Submarine Pit Gravity Flow Type ORV Gasification System and Method

Abstract

The present invention provides a foundation pit type seawater gravity flow type ORV gasification system and method, including: a foundation pit arranged by the sea, with a water inlet provided at the upper part of one side thereof, the water inlet being lower than the sea level and communicating with a seawater inlet pipeline, and a seawater regulating valve being provided on the seawater inlet pipeline; an ORV heat exchange plate located below the liquid level in the foundation pit and capable of exchanging heat with the seawater in the foundation pit; a liquefied natural gas pipeline communicating with the bottom of the ORV heat exchange plate to supply liquefied natural gas to the ORV heat exchange plate; a natural gas outlet pipe communicating with the top of the ORV heat exchange plate to send the gasified natural gas downstream; and a seawater discharge pump arranged in the foundation pit for discharging the seawater in the foundation pit. The present invention cancels the seawater pump system and directly enables seawater to enter the foundation pit by gravity flow to exchange heat with the ORV by setting the foundation pit, greatly simplifying the process flow and reducing the project investment.

Description

Technical Field

[0001] The present invention relates to an ORV gasification system and method in an LNG receiving terminal. Background Art

[0002] In an LNG receiving terminal, an open rack vaporizer (ORV) system is generally configured in the gasification unit. The open rack vaporizer uses a seawater pump and a seawater pipeline to transport seawater to bilateral or unilateral water tanks at the upper part of the vaporizer. The seawater overflows from both sides of the water tank to the surface of the heat exchange tubes and exchanges heat with the liquid LNG inside the heat exchange tubes, thereby gasifying the LNG.

[0003] In the existing technical solutions, it is necessary to configure a seawater pump, a water intake, a drainage ditch, a seawater pipeline, etc. Among them, the power of the seawater pump needs to be large enough, and the seawater pipeline needs to be long enough. Therefore, the cost cannot be reduced, and there are technical problems such as a very complex process flow, huge engineering investment, and serious energy waste.

[0004] Generally speaking, the disadvantages of the existing system include:

[0005] 1. The project volume is huge and the investment is relatively high;

[0006] 2. The process flow is complex and the energy consumption is large;

[0007] 3. The control scheme is relatively complex;

[0008] 4. It is necessary to equip a seawater pump, resulting in energy consumption;

[0009] 5. It is necessary to configure underground structures such as a water intake and a seawater ditch;

[0010] 6. It is necessary to configure facilities such as a seawater pipeline and an underground pipe trench;

[0011] 7. The maintenance of the underground seawater pipeline is inconvenient. Summary of the Invention

[0012] The purpose of the present invention is to provide a foundation pit type seawater gravity flow type ORV gasification system and method to solve the above technical problems existing in the prior art.

[0013] To achieve the above purpose, the technical solution adopted by the present invention is:

[0014] A foundation pit type seawater gravity flow type ORV gasification system, characterized in that it includes:

[0015] A foundation pit, with a water inlet provided at the upper part of one side thereof. The water inlet is lower than the sea level and is connected to a seawater inlet pipeline, and a seawater regulating valve is provided on the seawater inlet pipeline;

[0016] An ORV heat exchange plate, located below the liquid level in the foundation pit, capable of exchanging heat with the seawater in the foundation pit;

[0017] The liquefied natural gas pipeline is connected to the bottom of the ORV heat exchange plate to supply liquefied natural gas to the ORV heat exchange plate;

[0018] The natural gas outlet pipe is connected to the top of the ORV heat exchange plate to send the gasified natural gas downstream;

[0019] The seawater discharge pump is arranged in the foundation pit and is used to discharge the seawater in the foundation pit.

[0020] For the foundation pit type seawater gravity flow type ORV gasification system, wherein: the seawater discharge pump is a submersible seawater pump or a vertical long shaft pump.

[0021] For the foundation pit type seawater gravity flow type ORV gasification system, wherein: a liquid level gauge is further provided in the foundation pit, and the liquid level gauge is signal-connected to the seawater discharge pump.

[0022] For the foundation pit type seawater gravity flow type ORV gasification system, wherein: a flow meter and a thermometer are provided on the natural gas outlet pipe, and both the flow meter and the thermometer are signal-connected to the flow regulating valve on the liquefied natural gas pipeline.

[0023] For the foundation pit type seawater gravity flow type ORV gasification system, wherein: it further includes a blower, an air volume regulating valve, an air pipeline and an air distribution pipe connected in sequence, and the air distribution pipe is arranged in the foundation pit at a position below the ORV heat exchange plate.

[0024] A foundation pit type seawater gravity flow type ORV gasification method using the foundation pit type seawater gravity flow type ORV gasification system, characterized in that:

[0025] Seawater enters the foundation pit through the seawater inlet pipeline by gravity and submerges the ORV heat exchange plate;

[0026] Liquefied natural gas enters the ORV heat exchange plate through the liquefied natural gas pipeline, exchanges heat with the seawater in the foundation pit through the ORV heat exchange plate, and after being converted into natural gas, the natural gas is sent downstream through the natural gas outlet pipe.

[0027] Compared with the prior art, the beneficial effects of the present invention are: the present invention cancels the seawater pump system, and by setting the foundation pit, the seawater directly enters the foundation pit by gravity flow to exchange heat with the ORV, greatly simplifying the process flow and reducing the project investment. Brief Description of the Drawings

[0028] Figure 1 It is a schematic structural diagram of the present invention.

[0029] Description of reference numerals: foundation pit 1; seawater inlet pipeline 2; seawater regulating valve 3; ORV heat exchange plate 4; liquefied natural gas pipeline 5; flow regulating valve 51; natural gas outlet pipe 6; seawater discharge pump 7; liquid level gauge 8; thermometer 9; flowmeter 10; air inlet 11; filter 12; fan 13; air volume regulating valve 14; air pipeline 15; air distribution pipe 16. Detailed implementation mode

[0030] As Figure 1 shown, the present invention provides a foundation pit type seawater gravity flow type ORV gasification system, including:

[0031] A foundation pit 1 is arranged by the sea (the closer the better to save energy consumption). There is a water inlet at the upper part of one side of the foundation pit 1. The water inlet is lower than the sea level and is connected to the seawater inlet pipeline 2. A seawater regulating valve 3 is arranged on the seawater inlet pipeline 2 to control the speed of seawater flowing into the foundation pit 1;

[0032] An ORV heat exchange plate 4 is located below the liquid level in the foundation pit 1 and can fully exchange heat with the seawater in the foundation pit 1;

[0033] A liquefied natural gas pipeline 5 is connected to the bottom of the ORV heat exchange plate 4 to supply liquefied natural gas to the ORV heat exchange plate 4. The liquefied natural gas exchanges heat with the seawater in the foundation pit 1 through the ORV heat exchange plate 4 and is converted into natural gas;

[0034] A natural gas outlet pipe 6 is connected to the top of the ORV heat exchange plate 4 to send the natural gas downstream for storage and transportation;

[0035] A seawater discharge pump 7, preferably a seawater submersible pump or a vertical long shaft pump, is arranged in the foundation pit 1 and is used to discharge the seawater in the foundation pit 1 into the sea to reasonably adjust the water level in the foundation pit 1.

[0036] When the present invention is used, seawater added with sodium hypochlorite solution (producing sodium hypochlorite solution by electrolyzing seawater and adding it to the seawater to prevent marine organisms from growing and blocking pipelines and equipment and affecting the normal operation of the seawater system) enters the foundation pit 1 through the seawater inlet pipeline 2 by gravity, submerging the ORV heat exchange plate 4. The liquefied natural gas enters the ORV heat exchange plate 4 through the liquefied natural gas pipeline 5 and exchanges heat with the seawater in the foundation pit 1 through the ORV heat exchange plate 4. After being converted into natural gas, the natural gas is sent downstream for storage and transportation through the natural gas outlet pipe 6.

[0037] Among them, the speed of seawater entering the foundation pit 1 can be controlled by the seawater regulating valve 3 to avoid too low water level; the water level in the foundation pit 1 can be controlled by the seawater discharge pump 7 to avoid too high water level.

[0038] Moreover, a liquid level gauge 8 is also provided in the foundation pit 1. The liquid level gauge 8 is signal-connected to the seawater discharge pump 7, and when the liquid level in the foundation pit 1 is too high, the seawater discharge pump 7 can be started automatically.

[0039] In addition, a thermometer 9 and a flowmeter 10 are provided on the natural gas outlet pipe 6. The thermometer 9 and the flowmeter 10 are both signal-connected to the flow regulating valve 51 on the liquefied natural gas pipeline 5. By relying on the flow rate and temperature values of the natural gas outlet pipe 6, the flow rate of the liquefied natural gas is adjusted, and the gasification speed can be maintained in the high-efficiency range.

[0040] Moreover, as Figure 1 shown, the present invention can also be provided with an air distribution system, which includes an air inlet 11, a filter 12, a fan 13, an air volume regulating valve 14, an air pipeline 15 and an air distribution pipe 16 connected in sequence. The air distribution pipe 16 is arranged in the foundation pit 1 at a position below the ORV heat exchange plate 4. Driven by the fan 13, compressed air enters the air distribution pipe 16 and then forms bubbles and discharges from the air distribution pipe 16. A large number of bubbles can greatly disturb the seawater in the foundation pit 1 and further improve the heat exchange efficiency between the seawater and the ORV heat exchange plate 4.

[0041] As described above, the present invention can achieve the following technical effects:

[0042] 1. The process is simple and the control is easy;

[0043] 2. The project quantity is small and the investment is saved;

[0044] 3. It is green, environmentally friendly, energy-saving and consumption-reducing;

[0045] 4. The heat exchange efficiency is high.

[0046] The above description is illustrative rather than restrictive to the present invention. Those of ordinary skill in the art understand that many modifications, changes or equivalents can be made without departing from the spirit and scope defined by the claims, but all of them will fall within the protection scope of the present invention.

Claims

1. A pit-type seawater gravity flow ORV gasification system, characterized in that, Comprising: A foundation pit, with a water inlet provided at the upper part of one side thereof. The water inlet is below sea level and is connected to a seawater inlet pipeline, and a seawater regulating valve is provided on the seawater inlet pipeline; An ORV heat exchange plate, located below the liquid level in the foundation pit, capable of exchanging heat with the seawater in the foundation pit; A liquefied natural gas pipeline, connected to the bottom of the ORV heat exchange plate to supply liquefied natural gas to the ORV heat exchange plate; A natural gas outlet pipe, connected to the top of the ORV heat exchange plate to send the gasified natural gas downstream; a flow meter and a thermometer are provided on the natural gas outlet pipe, and both the flow meter and the thermometer are signal-connected to the flow regulating valve on the liquefied natural gas pipeline; A seawater discharge pump, arranged in the foundation pit for discharging the seawater in the foundation pit; a liquid level gauge is also provided in the foundation pit, and the liquid level gauge is signal-connected to the seawater discharge pump; This foundation pit type seawater gravity flow type ORV gasification system cancels the seawater pump system. By setting the foundation pit, seawater directly enters the foundation pit through gravity flow to exchange heat with the ORV heat exchange plate.

2. The pit-type seawater gravity flow ORV gasification system according to claim 1, characterized in that: The seawater discharge pump is a seawater submersible pump or a vertical long shaft pump.

3. The ORV gasification system of the foundation pit type seawater gravity flow according to claim 1, wherein: It further comprises a blower, an air volume regulating valve, an air pipeline and an air distribution pipe which are connected in sequence. The air distribution pipe is arranged in the foundation pit at a position below the ORV heat exchange plate.

4. A foundation pit type seawater gravity flow type ORV gasification method, using the foundation pit type seawater gravity flow type ORV gasification system according to any one of claims 1-3, characterized in that: Seawater enters the foundation pit through the seawater inlet pipeline by gravity, submerging the ORV heat exchange plate; Liquefied natural gas enters the ORV heat exchange plate through the liquefied natural gas pipeline, exchanges heat with the seawater in the foundation pit through the ORV heat exchange plate, and after being converted into natural gas, the natural gas is sent downstream through the natural gas outlet pipe.

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