METHOD AND DEVICE FOR FILLING, COMPACTING AND EVACUATING A VACUUM ACCUMULATOR

Abstract

A method for filling, compacting, and evacuating a vacuum storage tank (2) for storing hot water, wherein the vacuum storage tank comprises at least an inner tank (100) for holding water, an outer tank (200) surrounding the inner tank (100), a connection flange (110) connected to the inner tank (100) for receiving and securing a closure body, and an insulating unit (201) between the inner tank (100) and the outer tank (200), wherein the insulating unit (201) is filled with an insulating material and evacuated, comprising the following steps: a) Initial weighing of the vacuum storage tank (2); b) Initial evacuation of the insulating unit (201); c) Initial filling of the insulating unit (201) with an insulating material; d) Second weighing of the vacuum storage tank (2); e) Initial compaction of the insulating material in the insulating unit (201); f) Second evacuation of the insulating unit (201);g) Determining the filling status in the insulation unit, g1) if filling status < target value, then proceed to process step h); or g2) if filling status = target value, then proceed to process step l); h) Second filling of the insulation unit (201) with insulating material; i) Third weighing of the vacuum storage unit (2); j) Second compaction of the insulating material in the insulation unit (201); k) Third evacuation of the insulation unit (201); l) Closing of the insulation unit (201) of the vacuum storage unit (2) or of the filling and evacuation pipe of the vacuum storage unit (2);

Description

[0001] The invention relates to a method for filling, compressing and evacuating a vacuum storage tank for storing hot water, having the features of the preamble of claim 1 and the device for carrying out the method according to claim 7.

[0002] Vacuum storage tanks, such as hot water tanks, are known for generating and storing hot water, primarily used in households. When hot water is drawn from the vacuum storage tank, cold water automatically flows into the storage tank, which is then reheated. Hot water tanks are available in various sizes and storage volumes. Depending on the size and intended use of the hot water tank, the mounting and installation of the hot water tank also vary. For example, there are hot water tanks that are hung or attached to a wall.

[0003] Typically, wall-mounted hot water tanks have a cold water inlet, a hot water outlet, a heating element, a temperature sensor, an impressed current anode or an MgO anode, and a safety temperature sensor at the bottom, which lead into the interior of the storage tank. The disadvantage is that these components and their corresponding openings each form a heat transfer path from the interior of the tank to the outside. Especially in the case of vacuum-insulated hot water tanks, there is a high need for continuous optimization to reduce heat transfer from the hot water tank to the outside.

[0004] DE 102017209782 A1 discloses a method for thermally insulating an evacuable container. EP 3995772 A1 discloses a method for crimping the tubular element for filling and evacuation, as well as a crimping tool for carrying out the method.

[0005] A storage tank, especially one made of steel, has the disadvantage that a kind of funnel forms in the middle of the storage tank during the suction phase of the insulation material. The insulation material adheres to the walls of the storage tank, and there is then insufficient insulation material in the reservoir, creating an air hole. As a result, the vacuum pump sucks in air instead of insulation material. The resulting problem is an insufficient amount of insulation material and inhomogeneous thermal insulation in the vacuum storage tank. At the same time, this also poses the risk that the material adhering to the walls of the storage tank will suddenly fall from the walls into the middle of the storage tank, causing blockages in the device's lines. A vibrator that sets the storage tank in motion can remedy this.This sets the storage container in motion, shaking up the insulation material inside. The disadvantages of this are the acquisition and operating costs of the vibrator, and at the same time, the vibrations can have a negative impact on the weld points of the storage container and the device.

[0006] Therefore, the object of the invention is to provide a method that features optimized process steps, thus allowing the introduction of the insulation material to be carried out more homogeneously and efficiently. In addition to the uniform introduction of the insulation material, complete filling of the vacuum storage unit with the insulation material must be ensured. At the same time, the costs of thermal insulation should be kept low, the process for implementation and the associated number of process steps should be minimized, and the device should be optimized for this purpose.

[0007] This object is achieved by a method having the features of claim 1 and by the device for filling, compressing, and evacuating a vacuum storage device having the features of claim 7. Advantageous embodiments of the invention are specified in the subclaims.

[0008] With hot water tanks, it is important that the temperature of the water can be maintained for as long as possible without reheating. To achieve this goal, very good insulation is required all around the tank. For this purpose, a vacuum tank is used, which contains a water tank. An insulating unit between the outer and inner tanks is evacuated and filled with a special insulating powder, in particular fumed silica. The insulation thickness is dimensioned based on the required technical parameters. Insulation with insulating powder is not possible in the lower section of the hot water tank. There is an opening there into which a heating element is inserted, where the connections for the inlet and outlet of the hot water tank and, if applicable, other components are located. Therefore, materials with low thermal conductivity are used in the lower section of the hot water tank.

[0009] According to the invention, the method relates to a vacuum storage device which consists of an inner container and an outer container which surrounds the inner container. A gap is formed between the inner container and the outer container, which gap is used as an insulating layer or to accommodate an insulating medium. An insulating material is introduced into this insulating unit and a vacuum is created. This results in very good insulation of the inner container. Once the manufacturing steps for the vacuum storage device have been completed, an evacuation and filling pipe, which is made in particular of copper, remains on the outer container. A subsequent cover conceals the remaining or separated evacuation and filling pipe. This evacuation and filling pipe forms the connection between the device for filling, compressing and evacuating and the vacuum storage device. The gap orThe insulation unit between the inner container and the outer container is filled with insulating material, compacted, and then evacuated. This compaction ensures that the insulating material is evenly distributed, creating a homogeneous insulation around the inner container.

[0010] The filling, compacting, and evacuating process involves the following steps: The first step involves determining the actual weight of the vacuum storage unit (initial weighing). Due to manufacturing tolerances, the weight varies slightly from vacuum storage unit to vacuum storage unit. This information is crucial for the process, allowing the exact amount of insulation material added to be determined in the intermediate step and also at the end.

[0011] The first evacuation is then performed. The vacuum pump is operated at high power, specifically > 95% of its capacity, and maintains this power for a few minutes, particularly between 2 and 4 minutes. The next step is the first filling process. Filling occurs via pressure equalization. The filling line valve is opened, and the insulation material is pumped via the filling and evacuation line into the gap in the insulation unit, between the inner and outer vessels of the vacuum storage tank.

[0012] The pressure in the insulation unit is < 100 mbar, preferably < 50 mbar, but especially preferably < 5 mbar. The filling status is determined by subsequent weighing (second weighing) and determining the weight of the vacuum storage tank filled up to that point. This determines the possible remaining amount of insulation material.

[0013] In order to be able to add additional insulation material to the insulation unit and at the same time achieve homogeneous insulation, the insulation material is compressed in the vacuum storage unit.

[0014] The subsequent second evacuation differs from the first evacuation. While the first evacuation is designed to create a vacuum quickly and easily, allowing the vacuum pump to operate at high power, the vacuum pump must be precisely regulated during the second evacuation. This poses the problem that the insulation material already contained in the insulation unit is drawn out again, potentially clogging the vacuum pump and the lines.

[0015] In the next step, the insulation unit could be refilled. At this point, or at another point in the process, a decision is made about further filling. The first weighing determines the weight of the empty vacuum storage unit; after the second weighing, the weight of the vacuum storage unit after the first filling is known. By calculating the difference between the two weights, the actual amount of insulation material added is determined. This difference is compared with a predetermined target value. If the difference corresponds to the target value, no further filling is necessary. If the difference is smaller than the target value, further filling is necessary to achieve a beneficial filling level of approximately 100%.

[0016] If the vacuum reservoir is refilled, it is also weighed after refilling to determine its status (third weighing). After the subsequent and renewed compaction (second compaction) of the insulation material in the insulation unit, the final evacuation is performed. The vacuum pump valve and the vacuum suction line valve are opened, the vacuum pump is regulated, and a pressure of < 100 mbar, preferably < 50 mbar, but especially preferably < 5 mbar, is generated in the vacuum reservoir. The vacuum reservoir or the filling and evacuation pipe of the vacuum reservoir can now be closed and disconnected.

[0017] An optional final weighing (fourth weighing) checks the weight and the correct procedure for the last time.

[0018] Furthermore, the invention provides a device for filling, compressing, and evacuating a vacuum reservoir, with which the method according to the invention is carried out. The device consists of a storage container, a vacuum pump, lines, and, in the advantageous embodiment, a total of four valves. The storage container holds the insulating material in powder form, and the flow of the insulating material is directed toward the vacuum reservoir.

[0019] To avoid the aforementioned problem of air being sucked in instead of the insulation material, the device according to the invention uses a storage container made of plastic, or at least partially made of plastic, or coated with plastic. By replacing the steel storage container with one made of plastic, or one with a plastic coating, the insulation material no longer clings to the walls of the storage container, creating an air pocket.

[0020] The advantageous arrangement of the valves ensures efficient filling, compacting, and evacuating. The filling line valve and the vacuum suction line valve are preferably arranged in parallel. The vacuum suction line and the filling line flow into the filling and evacuation line, with the filling and evacuation line connected to the vacuum reservoir. A scale on the device ensures that the vacuum reservoir is weighed.

[0021] Using this weighing method, it is possible to determine the filling status and thus the remaining amount of insulation material to be filled and to introduce this into the insulation unit of the vacuum storage unit in the optional next filling step.

[0022] The hot water tank preferably has a capacity of up to 300 liters, particularly preferably between approximately 5 and approximately 150 liters.

[0023] Advantages and embodiments of the invention are explained in more detail below with reference to the drawings: Figures: Fig. 1 shows a schematic representation of the device for filling, compressing and evacuating a vacuum storage tank Fig. 2 a sectional view of a vacuum storage tank

[0024] The process for filling, compressing and evacuating a vacuum storage tank for storing hot water is described in Fig. 1 device shown for filling, compacting and evacuating 1 The preferred valve arrangement is discussed. The insulation material is located in the storage tank. 3. The flow of the insulation material is from the storage tank 3 towards vacuum storage 2. Via a reservoir valve 3.1 and the reservoir line 3.2 the insulation material enters the filling line 7and then via filling line valve 7.1 and the filling and evacuation line 8 into the insulation unit of the vacuum storage 2. The vacuum pump 4 is regulated according to needs and depending on the process step.

[0025] The vacuum is created via the vacuum pump valve 4.1 controlled, which is located in the vacuum pump line 4.2 Parallel to the filling line 7, is the vacuum suction line 6 arranged in which the vacuum suction line valve 6.1 Both the filling line 7 as well as the vacuum suction line 6 flow into the filling and evacuation line 8. Parallel to vacuum suction line valve 6.1 is the filling line valve 7.1 in the filling line 7 arranged.

[0026] The procedure starts with a) weighing and determining the actual weight of the vacuum storage2. After weighing, the first b) evacuation by the vacuum pump 4 and by opening the vacuum pump valve 4.1 carried out. The vacuum pump 4 is operated at high power, especially > 95% of the capacity, and maintains this power for a few minutes, especially between 2 and 4 minutes. In the next step, c), the first filling begins. The filling line valve 7.1 is opened and the insulation material is taken from the storage container 3 via the filling and evacuation line 8 into the gap of the insulation unit 201 the vacuum storage 2 The pressure in the insulation unit is less than 100 mbar, preferably less than 50 mbar, but especially preferably less than 5 mbar.

[0027] The weight of the vacuum storage unit is determined via the subsequent d) weighing 2In order to be able to introduce additional insulation material into the gap and at the same time achieve a homogeneous insulation, e) the insulation material is stored in the vacuum storage 2 condensed.

[0028] The subsequent f) second evacuation differs from the a) first evacuation. While in the a) first evacuation a vacuum is created easily and quickly and the vacuum pump 4 can therefore be operated with high performance, the vacuum pump is 4 f) the second evacuation. The problem here is that the insulation material, which is already in the insulation unit 201 is pulled out again and thus the vacuum pump 4 and can clog the pipes.

[0029] In the next step (g), which can also occur at a different point in the process, a decision is made regarding further filling. The first weighing determines the weight of the empty vacuum storage tank; after the second (or subsequent) weighing, the weight of the vacuum storage tank after the first (or subsequent) filling is known. By calculating the difference between the two weights, the actual amount of insulation material added is determined in weight.

[0030] This means that a difference is calculated between the nth weighing (n = 1, 2, 3, ...) and the first weighing. This difference is compared with a specified target value. If the difference corresponds to the target value, no further filling is necessary, and the process can be completed in the next step. If the difference is smaller than the target value, further filling is necessary.

[0031] In very rare cases, overfilling can occur, in which case it is advantageous to report this to the production staff via a signal.

[0032] In the advantageous embodiment of the method, the first filling is slightly below full; according to one concept of the invention, the container is filled to approximately 90% as a guideline. The remaining amount is then added during the second filling.

[0033] The decision process as to whether further filling is necessary can be carried out once or several times in the procedure.

[0034] If the vacuum reservoir is filled again (h), the remaining required amount of insulation material is introduced into the insulation unit or, if no further filling is required, the process proceeds directly to step I). After filling, the weight of the vacuum reservoir is determined again and the correct amount introduced is checked. After the subsequent j) compaction of the insulation material in the gap of the insulation unit 201, k) the final evacuation is carried out. The vacuum suction line valve 6.1 opened, the vacuum pump 4 regulated and generates a pressure of less than 100 mbar, preferably less than 50 mbar, but especially preferably less than 5 mbar. k) The vacuum storage 2 or the filling line of the vacuum storage can now be closed.

[0035] An optional final weighing checks the weight and the correct procedure for the last time.

[0036] In Fig. 2 is a vacuum storage 2 in a sectional view. The outer container 200 surrounds the inner container 100. Between the outer container 200 and the inner container 100 there is an isolation unit 201, which is filled with insulating material and in which a vacuum is created. The inner container 100 consists of a lid part 120, a jacket part 130 and a base part 140 formed. On the inner container 100, especially on the bottom part 140, is a connecting flange 110 welded. The floor 210 of the outer container 200 is designed in two parts and consists of an inner and an outer ring. The insulation unit 201 consists of a gap which is filled with an insulating material or insulating medium and then evacuated. Consequently, the insulation unit insulates 201the inner container 100. The outer container 200 Floor 210, a lid 220 and a housing 230. A locking body is inserted into the opening 113 introduced and on the connecting flange 110 attached. List of reference symbols

[0037] 1 device 2 Vacuum storage 3 storage container 3.1 Reservoir valve 3.2 Reservoir line 4 vacuum pump 4.1 Vacuum pump valve 4.2 Vacuum pump line 5 connecting line 6 Vacuum suction line 6.1 Vacuum suction line valve 7 Filling line 7.1 Filling line valve 8 Filling and evacuation line 100 inner container 110 connecting flange 113 opening 120 Cover part 130 Coat part 140 Bottom part 200 Outer container 201 insulation unit 210Floor 220 Lid 230 Housing

Claims

1. A method for filling, compressing and evacuating a vacuum storage device (2) for storing hot water, wherein the vacuum storage device (2) consists at least of - an inner container (100), - an outer container (200) which surrounds the inner container (100), - a connecting flange (110) connected to the inner container (100) for receiving and fastening a closure body and - an insulating unit (201) between the inner container (100) and the outer container (200), wherein the insulating unit (201) is filled with an insulating material and a vacuum is generated in the insulating unit (201), comprising the following steps: a) First weighing of the vacuum storage device (2); b) First evacuation of the insulating unit (201); c) First filling of the insulating unit (201) with an insulating material; d) Second weighing of the vacuum storage device (2); e) First compression of the insulating material in the insulating unit (201); (f) Second evacuation of the isolation unit (201);g) Determining the filling status in the insulation unit (201), g1) if the filling status < the target value, then continue with process step h); or g2) if the filling status = the target value, then continue with process step I); h) Second filling of the insulation unit (201) with an insulating material; i) Third weighing of the vacuum accumulator (2); j) Second compacting of the insulating material in the insulation unit (201); k) Third evacuation of the insulation unit (201); l) Closing the insulation unit (201) of the vacuum accumulator (2) or the filling and evacuation pipe of the vacuum accumulator (2); 2. Method for filling, compressing and evacuating a vacuum storage device (2) according to claim 1, characterized in that The filling status is determined by weighing and a difference value is calculated which results from the first weighing and a further weighing.

3. Method for filling, compressing and evacuating a vacuum storage device (2) according to claim 1 and 2, characterized in thatthe evacuation is carried out by controlling the vacuum pump (4), in which the performance of the vacuum pump (4) is adapted to the process step.

4. Method for filling, compressing and evacuating a vacuum storage device (2) according to claims 1 to 3, characterized in that the insulation unit (201) is brought to a pressure of < 100 mbar, preferably < 50 mbar, but particularly preferably < 5 mbar.

5. Method for filling, compressing and evacuating a vacuum storage device (2) according to claims 1 to 4, characterized in that the procedure is applied once or several times in succession.

6. Method for filling, compressing and evacuating a vacuum storage device (2) according to claims 1 to 5, characterized in that fumed silica is used as the insulating material of the insulating unit (201).

7. Device (1) for filling, compressing and evacuating a vacuum accumulator (2) in order to carry out the method according to claim 1, at least comprising: - a storage container (3) for holding insulating material; - a storage container valve (3.1) in the storage container line (3.2); - a vacuum pump (4) for generating a vacuum in the vacuum accumulator (2); - a vacuum pump valve (4.1) in the vacuum pump line (4.2); - a connecting line (5); - a vacuum suction line valve (6.1) in the vacuum suction line (6); - a filling line valve (7.1) in the filling line (7); - a filling and evacuation line (8); 8. Device (1) for filling, compressing and evacuating a vacuum storage device (2) according to claim 7, characterized in that the storage container (3) consists at least partially of plastic or has a plastic coating.

9. Device (1) for filling, compressing and evacuating a vacuum storage device (2) according to claim 7, characterized in thatFilling line valve (7.1) and the vacuum suction line valve (6.1) are arranged in parallel.

10. Device (1) for filling, compressing and evacuating a vacuum storage device (2) according to claim 7, characterized in that the vacuum suction line (6) and the filling line (7) open into the filling and evacuation line (8), wherein the filling and evacuation line (8) is connected to the vacuum storage device (2).

11. Device (1) for filling, compressing and evacuating a vacuum storage device (2) according to claim 7, characterized in that the storage tank line (3.2) and the vacuum pump line (4.2) flow into the connecting line (5).

12. Device (1) for filling, compressing and evacuating a vacuum storage device (2) according to claim 7, characterized in that the device (1) includes a scale that weighs the vacuum reservoir (2) and determines the filling status.