HEAT BUFFER SYSTEM AND SYSTEM FOR HEATING TAP WATER AND/OR CENTRAL HEATING WATER

Abstract

 The invention relates to a heat buffer system comprising a flexible container for containing a liquid therein and at least one partition element arranged in the container for dividing the container in at least two compartments, wherein the at least one partition element comprises a plurality of through holes such that the liquid may pass the at least one partition element from a first compartment into another compartment, and wherein said container comprises at least one heat source inlet for feeding liquid heated by a heat source into the container, at least one heat source outlet for discharging liquid from the container to be fed to the heat source, at least one heat use outlet for discharging liquid from the container to a heat exchanger for heating tap water or central heating water and at least one heat use inlet for feeding liquid from the heat exchanger to the container.

Description

[0001] The invention relates to a heat buffer system. In particular the invention relates to a heat buffer system comprising a liquid-tight flexible container for containing a liquid therein, and at least one partition element arranged in the container for dividing the container in at least two compartments, wherein the at least one partition element is arranged such that the at least two compartments are divided from each other in a length or width direction of the container, wherein the at least one partition element comprises a plurality of through holes such that the liquid may pass the at least one partition element from a first compartment into another compartment.

[0002] In the container of the heat buffer system a liquid may be contained, wherein said liquid may for example be water or any other suitable liquid. The at least one partition element provides stability to the container and divides the container in at least two compartments, wherein the liquid may flow through the various compartments of the container via the through holes provided in the partition element. As a result of stratification the liquid in the container will define layers of different temperatures, wherein the warmest liquid will be at the top end of the container and the coldest liquid will be at the bottom of the container and wherein intermediate temperature layers will form in between. The temperature of the liquid thus increases in an upward direction as seen in a height direction of the container. The container may comprise any suitable number of partition elements, wherein the number of compartments is equal to the number of partition elements plus one. The partition elements are preferably arranged orthogonal to the length direction of the container, such that the compartments are arranged next to each other in the length direction of the container. As a result of the flexibility of the container the container may for example be arranged in spaces that are difficult to access, such as for example the space below the ground floor of a building. The flexibility of the container is for example obtained by making the container of a flexible material, such as for example ethylene propylene diene monomer (EPDM) or any other suitable material.

[0003] Such a heat buffer system is for example known from the Dutch patent application NL2024901. It is an object of the invention to improve such known heat buffer system.

[0004] This object is achieved by providing a heat buffer system according to the preamble, wherein said container comprises at least one heat source inlet for feeding liquid heated by a heat source into the container, at least one heat source outlet for discharging liquid from the container to be fed to the heat source, at least one heat use outlet for discharging liquid from the container to a heat exchanger for heating tap water and/or central heating water and at least one heat use inlet for feeding liquid from the heat exchanger to the container.

[0005] The heat buffer system according to the invention provides the advantage that it is a closed system wherein the liquid heated by the at least one heat source is returned to the container after being heated by the at least one heat source and wherein the liquid used for transferring heat to tap water and/or central heating water in the heat exchanger is also returned to the container and may then be reheated by feeding the liquid to the heat source.

[0006] In an embodiment of the heat buffer system according to the invention said plurality of through holes is distributed over a height of the at least one partition element in such a manner that the through holes are provided at at least three different heights of the partition element.

[0007] The applicant has found that by providing the through holes at at least three different heights a better flow of the liquid through the various compartments of the container may be achieved and as a result thereof or as an alternative advantage an improved stratification of the liquid in the container may be obtained. The through holes may be provided at any suitable number of different heights, for example in dependence of the height of the partition element, and may for example be provided at three different heights, or at four different heights, or at five different heights, or at any higher number of different heights.

[0008] The through holes may in particular be evenly distributed over said partition element as seen in a height direction.

[0009] In an embodiment of the heat buffer system according to the invention the plurality of through holes is chosen such that the at least one partition element comprises minimally 8 through holes per m².

[0010] The applicant has found that such a minimum number of through holes per m² provides a better flow of the liquid and/or improved stratification. Another advantage of providing a minimum number of through holes per m² is that the number of through holes is proportional to the size of the partition element, wherein larger sized partition elements may comprise more through holes than smaller sized partition elements.

[0011] Preferably said through holes are evenly distributed over the at least one partition element, both in the height direction as described above and in the length direction of the partition element.

[0012] Such an even distribution may provide an improved flow and/or stratification of the liquid in the container.

[0013] Said through holes may in particular be preferably arranged in a suitable number of rows and columns, wherein the rows are defined int the height direction of the partition element and the columns are defined in the length direction of the partition element. Said number of rows may thus correspond to the number of different heights as described above and may for example be three, four, five, or any higher number. Said number of columns may be any suitable number, such as for example two, three, four, five, six, seven, eight, nine, ten or any higher number of columns. Said number of columns may for example be chosen in correspondence with the length of the partition element.

[0014] The through holes may in particular be provided over substantially the whole area of the partition element, wherein the centre distance between neighbouring through holes may for example be between 10 - 15 cm or any other suitable distance.

[0015] In an embodiment of the heat buffer system according to the invention the system further comprises a frame that is arranged to at least partly surround the container.

[0016] Such a frame may provide additional stability to the container and/or may prevent tearing of the container.

[0017] The frame may be made of any suitable material, such as for example metal.

[0018] The frame may in particular surround the bottom and side wall(s) of the container.

[0019] In an embodiment of the heat buffer system according to the invention the frame is adjustable between a transport state and a use state, wherein in the use state said frame is arranged to surround the container.

[0020] In the transport state the frame may have a compact size, i.e. a smaller size than in the use state of the frame, or may be disconnected into separate parts, such that it is possible to move the frame into a space that is difficult to access. In the use state the frame may have its normal, use shape in which the frame surrounds the container and provides stability to the container.

[0021] Practically the frame comprises a plurality of frame elements, wherein said frame elements are connectable to each other in order to build said frame.

[0022] In an at least partly disconnected state of the frame elements the frame may be in it's transport state and at the installation site of the heat buffer system the frame may easily be transformed into its use state by connecting the frame elements to each other.

[0023] In order to connect the frame elements to each other the system may further comprise connecting means for connecting the frame elements to each other, wherein said connecting means are optionally part of at least some of the frame elements.

[0024] For example bolts and/or screws and/or any other suitable connecting or fastening means may be used to connect the frame elements to each other. In such an embodiment the frame elements may for example comprise strip shaped elements or plate shaped elements. In such an embodiment connection holes may be provided or made in the frame elements in which the bolts or screws can be inserted. Nuts may be used for fixating the bolts or screws.

[0025] Alternatively the connecting means may comprise a hole or recess in which a part, for example an end zone, of a frame element may be inserted. In such an embodiment the frame element may for example be rod shaped. Such connecting means may be provided as separate elements that are connectable to multiple frame elements to interconnect the frame elements, or may alternatively be an integral part of at least some of the frame elements and to which other frame elements may be connected. Practically such connecting means may comprise a sleeve, wherein the end zone of a first frame element can be inserted into one end of the sleeve and the end zone of a second frame element can be inserted into the other end of the sleeve and are thereby connected to each other by means of the sleeve. Such sleeve may as explained above also be an integral part of one of the frame elements and may be provided at the end zone of that frame element. Such a sleeve may have the shape of a I, T or + for respectively interconnecting two, three or four frame elements.

[0026] In stead of providing a frame with separate frame elements that are connectable to each other, it is for example also possible to provide a collapsible frame, wherein the transport state is the collapsed state and the use state is an expanded state of the collapsible frame.

[0027] In an embodiment of the heat buffer system according to the invention the system further comprises at least one reinforcement element for reinforcing said frame.

[0028] Such a reinforcement element and preferably plurality of reinforcement elements may for example be provided at corners of the frame, even more particular at the lower corners of the frame. Such reinforcement element may prevent the frame from bending outwards and thereby provide further stability to the frame and thereby the container.

[0029] The reinforcement element may have any suitable shape. For example, such a reinforcement element may have a substantially triangular shape, wherein the longest side of the triangle may substantially extend between the frame and the floor on which the container is arranged.

[0030] In an embodiment of the heat buffer system according to the invention a first pair is defined by the at least one heat source inlet and the at least one heat use outlet and is provided at a first location of the container, wherein a second pair is defined by the at least one heat source outlet and the at least one heat use inlet and is provided at a second location of the container, and wherein the first and second locations are different.

[0031] By providing the at least one heat source inlet and the at least one heat use outlet as the first pair at the first location and the at least one heat source outlet and the at least one heat use inlet as the second pair at the second, different location it is possible to feed heated liquid from the heat source close to where relatively warm liquid is discharged from the container to be fed to the heat exchanger, and at a distance from the second location where relatively cold liquid is discharged from the container to be fed to the heat source and relatively cold liquid from the heat exchanger is fed into the container.

[0032] A pair is defined here as being relatively close to each other, wherein the at least one heat source inlet and the at least one heat use outlet are at least closer to each other than these are to the at least one heat source outlet and the at least one heat use inlet and vice versa.

[0033] In an embodiment of the heat buffer system according to the invention the first pair connects to one compartment of the container and the second pair connects to a another, different compartment of the container.

[0034] This supports a flow of the liquid throughout the various compartments of the container.

[0035] Preferably said one compartment and said another compartment are the outermost compartments of the container.

[0036] In an embodiment of the heat buffer system according to the invention the first location is higher than the second location as seen in a height direction of the container.

[0037] This allows to feed liquid to and discharge liquid from the container at desired temperatures, i.e. at a relatively high temperature for the at least one heat source inlet and the at least one heat use outlet and at a relatively low temperature for the at least one heat source outlet and the at least one heat use inlet. As such the liquid to be heated by the heat source has a relatively low temperature and may thus be more efficiently heated. The liquid from the heat exchanger that is cooled down in the heat exchanger may be fed into the container at a relatively low height where relatively cold liquid is present. The liquid from the heat source may be fed into the container at a relatively high height where relatively warm liquid is present. The liquid to be fed to the heat exchanger has a relatively high temperature for efficiently heating the tap water and/or central heating water.

[0038] Practically the inlets and outlets of a said pair are arranged at the same height.

[0039] In an embodiment of the heat buffer system according to the invention at least one of the at least one heat source outlet and the at least one heat use outlet comprises a conduit or pipe with an inlet opening that extends to within the container over at least one half of the width or length direction of the container.

[0040] Preferably the inlet end of the conduit or pipe comprising the inlet opening comprises a bent part bending in a substantially downward direction. This may prevent air entering the pipe system.

[0041] As a result thereof liquid is discharged from the container at a distance as seen in the direction in which the conduct or pipe extends as to where liquid is fed to the container. This may prevent a short circuiting of the water.

[0042] As an alternative solution to short circuiting the inlets and outlets may be provided at opposite sides of the container, such that the water is fed into the container and discharged from the container in opposite directions. Such a solution may in particular be possible if there is sufficient space to provide connecting pipes connecting to the inlets and outlets on both sides of the container.

[0043] The conduct or pipe may in particular extend in an opposite direction as to the direction in which the first and second pairs are distanced from each other.

[0044] In an embodiment of the heat buffer system according to the invention the system further comprises isolation means for isolating the container, said isolation means being arranged to surround the container and optionally said frame.

[0045] In an embodiment of the heat buffer system according to the invention the system further comprises a second liquid-tight flexible container that at least partly surrounds at least the container and optionally the frame and/or isolation means.

[0046] Such a second container may collect any liquid in case of a leakage of the container. In such an embodiment the container may be defined as the first container.

[0047] Said second container preferably at least surrounds the bottom and side walls of the container, such that any liquid leaking from the first container will be collected by the second container. Preferably the second container has not top, such that the container may easily be arranged in the second container.

[0048] In an embodiment of the heat buffer system according to the invention said container further comprises a heating means for heating the liquid in the container. Such a heating means may provide additional heating to the liquid present in the container, for example when it is detected that the temperature of the liquid becomes below a desired minimum temperature.

[0049] In an embodiment of the heat buffer system according to the invention said at least one partition element comprises at least one reinforcement element for reinforcing the at least one partition element.

[0050] Preferably two such reinforcement elements are provided, which are arranged at respective longitudinal ends of the partition element. The reinforcement elements preferably extend substantially orthogonal to the main plane of the partition element and in an assembled position substantially parallel to the side wall of the container. As a result of the reinforcement elements the longitudinal ends of the partition elements are substantially T-shaped as seen from above or in a horizontal cross sectional view.

[0051] It is noted that any number of heat sources and any suitable type of heat sources may be used. For example, but not limited thereto, at least one heat pipe may be provided as a heat source, or a solar collector, or a heat pump.

[0052] It is noted that any number of heat exchangers and any suitable type of heat exchangers may be used. Practically one heat exchanger is provided for heating tap water and another heat exchanger is provided for heating central heating water. These are provided as separate heat exchangers to be able to heat the tap water and central heating water to different temperatures. Such heat exchangers may for example, but not limited thereto, be a counterflow heat exchanger.

[0053] The invention also relates to a system for heating tap water and/or central heating water, comprising the heat buffer system as described above in any one or more of the described embodiments and/or having any one or more of the above described features, alone or in any suitable combination, and comprising at least one said heat source for heating the liquid and at least one heat exchanger for heating tap water and/or central heating water, wherein the at least one heat source connects to the heat source inlet for feeding liquid heated by the heat source into the container and to the heat source outlet for feeding liquid from the container to the heat source, and wherein the at least one heat exchanger connects to the heat use inlet for feeding liquid from the heat exchanger into the container and to the heat use outlet for feeding liquid from the container to the heat exchanger.

[0054] Such a system for heating tap water and/or central heating water has the advantage that in particular in relatively warm and/or sunny months the liquid in the heat buffer system may be heated by the at least one heat source. In the summer liquid may be efficiently be heated, for example by means of a heatpipe, solar collector or heat pump. The relatively warm liquid is buffered or stored in the container of the heat buffer system and as a result of the isolation means cooling down of the liquid is limited. The relatively warm liquid may then be used for heating the tap water and/or central heating water, especially also in colder and/or darker months. In addition or alternatively, when the sun is shining in darker months, electric energy from PV-systems may drive a heat pump or other electric heating source for heating the liquid and the heated liquid may be used for heating the tap water and/or central heating water at times when there is no sun. The system for heating tap water and/or central heating water may thus function as a heat battery and may efficiently store thermal energy when it is warm and/or sunny such that the stored thermal energy is ready for use when needed, for example when it is colder or the sun is not shining.

[0055] It is noted that in particular two heat exchangers will be provided, one for heating tap water and one for heating central heating water, but it will be clear for the skilled person that any suitable number of heat exchangers may be provided.

[0056] The number of heat sources may be chosen as desired.

[0057] Preferably one heat use inlet and one heat use outlet is provided per heat exchanger.

[0058] Preferably one heat source inlet and one heat source outlet is provided per heat source.

[0059] The total number of inlets and outlets may thus be dependent on the number of heat sources and heat exchangers.

[0060] The invention may also relate to the use of a system according to the invention.

[0061] The invention will be further elucidated with reference to the attached figures, in which:

Figures 1A and 1B show an exemplary embodiment of the container of the heat buffer system, wherein figure 1A shows a schematic perspective view of the container and figure 1B shows the inside of the container of figure 1A in dotted lines;

Figure 2 shows a schematic perspective view of a frame of the system;

Figure 3 shows the container of figure 1A in the frame of figure 2;

Figure 4 shows a schematic perspective view of a second embodiment of a frame of the system;

Figure 5 shows a schematic perspective view of an isolation means for isolating the container;

Figure 6 shows a schematic perspective view of a second container;

Figure 7 shows a schematic perspective view of the heat buffer system as installed;

Figure 8 is a cross sectional view of the container 1 according to a second embodiment, and

Figure 9 shows a partition element according to an embodiment of the invention in isolation in a schematic perspective view.

[0062] In the figures the same elements are denoted by same reference numerals.

[0063] Figures 1A and 1B show that the heat buffer system in accordance with the invention comprises a liquid-tight flexible container 1 for containing a liquid therein. The container may for example be made of EPDM, which is liquid-tight and flexible and has isolating properties. In this embodiment three partition elements 2 are arranged in the container for dividing the container in four compartments 3. The partitional elements 2 extend orthogonal to a length direction L of the container, such that the compartments 3 are next to other in the length direction. Each partition element 2 comprises in this embodiment thirty through holes 4 such that the liquid may pass the partition elements 2 from a first compartment 3 into another compartment 3. The through holes 4 are provided for creating a flow and/or stratification of the liquid in the container throughout the various compartments 3. The through holes 4 are in this embodiment provided at three different heights and are in this embodiment in particular arranged in three rows of ten through holes 4. For example, the partition element 2 may have a height of about 40 cm and an length of about 1.2 m and may thus in this embodiment have 62.5 through holes per m². It will be clear for the skilled person that any suitable number of through holes 4 may be provided as long as the flow and/or stratification of the liquid in the container 1 is sufficient. The applicant has found that for example a minimum of eight through holes 4 per m² may be sufficient, but it may be preferred to have more through holes 4. The through holes are in this embodiment evenly distributed over the partition element 3, both in a height direction and in a length direction of the partition element. It is noted here that the length direction of the partition element 3 is orthogonal to the length direction L of the container 1. The height direction of the partition element is in the same direction as the height direction H of the container 1.

[0064] Figures 1A and 1B further show that in this embodiment the container 1 comprises two heat source inlets 5 for feeding liquid heated by a heat source into the container 1, two heat source outlets 6 for discharging liquid from the container 1 to be fed to the heat source, two heat use outlets 7 for discharging liquid from the container 1 to a heat exchanger for heating tap water and/or central heating water and two heat use inlets 8 for feeding liquid from the heat exchanger to the container 1. The liquid discharged from the container 1 via the heat source outlets 6 is fed to a respective heat source, for example at least one heat pipe and/or heat pump. This liquid is in this embodiment discharged from a lower part of the container 1 and from the outermost compartment 3 at in this view the left side of the container 1 and may have a relatively low temperature such that it may be efficiently heated by the heat source. After being heated the liquid is fed to the container 1 via the respective heat source inlets 5 which are arranged at a higher part of the container 1 and at the other outermost compartment 3, which is in this view at the right of the container 1. A pump is used for pumping the liquid to the heat source and as a result thereof the liquid flows into the container 1 at a desired flow rate and will flow into the container in a direction substantially orthogonal to the length direction L of the container 1. The liquid discharged from the container 1 via the heat use outlets 7 is fed to a respective heat exchange for heating respectively tap water and central heating water. This liquid is in this embodiment discharged from a higher part of the container 1 and from the same outermost compartment 3 as where the heated liquid from the heat sources is fed into the container and may have a relatively high temperature such that it may be efficiently used for transferring heat to the tap water and central heating water. After passing the heat exchangers the liquid is returned to the container 1 via the respective heat use inlets 8 which are arranged at a lower part of the container 1 and at the same outermost compartment 3 as where the heat source outlets 6 are provided. In accordance with an embodiment of the invention the liquid is thus discharged or fed into the container 1 at a suitable hight in line with the desired stratification of the liquid in the container 1.

[0065] As shown in particular in figure 1A the container 1 may further comprise a vent 9 for venting air from the container 1.

[0066] As shown in particular in figure 1A the container 1 may further comprise a heater 10 for heating the liquid in the container 1. Such heater may for example used when it is measured that the temperature of the liquid in the container 1 is below a desired threshold. The container 1 may further comprise at least one temperature sensor for measuring the temperature of the liquid (not shown).

[0067] Figure 2 shows a frame 20 that is arranged to surround the container 1. In this embodiment the frame 20 comprises a plurality of frame elements 21, which are in this example substantially strip shaped or plate shaped and are in this embodiment made of metal. The frame elements 21 may be moved to the installation side in a disconnected state and may be assembled into the frame 20 at the installation site. In this embodiment bolts 23 and nuts are used for connecting the frame elements 21 to each other. In this embodiment reinforcement elements 22 are provided for reinforcing the frame 20. As shown the reinforcement elements 22 of this exemplary embodiment have a substantially triangular shape and extend between uprights of the frame 20 and the floor on which the frame 20 is installed. These reinforcement elements 22 may provide additional strength and stability to the frame 20 and prevent outward sagging of the frame 20.

[0068] Figure 3 shows the container 1 arranged in the frame 20 wherein the frame 20 partly surrounds the container 1. The frame 20 in particular surrounds the bottom and side walls of the container 1. It is clear from figure 3 that the frame elements 21 are provided such that the inlets and outlets 5 - 8 are accessible for connecting ducts or pipes thereto.

[0069] Figure 4 shows an alternative type of frame 40 that can be used for providing stability to the container 1. In this alternative embodiment the frame 40 comprises a plurality of in this embodiment rod shaped frame elements 41 that may for example be made of metal. Connecting elements 42 comprising sleeve parts may be provided for connecting the frame elements 41 to each other. The connecting elements 41 may have a shape such as to define insertion openings or recesses in a suitable direction for receiving a frame element 41. The frame 40 may be installed at the installation site by connecting the frame elements 41 to each other using the connecting elements 42.

[0070] It will be clear for the skilled person that any suitable type of frame can be used. The frame is preferably provided in a dismounted or collapsed transport state and may be installed or expanded at the installation site.

[0071] Figure 5 shows that an isolation means 50, in this embodiment provided as a isolating shell, is provided to surround the bottom and side walls of the container 1 and frame 20. The isolating shell comprises a plurality of isolating plates that at the installation site are connected to each other, for example by gluing. The isolation plates may be made of any suitable isolation material.

[0072] Figure 6 shows that a second flexible container 60 may be provided that provides a so called bag in bag principle. The second container 60 may for example be made of EPDM and may be arranged to surround at least the container 1 and optionally other parts of the system such as in this embodiment also the frame 20 and isolation means 50. The second container 60 may collect any liquid leaking from the container 1 and may in this embodiment protect the isolation means 50 from outside moisture.

[0073] Figure 7 shows an exemplary embodiment of the complete system as installed. This shows that also the top of the container is covered by the isolation plates, such that the container is completely surrounded by isolating material.

[0074] Figure 8 shows an alternative embodiment of the container 1 wherein the inside of the container 1 is shown with dotted lines. This shows that in this alternative embodiment the heat use outlet 7 comprises a conduit, duct or pipe 80 that extends to within the container 1, such that the liquid that is discharged via the heat use outlet 7 is collected from in this embodiment about 2/3 of the inside of the container 1, as seen from the heat use outlet 7 in a direction orthogonal to the length direction L of the container 1. The free end of the pipe 80, i.e. the inlet end zone of the pipe 80, is in this embodiment bend downwards in order to prevent air entering the system.

[0075] Figure 9 shows a partition element 2 of the container 1 in more detail. This figure 9 shows that the partition element 2 comprises two reinforcement elements 90 that extend substantially orthogonal to the main plane of the partition element 2 and in an assembled position substantially parallel to the side wall of the container 1, wherein a respective reinforcement element is arranged at each longitudinal end of the partition element 2. As a result of the reinforcement elements 90 the longitudinal ends of the partition elements 2 are substantially T-shaped as seen from above or in a horizontal cross sectional view.

[0076] It is noted that only the heat buffer system is shown in figures 1 - 9. It will be clear that the system for heating tap water and/or central heating water may have in addition to the system shown in figures 1 - 9 in this case two heat exchangers and in this case two heat sources, but any suitable number of heat exchangers and/or heat sources may be provided. At least one pump and a plurality of conduits or pipes may be provided for transporting the liquid throughout the system. A control system may be provided for controlling the system. Such elements are well known to the skilled person and are as such not shown. The system may comprise any other suitable features or elements.

[0077] It will be clear for the skilled person that the pipes and conduits for transporting the liquid throughout the system connect to the inlets and outlets 5 - 8 of the container 1. Practically the heat buffer system of figures 1 - 9 is first installed at the installation site and then the pipes and conduits are pushed through the relevant layer(s) of the buffer system at a suitable location corresponding to the location of the inlets and outlets 5 - 8. After connecting the pipes the layer(s) are finished off.

[0078] Although the invention is elucidated above on the basis of a number of specific examples and embodiments, the invention is not limited thereto. Consequently, the scope of the invention is defined by the following claims.

Claims

1. Heat buffer system, said heat buffer system comprising a liquid-tight flexible container for containing a liquid therein, and at least one partition element arranged in the container for dividing the container in at least two compartments, wherein the at least one partition element is arranged such that the at least two compartments are divided from each other in a length or width direction of the container, wherein the at least one partition element comprises a plurality of through holes such that the liquid may pass the at least one partition element from a first compartment into another compartment, characterised in that said container comprises at least one heat source inlet for feeding liquid heated by a heat source into the container, at least one heat source outlet for discharging liquid from the container to be fed to the heat source, at least one heat use outlet for discharging liquid from the container to a heat exchanger for heating tap water or central heating water and at least one heat use inlet for feeding liquid from the heat exchanger to the container.

2. Heat buffer system according to claim 1, wherein said plurality of through holes is distributed over a height of the at least one partition element in such a manner that the through holes are provided at at least three different heights of the partition element.

3. Heat buffer system according to claim 1 or 2, wherein the plurality of through holes is chosen such that the at least one partition element comprises minimally 8 through holes per m².

4. Heat buffer system according to any of the preceding claims, wherein said through holes are evenly distributed over the at least one partition element.

5. Heat buffer system according to any of the preceding claims, further comprising a frame that is arranged to at least partly surround the container.

6. Heat buffer system according to claim 5, wherein the frame is adjustable between a transport state and a use state, wherein in the use state said frame is arranged to surround the container.

7. Heat buffer system according to claim 5 or 6, wherein the frame comprises a plurality of frame elements, and wherein said frame elements are connectable to each other in order to build said frame, said system optionally comprising connecting means for connecting the frame elements to each other, wherein said connecting means are optionally part of at least some of the frame elements.

8. Heat buffer system according to any of claims 5-7, further comprising at least one reinforcement element for reinforcing said frame.

9. Heat buffer system according to any of the preceding claims, wherein a first pair is defined by the at least one heat source inlet and the at least one heat use outlet and is provided at a first location of the container, wherein a second pair is defined by the at least one heat source outlet and the at least one heat use inlet and is provided at a second location of the container, and wherein the first and second locations are different, optionally wherein the first location is higher than the second location as seen in a height direction of the container.

10. Heat buffer system according to claim 9, wherein the first pair connects to one compartment of the container and the second pair connects to a another, different compartment of the container, said one compartment and said another compartment for example being the outermost compartments of the container.

11. Heat buffer system according to any of the preceding claims, wherein at least one of the at least one heat source outlet and the at least one heat use outlet comprises a conduit or pipe with an inlet opening that extends to within the container over at least one half of the width or length direction of the container.

12. Heat buffer system according to any of the preceding claims, further comprising at least one of:

- an isolation means for isolating the container, said isolation means being arranged to surround the container and optionally said frame;

- a second liquid-tight flexible container that at least partly surrounds at least the container and optionally the frame and/or isolation means.

13. Heat buffer system according to any of the preceding claims, wherein said container further comprises a heating means for heating the liquid in the container.

14. Heat buffer system according to any of the preceding claims, wherein said at least one partition element comprises at least one reinforcement element for reinforcing the at least one partition element.

15. System for heating tap water and/or central heating water, comprising the heat buffer system according to any of the preceding claims, and comprising at least one said heat source for heating the liquid and at least one heat exchanger for heating tap water and/or central heating water, wherein the at least one heat source connects to the heat source inlet for feeding liquid heated by the heat source into the container and to the heat source outlet for feeding liquid from the container to the heat source, and wherein the at least one heat exchanger connects to the heat use inlet for feeding liquid from the heat exchanger into the container and to the heat use outlet for feeding liquid from the container to the heat exchanger.

Drawing