Cryogenic liquid storage tank pressure control system

Abstract

Disclosed is a pressure control system for a cryogenic fluid storage tank. The pressure control system for a cryogenic fluid storage tank according to the present invention includes: a storage tank storing a cryogenic fluid; a discharge line communicating with a lower portion of the storage tank and formed to allow the stored fluid to flow; a first line branched from the discharge line, one end of which is connected to an upper portion of the storage tank to implement gravity-type pressure control; a second line branched from the discharge line, one end of which is connected to a supply target; and a third line branched from a first branch point of the second line, a portion of which passes through the inside of the fluid stored in the storage tank and then forms an outside of the storage tank, the other end of which is connected to the second line at a second branch point, thereby implementing non-gravity-type pressure control.

Description

Technical Field

[0001] This invention relates to a pressure control system for a cryogenic fluid storage tank. More specifically, it relates to a pressure control system for controlling the internal pressure of the storage tank containing the stored fluid in order to smoothly supply fuel to the target (e.g., a fuel cell or hydrogen-powered vehicle) in a pre-set fuel supply (charging) system for cryogenic fluids (e.g., liquefied hydrogen). In particular, it relates to the technical concept of selectively implementing conventional gravity-based and non-gravity-based pressure control methods as needed in a pressure control system with a simple and effective structure. Background Technology

[0002] As the energy problems caused by the use of fossil fuels become increasingly serious, research on alternative fuels is actively underway.

[0003] Among them, the technology of using hydrogen as fuel is both environmentally friendly and efficient, and has attracted much attention as an alternative fuel. It is not only used in hydrogen-powered vehicles that do not use gasoline or diesel but also in small equipment such as drones.

[0004] This type of hydrogen is widely used and stored in a liquefied state. The liquefied hydrogen is stored at extremely low temperatures. Liquefied hydrogen and other cryogenic fluids are stored in tanks and appropriately supplied to pre-defined recipients (such as fuel cells or hydrogen-powered vehicles).

[0005] At this point, in order to supply fluids such as liquid hydrogen smoothly from the storage tank, the internal pressure inside the storage tank must be maintained at an appropriate level. When the internal pressure is low, the fluid supply itself may not be able to be realized normally.

[0006] Therefore, a pressure control method is known for controlling the internal pressure of tanks storing such fluids.

[0007] Figure 1 is a schematic diagram illustrating a conventional pressure control system.

[0008] First, refer to Figure 1a The image shows a gravity-based pressure control method (g-PBU (Pressure Buildup Unit)).

[0009] The gravity-based pressure control method involves using a pipeline connected to the lower end of the storage tank to allow extremely low-temperature liquid fuel (hereinafter referred to as 'fluid') to be discharged naturally by gravity. In order to increase the initial internal pressure, valve V2 is first opened, and the gaseous fuel that has been vaporized after passing through heat exchanger HX2 is injected through pipeline B connected to the upper end of storage tank 10, thereby increasing the internal pressure of storage tank 10.

[0010] Then, when the internal pressure of the storage tank 10 reaches the preset set pressure, valve V1 is opened, and fuel can be supplied to the supply object 20 through pipeline A. In addition, by using the preset automatic pressure regulating device 30, the set pressure can be maintained with valve V2 open.

[0011] When using this gravity-based pressure control method, if the height h of the fluid 11 inside the storage tank 10 is small, the flow rate of the fluid discharged by gravity is very small, so the pressure is practically impossible to rise. In particular, the fluid 11 stored under the influence of gravity is discharged, so it cannot be used when the tilt changes severely or the supply object is overturned during the movement of mobile equipment such as drones or airplanes.

[0012] Unlike this gravity-based pressure control method, there is a non-gravity pressure control method (ng-PBU) that is relatively unaffected by gravity, such as... Figure 1b As shown.

[0013] Figure 1b In this process, a pipeline A can be formed that connects the storage tank 10 to the supply object 20, and a pipeline B that branches off from pipeline A, passes through the interior of the storage tank 10, and then reconnects to pipeline A.

[0014] This non-gravity pressure control method involves supplying fluid 11 (fuel) to the supply object 20 with valve V open. Then, when the internal pressure of the storage tank 10 drops below a certain level, the heated fuel is transferred back to the fluid 11 in the storage tank 10 via pipeline B through heat exchanger HX1, thereby increasing the internal pressure of the storage tank 10. Pressure regulation within the storage tank 10 can be achieved using pressure regulation devices (e.g., 30, 31).

[0015] This non-gravity pressure control method differs from gravity pressure control methods in that it can be activated even when the supplied object is flipped, making it potentially more suitable for mobile equipment such as aircraft or drones.

[0016] However, this traditional non-gravity pressure control method does not discharge fluid 11 to the lower pipeline A of the storage tank 10 when valve V is closed, thus failing to increase the internal pressure of the storage tank 10, which presents difficulties in practical use.

[0017] The problem with this traditional method is that, in the initial stage of fluid supply to the target, before the pressure inside the storage tank reaches the preset pressure, the fluid cannot actually be supplied to the target. Therefore, the waiting time is longer, and it is very inconvenient to use devices using fuels such as liquefied hydrogen. The problems of various methods lead to a decrease in efficiency.

[0018] Therefore, a technological approach is needed that allows gravity-based and non-gravity-based methods to operate selectively within a system as needed, in order to compensate for the shortcomings of each method, simplify its structure, and thus greatly improve manufacturing and usage efficiency.

[0019] Prior technology documents

[0020] -Patent Literature

[0021] Patent Document 1. Korean Patent Registration No. 10-2021038, "Storage Tank" Summary of the Invention

[0022] Technical issues

[0023] The problem to be solved by this invention is to provide a technical concept that enables the selective implementation of traditional gravity-based and non-gravity-based pressure control methods in a pressure control system with a simple and effective structure as needed.

[0024] Technical solutions

[0025] To address the aforementioned technical challenges, the pressure control system according to embodiments of the present invention includes: a storage tank for storing cryogenic fluid; a discharge pipeline connected to the lower part of the storage tank and configured to allow the stored fluid to flow; a first pipeline branching from the discharge pipeline, with one end connected to the upper part of the storage tank to achieve gravity-based pressure control; a second pipeline branching from the discharge pipeline, with one end connected to a supply object; and a third pipeline branching from a first fulcrum of the second pipeline, passing through the interior of the fluid stored in the storage tank, and forming a second end outside the storage tank that connects to the second pipeline at a second fulcrum, thereby achieving non-gravity-based pressure control.

[0026] In addition, the pressure control system of the cryogenic fluid storage tank includes a control unit that controls the flow of the fluid in each pipeline according to the internal pressure of the storage tank. The control unit can control the fluid to pass through the first pipeline before the pressure in the storage tank reaches a preset pressure, and when the pressure in the storage tank reaches the preset pressure, it can control the fluid to be supplied to the target through the second pipeline or the third pipeline.

[0027] Furthermore, the pressure control system of the cryogenic fluid storage tank includes a first valve formed on the first pipeline and controlling the flow of fluid to the first pipeline; and a second valve formed on the second pipeline and controlling the flow of fluid to the second pipeline. The control unit controls the operation of at least one of the first valve or the second valve. Before the pressure inside the storage tank reaches a preset pressure, the first valve is opened to allow the fluid to flow through the first pipeline. When the pressure inside the storage tank reaches the preset pressure, the first valve is closed and the second valve is opened to supply the fluid to the target through the second pipeline. With the second valve open, when the pressure inside the storage tank drops below a preset level, the fluid can be supplied to the target after passing through the third pipeline.

[0028] Additionally, the pressure control system includes a first heat exchanger formed on the first pipeline; a second heat exchanger formed on the second pipeline before the branch of the third pipeline; and a third heat exchanger formed on the third pipeline before connection with the supply object, which can raise the temperature of the fluid flowing through the first heat exchanger, the second heat exchanger, or the third heat exchanger.

[0029] To address the aforementioned technical challenges, another embodiment of the present invention relates to a pressure control system for a cryogenic fluid storage tank, comprising: a storage tank storing cryogenic fluid; a discharge line communicating with the lower part of the storage tank and configured to allow the stored fluid to flow; a first line connected at one end to the discharge line and at the other end to a supply object; a second line branching from the first line at a third fulcrum and communicating with the interior of the storage tank to achieve gravity-based pressure control; and a third line branching from the first line at a fourth fulcrum, passing through the interior of the fluid stored in the storage tank, and forming a fifth fulcrum outside the storage tank, with one end connected to the first line, thereby achieving non-gravity-based pressure control.

[0030] Furthermore, the pressure control system of the cryogenic fluid storage tank includes a control unit that controls the flow of the fluid in each pipeline according to the internal pressure of the storage tank. The control unit can allow the fluid to pass through the second pipeline before the pressure inside the storage tank reaches a preset pressure, and when the pressure inside the storage tank reaches the preset pressure, it can shut off the flow to the second pipeline, controlling the fluid to pass through the first pipeline or the third pipeline before supplying it to the target.

[0031] Additionally, the pressure control system of the cryogenic fluid storage tank includes: a first valve formed on the second pipeline and controlling the fluid flow to the second pipeline; and a second valve formed on the rear end of the first pipeline and controlling the fluid flow to the first pipeline. The control unit can control at least one of the first valve or the second valve according to the internal pressure of the storage tank. Before the pressure inside the storage tank reaches a preset pressure, the first valve is opened to allow the fluid to flow through the second pipeline. When the pressure inside the storage tank reaches the preset pressure, the first pipeline is closed and the second pipeline is opened to supply the fluid to the target through the first pipeline. With the second valve open, when the internal pressure of the storage tank drops below a preset level, the fluid is supplied to the target through the third pipeline.

[0032] Additionally, the pressure control system of the cryogenic fluid storage tank includes: a first heat exchanger formed on the first pipeline before branching off from the second or third pipeline; and a second heat exchanger formed before the third pipeline, branching off from the first pipeline, reconnects to the first pipeline, which can raise the temperature of the fluid flowing through the first or second heat exchanger.

[0033] To address the aforementioned technical challenges, another embodiment of the present invention relates to a pressure control system for a cryogenic fluid storage tank, comprising: a storage tank storing cryogenic fluid; a discharge pipeline communicating with the lower part of the storage tank and forming a discharge line for flowing the stored fluid; a first pipeline connected at one end to the discharge pipeline and the other end to a supply object; a second pipeline branching from the first pipeline at a sixth fulcrum, passing through the interior of the fluid stored in the storage tank, and forming a second pipeline outside the storage tank, one end of which is connected to the seventh fulcrum of the first pipeline and achieving non-gravity pressure control; and a third pipeline branching from the second pipeline at an eighth fulcrum and communicating with the interior of the storage tank to achieve gravity pressure control.

[0034] In addition, the pressure control system of the cryogenic fluid storage tank includes a control unit that controls the flow of the fluid in each pipeline according to the internal pressure of the storage tank. The control unit can control the fluid to pass through the third pipeline before the pressure inside the storage tank reaches a preset pressure, and when the pressure inside the storage tank reaches the preset pressure, it can control the fluid to be supplied to the target through the first pipeline or the second pipeline.

[0035] Additionally, the pressure control system of the cryogenic fluid storage tank includes: a first valve formed on the third pipeline and controlling the flow of fluid to the third pipeline; and a second valve formed on the rear end of the first pipeline and controlling the supply of fluid to the target. The control unit can control the operation of at least one of the first valve or the second valve based on the internal pressure of the storage tank. However, before the pressure inside the storage tank reaches a preset pressure, the first valve is opened to allow the fluid to flow through the third pipeline. When the pressure inside the storage tank reaches the preset pressure, the first valve is closed and the second valve is opened to supply the fluid to the target through the first pipeline. With the second valve open, when the internal pressure of the storage tank drops below a preset level, the fluid is supplied to the target through the second pipeline.

[0036] Additionally, the pressure control system includes: a first heat exchanger formed at a location before the second pipeline branch on the first pipeline; and a second heat exchanger formed at a location before the supply object is connected on the second pipeline, which can raise the temperature of the fluid flowing through the first heat exchanger or the second heat exchanger.

[0037] The effects of the invention

[0038] In a pressure control system according to one embodiment of the present invention, conventional gravity-type and non-gravity-type pressure control methods can be selectively implemented with a simple and effective structure, which can truly increase the capacity of the pressure control system (gravity-type + non-gravity-type) and can relatively quickly increase the initial pressure inside the storage tank containing fluids such as liquefied hydrogen, thereby significantly shortening the waiting time for fuel (such as liquefied hydrogen) to be charged. Attached Figure Description

[0039] To provide a fuller understanding of the accompanying drawings referenced in the detailed description of the invention, a brief description of each drawing is provided.

[0040] Figure 1 is a schematic diagram illustrating a conventional pressure control system.

[0041] Figure 2 The diagram shows a schematic structure of the pressure control system for a cryogenic fluid storage tank according to an embodiment of the present invention.

[0042] Figure 3 The diagram shows a schematic structure of a pressure control system for a cryogenic fluid storage tank according to another embodiment of the present invention.

[0043] Figure 4 The diagram shows a schematic structure of a pressure control system for a cryogenic fluid storage tank according to another embodiment of the present invention. Detailed Implementation

[0044] This invention can be modified in various ways and has multiple embodiments, which are specifically illustrated in detail with reference to the accompanying drawings. However, this is not intended to limit the specific implementation of the invention, but should be understood to include all modifications, similarities, and even substitutions within the spirit and scope of the invention. In the description of the invention, detailed descriptions of relevant disclosed technologies are omitted if they might lead to ambiguity regarding the gist of the invention.

[0045] Terms such as "first" and "second" can be used to describe various constituent elements, but the constituent elements cannot be limited by the terms. The purpose of using these terms is merely to distinguish one constituent element from other constituent elements.

[0046] The terminology used in this application is for illustrative purposes only and is not intended to limit the invention. Singular expressions include plural expressions in the context unless there is a clear difference in meaning.

[0047] In this specification, terms such as "including" or "owning" are used to specify the presence of features, figures, stages, actions, constituent elements, components or combinations thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features or figures, stages, actions, constituent elements or components or combinations thereof.

[0048] The invention will now be described in detail with reference to the accompanying drawings and embodiments thereof. The same reference numerals in each drawing represent the same components.

[0049] Figure 2 The diagram shows a schematic structure of a cryogenic fluid storage tank pressure control system according to an embodiment of the present invention.

[0050] Reference Figure 2The present invention relates to a cryogenic fluid storage tank pressure control system 1 (hereinafter referred to as 'pressure control system'), comprising: a storage tank 10 storing cryogenic fluid 11; a discharge pipeline 100 connected to the lower part of the storage tank 10 and forming a discharge line for flowing the stored fluid; a first pipeline 110a branching from the discharge pipeline 100, one end of which is connected to the upper part of the storage tank 10 to achieve gravity-based pressure control; a second pipeline 120a branching from the discharge pipeline 100, one end of which is connected to a supply object 20; and a third pipeline 130a branching from a first fulcrum of the second pipeline 120a, a portion of which passes through the fluid 11 stored in the storage tank 10 and forms a third pipeline outside the storage tank 10, the other end of which connects to the second pipeline 120a at a second fulcrum to achieve non-gravity-based pressure control. The position of the first fulcrum may refer to a position relatively closer to the discharge pipeline 100 compared to the second fulcrum. Additionally, as will be discussed later, when a heat exchanger (e.g., 210) is installed in the second pipeline 120a, the first fulcrum and the second fulcrum may be located after the heat exchanger (e.g., 210) on the discharge pipeline 100.

[0051] Additionally, the pressure control system 1 may include: a first valve 300 formed on the first pipeline 110a to control the flow of fluid 11 to the first pipeline 110a; a second valve 310 formed on the second pipeline 120a to control the flow of fluid to the second pipeline 120a; a control unit (e.g., 420) to control the operation of the first valve 300 according to the internal pressure of the storage tank 10; and a control unit (e.g., 400, 410) to control the second valve 310.

[0052] The control unit (e.g., 400, 410, 420) may refer to a device or system that opens or closes the valves and / or pipelines according to the pressure inside the storage tank 10, so that the fluid 11 passes through specific pipelines.

[0053] For example, the control unit (e.g., 400, 410) can be configured with a mechanical structure that automatically operates when the internal pressure of the tank 10 reaches a specific pressure, or it can be configured with an electronic structure that senses the internal pressure of the tank 10 according to the implemented case and operates based on the pressure value sensed by the sensor. In any case, the control unit (e.g., 400, 410) is configured to control the opening / closing of pipelines (such as valves and / or pipelines) through which the fluid 11 will flow based on the internal pressure of the tank 10.

[0054] The pressure control method of the pressure control system 1 according to the technical concept of the present invention is described below.

[0055] The pressure control system 1 uses the same method as the conventional gravity-based pressure control method during the initial operation phase, which can effectively increase the initial pressure inside the storage tank 10. For example, the pressure control system 1 can open the first valve 300 and circulate the fluid through the first pipeline 110a until the pressure inside the storage tank 10 reaches a preset set pressure (e.g., 11 bar, which can be set according to the type of fluid 11 or the capacity of the storage tank 10, etc.). The control of the first valve 300 can be executed by a control unit (e.g., 420). At this time, the second valve 310 can be in the closed state.

[0056] Furthermore, when the pressure inside the storage tank 10 reaches the set pressure, the control unit (e.g., 400, 410) can open the second valve 310 after closing the first valve 300, and supply the fluid 11 to the supply object 20 through the second pipeline 120a.

[0057] In this specification, the supply object 20 may be a pre-defined object that needs to be supplied or filled with the fluid stored in the storage tank 10.

[0058] In one embodiment, when the cryogenic fluid 11 stored in the storage tank 10 is liquefied hydrogen, the supply target 20 can refer to a fuel cell that uses hydrogen as fuel or a hydrogen-powered vehicle that uses hydrogen directly as fuel. Of course, if the fluid 11 is not liquid hydrogen but another type, the object requiring charging of the fluid 11 can also be the supply target 20. In the following description of this specification, the example is that the fluid 11 is liquefied hydrogen and the supply target 20 is a fuel cell or hydrogen-powered vehicle that requires hydrogen charging (supply), but the present invention is not necessarily limited to this.

[0059] In addition, the fact that the fluid 11 is supplied to the supply object 20 and / or the storage tank 10 may mean that the fluid 11 is supplied directly to the supply object 20 in the state of fluid 11, or it may refer to the situation where it is supplied in a state of vaporization or temperature rise through other pre-set components (e.g., heat exchangers, etc.), as described later.

[0060] Furthermore, during the process of the second valve 310 opening and supplying the fluid 11 to the supply target 20 through the second pipeline 120a, the amount of fluid 11 stored in the storage tank 10 decreases, and the pressure inside the storage tank 10 may drop below the pressure required by the supply target 20. In this case, the control unit (e.g., 400, 410) can supply the fluid 11 not only directly to the supply target 20 through the second pipeline 120a, but also after passing through the third pipeline 130a. As shown in the figures, the third pipeline 130a can be configured to pass through the interior of the storage tank 10 and intersect (connect) with the second pipeline 120a again outside the storage tank 10. Furthermore, the third pipeline 130a is configured to partially pass through the interior of the fluid 11 stored in the storage tank 10, thereby allowing the fluid 11 inside the storage tank 10 to heat up, causing the pressure inside the storage tank 10 to rise again. Furthermore, the third pipeline 130a is reconnected to the second pipeline 120a, allowing the fluid 11 to be supplied to the target 20. At this time, the first valve 300 can remain closed.

[0061] Subsequently, when the internal pressure of the storage tank 10 reaches the set pressure, the control unit (e.g., 400, 410) can supply the fluid 11 directly to the supply object 20 without passing through the third pipeline 130a.

[0062] On the other hand, when storing a pre-defined gas such as liquefied hydrogen after liquefaction, the temperature of the liquefied fluid 11 may need to be maintained at an extremely low temperature. In order to supply this extremely low-temperature fluid 11 to the supply object 20, or, similar to the first pipeline 110, to increase the internal pressure of the storage tank 10 by injecting it into the storage tank 10, it is necessary to raise the temperature of the fluid 11. For this purpose, the pressure control system 1 may include at least one heat exchanger (e.g., 200, 210, 220).

[0063] exist Figure 2 In the illustrated embodiment, the at least one heat exchanger (e.g., 200, 210, 220) may be disposed on the first pipeline 110a, the second pipeline 120a, and the third pipeline 130a, respectively.

[0064] In the at least one heat exchanger, the first heat exchanger 200 is located after the first valve 300 of the first pipeline 110a, and when the first valve 300 is open, the fluid 11 discharged through the discharge pipeline 100 can undergo heat exchange as it passes through the first pipeline 110a. Thus, the fluid 11 passing through the first heat exchanger 200 on the first pipeline 110a is vaporized and re-injected into the storage tank 10, thereby increasing the internal pressure of the storage tank 10.

[0065] Furthermore, the second heat exchanger 210 is installed on the second pipeline 120a, which enables heat exchange of the fluid 11 supplied to the supply object 20.

[0066] The third pipeline 130a can branch off from the second heat exchanger 210 on the second pipeline 120a, as described above, and intersect with the second pipeline 120a again after passing inside the storage tank 10. Furthermore, the third heat exchanger 220 can be formed outside the storage tank 10 after the third pipeline 130a passes inside the storage tank 10, before intersecting with the second pipeline 120a again, thereby enabling heat exchange and allowing the fluid 11 passing through the third pipeline 130a to be smoothly supplied to the target 20.

[0067] According to the technical concept of the present invention, in a pressure control system 1, conventional gravity-based and non-gravity-based pressure control methods can be selectively implemented as needed with a simple and effective structure. Therefore, the present invention can truly achieve the capacity-increasing effect of the pressure control system 1 (gravity-based + non-gravity-based), and can relatively quickly increase the initial pressure inside the storage tank 10, thereby significantly shortening the fuel (e.g., liquefied hydrogen) charging waiting time.

[0068] Figure 3 The diagram shows a schematic structure of a pressure control system for a cryogenic fluid storage tank according to another embodiment of the present invention.

[0069] Reference Figure 3Another embodiment of the present invention relates to a pressure control system 1, which may include: a storage tank 10 storing a cryogenic fluid 11; a discharge line 100 communicating with the lower part of the storage tank 10 and forming a flow path for the stored fluid; and a first line 110b connected at one end to the discharge line 100 and at the other end to a supply object 20. The pressure control system 1 may also include a second line 120b branching from the first line 110b at a third fulcrum and communicating with the upper space of the storage tank 10 to achieve gravity-based pressure control; and a third line 130b branching from the first line 110b at a fourth fulcrum, a portion of which, after passing through the fluid 11 stored in the storage tank 10, forms a fifth fulcrum outside the storage tank 10, connecting at one end to the first line 110b, to achieve non-gravity-based pressure control.

[0070] The third support point likely refers to a position relatively closer to the discharge pipeline 100 compared to the fourth support point. That is, in Figure 3 In the illustrated embodiment, compared to the third pipeline 130b, the second pipeline 120b branches off from the first pipeline 110b first, and the third pipeline 130b may branch off at a position after the branch of the second pipeline 120b. Furthermore, the fifth fulcrum where the third pipeline 130b reconnects to the first pipeline 110b may refer to a position after the third and fourth fulcrums. Additionally, if a heat exchanger (e.g., 200) is installed on the first pipeline 110b, the third and fourth fulcrums may be located after the discharge pipeline 100 passes through the heat exchanger (e.g., 200).

[0071] like Figure 3 As shown, with Figure 2 Compared to the illustrated embodiment, another embodiment of the present invention relates to a pressure control system 1 characterized in that the pipeline for increasing the internal pressure of the storage tank 10 by gravity-based pressure control is not a separate branch from the discharge pipeline 100, but rather a branch from the first pipeline 110b.

[0072] and Figure 2 Compared to the embodiments described herein, it has a relatively simple structure. For example, according to... Figure 3 Another embodiment of the invention shown illustrates a pressure control system 1 that does not require a separate heat exchanger for gravity-based pressure control methods (e.g., Figure 2 The first heat exchanger 200 can reduce the number of heat exchangers required.

[0073] As shown in the figure, the second pipeline 120b for implementing gravity-based pressure control can branch off at a location after the first heat exchanger 200 of the first pipeline 110b.

[0074] Furthermore, a first valve 300 for controlling the inflow of fluid 11 into the second pipeline 120b can be formed on the second pipeline 120b. In the initial stage, with the first valve 300 open and the second valve 310 formed at the rear end of the first pipeline 110b closed, fluid 11 discharged from the storage tank 10 through the discharge pipeline 100 passes through the first heat exchanger 200 and then is injected into the storage tank 10 after being vaporized through the second pipeline 120b, thereby increasing the internal pressure of the storage tank 10.

[0075] Subsequently, when the internal pressure of the storage tank 10 reaches the preset pressure, the first valve 300 is closed and the second valve 310 is opened, and the fluid 11 can be vaporized through the first pipeline 110b and supplied to the supply object 20.

[0076] During the process of supplying fluid 11 to the supply object 20, if the pressure inside the storage tank 10 drops, the control unit (e.g., 400, 410) can control the fluid 11 to pass through the third pipeline 130b.

[0077] This composition is consistent with the aforementioned Figure 2 As described above, non-gravity pressure control is achieved through the third pipeline 130b. The extremely low temperature fluid 11 stored in the storage tank 10 is cooled down and then rises again through the second heat exchanger 210 before being supplied to the supply object 20.

[0078] Figure 4 The diagram shows a schematic structure of a pressure control system for a cryogenic fluid storage tank according to another embodiment of the present invention.

[0079] Reference Figure 4 Another embodiment of the pressure control system 1 of the present invention may include: a storage tank 10 storing a cryogenic fluid 11; a discharge line 100 connected to the lower part of the storage tank 10 to allow the stored fluid to flow through; and a first line 110c connected at one end to the discharge line 100 and at the other end to a supply object 20. Furthermore, the pressure control system 1 is configured to branch from the first line 110c at a sixth fulcrum to achieve… Figure 2 and / or Figure 3 The non-gravity pressure control shown may include a third pipeline 130c, a second pipeline 120c with one end connected to the seventh fulcrum of the first pipeline 110c outside the tank 10, and a branch from the eighth fulcrum of the second pipeline 120c that communicates with the upper space of the tank 10 to achieve gravity pressure control.

[0080] The sixth support point can refer to a position that is relatively closer to the discharge pipeline 100 compared to the seventh support point. That is, in Figure 4 In one embodiment, the second pipeline 120c first branches off from the first pipeline 110c (sixth fulcrum), and then, through a non-gravity pressure control process, can reconnect to the first pipeline 110c at a position after the sixth fulcrum (seventh fulcrum). Alternatively, when a heat exchanger (e.g., 200) is installed on the first pipeline 110c, the sixth and seventh fulcrums can be located after the discharge pipeline 100 passes through the heat exchanger (e.g., 200).

[0081] Furthermore, another embodiment of the present invention relates to a pressure control system 1 and Figure 3 Similar to the pressure control system 1 described in another embodiment of the invention, the separate line for gravity-based pressure control does not branch off from the discharge line 100, but... Figure 3 The difference between the embodiments in the text and the ones in the text is that the pipeline used for gravity pressure control (i.e. Figure 4 The third pipeline (130c) is the pipeline used for non-gravity pressure control (i.e. Figure 4 The 8th branch point of the second pipeline 120c is mentioned. The 8th branch point can be any position distinguished for ease of explanation, but ideally, the 6th branch point refers to the position between the branch point of the second pipeline 120c from the first pipeline 110c and the position before the second pipeline 120c enters the interior of the storage tank 10. That is, according to the technical concept of the present invention, fluid 11 passing through the heat exchanger (e.g., 200) on the first pipeline 110c can flow from the 6th branch point to the second pipeline 120c, and then directly through the second pipeline 120c as needed, achieving non-gravity pressure control, or gravity pressure control can be achieved after passing through the third pipeline 130c.

[0082] The characteristic of this invention is that, according to the technical concept of the invention, a pipeline for non-gravity pressure control is formed inside the storage tank 10, while a pipeline for rapidly increasing the initial pressure through gravity pressure control is formed in the initial stage of operation, thus selectively using gravity and non-gravity pressure control methods with a relatively simple structure.

[0083] Figure 4 In another embodiment of the invention shown, the pressure control system 1 involves a heat exchanger that can be connected to... Figure 3 Formed at the same or similar locations as described above. For example, in Figure 4In the illustrated embodiment, the first heat exchanger 200 may be formed at the front end of the first pipeline 110c, and the second heat exchanger 210 may be formed at the rear end of the pipeline that implements non-gravity pressure control, i.e., the second pipeline 120c.

[0084] The above description of the present invention is merely illustrative. Those skilled in the art will understand that it can be easily modified into other specific forms without altering the technical concept or essential characteristics of the invention. Therefore, the embodiments described above are merely illustrative in all respects and must be understood as non-limiting. For example, each component described individually can be implemented separately; similarly, components described as distributed can be implemented in combination.

[0085] The scope of this invention is defined by the scope of the patent application rather than by the specific description above, and any changes or modifications derived from the equivalent concepts of the patent application should be interpreted as being included within the scope of this invention.

[0086] Industrial availability

[0087] This invention can be used in the pressure control system of cryogenic fluid storage tanks.

Claims

1. A pressure control system for a cryogenic fluid storage tank, comprising: Storage tanks for storing cryogenic fluids; A discharge pipeline is formed by communicating with the lower part of the storage tank to allow the stored fluid to flow. A branch line originates from the discharge pipeline and connects at one end to the upper part of the storage tank, forming a first pipeline for gravity-controlled pressure. A second pipeline branches off from the discharge pipeline and connects to the supply object; as well as One end branches off from the first fulcrum of the second pipeline, and after passing through the interior of the fluid stored in the storage tank, a third pipeline is formed outside the storage tank, with the other end connected to the second pipeline at the second fulcrum, thereby realizing non-gravity pressure control. The pressure control system of the cryogenic fluid storage tank also includes a control unit that controls the flow of the fluid in each pipeline based on the internal pressure of the storage tank. The control unit, Before the pressure in the storage tank reaches a preset pressure, the fluid is directed to pass through the first pipeline. When the pressure in the storage tank reaches the preset pressure, the fluid is directed to pass through the second pipeline or the third pipeline and then supplied to the target.

2. The pressure control system for the cryogenic fluid storage tank according to claim 1, comprising: A first valve formed on the first pipeline and controlling the flow of fluid to the first pipeline; as well as A second valve formed on the second pipeline and controlling the flow of fluid to the second pipeline. The control unit, Controlling the operation of at least one of the first valve or the second valve. Before the pressure inside the storage tank reaches a preset pressure, the first valve is opened to allow the fluid to flow through the first pipeline. When the pressure inside the storage tank reaches the preset pressure, the first valve is closed and the second valve is opened to supply the fluid to the target object through the second pipeline. With the second valve open, when the internal pressure of the storage tank drops below a set level, the fluid can be supplied to the target after passing through the third pipeline.

3. The pressure control system for the cryogenic fluid storage tank according to claim 1, comprising: The first heat exchanger is formed on the first pipeline; A second heat exchanger is formed at a location preceding the branch of the second pipeline and the third pipeline; and The third heat exchanger is formed at a location prior to the third pipeline and before it is connected to the object being supplied. A pressure control system that allows the temperature of the fluid flowing through the first heat exchanger, the second heat exchanger, or the third heat exchanger to rise.

4. A pressure control system for a cryogenic fluid storage tank, comprising: Storage tanks for storing extremely low temperature fluids; A discharge pipeline is formed by communicating with the lower part of the storage tank to allow the stored fluid to flow. A first pipeline, with one end connected to the discharge pipeline and the other end connected to the supply object; The second pipeline, which branches off from the first pipeline at the third fulcrum, connects to the inside of the storage tank to achieve gravity-based pressure control. as well as A third pipeline, branching off from the first pipeline at the fourth fulcrum, passes through the fluid stored in the tank and forms a fifth fulcrum outside the tank, connecting one end to the first pipeline, thereby achieving non-gravity pressure control. The pressure control system of the cryogenic fluid storage tank also includes: The control unit controls the flow of fluid in each pipeline based on the internal pressure of the storage tank. The control unit, Before the pressure in the storage tank reaches the preset set pressure, the fluid is allowed to pass through the second pipeline. When the pressure in the storage tank reaches the set pressure, the flow to the second pipeline is shut off, and the fluid is controlled to flow through the first pipeline or the third pipeline before being supplied to the target.

5. The pressure control system for the cryogenic fluid storage tank according to claim 4, comprising: A first valve formed in the second pipeline to control the flow of fluid to the second pipeline; as well as A second valve, formed at the rear end of the first pipeline, controls the flow of fluid into the first pipeline; The control unit, The operation of at least one of the first valve or the second valve is controlled based on the internal pressure of the storage tank. The pressure control system of the cryogenic fluid storage tank opens the first valve before the pressure inside the tank reaches a preset pressure, allowing the fluid to flow through the second pipeline. When the pressure inside the tank reaches the preset pressure, the first valve is closed and the second valve is opened, supplying the fluid to the target object through the first pipeline. With the second valve open, when the internal pressure of the storage tank drops below a preset level, the fluid can be supplied to the target through the third pipeline.

6. The pressure control system for the cryogenic fluid storage tank according to claim 4, comprising: A first heat exchanger is formed on the first pipeline and at a location before the branch of the second or third pipeline; as well as The second heat exchanger is formed at the position before the third pipeline, which branches off from the first pipeline, reconnects to the first pipeline. The temperature of the fluid flowing through the first heat exchanger or the second heat exchanger can rise.

7. A pressure control system for a cryogenic fluid storage tank, comprising: Storage tanks for storing extremely low temperature fluids; A discharge pipeline is formed by communicating with the lower part of the storage tank to allow the stored fluid to flow. A first pipeline, with one end connected to the discharge pipeline and the other end connected to the supply object; A second pipeline, branching off from the first pipeline at point 6, passes through the fluid stored in the tank and then forms an external connection at point 7 with the first pipeline, thus achieving non-gravity pressure control; and A third pipeline, which branches off from the second pipeline at the eighth fulcrum and connects to the inside of the storage tank, is used to achieve gravity-based pressure control. The pressure control system of the cryogenic fluid storage tank also includes The control unit controls the flow of the fluid in each pipeline based on the internal pressure of the storage tank. The control unit, Before the pressure in the storage tank reaches a preset pressure, the fluid is allowed to flow through the third pipeline. When the pressure in the storage tank reaches the preset pressure, the fluid is controlled to flow through the first pipeline or the second pipeline and then supplied to the target.

8. The pressure control system for the cryogenic fluid storage tank according to claim 7, comprising: A first valve formed in the third pipeline, controlling the flow of fluid to the third pipeline; and A second valve, formed at the rear end of the first pipeline, controls the fluid supply to the object being supplied. The control unit, The operation of at least one of the first valve or the second valve is controlled according to the internal pressure of the storage tank. Before the pressure inside the storage tank reaches a preset pressure, the first valve is opened to allow the fluid to flow through the third pipeline. When the pressure inside the storage tank reaches the preset pressure, the first valve is closed and the second valve is opened to supply the fluid to the target object through the first pipeline. When the second valve is open and the internal pressure of the storage tank drops below a preset level, the fluid can be supplied to the target object via the second pipeline.

9. The pressure control system for the cryogenic fluid storage tank according to claim 7, comprising: A first heat exchanger is formed on the first pipeline and at a location before the branch of the second pipeline; as well as A second heat exchanger is formed on the second pipeline and at a location prior to its connection with the object being supplied. The temperature of the fluid passing through the first heat exchanger or the second heat exchanger can rise.

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