent Application No. 11-17046.

[0003] The solar heat shielding paint disclosed in Japanese Patent Application No. 11-17046 is all of the top coat, middle coat, undercoat and electrodeposition coating systems, or of the top coat, middle coat, undercoat and electrodeposition all coating systems. The intermediate paint or a partial paint excluding the top coat is mainly composed of a pigment and a vehicle. The pigment reflects in the near infrared region, and has a solar reflectance of 15% or more as defined in JIS A5759. And CIE 1976
The gist of the present invention is to apply a solar heat shielding paint obtained by mixing a plurality of organic or organic and inorganic solar heat coloring pigments having an L * value of 20 or less in an L * a * b * color space.

According to this solar heat shielding paint, a remarkable effect is observed at the surface temperature. By covering the outer surfaces of ships and various buildings which are directly exposed to the sun, the solar heat is shielded for a long time, and the rise in the internal temperature is reduced. It is possible to improve the air-conditioning cost or suppress the evaporative consumption of the contents, thereby making it possible to apply solar heat shielding paint and its coating, which can be expected to have a remarkable effect on energy saving, and contribute to industrial development. However, there is something very large.

[0005] In addition to this, it is possible to exhibit a predetermined solar heat shielding effect without increasing the film thickness so much, and it is possible to give a wide range of colors by using an organic pigment.
Furthermore, to any color without being limited to black and gray,
In addition, it is possible to realize dark colors and clear color tones.

[0006] In the case where such a solar heat shielding paint is applied to a building to obtain the effect, it is important to determine the amount of the applied paint and the heat shield effect. . This is because it is more desirable to increase the maximum heat shielding effect with a small amount of coating.

[0007] The solar heat shielding effect in a building can be regarded as a cooling sensible heat load. The cooling sensible heat load is the sum of the heat loads generated by the following factors. (1) Heat flow through the wall due to temperature difference between inside and outside Wall area * Heat transfer rate * Temperature difference between inside and outside (2) Heat flow through the wall due to sunlight Wall area * Heat transfer rate * Equivalent outside temperature rise (3) Window penetration due to sunlight Heat Window area * Window shielding coefficient * Incident solar radiation (4) Ventilation heat due to temperature difference between inside and outside * Ventilation volume * 0.3 (specific heat of air volume) * Temperature difference between inside and outside (5) Heat generated inside the building Equipment capacity (kw) * Usage rate * 860 number of people * room occupancy rate * human metabolism Of these, the heat flowing through the wall of (1) and (2) is related to the thermal barrier paint.

The equivalent outside air temperature rise Δθ _e appearing in the equation for calculating the heat flowing through the wall due to the solar radiation in (2) is as follows: Here, α: solar radiation absorption rate α on the wall surface. : Heat transfer coefficient of outer surface (ordinary value: 20.0 kcal / m)
² h ° C.) J: It is expressed by the amount of incident solar radiation (kcal / m ² h).
indicates that equivalent to that raised by theta _e.
This and the true outside temperature θ. The combination of the above is referred to as “equivalent outside air temperature θ _E ”. θ _E = θ. + Δθ _E (2)

The heats flowing through the two walls (1) and (2) are added together by introducing a considerable outside air temperature. Here, it is usual to calculate in the form of θ _U : outside air temperature θ _R : indoor temperature.

[0010]

FIG. 6 shows a conventional example of a method of calculating the amount of heat flowing through a roof surface. Conventionally, the solar radiation absorption rate α appearing in the equation (1) is calculated by the conventional heat load calculation method. , Α = 0.8 has been used. This value is based on the absorption rate of the concrete or mortar surface, and until now there was not much idea of intentionally controlling the solar radiation absorption rate on the outer wall surface, so apply this value to all building material surfaces. There was no problem.

However, in the case of a thermal barrier paint such as the solar thermal shield paint of Japanese Patent Application No. 11-17046, it has become necessary to deal with the solar absorptivity more strictly.

[0012] The object of the present invention in view of such circumstances,
It is an object of the present invention to provide a method for measuring the calorific value of a thermal barrier paint, which can calculate a precise calorific value load in accordance with an actual situation and can determine an accurate reduction rate of a heat flow rate.

[0013]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention determines the coating color of a paint and then determines the JI of the paint.
The solar reflectance defined in SA5759 is measured, the solar absorptance is calculated from the measured solar reflectance, the corresponding outside air temperature is calculated by the following formula A based on the solar absorptance, and further the following formula B is calculated. The gist is to calculate the once-through heat quantity by using Formula A: Equivalent outdoor temperature = air temperature + solar radiation x solar absorptivity / 20 Formula B: once-through heat = K value x area x (equivalent outdoor temperature-room temperature) where K value (heat flow resistance) is the heat flow of the material to be coated. rate

According to the first aspect of the present invention, the solar absorptance, for which a fixed value has been used conventionally, is measured by measuring the solar reflectance and calculating from the measured solar reflectance. It is possible to calculate the calorific load for the heat shielding effect peculiar to the paint, which occupies the outer surface of the building material, in a detailed manner.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory view showing one embodiment of the method for measuring the effect of the thermal barrier paint of the present invention, and FIG. 2 is a vertical sectional front view of the same, showing a method of calculating the amount of heat flowing from the roof surface.

As shown in FIG. 1, in the present invention, after determining the paint color, the solar reflectance of this paint defined in JIS A5759 is measured. Then, the solar absorptivity is calculated from the measured solar reflectance.

Regarding the measurement of solar reflectance, JIS A5
759, using a spectrophotometer at a wavelength of 350 m
from m to 2100 mm at intervals of 50 mm
The spectral transmittance (Rλ _i ) at the wavelength point is measured ( ² ), and the solar reflectance is calculated by the following equation, or the direct solar reflectance is obtained using a reflectometer. Here, R _E : solar transmittance (%) Eλ _i : value of spectral distribution of solar radiation Rλ _i : spectral reflectance However, a film whose spectral reflectance distribution curve shows a vibration waveform has an average passing between the peak and the valley. Typical distribution curve,
The spectral reflectance at each wavelength is calculated. Note ( ² ) When measuring Rλ _i ,
It is attached at an angle of 0 degrees so that the specularly reflected light is captured by the integrating sphere.

In order to calculate the solar absorptivity from the solar reflectance, the reciprocal may be obtained. For example, the solar reflectance β is β = 0.2
In this case, the solar absorptivity α is 0.8. (See comparison between FIG. 2 and FIG. 6)

Based on the solar radiation absorption rate, the equivalent external temperature is calculated from the formula A: Equivalent outdoor temperature = air temperature + solar radiation quantity × solar absorption rate / 20.

Further, formula B: once-through heat = K value × area ×
The through heat is calculated from (equivalent outside air temperature-room temperature).

Here, the K value (heat transmission resistance) is the heat transmission coefficient of the material to be coated (roof material). 1/20 External heat transmission resistance (external transmission coefficient) [R0] Heat transmission resistance of coating film (thickness) / Heat transfer coefficient) [R1] Heat flow resistance of steel plate (roof material) (thickness / heat transfer coefficient) [R2] Heat flow resistance of heat insulating material (thickness / heat transfer coefficient) 1/10 Internal heat flow resistance ( Internal transmission rate) [R3]

2 and 6, the external heat transmission resistance of R0 is 1
/ 20, and the heat flow resistance of the coating film of R1 is the thickness L of the coating material.
1 and the thermal conductivity of the paint, and the heat flow resistance of the steel plate (roof material) of R2 is represented by the thickness L2 of the steel plate (roof material).
And the thermal conductivity of the steel plate (roof material) (if there is a thermal insulator, the thickness of the thermal insulator and the thermal conductivity of the thermal insulator are involved), and the internal conductivity of R3 is 1/10. R0 and R3 are fixed numerical values.

A case study was conducted on the influence of the solar absorptivity on the heat load based on the data of the solar heat shield paint (heat shield paint) and the general paint of Japanese Patent Application No. 11-17046. Table 1 below shows the solar absorptivity data of various coatings.

[0024]

[Table 1]

The solar absorptivity data is based on JI
The solar reflectance defined in SA5759 was measured, and the solar absorptance was calculated from the measured solar reflectance.

According to the "Air Conditioning Sanitation Engineering Handbook" edited by the Society of Air Conditioning Sanitation Engineers, the ambient weather conditions for cooling design in Tokyo are as shown in Table 2 below. (Chapter 2 of the same book air-conditioning equipment).

[0027]

[Table 2]

Based on Table 2 above, the equivalent outside air temperature when the roof (horizontal surface) is coated with the characteristics shown in Table 1 is calculated as shown in FIG. According to the results, white has no significant difference from the thermal barrier coating due to the high solar reflectance even in a general coating, but in a coating having a color tone such as black and gray, 10 to 10 in the dawn time
A considerable decrease in the outside air temperature of about 15 ° C. is observed.

The heat flowing through the wall is calculated by the above equation (3).
There is a horizontal roof with an area of 1000 m ² , which is to be subjected to six types of surface painting of Case Study 1. The roof structure is non-insulated (K = 8.00 kcal / m ² h ° C.), insulated (insulation thickness: 50 mm, K = 0.503 kcal / m)
² h.degree. C.). It is assumed that the inside of the building is controlled to a room temperature of 26 ° C.

FIG. 4 shows the amount of heat flowing through the roof from the above conditions. As you can see at a glance,
Thermal barrier coating is not comparable to thermal insulation with a thickness of 50 mm. However, when compared with general paint under the same heat insulation condition,
About 20% for white, 30-4 for gray and black
A decrease in the amount of heat flowing through by 0% (daylight time) is observed.

The relationship between cooling load and natural temperature is 50
m, north and south 20m (floor area 1000m² ), Eave height 5m
Assuming a warehouse-like building, the roof is non-insulated and insulated,
-A total of 4 types of combinations of general paint and thermal barrier paint
I can. For the walls other than the roof, the same insulation as the roof,
The solar radiation absorption rate is 0.8. Next, the ventilation volume of this house
[M³/ H], the natural room temperature θ in the building_R[℃]
IsHere, Q: Cooling heat load of the entire building [kcal / h] Right side denominator: Total heat transmission rate of the building [kcal / h ° C] The number of ventilation is 1, 10 [times / h]
In addition, the cooling load Q for the eight cases shown in Table 1
As a result of calculation, when looking at the ventilation rate l times / h,
20 to 25% reduction in cooling load at daytime
It has become. On the other hand, in case of 10 times / h ventilation
The temperature of the outside air is dominant.
Is relatively small. Still general painting + unapproved
The effect of about 5 ° C was seen with heat and thermal barrier coating + heat insulation.

[0032]

As described above, the method for measuring the calorific value of the thermal barrier paint according to the present invention is capable of accurately calculating the calorific load in accordance with the actual condition and determining the accurate heat-penetrating flow reduction rate. is there.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a method for measuring the calorific value of a thermal barrier paint according to the present invention.

FIG. 2 is a vertical sectional front view showing one embodiment of the method for measuring the calorific value of the thermal barrier paint of the present invention.

FIG. 3 is a graph of an equivalent outside air temperature.

FIG. 4 is a graph showing a comparison of a once-through heat load from a roof surface.

FIG. 5 is a graph showing natural room temperature.

FIG. 6 is a vertical sectional front view showing a conventional example.

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[Procedure amendment]

[Submission date] February 1, 2001 (2001.2.1)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction contents]

Here, the K value (heat transmission resistance) is the heat transmission coefficient of the material to be coated (roof material). 1/20 External heat transmission resistance (external transmission coefficient) [R0] Heat transmission resistance of coating film (thickness) / Thermal conductivity) [R1] Heat flow resistance of steel plate (roof material) (thickness / thermal conductivity) [R2] Heat flow resistance of heat insulating material (thickness / thermal conductivity) 1/10 Internal heat flow resistance ( Internal transmission rate) [R3]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Change

[Correction contents]

2 and 6, the external heat transmission resistance of R0 is 1
/ 20, and the heat flow resistance of the coating film of R1 is the thickness L of the coating material.
1 and the thermal conductivity of the paint, and the heat flow resistance of the steel plate (roof material) of R2 is represented by the thickness L2 of the steel plate (roof material).
And the thermal conductivity of the steel plate (roof material) (if there is a thermal insulator, the thickness of the thermal insulator and the thermal conductivity of the thermal insulator are involved), and the internal heat flow resistance of R3 is 1/10. . R
0 and R3 are fixed numerical values.

[Procedure amendment 3]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

Claims (1)

[Claims] After determining the paint color of the paint, the solar reflectance defined in JIS A5759 of the paint is measured,
Calculating a solar absorptance from the measured solar absorptance, calculating an equivalent outside air temperature by the following equation A based on the solar absorptivity, and further calculating a once-through calorie by the following equation B A method for measuring the calorific value of paint. Formula A: Equivalent outdoor temperature = air temperature + solar radiation x solar absorptivity / 20 Formula B: once-through heat = K value x area x (equivalent outdoor temperature-room temperature) where K value (heat flow resistance) is the heat flow of the material to be coated. rate