Low temperature memory system

Abstract

The invention relates to a cryogenic storage system, comprising a cryogenic vessel for storing hydrogen, having an inner tank (1) and an outer vessel (2), wherein at least one cryogenic pump (21) is arranged in the inner tank (1) of the cryogenic vessel, wherein the cryogenic pump (21) delivers liquid and / or gaseous hydrogen at a pressure higher than the pressure in the inner tank (1) to a consumer (5) in one or more stages via an extraction line (27), wherein the inner tank (1) can be filled via a filling connection (14), wherein the filling takes place at least section-wise via the extraction line (27), wherein the filling of the inner tank (1) is effected by a spring-loaded non-return valve (25) or a changeover valve (26).

Description

Technical Field

[0001] The present invention relates to a cryogenic storage system comprising a cryogenic container for storing hydrogen, particularly as a mobile cryogenic storage system for storing hydrogen for powering vehicles. Background Technology

[0002] It is known to use mobile cryogenic storage systems to carry the hydrogen needed for propulsion in vehicles.

[0003] To extract from the tank, the pressure inside the tank is increased, which is typically achieved by heating the contents of the container, or by external energy, or by a heat exchanger arranged in the inner tank of the storage container through which the evaporated gas flows.

[0004] Extraction devices are described in utility models AT 009 291U1 and AT 010 015U1, which partially overcome the disadvantages associated with conventional devices by means of gaseous gas being returned from a pump and blown into a storage container, or into a gas space, or into a liquid near the bottom.

[0005] Alternatively, fluid transport can be achieved by a fluid pump having a linear drive and a regulating device via a downstream heat exchanger, as is known from document US2012317995A1.

[0006] However, the known solutions have some drawbacks, such as:

[0007] - For known solutions, the operating pressure in the inner tank must be greater than the supply pressure for the consumer. This reduces the available storage capacity of the inner tank because the density of the cryogenic liquid gas decreases with increasing pressure.

[0008] - The higher normal operating pressure in the inner tank reduces the pressure difference until the evaporator valve (boil-off) responds, meaning the pressure build-up time is reduced.

[0009] - Pressure formation in the inner tank via a passive system (closed inner tank heat exchanger) is only feasible if it is simultaneously extracted for the consumer. This means that in practice, after filling (which is carried out at a pressure lower than the operating pressure), only a very small amount of gas can initially be supplied to the consumer.

[0010] - In the alternative, the so-called active system, a high-powered fan is used outside the system, and warm hydrogen is delivered to the inner tank at a low pressure differential via pipe connections, thereby increasing its pressure level, independent of simultaneous extraction by the consumer. The fan and the required high-voltage electronics require power consumption in the kilowatt range. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to provide a cryogenic storage system of the above type, which can reduce at least some of the problems, and in particular to provide a cryogenic storage system including a cryogenic vessel for storing hydrogen, which achieves favorable operating pressure in the inner tank and reliable extraction of the medium from the inner tank, as well as reliable filling of the inner tank in a cost-effective manner.

[0012] The solution to the aforementioned technical problem is achieved through a cryogenic storage system comprising a cryogenic container for storing hydrogen, the cryogenic container having an inner tank and an outer tank, wherein at least one cryogenic pump is arranged in the inner tank of the cryogenic container, wherein the cryogenic pump delivers liquid and / or gaseous hydrogen to a consumer in one or more stages through an extraction line at a pressure higher than the pressure in the inner tank, wherein the inner tank can be filled through a filling port, wherein filling is at least partially performed through the extraction line, and wherein filling of the inner tank is achieved by a spring-loaded check valve or a reversing valve.

[0013] According to the invention, the cryogenic storage system has at least one cryogenic pump within the inner tank of the cryogenic container. Liquid and / or gaseous hydrogen can be cryogenically extracted from the inner tank by the cryogenic pump and preferably supplied to a heat exchanger, which heats the hydrogen and then further delivers it to a consumer. Here, the delivery to the consumer can be carried out at a pressure higher than the pressure within the inner tank of the cryogenic storage system.

[0014] The cryogenic pump is located inside the inner tank of the cryogenic vessel, specifically in the cryogenic region where the cryogenic storage system operates normally. Therefore, the cryogenic pump is completely surrounded by cryogenic fluid during normal operation. The drive unit of the cryogenic pump is configured to operate at cryogenic temperatures.

[0015] Refilling of this device is performed via a refilling interface, wherein, according to the invention, refilling is at least partially performed via an extraction line, i.e., at least partially performed via the same line through which hydrogen can also be extracted from the inner tank by a cryogenic pump. According to the invention, refilling is performed via a spring-loaded check valve or a reversing valve in the inner tank. Thus, the cryogenic storage system can be refilled via the extraction line, but bypassing the cryogenic pump in the inner tank.

[0016] Using a cryogenic pump in the inner tank offers several advantages: it allows for minimized operating pressure within the inner tank, which can be lower than the minimum possible supply pressure of the consumer. Lower operating pressure in the inner tank enables longer pressure build-up times or lower design pressures, and consequently, lower wall thicknesses, allowing for lighter inner tanks or more complex storage container geometries. Backgas losses during liquid gas filling are reduced by lower inner tank pressures. Improved thermodynamic conditions within the inner tank enable higher filling rates. Changes in head (delivery pressure) or delivery rate are accelerated or simplified. The energy consumption for operating a cryogenic pump, which is fully exposed to the temperature of the cryogenic fluid, is significantly lower than that of an active system with a fan, pump, or compressor that operates substantially at ambient temperature for driving and / or compression. When configured appropriately, liquids and / or gases can be selectively delivered. This achieves coordination between extracting mass flow rate and reducing pressure through volumetric work.

[0017] The improved design of the present invention is given in the description and accompanying drawings.

[0018] According to one embodiment, a spring-loaded check valve is arranged in an inlet pipe leading into the inner tank, the inlet pipe branching off from a pressure pipe leading to a medium delivered by a cryogenic pump and an extraction pipe.

[0019] An inlet line to the inner tank is a line that leads into the inner tank of the cryogenic storage system, preferably near the top of the inner tank, and / or into an area of ​​the inner tank that typically contains gaseous hydrogen.

[0020] According to another embodiment, a reversing valve is arranged in the pressure line of the cryogenic pump that discharges the transported medium, wherein the pressure line that discharges the transported medium transitions at the reversing valve into the inlet line that enters the inner tank, such that at the reversing valve, depending on the state of the reversing valve, it either opens to the inlet of the pressure line and closes to the inlet of the inlet, or closes to the inlet of the pressure line and opens to the inlet of the inlet.

[0021] Preferably, the directional valve has an inlet to the extraction line, which opens both when the inlet to the pressure line is opened and when the inlet to the inlet is opened. The directional valve thus has three inlets: to the extraction line, to the inlet line, and to the pressure line of the cryogenic pump.

[0022] Preferably, the reversing valve has an integrated suspension body, wherein the weight of the suspension body holds it in the lower position during filling, allowing the inlet line to be released to fill the inner tank. During the start-up of the cryogenic pump, the suspension body is lifted by the delivery flow, causing it to close the inlet line to the inner tank and the delivery flow to be pumped only to the consumer.

[0023] Preferably, the cryogenic pump is designed as a linear pump that delivers fluid from both sides.

[0024] Particularly preferably, the left and / or right delivery flow of the linear pump is designed to selectively deliver gaseous or liquid hydrogen, preferably via a shut-off valve near the pump for switching from LH2 (liquid hydrogen) to GH2 (gaseous hydrogen).

[0025] The cryogenic vessel is preferably configured to return a portion of the heated hydrogen stream, i.e., a portion of the hydrogen extracted after the heat exchanger, to the inner tank via a gas return line to increase the pressure in the inner tank and preferably maintain it at a minimum pressure. A shut-off valve for returning gas to the inner tank is preferably arranged in the gas return line.

[0026] Preferably, a pressure regulator, preferably equipped with a downstream pressure relief valve, is installed in the gas return line used to guide the gas back to the inner tank. This limits the pressure used to guide the gas back to the inner tank.

[0027] Preferably, a buffer container for warming hydrogen is installed between the cryogenic pump and the consumer. This can compensate for possible fluctuations in the delivery power of the cryogenic pump. Attached Figure Description

[0028] The present invention will now be described with reference to the accompanying drawings.

[0029] Figure 1 A schematic diagram of a cryogenic storage system according to the present invention is shown.

[0030] Figure 2 Shown in another variant design according to Figure 1 A schematic diagram of a portion of the cryogenic storage system according to the present invention.

[0031] Figure 3 Shown in another variant design according to Figure 1 A schematic diagram of a portion of the cryogenic storage system according to the present invention.

[0032] Figure 4 A schematic diagram of a cryogenic storage system according to the invention is shown in another variant design.

[0033] Figure 5 A schematic diagram of a cryogenic storage system according to the invention is shown in another variant design.

[0034] Figure 6 A schematic diagram of a cryogenic storage system according to the invention is shown in another variant design.

[0035] Figure 7 Showing according to Figure 6 A schematic diagram of the reversing valve of the cryogenic storage system according to the present invention in the first state.

[0036] Figure 8 Showing according to Figure 6A schematic diagram of the reversing valve of the cryogenic storage system according to the present invention in the second state. Detailed Implementation

[0037] exist Figure 1 The image shows a cryogenic storage system according to the present invention, which includes a cryogenic container comprising an inner container 1 and an outer container 2, together with an isolation space serving as a gap between the inner container 1 and the outer container 2.

[0038] The cryogenic storage system can deliver cryogenic liquid from the inner tank 1 to the consumer 5 through the power-controlled booster cryogenic pump 21 and the pressure line 22 of the cryogenic pump. The pressure line 22 is then connected to the extraction line 27 and the supply line 4 is connected at the line connection 3.

[0039] The cryogenic pump 21 is completely surrounded by cryogenic fluid, meaning that the drive unit of the pump 21 also operates at cryogenic temperatures, thereby achieving low power consumption for cold gas compression.

[0040] Furthermore, gas can flow from the inner tank 1 into the extraction line 27 by opening the GH2 tank valve 15 and / or liquid can flow from the inner tank 1 into the extraction line 27 by opening the LH2 tank valve 16. Here, gas can be extracted from the inner tank 1 through the combined safety and gas extraction line 18. A check valve 17 for gas extraction can be installed after the GH2 tank valve 15. From the combined safety and gas extraction line 18, gas can be discharged externally through the pressure-reducing safety valve 19.

[0041] After being drawn from the inner tank 1, particularly after the cryogenic pump 21 and tank valves 15 and 16, the cryogenic fluid, especially liquid hydrogen, is guided through the heat exchanger 7, where it is completely transferred to the gas phase via a heat input preferably through the cooling water 11 of the consumer 5, simultaneously fully heating the consumer 5. The cryogenic pump 21 delivers hydrogen to the consumer 5 at a pressure higher than that in the inner tank 1 when needed. By extracting fuel from the cryogenic storage system, the pressure and amount of fuel in the inner tank 1 are reduced.

[0042] To compensate for potential power fluctuations in the cryogenic pump 21, a buffer container 8 for warming hydrogen can be additionally arranged between the pump 21 and the consumer 5, particularly in the supply line 4. A shut-off valve 12 for supplying H2 to the consumer 5 can be arranged in the supply line 4 before the consumer 5.

[0043] The cryogenic storage system can be filled via filling interface 14. Filling can be carried out in sections via extraction line 27 and inlet line 20 into the inner tank 1, preferably into the area of ​​gaseous hydrogen in the inner tank 1.

[0044] like Figure 1-5As shown, a spring-loaded check valve 25 can be arranged in the inlet pipe 20 that enters the inner tank 1. The inlet pipe 20 is formed by branching pipes that lead out the pressure pipe 22 and the extraction pipe 27 of the medium delivered by the cryogenic pump 21.

[0045] Then, filling can be carried out through the extraction line 27, the spring-loaded check valve 25, and the inlet line 20 into the inner tank 1.

[0046] If it is necessary to increase or maintain the pressure in the inner tank 1 of the cryogenic storage system, gas can be returned to the inner tank 1 through valve 13 in the gas return line 6, which branches off from the extraction line 27 at the line connection 3 after the heat exchanger 7. To limit the pressure used for gas return to the inner tank 1, a pressure reducer 9 with a pressure relief valve 10 connected to it can be installed in the gas return line 6 if necessary.

[0047] Figure 1 This illustrates a single-stage booster with gas recirculation. Figure 2 This invention illustrates a variation with a gas recirculation system incorporating a series pump assembly for two-stage pressurization.

[0048] If very high supply pressures are required (supercritical, e.g., exceeding 20 bar), at least one additional cryogenic pump stage can be connected in series after the first cryogenic pump stage (see [link to relevant documentation]). Figure 2 The final pressure of the first cryogenic pump 21 becomes the suction pressure of the second cryogenic pump 21. Series connection achieves a higher final pressure while reducing energy consumption for compressing the cold gas. Alternatively, a hot compressor for final compression can be connected after the cryogenic pump 21 and heat exchanger 7, outside the tank system.

[0049] Figure 3 This illustration shows a special design for a pump that replaces the delivery pump, taking the form of a linearly driven, double-sided extrusion cryogenic pump 21. It has two opposing extrusion working spaces, each with separate suction and discharge connections for fluid delivery on both sides. The cryogenic pump 21 is thus designed as a linear pump for delivering the storage medium on both sides. Figure 3 It is only in the form of a liquid medium.

[0050] Figure 4 A variation of the linearly driven, dual-sided extrusion cryogenic pump 21 is shown, featuring a separate suction connector (e.g. Figure 3 ), but on one side (in Figure 4 On the left side of the linear pump, there is a switching valve 23 for selectively conveying liquid or gas. Only liquid conveying is performed on the opposite second side of the pump. Furthermore, the cryogenic storage system is designed to... Figures 1 to 3 The variants are the same.

[0051] By installing additional equipment (cryogenic valves, piping) in the inner tank, gas or liquid can selectively flow into the corresponding suction connector via controlled switching of valve positions. For example, in... Figure 4 The valve control device 23 allows for a variable gas-liquid extraction ratio, and therefore the ratio of the mass flow to the consumer 5 to the pressure reduction in the inner tank 1 is also variable. This provides additional freedom in choosing between gas or liquid extraction, as the ratio of the mass flow to the consumer 5 to the pressure reduction in the inner tank 1 is no longer approximately constant and the corresponding amounts can only vary by pump frequency, but are both flexible.

[0052] When valve 23 is open, LH2 floods the pipeline up to the suction connector of cryogenic pump 21 and submerges gas extraction line 24 to the height of LH2 (due to hydrostatic equilibrium). If valve 23 is closed, the remaining LH2 is first discharged from the suction connector before gaseous hydrogen flows from above through gas extraction line 24 into the suction connector.

[0053] Therefore, gas can be extracted from the inner tank 1 through the gas extraction line 24, which serves as an extension of the suction head of the cryogenic pump 21. Liquid or gas can be selectively output from the inner tank 1 via the pump 21 through the on / off valve 23 near the pump for switching from LH2 to GH2.

[0054] If a linear pump with two-sided delivery is used ( Figures 3-6 This results in different extraction variations: the left and right transport streams can, for example, both can transport only LH2, i.e., liquid hydrogen, or one of the sides, for example, the left side can optionally transport GH2 or LH2 while the other side transports only LH2, or both sides can optionally transport GH2 or LH2, i.e., gas or liquid, so that the transported medium is generally variable from 100% GH2 to 100% LH2.

[0055] Figure 4 One variation of these feasibility is shown, which features a linearly driven, dual-sided extrusion cryogenic pump 21 with a connected suction connector that optionally delivers liquid or gas on one side of the pump, here on the left side.

[0056] Figure 5 A variation of the linearly driven, dual-sided extrusion cryogenic pump 21 is shown, featuring separate suction ports, both optionally configured to deliver liquids and / or gases. Switching valves 23 for switching from LH2 to GH2 are respectively arranged on each of the two suction ports of the cryogenic pump 21.

[0057] In the layout described so far, spring-loaded check valves 25 in the filling lines of the inner tank bypass the pump 21 and preferably enter the gas space for filling. It is required that the filling pressure used to open the spring-loaded check valves 25 is higher than the maximum delivery pressure of the cryogenic pump 21. Although the check valves 25 generate additional flow resistance for filling, they avoid flow resistance for the delivery flow from the cryogenic pump 21 to the consumer 5.

[0058] Figure 6 Another configuration of the valve for filling is shown, namely a reversing valve 26 preferably arranged in the inner tank 1. Figure 1 The position of the suspended body is indicated by the cryogenic pump 21. In this embodiment, a spring-loaded check valve 25 is not required.

[0059] A reversing valve 26 is arranged in the pressure line 22 for discharging the transported medium of the cryogenic pump 21. The pressure line 22 for discharging the transported medium transitions at the reversing valve 26 into the inlet line 20 for entering the inner tank 1. This is such that at the reversing valve 26, depending on the state of the reversing valve 26, it either opens to the inlet of the pressure line 22 and closes to the inlet of the inlet line 20, or it closes to the inlet of the pressure line 22 and opens to the inlet of the inlet line 20.

[0060] Therefore, the reversing valve has an inlet to the extraction line 27, which opens both when the inlet to the pressure line 22 is opened and when the inlet to the inlet to the inlet line 20 is opened.

[0061] Reversing valve 26 with integrated suspension body 28 (see Figures 6-8 The symbol ) indicates the switching between extraction and filling. The reversing valve 26 is located at the connection between the pressure line 22, the extraction line 27 and the inlet line 20 to the inner tank 1.

[0062] Suspension 28 during injection ( Figure 7 When the suspension body 28 is in its lower position due to its own weight, it is released into pipe 20 to fill the inner tank. Start-up is achieved by cryogenic pump 21, which lifts / moves the suspension body 28 via a conveying flow, causing it to close the inlet to the filling pipe of the inner tank 1, i.e., into pipe 20. Figure 8 This ensures that the transport flow is pumped only to the consumer 5.

[0063] The advantage of this alternative is that it allows for filling with lower flow resistance and that the filling pressure and the maximum delivery pressure of the cryogenic pump 21 are independent of each other.

[0064] However, the float 28 integrated in the reversing valve 26 creates additional flow resistance to the delivery flow from the cryogenic pump 21 to the consumer 5.

[0065] Both configurations of the switching function, namely the spring-loaded check valve 25 and the reversing valve 26, enable the pressure of the adjacent pipeline and the cryogenic pump 21 to be released into the inner tank 1 when the closed fluid expands due to heating.

[0066] Figure 7 Therefore, the flow in the reversing valve 26 during filling is shown.

[0067] During filling, the weight of the suspension body 28 keeps it in the lower position, allowing the inlet pipe 20 to release for filling the inner tank 1.

[0068] Figure 8 The flow in the reversing valve 26 is shown during extraction by the cryogenic pump 21. When the cryogenic pump 21 is started, the suspension 28 is lifted from the valve seat 29 by the delivery flow, causing it to close to the inlet line 20 of the inner tank 1 and the delivery flow is pumped only to the consumer 5.

[0069] List of reference numerals in the attached diagram:

[0070] 1. Inner tank of the main storage system

[0071] 2 outer containers

[0072] 3 Pipe connection parts

[0073] 4. Supply pipeline

[0074] 5 Consumables

[0075] 6. Gas reflux pipeline

[0076] 7 heat exchangers

[0077] 8 Buffer Containers

[0078] 9 pressure reducers

[0079] 10 Pressure Safety Valve

[0080] 11 Cooling water circuit

[0081] 12. Shut-off valve for supplying H2 to the consumer.

[0082] 13. Shut-off valve for gas reflux to the inner tank

[0083] 14 Interfaces for refueling

[0084] 15GH2 tank valve

[0085] 16LH2 tank valve

[0086] 17 Check valve for gas extraction

[0087] 18-piece safety and gas extraction piping system

[0088] 19 Pressure reducing safety valve

[0089] 20 LH2 enters the inner tank and enters the pipeline

[0090] 21 Cryogenic Pump

[0091] 22 Cryogenic pump pressure line

[0092] 23. Switch valve near the pump for switching from LH2 to GH2.

[0093] 24 Gas extraction pipeline as an extension of the cryogenic pump's suction connector

[0094] 25. Additional check valves

[0095] 26 Reversing valve

[0096] 27 Extraction Pipeline

[0097] 28 suspensions

[0098] 29 Valve seat.

Claims

1. A cryogenic storage system comprising a cryogenic container for storing hydrogen, said cryogenic container having an inner container (1) and an outer container (2), Its features are, At least one cryogenic pump (21) is arranged in the inner tank (1) of the cryogenic container, wherein the cryogenic pump (21) delivers liquid and / or gaseous hydrogen to the consumer (5) in one or more stages through an extraction line (27) at a pressure higher than that in the inner tank (1), wherein the inner tank (1) can be filled through a filling port (14), wherein filling is at least partially carried out through the extraction line (27), wherein filling into the inner tank (1) is achieved by a reversing valve (26), wherein the cryogenic pump (21) A reversing valve (26) is arranged in the pressure line (22) for discharging the transported medium, wherein the pressure line (22) for discharging the transported medium transitions at the reversing valve (26) into the inlet line (20) into the inner tank (1), such that at the reversing valve (26), depending on the state of the reversing valve (26), either the inlet to the pressure line (22) is opened and the inlet to the inlet line (20) is closed, or the inlet to the pressure line (22) is closed and the inlet to the inlet line (20) is opened.

2. The cryogenic storage system according to claim 1, Its features are, The reversing valve has an inlet to the extraction line (27), which is open whether the inlet to the pressure line (22) is open or the inlet to the inlet line (20) is open.

3. The cryogenic storage system according to claim 1, Its features are, The reversing valve (26) has an integrated suspension body (28), wherein the weight of the suspension body (28) holds the suspension body (28) in a lower position, such that the inlet line (20) is released to fill the inner tank (1), wherein, when the cryogenic pump (21) is started, the suspension body (28) is lifted by the delivery flow, such that it closes to the inlet line (20) of the inner tank (1) and pumps the delivery flow only to the consumer (5).

4. The cryogenic storage system according to claim 1, Its features are, The cryogenic pump (21) is designed as a linear pump that delivers to both sides.

5. The cryogenic storage system according to claim 4, Its features are, The delivery flow on the left and / or right sides of a linear pump is designed to selectively deliver gaseous or liquid hydrogen.

6. The cryogenic storage system according to claim 5, Its features are, The delivery flow on the left and / or right side of the linear pump is designed to selectively deliver gaseous or liquid hydrogen via a shut-off valve located near the pump for switching from gaseous to liquid hydrogen.

7. The cryogenic storage system according to claim 1, Its features are, The cryogenic storage system is configured to allow a portion of the heated hydrogen stream, i.e. the portion of the hydrogen extracted after the heat exchanger (7), to be returned to the inner tank (1) via the gas return line (6) to increase the pressure in the inner tank.

8. The cryogenic storage system according to claim 7, Its features are, The cryogenic storage system is configured to allow a portion of the heated hydrogen stream, i.e. the portion of the hydrogen extracted after the heat exchanger (7), to be returned to the inner tank (1) via a shut-off valve in the gas return line (6) to increase the pressure in the inner tank.

9. The cryogenic storage system according to claim 7, Its features are, A pressure reducer (9) is installed in the gas return line (6) used to guide the gas back to the inner tank (1).

10. The cryogenic storage system according to claim 9, Its features are, The pressure regulator has a downstream pressure safety valve (10).

11. The cryogenic storage system according to claim 1, Its features are, A buffer container (8) for heated hydrogen is provided between the cryogenic pump (21) and the consumer (5).

Images