Natural gas liquefaction device

Abstract

The invention provides a natural gas liquefaction device, and aims to solve the technical problem of poor applicability of BOG liquefaction equipment. The liquefying device comprises: a recovery assembly, which is internally provided with a liquefying chamber, and the bottom of the liquefying chamber is provided with a return pipe; one end of the connecting pipeline is communicated with the liquefaction cavity and BOG generation equipment, and the other end of the connecting pipeline penetrates into the recovery assembly and is communicated with the liquefaction cavity; the heat exchange assembly comprises a refrigeration part and a heat exchange part, the refrigeration part is arranged in the liquefaction cavity, and the heat exchange part is located outside the recovery assembly; wherein the end, far away from the liquefaction cavity, of the return pipe is located below the liquid level of liquefied natural gas in the BOG generation equipment, the end, far away from the liquefaction cavity, of the connecting pipeline is located above the liquid level of the liquefied natural gas in the BOG generation equipment, and a check valve is arranged on the return pipe. The liquefaction device has the advantage of being suitable for BOG recovery liquefaction work in various scenes.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas processing, and particularly to a liquefaction device for natural gas. Background Art

[0002] After natural gas is liquefied, it needs to be stored through storage equipment. During production, transportation and other processes, even if the heat insulation measures are very good, the liquefied natural gas will still inevitably absorb heat from the environment and thus vaporize again. The natural gas gas that evaporates again is called BOG. The evaporated natural gas volatilizes into the environment, on the one hand, it will directly pollute the atmosphere, and on the other hand, it will cause waste of resources.

[0003] Therefore, there are liquefaction devices designed and produced for BOG, which liquefy the BOG generated during production, transportation and other processes again and recycle and store it.

[0004] However, the applicability of the liquefaction devices in the prior art is poor. For example, the patent document with the publication number CN111295559A only recovers the BOG generated in the storage tank. Summary of the Invention

[0005] Aiming at the technical problem of poor applicability of the existing BOG liquefaction equipment, the present invention provides a liquefaction device for natural gas, which has the advantage of being applicable to the BOG recovery and liquefaction work in various scenarios.

[0006] The technical solution of the present invention is as follows: A liquefaction device for natural gas, comprising: A recovery component, which has a liquefaction chamber inside, and a reflux pipe is provided at the bottom of the liquefaction chamber; A connecting pipe, one end of which is communicated with the BOG generating equipment through the liquefaction chamber, and the other end penetrates into the recovery component and is communicated with the liquefaction chamber; A heat exchange component, which includes a refrigeration part and a heat exchange part. The refrigeration part is arranged inside the liquefaction chamber, and the heat exchange part is located outside the recovery component; Wherein, the end of the reflux pipe far away from the liquefaction chamber is located below the liquefied natural gas liquid level in the BOG generating equipment, the end of the connecting pipe far away from the liquefaction chamber is located above the liquefied natural gas liquid level in the BOG generating equipment, and a check valve is provided on the reflux pipe.

[0007] Optionally, the recovery component includes: A housing, the inner wall of which is provided with a heat insulation layer, and the bottom of which has through holes for the reflux pipe and the connecting pipe to pass through; An inner liner, which is arranged at the top inside the housing, and the inside of the inner liner is the liquefaction chamber, and the top of the inner liner is open; Among them, the heat exchange component is arranged at the opening at the top of the inner tank, and the heat exchange component is hermetically connected to the housing.

[0008] Optionally, the bottom of the inner tank is a funnel-shaped structure, and the end of the return pipe is arranged at the bottom of the funnel-shaped structure.

[0009] Optionally, the heat exchange component includes: A circulation pipe, a part of which is located in the liquefaction chamber, constituting the refrigeration part. The circulation pipe is filled with a heat exchange medium, and the other part of the circulation pipe is located in the heat exchange part; An exchange pipe, arranged in the heat exchange part. The exchange pipe is sleeved outside the circulation pipe, and one end of the circulation pipe is connected to the output end of the refrigeration component; Among them, a pump body is respectively arranged on the circulation pipe and the exchange pipe.

[0010] Optionally, the circulation pipe is a copper pipe, and the outside of the exchange pipe is wrapped with a heat insulation layer.

[0011] Optionally, a part of the circulation pipe located in the liquefaction chamber has a long strip-shaped flat cross-section structure.

[0012] Optionally, the refrigeration component can be a vapor compression refrigeration device; A part of the circulation pipe located in the liquefaction chamber is an S-shaped structure, and the exchange pipe is spirally wound around a purification tank.

[0013] Optionally, one end of the connecting pipe away from the recovery component is connected to the top of the purification tank, and the bottom of the purification tank is connected to the LNG storage device through a conduit.

[0014] Optionally, the inner diameter of the exchange pipe is greater than or equal to 1.5 times the outer diameter of the circulation pipe, and the exchange pipe and the circulation pipe are coaxially arranged.

[0015] Optionally, a plurality of inclined flow disturbing plates are arranged between the inner wall of the exchange pipe and the outer wall of the circulation pipe.

[0016] Compared with the prior art, the beneficial effects of the present invention are: A liquefaction chamber is arranged in the recovery component, and the refrigeration part of the heat exchange component is arranged in the liquefaction chamber. Then, the BOG generating device is connected to the liquefaction chamber through a connecting pipe, so that the generated BOG is liquefied again in the liquefaction chamber, and the liquefied BOG becomes liquid LNG and flows back to the BOG generating device through the return pipe. In this technical solution, the BOG generating device is mainly connected through the connecting pipe, and at the same time, the heat exchange component and the liquefaction chamber can be moved to any position. Therefore, the liquefaction device in this technical solution has the characteristic of wide application range. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic structural diagram of the present invention; Figure 2 It is a schematic structural diagram of the heat exchange component. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In the following, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present invention. Therefore, the drawings and the description are considered to be exemplary in nature rather than restrictive.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present invention is usually placed, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0021] The embodiments of the present invention will be described in detail below with reference to the drawings.

[0022] Embodiment: Refer to Figure 1 and Figure 2, A liquefaction device for natural gas, comprising a recovery component 1, a reflux pipe 2, a connecting pipe 3 and a heat exchange component 4. Among them, a liquefaction chamber 11 is provided inside the recovery component 1, and a reflux pipe 2 is connected to the bottom of the liquefaction chamber 11. One end of the connecting pipe 3 penetrates into the recovery component 1 and communicates with the liquefaction chamber 11. In addition, the other end of the reflux pipe 2 and the other end of the connecting pipe 3 are both connected to the BOG generating device, wherein the end of the reflux pipe 2 is submerged below the liquid level of the liquefied natural gas, and the end of the connecting pipe 3 is located at the top of the BOG generating device and there is a spacing from the liquid level of the liquefied natural gas. In order to prevent the liquefied natural gas from flowing back in the reflux pipe 2, a check valve is provided on the reflux pipe 2.

[0023] The heat exchange component 4 includes a refrigeration part 41 and a heat exchange part 42, wherein the refrigeration part 41 is located inside the liquefaction chamber 11, and the heat exchange part 42 is located outside the recovery component 1.

[0024] The working principle of this embodiment is that a liquefaction chamber 11 is provided inside the recovery component 1, and the refrigeration part 41 of the heat exchange component 4 is arranged inside the liquefaction chamber 11. Then, the BOG generating device is connected to the liquefaction chamber 11 through the connecting pipe 3, so that the generated BOG is liquefied again in the liquefaction chamber 11, and the liquefied BOG becomes liquid LNG and flows back into the BOG generating device through the reflux pipe 2. In this embodiment, the BOG generating device is mainly connected through the connecting pipe 3, and at the same time, the heat exchange component 4 and the liquefaction chamber 11 can be moved to any position. Therefore, the liquefaction device in this embodiment has the characteristic of a wide application range.

[0025] In one specific embodiment: The recovery component 1 includes a housing 12 and an inner liner 13. Specifically, a heat insulation layer is provided on the inner wall of the housing 12, and two through holes are provided at the bottom of the housing 12 for the reflux pipe 2 and the connecting pipe 3 to pass through respectively.

[0026] The inner liner 13 is arranged at the top inside the housing 12, and the inside of the inner liner 13 is the above-mentioned liquefaction chamber 11. The top of the inner liner 13 is an open structure, and the top of the housing 12 has a hollow structure corresponding to the open structure at the top of the inner liner 13. The refrigeration part 41 of the above-mentioned heat exchange component 4 penetrates into the liquefaction chamber 11 through the hollow structure of the housing 12 and the open structure of the inner liner 13.

[0027] Preferably, the bottom of the inner liner 13 is a funnel-shaped structure, and the end of the reflux pipe 2 is arranged at the bottom of the funnel-shaped structure. By setting the bottom of the inner liner 13 as a funnel-shaped structure, it is convenient to converge the liquefied natural gas and make the liquefied natural gas flow into the reflux pipe 2.

[0028] Among them, the top of the housing 12 is detachably and fixedly connected to the heat exchange assembly 4, and heat insulation material and sealing material are provided at the connection, so that the heat exchange assembly 4 and the housing 12 are in a sealed connection state.

[0029] In this embodiment, by providing the housing 12, on the one hand, the inner tank 13 is protected by the housing 12, and on the other hand, by providing the housing 12, it is convenient to move the device. Therefore, in order to further improve the flexibility of the housing 12, a number of self-locking universal wheels 14 are provided at the bottom of the housing 12.

[0030] In another specific embodiment: The heat exchange assembly 4 includes a circulation pipe 43 and an exchange pipe 44. Specifically, a part of the circulation pipe 43 is located in the liquefaction chamber 11, and a part of the circulation pipe 43 located in the liquefaction chamber 11 forms the refrigeration part 41 of the heat exchange assembly 4, and the other part of the circulation pipe 43 is located in the heat exchange part 42. The inside of the circulation pipe 43 has a heat exchange medium, and the heat exchange medium is generally pure water or hot oil.

[0031] The exchange pipe 44 is arranged in the heat exchange part 42, the exchange pipe 44 is sleeved on the circulation pipe 43, and the extending direction of the circulation pipe 43 is the same as that of the exchange pipe 44. The inner dimension of the exchange pipe 44 is larger than the outer dimension of the circulation pipe 43, so that there is a gap between the outer wall of the circulation pipe 43 and the inner wall of the exchange pipe 44.

[0032] One end of the exchange pipe 44 is connected to the output end of the refrigeration component, and the refrigeration component can be a common refrigeration device such as a vapor compression refrigeration device, a vapor absorption refrigeration device, or a vapor jet refrigeration device.

[0033] Generally, a pump body is respectively provided on the circulation pipe 43 and the exchange pipe 44. The circulation pipe 43 drives the heat exchange medium inside it through the pump body, and the exchange pipe 44 drives the cold medium inside it through the pump body.

[0034] In this embodiment, by providing the exchange pipe 44, the heat exchange assembly 4 can be applicable to a variety of different refrigeration devices, and then by arranging the circulation pipe 43 inside the exchange pipe 44, the heat exchange efficiency between the circulation pipe 43 and the exchange pipe 44 is improved.

[0035] Preferably, the circulation pipe 43 is a copper pipe, and the outside of the exchange pipe 44 is wrapped with a heat insulation layer.

[0036] In another specific embodiment: In order to increase the heat exchange efficiency of the circulation pipe 43 in the liquefaction chamber 11, a part of the circulation pipe 43 located in the liquefaction chamber 11 is set as an S-shaped structure, and a part of the circulation pipe 43 located in the liquefaction chamber 11 is set as a flat structure with a long strip-shaped cross-section. Thereby, the contact area between the circulation pipe 43 and the BOG in the liquefaction chamber 11 is increased, and the heat exchange efficiency is improved.

[0037] In another specific embodiment: The exchange pipe 44 is spirally wound around a purification tank 45. One end of the connecting pipe 3 away from the recovery assembly 1 is connected to the top of the purification tank 45, and the bottom of the purification tank 45 is connected to the LNG storage device through a conduit.

[0038] In this embodiment, the condensed BOG in the connecting pipe 3 can be collected in advance, thereby reducing the waste of the cold quantity of the circulation pipe 43.

[0039] In another specific embodiment: Both the exchange pipe 44 and the circulation pipe 43 are circular pipes. The inner diameter of the exchange pipe 44 is greater than or equal to 1.5 times the outer diameter of the circulation pipe 43, and the exchange pipe 44 and the circulation pipe 43 are coaxially arranged. A plurality of inclined flow disturbing plates are arranged between the inner wall of the exchange pipe 44 and the outer wall of the circulation pipe 43.

[0040] In this embodiment, by arranging a plurality of flow disturbing plates on the inner wall of the exchange pipe 44, the flow velocity of the cold medium in the exchange pipe 44 can be reduced, thereby improving the heat exchange efficiency between the exchange pipe 44 and the circulation pipe 43.

[0041] The above-described embodiments only represent the specific implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A liquefaction device for natural gas, characterized in that, Comprising: A recovery component with a liquefaction chamber inside, and a reflux pipe is provided at the bottom of the liquefaction chamber; A connecting pipe, one end of which is communicated with the liquefaction chamber and the BOG generating device, and the other end penetrates into the recovery component and is communicated with the liquefaction chamber; A heat exchange component, which includes a refrigeration part and a heat exchange part, the refrigeration part is arranged inside the liquefaction chamber, and the heat exchange part is located outside the recovery component; Wherein, one end of the reflux pipe away from the liquefaction chamber is below the liquefied natural gas liquid level in the BOG generating device, one end of the connecting pipe away from the liquefaction chamber is above the liquefied natural gas liquid level in the BOG generating device, and a check valve is provided on the reflux pipe.

2. The natural gas liquefaction device according to claim 1, characterized in that, The recovery component includes: A housing, the inner wall of which is provided with a heat insulation layer, and its bottom has through holes for the reflux pipe and the connecting pipe to pass through; An inner liner, arranged at the top inside the housing, the inside of the inner liner is the liquefaction chamber, and the top of the inner liner is open; Wherein, the heat exchange component is arranged at the opening at the top of the inner liner, and the heat exchange component is hermetically connected with the housing.

3. The liquefaction device for natural gas according to claim 2, characterized in that The bottom of the inner liner is of a funnel-shaped structure, and the end of the reflux pipe is arranged at the bottom of the funnel-shaped structure.

4. The liquefaction device for natural gas according to claim 1, characterized in that, The heat exchange component includes: A circulation pipe, a part of which is located inside the liquefaction chamber to form the refrigeration part, a heat exchange medium is provided inside the circulation pipe, and the other part of the circulation pipe is located inside the heat exchange part; An exchange pipe, arranged inside the heat exchange part, the exchange pipe is sleeved outside the circulation pipe, and one end of the circulation pipe is connected to the output end of the refrigeration component; Wherein, a pump body is respectively provided on the circulation pipe and the exchange pipe.

5. The liquefaction device for natural gas according to claim 4, characterized in that The circulation pipe is a copper pipe, and the outside of the exchange pipe is wrapped with a heat insulation layer.

6. The liquefaction device for natural gas according to claim 4, characterized in that The cross-section of the part of the circulation pipe located inside the liquefaction chamber is a long strip-shaped flat structure.

7. The liquefaction device for natural gas according to claim 4, characterized in that The refrigeration component can be a steam compression refrigeration device; The part of the circulation pipe located inside the liquefaction chamber is of an S-shaped structure, and the exchange pipe is spirally wound around a purification tank.

8. The liquefaction device for natural gas according to claim 7, characterized in that One end of the connecting pipe away from the recovery component is connected to the top of the purification tank, and the bottom of the purification tank is connected to the LNG storage device through a conduit.

9. The liquefaction device for natural gas according to claim 4, characterized in that The inner diameter of the exchange pipe is greater than or equal to 1.5 times the outer diameter of the circulation pipe, and the exchange pipe and the circulation pipe are coaxially arranged.

10. The liquefaction device for natural gas according to claim 9, characterized in that A number of inclined flow disturbing plates are arranged between the inner wall of the exchange pipe and the outer wall of the circulation pipe.

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