Water injection and drainage system of LNG fuel tank

Abstract

The invention relates to the technical field of LNG engineering, in particular to a water injection and drainage system of an LNG fuel tank. The water injection and drainage system of the LNG fuel tank comprises a first pipeline, a second pipeline, a third pipeline, a submersible pump, a water injection pipeline and a drainage pipeline, the first pipeline is fixed to an auxiliary structure on one side of the fuel tank in the vertical direction, the upper end of the first pipeline communicates with the fuel tank through the second pipeline, a first connector in the lower end communicates with the water injection pipeline, and a second connector communicates with the drainage pipeline; the submersible pump is arranged at the bottom in the fuel tank and communicates with the second pipeline through a third pipeline. Therefore, water injection and water drainage of the tall and large fuel tank without a bottom outlet are achieved, water injection and water drainage are achieved through a common pipeline, and the water injection and drainage system is more convenient to install. Meanwhile, the first pipeline is fixed through an auxiliary structure beside the fuel tank, so that the fuel-free tank can be prevented from being damaged and can be reused; and meanwhile, the problem of physical suction stroke limit of a ground self-priming pump is avoided, so that water in the fuel tank can be effectively discharged.

Description

Technical Field

[0001] This application relates to the field of LNG engineering technology, and in particular to an injection and drainage system for an LNG fuel tank. Background Technology

[0002] LNG (liquefied natural gas) fuel tanks typically require pipelines for water injection and drainage to conduct hydrostatic tests. Conventional fuel tanks with a bottom outlet usually use the bottom outlet to connect the water injection and drainage pipelines. However, for tall fuel tanks without a bottom outlet, the pipelines need to be led to the top of the tank and welded to the tank wall. But for tanks made of special materials, welding can damage the structural integrity and corrosion resistance of the tank. In addition, drainage is usually carried out using a ground self-priming pump, but due to the limitation of physical suction head, it is often impossible to empty the water completely. Summary of the Invention

[0003] The purpose of this invention is to provide an injection and drainage system for LNG fuel tanks, so as to facilitate the arrangement of water injection and drainage pipelines for tall fuel tanks without bottom outlets.

[0004] The present invention provides an injection and drainage system for an LNG fuel tank, comprising a first pipe, a second pipe, a third pipe, a submersible pump, an injection pipe, and a drainage pipe; The first pipe is used to be fixed vertically to an auxiliary structure on one side of the fuel tank. The upper end of the first pipe extends to the top of the fuel tank, and the upper end of the first pipe is connected to the top of the fuel tank through the second pipe. The submersible pump is installed inside the fuel tank and arranged at the bottom of the fuel tank, and the outlet of the submersible pump is connected to the second pipe through the third pipe; The lower end of the first pipe extends to the bottom of the fuel tank. The lower end of the first pipe has a first interface and a second interface. The first interface is used to connect to the water injection pipe, and the second interface is used to connect to the drainage pipe.

[0005] Furthermore, the LNG fuel tank's injection and drainage system also includes a water injection pump; The water injection pipeline is connected to an external water source via the water injection pump.

[0006] Furthermore, a check valve and a first shut-off valve are sequentially installed on the water injection pipe along the flow direction; Alternatively, a shut-off check valve may be installed on the water injection pipeline.

[0007] Furthermore, a second shut-off valve is installed on the drainage pipe.

[0008] Furthermore, a first pressure gauge is installed on the water injection pipe.

[0009] Furthermore, both the first pipe and the water injection pipe are rigid pipes; The water inlet of the water pump is connected to a fire-fighting suction hose, and the water is connected to an external water source through the fire-fighting suction hose.

[0010] Furthermore, the second pipe is a fire hose.

[0011] Furthermore, the top of the fuel tank is provided with a first inlet, and a connecting pipe is installed at the first inlet; One end of the connecting pipe is connected to the fuel tank, and the other end of the connecting pipe forms a third interface, which is connected to the second pipe.

[0012] Furthermore, the end of the connecting pipe that forms the third interface also forms a fourth interface, which is connected to the third pipe.

[0013] Furthermore, a second pressure gauge and a third shut-off valve are installed on the connecting pipe.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The LNG fuel tank injection and drainage system provided by this invention includes a first pipe, a second pipe, a third pipe, a submersible pump, a water injection pipe, and a drainage pipe. The first pipe is vertically fixed to an auxiliary structure on one side of the fuel tank, with its upper end extending to the top of the fuel tank and its lower end extending to the bottom of the fuel tank. The second pipe is located at the top of the fuel tank, with one end connected to the fuel tank and the other end connected to the upper end of the first pipe. The submersible pump is located inside the fuel tank and at its bottom. One end of the third pipe extends into the fuel tank and is connected to the outlet of the submersible pump, while the other end extends from the top of the fuel tank and is connected to the second pipe, allowing the outlet of the submersible pump to connect to the first pipe via the second pipe. The lower end of the first pipe has a first interface and a second interface; the first interface is used to connect to the water injection pipe, and the second interface is used to connect to the drainage pipe.

[0015] Therefore, during the hydrostatic test of the fuel tank, water can be injected into the fuel tank through the injection pipe, the first pipe, and the second pipe. Then, a submersible pump can drain the fuel tank through the third pipe, the second pipe, the third pipe, and the drainage pipe. This allows for the injection and drainage of the tall fuel tank without a bottom outlet, and the injection and drainage share the same pipelines (the first and second pipes), making the installation of the entire injection and drainage system more convenient. At the same time, the first pipe is fixed by the auxiliary structure next to the fuel tank, which can avoid damage to the fuel tank and can be reused in multiple hydrostatic tests, thereby reducing the operating cost. Furthermore, by using a submersible pump built into the fuel tank for drainage, compared to using an external ground self-priming pump, the problem of the physical suction head limit of the self-priming pump can be effectively avoided, and the water in the fuel tank can be effectively drained. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the injection and drainage system for an LNG fuel tank provided in an embodiment of the present invention; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 for Figure 1 Enlarged view of section B in the middle.

[0018] Figure label: 1-Fuel tank, 2-Auxiliary structure, 3-First pipeline, 4-Second pipeline, 5-Third pipeline, 6-Submersible pump, 7-Water injection pipeline, 71-Stop check valve, 72-First pressure gauge, 73-Water injection pump, 74-Fire suction hose, 8-Drainage pipeline, 81-Second shut-off valve, 9-Connecting pipe, 91-Second pressure gauge, 92-Third shut-off valve. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] The components of the embodiments of the invention described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0021] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] The following reference Figures 1 to 3 This application describes an LNG fuel tank injection and drainage system according to some embodiments.

[0025] This application provides an injection and drainage system for an LNG fuel tank, such as... Figures 1 to 3As shown, the LNG fuel tank's injection and drainage system includes a first pipe 3, a second pipe 4, a third pipe 5, a submersible pump 6, an injection pipe 7, and a drainage pipe 8. The first pipe 3 is used to fix the auxiliary structures 2 (such as modular scaffolding, boarding towers, etc.) vertically to one side of the fuel tank 1, and the upper end of the first pipe 3 extends to the top of the fuel tank 1, while the lower end of the first pipe 3 extends to the bottom of the fuel tank 1. The second pipe 4 is arranged on the top of the fuel tank 1, and the top of the fuel tank 1 is provided with a first connecting port. One end of the second pipe 4 is connected to the first connecting port to communicate with the fuel tank 1, and the other end of the second pipe 4 is connected to the upper end of the first pipe 3, thereby connecting the first pipe 3 to the fuel tank 1 through the second pipe 4. The submersible pump 6 is installed inside the fuel tank 1 and arranged at the bottom of the fuel tank 1. The top of the fuel tank 1 is provided with a second connecting port. The third pipe 5 is installed at the second interface pipe. One end of the third pipe 5 extends into the fuel tank 1 and is connected to the outlet of the submersible pump 6. The other end of the third pipe 5 extends out of the top of the fuel tank 1 and is connected to the second pipe 4, so that the outlet of the submersible pump 6 can be connected to the first pipe 3 through the second pipe 4.

[0026] The lower end of the first pipe 3 has a first interface and a second interface. For example, a tee connector is installed at the lower end of the first pipe 3. One port of the tee connector is connected to the lower end of the first pipe 3, and the other two ports of the tee connector form the first interface and the second interface. The first interface is used to connect to the water injection pipe 7, and the second interface is used to connect to the drainage pipe 8.

[0027] Therefore, during the hydrostatic test of fuel tank 1, water can be injected into fuel tank 1 through water injection pipe 7, first pipe 3, and second pipe 4. Then, submersible pump 6 can drain water from fuel tank 1 through third pipe 5, second pipe 4, and drainage pipe 8, thus realizing the injection and drainage of the tall fuel tank 1 without a bottom outlet. The injection and drainage share the same pipeline (first pipe 3 and second pipe 4), making the installation of the entire injection and drainage system more convenient. At the same time, the first pipe 3 is fixed by the auxiliary structure 2 next to fuel tank 1, which can avoid damage to fuel tank 1 and can be reused in multiple hydrostatic tests to reduce the cost of use. In addition, by using submersible pump 6 built into fuel tank 1 for drainage, compared with the use of external ground self-priming pump, the problem of the physical suction head limit of self-priming pump can be effectively avoided, and the water in fuel tank 1 can be effectively drained.

[0028] In this embodiment, the LNG fuel tank's water injection and drainage system also includes a water injection pump 73, which is fixed to a base platform at the bottom of the fuel tank 1. A water injection pipe 7 is horizontally arranged and supported on the base platform by pads. One end of the water injection pipe 7 is connected to a first interface, and the other end of the water injection pipe 7 is connected to the outlet of the water injection pump 73. The inlet of the water injection pump 73 is used to connect to an external water source so that water can be injected into the fuel tank 1 using the water injection pump 73.

[0029] In this embodiment, preferably, as follows: Figure 2 As shown, a check valve and a first shut-off valve are installed on the water injection pipe 7. The check valve and the first shut-off valve are arranged sequentially along the flow direction of the water in the water injection pipe 7, that is, the check valve is located between the outlet of the water injection pump 73 and the first shut-off valve. Alternatively, a shut-off check valve 71 is installed on the water injection pipe 7. Thus, water diversion can be prevented when filling the fuel tank 1 with water, and the water injection pipe 7 can be closed when draining water.

[0030] In this embodiment, preferably, as follows: Figure 2 As shown, the drain pipe 8 is arranged vertically, and the upper end of the drain pipe 8 is connected to the second interface. A second shut-off valve 81 is installed on the drain pipe 8. When water is injected, the drain pipe 8 can be closed through the second shut-off valve 81 so that water can be injected into the fuel tank 1 smoothly. When draining, the water injection pipe 7 is closed and the second shut-off valve 81 is opened so that water can be drained from the fuel tank 1 smoothly.

[0031] In this embodiment, preferably, as follows: Figure 2 As shown, a first pressure gauge 72 is installed on the water injection pipe 7. Specifically, the first pressure gauge 72 is installed between the shut-off check valve 71 (or check valve) and the outlet of the water injection pump 73 to monitor the water injection pressure.

[0032] In this embodiment, preferably, both the first pipe 3 and the water injection pipe 7 are rigid pipes, such as rigid polyvinyl chloride pipes, to facilitate installation and fixation, reuse multiple times, and stable water delivery.

[0033] In this embodiment, preferably, as follows: Figure 2 As shown, the inlet of the water injection pump 73 is connected to a fire-fighting suction hose 74, and is connected to an external water source through the fire-fighting suction hose 74, thereby facilitating the connection between the water injection pump 73 and the external water source.

[0034] In this embodiment, preferably, the second pipe 4 is a fire hose, which facilitates connecting the second pipe 4 to the upper end of the first pipe 3 and the first connecting port on the top of the fuel tank 1.

[0035] In one embodiment of this application, preferably, as shown below, Figure 1 and Figure 3As shown above, the fuel tank 1 has a first inlet on its top and a connecting pipe 9 on its top. The connecting pipe 9 is installed at the first inlet, with one end extending into the fuel tank 1 to connect with it, and the other end extending out of the fuel tank 1 to form a third interface and a fourth interface. The third interface is used to connect with the second pipe 4, so that the second pipe 4 is connected to the fuel tank 1, and the fourth interface is used to connect with the third pipe 5, so that the third pipe 5 is connected to the second pipe 4. Thus, when water is added to the fuel tank 1, the water pump 73 can pump water into the fuel tank 1 through the water injection pipe 7, the first pipe 3, the second pipe 4, and the connecting pipe 9. When water is drained from the fuel tank 1, the submersible pump 6 can discharge the water in the tank through the third pipe 5, the second pipe 4, the first pipe 3, and the drain pipe 8.

[0036] In this embodiment, preferably, as follows: Figure 3 As shown, a second pressure gauge 91 and a third shut-off valve 92 are installed on the connecting pipe 9. The second pressure gauge 91 can monitor the pressure of the fuel tank 1 during the water pressure test. The third shut-off valve 92 can close the connecting pipe 9. When water is injected into the fuel tank 1, the third shut-off valve 92 is opened to open the connecting pipe 9, so that water from the second pipe 4 can flow into the fuel tank 1 through the connecting pipe 9. When draining the fuel tank 1, the third shut-off valve 92 is closed so that the water discharged through the third pipe 5 can be discharged smoothly through the second pipe 4, and will not return to the fuel tank 1 through the connecting pipe 9.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A drain system for an LNG fuel tank, characterized by, This includes the first pipe, the second pipe, the third pipe, the submersible pump, the water injection pipe, and the drainage pipe; The first pipe is used to be fixed vertically to an auxiliary structure on one side of the fuel tank. The upper end of the first pipe extends to the top of the fuel tank, and the upper end of the first pipe is connected to the top of the fuel tank through the second pipe. The submersible pump is installed inside the fuel tank and arranged at the bottom of the fuel tank, and the outlet of the submersible pump is connected to the second pipe through the third pipe; The lower end of the first pipe extends to the bottom of the fuel tank. The lower end of the first pipe has a first interface and a second interface. The first interface is used to connect to the water injection pipe, and the second interface is used to connect to the drainage pipe.

2. The drain system of the LNG fuel tank according to claim 1, wherein The LNG fuel tank's injection and drainage system also includes a water injection pump; The water injection pipeline is connected to an external water source via the water injection pump.

3. The LNG fuel tank injection and drainage system according to claim 1, characterized in that, A check valve and a first shut-off valve are installed sequentially along the flow direction on the water injection pipe. Alternatively, a shut-off check valve may be installed on the water injection pipeline.

4. The drain system of the LNG fuel tank according to claim 1, wherein A second shut-off valve is installed on the drainage pipe.

5. The drain system of the LNG fuel tank according to claim 1, wherein A first pressure gauge is installed on the water injection pipe.

6. The drain system of the LNG fuel tank according to claim 2, wherein Both the first pipe and the water injection pipe are rigid pipes; The water inlet of the water pump is connected to a fire-fighting suction hose, and the water is connected to an external water source through the fire-fighting suction hose.

7. The drain system of the LNG fuel tank according to claim 1, wherein The second pipe is a fire hose.

8. The drain system of the LNG fuel tank according to claim 1, wherein The fuel tank is provided with a first inlet port on its top, and a connecting pipe is installed at the first inlet port. One end of the connecting pipe is connected to the fuel tank, and the other end of the connecting pipe forms a third interface, which is connected to the second pipe.

9. The drain system of the LNG fuel tank according to claim 8, wherein The connecting pipe has a third interface at one end and a fourth interface at the other end, which is connected to the third pipe.

10. The drain system of the LNG fuel tank according to claim 8, wherein A second pressure gauge and a third shut-off valve are installed on the connecting pipe.

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