WO2010008329A1

WO2010008329A1 - An energy cell

Info

Publication number: WO2010008329A1
Application number: PCT/SE2008/050874
Authority: WO
Inventors: Bengt ÖSTLUND
Original assignee: Exencotech Ab
Priority date: 2008-07-16
Filing date: 2008-07-16
Publication date: 2010-01-21

Abstract

The present invention relates to an energy cell (10) operable to generate mechanical energy when a phase change material (PCM) changes from solid phase to liquid phase. The energy cell (10) comprises a housing means (12) holding the phase change material (PCM). The energy eel! (10) also comprises an insulating means (14) arranged between the housing means (12), and the phase change material (PCM). Furthermore, the energy cell (10) comprises a heat exchanging means (16) encompassed by the phase change material (PCM), and comprises a heat transfer media. The heat exchanging means (16) has an Inner surface (18) provided with a number of inner flanges (20), and an outer surface (22) provided with a number of outer flanges (24). The inner flanges (20) are encompassed by the heat transfer media, and the outer flanges (24) are encompassed by the phase change material (PCM), The energy cell (10) also comprises a membrane means (26) arranged in connection to, and being affected by the phase change material (PCM).

Description

AN ENERGY CELL

The present invention rebates to an energy cell operable to generate mechanical energy when a phase change materia! (PCM) changes from solid

The patent document US-4, 186, 558 relates to an engine which utilizes thermal energy to change the state of a liquid between a frozen and melted condition. The engine comprises an outer cylindrical container having an upper end wall and a bottom wall with a parametric side wall, Two ports are connected through the top wall and designed as ports. Two additional ports are connected adjacent to the bottom wall and are designed as ports. Located within the container are a plurality of cyiinders. The cylinders are formed of elongated tubes in which is placed a liquid, A piston head sits on top of the liquid with a piston rod extending from the piston and upward from the cylinder. It will be noted that a plurality of the cylinders are positioned in parallel within the container. A number of openings are provided in the upper wall of the container to permit passage there through of the pistons rods. The upper ends of all of the piston rods are in turn coupled to a disc which serves as the output device. The sequence of bringing in cold fluid followed by hot fluid continues whereby the pistons will reciprocate within the cylinders as the liquid freezes and then returns back to its liquid condition, As a result, the plate will continuously provide vertical movement reciprocally.

The patent document DE-197 22 249_» A1 relates to a heat engine which has a pressure cylinder with a working fluid. The cylinder is surrounded by a ring shaped heat exchanger chamber. A ring shaped sealing dividing wall ^"m the exchanger chamber is moveable in piston direction. It has end-sided connections for separate heat and cooling circuits. The cylinder piston is charged at both ends, and the exchanger chamber is of a corresponding double construction with dividing wall and connections, so that the chambers can be alternatively supplied with heating and cooling medium. The heating and cooling fluid is water, and the dnq fluid is oil. The patent document WO89/127 48 relates to a process and apparatus for conversion of tow value thermal energy into mechanical energy by thermal expansion of an inert liquid expansion medium, which in a relatively low temperature range of not higher than 80 degrees C has a relatively high expansion coefficient, which medium Is contained in pressure tubes included in a regeneration cylinder, which pressure tubes are stepwise heated or cooled by a thermal medium circulating In the cylinder without parts of the thermai medium

medium are paraffins, The patent document FR-2 884 942, A1 relates to a system using the expansion pressure of water which freezes in order to convert it into mechanical energy which can be used as a driving element. According to fig. 1 , the system comprises a pressure generator containing water, a fluid for transmitting the pressure (non-compressible) contained in a shielded pipe, a piston enclosed in z cylinder filled with a second hydraulic fluid, non-return valves mounted on this circuit; the whole system ending up at a hydrostatic motor or mechanical assembly, the in a container. The system can be used in energy converters.

The patent document US-5, 220, 954 relates to a heat exchanger for a phase change material, which comprises a container holding the phase change material, a tube surrounding the container to define an annular space

divide the annular space into at least upper and lower passageways. The heat exchanger can preferably be operated in either a melt cycle or a freeze cycle, In the melt cycle, the tower flow passageway is configured to receive heat exchange fluid to initiate melting of the phase change material from the bottom so that the newly formed liquid phase change material is displaced toward the top of the container, in the freeze cycle, the upper flow passageway receives heat exchange fluid to initiate freezing of the phase change materiai at the top. The newly formed solid phase change materiai falls to the bottom of the container, displacing liquid phase change material toward the top.

A main disadvantage with the above disclosed solutions is that a lot of heat energy is stored m chamber walls, which leads to solutions which are not so The above mentioned problems are solved by an energy cell operable to generate mechanical energy when a phase change material (PCM) changes from solid phase to liquid phase according to Claim 1. The energy cell comprises a housing means holding the phase change materia! (PCM). The energy ceil also comprises an insulating means arranged between the housing means, and the phase change material (PCM), and a heat exchanging means encompassed by the phase change material (PCM) and comprising a heat transfer media, The heat exchanging means has an inner surface provided with a number of inner and an outer surface provided with a numl are encompassed by the heat transfer media, and the outer flanges are encompassed by the phase change material (PCM). The energy cell also rises a membrane means arranged in

A main advantage with the energy cell according to the present invention is that the heat energy stored in the housing walls is minimized. Furthermore, with this energy cell it is possible for the phase change material (PCM) to work under high pressure conditions. Both these advantages leads to increased efficiency. A further advantage in this context is achieved if the housing means, the insulating means, the heat exchanging means and the membrane means have an annular cross section in a plane perpendicular to the main direction of motion of the membrane means.

According to another embodiment, it is an advantage if the housing means, the insulating means and the heat exchanging means have an annular cross section in a piane perpendicular to the main direction of motion of the membrane means, and if the membrane means has a circular shape,

Furthermore, it is an advantage in this context if the heat exchanging means is provided with an end means closing the heat exchanging means in such a way that there is a distance between the membrane means and the end means in a plane parade! to the main direction of motion of the membrane means, allowing the phase change material (PCM) to exists between the end means and the membrane means, and if the heat exchanging means also is provided with a partitioning means in principle, but not completely dividing the tubular heat exchanging means into two half tubes, wherein the partitioning means is not connected to the end means, allowing the heat transfer media to pass between the tltloning means and the end means.

According to another embodiment, it is an advantage if the housing means ating means have an annular cross section in a plane perpendicular to the main direction of motion of the membrane means, and if the heat exchanging means comprises a conduit means in turn comprising an inlet conduit means arranged for inflow of the heat transfer media, an outlet conduit means arranged for outflow of the heat transfer media, and an intermediate conduit means connected between the inlet and outlet conduit means and arranged for flow of the heat transfer media there between, and if the membrane means has a circular shape,

A further advantage in this context is achieved if the inlet conduit means starts, and the outiet conduit means ends on the same side of the energy ceii,

Furthermore, it is an advantage in this context if the conduit means has a substantiaiiy U-shaped cross section in a piane parallel to the main direction of motion of the membrane means, and if the inlet conduit means, and the outiet conduit means each has an annular cross section in a plane perpendicular to the

A further advantage in this context is achieved if the flanges are arranged as spokes.

Furthermore, it is an advantage in this context if the energy cell also comprises a working fluid contained in connection to, and being affected by the

A further advantage in this context is achieved if the energy ceil also comprises a first, insulating bushing means arranged in connection to a first end part of the heat exchanging means, and a second, Insulating bushing means arranged In connection to a second end part of the heat exchanging means.

According to another embodiment, it is an advantage if the energy cell also comprises an insulating bushing means arranged in connection to an end part of the heat exchanging means, which end part is not in connection with the

Furthermore, it is an advantage in this context if the bushing means have/has an annular shaped cross section in a plane perpendicular to the main direction of motion of the membrane means. A further advantage in this context is achieved if lhe heat transfer media is water, oil, or other suitable media in liquid or gas phases.

Furthermore, it is an advantage in this context if the energy cell also comprises a connector means wherefrom the working fluid can flow out, or in, it will be noted that the term "comprises/comprising" as used in this description is intended to denote the presence of a given characteristic, step or component, without excluding the presence of one or more other characteristic features, integers, steps, components or groups thereof.

Embodiments of the invention will now be described with a reference to the accompanying drawings, in which:

Fig. 1 is a sectional view of a first embodiment of an energy cell operable to generate mechanical energy according to the present invention: Fig. 2 is a sectional view of the energy eel! disclosed in Fig. 1 , taken along the section x-x in Fig. 1 ;

Fig. 3 is a sectional view of the energy eel! disciosed in Fig. 1 in the unloaded condition;

Fig. 4 is a sectional view of the energy cell disclosed in Fig. 1 in the compressed condition;

Fig. 5 is a sectional view of the energy cell disclosed in FIg. 1 in the expanded condition;

Fig. 8 is a sectional view of a second embodiment of an energy cell operable to generate mechanical energy according to the present invention; and Fig. 7 is a sectional view of a third embodiment of an energy cell operable to generate mechanical energy according to the present invention.

In fig. 1 there is disclosed a sectional view of a first embodiment of an energy cell 10 operable to generate mechanical energy when a phase change material (PCM) changes from solid phase to liquid phase. The energy ceil 10 comprises a housing means 12 holding the phase change material (PCM). The energy cell 10 also comprises an insulating means 14 arranged between the housing means 12, and the phase change material (PCM). The volume v1 is filled with the phase change material (PCM). As also is apparent in Fig. 1 and 2, the energy cell 10 also comprises a heat exchanging means 18 encompassed by the phase change material (PCM), and comprising a heat transfer media. The heat exchanging means 18 has an inner surface 18 provided with a number of inner flanges 20, and an outer surface 22 provided with a number of outer flanges 24. The inner flanges 20 are encompassed by the heat transfer media, and the outer flanges 24 are encompassed by the phase change material (PCM). As also is apparent in Fig. 1 , the energy cell 10 also comprises a membrane means 26 arranged in connection to, and being affected by the phase change materiai (PCM).

Furthermore, the energy cell 10 also comprises a first, insulating bushing means 301 arranged in connection to a first end part of the heat exchanging means 18, L e. arranged in connection to the membrane means 28. Arranged at the other end part of the heat exchanging means 18, the energy cell 10 comprises a second, insulating bushing means 302.

As is apparent in Fig, 1 and 2, the housing means 12, the insulating means 14, the heat exchanging means 16, and the membrane means 28 all have an annular cross section en a plane perpendicular to the main direction of motion of the membrane means 26. This means that the bushing means 301 , 302 also have an annular cross section in the same plane.

It is pointed out that Fig, 2 only discloses the energy ceil 10 schematically, and not in full scale, or according to scale.

Furthermore, as is apparent in Fig. 2, the flanges 20, 24 are arranged as spokes. It is pointed out that the flanges 20_r 24 are part of the heat exchanging means 18. Although it is not apparent in Fig. 2, the flanges 2O₈ 24 have a trapezoidal cross section seen in the plane of Fig. 2, wherein the truncated apexes of the flanges are pointing outwards. Consequently, the base of the trapezoidal cross section is bigger than the truncated apex of the trapezoidal cross section. This construction leads to both improved thermal conductivity, and improved structural strength. According to another embodiment, not disclosed, the flanges 20, 24 can have a rectangular cross section.

As aiso is apparent in Fig. 1 , the energy cell 10 also comprises a working fluid 28 contained in connection to, and being affected by the membrane means 26. Furthermore, the energy cell 10 also comprises a connector means 32 wherefrom the working fluid 28 can flow out, or in. The arrows disclosed in Fig. 1 disclose the flow direction for the heat transfer media.

The heat transfer media can e. g. be water, oil, or other suitable media in liquid or gas phases. Heat pipes could also be used for heat transfer.

To avoid heat energy to be stored in the housing means 12, the energy ceil 10 is insulated with the insulating means 14, and the insulating bushing means 301 , 302.

The inner and outer flanges 20, 24 are designed to optimize the heat transfer from the heat transfer media to the phase change material (PCM), and

As also is apparent in Fig. 1 , the energy cell 10 aiso comprises a sealing means 400 arranged in connection with the membrane means 28, and being operable to seal the connections of the membrane means 28. to Fig. 3 there is disclosed a sectional view of the energy cell 10 disclosed in Fig. 1 in the unloaded condition. This means that the membrane means 28

in Fig. 4 there is disclosed a sectional view of the energy ceil 10 disclosed in Fig. 1 in the compressed condition. In the cooling phase, the phase change materiai (PCM) has contracted and drags the membrane means 28 downwards. in Fig. 5 there is disclosed a sectional view of the energy cell 10 disclosed in Fig.1 in the expanded condition. During the heating phase, the phase change materia! (PCM) has expanded and bends the membrane means 28 upwards.

In Fig. 8 there is disclosed a sectional view of a second embodiment of an energy cell 10 according Io the present invention. Similar elements in ail Fig. 1-7 have been denoted with the same reference signs and will not be described in detail again. As is apparent in Fig. 6, the housing means 12 and the insulating means 14 have an annular cross section In a plane perpendicular to the main direction of motion of the membrane means 28. On the other hand, the heat exchanging means 16 comprises a conduit means 164 in turn comprising an inlet conduit means 168 arranged for inflow of the heat transfer media, an outlet conduit means 188 arranged for outflow of the heat transfer media, and an intermediate conduit means 170 connected between the inlet and outlet conduit means 188_» 188, and arranged for flow of the heat transfer media there between. The direction of the flow of the heat transfer media is indicated with the arrows in Fig. 6. Furthermore, the membrane means 26 has a circular shape.

As is apparent in Fig. 8, the inlet conduit means 188 starts, and the outlet conduit means 18Θ ends on the same side of the energy cell 10. Furthermore, the conduit means 184 has a substantially U-shaped cross section in a piaπe parallel to the main direction of motion of the membrane means 28. On the other hand, the inlet conduit means 168, and the outlet conduit means 188 each has an annular cross section in a plane perpendicular to the main direction of motion of the membrane means 28. Furthermore, the intermediate conduit means 170 also has an annular cross section but in another plane.

As is apparent in Fig. 8, this energy ceil 10 only comprises one type of insulating bushing means 302 arranged in connection to one end part of the heat exchanging means 18.

In Fig. 7 there is disciosed a sectional view of a third embodiment of the energy ceil 10 according to the present invention, In this particular embodiment, the housing means 12, the insulating means 14 and the heat exchanging means 16 have an annular cross section in a plane perpendicular to the main direction of motion of the membrane means 26. The membrane means 28 has a circuiar

Furthermore, the heat exchanging means 18 is provided with an end means 181 closing the heat exchanging means 18 in such a way that there is a distance between the membrane means 28 and the end means 181 in a plane parallel to the main direction of motion of the membrane means 28. This means that the phase change materiai (PCM) exists between the end means 161 and the membrane means 26. As also is apparent in Fig. 7, the heat exchanging means is also provided with a partitioning means 182 in principle, but not completely dividing the tubular heat exchanging means 16 into two connected half tubes. The partitioning means 162 is not connected to the end means 181. This aliows the heat transfer media to pass between the partitioning means 182 and the end means 161. The direction of flow of the heat transfer media is indicated with the arrows disclosed in Fig. 7.

Ail the different embodiments of the energy cell 10 according to the present invention function in the following way, divided in a heating phase, and a cooling phase. During the heating phase a high temperatured heat transfer media (e. g, water) flows in the heat exchanging means 16. The heat energy is transferred from the heat transfer media to the phase change material (PCM) via the inner and outer flanges 20, 24. This means that the phase change materia! (PCM) gets heated and goes liquid. The phase change material (PCM) expands under high pressure (approximately 800 bar) and bends the membrane means 26 upwards. The moving membrane means 26 makes the working fluid 28 contained in the voiume v2 to flow out of the connector means 32.

During the cooling phase a heat transfer media with low temperature (e. g. water) flows in the heat exchanging means 16. The heat energy is transferred from the phase change materia! (PCM) to the heat transfer media via the outer and inner flanges 20, 24, This means that the phase change materia! (PCM) cools down and goes solid, The phase change material (PCM) contracts and drags the membrane means 28 downwards. The membrane means 28 is also forced down by a light pressure in the working fluid 28 (approximately 10 bar).

The energy cell 10 according to the present Invention can be described as a combined heat exchanger and mechanical energy converter.

The different solutions described above are ail easy and cheap to manufacture. Furthermore, the solution with a membrane means 28 will lead to high efficiency because losses in sealings due to friction are avoided.

The invention is not limited to the embodiments described In the foregoing. It will be obvious that many different modifications are possible within the scope of the following Claims.

Claims

1. An energy cell (10) operable to generate mechanical energy when a phase change material (PCM) changes from solid phase to liquid phase, said energy cell (10) comprises a housing means (12) holding said phase change material (PCM), eharaeteriiec! in that said energy cell (10) also comprises an insulating means (14) arranged between said housing means (12), and said phase change materia! (PCM), and a heat exchanging means (18) encompassed by said phase change materia! (PCM) and comprising a heat transfer media, wherein said heat exchanging means (16) has an inner surface (18) provided with a number of inner flanges (20), and an outer surface (22) provided with a number of outer flanges (24), said inner flanges (20) are encompassed

in that saic ins (26) arranged in connection to, and being affected by said phase change material (PCM),

2, An energy cell (10) according to Claim 1 , characterised in that said housing means (12), said insulating means (14), said heat exchanging means (16) and said membrane means (26) have an annular cross section in a plane perpendicular to the main direction of motion of said

3. An energy ceil (10) according to Claim 1 , characterized in that said housing means (12), said insulating means (14) and said heat exchanging means (16) have an annular cross section in a plane perpendicular to the main direction of motion of said membrane means (28), and in that said membrane means (26) has a circular shape.

4. An energy eel! (10) according to Claim 3, characterized in that said heat exchanging means (18) is provided with an end means (161 ) dosing said heat exchanging means (16) in such a way that there is a distance between said membrane means (26) and said end means (161 ) in a

Jirection of motion c ihase change mat said end means (161 ) and said membrane means (28), and in that said heat exchanging means (16) also is provided with a partitioning means (162) in principle, but not completely dividing said tubular heat exchanging means (16) into two connected half lubes, wherein said partitioning means (162) is not connected to said end means (181 ), aliowing said heat transfer media to pass between said partitioning means (162) and said end means (181 ).

5, An energy cell (10) according to Claim 1 , characterised in that said housing means (12) and said insulating means (14) have an annular cross section in a plane perpendicular to the main direction of motion of said membrane means (28), and in that said heat exchanging means (18) comprises a conduit means (184) in turn comprising an inlet conduit means (188) arranged for inflow of said heat transfer media, an outlet conduit means (168) arranged for outflow of said heat transfer media, and an intermediate conduit means (170) connected between said inlet and outlet conduit means (186, 168) and arranged for flow of said heat transfer media there between, and in that said membrane means (26) has a circular shape,

6, An energy cell (10) according to Claim 5, characterized in that said inlet conduit means (188) starts, and said outlet conduit means (168) ends on the same side of said energy cell (10).

7. An energy cell (10) according to Claim 6, characterized in that said conduit means (164) has a substantially U-shaped cross section in a plane parallel to the main direction of motion of said membrane means (26), and in that said inlet conduit means (166), and said outlet conduit means (168) each has an annular cross section in a plane perpendicular to the main direction of motion of said membrane means (26).

8. An energy cell (10) according to any one of Claims 2-7, characterized in that said flanges (20, 24) are arranged as spokes.

9. An energy cell (10) according to any one of Claims 1 -8, characterised in that said energy cell (10) also comprises a working fluid (28) contained in connection to, and being affected by said membrane means (28).

10. An energy cell (10) according to any one of Claims 1-2, and 8-9 when dependent on Claims 1 or 2, characterixβci in that said energy eel! (10) also comprises a first, insulating bushing means (301 ) arranged in connection to a first, end part of said heat exchanging means (18), and a second, insulating bushing means (302) arranged in connection to a second end part of said heat exchanging means (16).

11. An energy cell (10) according to any one of Claims 1 , 3-7, and 8-9 when dependent on any one of Claims 3-7, characteπ∞d in that said energy eel! (10) aiso comprises an insulating bushing means (302) arranged in connection to an end part of said heat exchanging means (16), which end part is not in connection with said membrane means (28).

12. An energy eel! (10} according to Claim 10 or 11 , when dependent on Claim 2, characterized in that said bushing means (301 , 302; 302) have/has an annular shaped cross section in a plane perpendicular to the main direction of motion of said membrane means (28).

13. An energy ceil (10) according to any one of Claims 1-12, characterized in that said heat transfer media is water, OiI₃ or other suitable media in liquid or gas phases.

14. An energy celi (10) according to any one of Claims 9-13, when dependent on Claim 9, characterized in that said energy cell (10) also comprises a connector means {32} wherefrøm said working fluid (28) can flow out, or in.