Method and device for storing heat

Abstract

NOT VISIBLE DUE TO STATUS OF PATENT

Description

[0001] Method and device for storing heat

[0002] The present invention relates to a method for generating a flow of warm, heat-transporting fluid from a layered heat accumulator having a cold side and a warm side, and to a heat accumulator for carrying out this method.

[0003] Among many other applications, heat storage systems are used in power plants, particularly solar power plants, where they must be designed for a 24-hour cycle, allowing them to be charged with heat during the day and discharged at night. In a solar power plant, solar heat is concentrated in a receiver and transferred from it via a heat-transporting fluid, either directly to a consumer or to a heat storage system to provide heat when solar radiation is lacking, especially during the night, so a 24-hour charging / discharging cycle must be possible.

[0004] Many industrial processes are potentially suitable as consumers, and increasingly so are processes in which syngas is produced in a thermochemical reactor. This syngas contains, for example, the gases H2 (hydrogen) and CO (carbon monoxide), from which synthetic fuel is then produced, for example, using the Fischer-Tropsch process. The production of syngas as a precursor to synthetic fuels using solar energy is generally known to those skilled in the art, as is the production of synthetic fuels from syngas, for example, using the Fischer-Tropsch process.

[0005] The thermochemical reactor requires heat at temperatures above 1000 °C, which is supplied to the reactor, for example, by the heat-transporting fluid heated in the receiver or in the heat storage, whereby the cold fluid still has a temperature of 500 °C or more after the heat has been released in the reactor.

[0006] This results in the need for a heat storage device that can be loaded by a loading circuit of heat-transporting fluid and discharged by a discharge circuit of heat-transporting fluid, wherein the stored heat is at an upper temperature t0 of, for example, 1000 C to 1500 C or more and in the discharged heat storage device there is still a lower temperature t ufrom, for example, 500°C to 900°C. In contrast to a sensible heat storage device, the discharge of the heat storage device must be constant at the upper temperature t0 and must not fluctuate or drop during discharge (within defined tolerances), as otherwise a thermochemical reactor could not be operated with the stored heat. Furthermore, the constant consumption of heat in the reactor leads to an equally constant cooling of the heat-transporting fluid in the discharge circuit, so that the temperature of the cold fluid returning to the heat storage device also remains at a constant level.

[0007] Heat storage systems for larger heat quantities are known as cowpers or regenerators, are used in blast furnaces, and accordingly have cycle times of 30 to 60 minutes. Stacked, refractory lattice blocks with fluid flow through them are used to store the heat, with stacks reaching considerable heights of up to 30 m. A disadvantage of cowpers or regenerators is that burners often have to be switched on or cold air has to be mixed with the warm fluid to maintain its upper temperature at the level required for the blast furnace. A further disadvantage is that such heat storage systems are not suitable for 24-hour operation. In addition, the flow resistance as the fluid passes through is high, although the corresponding reduced efficiency is not a major issue in blast furnace operation.

[0008] WO 2012 / 027 854 discloses a heat storage device which appears to fundamentally fulfil the conditions mentioned above for operation in, for example, a solar power plant, and stores the heat in a solid such as gravel which is located in a container and through which the heat-transporting fluid can flow. Warm fluid flows into the gravel filling from one side and heats it from the connection for the warm fluid, whereby the fluid cools down and leaves the gravel filling cold via the connection for the fluid discharge. In the gravel filling, a temperature jump occurs in the direction of flow of the fluid between the already heated gravel and the still cold gravel, i.e. a thermocline which, as the heat storage device progresses, migrates from the connection for the warm fluid through the gravel filling to the connection for the fluid discharge.To discharge this heat storage device, the fluid is fed in the opposite direction through the gravel filling, whereby the thermocline then moves back to the connection for the warm fluid. If this heat storage device is deliberately operated in such a way that the thermocline does not reach any of the connections, but rather the flow direction of the fluid is reversed (or stopped) in good time, the gravel filling is always warm at the connection for the warm fluid and always cold at the connection for the cold fluid. This should result in a constant upper temperature when discharging the disclosed heat storage device, without the need for additional heat from a burner or for the upper temperature to be reduced to its desired level by adding cold fluid. Since the gravel filling heats up or cools down layer by layer with the moving thermocline.to cool down, a heat storage device according to WO '854 is also referred to as a layered heat storage device, which has a cold and a warm side.

[0009] WO 2016 / 162 839 also discloses such heat storage devices in which the thermocline is designed as a wave for the recuperation of heat during the operation of a reactor for the production of syngas.

[0010] The advantage of heat storage systems according to WO '854 and WO '839, which have a cold and a warm side, is that there should be a constant temperature on the warm side, i.e. the effort required for the additional mixing of heated or cooled fluid can be eliminated. The disadvantage, however, is that the thermocline does not actually move at a uniform speed in the cross-section relative to the direction of flow of the fluid. In addition, the temperature gradient in the thermocline across this cross-section is uneven and generally quite small. It ultimately becomes considerably smaller during continuous operation. With the result that the amount of heat that can be stored cannot be determined precisely and can also decrease with continuous operation, so that such a heat storage system is only suitable to a limited extent for use in industrial operations. In addition, the flow resistance in the fluid as it passes through the gravel filling is high and the efficiency is correspondingly reduced.

[0011] Accordingly, it is the object of the invention to provide an improved method for storing heat or an improved heat storage device, wherein the storage of heat can be carried out in a 24-hour cycle unchanged and with high efficiency and the upper temperature t0 does not have to be kept constant by additional aids such as burners.

[0012] This object is achieved by a method having the features of claim 1 or by a heat accumulator having the features of claim 13. By providing a throttle arrangement in the fluid flow, said flow has the same pressure over the entire dimension of the heat-storing solid, regardless of the respective path of a partial flow of the fluid, with the result that the fluid flows uniformly over the entire dimension of the solid, which in turn allows a controlled thermocline to be formed in the solid, which extends uniformly transversely to the flow direction, has a high temperature gradient and a significantly reduced drift over time.These effects become significant as soon as the pressure drop due to the throttling is at least 30% of the total pressure drop in the fluid between the connections, whereby even a pressure drop due to the throttling of 90% is advantageous and thus an efficiency loss caused by the throttling is negligible in view of the advantageous properties of such a heat storage device, since other efficiency-reducing measures for controlling the temperatures can be omitted.

[0013] The fact that, according to claim 8, the lattice modules form a stack with continuous, uninterrupted, and straight heat exchange channels, in combination with the fluid throttle arrangement, results in a particularly advantageously designed thermocline in the lattice modules, with a very high and stable temperature gradient over the entire dimensions of the stack of lattice modules during operation, which leads to high utilization of the stack and a uniform upper temperature t0 within comparatively narrow tolerances during discharge of the heat storage device. This arrangement also exhibits a particularly low flow resistance.

[0014] In addition to the stated object, according to claim 19, the arrangement of the stack of lattice building blocks on supports which form fluid channels enables a structurally simple and thus cost-effective support of the considerable weight of the stack in conjunction with the supply of cold fluid (but nevertheless having a temperature of 900 °C, for example) through the support to the lower side of the stack, which supply is particularly designed according to the invention.

[0015] Further preferred embodiments have the features of the dependent claims.

[0016] The invention is described in more detail below with reference to the figures.

[0017] It shows: Figure 1 schematically a solar power plant with the associated infrastructure,

[0018] Figure 2 schematically shows the temperature conditions in a heat storage device according to the invention,

[0019] Figure 3a schematically shows a heat accumulator according to the invention in a view from the outside,

[0020] Figure 3b shows schematically a section along plane A of Figure 3a,

[0021] Figure 3c shows schematically a section along plane B of Figure 3a,

[0022] Figure 4a shows a view of a lattice module according to the invention,

[0023] Figure 5a shows a view of the stack of lattice blocks and its storage,

[0024] Figure 5b is a view of the stack of Figure 5a with an embodiment of a throttle arrangement,

[0025] Figure 6a is a view of a distribution grid module according to the invention,

[0026] Figure 6b is a view of a section of the stack of lattice blocks with a layer of distribution lattice blocks from below, and.

[0027] Figure 7 is a view of a throttle grid module according to the invention, which represents a further embodiment of a throttle arrangement.

[0028] Figure 1 shows an example of a diagram of a solar power plant 1 with an array of solar collectors 2 irradiated by the sun, which direct the sun's rays 3 onto a receiver 4 arranged on a tower 5. In the receiver 4, heat-transporting fluid is heated. The warm fluid passes via a fluid feed line 6 either to a heat storage unit 7 or to a thermoreactor 8 (or to both simultaneously), where it releases its heat in the heat storage unit 7 and / or drives the thermoreactor 8 with its heat, and then passes as a cold fluid via a fluid return line 9 back to the receiver 4, which heats it again. Via the lines 6, 9, the heat storage unit

[0029] 7 or the thermoreactor 8 or both at the same time, are supplied with heat in the circuit.

[0030] If the heat storage 7 is loaded with heat, it can be discharged by bringing its stored heat through a discharge line 10 through warm, heat-transporting fluid to the thermoreactor 8, where the fluid is heated by the operation of the thermoreactor

[0031] 8 cools and returns to the heat storage unit 7 as cold fluid via a second return line 11. The fluid feed line 6 and the fluid return line 9 thus form a charging circuit, while the discharge line 10 and the second return line 11 form a discharging circuit for the heat storage unit 7. The heat storage unit 7 is generally charged during the day and discharged overnight, resulting in a 24-hour cycle for the heat storage unit 7.

[0032] As mentioned above, the thermoreactor 8 produces H2 and CO, i.e., syngas, from CO2 and H2O, for example. CO2 and H2O are fed to it via a reactor feed line 12 from a suitable source known to those skilled in the art and symbolized by the arrow 22. The produced H2 and CO are conveyed via a production line 13 to an installation 14 for further processing. As also mentioned above, the installation 14 can produce synthetic fuel from the syngas, for example, using the Fischer-Tropsch process.

[0033] A system according to Figure 1 is basically known to the person skilled in the art, as is the fact that the simple, cost-effective and reliable storage of heat in the above-mentioned temperature ranges is unsolved, especially when heat is to be stored on an industrial scale, e.g. the heat of a daily production of a large solar power plant.

[0034] Figures 2a and b schematically show the temperature conditions in a heat accumulator 7 designed according to the invention, which is constructed as a layered heat accumulator with a cold side and a warm side. Figure 2a shows a discharged heat accumulator, and Figure 2b shows a charged heat accumulator with the corresponding temperature distribution.

[0035] Figure 2a, left, schematically shows an embodiment of the heat accumulator 7 in a section along its height H, which is discharged and thus prior to the charging process. The heat accumulator 7 has a connection 15 at the top for the fluid feed line 6 (Figure 1) for the supply of warm fluid (symbolized by the arrow 16) and, at the bottom, in its base area 17, a connection 18 of the fluid return line 9 (Figure 1) for the discharge of cold fluid (symbolized by the arrow 19) back to the receiver 4 (Figure 1). Between the connections 15, 18, the fluid flows from top to bottom through the heat accumulator 7.

[0036] The heat accumulator 7 contains a filling of heat-storing solid material located in the fluid flow and exchanging heat with it. Here, this solid material is in the form of a stack 20 of lattice blocks 21, as described in detail below, including in the description of Figures 5a to 6. In the section shown, the stack has a width B of its base area 17 across its height H, the depth of which is also B in the case of a cubic stack.

[0037] Between the connection 15 and the stack 20 there is a warm fluid chamber 24 in which warm, inflowing (arrow 16) fluid is distributed into the lattice building blocks 21 of the layer 27 or warm, outflowing fluid (arrow 37 of Figure 2b) from the lattice building blocks 21 of the layer 27 collects towards the connection 15.

[0038] Below the stack of lattice blocks 21, between the connection 18 and the lowest layer of lattice blocks 21, there is a cold fluid chamber 23 through which cold fluid exiting the lowest layer 33 of lattice blocks 21 is collected and guided into the cold connection 18, or cold incoming fluid (arrow 36 of Figure 2b) is distributed to the lowest layer of lattice blocks 21. The cold fluid chamber 23 has a throttle arrangement 22 for the fluid flow, which causes a pressure drop in the fluid flowing through it.

[0039] In Figure 2a, right, a diagram 25 is shown with the temperature distribution over the height H of the stack 20 (as mentioned in the discharged state of the heat accumulator 7).

[0040] On the horizontal axis of diagram 25, the temperature T is plotted against the temperatures t uand t0, on the vertical axis the running height h, up to the height H of the stack. From the temperature curve 26 it can be seen that all lattice building blocks 21 have the temperature t u and are therefore cold, with the exception of the layer 27 of warm lattice components 21 with temperature t0, located directly at the connection 15, and the subsequent layer 28 of less warm lattice components 21 with a temperature between t0 and t u lying average temperature. The lattice building blocks 21 of layer 29 are, as mentioned, already cold. The warm lattice building blocks 21 are symbolized by four dots, the less warm ones by one dot, and the cold lattice building blocks by no dots.

[0041] The temperature curve 26 shows an advantageously steep thermocline 26* from t0 to t over the height h u , which extends only over the two layers 21 and 22. The temperature gradient of the thermocline 26* is large.

[0042] If warm fluid (arrow 16) flows into the stack 17 in the direction of flow for loading the heat storage 7, it passes through all the lattice components 21 of the layer 27 without heat exchange with them, as they are warm, but gives heat to the layer below

[0043] 28 until it is warm and at the same time heats the layer further below

[0044] 29 to the average temperature, while the layer below layer 29 remains cold. As the fluid flow continues, more and more layers become warm from top to bottom, while the layers further down remain cold. The thermocline of curve 26 thus moves downwards according to arrow 26'. The charging process of heat storage 7 now continues until only the lowest layer 33 of the underlying layers 30 to 33 is cold, whereupon heat storage 7 is fully charged and, as shown in Figure 2b, the thermocline has thus reached the lowest layer 33.

[0045] Figure 2b shows, in the same representation as in Figure 2a, the heat storage device 7 in a charged state, ready for discharge. The temperature curve 26' shows a thermocline 35*, which - since the heat storage device 7 is charged - has migrated completely downwards in the stack 20 and is advantageously only slightly flatter over the height h than the thermocline 26* of Figure 2a, thus extending over two layers 31 and 32 in the schematic representation of the lattice building blocks 21. The reason for the somewhat flatter formation is that, during the charging phase, due to the heat exchange of the fluid with the lattice building blocks 21, these naturally do not heat the fluid exactly to t u can cool down, meaning the cold fluid flows with a minimally increased temperature toward the next cold layer, where it becomes colder again. This effect continues until the heat storage unit 7 is fully charged and generally leads to a flattening of the thermocline 26** (which, however, is small in this case).

[0046] The charged heat accumulator 7 can now be discharged again by reversing the flow direction of the fluid (compared to Figure 2a), whereby cold fluid (arrow 36) then flows in the discharge flow direction through the connection 18 into a fluid supply line arrangement 23, is throttled in the throttle arrangement 22, flows through the stack 20, heats up therein, and is discharged as warm fluid (arrow 37) through the connection 15. With increasing discharge of the heat accumulator 7, the thermocline 35* migrates upwards again according to the arrow 35', whereby the warm layers 27 to 32 cool down again in the opposite manner to their heating, until finally, when the heat accumulator 7 is discharged, the state according to Figure 2a is again present.

[0047] The throttle arrangement 23, preferably designed as a perforated orifice plate, causes a volume flow of fluid through it that is uniform across its dimensions, with the result that fluid flowing in from the connection 18 flows into the throttle arrangement 23 over the entire surface of the lowest layer 33 of the lattice modules 21 with the same pressure and mass flow, which in turn basically results in the same heat transfer in each lattice module 21 as is the case in its neighboring lattice modules 21 of a respective layer 27 to 33, so that the thermocline is formed transversely to the flow direction at the same height h of the stack 20 and with the same steepness in the flow direction.

[0048] In principle, the throttle assembly 23 can also be arranged in the warm fluid chamber 24, or at any height h in the stack, since a uniform volume flow downstream of the throttle assembly naturally corresponds to a uniform volume flow upstream of the throttle assembly. When charging the heat accumulator according to Figure 2a, the throttle assembly is also located downstream of the stack 20 in the flow direction, and not upstream of the stack 20, as is the case when discharging the heat accumulator 7 according to Figure 2b.

[0049] The effect of the throttle arrangement 20 is particularly favorable, however, when it is provided in the cold fluid chamber 23. Even with very good insulation of the stack 20, the outer lattice modules 21 have a slightly lower temperature than those inside the stack 20. If the throttle arrangement 20 is now arranged in the warm fluid chamber 24 and the heat accumulator 7 is discharged, the volume flow of the fluid is uniform across its dimensions, but not the mass flow: on the outside of the stack 20, determined by the slightly lower temperature of the lattice modules 21, the density of the fluid is slightly higher in accordance with the temperature difference, with the result that the fluid flowing from the cold fluid chamber 23 to the warm fluid chamber 24 absorbs slightly more heat from the lattice modules 21, thus cooling them slightly more than the inner lattice modules 21.Due to the different mass flow (at the same volume flow) through the throttle arrangement 20, the thermocline is undesirably distorted slightly, so that it lies somewhat closer to the cold chamber 23 in the core of the stack.

[0050] If the throttle arrangement 20 is arranged in the cold fluid chamber 23, the volume flow is the same across the dimensions of the throttle arrangement, and also the passing mass flow (the passing fluid has a uniform temperature t u ). Equal mass flow through all lattice components results in a more stable, less distorted thermocline, which is advantageous.

[0051] When the heat accumulator 7 is charged, the effect of the different fluid / mass flow is smaller because the temperature in the cold fluid chamber is lower. The advantage of arranging the throttle assembly 20 in the cold fluid chamber 23 for discharging the heat accumulator 7 is thus not negated during the charging of the heat accumulator 7, so that the advantage ultimately outweighs the disadvantage.

[0052] In contrast to the prior art, a more uniform temperature distribution and steeper thermocline can be realized in the heat storage device 7 according to the invention, which leads to a significantly more uniform temperature release from the heat storage device and also to better utilization of the stack 20 or, for a given stack 20, to the storage of a larger amount of heat. Storing a larger amount of heat for a given stack 20, i.e., an increased storage density, is particularly important for storing large amounts of heat: the necessary insulation of a smaller stack volume is simpler and more cost-effective, and thus easier to achieve.

[0053] Figure 3a schematically shows an embodiment of a heat accumulator 40 according to the invention from the outside, i.e., the surface of its insulation, with a cold side 41 and a warm side 42, a projecting area 43, and the corresponding connections 18 for cold fluid and 15 for warm fluid. The heat accumulator 40 has a base area 44 (not visible in the figure), a front side 45, a rear side 46 (not visible in the figure), a right side 47, a left side 48 (not visible in the figure), and a top side 49.

[0054] During the discharge of the heat accumulator 40, the heat-transporting fluid flows from the cold fluid supply port 18 through the heat accumulator 40 under a pressure drop in the discharge flow direction and exits it through the warm fluid discharge port 15. As mentioned above, the charging flow direction is reversed from port 15 to port 18.

[0055] The dash-dotted line A denotes a section line of a first vertical section plane through the heat accumulator 40 over its entire height H, the dash-dotted line B denotes a section line of a second vertical section plane through the projecting area 43.

[0056] Figure 3b shows the section through the heat accumulator 40 in the first vertical section plane according to section line A of Figure 3a. An insulation 50 surrounds a filling of heat-storing solid material, here a stack 51 of lattice modules 52 shown schematically in the figure according to Figure 4. The stack 51 is supplemented by a layer 52 of distributor lattice modules 53 according to Figure 6a or throttle-distributor lattice modules 54 according to Figure 6b.

[0057] The stack 51, with the layer 52 of distributor-grid modules 53 or throttle-distributor-grid modules 54, rests on a fluid line arrangement 55 of the cold fluid chamber 65, which is designed to support the stack 51 with the supplementary layer 52 and, at the same time, to supply the cold fluid supplied to the heat accumulator 40 through the connection 18 (Figure 3a) evenly to the layer 52 so that it can enter the layer 52 (and the stack 51) at the same pressure, distributed over the entire base area 56 of the layer 52 (and the stack 51). Finally, the fluid line arrangement 55 rests on an insulated base plate 57 of the heat accumulator 40.

[0058] A fluid line arrangement 55 is shown in Figures 5a and b in a view, can support the load of a stack 51 of up to several thousand tons at a lower temperature t uof, for example, up to 900°C (the fluid line arrangement heats up to this temperature during operation with the stack) and is of simple and cost-effective construction. It has a pressure equalisation chamber 58 downstream of connection 18 in the discharge flow direction, then a perforated orifice plate 59 of the fluid throttle arrangement (see Figures 2a, b and 3c and 5b) and finally fluid channels 60 formed by U-beams 61 (see also Figure 5a). The U-beams 61 are connected to the perforated orifice plate 59 at their front and closed at their rear, but are open at the top so that fluid entering them from the pressure equalisation chamber 58 through the perforated orifice plate 59 can flow upwards over their entire length into the layer 52 and thus into the stack 51.The pressure equalization chamber 58 serves to calm the fluid entering via the connection 18 indicated by dashed lines in Figure 3b and to establish at least approximately the same pressure in the fluid in front of the orifice plate 59 and across its entire dimensions. The orifice plate 59 ensures that, upon discharging the heat accumulator 40, each fluid channel 60 is supplied with the same volume and thus also with the same mass flow of fluid (the fluid has a uniform density, corresponding to the lower temperature t). u ). The same pressure builds up in each fluid channel 60, with the result that each lattice component 53, 54 and 52 is supplied with fluid equally.

[0059] It follows that a pressure equalization chamber is preferably provided between the connection for the supply of fluid and the throttle arrangement, and more preferably, the throttle arrangement is arranged below the stack.

[0060] Finally, Figure 3b shows the warm chamber 62 in the warm area 42 of the heat accumulator 40, in which the warm fluid leaving the stack 51 in the discharge flow direction collects so that it can leave the heat accumulator 40 through the connection 15 indicated by dashed lines.

[0061] Figure 3c shows the section through the heat accumulator 40 in the second vertical section plane according to section line B of Figures 3a and 3b. The view is from the front, ie in Figure 3b from left to right, toward the rear side 46 of the heat accumulator 40.

[0062] Visible is the connection 18, which leads into the pressure equalization chamber 58. On the rear side of which (as viewed) is arranged the perforated orifice 59 of the fluid throttle assembly. This assembly is composed of sections 59', each of which covers the openings of the U-beams 61. The U-beams 61 are arranged parallel to one another and spaced apart from one another by spacers 63, and extend perpendicular to the plane of the drawing from there to the rear, underneath the entire stack 51. On the sides of the pressure equalization chamber 58, there is half a spacer element 63' and half a section 59" of the perforated orifice 59. Cover plates 64 rest on top of the U-beams between the perforated orifice 59 and the stack 51. Behind each section 59', 59" extends a fluid channel 60 formed by the U-beams 61.

[0063] The cold fluid flowing into the pressure equalization chamber 58 through the connection 18 in the discharge flow direction is distributed therein, flows through the sections 59', 59" of the perforated plate 59 and thus reaches the fluid channels 60, which extend over the entire base area 56 (see also Figure 3b). The U-beams 61, spacer elements 63, 63' and the sections 59', 59" of the perforated plate 59 are preferably made of the same refractory material as the lattice modules 52, 53 and 54, and are thus easy to manufacture, pressure-resistant and cost-effective.

[0064] The cold fluid is throttled to a predetermined degree as it passes through the perforated orifice 59 of the throttle assembly, namely such that during the discharge of the heat accumulator 40, the pressure drop due to the throttling amounts to 30% to 90% of the total pressure drop in the fluid between the connections 18 and 15. This ensures the uniform supply of fluid to the grid modules 53, 54, and 52 described in Figure 3b.

[0065] It turns out that the throttle arrangement preferably has a perforated orifice plate which is arranged on the side of the fluid supply line under the stack on the front side of the fluid channels and operatively covers the inlet into the fluid channels.

[0066] This results in a method for discharging heat from a layered heat accumulator 40 having a cold side 41 and a warm side 42, through which a heat-transporting fluid flows, and which is filled with heat-storing solid material lying in the fluid flow and exchanging heat with the fluid, wherein the fluid has a pressure drop between a connection for the supply line 18 of cold, heat-transporting fluid and a connection 15 for the discharge of the heat-transporting fluid, which is warm after the absorption of heat, and wherein the fluid, during the discharge of the heat accumulator 40, slides in the discharge flow direction between the connection for the supply line 18 and the connection for the discharge 15 through a throttle arrangement and is throttled in this such that the pressure drop due to the throttling is 30% to 90% of the total pressure drop in the fluid between the two connections.Preferably, the pressure drop in the fluid due to the throttling is more than 40%, preferably more than 50%, particularly preferably more than 60%, very preferably more than 70% or more than 80%. Furthermore, a method is provided, according to which, for at least partial throttling, the fluid flow is passed through a perforated orifice plate, preferably arranged upstream of the solid, located in the fluid flow, and throttling the latter. Furthermore, the fluid to be heated is preferably passed in the fluid line arrangement into a fluid pressure equalization chamber and at least partially throttled at its outlet.

[0067] Figure 4 shows a view of an embodiment of a lattice module 70 according to the invention, which is designed as a stackable cuboid, stands on its base surface, and is vertically interspersed with a number of heat exchange channels 71. Preferably, two raised areas 72 on the upper side are formed opposite two recesses in the base surface, such that a further lattice module 70, placed on the lattice module 70 shown or stacked on it, is centered on it, such that the heat exchange channels 71 of both lattice modules are aligned with one another.

[0068] Grooves 71' are arranged on the side walls 74 of the lattice block 70, the contours of which correspond to half a heat exchange channel 71. If two lattice blocks 70 are placed side by side (or end to end) next to one another, the then opposing grooves 71' together form a heat exchange channel 71. Grooves 71" are arranged at the corners of the lattice block 70, the contours of which correspond to a quarter of a heat exchange channel 71. If four lattice blocks 70 are placed next to one another so that one corner abuts the corner of the other lattice blocks 70, the four adjacent grooves 71" together form a heat exchange channel 71.For example, this design of the lattice building blocks 70 allows a gap-free stacking of the lattice building blocks 70 to form a stack 50 (Figure 3b), wherein the heat exchange channels 71 and the heat exchange channels 71 formed from grooves 71', 71" are then arranged in a regular pattern that extends over all lattice building blocks 70 of the stack 51.

[0069] This results in a stackable lattice module 70 for a layered heat storage device, with a support surface and a surface and side surfaces, and with heat exchange channels running from the support surface to the surface, wherein these are preferably arranged parallel and equidistant from one another, are round in cross-section, have an effective diameter of 50 mm or less, and wherein the distance (wall thickness between the channels) between adjacent heat exchange channels is 70 mm or less. More preferably, the diameter of the heat exchange channels of a lattice module is 25 mm or less, preferably 15 mm or less, very preferably 10 mm or less, and particularly preferably 5 mm.Finally, the distance between adjacent heat exchange channels can preferably be 50 mm or less, more preferably 30 mm or less, furthermore preferably 10 mm or less, very preferably 8 mm or less, preferably 6 mm or less, but at least three times the average grain diameter of the lattice block material. Refractory lattice blocks for Cowpers or regenerators are known to those skilled in the art, including the material from which they can be made and their production, including by casting. The lattice blocks according to the present invention can preferably be made of such materials and produced by casting.

[0070] For example, a lattice module 70 according to Figure 4 can be used as lattice module 52 in the heat accumulator 40 according to Figures 3a to 3c, such that the stack 51 is formed from lattice modules 70. The heat exchange channels 71 of the stacked lattice modules 70 are then aligned and each form a heat exchange channel 71* extending through the entire stack 51, as shown as an example in the stack 51 in Figure 3b. Then, preferably according to Figure 3b, the heat exchange channels of the stack run vertically, and the connection for the supply of cold, heat-transporting fluid is arranged below the stack. The discharge flow direction is then preferably directed vertically from bottom to top.

[0071] The comparatively small diameters of the heat exchange channels 71 (or the grooves 71', 71") are advantageous because they result in a favorable large surface area of ​​the walls of the heat exchange channels 71 relative to the flowing volume of fluid, which promotes heat transfer between the fluid and the lattice module 70. Such small diameters are possible because the supply through the fluid line arrangement 55 in the cold fluid chamber 65 ensures that each heat exchange channel 71* is supplied with the same fluid pressure. In order to produce the walls of the heat exchange channels 71 or the continuous heat exchange channels 71* perfectly in one casting process, their diameter should be at least three times the average grain diameter of the material of the lattice module - conversely, this means that such small diameters, unknown in the prior art, are possible according to the invention.It turns out that the fluid is preferably passed through a solid material designed as a stack of lattice building blocks, wherein the lattice building blocks have parallel, separate heat exchange channels, preferably with the same cross section and preferably with the same distance from one another, and wherein the lattice building blocks are aligned with one another in such a way that the heat exchange channels of lattice building blocks arranged one behind the other in the flow direction are aligned with one another, so that aligned heat exchange channels together each form a straight, uninterrupted heat exchange channel through the stack, which is separated from the other heat exchange channels. In this case, the fluid is preferably passed through heat exchange channels arranged in the solid material, which have the same cross section and the same length and are arranged separately from one another at the same distance from one another.

[0072] From Figure 3b, for example, it can be seen that during the discharge of the heat accumulator, the fluid is preferably conducted from the supply connection to the solid and then through separate heat exchange channels arranged in the solid. Furthermore, it is preferred that the fluid is conducted via a cold fluid chamber having a fluid line arrangement to the solid and preferably to heat exchange channels arranged in the solid.

[0073] To illustrate a portion of the fluid line arrangement 55 of the cold fluid chamber 23 (Figures 2a, b and 3a to c), Figure 5a shows a view of a stack 51 of lattice blocks 70 mounted on supports (multi-part in the figure) designed as U-beams 61, as shown in Figures 3a to 3c. The U-beams 61 have lateral, upwardly directed legs 51', 51", which are connected to one another by connecting sections 51"'. Furthermore, the U-beams 61 are held parallel and spaced apart by spacer elements 63, wherein the spacer elements 63 are dimensioned such that the legs 51', 51" of all U-beams 61 are equally spaced from one another and thus form fluid channels 60 of identical dimensions that extend beneath the entire underside of the stack 51.The fluid is supplied to one side of the fluid channels 60, while the other side is closed, so that during the discharge process, as mentioned above, supplied fluid must inevitably enter upwards into the heat exchange channels 71* of the stack 51. The weight of the stack 51 rests on the U-beams 61, which are preferably made of the same material as the lattice blocks 70, so that they are fireproof, i.e., resistant to the temperatures prevailing in the heat storage unit. This material is also pressure-resistant, so that it can bear the weight of the stack 51. The advantage of the support provided by the U-beams 61 is that in combination they enable a fluid line arrangement for the uniform supply of fluid over the entire base area of ​​the stack 51 and the support of the considerable weight of the stack 51, whereby the manufacturing outlay for this is very low.

[0074] A preferred heat storage device is one in which the cold fluid chamber has a number of supports arranged next to one another below the stack, which support the weight of the stack, wherein the space between the supports forms a number of fluid channels which serve from one side to supply fluid under and into the stack and are closed on the other side, and on the upper side of which the openings of the continuous heat exchange channels are located.Furthermore, it is preferred that the supports are designed as U-beams lying parallel to one another with upwardly directed U-legs, wherein the weight of the stack acts on the upper ends of the U-legs, and wherein the space between the U-legs forms the horizontally running fluid channels, on the upper side of which the mouths of the continuous heat exchange channels are located, and preferably the U-beams are arranged at a distance from one another via spacer elements, wherein the width of the spacer elements corresponds to the width of the connecting sections of the U-beams.

[0075] For clarity, Figure 5b shows a 3D view of the stack 51 of lattice blocks 70, mounted on the U-beams 61 according to Figure 5a, wherein an embodiment of a throttle arrangement 22 (Figures 2a and b) in the embodiment according to Figures 3b and c is additionally shown. The pressure equalization chamber 58 is shown in dashed lines to provide a view of the arrangement on the sections 59', 59" of the apertured diaphragm 59.

[0076] Figure 6a shows a view of a distributor grid module 53 according to the invention, which, except for the transverse channels 82 provided on its underside 81, is designed identically to the grid module 70 of Figure 4. The identical design corresponding to the grid module 70 allows the distributor grid module 80 to be stacked like the grid modules 70, namely without any gaps and with heat exchange channels 71, which, when stacked, are aligned with those of the other grid modules 70 and, together with them, form continuous heat exchange channels 71*. Thus, the distributor grid module 80, as shown in Figure 3b, can supplement the stack 51 of grid modules 70 in a bottom layer 52, since it has the same properties as the grid modules 70 of the stack 51 with regard to heat storage and heat transfer from and to the fluid flowing through it.

[0077] The transverse channels 84 preferably extend over the entire underside 81 of the distribution grid module 80, with a transverse channel 84' preferably arranged on the outer side 74 of the distribution grid module 80, the outer side wall of which is missing. This allows a distribution grid module 80 positioned adjacent to the outer side 74 to close the transverse channel 84' with its outer side wall 74', whereupon the latter functionally becomes a normal transverse channel 84. This is analogous to the formation of heat-conducting channels 71 by adjacent grooves 71'; see the description of Figure 4.

[0078] Between the transverse channels 84 there are support ribs 83 which form a support surface for the distributor grid module 53, on which the distributor grid module 53 rests.

[0079] Figure 6b shows a 3D view of the stack 51 with a layer 52 of distribution grid modules 53 according to Figure 3b, but only a section corresponding to the dashed area 83, viewed in the direction of arrow 85 in Figure 5a, is shown. This view shows the course of the transverse channels 84 in relation to the U-beams 61: The distribution grid modules 53 rest on the legs 61', 61" of the U-beams 61, whereby heat exchange channels 71 and 71* end on the support surface of the legs 61', 61" and are now connected to the fluid channels 60 via the transverse channels 82. The transverse channels 82 thus ensure that heat exchange channels 71, 71* ending at the location of the legs 61', 61" can be flowed through with fluid in the same way as any of the heat exchange channels 71, 71*.

[0080] This results in a distributor grid module for a layered heat accumulator, with a support surface and a surface and side surfaces and with heat exchange channels 71', 71* running from the support surface to the surface, characterized in that the support surface is designed to support the distributor grid module during operation on U-legs 61', 61", which are arranged parallel to one another and form fluid channels 60, wherein transverse channels 82 are provided in the support surface and can be connected to the fluid channels 60, and wherein the transverse channels 82 are designed such that during operation, with the distributor grid module supported on the U-legs, heat exchange channels 71, 71* ending at the location of the legs 61, 61' can be flowed through with fluid in the same way as any of the heat exchange channels (71, 71*).As mentioned, for ease of manufacture, the transverse channels 84 preferably extend the entire length of the distribution grid module 53, but can also be only long enough to extend sufficiently across the width of the legs 61', 61" or the respective support for the stack 51 to ensure the connection of the relevant heat exchange channels 71 with the fluid channels 60. Preferably, in cross-section, the transverse channels 82 only connect adjacent, juxtaposed heat exchange channels 71a and 71b in order to minimize the load on the structure. The wider the transverse channels 84, the greater the stress in the material of the distribution grid module 53 due to the weight it bears of the grid modules 52 stacked above it. Each heat exchange channel 71, 71* is assigned to only one transverse channel, which allows for an optimal design of the transverse channels 84 together with the heat exchange channels 71, 71*.This results in a distributor grid module in which each heat exchange channel 71, 71* is assigned to a transverse channel 82 in such a way that between each two adjacent transverse channels 82 a support rib 83 with a contact surface is formed by these.

[0081] This results in a method according to which the fluid is preferably passed upstream of the heat-storing solid through distributor grid modules which have heat exchange channels which in turn are aligned with heat exchange channels provided in the solid, wherein aligned heat exchange channels together each form a heat exchange channel passing through this, and wherein the inlet side of the distributor grid modules which is upstream in the discharge flow direction has transverse channels which only connect adjacent rows of heat exchange channels to one another, wherein each heat exchange channel is assigned to a transverse channel in such a way that between each two adjacent transverse channels a support rib is formed by said transverse channels, on which support rib the distributor grid modules are mounted.

[0082] It further follows that the heat accumulator 40 preferably has distributor grid modules which have the same arrangement of heat exchange channels as the grid modules and are arranged without any gaps between the cold fluid chamber and the stack such that their heat exchange channels are aligned with those of the grid modules and thus form a section of the continuous heat exchange channels, and wherein the distributor grid modules have transverse channels on their side facing the cold fluid chamber which connect adjacent rows of the heat exchange channels of the distributor grid modules to one another, each heat exchange channel being assigned to a transverse channel such that between each two adjacent transverse channels a support rib is formed by the latter, on which support rib the distributor grid modules are connected to the cold fluid chamber.Furthermore, a distributor grid module is produced, wherein on an underside of the distributor grid module, transverse channels are provided which connect adjacent rows of the heat exchange channels of the grid modules with each other, and each heat exchange channel is assigned to only one transverse channel, such that between each two adjacent transverse channels, a support rib with a contact surface is formed by this.

[0083] Figure 7 shows a 3D view of a section of a throttle grille module 54 according to the invention, which, with the exception of the heat exchange channels 90, is designed identically to the distributor grille module 53. To reduce the complexity of the figure, the elevations 72 of the grille modules 52 and the distributor grille modules 53 have been omitted. However, the throttle grille modules 54 can be stacked in the same way without gaps. Grooves 90' are provided on the outer sides of the throttle grille module 54, which correspond to one half of a heat exchange channel 90, as is the case with the grooves 71' of the grille modules 52 and the distributor grille modules 53. If two throttle grille modules 54 are positioned next to each other without gaps, two opposing grooves 90' form a heat exchange channel 90.

[0084] The heat exchange channels 90 of the throttle grille module 54 differ from the heat exchange channels 71 of a grille module 52 or a distributor grille module 53 by their diameter - apart from that, they are designed and arranged in the same way as is the case with a grille module 52 or a distributor grille module 53.

[0085] The figure shows that the diameter of a heat exchange channel 90 on the underside 81 of the throttle grille module 54 is smaller than on its top side 91, which corresponds to a narrowing of the heat exchange channel 90, whereby the transition from the smaller to the larger diameter can consist, for example, in a conical step 94. The lower section 92 of the throttle grille module between the steps 94 and the transverse channels 84 thus corresponds to a throttle arrangement 22 (Figure 2a), which throttles the fluid in the same way as the perforated orifice plate 29, with the same effect; see the description of Figures 2a and b, 3b and c, and 5a and b.

[0086] The result is a throttle grid module for a layered heat accumulator, with a contact surface and a surface and side surfaces and with heat exchange channels 71, 71* running from the contact surface to the surface, characterized in that the heat exchange channels 71, 71* have a smaller throttle diameter in a narrowed section starting from the base surface.

[0087] Depending on the design of the heat accumulator in the specific case, the skilled person may provide the throttle arrangement 22 with a perforated orifice plate 29 and a layer of throttle grid modules 54 (see Figure 3b), or alternatively with only a perforated orifice plate (Figure 3b, in which layer 52 contains only distributor grid modules 53), or only with throttle grid modules if, in an arrangement according to Figure 3b, the perforated orifice plate 29 is omitted and layer 52 contains only throttle grid modules). Thus, depending on the design of the heat accumulator, the throttling of the fluid (between 30% and 90% of the total pressure drop) is achieved either entirely by a perforated orifice plate 29 or by throttle grid modules 54, or partially by a perforated orifice plate 29 and partially by throttle grid modules 54.

[0088] It should be noted that the layer 52 of throttle grid modules 54 according to Figure 3b can, in principle, also be arranged at the top of the stack 51 or at any height within the stack 52. However, the position in front of the stack 51 in the discharge flow direction appears particularly favorable, since the influence of the possibly colder outer side of the stack 51, which slightly disrupts the thermocline, is then eliminated (see the description of Figure 2b). This preferably results in a heat storage device in which the throttle arrangement is provided between the connection for the cold fluid supply and the stack.

[0089] This results in a method according to claim 1, wherein the fluid, when discharging the heat accumulator, is passed upstream of the heat-exchanging solid through throttle grid modules which have heat exchange channels which in turn are aligned with heat exchange channels provided in the solid, wherein aligned heat exchange channels together each form a heat exchange channel passing through this, and wherein the heat exchange channels of the throttle grid modules have a constriction designed as a throttle, such that at least part of the throttling takes place through the throttle grid modules.Furthermore, a heat accumulator is produced in which the throttle arrangement comprises throttle grid modules which have the same arrangement of heat exchange channels as the grid modules and are arranged without any gaps between the cold fluid chamber and the stack such that their heat exchange channels are aligned with those of the grid modules and thus form a section of the continuous heat exchange channels, and wherein the heat exchange channels of the throttle grid modules have a constriction designed as a throttle such that at least part of the pressure drop of the fluid of the throttling is caused by the throttle arrangement through the throttle grid modules arranged on the stack. Finally, a throttle grid module is produced for a heat accumulator, wherein the heat exchange channels have a smaller throttle diameter in a constricted section emanating from the base area.This means that the heat exchange channels of the distribution grid modules preferably have a constriction designed as a throttle, such that at least part of the pressure drop of the fluid is caused by the throttle grid modules arranged on the stack. With reference to the perforated orifice plate 29 in a heat accumulator according to the invention, this means that the throttle arrangement has a perforated orifice plate designed such that, during the discharge of the heat accumulator, the pressure drop in the fluid flowing through the perforated orifice plate corresponds at least partially to the pressure drop caused by the throttling.

[0090] In summary, a heat storage device according to the invention has a connection for the supply of cold, heat-transporting fluid and a connection for the discharge of the warm heat-transporting fluid after the absorption of heat, and a heat-storing solid arranged between the connections and having fluid channels, furthermore a cold fluid chamber for the supply of fluid to the stack, wherein the solid is designed as a gap-free stack of lattice modules which have parallel heat exchange channels and are stacked in such a way that the heat exchange channels of successive lattice modules are aligned with one another and aligned heat exchange channels together form a continuous heat exchange channel running through the stack, wherein a throttle arrangement is provided between the connection for the supply and the connection for the discharge of fluid, which throttle arrangement is designed in such a waythat during operation of the heat accumulator, when it is discharged, the pressure drop in the fluid through the throttle arrangement is 30% to 90% of the total pressure drop in the fluid between the connections.

Claims

Patent claims 1. A method for discharging heat from a layered heat accumulator having a cold and a warm side, through which a heat-transporting fluid flows, and a filling of heat-storing solid material lying in the fluid flow and exchanging heat with the fluid, wherein the fluid has a pressure drop between a connection for the supply of cold, heat-transporting fluid and a connection for the discharge of the heat-transporting fluid, which is warm after the absorption of heat, characterized in that the fluid is passed through a throttle arrangement during the discharge flow direction between the connection for the supply and the connection for the discharge and is throttled in this such that the pressure drop due to the throttling is 30% to 90% of the total pressure drop in the fluid between the two connections.

2. The method according to claim 1, wherein the fluid is passed during the discharge of the heat accumulator from the connection for the supply line to the solid and then through separate heat exchange channels arranged in the solid, 3. The method according to claim 1, wherein the fluid is conducted to the solid via a cold fluid chamber having a fluid line arrangement and preferably to heat exchange channels arranged in the solid.

4. The method according to claim 1, wherein the pressure drop in the fluid due to the throttling is more than 40%, preferably more than 50%, particularly preferably more than 60%, most preferably more than 70% or more than 80%.

5. The method according to claim 1, wherein for at least partial throttling the fluid flow is passed through a perforated orifice plate, preferably arranged upstream of the solid, located in the fluid flow and throttling the same.

6. The method according to claim 2, wherein the discharge flow direction in vertically extending heat exchange channels is directed from bottom to top.

7. The method according to claim 3, wherein the fluid to be heated is guided in the fluid line arrangement into a fluid pressure equalization chamber and is at least partially throttled at the outlet thereof.

8. The method according to claim 1, wherein the fluid is passed through a solid formed as a stack of lattice blocks, wherein the lattice blocks have parallel, mutually separate heat exchange channels, preferably with the same cross section and preferably with the same distance from one another, and wherein the lattice blocks are aligned with one another in such a way that the heat exchange channels of lattice blocks lying one behind the other in the flow direction are aligned with one another, so that aligned heat exchange channels together each form a straight, uninterrupted heat exchange channel through the stack, which is separate from the other heat exchange channels.

9. The method according to claim 1, wherein the fluid is passed upstream of the heat-exchanging solid through throttle grid modules which have heat exchange channels which in turn are aligned with heat exchange channels provided in the solid, wherein aligned heat exchange channels together each form a heat exchange channel passing through this, and wherein the heat exchange channels of the throttle grid modules have a constriction designed as a throttle, such that at least part of the throttling takes place through the throttle grid modules.

10. The method according to claim 1, wherein the fluid is passed through distributor grid modules upstream of the heat-storing solid, which have heat exchange channels which in turn are aligned with heat exchange channels provided in the solid, wherein aligned heat exchange channels together each form a heat exchange channel passing through this, and wherein the inlet side of the distributor grid modules which is upstream in the discharge flow direction has transverse channels which only connect adjacent rows of heat exchange channels to one another, each heat exchange channel being assigned to a transverse channel in such a way that between each two adjacent transverse channels a support rib is formed by the latter, on which support rib the distributor grid modules are mounted.

11. The method according to claim 10, wherein the heat exchange channels of the distributor grid modules have a constriction designed as a throttle such that at least part of the throttling takes place through the distributor grid modules.

12. The method according to claim 1 or 2, wherein the fluid is passed through heat exchange channels arranged in the solid, which have the same cross-section and the same length and are arranged separately from one another at the same distance from one another.

13. Layered heat storage device for carrying out the method according to claim 1, with a connection for the supply of cold, heat-transporting fluid and a connection for the discharge of the heat-transporting fluid, which is warm after absorbing heat, with a heat-storing solid arranged between the connections and having fluid channels, and with a cold fluid chamber for the supply of fluid to the stack, characterized in that the solid is designed as a gap-free stack of lattice modules which have parallel heat exchange channels and are stacked in such a way that the heat exchange channels of successive lattice modules are aligned with one another and aligned heat exchange channels together form a continuous heat exchange channel running through the stack, wherein a throttle arrangement is provided between the connection for the supply and the connection for the discharge of fluid, which throttle arrangement is designed in such a waythat during operation of the heat accumulator, when it is discharged, the pressure drop in the fluid through the throttle arrangement is 30% to 90% of the total pressure drop in the fluid between the connections.

14. Heat accumulator according to claim 13, wherein the throttle arrangement is provided between the connection for the supply of cold fluid and the stack.

15. Heat accumulator according to claim 13, wherein the throttle arrangement is designed such that the pressure drop in the fluid due to the throttling is more than 40%, preferably more than 50%, particularly preferably more than 60%, very preferably more than 70% or more than 80%.

16. Heat accumulator according to claim 13, wherein the throttle arrangement comprises a perforated diaphragm which is designed such that during the discharge of the heat accumulator the Pressure drop in the fluid flowing through the orifice plate corresponds at least partially to the pressure drop caused by the throttling.

17. Heat storage device according to claim 13, wherein the heat exchange channels of the stack run vertically and the connection for the supply of cold, heat-transporting fluid is arranged below the stack.

18. Heat storage device according to claim 13, wherein the throttle arrangement is arranged below the stack.

19. Heat accumulator according to claim 13, wherein the cold fluid chamber comprises a number of supports arranged below the stack and running side by side, which supports the weight of the stack, the space between the supports forming a number of fluid channels which serve from one side to supply fluid under and into the stack and are closed on their other side, and at the top of which the mouths of the continuous heat exchange channels are located.

20. Heat storage device according to claim 19, wherein the supports are designed as parallel U-beams with upwardly directed U-legs, wherein the weight of the stack acts on the upper ends of the U-legs, and wherein the space between the U-legs forms the horizontally running fluid channels, on the upper side of which the mouths of the continuous heat exchange channels are located and preferably the U-beams are arranged at a distance from one another via spacer elements, wherein the width of the spacer elements corresponds to the width of the connecting sections of the U-beams.

21. Heat accumulator according to claim 19, wherein the throttle arrangement comprises a perforated diaphragm which is arranged on the side of the fluid supply line under the stack at the end face of the fluid channels and operatively covers the inlet to the fluid channels.

22. Heat accumulator according to claim 13, wherein a pressure equalization chamber is provided between the connection for the supply of fluid and the throttle arrangement.

23. Heat accumulator according to claim 13, wherein the throttle arrangement comprises throttle grid modules which have the same arrangement of heat exchange channels as the grid modules and are arranged without any gaps between the cold fluid chamber and the stack such that their heat exchange channels are aligned with those of the grid modules and thus form a section of the continuous heat exchange channels, and wherein the heat exchange channels of the throttle grid modules have a constriction designed as a throttle such that at least part of the pressure drop of the fluid of the throttling is caused by the throttle grid modules arranged on the stack.

24. Heat accumulator according to claim 13, wherein the distributor grid modules have the same arrangement of heat exchange channels as the grid modules and are arranged without any gaps between the cold fluid chamber and the stack such that their heat exchange channels are aligned with those of the grid modules and thus form a section of the continuous heat exchange channels, and wherein the distributor grid modules have, on their side facing the cold fluid chamber, transverse channels which connect adjacent rows of the heat exchange channels of the distributor grid modules to one another, each heat exchange channel being assigned to a transverse channel such that between each two adjacent transverse channels a support rib is formed by the latter, on which support rib the distributor grid modules are connected to the cold fluid chamber.

25. Heat accumulator according to claim 23, wherein the heat exchange channels of the distributor grid modules have a constriction designed as a throttle, such that at least part of the pressure drop of the fluid of the throttling is caused by the throttle grid modules arranged on the stack.

26. A stackable lattice module for a layered heat accumulator according to claim 11, having a support surface and a surface and side surfaces and having heat exchange channels extending from the support surface to the surface, characterized in that these are arranged parallel and equidistant from one another, are round in cross section, have an effective diameter of 50 mm or less, and that the distance between adjacent heat exchange channels is 70 mm or less. U. Lattice building block according to claim 26, wherein the diameter of the heat exchange channels is 25 mm or less, or 20 mm or less, preferably 15 mm or less, most preferably 10 mm or less.

28. A lattice brick according to claim 26, wherein the distance between adjacent heat exchange channels is 50 mm or less, more preferably 30 mm or less, further preferably 10 mm or less, at least three times the average grain diameter of the material of the lattice brick.

29. A throttle grid module according to claim 26, wherein the heat exchange channels have a smaller throttle diameter in a narrowed section extending from the base area.

30. Distributor grid module according to claim 26, wherein on an underside of the distributor grid module, transverse channels are provided which extend therein and connect adjacent rows of the heat exchange channels of the grid modules with one another, and each heat exchange channel is assigned to a transverse channel in such a way that between each two adjacent transverse channels, a support rib with a contact surface is formed by the transverse channels.

31. A distributor grid module for a layered heat accumulator, having a support surface and a surface and side surfaces, and having heat exchange channels (71', 71*) extending from the support surface to the surface, characterized in that the support surface is designed to support the distributor grid module during operation on U-shaped legs (61', 61") arranged parallel to one another, which form fluid channels (60), wherein transverse channels (82) are provided in the support surface and can be connected to the fluid channels (60), and wherein the transverse channels (82) are designed such that during operation, with the distributor grid module supported on the U-shaped legs, heat exchange channels (71, 71*) ending at the location of the legs (61, 61') can be flowed through by fluid in the same way as any of the heat exchange channels (71, 71*).

32. Distributor grid module according to claim 31, wherein each heat exchange channel (71, 71*) is associated with a transverse channel (82) such that between each two adjacent Transverse channels (82) through which a support rib (83) with a contact surface is formed.

33. Throttle grid module for a layered heat accumulator, with a contact surface and a surface and side surfaces and with heat exchange channels (71, 71*) running from the contact surface to the surface, characterized in that the heat exchange channels (71, 71*) have a smaller throttle diameter in a narrowed section starting from the base surface.