FR2500917A1 - Portable solar water heater - has two way non return valve with flexible plug for water to be heated - Google Patents

Abstract

The water heater is hemispherical in shape with a hollow shell filled with water (7) to be heated. The majority of the curved area has a heat absorbant surface below which flows the heating fluid in the jacket (5). The heating fluid circulates through circuits (12,14). The container is insulated (13) below the absorbant surface underneath (5) and around the filling plug (2,4). A two-way non-return valve (15) is fitted in each heating fluid duct. The change in the sense in which the non-return valve operates is achieved by compressing the heating fluid which compresses the flexible plug in the non-return valve and causes it to sink.

Description

 The present invention relates to a heat exchanger, in particular a solar exchanger intended for camping.

In leisure activities such as camping, hot water is often needed either for showers, or for laundry or dishes. Although, in most
In some cases, the campers are equipped with stoves, it would be preferable to take advantage of the solar energy, available, to heat the water for domestic use. Indeed, campers thus have greater, even total, autonomy.

 There is thus a plastic bag which the campers fill with water and allow it to stay in the sun to heat the water. It is also possible to place a container containing water in the sun.

 However, these so-called "makeshift" solutions do not have the best efficiency, especially in low sun. The disadvantage of these solutions is that they have poorly oriented and insufficient heat-collecting surfaces and heat exchange means. In addition, the pocket or the container does not have thermal insulation means, preventing heat loss.

 This is particularly important for water storage. In fact, since the container or the bag are not thermally insulated, they very quickly lose the accumulated heat. Conversely, we cannot consider using insulated containers to try to heat the contents in the sun.

 The object of the present invention is to create a portable heat exchanger device intended for camping or for similar uses which makes it possible to heat or cool: a certain quantity of water and to store this quantity of water for a period of time. reasonable and this using a device of relatively easy manufacture, inexpensive, compatible with the requirements of its use.

 To this end, the invention relates to a device characterized in that the collection surface surrounds at least a large part of the tank, this surface being separated from the tank by a thermally insulating partition and the circuit of the heat transfer fluid is in contact with the tank. , the device comprising gripping means.

 A complete, portable device is thus obtained, with a very small footprint. As, moreover, the capture surface surrounds the tank, this provides the largest capture surface possible. This surface is particularly advantageous when, according to another characteristic of the invention, it is in the form of a spherical cap, the top of which is occupied by the gripping means. This allows a particularly effective insolation since the collecting surface is almost entirely exposed to solar radiation.

 It should be noted that this device, which is intended to function as a heat receiver when it is exposed to solar radiation as such, can also operate as a cold generator, if it is surrounded by a damp cloth; in fact, the evaporation of humidity will draw calories from the enclosure behind the collection surface. Due to the thermosyphon effect, the cold heat transfer fluid will heat up in contact with the liquid in the reservoir, that is to say will cool this liquid.

 Likewise, in night-time operation, since the collection surface is directly in contact with the heat-transfer liquid, it is thus possible to cool the liquid inside the tank to have cold liquid.

 The thermosiphon thus works in reverse; the capture surface radiates the celestial volte and gives up the calories that the heat transfer fluid draws from the liquid in the reservoir.

 As the tank is insulated, there is great flexibility of use. Indeed, it suffices to place the exchanger device in the sun for it to recover the calories and heat the liquid. Given the insulation, the tank retains its temperature even after the sun has disappeared when it has operated as a heat sensor, ie after sunrise, when during the night it has operated as a cold generator.

 As, according to another characteristic of the invention, the heat transfer fluid circuit is controlled by a non-return valve or valve making it possible to determine the direction of circulation of the heat transfer fluid, any accidental reversal of the movement of the heat transfer fluid is avoided. This makes it possible not to monitor the operation of the device, in the intermediate periods when it would be necessary to stop its operation for example after sunset or at the time of sunrise.

 According to another particularly important characteristic, the exchanger absorber device is composed of elements joined together to form the compartmentalized assembly in sectors. This partitioning is particularly important because it prevents certain parts of the device from operating simultaneously in opposite directions. Indeed, if the volume behind the collection surface was not partitioned, as a part of the surface can be exposed to the sun and the other, be in the shade, the heat transfer liquid would circulate in an opposite way and would evacuate towards the outside, at the level of the surface in the shade, part of the calories received by the surface in the sun. In addition, this embodiment in the sector makes it possible to considerably simplify the manufacture of the device when it is, for example, produced injection of synthetic material. It is indeed sufficient to have a small mold corresponding to a fraction - only of the shape of the entire device. The elementary parts thus obtained by molding can be joined by gluing, welding or the like.

 According to an interesting characteristic, the collection surface, the enclosure and the rear volume through which the heat transfer fluid forms, an envelope which receives the reservoir. Which comes into contact with the circuit of the heat transfer fluid.

 This tank has a shape complementary to that of the rear volume to promote heat exchange by contact. This allows the same jacket to be used for several successive tanks to heat several volumes of water.

The present invention will be described in more detail with the aid of embodiments shown schematically in the accompanying drawings, in which
- Figure 1 is a side view of a portable solar exchanger according to the invention.

- Figure 2 is a vertical half-section along
II-II of Figure 4 of a first embodiment of an exchanger, according to the invention.

 - Figure 3 is a vertical half-section along III-IÍ of Figure 4 of a second embodiment of an exchanger according to the invention.

 - Figure 4 is a horizontal section on IV-IV of Figures 2 and 3.

 - Figure 5 is a detail of an embodiment of a non-return valve.

 According to Figure 1, the heat exchanger device according to the invention consists of a body 1 corresponding to the collection surface, terminated at its top by a head 2 provided with handles 3 and an insulating plug 4 allowing the filling of the tank (not visible in this figure).

In its lower part, the exchanger includes a base 5.

 The device according to FIG. 1 has a form of revolution, the body of which is a spherical cap subdivided into sectors 6.

 This shape is particularly compact and corresponds to a large exchange surface. In addition, it is interesting that this volume is flattened to provide as much useful surface as possible in the sun when it operates as a heat sensor, especially in summer, the preferred camping season.

 Figures 2 and 3 show two embodiments of an exchanger according to the invention.

 According to the first embodiment (FIG. 2), the outer surface 11 of the body 1 constitutes the collection surface. This surface 11 forms an enclosure 12 for the heat transfer fluid (shown diagrammatically with the two arrows A> with an insulating wall 13. As the collection surface 11 is preferably as thin as possible, to reduce the thermal inertia, it is advantageous that the insulating partition 13 at the same time ensures the mechanical strength of the body 1. This partition 13 is integral with the bottom 5, preferably also made of an insulating material.

 The enclosure 12 communicates with tubes 14 forming a circulation loop of the heat transfer fluid. Inside the tube 14 is a non-return device 15 which will be explained later.

 The partition 13 and the bottom 5 delimit the interior volume of the exchanger forming the reservoir 7. This volume contains the liquid to be heated (or if necessary to be cooled).

 The filling of the reservoir 7 is done for example by the upper part of the head 2 after removal of the plug 4. However, other filling means can be provided. One can also consider a drain valve located in the lower part of the device and not shown in the figures.

 In the first embodiment described above, the enclosure 12 of the heat transfer fluid behind the collection surface 11 is connected to a certain number of pipes 14 for circulation of the heat transfer fluid. These pipes 14 pass through the reservoir 7 and the circulation of the heat transfer fluid is by thermosiphon.

 According to the second embodiment (Figure 3), the reservoir 7 'which contains the fluid to be heated or cooled is no longer traversed by the tubes of the heat transfer fluid.

 On the contrary, the enclosure 12 communicates with tubes or volumes 14 ', separated from the enclosure 12 by the insulating partition 13. The tubes or volumes 14' do not pass through the tank 7 'but they are only in contact with the outer surface thereof. This allows the reservoir 7 'to be produced in the form of a removable reservoir.

 In this case, the device consists of a casing formed of the elements 11, 12, 13, 14 'and of the head 2 as well as of a removable tank 7'.

It is important that, in this case, the shape of the peripheral surface 71 of the reservoir 7 'corresponds to that of the non-wall
referenced tdelimiting the conduits or the volumes 14 'to ensure good heat exchange by conduction. In addition, it is possible to have thin walls since none of them is exposed to shocks or must have a mechanical function.

 In this example, the bottom is composed of a peripheral part 5 integral with the envelope and a central part 72 belonging to the reservoir 7 '.

 According to a variant not shown, the bottom of this second embodiment is removable, the reservoir 7 'being introduced through the opening of the bottom.

 In the rear volume 14 ′, a stop valve 15 or non-return valve is provided. The embodiment in this example is slightly different from that of the stop valve 15 of the embodiment of FIG. 2.

 However, the various embodiments are interchangeable and any other means making it possible to avoid reverse circulation of the heat transfer fluid with respect to the preselected circulation, is possible.

 It is particularly advantageous for the proper functioning of the thermosyphon, that the reservoir 7, 7 'comprises at least one part above or below the respective high and low points of the heat transfer fluid circuit. In the sensor according to the invention, this is advantageously achieved in particular by the volume of the reservoir inside the head 2.

 Figure 4 is a horizontal section of Figures 2 and 3 showing a part of the collection surface 11, the enclosure 12, located behind this collection surface, the insulating partition 13, In its left part and in the middle, Figure 4 shows in section the conduits 14. In the right part, the conduits 14 are replaced by a rear volume 14 'possibly subdivided into channels or corresponding only to a part of the interior or rear surface of the insulating partition 13.

 According to FIG. 4, the entire device is subdivided into six independently achievable sectors. Each sector thus comprises a part of - the collection surface 11, of the enclosure 12 and of the insulating partition 13.

 According to this embodiment, each sector comprises a duct 14 or part of the return volume 141.

The sectors are distinct from each other. The parts such as the collection surface 11, the enclosure 12 and the insulating partition 13 are limited by a partition 8. The other parts and in particular the fraction of the reservoir or interior volume 7 or 7 ′ are occupied by open partitions 81. The corresponding partitions of two sectors being adjacent.

This subdivision of the device into sectors is interesting} because it considerably simplifies manufacturing and reduces the cost of the mold when this manufacturing is done by injection.

 It will suffice, in fact, to mold six identical elements using the same mold and then to assemble them by gluing, welding or other suitable connecting means, depending on the material used.

 In the case of the second embodiment (FIG. 3 on the right, FIG. 4), the partitions cannot exist at the level of the reservoir 7 ′ since the entire interior volume of the device is occupied by a separate reservoir 7 ′.

 As a variant, however, this reservoir can also be constituted by the combination of several reservoirs.

 In the various embodiments described above; the heat transfer fluid circuit includes a non-return valve to prevent reverse operation.

Indeed, when the heat exchanger is exposed for example to the sun, but a part of the collection surface is in the shade, the heat transfer fluid circulating in this part, could tend to circulate in the opposite direction, c '' ie to pass heated heat transfer fluid into contact with the liquid inside the tank 7, 7 'to heat the collection surface 11 in the shade and radiate outwards the heat supplied by the fluid coolant, which would reduce the yield. To avoid such antagonistic operation, it is advantageous to provide a non-return valve
When the solar exchanger is only designed to operate as a heat receiver, a one-way non-return valve is sufficient; on the other hand, when the device has to be reversible, i.e. allow selective operation, either as a receiver heat, either as a heat generator (to cool a liquid), the stop valves must be able to operate in two directions, according to the choice which will be made
FIG. 5 shows the detail of an embodiment of a non-return valve 15. According to FIG. 5, the valve consists of two seats 151, 152 provided in line 14.

Between these stops is a deformable float 153, at least part of the wall 154 of which is deformable. This float is empty or contains a gas so that it can deform as a function of the pressure of the heat transfer fluid acting on its walls.

 For a certain volume or a certain state, this float has a density equal to that of the heat transfer fluid. If the float is compressed by deforming for example the wall 154 to reduce the volume of the float, the density of the float will increase and it will tend to apply against the lower seat 152. On the other hand, if the pressure of so as to increase the volume of the float 153, its density will exceed that of the heat-transfer fluid and the float will tend to lift to apply against the upper seat 151.

 To exert the appropriate pressure on the heat transfer fluid, there is provided a piston 9 opening into the heat transfer fluid circuit. This piston can be a screw or a ratchet rod.

 Depending on whether the piston is more or less penetrated into the heat transfer fluid circuit, the heat transfer fluid is compressed and the deformation described above is caused.

 Such a piston 9 is necessarily associated with each heat transfer fluid circuit. To simplify the order, a general order can be provided, such as a crown acting on all of the pistons.

 Finally, the device according to the invention can be completed by a transparent outer envelope in the form of a skirt to create a greenhouse effect for operation as a heat sensor. This envelope can be a removable skirt.

 For operation as a cold generator, it is possible to have a skirt impregnated with water, the evaporation of which creates cold.

Claims (7)

 10) Portable heat exchanger device, in particular solar exchanger intended for camping, exchanger comprising a container (7) and a collection surface (11) as well as a circuit (12, 14) for circulation of the heat transfer fluid between the surface of collection and the tank (7, 7 '), portable device characterized in that the collection surface (11) surrounds at least a large part of the tank (7, 7') by a thermally insulating partition (13) and the circuit ( 12, 14) of the heat transfer fluid is in contact with the reservoir (7, 7 '), the device comprising gripping means (3).  20) Device according to claim 1, characterized in that its collection surface (11) as well as the circuit (12, 14, 14 ') of the heat transfer fluid are divided into independent elements (6) whose meeting constitutes the surface of capture and circuit of the heat transfer fluid.  30) Device according to claim 1, characterized in that, by the collection surface (11), the enclosure (12) as well as the rear volume (14 ') traversed by the heat transfer fluid form an envelope receiving the reservoir (7 ') coming into contact with the heat transfer fluid circuit (14').  40) Device according to claim 1, characterized in that the circuit of the heat transfer fluid consists of an enclosure (12) located behind the collection surface and by at least one tube (14) inside the tank (7) directly in contact with the tank liquid.  50) Device according to claim 1, characterized in that the heat transfer fluid circuit is provided with a non-return valve (15) making it possible to determine the direction of circulation of the heat transfer fluid and the operation of the device (heat receptor or emitter ).  60) Device according to claim 5, characterized in that the non-return valve is a two-position valve for choosing the direction of circulation of the heat transfer fluid.  70) Device according to claim 1, characterized in that the capture surface has a shape of a spherical cap whose top is occupied by the cap (4) of the reservoir (7, 7 ') and the gripping means (3).