A method and system for simultaneous bunkering of natural gas and liquid nitrogen to a single ship at a terminal

Abstract

The application discloses a method and system for synchronously filling natural gas and liquid nitrogen for a single ship in a wharf, which carries out two low-temperature operations in the same time period, uses a ship's sweeping pipe as a main pipeline for liquid nitrogen blowing in a first stage, inertizes the pipeline in the process of liquid nitrogen blowing, and thus has conditions for directly filling natural gas. In a second stage, when natural gas is filled into a cargo hold, only relevant metal hoses need to be removed, so that synchronous operation of filling natural gas and liquid nitrogen on the ship can be realized. The application ensures that LNG is filled into the cargo hold on the ship at the most appropriate time, thereby reducing volatilization of the LNG and saving a large amount of cost. Meanwhile, the application does not stop liquid nitrogen operation on the ship while filling LNG into the cargo hold on the ship, ensures the continuity of debugging of cryogenic equipment, and saves the debugging time.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of shipbuilding, in particular to a method and system for simultaneous natural gas and liquid nitrogen filling of a single ship at a wharf. BACKGROUND

[0002] LNG ships are known as the "crown jewel" of the shipbuilding industry, and the ultra-low temperature cargo operating system has always been the main construction focus and difficulty. The Cryostar cryogenic device requires a large amount of pure nitrogen gas to be used for internal pipeline dew point purging, and during the cryogenic debugging, LNG in the cargo hold is needed for function test. LNG will volatilize in the cargo hold every day, so in order to save costs, LNG filling will be carried out when the dew point purging of the cryogenic device is about to be completed, so as to reduce the storage time of natural gas in the cabin as much as possible, thereby reducing the volatilization amount of LNG.

[0003] The temperature of LNG is-163 DEG C, and the temperature of liquid nitrogen is-196 DEG C. Due to the particularity of the Cryostar cryogenic device, both low-temperature operations need to be carried out during the debugging process of the cryogenic equipment. SUMMARY

[0004] To solve the above technical problems, the present application provides a method and system for simultaneous natural gas and liquid nitrogen filling of a single ship at a wharf, which reduces the volatilization of LNG in the cargo hold and saves the debugging time of the cryogenic equipment.

[0005] The purpose of the present application is achieved by the following technical scheme, a method for simultaneous natural gas and liquid nitrogen filling of a single ship at a wharf, comprising the following steps:

[0006] S1: connecting two temporary pipelines on the first liquid phase pipe at the head and tail of the gas collection platform on the ship, one of the two temporary pipelines is an LNG temporary filling pipe, and the other is a liquid nitrogen temporary filling pipe;

[0007] S2: connecting the other end of the liquid nitrogen temporary filling pipe with the outlet of the first gasifier, and connecting the inlet of the first gasifier with a liquid nitrogen storage source; connecting the other side of the LNG temporary filling pipe with the outlet of the second gasifier, and connecting the inlet of the second gasifier with an LNG gas source;

[0008] S3: connecting the outlet of the sampling pipe on the tail liquid phase pipe with the sampling pipe on the head liquid phase pipe through a metal hose;

[0009] S4: the liquid nitrogen in the liquid nitrogen storage source is gasified into normal temperature nitrogen gas through the first gasifier, enters the liquid phase pipe through the liquid nitrogen temporary filling pipe, and then enters the metal hose through the sampling pipe, so as to gasify the LNG filling path pipeline;

[0010] S5: connecting the sampling pipe on the LNG filling path pipeline near the cryogenic equipment with the cryogenic equipment through a metal hose, and performing cryogenic equipment refrigerant pipeline purging;

[0011] S6: when LNG needs to be filled on the ship, filling is performed using the LNG filling path pipeline, the sampling pipe valve on the LNG filling path pipeline near the cryogenic equipment is closed, the terminal LNG gas source is connected with the LNG temporary filling pipe and the second gasifier, and LNG filling operation is performed;

[0012] S7: the metal hose on the sampling pipe on the LNG filling path pipeline near the cryogenic equipment is removed, meanwhile, a plurality of metal hoses are used to connect the sampling pipe on the cryogenic equipment nearby the cabin cleaning pipe to the cryogenic equipment refrigerant pipeline inlet position, the cryogenic equipment refrigerant pipeline inlet is temporarily not connected, until the dew point in the metal hose is lower than the preset value, the cryogenic equipment refrigerant pipeline inlet is connected, and the terminal liquid nitrogen is used to purge the cryogenic equipment refrigerant pipeline.

[0013] Preferably, in S1, the head liquid phase pipe is connected with the LNG temporary filling pipe, and the tail liquid phase pipe is connected with the liquid nitrogen temporary filling pipe.

[0014] Preferably, in S2, the liquid nitrogen storage source at least includes a liquid nitrogen storage tank or a liquid nitrogen tank truck; and the LNG gas source at least includes an LNG tank truck.

[0015] Preferably, in S3, the fourth tail liquid phase pipe sampling pipe outlet is connected with the metal hose inlet, and the metal hose outlet is connected with the first head liquid phase pipe sampling pipe.

[0016] Preferably, in S4, the LNG filling path pipeline nitrogen gasification process ends until the dew point of the LNG filling path pipeline is lower than-50 DEG C.

[0017] Preferably, in S5, the metal hose connected sampling pipe on the LNG filling path pipeline near the cryogenic equipment is the nearest sampling pipe, and the metal hose connected cryogenic equipment interface is the refrigerant pipeline inlet valve.

[0018] Preferably, in S7, the preset value of the dew point in the metal hose is-50 DEG C.

[0019] The present application provides a method for synchronously filling natural gas and liquid nitrogen for a single ship at a terminal, and further provides a system for realizing the method.

[0020] The system comprises:

[0021] The first gasifier and the second gasifier are connected with the liquid nitrogen storage source and the LNG gas source respectively, and the outlets thereof are connected with the inlets of the liquid nitrogen temporary filling pipe and the LNG temporary filling pipe respectively.

[0022] The outlets of the temporary liquid nitrogen filling pipe and the temporary LNG filling pipe are respectively connected to the first liquid phase pipe at the head and tail of the gas gathering platform on the ship.

[0023] As needed, multiple metal hoses are used to connect the sampling tube outlet on the tail liquid phase pipe and the head liquid phase pipe, the sampling tube on the LNG filling path pipeline near the cryogenic equipment and the refrigerant pipeline inlet of the cryogenic equipment, and the sampling tube on the tank sweeping pipe near the cryogenic equipment is connected to the refrigerant pipeline inlet of the cryogenic equipment through the metal hose.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The present invention provides a method and system for the simultaneous filling of natural gas and liquid nitrogen on a single ship at a dock. By performing two low-temperature operations in the same time period, in the first stage, a ship-type cabin sweeping pipe is used as the main line for liquid nitrogen purging. During the liquid nitrogen purging process, the pipeline has been inerted, thereby meeting the conditions for direct filling of natural gas. When filling the cargo hold with natural gas in the second stage, it is only necessary to remove the metal hose at the relevant position to achieve the simultaneous operation of filling natural gas and liquid nitrogen on board. The present invention ensures that LNG is added to the cargo hold on board at the most appropriate time, thereby reducing the volatilization of LNG and saving a lot of costs. At the same time, this invention does not stop the liquid nitrogen operation on board while filling the cargo hold on board with LNG, thereby ensuring the connectivity of the cryogenic equipment commissioning and saving commissioning time. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Fig. 1 This is a flow chart of a method for simultaneously filling a single ship with natural gas and liquid nitrogen at a dock according to the present invention;

[0027] Fig. 2 Schematic diagram of the arrangement of a system for synchronously filling natural gas and liquid nitrogen for a single ship at a dock according to an embodiment of the present invention;

[0028] Fig. 3 This is a schematic diagram of the layout of interfaces and pipelines on board an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0030] The technical scheme of the present application provides a method for synchronously filling natural gas and liquid nitrogen for a single ship at a wharf, which is used for installation and commissioning of a cryogenic device (or similar device) at a wharf. Before the cryogenic device is commissioned in an LNG state, the cryogenic device needs to be operated to reduce a dew point of a refrigerant pipeline and to fill the refrigerant. Pure nitrogen gas after gasification of liquid nitrogen is used to supplement nitrogen gas and reduce the dew point of the refrigerant main pipeline. In order to ensure continuity of commissioning, the LNG filling work of a cargo warehouse is carried out during a series of operations of the refrigerant pipeline of the cryogenic device. When two parallel working conditions occur, a special operation method is adopted, as shown in the figure. The method comprises the following steps: Figs. 1 to 3

[0031] S1: two temporary pipelines are connected to the first liquid-phase pipeline at the head and tail of a gas collection platform on the ship, one of the two temporary pipelines is an LNG temporary filling pipeline, and the other is a liquid nitrogen temporary filling pipeline, the two pipelines extend to the shore, wherein the head liquid-phase pipeline is connected to the LNG temporary filling pipeline, and the tail liquid-phase pipeline is connected to the liquid nitrogen temporary filling pipeline;

[0032] S2: the other end of the liquid nitrogen temporary filling pipeline is connected to the outlet of a first gasifier, and the inlet of the first gasifier is connected to a liquid nitrogen storage source; the other side of the LNG temporary filling pipeline is connected to the outlet of a second gasifier, and the inlet of the second gasifier is connected to an LNG gas source, the liquid nitrogen storage source can be a liquid nitrogen storage tank or a liquid nitrogen tank truck, and the LNG gas source is an LNG tank truck.

[0033] S3: the outlet of a sampling pipe on the tail liquid-phase pipeline is connected to the sampling pipe on the head liquid-phase pipeline through a metal hose, specifically, the outlet CPV04 of the sampling pipe on the fourth tail liquid-phase pipeline is connected to the inlet of the metal hose, and the outlet of the metal hose is connected to the sampling pipe CPV01 on the first head liquid-phase pipeline;

[0034] S4: liquid nitrogen in the liquid nitrogen storage source is gasified into normal-temperature nitrogen gas through the first gasifier, enters the liquid-phase pipeline through the liquid nitrogen temporary filling pipeline, and then enters the metal hose through the sampling pipe, so that the nitrogen gas is filled into the LNG filling path pipeline (cabin cleaning pipeline), and the dew point of the LNG filling path pipeline (cabin cleaning pipeline) is lower than -50℃;

[0035] S5: the sampling pipe on the LNG filling path pipeline near the cryogenic device is connected to an interface of the cryogenic device through the metal hose, and the refrigerant pipeline of the cryogenic device is purged, specifically, the sampling pipe CSV01 on the LNG filling path pipeline near the cryogenic device connected by the metal hose is the nearest sampling pipe, and the interface of the cryogenic device connected by the metal hose is the inlet valve MV02 of the refrigerant pipeline.

[0036] ​S6: When the ship needs to be filled with LNG, the LNG filling path pipeline is used for filling. Since the refrigerant pipeline nitrogen purging is performed using the scavenging pipeline in advance, the scavenging pipeline has LNG filling conditions (dew point < -40℃, oxygen content < 4%), the sampling pipe valve CSV01 valve on the LNG filling path pipeline near the cryogenic equipment is closed, the terminal LNG gas source is connected with the LNG temporary filling pipe and the second vaporizer, and the LNG filling operation is performed;

[0037] S7: The metal hose on the sampling pipe of CSV01 and CPV01 on the LNG filling path pipeline near the cryogenic equipment is removed, and a plurality of metal hoses are used to connect the sampling pipe CPV01 on the scavenging pipeline near the cryogenic equipment to the inlet MV02 of the refrigerant pipeline of the cryogenic equipment in a head-to-tail manner. The inlet MV02 of the refrigerant pipeline of the cryogenic equipment is temporarily not connected until the dew point in the metal hose is lower than -50℃, and is connected with the inlet MV02 of the refrigerant pipeline of the cryogenic equipment. The cryogenic equipment refrigerant pipeline is purged using the terminal liquid nitrogen.

[0038] The method provided in the embodiment is an important part of the first set of ship cryogenic equipment debugging work in the world. The core is to perform two low-temperature operations in the same time period. In the first stage, the ship scavenging pipeline is used as the main pipeline for liquid nitrogen purging. During the liquid nitrogen purging process, the pipeline has been inerted, thereby having the condition for directly filling natural gas. In the second stage, when filling natural gas into the cargo hold, only the metal hose at the relevant position needs to be removed, so that the simultaneous operation of filling natural gas and liquid nitrogen on the ship can be realized.

[0039] In the embodiment, the pure nitrogen gas vaporized on the ship is introduced into the scavenging pipeline through the liquid phase pipeline at the bow, and is connected with the metal hose at the CSV01 position, so as to be sent into the cryogenic room for use in purging the refrigerant pipeline of the cryogenic equipment.

[0040] After the dew point of the refrigerant pipeline of the cryogenic equipment reaches the standard, the metal hose between CPV01 and CPV04 is removed, the LNG tank truck on the terminal is connected with the 2# vaporizer, the 2# vaporizer is connected with the LNG filling temporary pipe, and the LNG is filled into the ship.

[0041] One end of the metal hose is connected with CPV04, a plurality of metal hoses are connected in a head-to-tail manner, and the hose is connected to the inside of the cryogenic room, so as to continue to provide the terminal pure nitrogen gas for the cryogenic equipment.

[0042] In the present application, the nitrogen gas after liquefied nitrogen gasification is connected to the LNG filling pipeline through a metal hose, so as to use the warehouse scanning pipeline on the ship as the main pipeline for nitrogen gas blowing, and in the nitrogen gas blowing process, the warehouse scanning pipeline is inerted, so as to make the warehouse scanning pipeline have the condition of directly filling LNG. When the ship needs to fill LNG, only the S7 step is operated, and the LNG can be directly filled to the ship. The metal hose is connected to the CPV04 at one end, a plurality of metal hoses are connected at the end, the hose is connected to the inside of the cryogenic room, and the pure nitrogen gas of the terminal is provided to the cryogenic equipment.

[0043] In addition to providing a method for synchronously filling natural gas and liquid nitrogen for a single ship at a terminal, the present application further provides a system for realizing the above method, which comprises:

[0044] A first gasifier, a second gasifier, a liquid nitrogen temporary filling pipe, an LNG temporary filling pipe and a plurality of metal hoses.

[0045] The inlet of the first gasifier and the second gasifier is connected to the liquid nitrogen storage source and the LNG gas source respectively, and the outlet is connected to the inlet of the liquid nitrogen temporary filling pipe and the LNG temporary filling pipe respectively.

[0046] The outlet of the liquid nitrogen temporary filling pipe and the LNG temporary filling pipe is connected to the first liquid phase pipe at the head and tail of the ship gas collection platform respectively.

[0047] The plurality of metal hoses are connected to the sampling pipe outlet of the tail liquid phase pipe, the sampling pipe of the head liquid phase pipe, the sampling pipe of the LNG filling path pipeline near the cryogenic equipment and the inlet of the cryogenic equipment refrigerant pipeline according to the needs.

[0048] The above is the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be considered as the protection scope of the present application.

Claims

1. A method for simultaneously filling a single ship with natural gas and liquid nitrogen at a dock, characterized by: The method comprises the following steps: S1: Connect two temporary pipelines to the bow liquid phase pipe and the stern liquid phase pipe of the gas gathering platform on board. One of the two temporary pipelines is a temporary LNG filling pipe and the other is a temporary liquid nitrogen filling pipe. The bow liquid phase pipe is connected to the temporary LNG filling pipe, and the stern liquid phase pipe is connected to the temporary liquid nitrogen filling pipe. S2: Connect the other end of the temporary liquid nitrogen filling pipe to the outlet of the first vaporizer, and connect the inlet of the first vaporizer to the liquid nitrogen storage source; connect the other end of the temporary LNG filling pipe to the outlet of the second vaporizer, and connect the inlet of the second vaporizer to the LNG gas source; S3: Connect the outlet of the sampling tube on the tail liquid phase tube to the sampling tube on the head liquid phase tube through a metal hose; S4: The liquid nitrogen in the liquid nitrogen storage source is vaporized into room temperature nitrogen through the first vaporizer, enters the tail liquid phase pipe through the liquid nitrogen temporary filling pipe, and then enters the metal hose through the sampling pipe to nitrogenize the LNG filling path pipeline; S5: Connect the sampling tube on the LNG filling path pipeline near the cryogenic equipment to the interface of the cryogenic equipment through a metal hose to purge the refrigerant pipeline of the cryogenic equipment; S6: When LNG needs to be refueled on board, use the LNG refueling route pipeline to refuel, close the sampling pipe valve on the LNG refueling route pipeline near the cryogenic equipment, connect the LNG gas source at the dock to the LNG temporary refueling pipe and the second vaporizer, and carry out LNG refueling operations; S7: Remove the metal hose on the sampling tube on the LNG filling route pipeline near the cryogenic equipment, and use multiple metal hoses at the same time to connect the sampling tube on the sweeping pipe near the cryogenic equipment to the refrigerant pipeline inlet of the cryogenic equipment end to end. The refrigerant pipeline inlet of the cryogenic equipment is temporarily disconnected until the dew point in the metal hose is lower than the preset value, and then connect it to the refrigerant pipeline inlet of the cryogenic equipment, and use liquid nitrogen at the dock to purge the refrigerant pipeline of the cryogenic equipment.

2. The method for simultaneously filling a single ship with natural gas and liquid nitrogen at a dock according to claim 1, characterized in that: In S2, the liquid nitrogen storage source includes at least a liquid nitrogen storage tank or a liquid nitrogen tank truck; the LNG gas source includes at least an LNG tank truck.

3. The method for synchronously filling a single ship with natural gas and liquid nitrogen at a dock according to claim 2, characterized in that: In the above S3, the outlet of the sampling tube on the tail liquid phase tube is connected to the inlet of the metal hose, and the outlet of the metal hose is connected to the sampling tube on the head liquid phase tube.

4. The method for simultaneously filling a single ship with natural gas and liquid nitrogen at a dock according to claim 3, characterized in that: In the above-mentioned S4, the nitrogen gasification process of the LNG filling pipeline is terminated when the dew point of the LNG filling pipeline is lower than -50°C.

5. The method for simultaneously filling a single ship with natural gas and liquid nitrogen at a dock according to claim 4, characterized in that: In the above S5, the sampling tube on the LNG filling path pipeline near the cryogenic equipment connected by the metal hose is the sampling tube closest to it, and the interface of the cryogenic equipment connected by the metal hose is the inlet valve of the refrigerant pipeline.

6. The method for simultaneously filling a single ship with natural gas and liquid nitrogen at a dock according to claim 5, characterized in that: In the above-mentioned S7, the dew point in the metal hose is preset to -50°C.

7. A system for simultaneously refueling a single ship with natural gas and liquid nitrogen at a dock, characterized by: The system is used to implement the method for synchronously filling a single ship with natural gas and liquid nitrogen at a terminal according to any one of claims 1 to 6, and the system comprises: A first vaporizer, a second vaporizer, a temporary liquid nitrogen filling pipe, a temporary LNG filling pipe, and multiple metal hoses; The inlets of the first vaporizer and the second vaporizer are connected to the liquid nitrogen storage source and the LNG gas source respectively, and the outlets are connected to the inlets of the liquid nitrogen temporary filling pipe and the LNG temporary filling pipe respectively; The outlets of the temporary liquid nitrogen filling pipe and the temporary LNG filling pipe are connected to the head liquid phase pipe and the tail liquid phase pipe of the gas gathering platform on board respectively; As needed, multiple metal hoses are used to connect the sampling tube outlet on the tail liquid phase pipe and the head liquid phase pipe, the sampling tube on the LNG filling path pipeline near the cryogenic equipment and the refrigerant pipeline inlet of the cryogenic equipment, and the sampling tube on the tank sweeping pipe near the cryogenic equipment is connected to the refrigerant pipeline inlet of the cryogenic equipment through the metal hose.

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