US20100126500A1

US20100126500A1 - Heat collector

Info

Publication number: US20100126500A1
Application number: US12/594,398
Authority: US
Inventors: Ik Ro Ahn
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-04-03
Filing date: 2008-04-01
Publication date: 2010-05-27
Also published as: CN101680684A; WO2008120943A1; JP2010523930A; EP2156106A1; KR20080089954A; KR100926537B1

Abstract

A heat collector is disclosed. The heat collector includes a heat collecting part to receive external heat while working fluid as a heat transfer medium flows therethrough, a heat insulating part provided to surround the heat collecting part so as to decrease heat loss of the heat collecting part, and a reflecting membrane formed in the heat insulating part to reflect and concentrate incident light onto the heat collecting part. Accordingly, since the reflecting membrane is positioned around the heat collecting part, incident light can be concentrated on the heat collecting part. Since the vacuum part is provided between the heat collecting part and the heat insulating part, heat radiation from the heat collecting part due to convection and conduction is decreased. Efficiency of the overall system is enhanced.

Description

TECHNICAL FIELD

The present invention relates to a heat collecting system, and more particularly, to a heat collector capable of efficiently absorbing external heat.

BACKGROUND ART

FIG. 1 is a schematic view illustrating a general heat collecting system using a tube type heat collector. As shown in the drawing, a heat collecting system 2 includes a heat collector 4 to convert working fluid introduced thereinto through a water supply pipe P into working fluid of high temperature, a heat accumulator 6 to store the working fluid of high temperature, and a pump 8 to supply the working fluid to the heat accumulator 6 from the heat collector 4.
As shown in FIG. 2, the heat collector 4 includes a heat collecting part 10 through which the working fluid flows, and a heat insulating part 12 which surrounds the heat collecting part 10 and is filled with a heat insulating gas. The working fluid serves to transfer a thermal energy absorbed from incident light to the heat accumulator 6. Water is commonly used as the working fluid, however the working fluid is not limited to water. In order to prevent the working fluid from being frozen in winter, an antifreezing solution or a mixture of an antifreezing solution and water by a predetermined ratio may be used as the working fluid.
The heat accumulator 6 serves to store the thermal energy contained in the working fluid, and is designed so as to minimize heat loss to the outside.
The operation of the above-described conventional heat collecting system will now be explained.
The working fluid, which serves as a heat transfer medium, is introduced into the heat collector 4, and the working fluid in the heat collector absorbs solar heat and is converted into working fluid of high temperature. After such a heat collecting process, the working fluid of high temperature is discharged from the heat collector 4, and then flows into the heat accumulator 6 by the pump 8. The thermal energy stored in the heat accumulator 6 is used for heating or warm water as needed.

DISCLOSURE OF INVENTION

Technical Problem

However, the conventional heat collector has a problem such that it cannot effectively collect heat. Such a problem is resulted from that the heat collecting structure is not a structure effective for heat collection.
Also, the heat insulating part of the heat collector does not have a structure sufficient for effective heat insulation for the heat collecting part.
An object of the present invention is to provide a heat collector capable of more effectively collecting heat.

Technical Solution

The objects of the present invention can be achieved by providing a heat collector comprising: a heat collecting part to receive external heat while working fluid as a heat transfer medium flows through the heat collecting part; a heat insulating part provided to surround the heat collecting part so as to decrease heat loss of the heat collecting part; and a reflecting membrane formed in the heat insulating part so as to reflect and concentrate incident light onto the heat collecting part.
The reflecting membrane may be formed to be rounded, centering on the heat collecting part.
The reflecting membrane may be made of a material capable of reflecting the incident light to the heat collecting part so that the incident light is concentrated on the heat collecting part.
The reflecting membrane may be made of a flexible material.
The reflecting membrane may divide the heat insulating part into two spaces, and the two spaces may have pressures different from each other.
In another aspect of the present invention, provided herein is a heat collector comprising: a heat collecting part to receive external heat while working fluid as a heat transfer medium flows through the heat collecting part; and a heat insulating part filled with a heat insulating gas, the heat insulating part being defined by a heat insulating membrane provided to surround the heat collecting part, and the heat insulating membrane including an inner surface having a reflecting function so as to reflect and concentrate incident light onto the heat collecting part.
In another aspect of the present invention, provided herein is a heat collector comprising: a heat collecting part to receive external heat while working fluid as a heat transfer medium flows through the heat collecting part; a heat insulating part filled with a heat insulating gas, the heat insulating part surrounding the heat collecting part to decrease heat loss of the heat collecting part; and a vacuum part provided between the heat insulating part and the heat collecting part to wrap the heat collecting part, the vacuum part being formed so that a negative pressure is generated therein.
The vacuum part may be sectioned into a plurality of spaces. At this time, a plurality of partitions may be used to divide the vacuum part.
The divided spaces may have the substantially same pressure.
The partitions may be formed with through-holes.
The heat collector may further comprise an air path to allow external air to be introduced or discharged into/from the vacuum part.
The vacuum part and the heat insulating part may have pressures different from each other.
In a further aspect of the present invention, provided herein is a heat collector comprising: a heat collecting part to receive external heat while working fluid as a heat transfer medium flows through the heat collecting part; a heat insulating part provided to surround the heat collecting part so as to decrease heat loss of the heat collecting part; a vacuum part provided between the heat insulating part and the heat collecting part to wrap the heat collecting part, the vacuum part being formed so that a negative pressure is generated therein; and a reflecting membrane formed in either the vacuum part or the heat insulating part to reflect and concentrate incident light onto the heat collecting part.
In yet another aspect of the present invention, provided herein is a heat collector comprising: a heat collecting part to receive external heat while working fluid as a heat transfer medium flows through the heat collecting part; a heat insulating part defined by a heat insulating membrane provided to surround the heat collecting part so as to decrease heat loss of the heat collecting part; and a vacuum part defined by a vacuum membrane provided between the heat insulating part and the heat collecting part to wrap the heat collecting part, the vacuum part being formed so that a negative pressure is generated therein. Either the heat insulating membrane or the vacuum membrane includes a surface which opposes the heat collecting part and has a reflecting function within a predetermined region thereof.
According to the heat collector of the present invention as constituted above, since the reflecting membrane is provided around the heat collecting part, incident light can be concentrated on the heat collecting part. Further, if the vacuum part is provided between the heat collecting part and the heat insulating part, heat radiation and loss from the heat collecting part can be decreased.

ADVANTAGEOUS EFFECTS

The heat collector according to the present invention as explained above has the following effects.
Since the reflecting membrane is positioned around the heat collecting part of the heat collector, the incident light can be concentrated on the heat collecting part. Accordingly, the higher heat collecting effect can be obtained.
Further, since the vacuum part is provided between the heat collecting part and the heat insulating part, the heat radiation from the heat collecting part to the outside can be decreased.

MODE FOR THE INVENTION

Hereinafter, a heat collector according to a first embodiment of the present invention will be described with reference to FIG. 3.
As shown in FIG. 3, a heat collector 20 according to the present invention includes a heat collecting part 23 which receives external heat while working fluid as a heat transfer medium flows therethrough, a heat insulating part 25 which is an inner space of a heat insulating membrane 24 mounted to surround the heat collecting part 23, the heat insulating part 25 being filled with a heat insulating gas and serving to decrease heat loss of the heat collecting part 23, and a reflecting membrane 26 which is formed in the heat insulating part 25 in order to reflect and concentrate incident light onto the heat collecting part 23.
The heat insulating part 25 serves to decrease radiation of a thermal energy of the working fluid located in the heat collecting part 23 to the outside, and there is no limitation in the kind of heat insulating gas filled in the heat insulating part 25. However, it is preferred that air, which is economical and easily available, is used as the heat insulating gas.
The heat collecting part 23 serves to receive external heat, and may be defined by a heat collecting membrane 22. The heat insulating part 25 may be defined by the heat insulating membrane 24 in which the heat insulating gas can be filled. Solar light may be used as the incident light.
The heat insulating part 25 may be sectioned into a plurality of spaces by partitions 25 a. FIG. 3 illustrates the heat collector having the three partitions 25 a provided in the heat insulating part 25. The partitions 25 a serve to connect the heat collecting membrane 22 with the heat insulating membrane 24, thereby preventing the heat collecting part 23 from severely sagging under the weight of the working fluid in the heat collecting part 23 in the gravity direction.
The partitions 25 a are formed with a plurality of through-holes (not shown), so that two spaces of the heat insulating part 25, which are divided by each of the partitions 25 a, can have the same inner pressure as each other.
Preferably, the heat insulating membrane 24 and the partitions 25 a are made of a transparent material so that the external light can pass therethrough. Also preferably, the heat collecting membrane 22 is made of a black material so as to increase light absorptiveness.
Further, the heat collecting membrane 22, the heat insulating membrane 24 and the partitions 25 a may be made of a flexible material. In other words, the heat collecting membrane 22, the heat insulating membrane 24 and the partitions 25 a may be made of a resin material, e.g., vinyl resin. When the flexible material such as vinyl resin is used, the heat collector 20 can be swollen by filling the heat insulating gas into the gas insulating part 25 sufficiently to make the pressure in the heat insulating part 25 larger than the atmospheric pressure, and the working fluid in the heat collecting part 23 can have an adequate pressure. Accordingly, the sectional shape adequate for heat collection can be realized as shown in FIG. 3.
The resin has merits of a low price and easy modification in various shapes. The heat collector can be formed in a shape adequate to receive solar light. The heat collector 20 can be installed in a broad place, such as a field, a farm, etc. Depending on the change of shape or installing position of the heat collector, even when the density of incident solar light is low, an excellent heat collecting effect can be obtained.
The heat collector 20 further includes the reflecting membrane 26 so that the light having passed through the heat insulating membrane 24 and the partitions 25 a can be reflected to the heat collecting part 23. The reflecting membrane 26 is provided in the heat insulating part 25. The reflecting membrane reflects the incident light so that more incident light can enter the heat collecting part 23. By virtue of the reflecting membrane, the better heat collecting effect can be obtained.
Also, as shown in FIG. 3, the reflecting membrane 26 may be formed in a thin film, and may be formed to be rounded, centering on the heat collecting part 23, in an opposite portion to a portion receiving the incident light. The reflecting membrane 26 rounded centering on the heat collecting part 23 concentrates the light reflected therefrom onto the heat collecting part 23.
The reflecting membrane 26 may be made of a reflective material so as to reflect the light. For example, a material such as mercury may be coated on one surface of the reflecting membrane 26 so that minor reflection can be achieved. The overall reflecting membrane 26 may be made of a reflective material, or only a portion of the reflecting membrane 26 may be made of a reflective material.
The reflecting membrane 26 may also be made of a flexible material. For example, the reflecting membrane is made of resin, to thereby improve workability. When the resin is used for the reflecting membrane, the reflecting surface may be plated with metal.
Also, as shown in FIG. 3, the heat collector may be constituted such that a pressure applied to the incident light receiving space of the heat insulating part 25 defined by the reflecting membrane 26 is different from a pressure applied to the space opposite to the incident light receiving space. For example, if the pressure of the incident light receiving space is set to be larger than the pressure of the opposite space, the reflecting membrane 26 is always kept in the expanded state as shown in the drawing, so as not to be contacted with the heat collecting membrane 22.
Moreover, since the reflecting membrane 26 is always kept in the shape as shown in FIG. 3, the light can be reflected and concentrated onto the heat collecting part 23.
In the above-described embodiment, the reflecting membrane 26 is separately provided. However, the reflecting membrane 26 may be eliminated, and the inner surface of the heat insulating membrane 24 may be formed to have a reflecting function so as to reflect the light incident near the heat collecting part 23 and concentrate the light on the heat collecting part 23. The inner surface of the heat insulating membrane 24 may be designed to wholly or partially have the reflecting function as needed.
Hereinafter, the operation of the heat collector according to the first embodiment of the present invention will be explained. The working fluid flows along a path in the heat collecting membrane 22. At this time, the external incident light transmits the heat insulating membrane 24. A portion of the incident light is introduced into the heat collecting part 23, and the remaining portion transmits the partitions 25 a.
The light having transmitted the partitions 25 a reaches the reflecting membrane 26. Then, the light is reflected from the reflecting membrane 26, and is introduced into the heat collecting part 23. At this time, since the reflecting membrane 26 is rounded centering on the heat collecting part 23, the light reflected from the reflecting membrane 26 can be more concentrated on the heat collecting part 23.
Next, a heat collector according to a second embodiment of the present invention will be described with reference to FIG. 4.
As shown in FIG. 4, a heat collector 30 according to the present invention includes a heat collecting part 33 which receives external heat while working fluid as a heat transfer medium flows therethrough, a heat insulating part 35 which is filled with a heat insulating gas and surrounds the heat collecting part 33 to decrease heat loss of the heat collecting part 33, and a vacuum part 37 which is provided between the heat insulating part 35 and the heat collecting part 33 to wrap the heat collecting part 33 and in which a negative pressure is generated.
The heat collecting part 33 and the heat insulating part 35 may be constituted similar to the first embodiment shown in FIG. 3. The point different from the first embodiment is that the vacuum part 37 is additionally provided between the heat collecting part 33 and the heat insulating part 35, which will be explained in detail hereinafter.
The vacuum part 37, as shown in FIG. 4, is formed to perfectly wrap the heat collecting part 33. A negative pressure, which is a pressure lower than the atmospheric pressure, is generated in the vacuum part.
If the vacuum part 37 has a negative pressure, heat convection and heat transfer in the vacuum part 37 are decreased, when compared to a positive pressure which is a pressure higher than the atmospheric pressure. That is, the heat in the heat collecting part 33 is blocked by the vacuum part 37, and thus heat radiation to the outside is decreased. Accordingly, since heat loss from the heat collecting part 33 is reduced by the vacuum part 37, thermal efficiency of the overall heat collector 30 is enhanced.
The vacuum part 37 may be provided with an air path (not shown), through which the interior of the vacuum part 37 communicates with the exterior. For example, the air path may be configured as a tube mounted to communicate the interior of the vacuum part 37 with the exterior.
A vacuum membrane 36 defining the vacuum part 37 is disposed at a predetermined gap from a heat collecting membrane 32 defining the heat collecting part 33. That is, the vacuum part 37 can be formed by disposing the vacuum membrane 37 at a predetermined gap from the heat collecting membrane 32, and the above-described effects can be achieved.
The vacuum part 37 may be provided with a plurality of partitions 36 a therein, in order to divide the vacuum part 37. The partitions 36 a serve to connect the heat collecting membrane 32 with the vacuum membrane 36, thereby preventing the heat collecting part 33 from severely sagging under the weight of the working fluid in the heat collecting part 33 in the gravity direction.
The air path may be provided at each of the spaces of the vacuum part 37, which are divided by the partitions 36 a. However, if the respective partitions 36 a are formed with through-holes (not shown), all of the divided spaces of the vacuum part 37 have the same pressure. In such a case, only one air path may be provided at the vacuum part 37.
A heat insulating membrane 34 is disposed at a predetermined gap from the vacuum membrane 36. That is, an air layer can be formed in the air insulating part 35 by disposing the heat insulating membrane 34 at a predetermined gap from the vacuum membrane 36, and the air layer serves as a heat insulating means. Accordingly, the heat in the heat collecting part 33 can be insulated.
The pressure in the heat insulating part 35 should be maintained over a predetermined value. More preferably, as shown in FIG. 4, the pressure in the heat insulating part 35 is set to be high enough to expand the heat insulating membrane 34 outside. By virtue of partitions 34 a connected to the expanded heat insulating membrane 34, the vacuum membrane 36 is not contacted with the heat collecting membrane 32 while keeping a predetermined gap with the heat collecting membrane 32.
In order to make the spaces divided by the partitions 34 a have the same pressure, the partitions 34 a may be formed with through-holes (not shown), similar to the partitions of the vacuum part 37.
Hereinafter, the operation of the heat collector according to the second embodiment of the present invention will be explained. The working fluid flows along a path in the heat collecting part 33. At this time, the external incident light transmits the heat insulating membrane 34 and the vacuum membrane 36, and is introduced into the heat collecting part 33.
The light introduced into the heat collecting part 33 is used to heat the working fluid in the heat collecting part 33. When the heat collecting part 33 is heated to have a temperature higher than an external temperature, the heat in the heat collecting part 33 may be radiated to the outside.
However, since the vacuum part 37 having a predetermined space is provided to wrap the heat collecting part 33, the amount of heat radiated to the outside is reduced. Further, since a negative pressure is generated in the vacuum part 37, the amount of air as a heat transfer medium is small, and thus heat conduction and heat convection do not occur much. Accordingly, the heat radiation from the heat collecting part 33 to the outside does not occur much, and as a result heat collecting efficiency is enhanced.
As shown in FIG. 5, a heat collector 40 according to a third embodiment of the present invention includes both a reflecting membrane 48 and a vacuum membrane 46.
The heat collector 40 includes a heat collecting part 43 which receives external heat while working fluid as a heat transfer medium flows therethrough, a heat insulating part 45 which surrounds the heat collecting part 43 to decrease heat loss of the heat collecting part 43, a vacuum part 47 which is provided between the heat insulating part 45 and the heat collecting part 43 to wrap the heat collecting part 43 and in which a negative pressure is generated, and a reflecting membrane 48 which is formed in either the vacuum part 47 or the heat insulating part 45 to reflect and concentrate the heat onto the heat collecting part 43.
Instead of the reflecting membrane 48, a surface of either the vacuum membrane 46 or the heat insulating membrane 44, which opposes the heat collecting part, may be formed to have a reflecting function within a predetermined region of the surface, so as to concentrate the incident light on the heat collecting part 43.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

INDUSTRIAL APPLICABILITY

The present invention relates to the heat collecting system, and more particularly, to the heat collector capable of effectively absorbing external heat. The heat collector according to the present invention has the reflecting surface. The reflecting surface reflects the incident light to the heat collecting part so that a larger amount of light is concentrated on the heat collecting part, thereby enhancing the heat collecting effect.

Claims

1. A heat collector comprising: a heat collecting part to receive external heat while working fluid as a heat transfer medium flows through the heat collecting part; a heat insulating part provided to surround the heat collecting part so as to decrease heat loss of the heat collecting part; and a reflecting membrane formed in the heat insulating part so as to reflect and concentrate incident light onto the heat collecting part.

2. The heat collector according to claim 1, wherein the reflecting membrane is formed to be rounded, centering on the heat collecting part.

3. The heat collector according to claim 1, wherein the reflecting membrane is made of a material capable of reflecting the incident light to the heat collecting part so that the incident light is concentrated on the heat collecting part.

4. The heat collector according to claim 3, wherein the reflecting membrane is made of a flexible material.

5. The heat collector according to claim 3, wherein the reflecting membrane divides the heat insulating part into two spaces, and the two spaces have pressures different from each other.

6. A heat collector comprising: a heat collecting part to receive external heat while working fluid as a heat transfer medium flows through the heat collecting part; and a heat insulating part filled with a heat insulating gas, the heat insulating part being defined by a heat insulating membrane provided to surround the heat collecting part, and the heat insulating membrane including an inner surface having a reflecting function so as to reflect and concentrate incident light onto the heat collecting part.

7. A heat collector comprising: a heat collecting part to receive external heat while working fluid as a heat transfer medium flows through the heat collecting part; a heat insulating part filled with a heat insulating gas, the heat insulating part surrounding the heat collecting part to decrease heat loss of the heat collecting part; and a vacuum part provided between the heat insulating part and the heat collecting part to wrap the heat collecting part, the vacuum part being formed so that a negative pressure is generated therein.

8. The heat collector according to claim 7, wherein the vacuum part is sectioned into spaces by a plurality of partitions.

9. The heat collector according to claim 8, wherein the spaces sectioned by the partitions have the same pressure.

10. The heat collector according to claim 8, wherein the partitions are formed with through-holes.

11. The heat collector according to claim 7, further comprising: an air path to allow external air to be introduced or discharged into/from the vacuum part.

12. The heat collector according to claim 7, wherein the vacuum part and the heat insulating part have pressures different from each other.

13. A heat collector comprising: a heat collecting part to receive external heat while working fluid as a heat transfer medium flows through the heat collecting part; a heat insulating part provided to surround the heat collecting part so as to decrease heat loss of the heat collecting part; a vacuum part provided between the heat insulating part and the heat collecting part to wrap the heat collecting part, the vacuum part being formed so that a negative pressure is generated therein; and a reflecting membrane formed in either the vacuum part or the heat insulating part to reflect and concentrate incident light onto the heat collecting part.

14. A heat collector comprising: a heat collecting part to receive external heat while working fluid as a heat transfer medium flows through the heat collecting part; a heat insulating part defined by a heat insulating membrane provided to surround the heat collecting part so as to decrease heat loss of the heat collecting part; and a vacuum part defined by a vacuum membrane provided between the heat insulating part and the heat collecting part to wrap the heat collecting part, the vacuum part being formed so that a negative pressure is generated therein, wherein either the heat insulating membrane or the vacuum membrane includes a surface which opposes the heat collecting part and has a reflecting function within a predetermined region thereof.

15. The heat collector according to claim 2, wherein the reflecting membrane is made of a material capable of reflecting the incident light to the heat collecting part so that the incident light is concentrated on the heat collecting part.

16. The heat collector according to claim 9, wherein the partitions are formed with through-holes.