JPH0741357U - Solar water heater - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a solar water heater that can effectively concentrate sunlight incident from all directions on a metal conduit and has a small heat loss. A metal water pipe 20 is provided on the reflecting surface side of a reflecting plate 10 at both axial ends thereof to communicate with a cold water tank 22 and a hot water tank 23, and the reflecting surface of the reflecting plate has an arc-shaped cross section. The center of each virtual circle that is configured in a corrugated shape and that includes each corrugated part is located near the intersection of the line drawn from the center of the metal conduit in the direction parallel to the reflector and the pipe wall of the metal conduit. ,
In addition, the metal water conduit is provided in a space hermetically held in a vacuum state.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar water heater, and more particularly to a solar water heater having a corrugated reflector and a heat-receiving metal conduit arranged in a vacuum space above the corrugated reflector at a predetermined position.

[0002]

[Prior art]

 Conventionally, as a solar water heater of this type, as shown in FIG. 5, a heat collecting plate 50 integrated with the metal water guide tube 40 is provided on the light receiving surface side of the metal water guide tube 40, and the opposite light receiving surface side of the metal water guide tube 40 is provided. In some cases, a heat insulating material 60 covered with a tin foil 70 is provided in the housing, and these components are housed in a housing 80.

[0003]

[Problems to be solved by the device]

 However, in the conventional case, since the metal conduit 40 is usually surrounded by air, the heat concentrated by the heat collecting plate 50 is inevitably lost by conduction, convection, radiation or the like. As a result, the heat collection efficiency is not high. It is understood that this condition becomes more significant as the set water temperature increases. For example, as shown in FIG. 6, when the water temperature of the derived water is set to 29 °, the efficiency is about 65%, while the water temperature of the derived water is set to 70 ° C. or higher. The efficiency drops to about 30%. Therefore, there is a problem that the heat source cannot be used with high efficiency in practice.

The heat insulating material 60 has a large volume and a large weight, which is disadvantageous in terms of manufacture or transportation.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a solar water heater capable of effectively concentrating solar light incident from any direction on a metal water pipe and reducing heat loss. To aim.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention is provided with a metal water pipe having axial ends on both sides of the reflecting surface, which communicate with a cold water tank and a hot water tank, respectively. The reflecting surface is configured in a corrugated shape with an arcuate cross section, and the center of each imaginary circle including each corrugated portion is a line drawn from the center of the metal conduit in a direction parallel to the reflector and the metal conduit. It is characterized in that it is located near the intersection with the pipe wall and is provided in a space hermetically held in a vacuum state.

[0007]

[Action]

 With the above configuration, sunlight incident on the reflector from all directions can be correctly concentrated on the metal conduit by the corrugated portion, and since air is not surrounded by the metal conduit, conduction, No heat loss due to convection.

[0008]

【Example】

 Hereinafter, preferred embodiments of the present invention will be described in detail.

As shown in FIGS. 1 and 2, the solar water heater of the present embodiment has a reflector 10 made of plastic. The reflecting surface of the reflecting plate 10 is formed in a waveform with an arcuate cross section, and a plurality of support rods 11 are provided upright on the reflecting surface side at predetermined intervals. A top plate 30 made of transparent glass or the like is fixed above the support rods 11, and a plurality of metal water conduits 20 are provided in parallel in the space between the top plate 30 and the reflection plate 10. Both ends of each metal water conduit 20 are connected to a cold water tank 22 and a hot water tank 23, respectively. The metal conduit 20 is held in the space between a cold water tank 22 and a hot water tank 23 in a erected state.

In each corrugated portion of the corrugated reflector 10, the center of an imaginary circle that includes the corrugated portion is such that the intersection of the horizontal diameter line of the metal conduit 20 and the wall of the metal conduit 20 in FIG. Since the sunlight incident from all directions can be correctly concentrated on the metal water conduit 20 by each of the corrugated portions, the heat absorption period and the heat collection efficiency can be increased. It is possible to Silver is vapor-deposited on the corrugated surface of the reflection plate 10, and black chrome plating is applied to the surface of the obstruction guide tube 20 to increase heat collection efficiency.

Further, the four circumferences of the space between the metal water conduit 20 and the reflector 10 are sealed. For this sealing, as shown in FIG. 3, an end supporting portion of the metal conduit 20 is covered with a heat insulating material such as silicone and ceramic 24. In addition, an air vent hole 12 is provided at a predetermined portion of the reflection plate 10, and the air in the space is evacuated using the air vent hole 12 and then sealed by silicone or the like. The space can be kept vacuum. By being placed in a vacuum, there is not much heat loss due to conduction or convection.

With such an arrangement, the cold water that has entered from the cold water tank 22 is introduced into the hot water tank 23 after being effectively warmed by passing through the metal water conduit 20.

FIG. 4 shows experimental data according to the present invention conducted in Taichung, Taiwan in February and July. The 16 solar water heaters of the present invention were divided into 8 sets in 2 rows, and the effective heat receiving area was set to 5.92 m ² .

[0014]

[Outer 1]

[0015]

[Outside 2]

From the above experimental data, according to the present embodiment, even if the hot water temperature is set higher than the hot water temperature of the conventional solar water heater, the heat collection efficiency thereof is significantly higher than that of the conventional one. I can confirm.

[0017]

[Effect of device]

 As described above, the present invention having the above-mentioned configuration can effectively concentrate sunlight incident from all directions on the metal water conduit by the corrugated reflector, and the heat collection efficiency is very high. Further, since the circumference of the metal water conduit is kept in a vacuum state, there is little heat loss due to convection and conduction, and a solar water heater with a small heat loss can be provided.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing a part of a preferred embodiment of the solar water heater of the present invention.

FIG. 2 is a sectional view showing the embodiment in another direction.

FIG. 3 is a partial cross-sectional view showing the connection of the water conduit of the embodiment.

FIG. 4 is a curve diagram showing the relationship between the derived water temperature and the heat collection efficiency in the solar water heater of the present invention when there is merely heat loss due to radiation.

FIG. 5 is a cross-sectional view showing a conventional solar water heater.

FIG. 6 is a curve diagram showing the relationship between the derived water temperature and the heat collection efficiency when there is a heat loss due to radiation, convection, conduction, etc. in the conventional solar water heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Reflector 11 Support rod 12 Air vent 20 Metal conduit 22 Cold water tank 23 Hot water tank 24 Insulation material 30 Top plate 40 Metal conduit 50 Heat collecting plate 60 Insulating material 70 Tin foil 80 Housing

Claims (1)

[Scope of utility model registration request] 1. A reflector is provided with metal water pipes whose axial ends are respectively connected to a cold water tank and a hot water tank, and the reflector has a corrugated cross section. The center of each imaginary circle including each corrugated portion is near the intersection of the line drawn from the center of the metal conduit in a direction parallel to the reflector and the wall of the metal conduit. A solar water heater, which is located and is provided in a space in which the metal conduit is hermetically held in a vacuum state.