Ship unloading system with LNG and LPG sharing ship unloading arm

Abstract

The invention discloses a ship unloading system with LNG and LPG sharing ship unloading arms, comprising: a ship unloading arm assembly comprising a ship unloading liquid-phase arm assembly and a ship unloading gas-phase arm, the ship unloading liquid-phase arm assembly comprising a ship unloading gas / liquid-phase arm, a first ship unloading liquid-phase arm and a second ship unloading liquid-phase arm; the matched header pipe assembly comprises a ship unloading liquid phase branch pipe assembly, a ship unloading liquid phase header pipe, a ship unloading gas phase pipeline, an LNG ship unloading liquid phase pipeline, an LPG ship unloading liquid phase pipeline, an LNG ship unloading gas phase branch pipe and an LPG ship unloading gas phase branch pipe, and the ship unloading liquid phase branch pipe assembly comprises a first ship unloading liquid phase branch pipe, a second ship unloading liquid phase branch pipe and a third ship unloading liquid phase branch pipe. When facing an LNG ship or an LPG ship, the independent unshipped LNG or LPG is conveyed to the corresponding LNG storage system or LPG storage system to be stored by sharing one unshipping arm assembly by switching the corresponding pipelines in the matched header pipe assembly, so that the cost is reduced, the operation process is simplified, and the operation stability of a factory is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of petrochemical industry, and particularly to a ship unloading system that shares a ship unloading arm for LNG and LPG. Background Art

[0002] LNG (liquefied natural gas) is a high-quality energy source with wide applications. Due to its characteristics such as high calorific value, high efficiency, and low pollution, it is widely used in various fields of national economy and people's livelihood, and its energy proportion is gradually increasing. Ship unloading is the main product source of an LNG receiving terminal. The LNG in the transport ship is transported to the LNG storage tank through the ship unloading arm and the ship unloading main pipe for storage, and then the peak shaving function of the receiving terminal is realized.

[0003] LPG (liquefied petroleum gas) is an important raw material for many chemical products. Atmospheric pressure low-temperature storage tanks are an important means for storing LPG. The ship unloading arm is also required to transport LPG from the transport ship to the LPG storage tank.

[0004] With the development of the energy and chemical industries, the functions and product types of chemical plants and LNG receiving terminals are gradually increasing, and more raw materials are needed. The demand for factories to simultaneously have the functions of receiving and storing LNG and LPG by ship will gradually increase. If according to the existing process, two sets of ship unloading systems need to be set up to separately realize the ship unloading operations of LNG and LPG. This solution not only increases the investment in the terminal land occupation, the number of ship unloading arm equipment, pipes, etc., but also makes the process flow more complex, which has an adverse impact on the operation during operation.

[0005] Based on the above background, the present invention provides a ship unloading system that shares a ship unloading arm for LNG and LPG, which not only saves the investment in projects such as terminals and equipment, but also simplifies the operation process and improves the stability of the factory operation. Summary of the Invention

[0006] In view of the above problems, the present invention is proposed to provide a ship unloading system that shares a ship unloading arm for LNG and LPG, which can overcome or at least partially solve the above problems.

[0007] The present invention provides a ship unloading system that shares a ship unloading arm for LNG and LPG, and the ship unloading system that shares a ship unloading arm for LNG and LPG includes:

[0008] A ship unloading arm assembly, including a ship unloading liquid phase arm assembly and a ship unloading gas phase arm. The ship unloading liquid phase arm assembly includes a ship unloading gas / liquid phase arm, a first ship unloading liquid phase arm, and a second ship unloading liquid phase arm that are arranged in parallel.

[0009] The supporting main pipe assembly includes a ship unloading liquid phase branch pipe assembly, a ship unloading liquid phase main pipe, a ship unloading gas phase pipeline, an LNG ship unloading liquid phase pipeline, an LPG ship unloading liquid phase pipeline, an LNG ship unloading gas phase branch pipe, and an LPG ship unloading gas phase branch pipe. The ship unloading liquid phase branch pipe assembly includes a first ship unloading liquid phase branch pipe, a second ship unloading liquid phase branch pipe, and a third ship unloading liquid phase branch pipe. Among them, an LNG ship unloading liquid phase cut-off valve is provided on the LNG ship unloading liquid phase pipeline, an LPG ship unloading liquid phase cut-off valve is provided on the LPG ship unloading liquid phase pipeline, an LNG ship unloading gas phase cut-off valve is provided on the LNG ship unloading gas phase branch pipe, and an LPG ship unloading gas phase cut-off valve is provided on the LPG ship unloading gas phase branch pipe;

[0010] An LNG storage system for storing LNG;

[0011] An LPG storage system for storing LPG;

[0012] Among them, the first ship unloading liquid phase arm is connected to the ship unloading liquid phase main pipe through the first ship unloading liquid phase branch pipe; the second ship unloading liquid phase arm is connected to the ship unloading liquid phase main pipe through the second ship unloading liquid phase branch pipe; the ship unloading gas / liquid phase arm is connected to the ship unloading liquid phase main pipe and the ship unloading gas phase pipeline respectively through the third ship unloading liquid phase branch pipe; the ship unloading gas phase arm is connected to the LPG ship unloading gas phase branch pipe through the ship unloading gas phase pipeline, and the LPG ship unloading gas phase branch pipe is connected to the LPG storage system; the ship unloading liquid phase main pipe is connected to the LNG storage system through the LNG ship unloading liquid phase pipeline, and the ship unloading liquid phase main pipe is connected to the LPG storage system through the LPG ship unloading liquid phase pipeline; the LNG ship unloading gas phase branch pipe is connected between the LNG storage system and the ship unloading gas phase pipeline.

[0013] Optionally, an LNG ship unloading cold circulation pipeline is connected to the LNG storage system. The LNG ship unloading cold circulation pipeline is connected to the ship unloading liquid phase main pipe through the LNG to common ship unloading main pipe cold insulation circulation pipeline. An LNG cold circulation cut-off valve and an LNG ship unloading cold circulation manual valve are provided on the LNG ship unloading cold circulation pipeline.

[0014] Optionally, an LPG ship unloading cold circulation pipeline is connected to the LPG storage system. The LPG ship unloading cold circulation pipeline is connected to the ship unloading liquid phase main pipe through the LPG to common ship unloading main pipe cold insulation circulation pipeline. An LPG cold circulation cut-off valve and an LPG ship unloading cold circulation manual valve are provided on the LPG ship unloading cold circulation pipeline.

[0015] Optionally, a first nitrogen purging pipeline is provided at the connection between the first ship unloading liquid phase branch pipe and the first ship unloading liquid phase arm, and a first temperature sensor, a first pressure sensor, and a first cut-off valve for the ship unloading liquid phase branch pipe are respectively provided on the first ship unloading liquid phase branch pipe.

[0016] Optionally, a second nitrogen purge pipeline is provided at the connection between the second liquid unloading branch pipe and the second liquid unloading liquid arm, and a second temperature sensor, a second pressure sensor, and a second cut-off valve for the liquid unloading branch pipe are respectively provided on the second liquid unloading branch pipe.

[0017] Optionally, a third nitrogen purge pipeline is provided at the connection between the third liquid unloading branch pipe and the unloading gas / liquid arm, and a third temperature sensor, a third pressure sensor, and a third cut-off valve for the liquid unloading branch pipe are respectively provided on the third liquid unloading branch pipe.

[0018] Optionally, a fourth nitrogen purge pipeline is provided at the connection between the unloading gas pipeline and the unloading gas arm, a fourth temperature sensor and a fourth pressure sensor are respectively provided on the unloading gas pipeline, and an LPG unloading gas cut-off valve is provided on the LPG unloading gas branch pipe.

[0019] Optionally, a return gas pressure regulating valve for unloading is further provided on the unloading gas pipeline, and fifth pressure sensors are connected to both ends of the return gas pressure regulating valve for unloading.

[0020] Optionally, an LNG unloading main pipe drainage pipeline is communicatively connected to the LNG unloading liquid pipeline, the other end of the LNG unloading main pipe drainage pipeline is communicatively connected to the liquid unloading main pipe, and an LNG unloading drainage valve is provided on the LNG unloading main pipe drainage pipeline.

[0021] Optionally, an LPG unloading main pipe drainage pipeline is communicatively connected to the LPG unloading liquid pipeline, the other end of the LPG unloading main pipe drainage pipeline is communicatively connected to the liquid unloading main pipe, and an LPG unloading drainage valve is provided on the LPG unloading main pipe drainage pipeline.

[0022] The technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0023] In the unloading system with a shared unloading arm for LNG and LPG according to the embodiments of the present invention, when facing an LNG ship or an LPG ship, by switching the corresponding pipelines in the supporting main pipe assembly respectively, a set of shared unloading arm assemblies are realized, and the independently unloaded LNG or LPG is transported to the corresponding LNG storage system or LPG storage system for storage, which not only reduces the cost, simplifies the operation process, but also improves the stability of the plant operation.

[0024] The above description is only an overview of the technical solutions of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features, and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are specifically described below. Description of the Drawings

[0025] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for the purpose of showing the preferred embodiments and are not to be considered as limiting the present invention. Also, throughout the drawings, the same reference numerals are used to represent the same components.

[0026] In the drawings:

[0027] Figure 1 is a schematic diagram of the principle structure of a ship unloading system for a shared ship unloading arm of LNG and LPG provided by an embodiment of the present invention.

[0028] Description of reference numerals:

[0029] L01A - First ship unloading liquid phase arm; L01B - Ship unloading gas / liquid phase arm; L01C - Second ship unloading liquid phase arm; L02 - Ship unloading gas phase arm; S01A - First ship unloading liquid phase branch pipe; S01B - Third ship unloading liquid phase branch pipe; S01C - Second ship unloading liquid phase branch pipe; S02 - Ship unloading gas phase pipeline; S03 - Ship unloading liquid phase main pipe; S11 - LNG ship unloading liquid phase pipeline; S12 - LNG ship unloading gas phase branch pipe; S13 - LNG ship unloading cold circulation pipeline; S14 - LNG to shared ship unloading main pipe cold insulation circulation pipeline; S15 - LNG ship unloading main pipe drainage pipeline; S21 - LPG ship unloading liquid phase pipeline; S22 - LPG ship unloading gas phase branch pipe; S23 - LPG ship unloading cold circulation pipeline; S24 - LPG to shared ship unloading main pipe cold insulation circulation pipeline; S25 - LPG ship unloading main pipe drainage pipeline; XV1 - First cut-off valve for ship unloading liquid phase branch pipe; XV2 - Third cut-off valve for ship unloading liquid phase branch pipe; XV3 - Second cut-off valve for ship unloading liquid phase branch pipe; XV4 - LNG ship unloading liquid phase cut-off valve; XV5 - LPG ship unloading liquid phase cut-off valve; XV6 - LNG ship unloading gas phase cut-off valve; XV7 - LPG ship unloading gas phase cut-off valve; XV8 - LNG cold circulation cut-off valve; XV9 - LPG cold circulation cut-off valve; XV10 - First nitrogen purge pipeline; XV11 - Third nitrogen purge pipeline; XV12 - Second nitrogen purge pipeline; XV13 - Fourth nitrogen purge pipeline; MV1 - LNG ship unloading drainage valve; MV2 - LPG ship unloading drainage valve; MV3 - LNG ship unloading cold circulation manual valve; MV4 - LPG ship unloading cold circulation manual valve; PCV1 - Ship unloading return gas pressure regulating valve; P1 - First pressure sensor; P2 - Second pressure sensor; P3 - Third pressure sensor; P3 - Fourth pressure sensor; P5 - Fifth pressure sensor; T1 - First temperature sensor; T2 - Second temperature sensor; T3 - Third temperature sensor; T4 - Fourth temperature sensor. Detailed embodiments

[0030] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the drawings.

[0031] Various structural schematic diagrams according to embodiments of the present disclosure are shown in the accompanying drawings. These figures are not drawn to scale, where certain details are enlarged for the purpose of clear expression, and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art can additionally design regions / layers with different shapes, sizes, and relative positions according to actual requirements.

[0032] In the context of the present disclosure, when a layer / component is referred to as being "on" another layer / component, the layer / component can be directly on the other layer / component, or there can be an intermediate layer / component between them. Additionally, if a layer / component is "on" another layer / component in one orientation, then when the orientation is reversed, the layer / component can be "under" the other layer / component. In the context of the present disclosure, similar or identical components may be denoted by the same or similar reference numerals.

[0033] To better understand the above technical solutions, the above technical solutions will be described in detail below in conjunction with specific embodiments. It should be understood that the embodiments of the present disclosure content and the specific features in the embodiments are detailed descriptions of the technical solutions of the present application, rather than limitations on the technical solutions of the present application. Without conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0034] Figure 1 is a flowchart of a ship unloading system for a common ship unloading arm of LNG and LPG provided by an embodiment of the present invention, as Figure 1 shown, the ship unloading system for the common ship unloading arm of LNG and LPG includes: a ship unloading arm assembly, a supporting main pipe assembly, an LNG storage system, and an LPG storage system; the ship unloading arm assembly includes a ship unloading liquid phase arm assembly and a ship unloading gas phase arm L02, and the ship unloading liquid phase arm assembly includes a ship unloading gas / liquid phase arm L01B, a first ship unloading liquid phase arm L01A, and a second ship unloading liquid phase arm L01C that are arranged in parallel; the supporting main pipe assembly includes a ship unloading liquid phase branch pipe assembly, a ship unloading liquid phase main pipe S03, a ship unloading gas phase pipeline S02, an LNG ship unloading liquid phase pipeline S11, and an LPG ship unloading liquid phase pipeline S21, and the ship unloading liquid phase branch pipe assembly includes a first ship unloading liquid phase branch pipe S01A, a second ship unloading liquid phase branch pipe S01C, and a third ship unloading liquid phase branch pipe S01B; the LNG storage system is used to store LNG; the LPG storage system is used to store LPG;

[0035] Among them, the first liquid unloading liquid phase arm L01A is communicated with the liquid unloading liquid phase main pipe S03 through the first liquid unloading liquid phase branch pipe S01A; the second liquid unloading liquid phase arm L01C is communicated with the liquid unloading liquid phase main pipe S03 through the second liquid unloading liquid phase branch pipe S01C; the liquid unloading gas / liquid phase arm L01B is communicated with the liquid unloading liquid phase main pipe S03 and the liquid unloading gas phase pipeline S02 respectively through the third liquid unloading liquid phase branch pipe S01B; the liquid unloading gas phase arm L02 is communicated with the LPG liquid unloading gas phase branch pipe S22 through the liquid unloading gas phase pipeline S02, and the LPG liquid unloading gas phase branch pipe S22 is communicated with the LPG storage system; the liquid unloading liquid phase main pipe S03 is communicated with the LNG storage system through the LNG liquid unloading liquid phase pipeline S11, and the liquid unloading liquid phase main pipe S03 is communicated with the LPG storage system through the LPG liquid unloading liquid phase pipeline S21.

[0036] Optionally, an LNG liquid unloading gas phase branch pipe S12 is connected between the LNG storage system and the liquid unloading gas phase pipeline S02, and an LNG liquid unloading gas phase cut-off valve XV6 is arranged on the LNG liquid unloading gas phase branch pipe S12, and the LNG liquid unloading gas phase cut-off valve XV6 is used to control the on-off of the LNG liquid unloading gas phase branch pipe S12; an LPG liquid unloading gas phase cut-off valve XV7 is arranged on the LPG liquid unloading gas phase branch pipe S22, and the LPG liquid unloading gas phase cut-off valve XV7 is used to control the on-off of the LPG liquid unloading gas phase branch pipe S22; an LNG liquid unloading liquid phase cut-off valve XV4 is arranged on the LNG liquid unloading liquid phase pipeline S11, and the LNG liquid unloading liquid phase cut-off valve XV4 is used to control the on-off of the LNG liquid unloading liquid phase pipeline S11; an LPG liquid unloading liquid phase cut-off valve XV5 is arranged on the LPG liquid unloading liquid phase pipeline S21, and the LPG liquid unloading liquid phase cut-off valve XV5 is used to control the on-off of the LPG liquid unloading liquid phase pipeline S21.

[0037] When the LNG and LPG shared liquid unloading arm unloading system in the embodiment of the present invention faces an LNG ship or an LPG ship, by switching the corresponding pipelines in the supporting main pipe assembly respectively, it realizes sharing a set of liquid unloading arm assembly, and transports the independently unloaded LNG or LPG to the corresponding LNG storage system or LPG storage system for storage. This not only saves project investments such as wharves and equipment, reduces costs, but also simplifies the operation process and improves the stability of the plant operation.

[0038] Before the LNG ship or LPG ship berths, it is possible to choose to use the existing LNG or LPG to perform a cold circulation on the pipeline to maintain the cold state. Optionally, the LNG storage system is connected with an LNG ship unloading cold circulation pipeline S13, and the LNG ship unloading cold circulation pipeline S13 is connected to the ship unloading liquid phase main pipeline S03 through an LNG to common ship unloading main pipe cold insulation circulation pipeline S14. An LNG cold circulation cut-off valve XV8 and an LNG ship unloading cold circulation manual valve MV3 are arranged on the LNG ship unloading cold circulation pipeline S13; the LPG storage system is connected with an LPG ship unloading cold circulation pipeline S23, and the LPG ship unloading cold circulation pipeline S23 is connected to the ship unloading liquid phase main pipeline S03 through an LPG to common ship unloading main pipe cold insulation circulation pipeline S24. An LPG cold circulation cut-off valve XV9 and an LPG ship unloading cold circulation manual valve MV4 are arranged on the LPG ship unloading cold circulation pipeline S23. In the embodiment of the present invention, by arranging the LNG ship unloading cold circulation pipeline S13 and the LPG ship unloading cold circulation pipeline S23 to connect the ship unloading liquid phase main pipeline S03 with the LNG storage system and the LPG storage system respectively, the stored LNG or LPG can be utilized to perform a cold circulation on the system pipeline to maintain the cold state. At the same time, corresponding valves are arranged to control the opening or closing of the corresponding pipelines, so as to realize flexible line switching.

[0039] After the LNG or LPG ship unloading operation is completed, in order to achieve the draining and purging of the pipeline, the embodiment of the present invention also arranges corresponding nitrogen purging pipelines and draining pipelines. Specifically:

[0040] A first nitrogen purging pipeline XV10 is arranged at the connection between the first ship unloading liquid phase branch pipe S01A and the first ship unloading liquid phase arm L01A, and a first temperature sensor T1, a first pressure sensor P1 and a first cut-off valve XV1 for the ship unloading liquid phase branch pipe are respectively arranged on the first ship unloading liquid phase branch pipe S01A. The first nitrogen purging pipeline XV10 is used to purge the LNG remaining at the connection between the first ship unloading liquid phase branch pipe S01A and the first ship unloading liquid phase arm L01A. The first temperature sensor T1 and the first pressure sensor P1 are respectively used to detect the temperature and pressure in the first ship unloading liquid phase branch pipe S01A. The first cut-off valve XV1 for the ship unloading liquid phase branch pipe is used to control the on-off of the first ship unloading liquid phase branch pipe S01A.

[0041] A second nitrogen purge pipeline XV12 is provided at the connection between the second ship-unloading liquid-phase branch pipe S01C and the second ship-unloading liquid-phase arm L01C. A second temperature sensor T2, a second pressure sensor P2, and a second cut-off valve XV3 for the ship-unloading liquid-phase branch pipe are respectively arranged on the second ship-unloading liquid-phase branch pipe S01C. The second nitrogen purge pipeline XV12 is used to purge the LNG remaining at the connection between the second ship-unloading liquid-phase branch pipe S01C and the second ship-unloading liquid-phase arm L01C. The second temperature sensor T2 and the second pressure sensor P2 are respectively used to detect the temperature and pressure in the second ship-unloading liquid-phase branch pipe S01C. The second cut-off valve XV3 for the ship-unloading liquid-phase branch pipe is used to control the on-off of the second ship-unloading liquid-phase branch pipe S01C.

[0042] A third nitrogen purge pipeline XV11 is provided at the connection between the third ship-unloading liquid-phase branch pipe S01B and the ship-unloading gas / liquid-phase arm L01B. A third temperature sensor T3, a third pressure sensor P3, and a third cut-off valve XV2 for the ship-unloading liquid-phase branch pipe are respectively arranged on the third ship-unloading liquid-phase branch pipe S01B. The third nitrogen purge pipeline XV11 is used to purge the remaining LNG or LPG at the connection between the third ship-unloading liquid-phase branch pipe S01B and the ship-unloading gas / liquid-phase arm L01B. The third temperature sensor T3 and the third pressure sensor P3 are respectively used to detect the temperature and pressure in the third ship-unloading liquid-phase branch pipe S01B. The third cut-off valve XV2 for the ship-unloading liquid-phase branch pipe is used to control the on-off of the third ship-unloading liquid-phase branch pipe S01B.

[0043] A fourth nitrogen purge pipeline XV13 is provided at the connection between the ship-unloading gas pipeline S02 and the ship-unloading gas-phase arm L02. A fourth temperature sensor T4 and a fourth pressure sensor P3 are respectively arranged on the ship-unloading gas pipeline S02. An LPG ship-unloading gas-phase cut-off valve XV7 is arranged on the LPG ship-unloading gas-phase branch pipe S22. A ship-unloading return gas pressure regulating valve PCV1 is also arranged on the ship-unloading gas pipeline S02. Both ends of the ship-unloading return gas pressure regulating valve PCV1 are connected with a fifth pressure sensor P5. The fourth nitrogen purge pipeline XV13 is used to purge the remaining LPG at the connection between the ship-unloading gas pipeline S02 and the ship-unloading gas-phase arm L02. The fourth temperature sensor T4 and the fourth pressure sensor P3 are respectively used to detect the temperature and pressure in the fourth ship-unloading liquid-phase branch pipe. The LPG ship-unloading gas-phase cut-off valve XV7 is used to control the on-off of the LPG ship-unloading gas-phase branch pipe S22. The ship-unloading return gas pressure regulating valve PCV1 is used to control the on-off of the ship-unloading gas pipeline S02.

[0044] An LNG ship unloading liquid pipeline S11 is connected with an LNG ship unloading main pipeline drainage pipeline S15. The other end of the LNG ship unloading main pipeline drainage pipeline S15 is connected with a ship unloading liquid main pipeline S03. An LNG ship unloading drainage valve MV1 is arranged on the LNG ship unloading main pipeline drainage pipeline S15. The LNG ship unloading main pipeline drainage pipeline S15 is used to drain the residual LNG in the LNG ship unloading liquid pipeline S11 into the ship unloading liquid main pipeline S03, and the LNG ship unloading drainage valve MV1 is used to control the on-off of the LNG ship unloading main pipeline drainage pipeline S15.

[0045] An LPG ship unloading liquid pipeline S21 is connected with an LPG ship unloading main pipeline drainage pipeline S25. The other end of the LPG ship unloading main pipeline drainage pipeline S25 is connected with a ship unloading liquid main pipeline S03. An LPG ship unloading drainage valve MV2 is arranged on the LPG ship unloading main pipeline drainage pipeline S25. The LPG ship unloading main pipeline drainage pipeline S25 is used to drain the residual LPG in the LPG ship unloading liquid pipeline S21 into the ship unloading liquid main pipeline S03, and the LPG ship unloading drainage valve MV2 is used to control the on-off of the LPG ship unloading main pipeline drainage pipeline S25.

[0046] In an embodiment of the present invention, the LNG ship unloading liquid pipeline S11 is connected with the LNG ship unloading cold circulation pipeline S13. The two connection points of this passage are respectively located after the LNG ship unloading liquid cut-off valve XV4 on the LNG ship unloading liquid pipeline S11 and before the LNG cold circulation cut-off valve XV8 on the LNG ship unloading cold circulation pipeline S13.

[0047] In an embodiment of the present invention, the LPG ship unloading liquid pipeline S21 is connected with the LPG ship unloading cold circulation pipeline S23. The two connection points of this passage are respectively located after the LPG ship unloading liquid cut-off valve XV5 on the LPG ship unloading liquid pipeline S21 and between the LPG ship unloading cold circulation manual valve and the LPG cold circulation cut-off valve on the LPG ship unloading cold circulation pipeline S23.

[0048] The working principle of the ship unloading system of the shared ship unloading arm for LNG and LPG in the embodiment of the present invention is specifically as follows:

[0049] Before the arrival of the LNG ship or LPG ship, the embodiment of the present invention performs cold circulation operation by using LNG or LPG through the ship unloading liquid main pipeline S03. At this time, the first cut-off valve XV1 of the ship unloading liquid branch pipe, the second cut-off valve XV3 of the ship unloading liquid branch pipe, the third cut-off valve XV2 of the ship unloading liquid branch pipe, the ship unloading return gas pressure regulating valve PCV1, the LNG ship unloading gas cut-off valve XV6, the LPG ship unloading gas cut-off valve XV7, the first nitrogen purging pipeline XV10, the third nitrogen purging pipeline XV11, the second nitrogen purging pipeline XV12 and the fourth nitrogen purging pipeline XV13 are all in the closed state.

[0050] When performing cold cycle operation with LNG, the LNG cold cycle cut-off valve XV8, the LNG ship unloading cold cycle manual valve MV3, and the LNG ship unloading liquid phase cut-off valve XV4 are in the open state, the LNG ship unloading drain valve MV1 is closed, and the LNG flow direction is LNG storage system → LNG ship unloading cold cycle pipeline S13 → LNG to common ship unloading main pipe cold insulation cycle pipeline S14 → ship unloading liquid phase main pipe S03 → LNG ship unloading liquid phase pipeline S11 → LNG storage system; the LPG cold cycle cut-off valve XV9 is open, the LPG ship unloading cold cycle manual valve MV4, the LPG ship unloading liquid phase cut-off valve XV5, and the LPG ship unloading drain valve MV2 are all closed, and the LPG flow direction is LPG storage system → LPG ship unloading cold cycle pipeline S23 → LPG ship unloading liquid phase pipeline S21 → LPG storage system.

[0051] When performing cold cycle operation with LPG, the LPG cold cycle cut-off valve XV9, the LPG ship unloading cold cycle manual valve MV4, and the LPG ship unloading liquid phase cut-off valve XV5 are in the open state, the LPG ship unloading drain valve MV2 is closed, and the LPG flow direction is LPG storage system → LPG ship unloading cold cycle pipeline S23 → LPG to common ship unloading main pipe cold insulation cycle pipeline S24 → ship unloading liquid phase main pipe S03 → LPG ship unloading liquid phase pipeline S21 → LPG storage system; the LNG cold cycle cut-off valve XV8 is open, the LNG ship unloading liquid phase cut-off valve XV4, the LNG ship unloading drain valve MV1, and the LNG ship unloading cold cycle manual valve MV3 are closed, and the LNG flow direction is LNG storage system → LNG ship unloading cold cycle pipeline S13 → LNG ship unloading liquid phase pipeline S11 → LNG storage system.

[0052] When the LNG ship docks, in the embodiment of the present invention, the cold cycle is first shut down. The first ship unloading liquid phase arm L01A, the ship unloading gas / liquid phase arm L01B, the second ship unloading liquid phase arm L01C, and the ship unloading gas phase arm L02 are respectively connected to the LNG ship. The first cut-off valve XV1 of the ship unloading liquid phase branch pipe, the second cut-off valve XV3 of the ship unloading liquid phase branch pipe, the third cut-off valve XV2 of the ship unloading liquid phase branch pipe, the LNG ship unloading liquid phase cut-off valve XV4, and the LNG ship unloading gas phase cut-off valve XV6 are opened. The ship unloading return gas pressure regulating valve PCV1 is put into automatic control, and the rest of the valves are in the closed state. The LNG completes the ship unloading along the process of the first ship unloading liquid phase arm L01A / ship unloading gas / liquid phase arm L01B / second ship unloading liquid phase arm L01C → ship unloading liquid main pipe S03 → LNG ship unloading liquid pipeline S11 → LNG storage system. The BOG (BOG is flash gas, that is, the gas after LNG evaporates and gasifies) of the LNG storage system returns to the LNG ship through the LNG ship unloading gas phase branch pipe S12 → ship unloading gas pipeline S02 → ship unloading gas phase arm L02. After the ship unloading is completed, the first nitrogen purge pipeline XV10, the third nitrogen purge pipeline XV11, and the second nitrogen purge pipeline XV12 are opened, and the remaining LNG in the first ship unloading liquid phase branch pipe S01A, the third ship unloading liquid phase branch pipe S01B, and the second ship unloading liquid phase branch pipe S01C is purged into the ship unloading liquid main pipe S03, and the LNG ship is disconnected from the first ship unloading liquid phase arm L01A, the ship unloading gas / liquid phase arm L01B, the second ship unloading liquid phase arm L01C, and the ship unloading gas phase arm L02.

[0053] When the LPG ship docks, in the embodiment of the present invention, the cold cycle is first closed. The first ship unloading liquid phase arm L01A, the ship unloading gas / liquid phase arm L01B, the second ship unloading liquid phase arm L01C, and the ship unloading gas phase arm L02 are respectively connected to the LPG ship. The first cut-off valve XV1 of the ship unloading liquid phase branch pipe, the second cut-off valve XV3 of the ship unloading liquid phase branch pipe, the third cut-off valve XV2 of the ship unloading liquid phase branch pipe, the LPG ship unloading liquid cut-off valve XV5, and the LPG ship unloading gas cut-off valve XV7 are opened. The ship unloading return gas pressure regulating valve PCV1 is put into automatic control, and the rest of the valves are in the closed state. LPG is unloaded along the first ship unloading liquid phase branch pipe S01A / the third ship unloading liquid phase branch pipe S01B / the second ship unloading liquid phase branch pipe S01C → the ship unloading liquid main pipe S03 → the LPG ship unloading liquid pipeline S21 → the LPG storage system process. The BOG of the LPG storage system returns to the LPG ship through the LPG ship unloading gas phase branch pipe S22 → the ship unloading gas pipeline S02 → the ship unloading gas phase arm L02. After the ship unloading is completed, the first nitrogen purge pipeline XV10, the third nitrogen purge pipeline XV11, and the second nitrogen purge pipeline XV12 are opened, and the remaining LPG in the first ship unloading liquid phase branch pipe S01A, the third ship unloading liquid phase branch pipe S01B, and the second ship unloading liquid phase branch pipe S01C is purged into the ship unloading liquid main pipe S03. The LPG ship is disconnected from the first ship unloading liquid phase arm L01A, the ship unloading gas / liquid phase arm L01B, the second ship unloading liquid phase arm L01C, and the ship unloading gas phase arm L02.

[0054] The ship unloading system of the common ship unloading arm for LNG and LPG in the embodiment of the present invention has the following advantages compared with the prior art:

[0055] 1. When facing an LNG ship or an LPG ship, by switching the corresponding pipelines in the supporting main pipe assembly respectively, a set of common ship unloading arm assembly is realized, and the independently unloaded LNG or LPG is transported to the corresponding LNG storage system or LPG storage system for storage, which reduces the cost, simplifies the operation process, and improves the stability of the plant operation;

[0056] 2. Cut-off valves are respectively arranged on the ship unloading pipelines corresponding to LNG and LPG to realize the independent ship unloading operation of LNG and LPG, avoiding the risk of LNG and LPG mixing;

[0057] 3. Corresponding ship unloading cold cycle pipelines are respectively arranged in the LNG ship unloading and LPG ship unloading processes. By adjusting the valve states of different pipelines, it is possible to keep the LNG ship unloading main pipe and the LPG ship unloading main pipe in a cold state respectively by using the existing LNG or LPG under non-ship unloading conditions;

[0058] 4. Corresponding drainage pipelines and purge pipelines are respectively arranged on the ship unloading pipelines of LNG and LPG, which is convenient for draining and purging the LNG and LPG pipelines after the ship unloading operation is completed.

[0059] In the specification provided herein, numerous specific details are set forth. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail so as not to obscure an understanding of the present specification.

[0060] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the foregoing description of exemplary embodiments of the invention, the various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof. However, the disclosed method should not be construed as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, the inventive aspects lie in less than all of the features of the single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of the invention.

[0061] It should be noted that the above embodiments are illustrative of the invention and not restrictive thereof, and that alternative embodiments may be devised by those skilled in the art without departing from the scope of the appended claims.

Claims

1. A ship unloading system with a shared ship unloading arm for LNG and LPG, characterized in that, the ship unloading system with a shared ship unloading arm for LNG and LPG includes: A ship unloading arm assembly, including a ship unloading liquid phase arm assembly and a ship unloading gas phase arm. The ship unloading liquid phase arm assembly includes a parallel - arranged ship unloading gas / liquid phase arm, a first ship unloading liquid phase arm, and a second ship unloading liquid phase arm; A supporting main pipe assembly, including a ship unloading liquid phase branch pipe assembly, a ship unloading liquid phase main pipe, a ship unloading gas phase pipeline, an LNG ship unloading liquid phase pipeline, an LPG ship unloading liquid phase pipeline, an LNG ship unloading gas phase branch pipe, and an LPG ship unloading gas phase branch pipe. The ship unloading liquid phase branch pipe assembly includes a first ship unloading liquid phase branch pipe, a second ship unloading liquid phase branch pipe, and a third ship unloading liquid phase branch pipe. Among them, an LNG ship unloading liquid phase cut - off valve is arranged on the LNG ship unloading liquid phase pipeline, an LPG ship unloading liquid phase cut - off valve is arranged on the LPG ship unloading liquid phase pipeline, an LNG ship unloading gas phase cut - off valve is arranged on the LNG ship unloading gas phase branch pipe, and an LPG ship unloading gas phase cut - off valve is arranged on the LPG ship unloading gas phase branch pipe; An LNG storage system for storing LNG; An LPG storage system for storing LPG; Among them, the first ship unloading liquid phase arm is connected to the ship unloading liquid phase main pipe through the first ship unloading liquid phase branch pipe; the second ship unloading liquid phase arm is connected to the ship unloading liquid phase main pipe through the second ship unloading liquid phase branch pipe; the ship unloading gas / liquid phase arm is respectively connected to the ship unloading liquid phase main pipe and the ship unloading gas phase pipeline through the third ship unloading liquid phase branch pipe; the ship unloading gas phase arm is connected to the LPG ship unloading gas phase branch pipe through the ship unloading gas phase pipeline, and the LPG ship unloading gas phase branch pipe is connected to the LPG storage system; the ship unloading liquid phase main pipe is connected to the LNG storage system through the LNG ship unloading liquid phase pipeline, and the ship unloading liquid phase main pipe is connected to the LPG storage system through the LPG ship unloading liquid phase pipeline; an LNG ship unloading gas phase branch pipe is connected between the LNG storage system and the ship unloading gas phase pipeline.

2. The ship unloading system with a shared ship unloading arm for LNG and LPG according to claim 1, characterized in that, an LNG ship unloading cold circulation pipeline is connected to the LNG storage system. The LNG ship unloading cold circulation pipeline is connected to the ship unloading liquid phase main pipe through an LNG to shared ship unloading main pipe cold insulation circulation pipeline. An LNG cold circulation cut - off valve and an LNG ship unloading cold circulation manual valve are arranged on the LNG ship unloading cold circulation pipeline.

3. The ship unloading system with a shared ship unloading arm for LNG and LPG according to claim 1, characterized in that, an LPG ship unloading cold circulation pipeline is connected to the LPG storage system. The LPG ship unloading cold circulation pipeline is connected to the ship unloading liquid phase main pipe through an LPG to shared ship unloading main pipe cold insulation circulation pipeline. An LPG cold circulation cut - off valve and an LPG ship unloading cold circulation manual valve are arranged on the LPG ship unloading cold circulation pipeline.

4. The ship unloading system with a shared ship unloading arm for LNG and LPG according to claim 1, characterized in that, A first nitrogen purging pipeline is provided at the connection between the first ship-unloading liquid-phase branch pipe and the first ship-unloading liquid-phase arm, and a first temperature sensor, a first pressure sensor and a first cut-off valve for the ship-unloading liquid-phase branch pipe are respectively provided on the first ship-unloading liquid-phase branch pipe.

5. The ship-unloading system for sharing a ship-unloading arm by LNG and LPG according to claim 1, characterized in that a second nitrogen purging pipeline is provided at the connection between the second ship-unloading liquid-phase branch pipe and the second ship-unloading liquid-phase arm, and a second temperature sensor, a second pressure sensor and a second cut-off valve for the ship-unloading liquid-phase branch pipe are respectively provided on the second ship-unloading liquid-phase branch pipe.

6. The ship-unloading system for sharing a ship-unloading arm by LNG and LPG according to claim 1, characterized in that a third nitrogen purging pipeline is provided at the connection between the third ship-unloading liquid-phase branch pipe and the ship-unloading gas / liquid-phase arm, and a third temperature sensor, a third pressure sensor and a third cut-off valve for the ship-unloading liquid-phase branch pipe are respectively provided on the third ship-unloading liquid-phase branch pipe.

7. The ship-unloading system for sharing a ship-unloading arm by LNG and LPG according to claim 1, characterized in that a fourth nitrogen purging pipeline is provided at the connection between the ship-unloading gas pipeline and the ship-unloading gas arm, a fourth temperature sensor and a fourth pressure sensor are respectively provided on the ship-unloading gas pipeline, and an LPG ship-unloading gas cut-off valve is provided on the LPG ship-unloading gas branch pipe.

8. The ship-unloading system for sharing a ship-unloading arm by LNG and LPG according to claim 7, characterized in that a ship-unloading return gas pressure regulating valve is further provided on the ship-unloading gas pipeline, and fifth pressure sensors are connected to both ends of the ship-unloading return gas pressure regulating valve.

9. The ship-unloading system for sharing a ship-unloading arm by LNG and LPG according to claim 1, characterized in that an LNG ship-unloading main pipe drainage pipeline is communicated and provided on the LNG ship-unloading liquid pipeline, the other end of the LNG ship-unloading main pipe drainage pipeline is communicated with the ship-unloading liquid main pipe, and an LNG ship-unloading drainage valve is provided on the LNG ship-unloading main pipe drainage pipeline.

10. The ship-unloading system for sharing a ship-unloading arm by LNG and LPG according to claim 1, characterized in that a LPG ship-unloading main pipe drainage pipeline is communicated and provided on the LPG ship-unloading liquid pipeline, the other end of the LPG ship-unloading main pipe drainage pipeline is communicated with the ship-unloading liquid main pipe, and an LPG ship-unloading drainage valve is provided on the LPG ship-unloading main pipe drainage pipeline.

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