Top plate temperature drop laminated sheet for outdoor unit of air conditioner

Abstract

To provide means for solving a trade-off that occurs when attempting to simultaneously block sunlight and utilize the heat of vaporization of water by one means in order to lower a temperature of a top plate of an outdoor unit of an air conditioner.SOLUTION: Even when a laminated sheet is porous, just a few sheets laminated together provide sufficient shading against sunlight; because only a few porous sheets are laminated together, it has a large surface area necessary for water evaporation; because only a few porous sheets are laminated together, a water evaporation surface is close to a top plate of an outdoor unit of an air conditioner; and the laminated sheet, which makes it easier for vaporization heat to be transferred to the top plate of the outdoor unit of the air conditioner, is installed on the top plate in a state of being constantly wet with water, so that it is possible to significantly reduce a temperature of the top plate of the outdoor unit of the air conditioner, which is exposed to the natural environment.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a laminated sheet for lowering the top plate temperature of an air conditioner outdoor unit. Specifically, it relates to a method for enhancing the energy efficiency of an air conditioner during cooling and dehumidifying operations, i.e., the so-called effectiveness of the air conditioner, by lowering the top plate temperature of the air conditioner outdoor unit. In the heat transfer of the top plate of the air conditioner outdoor unit, two functions are simultaneously realized by a simple means: blocking the inflow of sunlight, which is one of the main inputs, and discharging heat by utilizing the latent heat of vaporization of water as an output, thereby significantly lowering the top plate temperature of the air conditioner outdoor unit compared to the state before installing the laminated sheet for lowering the top plate temperature of the air conditioner outdoor unit.

Background Art

[0002] Global warming (the boiling of the earth) is progressing, and air conditioners are becoming necessities for protecting lives. Inevitably, this has led to an increase in the total number of installed air conditioners, an increase in the operating hours per unit, a decrease in energy efficiency, and poor effectiveness of air conditioners, resulting in an economic burden due to increased power consumption, concerns about the stable supply of electricity, and an environmental load, which has become an important issue for both individuals and society as a whole. Energy conservation of air conditioners has been studied in various ways from both the manufacturing and usage aspects and is evolving daily. From the usage aspect, effective energy conservation measures that can be taken from the perspective of using air conditioners have been introduced.

[0003] Specifically, measures such as devising the installation location of the air conditioner outdoor unit, installing sunshades, panels, and covers to avoid direct sunlight, suppressing the inflow of heat such as ensuring the air flow at the outdoor unit outlet, and active measures using water are recommended (see Non-Patent Document 1).

[0004] In addition, a proposal has been made to install a device for cooling with water near the air conditioner outdoor unit. A method has been proposed to cool the top plate of the air conditioner outdoor unit by using a water-absorbing sheet to hold the water to be vaporized and utilizing the large latent heat of vaporization of water (see Patent Document 1).

[0005] A method has been proposed that utilizes the latent heat of vaporization of cooling water to cool the air sucked into the intake port of the outdoor unit of an air conditioner, thereby improving the efficiency of heat exchange that occurs between the cooled intake air and a heat exchanger (see Patent Document 2 and Patent Document 3).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Non-Patent Documents

[0007]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] In the technology described in Non-Patent Document 1, measures for improving the performance of air conditioners are recommended, but survey data on how widespread these measures are in society cannot be found. Furthermore, although it is possible to observe the installation status of air conditioners on the street without difficulty, these various measures do not seem to be widely spread in society.

[0009] Not only is it not widespread, but some of the countermeasures in Non-Patent Document 1 have fundamental limitations. In the case of sunshades, panels, covers, etc. to avoid direct sunlight, it is fundamentally impossible to lower the top plate temperature below the air temperature of the environment where the air conditioner outdoor unit with these countermeasures is installed. Also, even when a countermeasure such as installing the air conditioner outdoor unit on the north side of the building is taken, there is a problem that at noon on a midsummer day when the power demand is the most severe, direct sunlight shines from directly above, and there is also a problem that it is fundamentally impossible to lower the top plate temperature below the air temperature of the environment where the air conditioner outdoor unit is installed.

[0010] On the other hand, the active countermeasure using water in Non-Patent Document 1 can be expected to have a great effect if implemented. Non-Patent Document 1 states that "During hot days such as sweltering days, when the outdoors is hot, spraying water directly on the outdoor unit or splashing water around it makes it easier to maintain the cooling efficiency. When spraying water on the outdoor unit, it is most effective to spray it on the aluminum fins on the back, but it may be difficult to spray depending on the installation method and the type of outdoor unit. In that case, even just spraying an appropriate amount on the top plate is effective." However, the method using water is very laborious as long as it depends on manual labor, and there is a problem that it is not a constant countermeasure.

[0011] The prior art described in Patent Document 1 states that a water-absorbing sheet can be used to hold the water to be vaporized and utilize the large heat of vaporization of water to cool the top plate of the air conditioner outdoor unit. However, although the characteristics of the water-absorbing sheet are very important to obtain sufficient heat of vaporization, this point is not mentioned at all, and it has to be said that it lacks specificity. Also, Patent Document 1 attempts to lower the top plate temperature of the air conditioner outdoor unit only by the heat of vaporization.

[0012] In the prior arts described in Patent Document 2 and Patent Document 3, there is a method of using the latent heat of vaporization of cooling water to cool the air sucked into the air intake of the outdoor unit of an air conditioner. As a result, the efficiency of heat exchange between the cooled intake air and the heat exchanger is improved, thereby improving the efficiency of the air conditioner. However, although this method has an effect of improving the air conditioner efficiency, it is not sufficient, and further efficiency improvement is required.

[0013] The present invention has been made by paying attention to such conventional problems, and an object of the present invention is to provide a top plate temperature drop laminated sheet for an outdoor unit of an air conditioner that can improve the efficiency of the air conditioner, can be installed inexpensively and simply without requiring specialized knowledge, technology, and tools.

[0014] Known ideas that are generally related to the top plate temperature drop of the outdoor unit of an air conditioner include measures against direct sunlight and cooling measures using water, and individual means are considered for each. Generally, although it is often advantageous in many aspects such as cost to achieve two functions with one means, there has been no idea of simultaneously achieving two functions of direct sunlight countermeasure and cooling measure using water with only one means.

Means for Solving the Problems

[0015] In order to lower the top plate temperature of the outdoor unit of the air conditioner, if we try to simultaneously perform both the function of blocking sunlight, which is one of the main sources of heat entering the top plate, and the function of actively releasing the heat of the top plate by using the latent heat of vaporization of water with one means, the following trade-off occurs. To block sunlight, a thick shield without holes or the like through which light can leak is required. For example, there is the cover described in Non-Patent Document 1. On the other hand, to lower the top plate temperature by latent heat of vaporization, irregularities or holes for ensuring the total evaporation surface area of water for promoting the vaporization phenomenon and proximity between the surface where the vaporization phenomenon mainly occurs and the top plate surface are required from the heat conduction surface. That is, these two are in a trade-off relationship.

[0016] The top plate temperature drop laminated sheet for an air conditioner outdoor unit of the present invention is a sheet formed by stacking a plurality of porous sheets, wherein the number of porous sheets is two or more, the thickness of the laminated sheet is 6 mm or less, and it suppresses the solar energy flowing into the top plate of the air conditioner outdoor unit and simultaneously overcomes the trade-off that occurs when trying to discharge the heat from the top plate of the air conditioner outdoor unit by the latent heat of vaporization of water with one means.

Effects of the Invention

[0017] The top plate temperature drop laminated sheet for an air conditioner outdoor unit of the present invention can lower the temperature of the top plate of the air conditioner outdoor unit in the hot season with the same ease as watering a flower pot in the morning, with a light economic burden. It can lower the temperature by 10 °C or more compared to the top plate temperature of the air conditioner outdoor unit under direct sunlight without any countermeasures, and by 2 °C or more compared to the top plate temperature of the air conditioner outdoor unit in the shade, and can improve the air conditioner efficiency.

[0018] In addition, it gives the possibility of solving the problem that the cooling effect of the air conditioner has not been good before or has become poor due to intense heat in the hot season, without incurring a large cost while keeping the existing air conditioner.

[0019] Furthermore, the top plate temperature drop laminated sheet for an air conditioner outdoor unit of the present invention is a countermeasure that exhibits the most effect under the most severe weather conditions such as midsummer, midday, and intense heat, and can reduce the load on the air conditioner outdoor unit in the hot season. Due to its simplicity, it can be widely popularized in society and can be used to cut the peak of the most severe electricity demand in summer.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0021] Hereinafter, the present invention will be described in detail. The top plate temperature drop laminated sheet for an air conditioner outdoor unit of the present invention is a sheet formed by stacking a plurality of porous sheets. Since the sheets used are porous, a single sheet allows much sunlight to pass through. However, even with porous sheets, by stacking a small number of them, the characteristic of having sufficient light-shielding properties against sunlight is utilized. Also, because a small number of porous sheets are stacked, the characteristics of having a large surface area necessary for water vaporization and good diffusibility of water in the planar direction are utilized. As the porous sheet, any sheet made of a water-resistant and water-absorbent fabric can be used without problems. Specifically, common white gauze, non-woven fabric, etc. can be mentioned. In order to maximize the heat of vaporization, a porous sheet made of a material with water absorption and quick-drying properties and heat conductivity has a great effect on the present invention. The arrangement of the pores in the porous sheet is regular or random. Also, the number of sheets constituting the laminated sheet varies depending on the type and thickness of the sheet, but it is necessary to be 2 or more from the viewpoints of light-shielding properties and water retention properties, preferably 4 to 24 sheets, and more preferably 6 to 18 sheets.

[0022] The present invention utilizes the phenomenon of water vaporization. An air conditioner outdoor unit is usually installed in a place exposed to the natural environment, and since the air conditioner outdoor unit itself generates wind, it takes advantage of the fact that it works favorably for the vaporization of water from the laminated sheet. The thickness of the laminated sheet needs to be 6 mm or less from the point that the surface of the laminated sheet where water vaporization mainly occurs is close to the top plate of the air conditioner outdoor unit, making it easier for the heat of vaporization to be transmitted to the top plate of the air conditioner outdoor unit. Preferably, it is 5 mm or less, and more preferably 4 mm or less.

[0023] Regarding the number of laminated sheets and the thickness of the top plate temperature drop laminated sheet for the outdoor unit of the air conditioner of the present invention, they have been described above respectively. However, the most important feature of the present invention is that by simply stacking a small number of porous sheets, a high light-shielding property against sunlight can be obtained. The laminated sheet formed by stacking several porous sheets can ensure a large total surface area necessary for promoting the evaporation of water, has good diffusibility of water in the planar direction, and has a thickness such that the effect of the heat of vaporization can sufficiently reach the top plate of the outdoor unit of the air conditioner.

[0024] In order to improve the air conditioner efficiency, the laminated sheet for the top plate temperature drop of the outdoor unit of the air conditioner in the present invention needs to maintain a state of being wet with water on the top plate of the outdoor unit of the air conditioner. As a method for maintaining this state, there is no particular restriction, and known simple methods can be used.

[0025] For example, those using capillary action, those using the principle of siphon, a combination of a solar cell and a small pump, etc. can be mentioned. The use of capillary action or siphon is a simple and inexpensive method for replenishing water. The combination of a solar cell and a small pump can be said to be a reasonable method because the power generation amount of the solar cell increases when the vaporization amount is large. However, it also has the disadvantage of not functioning at night. As a specific example using capillary action, products for watering potted plants while away are sold at home centers and the like, and these can also be arranged and used.

[0026] The laminated sheet of the present invention is installed on the outdoor unit of the air conditioner exposed to the normal natural environment during the hot season, and installation stability and ease of attachment and detachment during that period are required. As a method for satisfying this requirement, a method of fixing the laminated sheet of the present invention to the outdoor unit of the air conditioner with a magnet, a weight, a rubber band, etc. can be mentioned. Usually, the magnet adheres to the top plate of the outdoor unit of the air conditioner, and the neodymium magnet is powerful and can be used in a small area without impairing the effect of the present invention, which is useful.

[0027] In order for the laminated sheet of the present invention to exhibit 100% of its effect, it is desirable to cover 100% of the entire surface of the top plate. However, due to the installation environment of the outdoor unit of the air conditioner and the structure of the top plate of the outdoor unit of the air conditioner, when it is difficult to cover the entire surface, although the effect will be reduced, it is desirable to cover as large an area as possible.

[0028] Subsequently, an embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG. 3 is a side view of an outdoor unit of an air conditioner showing a state in which a laminated sheet for lowering the temperature of the top plate of the outdoor unit of the air conditioner is installed on the top plate of the outdoor unit of the air conditioner. The laminated sheet 1 for lowering the temperature of the top plate of the outdoor unit of the air conditioner is installed on the top plate 3 of the outdoor unit 2 of the air conditioner so as to cover the entire surface of the top plate. It is fixed to the top plate by magnets 4 attached to the four corners of the laminated sheet. Before the air conditioner operates, usually in the morning when a day begins, the laminated sheet 1 for lowering the temperature of the top plate of the outdoor unit of the air conditioner is thoroughly wetted with water.

[0029] FIG. 4 is a side view showing a state in which a water supply device including a bucket for water replenishment and a water supply pipe utilizing capillary action with holes is installed on an outdoor unit of an air conditioner on which a laminated sheet for lowering the temperature of the top plate of the outdoor unit of the air conditioner is installed. In the morning, wet the laminated sheet 1 for lowering the temperature of the top plate of the outdoor unit of the air conditioner in the same way as watering a flower pot, and fill two 2L buckets 7 with water. After that, water is replenished to the laminated sheet by capillary action without doing anything else, and the state where the top plate temperature has dropped is maintained throughout the day.

Example

[0030] Hereinafter, the present invention will be described in more detail based on examples and comparative examples. However, the present invention is not limited to these as long as it does not exceed the gist thereof.

[0031] Example 1 Commercially available cotton gauze was cut into a size of 27 cm × 76 cm, and 10 pieces of the gauze cut into the same size were stacked to produce a laminated sheet. The thickness of the laminated sheet was 2 mm. Next, 11 mm square bags were attached to the four corners of the laminated sheet, and circular magnets with a diameter of 7 mm were placed in the bags. The laminated sheet with magnets attached to the four corners was placed on the top plate of the outdoor unit of the air conditioner under direct sunlight and fixed with the top plate and the magnets. Subsequently, a hole with a diameter of 5 mm was drilled at one place in the center of the length direction of a commercially available PVC tube with an inner diameter of 10 mm and a length of 1.2 m, and then a commercially available hemp string with a length of 2 m was passed through it to produce a water supply pipe. Three of the produced water supply pipes were used and installed so that the positions of the three holes were substantially the same in the longitudinal direction of the top plate so that water replenishment would cover the entire top plate surface, and the water absorption pipe was fixed to the outdoor unit of the air conditioner with a string. Furthermore, two 2 L buckets for water were prepared on the left and right of the outdoor unit of the air conditioner, the buckets were placed on a stand to promote water replenishment, and the height of the buckets was set to the level of the top plate. The amount of water was set to 4 L to cover the evaporation amount of water for one day. The measurement day was August, the weather was sunny, almost windless, and water supply to the laminated sheet started at 9:00 am. Since the temperature of the top plate of the outdoor unit of the air conditioner became constant 30 minutes after the start of water supply, the temperature of the top plate of the outdoor unit of the air conditioner was measured at 10:00 am, one hour later, and the result was 33.8°C. The temperature of the top plate of the outdoor unit of the air conditioner when using the laminated sheet decreased by 22°C compared to the temperature of the top plate of the outdoor unit of the air conditioner measured without using the laminated sheet shown in Comparative Example 1 below.

[0032] Comparative Example 1 When the temperature of the top plate of the outdoor unit of the air conditioner used in Example 1 was measured without using the laminated sheet used in Example 1, it was 55.8°C.

[0033] Comparative Example 1 Except for changing the number of laminated layers of the cotton gauze used in Example 1 to only 1 layer, after installing the water supply device and the sheet on the air conditioner outdoor unit in the same manner as in Example 1, when the temperature of the sheet attached to the top plate was measured, it was 55.3 °C. The thickness of the single layer of gauze used was 0.2 mm. At the same time, the temperature of the top plate of the target air conditioner outdoor unit measured without using the laminated sheet was 56 °C, and the temperature drop of the top plate of the air conditioner outdoor unit when using 1 layer of the gauze was 0.7 °C.

[0034] Examples 2 to 12 Except for changing the number of laminated layers of the cotton gauze used in Example 1 to the number shown in Table 1, after installing the water supply device and the sheet on the air conditioner outdoor unit in the same manner as in Example 1, water was supplied, and the temperature of the top plate was measured 1 hour later. Table 1 shows the thickness of the laminated sheet used, the temperature of the top plate of the measurement result, the temperature of the top plate of the target air conditioner outdoor unit, and the temperature drop when using the laminated sheet.

[0035] Example 13 The test was carried out in the same manner as in Example 1 except that the installation location of the air conditioner outdoor unit was in the shade. When the temperature of the top plate of the air conditioner outdoor unit was measured, it was 33.9 °C. The temperature of the top plate of the air conditioner outdoor unit when using the laminated sheet decreased by 5.5 °C compared to the temperature of the top plate of the air conditioner outdoor unit measured without using the laminated sheet shown in Comparative Example 2 below. Even when the air conditioner outdoor unit is installed in the shade, it can be seen that the top plate dropping laminated sheet for the air conditioner outdoor unit of the present invention exhibits an effect.

[0036] Comparative Example 2 The temperature of the top plate of the air conditioner outdoor unit was measured in the same manner as in Comparative Example 1 except that the installation location of the air conditioner outdoor unit was in the shade, and it was 39.4 °C.

[0037] Comparative Example 2 Except for changing the number of laminated layers of cotton gauze used in Example 13 to only one layer, a water supply device and a sheet were installed on the outdoor unit of the air conditioner in exactly the same manner as in Example 13, and then water was supplied. After one hour, the temperature of the top plate was measured and found to be 37.5°C. At the same time, the temperature of the top plate of the target outdoor unit of the air conditioner measured without using the laminated sheet was 37.8°C, and the temperature drop of the top plate of the outdoor unit of the air conditioner when using one layer of the gauze was 0.3°C.

[0038] Examples 14 to 25 Except for changing the number of laminated layers of cotton gauze used in Example 13 to the number shown in Table 2, a water supply device and a sheet were installed on the outdoor unit of the air conditioner in exactly the same manner as in Example 13, and then water was supplied. After one hour, the temperature of the top plate was measured. The thickness of the laminated sheet used, the measured temperature of the top plate, the temperature of the top plate of the target outdoor unit of the air conditioner, and the temperature drop when using the laminated sheet are shown in Table 2.

[0039]

Table 1

Table 2

Explanation of Signs

[0040] 1 Temperature drop laminated sheet for the top plate of the outdoor unit of the air conditioner 2 Outdoor unit of the air conditioner 3 Top plate of the outdoor unit of the air conditioner 4 Magnet 5 Water supply pipe using capillary phenomenon with one hole in the middle 6 Hemp string 7 Bucket for water 8 Stand for the bucket for water

Claims

【Claim 1】 A sheet formed by stacking multiple porous sheets (hereinafter referred to as a laminated sheet), wherein the number of porous sheets is two or more and the thickness of the laminated sheet is 6 mm or less. It is a top plate temperature drop laminated sheet for an air conditioner outdoor unit, which overcomes the trade-off that occurs when trying to simultaneously suppress the solar energy flowing into the top plate of the air conditioner outdoor unit and the heat outflow from the top plate of the air conditioner outdoor unit by the latent heat of vaporization of water with one means. A top plate temperature drop laminated sheet for an air conditioner outdoor unit, characterized by this.

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