An LNG loading and unloading integrated skid

Abstract

The present invention relates to an integrated LNG loading and unloading skid, which comprises a set of LNG loading and unloading arms and a loading and unloading skid body. An auxiliary pipeline is installed on the loading and unloading skid body. The auxiliary pipeline includes a vent pipeline, a drainage pipeline, and a nitrogen purging and protection pipeline. A loading and unloading pipeline system for realizing integrated loading and unloading is installed on the loading and unloading skid body. The loading and unloading pipeline system includes a vapor pipeline, a liquid-phase loading pipeline, a liquid-phase unloading pipeline, and a vaporization and pressurization pipeline. The present invention realizes the functions of loading or unloading according to needs with a single skid-mounted device through the combination of the liquid-phase loading pipeline and the liquid-phase unloading pipeline. At the same time, the setting of the direct unloading pipeline and the pump unloading pipeline realizes the dual-purpose process of cryogenic pump unloading and vaporizer pressurization unloading, saves production costs, and has good social benefits.

Description

Technical Field

[0001] The present invention relates to a fluid loading and unloading device, in particular to an integrated LNG loading and unloading skid. Background Art

[0002] At present, the land transportation of LNG mainly relies on road tankers. With the wide application of LNG, a clean, efficient and green energy source, the demand for LNG storage and transportation is constantly increasing, and the technological requirements for loading and unloading equipment are also constantly innovating. During the traditional LNG transfer and loading / unloading, a single loading / unloading bay can only achieve a single loading or unloading function. If it does not match, it can only be replaced to a loading / unloading bay that matches the loading / unloading requirement function for loading or unloading, which greatly wastes the spatial position of the transfer area and increases the demand for loading and unloading equipment, wasting equipment costs. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an integrated LNG loading and unloading skid that can achieve integrated loading and unloading, and at the same time, the unloading realizes the dual processes of vaporizer pressurized unloading and cryogenic pump unloading in view of the deficiencies of the prior art.

[0004] The technical problem to be solved by the present invention is realized through the following technical solutions. The present invention is an integrated LNG loading and unloading skid, including a set of LNG loading and unloading arms and a loading and unloading skid body. The LNG loading and unloading arms include a vapor phase loading and unloading arm and a liquid phase loading and unloading arm. Auxiliary pipelines are installed on the loading and unloading skid body. The auxiliary pipelines include a vent pipeline, a drain pipeline, and a nitrogen purging and protection pipeline. Its characteristics are:

[0005] A loading and unloading pipeline system for realizing integrated loading and unloading is installed on the loading and unloading skid body. The loading and unloading pipeline system includes a vapor phase pipeline, a liquid phase loading pipeline, a liquid phase unloading pipeline, and a vaporization and pressurization pipeline;

[0006] The upstream end of the vapor phase pipeline is provided with an interface Ⅰ for connecting with the LNG vapor phase main pipeline, and the downstream end is provided with an interface Ⅱ for connecting with the vapor phase loading and unloading arm. A manual ball valve Ⅰ and a switch valve Ⅰ are sequentially arranged on the vapor phase pipeline from the upstream end to the downstream end;

[0007] The upstream end of the liquid phase loading pipeline is provided with an interface Ⅲ for connecting with the liquid phase outlet pipeline of the LNG storage tank, and the downstream end is connected to the liquid phase loading and unloading arm through a receiving and discharging main pipe. A manual ball valve Ⅱ, a mass flowmeter, a flow regulating valve Ⅰ, a switch valve Ⅱ, and a check valve Ⅰ are sequentially arranged on the liquid phase loading pipeline from the upstream end to the downstream end;

[0008] The liquid unloading pipeline includes a direct unloading pipeline. The upstream end of the direct unloading pipeline is provided with an interface Ⅳ for connecting to the liquid inlet pipeline of the LNG storage tank, and the downstream end is connected to the unloading main pipe. The direct unloading pipeline is successively provided with a manual ball valve Ⅲ, a flow regulating valve Ⅱ, a check valve Ⅱ, and a switch valve Ⅲ from the upstream end to the downstream end; in parallel between the downstream of the flow regulating valve Ⅱ of the direct unloading pipeline and the unloading main pipe is a pump unloading pipeline, and the pump unloading pipeline is successively provided with a check valve Ⅲ, a metal hose Ⅰ, a cryogenic pump, a metal hose Ⅱ, a filter, and a switch valve Ⅳ from the upstream end to the downstream end;

[0009] An evaporation booster is installed on the evaporation boosting pipeline. One end of the evaporation booster is connected to the gas pipeline through a check valve Ⅳ, and the other end is provided with a liquid introduction interface;

[0010] (1) Loading process: The LNG liquid medium enters the liquid loading pipeline through interface Ⅲ, enters the tank truck through the liquid loading and unloading arm, and the gas medium generated in the tank truck enters the gas pipeline through the gas loading and unloading arm and enters the LNG gas main pipeline from interface Ⅰ;

[0011] (2) Self-pressurizing unloading process: The LNG liquid medium enters the evaporation boosting pipeline from the liquid introduction interface, the vaporized gas medium enters the gas pipeline, enters the tank truck through the gas loading and unloading arm to pressurize the tank truck. After the liquid medium enters the unloading main pipe through the liquid loading and unloading arm, it enters the direct unloading pipeline and enters the LNG storage tank from interface Ⅳ;

[0012] (3) Cryogenic pump unloading process: Under the action of the cryogenic pump, the LNG liquid medium enters the unloading main pipe through the liquid loading and unloading arm, then enters the pump unloading pipeline, and enters the LNG storage tank from interface Ⅳ. At the same time, the gas pipeline is opened to replenish pressure to the tank truck through the gas loading and unloading arm;

[0013] (4) Self-pressurizing and cryogenic pump simultaneous unloading process: The LNG liquid medium enters the evaporation boosting pipeline from the liquid introduction interface, the vaporized gas medium enters the gas pipeline, enters the tank truck through the gas loading and unloading arm to pressurize the tank truck. After the liquid medium enters the unloading main pipe through the liquid loading and unloading arm, it enters the direct unloading pipeline and enters the LNG storage tank from interface Ⅳ; at the same time, under the action of the cryogenic pump, the LNG liquid medium enters the unloading main pipe through the liquid loading and unloading arm, then enters the pump unloading pipeline, and enters the LNG storage tank from interface Ⅳ.

[0014] The technical problem to be solved by the present invention can also be further realized by the following technical solution. A manual ball valve Ⅳ is provided in parallel with the flow regulating valve Ⅰ on the liquid loading line, and a manual ball valve Ⅴ is provided in parallel with the flow regulating valve Ⅱ on the direct unloading pipeline.

[0015] The technical problem to be solved by the present invention can also be further realized by the following technical solution. A bypass branch is provided in parallel on the pump unloading pipeline between the downstream of the check valve Ⅲ and the downstream of the filter, and a manual ball valve Ⅵ is provided on the bypass branch.

[0016] The technical problem to be solved by the present invention can also be further achieved by the following technical solution. An internal connection pipeline and an external connection pipeline are provided at the liquid guiding interface. The internal connection pipeline is connected to the unloading main pipeline through a manual ball valve VII, and the downstream end of the external connection pipeline is provided with an external connection interface, and a manual ball valve VIII is provided on the external connection pipeline.

[0017] The technical problem to be solved by the present invention can also be further achieved by the following technical solution. The gas-phase loading and unloading arm, the liquid-phase loading and unloading arm, the gas-phase pipeline, the unloading main pipeline, the direct unloading pipeline, the pump unloading pipeline, and the vaporization and pressurization pipeline are all connected to the vent pipeline through a conversion valve group.

[0018] The technical problem to be solved by the present invention can also be further achieved by the following technical solution. A connecting pipeline is provided between the downstream of the flow regulating valve I of the liquid-phase loading pipeline and the downstream of the check valve II of the direct unloading pipeline, and a manual ball valve IX is provided on the connecting pipeline.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: By combining the liquid-phase loading pipeline and the liquid-phase unloading pipeline, the single skid-mounted device can realize the functions of loading or unloading according to needs. At the same time, the setting of the direct unloading pipeline and the pump unloading pipeline realizes the dual-purpose process of cryogenic pump unloading and vaporizer pressurization unloading, saving production costs and having good social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] The following further describes the specific technical solution of the present invention to facilitate those skilled in the art to further understand the present invention without limiting its rights. Embodiment

[0022] An LNG loading and unloading integrated skid-mounted device includes a set of LNG loading and unloading arms and a skid-mounted device body. The LNG loading and unloading arms include a gas-phase loading and unloading arm and a liquid-phase loading and unloading arm. Auxiliary pipelines are installed on the skid-mounted device body, and the auxiliary pipelines include a vent pipeline, a drainage pipeline, and a nitrogen purging and protection pipeline.

[0023] An unloading pipeline system for realizing integrated loading and unloading is installed on the skid-mounted device body. The unloading pipeline system includes a gas-phase pipeline, a liquid-phase loading pipeline, a liquid-phase unloading pipeline, and a vaporization and pressurization pipeline;

[0024] The upstream end of the gas-phase pipeline is provided with an interface I 70 for connecting to the LNG gas-phase main pipeline, and the downstream end is provided with an interface II 83 for connecting to the gas-phase loading and unloading arm. The gas-phase pipeline is sequentially provided with a manual ball valve I 17 and a switch valve I 16 from the upstream end to the downstream end;

[0025] The upstream end of the liquid loading pipeline is provided with an interface Ⅲ71 for connecting with the liquid outlet pipeline of the LNG storage tank, and the downstream end is connected to the liquid loading and unloading arm through a receiving and unloading main pipe. The liquid loading pipeline is successively provided with a manual ball valve Ⅱ36, a mass flowmeter 35, a flow regulating valve Ⅰ34, a switch valve Ⅱ33, and a check valve Ⅰ32 from the upstream end to the downstream end;

[0026] The liquid unloading pipeline includes a direct unloading pipeline. The upstream end of the direct unloading pipeline is provided with an interface Ⅳ72 for connecting with the liquid inlet pipeline of the LNG storage tank, and the downstream end is connected to the receiving and unloading main pipe. The direct unloading pipeline is successively provided with a manual ball valve Ⅲ42, a flow regulating valve Ⅱ41, a check valve Ⅱ40, and a switch valve Ⅲ39 from the upstream end to the downstream end; A pump unloading pipeline is connected in parallel between the downstream of the flow regulating valve Ⅱ41 of the direct unloading pipeline and the receiving and unloading main pipe. The pump unloading pipeline is successively provided with a check valve Ⅲ53, a metal hose Ⅰ52, a cryogenic pump 51, a metal hose Ⅱ50, a filter 49, and a switch valve Ⅳ48 from the upstream end to the downstream end;

[0027] A vaporization booster is installed on the vaporization boosting pipeline. One end of the vaporization booster is connected to the gas pipeline through a check valve Ⅳ31, and the other end is provided with a liquid guiding interface;

[0028] (1) Loading process: The LNG liquid medium enters the liquid loading pipeline from the interface Ⅲ71, enters the tank truck through the liquid loading and unloading arm, and the gas medium generated in the tank truck enters the gas pipeline through the gas loading and unloading arm and enters the LNG gas main pipeline from the interface Ⅰ70;

[0029] (2) Self-pressurizing unloading process: The LNG liquid medium enters the vaporization boosting pipeline from the liquid guiding interface, the vaporized gas medium enters the gas pipeline, enters the tank truck through the gas loading and unloading arm to pressurize the tank truck. After the liquid medium enters the receiving and unloading main pipe through the liquid loading and unloading arm, it enters the direct unloading pipeline and enters the LNG storage tank from the interface Ⅳ72;

[0030] (3) Cryogenic pump unloading process: Under the action of the cryogenic pump, the LNG liquid medium enters the receiving and unloading main pipe through the liquid loading and unloading arm, then enters the pump unloading pipeline and enters the LNG storage tank from the interface Ⅳ72. At the same time, the gas pipeline is opened to replenish pressure to the tank truck through the gas loading and unloading arm;

[0031] (4) Self-pressurizing and cryogenic pump simultaneous unloading process: The LNG liquid medium enters the vaporization boosting pipeline from the liquid guiding interface, the vaporized gas medium enters the gas pipeline, enters the tank truck through the gas loading and unloading arm to pressurize the tank truck. After the liquid medium enters the receiving and unloading main pipe through the liquid loading and unloading arm, it enters the direct unloading pipeline and enters the LNG storage tank from the interface Ⅳ72. At the same time, under the action of the cryogenic pump, the LNG liquid medium enters the receiving and unloading main pipe through the liquid loading and unloading arm, then enters the pump unloading pipeline and enters the LNG storage tank from the interface Ⅳ72.

[0032] A manual ball valve Ⅳ38 is set in parallel with the flow regulating valve Ⅰ34 on the liquid loading line, and a manual ball valve Ⅴ54 is set in parallel with the flow regulating valve Ⅱ41 on the direct unloading line.

[0033] A bypass branch is provided in parallel on the pump unloading line between the downstream of the check valve Ⅲ53 and the downstream of the filter 49, and a manual ball valve Ⅵ55 is provided on the bypass branch.

[0034] An internal connecting pipe and an external connecting pipe are provided at the liquid introduction interface. The internal connecting pipe is connected to the receiving and unloading main pipe through a manual ball valve Ⅶ42. The downstream end of the external connecting pipe is provided with an external interface, and a manual ball valve Ⅷ57 is provided on the external connecting pipe.

[0035] The gas loading and unloading arm, the liquid loading and unloading arm, the gas pipeline, the receiving and unloading main pipe, the direct unloading pipeline, the pump unloading pipeline, and the vaporization and pressurization pipeline are all connected to the vent pipeline through a conversion valve group.

[0036] A connecting pipeline is provided between the downstream of the flow regulating valve Ⅰ34 on the liquid loading pipeline and the downstream of the check valve Ⅱ40 on the direct unloading pipeline, and a manual ball valve Ⅸ37 is provided on the connecting pipeline.

[0037] The upstream end of the gas loading and unloading arm is provided with an interface 77 docked with the interface 83, and the downstream is docked with the gas interface 01 of the LNG tank truck; the gas loading and unloading arm is sequentially provided with a manual ball valve 11 and a breakaway valve 04 from the upstream end to the downstream end; the upstream of the liquid loading and unloading arm is provided with an interface 80 docked with the receiving and unloading main pipe, and the downstream is docked with the liquid interface 02 of the LNG tank truck; the liquid loading and unloading arm is sequentially provided with a manual ball valve 12 and a breakaway valve 05 from the upstream end to the downstream end.

[0038] The nitrogen purging and protection pipeline includes a purging pipeline. The upstream end of the purging pipeline is provided with an interface Ⅴ74 for connecting to the nitrogen pipeline, and the downstream end is respectively connected to the gas loading and unloading arm and the liquid loading and unloading arm. The purging pipeline is sequentially provided with a manual ball valve Ⅹ63, a filter Ⅱ62, a self-operated pressure regulating valve Ⅰ61, and a check valve Ⅴ60 from the upstream end to the downstream end. The nitrogen purging pipeline downstream of the check valve Ⅴ60 is divided into two branches to form a gas loading and unloading arm purging branch line and a liquid loading and unloading arm purging branch line.

[0039] A protection pipeline is provided downstream of the self-operated pressure regulating valve 61 on the purging pipeline. The downstream end of the protection pipeline is communicated with each nitrogen interface of the LNG loading and unloading arm swivel joint. The protection pipeline is sequentially provided with a manual ball valve Ⅺ66, a check valve Ⅵ65, and a self-operated pressure regulating valve Ⅱ64 from the upstream end to the downstream end.

[0040] Seven vent interfaces for connecting the vent pipeline are respectively provided on the gas-phase loading and unloading arm, liquid-phase loading and unloading arm, gas-phase pipeline, receiving and discharging main pipeline, direct unloading pipeline, pump unloading pipeline, and vaporization booster pipeline. The vent interface I is arranged on the gas-phase loading and unloading arm; the vent interface II is arranged on the liquid-phase loading and unloading arm; the vent interface III is arranged on the vaporization booster pipeline between the manual ball valve VIII 57 and the vaporizer 58; the vent interface IV is arranged on the receiving and discharging main pipeline; the vent interface V is arranged on the gas-phase pipeline between the interface II 83 and the on-off valve 16; the vent interface VI is arranged on the liquid-phase loading pipeline between the on-off valve II 33 and the flow regulating valve I 34; the vent interface VII is arranged on the direct unloading pipeline between the check valve II 40 and the flow regulating valve II 41. The seven vent interfaces are all connected to the vent pipeline through vent branch lines, and a conversion valve group is provided on the vent branch line. The conversion valve group includes a first manual ball valve, a safety valve, and a second manual ball valve connected in series. The first manual ball valve and the second manual ball valve are in the normally open state. When the medium exceeds the set pressure, the safety valve automatically opens, and the medium flows to the vent pipeline for venting. A bypass manual ball valve is provided in front of the first manual ball valve and behind the second manual ball valve for venting the medium in the vent pipeline during maintenance operations.

[0041] One end of the drain pipeline is led out from the receiving and discharging main pipeline and is used to drain the liquid-phase medium in the pipeline.

[0042] When the LNG loading and unloading integrated skid is not working, to prevent the pipeline from freezing, open the manual ball valve 37 to introduce a small amount of LNG liquid-phase medium into the liquid-phase loading pipeline and the direct unloading pipeline. The LNG liquid-phase medium is introduced from the interface III 71 and flows through the manual ball valve II 36, flowmeter 35, manual ball valve IV 38, manual ball valve IX 37, check valve II 40, manual ball valve V 54, and manual ball valve III 42 in sequence, and finally discharges from the interface IV 72.

Claims

1. An integrated LNG loading and unloading skid, comprising a set of LNG loading and unloading arms and a loading and unloading skid body. The LNG loading and unloading arms include a vapor loading and unloading arm and a liquid loading and unloading arm. An auxiliary pipeline is installed on the loading and unloading skid body. The auxiliary pipeline includes a vent pipeline, a drainage pipeline, and a nitrogen purging and protection pipeline. It is characterized in that: A loading and unloading pipeline system for realizing integrated loading and unloading is installed on the loading and unloading skid body. The loading and unloading pipeline system includes a vapor pipeline, a liquid loading pipeline, a liquid unloading pipeline, and a vaporization and pressurization pipeline; The upstream end of the vapor pipeline is provided with an interface I for connecting to the LNG vapor main pipeline, and the downstream end is provided with an interface II for connecting to the vapor loading and unloading arm. The vapor pipeline is sequentially provided with a manual ball valve I and a switch valve I from the upstream end to the downstream end; The upstream end of the liquid loading pipeline is provided with an interface III for connecting to the liquid outlet pipeline of the LNG storage tank, and the downstream end is connected to the liquid loading and unloading arm through a receiving and discharging main pipe. The liquid loading pipeline is sequentially provided with a manual ball valve II, a mass flowmeter, a flow regulating valve I, a switch valve II, and a check valve I from the upstream end to the downstream end; The liquid unloading pipeline includes a direct unloading pipeline. The upstream end of the direct unloading pipeline is provided with an interface IV for connecting to the liquid inlet pipeline of the LNG storage tank, and the downstream end is connected to the receiving and discharging main pipe. The direct unloading pipeline is sequentially provided with a manual ball valve III, a flow regulating valve II, a check valve II, and a switch valve III from the upstream end to the downstream end; A pump unloading pipeline is connected in parallel between the downstream of the flow regulating valve II of the direct unloading pipeline and the receiving and discharging main pipe. The pump unloading pipeline is sequentially provided with a check valve III, a metal hose I, a cryogenic pump, a metal hose II, a filter, and a switch valve IV from the upstream end to the downstream end; A vaporization and pressurization device is installed on the vaporization and pressurization pipeline. One end of the vaporization and pressurization device is connected to the vapor pipeline through a check valve IV, and the other end is provided with a liquid guiding interface; A manual ball valve IV is provided in parallel with the flow regulating valve I on the liquid loading pipeline, and a manual ball valve V is provided in parallel with the flow regulating valve II on the direct unloading pipeline; A bypass branch is connected in parallel on the pump unloading pipeline between the downstream of the check valve III and the downstream of the filter, and a manual ball valve VI is provided on the bypass branch; (1) Loading process: The LNG liquid medium enters the liquid loading pipeline from the interface III, enters the tank truck through the liquid loading and unloading arm. The vapor medium generated in the tank truck enters the vapor pipeline through the vapor loading and unloading arm and enters the LNG vapor main pipeline from the interface I; (2) Self-pressurization unloading process: The LNG liquid medium enters the vaporization and pressurization pipeline from the liquid guiding interface. The vaporized vapor medium enters the vapor pipeline, enters the tank truck through the vapor loading and unloading arm to pressurize the tank truck. After the liquid medium enters the receiving and discharging main pipe through the liquid loading and unloading arm, it enters the direct unloading pipeline and enters the LNG storage tank from the interface IV; (3) Cryogenic pump unloading process: Under the action of the cryogenic pump, the LNG liquid medium enters the receiving and discharging main pipe through the liquid loading and unloading arm, then enters the pump unloading pipeline, and enters the LNG storage tank from the interface IV. At the same time, the vapor pipeline is opened to replenish pressure to the tank truck through the vapor loading and unloading arm; (4)Self-pressurizing and cryogenic pump simultaneous unloading process: The LNG liquid-phase medium enters the vaporization and pressurization pipeline from the liquid-introducing interface. The vaporized gas-phase medium enters the gas pipeline and then enters the tank truck through the gas loading and unloading arm to pressurize the tank truck. The liquid-phase medium enters the receiving and unloading main pipe through the liquid loading and unloading arm, then enters the direct unloading pipeline and enters the LNG storage tank from Interface IV. At the same time, under the action of the cryogenic pump, the LNG liquid-phase medium enters the receiving and unloading main pipe through the liquid loading and unloading arm, then enters the pump unloading pipeline and enters the LNG storage tank from Interface IV.

2. The integrated LNG loading and unloading skid according to claim 1, wherein: An internal connection pipeline and an external connection pipeline are provided at the liquid-introducing interface. The internal connection pipeline is connected to the receiving and unloading main pipe through manual ball valve VII. The downstream end of the external connection pipeline is provided with an external connection interface, and manual ball valve VIII is provided on the external connection pipeline.

3. The integrated LNG loading and unloading skid according to claim 1, characterized in that: The gas loading and unloading arm, liquid loading and unloading arm, gas pipeline, receiving and unloading main pipe, direct unloading pipeline, pump unloading pipeline, and vaporization and pressurization pipeline are all connected to the vent pipeline through a conversion valve group.

4. The integrated LNG loading and unloading skid according to claim 1, wherein: A connection pipeline is provided between the downstream of flow control valve I in the liquid loading pipeline and the downstream of check valve II in the direct unloading pipeline, and manual ball valve IX is provided on the connection pipeline.

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